LIBRARY Michigan State University PLACE ll RETURN Boxwomnovuhbmm yourrococd. TOAVOID FINESMumonorbdoroddodm. DATE DUE DATE DUE DATE DUE usuummmmmmdomnm 1 POLYCYCLIC AROMATIC HYDROCARBONS: PARTITIONING TO LAKE MICHIGAN SEDIMENT By Leif Krag Rowles A Thesis Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Civil and Environmental Engineering 1994 ABSTRACT POLYCYCLIC AROMATIC HYDROCARBONS: PARTITIONING TO LAKE MICHIGAN SEDIMENT By Leif Krag Rowles Experimental batch absorption studies were completed to evaluate the apparent solid phase organic carbon partitioning coefficient of four PAH compounds to Lake Michigan Sediment. The experiments were conducted over a range of solid concentrations to study the concept of a solid effect. Additionally, partitioning coefficients for phenanthrene and benzo-a-pyrene were determined for the aqueous phase distribution in terms of "free" and "bound" by using the reverse phase and the fluorescence quenching techniques which have been developed by other researchers. Data obtained for benzo-a-pyrene using both a constant and varying solid technique suggested that heterogeneous sorption was occurring. This data was calibrated to the Solute Complexation Model developed by Voice, 1985. A non-linear parameter estimation technique was attempted to estimate both the aqueous "free" and "bound" solid phase sorption coefficients which are conceptualized in the model. TABLE OF CONTENTS List of Tables List of Figures List of Symbols Introduction Chapter 1: Theory and Background 1.1 1.2 1.3 1.4 1.5 1.6 Introduction Hydrophobic Sorption and Evaluation of Partitioning Data The Relationship Between Observed Partitioning and Solids Concentration Three Phase Modeling Equilibrium partitioning Solute Complexation Model Chapter II: PAH sorption Experiments 2.1 2.2 Introduction Materials and Methods 2.2.1 Sediment Sampling 2.2.2 Batch Sorption Experiments iii vi viii 15 16 17 23 26 26 28 2.3 2.4 TABLE OF CONTENTS (continued) Results and Discussion: Solid Phase Sorption Conclusions: PAH Sorption Experiments Chapter III: Measurement of Phenanthrene and Benzo-a—pyrene Binding to Lake Michigan Sediments Introduction 3.1 3.2 3.3 3.4 Quantifying DOC Released from Lake Michigan Sediments 3.2.1 Materials and Methods 3.2.2 Results and Discussion Fluorescence Quenching 3.3.1 Methods and Materials for Fluorescence Quenching Measurements of Phenanthrene and Benzo-a-pyrene 3.3.2 Results and Discussion: Calculation of Kdoc 3.3.3 Conclusions: Fluorescence Quenching Reverse Phase Separation 3.4.1 Materials and Methods: Emporer Disk Extraction 3.4.2 Results and Discussion: Emporer Disk Extraction 3.4.3 Conclusions: Emporer Disk Extraction Chapter IV: Modeling Benzo-a-pyrene Sorption to Lake Michigan Sediments Using the Solute Complexation Model iv 54 56 56 58 59 66 69 74 79 83 85 89 92 95 TABLE OF CONTENTS (continued) 4.1 Introduction 4.2 Results and Discussion 4.2.1 Model Calibration 4.2.2 N on-linear Parameter Estimation 4.2.3 Conclusions Future Research Reference List 95 96 96 112 115 117 . 118 LIST OF TABLES Introduction Table 1.1: Polycyclic Aromatic Hydrocarbon Properties 3 Chapter II: PAH Sorption Experiments Table 2.1: Radiolabelled PAH Data 31 Table 2.2: Phenanthrene Partitioning Data 35 Table 2.3: Fluoranthene Partitioning Data 36 Table 2.4 Pyrene Partitioning Data 37 Table 2.5 Benzo-a-pyrene Partitioning Data 38 Table 2.6 Benzo-a-pyrene Partitioning Data 39 Table 2.7 Confidence in Benzo—a-pyrene Activity Measurements 41 Chapter H1: Measurement of Phenanthrene and Benzo-a-pyrene Binding to Dissolved Organic Carbon from Lake Michigan Sediments Table 3.1 Fluorescence Quenching, Phenanthrene 75 Table 3.2 Fluorescence Quenching, Benzo-a-pyrene 77 Table 3.3 Reverse Phase Separation, Phenanthrene 90 Table 3.4 Reverse Phase Separation, Benzo-a-pyrene 91 vi Appendices Table A.1 Table D.1 Table D2 Table E.1 Table E.2 Table E.3 Benzo-a-pyrene Timed Fluorescence Data Benzo-a-pyrene, Non-linear parameter Estimation SystatR Parameter Estimation, K1 and K2 Phenanthrene Dialysis with AldrichR Humic Acid Photometric Data, Phenanthrene Dialysis l4C Activity Measurements, Phenanthrene Dialysis vii 124 144 145 148 151 152 Chapter I: Figure 1.1: Figure 1.2: Figure 1.3: Figure 1.4: Figure 1.5: Figure 2.1: Figure 2.2: Figure 2.3: Figure 2.4: Figure 2.5: Figure 2.6: Figure 2.7: Figure 2.8: LIST OF FIGURES Theory and Background Grand Calumet River Data: PAI-I‘s, K0c vs foc Grand Calumet River Data: PAH‘s, K0c vs foe Grand Calumet DOC vs foc Schematic of Solute Complexation Model Effect of Isothenn Procedure for Heterogeneous Solute Chapter II: PAH Sorption Experiments Sampling Locations Procedure Flow Chart Radiolabelled Compound Purification Pyrene Kinetic Data K0,; vs Sediment Concentration: Fluoranthene Recovery of Fluoranthene from Sediment Fluoranthene sorption Data . PAH Sorption Data viii 11 12 14 18 2O 27 29 30 33 43 47 48 List of Figures (continued) Figure 2.9: Effect of Isotherm Procedure on Observed Partitioning for a Heterogeneous Solute 50 Figure 2.10: Phenanthrene Absorption Isotherm 51 Figure 2.11: Benzo-a-pyrene Absorption Isotherm 53 Chapter III: Measurement of Phenanthrene and Benzo-a-pyrene Binding to Dissolved Organic Carbon from Lake Michigan Sediments Figure 3.1: Release of Organic Carbon from Sediments 61 Figure 3.2: Absorbance at 255 nm vs Sediment Concentration 62 Figure 3.3: TOC vs Absorbance at 255 nm 64 Figure 3.4: TOC and Turbidity vs Absorbance 65 Figure 3.5: Phenanthrene Fluorescence Spectra 71 Figure 3.6 Benzo-a-pyrene Fluorescence Extrapolation 73 Figure 3.7: Phenanthrene Reverse Phase and Fluorescence, Kdoc 81 Figure 3.8: Benzo-a-pyrene Reverse Phase and Fluorescence, Kdoc 82 Figure 3.9: Flow-rate through Empore Disk 87 Figure 3.10: Benzo-a-pyrene, Corrected K0c 94 Chapter IV: Modeling Benzo-a-pyrene Sorption to Lake Michigan Sediments Using the Solute Complexation Model Figure 4.1: Schematic of Solute Complexation Model 97 ix Figure 4.2: Figure 4.3: Figure 4.4: Figure 4.5: Figure 4.6: Figure 4.7: Figure 4.8: Figure 4.9: Figure 4.10: Figure 4.11: Appendices Figure 13.1 Figure E.2 List of Figures (continued) Effect of Isotherm Procedure for Heterogeneous Solute Sensitivity of Solute Complexation Model to Kr Sensitivity of Solute Complexation Model to K2 Sensitivity of Solute Complexation Model to K" Model and Experimental Koo Data, Benzo-a-pyrene Benzo-a-pyrene Sorption Isotherm, Model and Experimental Data Model Free and Bound Concentration Ben zo-a-pyrene Model Kdoc, Benzo-a-pyrene Model and Experimental Kdoc, Benzo-a—pyrene Model and Experimental Koc, Benzo-a-pyrene Dialysis of Phenanthrene, l4C Activity on Outside of Bag Dialysis of Phenanthrene, 1“C Activity on Inside of Bag 99 101 102 103 105 106 108 110 111 114 149 150 1/n Csb Csf Cw Cwb er List of Symbols: Freundlich Sorption Intensity Concentration in solid "bound" concentration in the solid "free" concentration in the solid Concentration in water "bound" concentration in the water "free" concentration in the water Dissolved organic carbon Fluorescence in presence of quencher Fluorescence in absence of quencher fraction of organic carbon Hydrophobic Organic Contaminant Freundlich Sorption Capacity "free" compound partitioning coefficient "bound" compound partitioning coefficient Partitioning coefficient to dissolved organic carbon Organic carbon partitioning coefficient octanol water partition coefficient xi PAH [PAHlbmmd [PAHJfrec [PAHIW List of Symbols (continued) Apparent partitioning coefficient Quantum yield of PAH-DOM complex Polycyclic Aromatic Hydrocarbon Total organic carbon DOM Bound PAH in solution Free PAH in solution Total PAH in solution xii Introduction This thesis develops methods for evaluating the partitioning of phenanthrene, fluoranthene, pyrene, and benzo-a-pyrene between solid and aqueous phases. Measurements of the partitioning of polycyclic aromatic hydrocarbons to sediments are made using batch sorption experiments. Additionally, phenanthrene and benzo-a- pyrene partitioning to dissolved organic carbon is measured using fluorescence quenching and reverse phase techniques. The results are evaluated under equilibrium partitioning assumptions and partitioning coefficients are calculated in terms of the solid phase organic carbon and the aqueous phase dissolved organic carbon. Finally, the solute complexation model (Voice 1983) is used to evaluate the data obtained for benzo-a-pyrene partitioning to Lake Michigan Sediments. The objectives are as follows: 1. To measure the partitioning of phenanthrene, fluoranthene, pyrene, and benzo—a-pyrene to Lake Michigan Sediments in laboratory batch sorption studies. 2. To measure the partitioning of phenanthrene and benzo- a-pyrene to dissolved organic carbon from Lake Michigan Sediments using fluorescence quenching and reverse phase techniques. 2 3. To evaluate a correction technique which has been used for the "particle concentration effect" and to apply the Solute Complexation Model (Voice 1983) to benzo-a- pyrene sorption data. Polycyclic Aromatic Hydrocarbons (PAH's) were the chosen compounds to evaluate partitioning to Lake Michigan sediments from offshore Muskegon. PAH's are one class of hydrophobic organic contaminants (HOC's) which are of environmental concern. They are formed from the incomplete oxidation of fossil fuels, and are present as byproducts of the petrochemical industry. Wood treating, oil recycling, and incineration facilities have been the source of PAH contamination for many sites across the US. (Booth and Jacobson 1992). Many of the PAH's are known or suspected carcinogens and mutagens and have been shown to bioaccumulate when exposure occurs in environmental systems (Giesy 1986). Because PAH's are nonpolar and characterized as hydrophobic organic compounds (HOC's, operationally, Log K0W > 103, Voice 1983), they are present in water systems in trace quantities. Sorption dominates PAH fate in sediments and soils. (Karickhoff 1981) developed the following expression to predict K0c values for PAH‘s: Km = 4.9x10‘7 * Kowl-OO Selected solubility data and octanol water partitioning coefficients for a range of PAH compounds are included in Figure l. Figure 1.1 Polycylic Aromatic Hydrocarbon Properties Napthalene Fluorene Phenanthrene Anthracene Pyrene Fluoranthene Chrysene 3—4 benzopyrene age 3 Q Q Q ©8 to Q8 ©© to Go ©© @ © Molggglar Weigh; 128.19 166.23 178.24 178.24 202.26 202.26 228.3 252.32 (1) Handbook of Environmental Data on Organic Chemicals (2) McKay. 1980 Ibili ml! (2) 30 1.9@25C 0.816 @ 21 C 1.29 @ 25 C 0.16@26C 0.265 @ 25 C 0.006 @ 25 C 0.003 Magma) 3.37 4.18 4.46 4.45 4.88 5.22 5.91 6.50 Chapter 1: Theory and Background 1.1 Introduction The fate of chemicals once they are released into the environment is very complex. Many mechanisms exist which describe how a chemical will interact with environment. For hydrophobic organic chemicals (HOC's) which have a distaste for water (or more appropriately, for which water has a distaste) sorption to sediment and soils is a primary fate process. The following chapter is a review of hydrophobic sorption and literature partitioning data from contaminants which undergo hydrophobic sorption. The chapter describes the relationship between observed partitioning and solid concentration and presents the dissolved/particle-bound/dissolved organic carbon bound system for hydrophobic contaminants. Additionally, this chapter presents the solute complexation model as a possible description of the distribution of hydrophobic compounds among the dissolved/particle-bound/dissolved organic carbon bound system. 1.2 Hydrophobic Sorption and Evaluation of Partitioning Data Hydrophobic sorption is a mechanism which is driven by the incompatibility of nonpolar compounds and water (Stumm, 1988). It has been described by some researchers as an entropically driven dissolution reaction (Voice, 1983). Sorption of a hydrophobic 5 contaminant is favorable because of the increase in entropy which occurs when the tetrahedral ordering of water molecules around molecules of the contaminant in solution is broken (Voice, 1983). The bonding force of hydrophobic chemicals is due to amplified van Der Waals interactions as well as the thermodynamic gradient driving the molecules out of solution and on to the sorptive surface (Voice, 1982). Other researchers reason that the mechanism of hydrophobic sorption is really a partitioning process similar to dissolution. In environmental systems, soil organic matter acts as a solvent which is more compatible with the hydrophobic compound than water (Chiou, et. al., 1977, 1983). Partitioning, as it is used in our study, is the distribution of a hydrophobic contaminant among solid and liquid phases. Partitioning relates to solute as well as sorbent properties, and for HOC's, the degree of sorption is related to the compound hydrophobicity in terms of the octanol/water partitioning coefficient (Km) and the fraction of organic carbon (foe) on the sorbent. Total organic carbon content appears to be the major factor in determining a solid’s sorptive potential, while the octanol-water partition coefficient is the best known indicator of the extent to which a compound will sorb (Briggs, 1973; Voice, 1983). Many correlations have been developed to describe HOC partitioning in relation to Kow and foe (Means 1980, Swarzenbach and Westall 1983, Karickoff 1981). Swarzenbach 1983, correlated 6 polycyclic aromatic hydrocarbon (PAH) sorption to several different sorbents using the following expression: Log Kp = a*Log K0W + Log f0c + b Where the coefficients a and b vary for different solute/sorbent systems, f0c denotes sorbent organic carbon fraction, and K0‘” is the octanol/water partitioning coefficient. A sorption isotherm is a way of describing graphically, the distribution of a compound between the aqueous and absorbed phases. A typical experiment would involve spiking varying amounts of a compound into equivalent volumes of water and sorbent. Alternately, the amount of sorbent could be varied and the amount of compound kept constant. After equilibrium is reached, the amount of compound sorbed and the amount of compound in solution is measured. The data is then plotted as amount sorbed vs. amount in solution. Models are used to describe this relationship by fitting the data to mathematical equations. Early studies noted that the absorption isotherm, was linear at solute concentrations less than 50 % of the aqueous solubility. Karickoff (1983), identified that at pollutant concentrations common to aquatic systems, (low ppm or less), the assumption of linearity would be expected. He reasoned that constant aqueous phase activity coefficients would be expected unless pollutant levels approached solubility limits. 7 The simplest isotherm model which describes absorption data is that of linear adsorption or constant partitioning: Cs = Kp * Cw In the linear absorption isotherm, Cs defines the concentration in the soil or sediment, CW defines the concentration in the water, and Kp defines the distribution between the water and sediment. Although linear partitioning may be convenient due to its mathematical simplicity, caution is recommended, since it may not be applicable over large ranges of solute and sorbent concentrations. The Freundlich isotherm is an alternate way to describe sorption data: C = K * C 1’“ S W It is often used for heterogeneous systems such as soils and sediments to describe partitioning data which exhibit an exponential mathematical form (Voice, 1983). The exponential form of the Freundlich equation allows it to be linearized on a logarithmic scale, and therefore it is useful to describe partitioning data from large ranges of solute and sorbent concentrations. K can generally be thought of as sorption capacity, while 1/n is a measure of sorption intensity (Voice and Weber, 1985). 8 In the Freundlich equation, linear partitioning occurs when n=1 and it is often observed for sorption studies involving soils and sediments at low solution concentrations (Karickoff, 1979). Using the logarithmic form of the Freundlich equation, Long=LogK+1/n*Long the Freundlich sorption capacity parameter, K, can be determined by extrapolating the plot of log Cs vs. log Cw to Cw=1 (Log CW = 0). The sorption intensity parameter, lln, can also be determined by the slope of the plot. In order to compare partitioning among different soils and sediments, the observed partition coefficient, Kp’ can be normalized to the fraction of organic carbon, foe: Koc=Kplfoc Lambert (1968) demonstrated that this term normalized the linear partition coefficient for a wide range of soils with different organic carbon contents. 1.3 The Relationship Between Observed Partitioning and Solids Concentration One of the difficulties in the evaluation and prediction of hydrophobic sorption arises as a consequence of the "particle 9 concentration effect". The relationship of solids concentration to observed partitioning in laboratory studies has been well established (Voice 1983, O'Connor and Connolly 1980). It is noted that apparent partitioning coefficients for HOC's which have been normalized to the fraction of organic carbon, foe, decrease with increased solids concentration. The effect is present in data from partitioning experiments which use a varying solids to solution ratio. Partition coefficients have been observed to increase as much as an order of magnitude for every order of magnitude decrease in solids concentration. Voice, 1983, noted that this observation is in conflict with the predictions of many partitioning models and appears to contradict fundamental thermodynamic principles. Although linearized partitioning may be applicable over relatively small ranges of sorbent concentrations in partitioning studies, many researchers have noted that the observed Koo values decrease at high solid concentration for many solute/sorbent systems (O'Connor and Connoly 1980, Voice 1983). This observation is often noted even in apparently linear sorption isotherms. Reasons for this apparent anomaly have been developed by many researchers: 1. Equilibrium has not been achieved, (Karichoff, 1984) 2. Binding to dissolved organic matter has not been corrected for in the calculation of K1) (Gschwend and Wu,l985, Hoke and Giesy, 1992 prepublication) 10 3. The system is not a true two-phase system, rather it includes additional compartments that are not measured independently in the isotherm procedure (Voice, 1985). 4. Competitive sorption between pollutant and an implicit adsorbate initially on the sorbent (Curl and Keoleian, 1984). 5. Presence of both reversible and resistant components (Di Toro, 1986) These developments are the subject of on-going research, and irrefutable descriptions of the relationship between observed partitioning and solids concentration are not available. In actual environmental systems, little data is available to study the affect that increasing foe or the "particle concentration effect" has on observed partitioning. However, a field study conducted by Hoke and Giesy (1992 prepublication) on the Grand Calumet provided a range of sediment foc's and partitioning data for HOC's. The DOC in Hoke's experiments was derived from centrifuging wet sediments sampled from the Grand Calumet and filtering the supernatant. The DOC was defined as pore water within the study. Our reduction of Hoke's data shows that the value of the partitioning coefficient for all of the PAH compounds decreased over the range of sediment f0c which was sampled (Figures 1.1 and 1.2). At the very least, these data suggest that measured Koc values may 11 02 2: S P h u b p h p P u n h n h b h p i b oceecacai .- as... u as. 824a." . 1383 u a . o o o 22E a 33 u g. 83.3.. . 235.“ u a n o o 82228.”. o 3... u g. 03.7% . closed u x m o 0 225328 a 2.3 u as. n85-..“ . 2.338; n a w «2: .93: 2m :20 52. 8.82 I I'I'VVT ' I 1"." V V U r“" U 1 U IVIIVV ' V V I'VVVT I’ 08 m> 00M .m.E 00M firmed 3..ng 32% “08:30 6:80 “NA 65mm op cox 13 not be linearly correlated to sorbent oc%. Other factors are present including sorbent and solute heterogeneities--a conclusion which was hypothesized by Voice 1985. Additionally, further reductions of the data from Hoke's study were completed to evaluate the DOC to f0c ratio. It was hypothesized that the DOC may by a function of foe, since as the organic carbon within the sediment increased, the organic carbon in the dissolved state is expected to increase. As indicated in figure 1.3, DOC shows little relationship to increasing foc. This may be an indication that the dissolution of sediment organic material within the Grand Calumet has reached a limiting value even at low foe. The data reduction from Hoke's study simply indicate the site specific nature of field Koc evaluations regardless of using a coefficient normalized to organic carbon content. Complications include the fact that sediments in the Grand Calumet contain high levels of grease and oil, and composition is specific to sampling location. However, they demonstrate that in environmental systems, Kp adjusted for f0c and corrected for aqueous phase DOM to eliminate the effect of binding to DOM, does not describe fully the partitioning relationship to oc% and DOM. And, although details regarding the exact nature of these relationships are not available as yet, they demonstrate the need for further lab studies. 14 s .8. i . . . 2 a 1 ON a a a a a r on a r ov a r om a mm? .oon ecu >35 Ea: 333‘ . 08 m> UOQ «08:80 usSO "m4 charm 8 'OOO I/Bw 15 1.4 Three Phase Modeling Much of the current research which addresses the distribution of HOC's within environmental systems relies on the concept of a three phase system. Pertinent environmental systems which correspond to a three phase model include partitioning of HOC's from contaminated sediments into the water column (Voice, 1983; Eadie, 1990) and partitioning between sediments and pore water (Hoke and Giesy, 1992). Additionally, the movement of HOC's within contaminated aquifers is described by retardation factors which relate to solid phase sorption and desorption. Organic colloidal material has been shown to facilitate transport by binding with hydrophobic contaminants in experimental soil columns and field studies (McCarthy, 1989; McGee, 1991). The following conceptual schematic shows compartments which may be considered in environmental systems. Actual interactions between each compartment are conceptualized differently by different researchers. It is generally felt that the free fraction of environmental contaminants are significant in that they are bioavailable and can enter the food chain (McCarthy, 1985; Giesy, 1983). 16 Free ‘ . Bound fraction fraction Sediment 1.5 Equilibrium Partitioning By conceptualizing environmental systems as boxes where the distribution of HOC's is defined by partitioning coefficients, exposure and fate analysis can be simplified. Equilibrium partitioning is a concept which has been proposed to estimate biouptake from various compartments in environmental systems (DiToro, 1991) Its success depends on the following assumptions: 1. Equilibrium is achieved 2. Kinetics are rapid in all phases 3. Only "Free" compound is bioavailable The first and second assumptions are related in that rapid kinetics will permit equilibrium to be reached quickly. However, as 17 noted by some researchers (DiToro, 1986; Karickoff, 1983), sorption kinetics can be slow and true equilibrium is not rapidly attained. The third assumption has been tested by many researchers. McCarthy 1985, found that biouptake of PAH's in bluegills was reduced when the PAH's were bound to dissolved humic material. Giesy 1983, found that in some cases the bioavailability was reduced for PAH's bound to humics. Although the assumption of equilibrium partitioning is reasonably achieved under controlled experimental conditions, it is not feasible to suggest that the assumptions are met in environmental systems at all times. None-the-less, partitioning models provide a basis for extrapolating measured data to real systems. 1.6 Solute Complexation Model A model was developed by Voice, 1985, to describe three phase partitioning. The model conceptualizes a phase transfer of HOC binding material from organic solids and a distribution of the aqueous phase between "free" and "bound" constituents. A schematic of the model system is shown in figure 1.4. Concentrations of HOC's within each compartment can be predicted by using equilibrium partitioning. The aqueous HOC species within Voice's model are defined by a partition coefficient between the dissolved organic carbon (DOC) and water. Each constituent in the liquid phase is in turn distributed to the solid phase by distinct partition coefficients, K1 and K2. The 118 .2822 83303800 820m mo ozaaonom 6A oSmE mm—u—ucag a mm< n such vcaoaeou a .IIIIIIII-..I..1 EOE _ venom _ ~x \\ _ \\ cczoasou x umagom x u.=mmco=. u_=omgo pg Fl ucaoaeau Luau: omen umfia 2.5m mmfia 2.5: 19 overall partition coefficient or apparent Kp determined experimentally is then defined as: Kp= (Csf + Csb)/(er + Cwb) Where, Csf = mass fraction of free compound in solid Csb = mass fraction of bound compound in solid er = mass fraction of free compound in solution Cwb = mass fraction of bound compound in solution Although Voice did not propose a distinction between Csf and Csb, we have developed it in this way since K1 and K2 are equilibrium coefficients. Voice proposed that the observed decrease in the partitioning coefficient with changes in solids concentration be attributed to transfer of a sorbing, or solute binding material from the solid to the liquid phases. The amount of (the binding material released to solution would increase with increasing solids, resulting in values of Koc which decrease as a logarithmic function of solids concentration. In order to evaluate the amount of a contaminant at equilibrium within each phase, the solid phase partitioning coefficient as well as the free/bound distribution within the aqueous phase must be measured. The solute complexation approach also incorporates solute heterogeneity in its development by allowing for different equilibrium sorption coefficients for the "bound" and "free" phase in solution. Figure 1.5, adapted from Voice, shows a hypothetical chart 24 587821 111102 SOLID PHRSE CONCENTRRTION (NC/G) l J ALL 1 r r L P 20 -—— Constant Initial Concentration Constant Solids Concentration S81 C =100 x1= to“ 5‘10 = 2 - 2 K2 1° coeso “0 on C I 01 _‘ I — - 1.0 C / oz / 3': .4 p1 ”'1 m v-1 "1 '"1 3" a P1 O ID ‘ 0 «I 5 5159709 2 3456789 1:101 mo? 1 SOLUTION PHRSE CONCENTRRTION (NB/L) Figure 1.5: Effect of Isotherm Procedure for Heterogeneous Solute 21 indicating the effect of the isotherm procedure on observed partitioning for a heterogeneous solute. The curves represent a system with two compounds having partition coefficients of 104 and 102. Each initially comprises 50 % of the mixture. The curves are developed assuming both the constant and varying solids experimental techniques. As can be seen, the varying procedures result in different isotherms. The constant sediment isotherm is linear while the constant concentration isotherm is non-linear even on the log-log plot. Voice (1983), experimented with humic and fulvic acid sorption to activated carbon and showed data trends similar to the hypothesized heterogeneous solute curves. He interpreted the results as examples of heterogeneous solute sorption. Several researchers have experimented with systems consisting of an inorganic surfaces coated with humic and fulvic acids to simulate natural organic coated aquifer material (Murphy, 1990; Slautman, 1992). Slautman found that the PAH binding properties of humic and fulvic acids were reduced when the organic material itself was bound to a synthetic solid. Koc values for anthracene which were obtained by Murphy, decreased with increasing foc for both peat humic acid and Suwannee humic acid. The sorption enhancement due to coated humics was not linear and the anthracene sorption was most dramatically increased for low foc's. Murphy attributed his results to heterogeneities in the sorbent phase due. to alternate configurations of the humics or size exclusion in sites available for HOC's with increasing foe. The possibility of phase transfer or solute heterogeneities, however, was not considered. 22 The models developed by Voice and the abundance of data showing a decrease in K0c with increasing sorbent in terms of both foe and solids concentration, suggest that solute complexation is a plausible explanation of observed and natural conditions. This is not to say that sorbent heterogeneities do not play a role in sorption phenomena, however, the decreases in Koc with increasing foc or solids concentration observed in our study and seen in several published experiments is not described adequately by sorbent conditions alone. 23 Chapter II: PAH sorption Experiments 2.1 Introduction The objective of the following chapter is to measure PAH sorption to Lake Michigan Sediments in laboratory batch partitioning experiments. The degree of sorption is described as a partitioning coefficienth defined as follows: Where C8 is the concentration of the PAH in the sediment and CW is the concentration of the PAH in water. Lambert (1966, 1967, 1968) and Karickoff (1983) found that the observed partition coefficient Kp remained essentially constant over a wide variety of soils and sediments when it was normalized to the percent organic carbon. The partition coefficient is normalized to the organic carbon content of the sediment by dividing Kp by % organic carbon. The organic carbon partition coefficient is then defined as: Koc = Cs/(CW * %TOC) Batch isotherm experiments have the advantage of being relatively simple to study PAH sorption over a range of compound concentrations and sediment concentrations. Within this thesis, PAH partitioning over a range of sediment concentrations from 500 to 24 40,000 mg/l and PAH concentrations at ng/l levels is measured in batch experiments. The solid to water ratio has been shown to play an important role in the evaluation of partition coefficients. The absorption isotherm can be obtained by two experimental methods. The first involves keeping the solid to solution ratio constant and varying the initial amount of solute, while the second involves varying the solid to solution ratio and keeping the initial solute concentration constant. The effect of this change in experimental technique on Koc is evaluated in this Chapter for phenanthrene and benzo-a-pyrene. Absorption data is modeled by plotting an isotherm. The isotherm is a graph of the solution equilibrium concentration vs. the solid phase equilibrium concentration. Many models are available for fitting absorption data, however, the Freundlich model can be used for large ranges of solid and solution concentrations and for this reason it is used to model the PAH sorption data found in our study. The Freundlich Equation is defined as follows: Cs = chwl’n Where, Cs is the equilibrium solid phase concentration Cw is the equilibrium solution phase concentration K and 1/n are fitting constants 25 The following objectives will be met in this chapter: To develop an experimental procedure for PAH batch sorption studies. To establish the relationship between solids concentration and the partitioning of phenanthrene, fluoranthrene, pyrene, and benzo-a-pyrene. To determine whether correcting the apparent water concentration for the amount of PAH bound to aqueous organic matter as total organic carbon is adequate to eliminate the dependence that partitioning has on solids concentration. To establish any differences in using a constant and varying sediment batch sorption technique for phenanthrene and benzo-a-pyrene. 26 2.2 Materials and Methods 2.2.1 Sediment Sampling Sediment samples were obtained on May 30, 1991 from four locations offshore Lake Michigan at Muskegon harbor. NOAA (National Oceanic and Atmospheric Administration) provided transport and equipment for the sampling trip. A Ponar sampler was lowered at each location shown on attached figure 2.1 and a grab sample was collected. The top 1 inch layer of the sediment sample exhibiting dark, organic color was retained for laboratory experiments. The sediment samples were processed by sifting wet through a 200 mesh screen. They were subsequently centrifuged at 5000 rpm for 1 hour to remove residual water and freeze dried at - 40 ° C for 12 hours. The dry material was pulverized in a mortar and stored at room temperature for experimentation. An evaluation of the organic carbon content was completed by the Standard Methods, 1990, solids determination. Additional samples were tested for TOC by the Michigan State University Crop and Soil Science laboratory. Because of the turbulence at the entrance of Muskegon Harbor, most of the silty organic material was scoured at the shallower sampling points. This was evident by the organic carbon percentages as well as visually within each sample. Testing of PAH binding was only conducted on the samples collected at 100 and 75 meter depths, 27 mg ‘m. m a S Figure 2.1 ’40 1 r :\_ :imn 3m .:.\ 3: 28 since they had the highest organic carbon fractions and therefore would exhibit the greatest binding effects for PAH's. The organic carbon content of the samples along with the station location is as follows: WM Station motion “at“ long,) % organio Q 100 43°-13.89', 86°-13.23' 5.6 70 43°-l4.11', 86°-30.56' 4.8 2.2.2 Batch Sorption Experiments A flow diagram of the procedure which was used is shown in Figure 2.2. Initially, Corex brand #4664, 25 ml centrifuge tubes were spiked with radiolabelled PAH standards prepared in acetonitrile. The radiolabelled PAH's obtained from Sigma chemical were purified by using reversed-phase high pressure liquid chromatography (HPLC). An example of the fraction chromatogram is shown in figure 2.3. The instrument specifications which were used for this procedure are included in Appendix 11. Only the fraction corresponding to the peak at 9 minutes was retained for experimentation. Selected information regarding the 14C labelled PAH's is included as Table 2.1. After the carrier solvent was permitted to evaporate under a fume hood, about 25 g of purified water (deionized, carbon filtered, reverse osmosis) with 0.02% NaN3 as an antibacterial agent was added to each tube. Known quantities of the freeze-dried sediments Figure 2.2: Procedure Flow Chart 25 ml Aqueous Sample/ Sediment Slurry Centrifuge at 12,000 RCF, 10000 RPM Supernatant Sediment Count 5 ml of Rinse through " Aqueous 0.45 um millipore filter l :mpor e titration Dissolve filter in everse 359 10 ml of LSC Cocktail Techm ue , I ' Count Count Fultrate Count Extract Sample p. Fluorescence Quenching Finally, rinse tube with 20% MeOH, 80% MeClZ Two washes 5 ml Count entire rinse H Absorbance at 255 29 30 Figure 2.3: Radiolabelled Compound Purification Integration time 15.00 min Peak width 1.30 min Peak sensitivity 2.0% Minimum area 3000 ----Area percent report---- RT Area Area% Peak Name 7.764 3053 0.058 9.908 5066905 96.935 11.173 65093 1.245 12.584 6367 0.122 13.355 85716 1.640 9 Peaks integrated 100-33 3— m .6 3", 3. t : f l ‘l 3; 3‘ E l 80-1 t : * a“- E :- g . é i :' . l . l i w l 1 1 g I ' l e 1 l 1 ' ' r i i .. : 40—1 . 1 i : i i ' ' r 1 :3 , ll: 1 ' i it I i ' I: 1 20—1 " . ' l 5 2' ' l3 4 5 f; i i I l: i i 1 {I a, l ' t 4 \ O—{L ----------------- J -:M.W& .5“ " fi fi * I ' T v 1 vvvvvvvvv Tia ' 2.00 4 00 6100 8 00 10.00 ——Ana1ysis Channel A, 50.1 mVFS ——Qverlay Channel A, Min u-Overlay Channel B, Min 0.0 Max 31 Table 2.1: Radiolabelled PAH Data Phen Flrntn Pyrene BAP Product # 31,528-1 F6147 P4185 B9776 Lot # O49F9271 O61H0151 O61H0152 O8OH9216 Molecular Weight. 178.2 202.3 202.2 . 252.3 Purity" >98% 98% 98% >98% Activity, mCi/mmol 13.1 S S S S 16.2 Concentration, mCi/ ml --- 1 0.5 6 1 Solvent --- Benzene Benzene Toluene * determined by radiochromatography 32 were added to each centrifuge tube. The tubes were then covered with opaque adapters and permitted to equilibrate for 24 hours on a wrist action shaker to allow dissolution and absorption equilibration of the PAH spike with the sediment. A kinetic experiment was initially conducted using pyrene as a model compound. Pyrene was chosen because it has an intermediate hydrophobicity in the range of compounds which we studied. A series of batch systems spiked with pyrene were permitted to equilibrate over increments of one hour. After this time the same procedure was followed as previously described. The majority of the pyrene, approximately 90 %, was absorbed in 2 to 4 hours, reaching an apparent equilibrium over an extended period (Figure 2.4). Voice (1983) found in his experiments that an equilibration time of 4 to 6 hours was necessary. Karickoff (1980), hypothesized that sorption kinetics were described by a short and long term coefficient, the latter limited by diffusion into the soil matrix. For the purposes of this study, equilibrium was operationally defined at 24 hours. Each tube provided a point for the absorption isotherms at varying sediment concentrations and constant initial spike for the varying solids isotherms. A range of sediment concentrations from about 500 mg/l to 40,000 mg/l was studied. For the constant solids isotherm procedure, equal amounts of sediments were used in each tube and the concentration of PAH was varied. After the 24-hour equilibration time, the tubes were centrifuged at 12,000 RCF, (10,000 RPM) for 2 hours to separate solid and liquid phases. Five grams of 33 or mono: o N30 1. ms. 303.2280 7 + fleet.— » A 0300.0 1 m+moo.m 1 m+oooé 9mm ozong occur“ 3am ounwwm widen; 11 undo 34 the supernatant was drawn off the top of each tube and counted with 10 ml of LSC cocktail for 10 minutes. Three counts were taken for each sample and average values are reported. The instrument specifications which were used for this experiment are included in Appendix II. The remainder of the supernatant in the phenanthrene and benzo-a-pyrene experiments was used for reverse phase separation and fluorescence quenching procedures. These techniques were described in detail in Chapter 111. After separating the supernatant, the residual solids in each tube were flushed with DI water through Millipore 0.45 um filters. The filters with retained solids were then dissolved in 10 ml of LSC cocktail. The vials were shaken vigorously- -2 to 3 minutes and allowed to set for 12 hours. Subsequently, each vial was analyzed on the Beckman LSC counter for 10 minutes to determine 14C activity. The centrifuge tubes were then rinsed with 10 m1 of MeCL2 (in two 5 ml washes) to remove glass sorbed PAH. The entire rinse was combined with 5 ml of cocktail and counted for 10 minutes. Tables 2.2 through 2.6 show the data which was generated using the batch isotherm procedure. The tables are spreadsheets of the calculation of solid concentration, PAH water concentration, and PAH concentration. Additionally, the PAH sediment concentration is adjusted based on the recovery efficiency. This calculation is possible in the procedure since the total initial activity of the spike is known and the glassware sorbed concentration, water concentration 35 voévm.~ 5&3... 8+3 2 2.2 cc... 8.936 :8: 8.0 3600; moécod ~06. 2.0 000003 2522” no.3 33.0 S .v.0+~$.~ v0+w-.~ moémod mode 2: mew—m... 32$ 0 8&8.» mo+m~mé roan t~d 000000— 36va 9.3 39.0 o— vo+wm~.~ voévonu. 8.056 0...; 3m moéond .38: 3:... 8635 voamofi~ «N... de 0808— «9.3... 0.3 $16 m 5&me voévvd 070:." 3.: Camp 07mg... 3me 3.... v0.62”.— ooémmd .05 80.0 000000. mo.~ov. 9:3 38.0 a v0+u-.m v0+wm0.m 0.33.06 vfima . 0mg— 0—4wmw.~ vmmmwv . ~06 0.0.600... v0+mm~d mmi nmod 000000— mQSn Vndw n 8.0 s v0+w~m.n eooumnd 0708: 3.3 0v: opownNd 333 3.0 3&3..." moémm; ~06 «3.0 000000— 563 3.3 n80 m voawond. coJ—md 073m; ~53 ~02. 0735., 883.. 5.0 «.0103; voéood -.n 03.0 000002 3:33 3.2 3.8.0 n eo$mfi~ «Oeuvofl 0:80; 360 mm: 073v... anONZ. wad voownvé c0+m$§ 2d ~20 000000— 0~.~nm~ v.n~ .200 v voémmd eoénnfl 3&an 03 was 0703., 8309 3.0 «0.30.» .5236 3.... I ”.0 00000: 3.290. 3.3 38.0 n v0+wmw.~ ¢0¢mo~.~ opommm; Mada vmnp 073m..." mwmmmo w moownwm v0+wofiv mod n50 00000».— vm.~vm~ 26w 28.0 N ¢o.un~.~ eoémwfi 2&3.— Avdm ~nop 8.0mm; wnmmns no.0 3+0an coévod 36 2.0 00008— :.33 ~12 08.0 .. 58 885m 9. 9.28 038:. x 88.3. 3&8 :8 3...: .5 52.5 ._e n 18...: n 8. a. a RN e «2 68 exam :9: dam a 6:; a 58563 n 295m 2253.0 633? uou acoEfivm 35.8 2262.0 355.com 320663 3323 «.6023, \; uox 033:: .523: .o 308.com 8mm mew—£5.80 ueouficmoonm ”NM 3an 36 8.8.3 8.8.2 858.“ :8 8.8 8.83.5 «.39 8... 8.80.. .2 8.... 290 82 .2 1.2 38.8 N. 8.88.. 8.88.. 8.: .6 8.2 v S. 888.. 82 .n 8.... 8.8.... 2 8.... 28 82 822 «.2 88.8 2 88:2 8.23 “amass 2.; 8.2 8.88." 2.82 n 8.82 2 8.“ 28 82 .82 2.2 88.8 o. T8.8.; 8.2; 8.28... 2.: 3.2 8.2: 8.22 8.... 8.8:... 2 8.“ 82.8 82 .8: 2.2 53.8 a 883.... 8.2...“ 8.83.. 8.8 02. 882.. 2.8.: 8... 8.22 2 8.... 2.8 82 88: 3.2 82.8 a 8.2.2 8.8.... 8.83 2.8 2.1 8.3.2 8.82. n 8.82.» 8 8.“ 88 82 w .8 8.2 2.. 8 . 8.22.. 8.2; 8.82 2.8 2.: 8.82.” 8 32. 8.“ 8.8.... 9. 8. 2.8 82 82v 8 ..2 2 . ..o w 9.8.... 8.8.... 8.88.“ 2.2 8.2 8.8: 2.8: 82 8...: E 2 .2 88.8 82 22 8.2 28.8 n 3.82.. 8.82.. 8.82.. 8. z. 8.2 8.23 282. 8+ 8.8.... 2 Ba 88 82 22 2.2 888 v 8.83 8.... 2 8.82 9.8 8.2 8.2....~ 8. .2. 8... 8.82.. 8 8.“ 28.8 82 83 2.2 8.8.8 m 8.8.... 8.82.. 8.88... 2.2 2.8 8.885 2.8: 8.. 8.81... .2 2 w 8.8 82 88 2.2 :88 ~ .22... .829. .929. .929. ~82 .929 N2 2.. 8.88.. o: 8... 88.8 82 o 2.2 o . $8 8.3.8. 3. 952.8 8.68.. t 8.8.8 95.8 Elmo .56qu ~09: .5 5.8 ..E n 2%.? m on. a. a n2 a «.2 58 .33 8E .63 a .85.. a 5868” a 295m Ohnamna. UUUOF< UOu “EOE—bum cues—am Ountnnfiv ”COP—tbom n803( $803(: 3 8V. 8.3.9.. .25.... .o 8.2828. San— mfiooEfium oaofiafiosfi and 053. 37 8.52.. .829. .829. 2.8 8.82 53.8.. 8. 8. 2.28.3 82 2... .88 882 88 $2 8 2. 8.228 8.8:... 8.82.... 2.2 8.2 8.88... 2." 8. 828.82 8.: :8 '28 882 8822 2.2 2&8 ._. . “8.2 ... 8mm ... 8.82.... 2.2 ~88. 8.82 :8 o. 8me8; 1.: 8.... v2.8 888 1.8%. .22 88.8 o. 3&3... 3.8:. 893 . ...v 88. 8.88.2 .8. 8. $8.36. 1.8 .3 .828 882 5.2.8.2 8.2 :28 a 83.8.. .352. 852.. 3.2 8.888 8. m .38. .. .8 .3. 2.8 882 $288. 3.2 J82~8 8 54.8.... 8.88.. 8.8... 8.... 2.2 888... 83 8. ~ .8323. 3.: 8.» 2.8 882 83.2. 2.2 88.8 2 Iain... .282. .55.: 88.. 8.888 8. 28.8.8 8. 2.... m . .8 882 8.88.8 2.2 I... .8 o flwflmfimj 8.82.2 8.832 8.8 82...” 8.8.... 82 8. 88.8. 2 8.. 2.... 882 85m? 3.2 888 n 3&8... 8.8m . 8.2..” 888 2.: 8.8.82 ~88 8. 28.2.3 82 83 '88 882 8.8.2 .Inwmm 38 v 3.52... ..w8...wm..t. -8338 :8 21.82 8.88.. 28 8. 82.8.1 .3 z.“ 88 882 8.8... 8M2 .588 .m L Wm.w....m-. 3.8.3... EVER? 2.8 8.88. 8.82.8 28. 8. 8 5.2.28. :2 on 288 882 882. .82 .88 2 3mm... .38... 8.82.. 8.2 8.82 8.8.... 88 8. 82.828. .38. I .88 882 2 22 8.2 a... .88 . 58 8.88.8 9. 93.8 82,8... : 8.898 8.38 :8 .8683 ~92 .5 <28 .m: n 2.8 ._E n 3. a. 8 n2 0 8.. E8 .33.. :9: .88 a 6:; a .8662. . 2853 3.3.8.5? “832...: co. “coflbwm 3:23 2:52.? 35:53 :38 .E 03 500i: 2626< I1 I. 1.8» II 832.80 .33.:— .o 8:828 88n— msEoEtmm 2.85m Jam onH 38 .923 .929. 5.; 8.83 5.53 5an ”8: an 5.33 co.“ 3: 5&2.” 8.o 8.2 o : flmqwm : 83 $2. 8&2; 3.3 8.3 _.~ 8&3.“ 8.33 :3 3.“ 8&8.“ 8.... 3.8 5.32 3.82... 02 9x3 2 wmmmwm SJ 3133, 89.3 2.3 8.33 8&3.» 853 2.3 2 8.33 8.“ N .2 5&2.” 2.32m 3:2. 23 a $3302 3232: 8.: 2 3.3 8.33 8J2.» 8.33 38 N.“ 8.32 8.“ 8.3 6%.; ogwfi 2.2 2.3 o wmmwflvm: 83 88. 8.83.. 3.3 No.23 8.56 Sam: 2:. I 8.32 n 3.8 6.55 8.8an 2 33o N wmflflmmmlflmwmn: 8.3: 2.8 8.33 8.: 2 £38.. ~32 a.“ 8.8: 86 2.3 :32.” .33: 3.2 $2.0 m Ammmfi : 3.850% 8&8.— 83 8&8.“ 3.3... 8.3 3 3 . ~— 85 3%: 86 2.8 5&2." 3.32 5.2 83o n “madman. 3.392 Samoa ~23 .oéfld 8.32 8.33 82: 3.. 8.33 8..., 8.; :32.“ ~33: 3.2 81o . 332?: $1238.” 852.. 8.8 6.3M... .98: 8J2.— .t: awn coax; 8.“ 3.5 :32." 3.32 2.2 826 m n :2. .82 2.30:2 8.3: 8.3 8.3: 6&2; 8.33 v z: 2 5.33 2.. n :3 6%: 3.8” 2.2 28.0 ~ 3.8%? @3832 8.33 8.: 6.33 :35.— ooéz." 2 P : 2.... 6.2 I n 3.3 6&2.” 2.3% 8.2 806 . :8 8:88 9. ago .988”. : c888 83.8 com 9528 23 “Semi 3...: .5 <68 .383< 228... .5 .e n .68 E0 3.} 35 d3. m .25 m .2253 a {as Illwumflwmo 933...; won. «SE58 35.3. 22.636 22.636 u§3<7 -1 Elmo: 3:33 3.332. 53 83903. 2.38.9253 San— wafiofitmm unobaééncom 6N £an 39 8.08... 83.8.. 8.2 8.8....” 8.88 8.8... 8.88... a... .2 890 0000.... 8.8.8 0.8 808.0 0. 8N8.” 8.08.. 8.: 888.. 8.8....“ 8.8.8 8.83 88 .N... 88.0 0088 82.888 8.8 8.8.0 o. 8.88... 8.88...” 8.8 88.8.. 888.. 88.0.. 8.8... .8 8.... ~30 0008. 8:188 28 83.0 2 wnflwww. 8.1%.... 8.: 8.88.. 888.” 8.8.. 8.88. 0.: .3 8.8 0088 3.088 2.8 89.0 m. 8.8... 8.8.} 8.8 8.8.8 8.83 8.82 888.0 2... n 02.0 0088 2.2.80. 88 8.0.0 8. 8.8... 8.8.8 3.8 8.888 8.83 8.88 8.80.8 :8 I... 88.0 0008... 808.8: 8.8 80.8 1 $8.88.. 8.88 8.8 8.8... 888.. 8...... 8.83 22 8.... 88 00008 888.8 8.8 8.6.0 m. 888.. 8.88.. 8.8 8.8... 8.8... 8.8... 8.88.. 8.. 8.8 8..0 0088. 88Mm8... .08 80.0 N. 8.80.8 8.8.8 8.8 8.0.8 8.8.8 8......“ 8.08... 83 8.... 8.6 0000.... 88088 8.8 28.0 .. 88...... 8.8.08 88 8.8..” 8.02.. 888... 8.8.... .0: 8.8 2.0 0088 8888... 8.8 28.0 0. 3.8m... 8.8.... 8.: 888.. 8.8... 8.88.. 8.88... 88 2.... ....0 00008 88800. ~08 88.0 m .mflwmflwul.mmm2.. 88 8.08.. 8.8... 8888 8.8.... 28 88 2.0 008: 280.28 8.8 . 88.0 0 wmmquw.‘ 8.80.. 88 8.8.... 888.. 8.808 888.8. .8. n.» 3.6 0088 8888 8.8 .80 8 8.8.... 8.8.... 88 8.88... 8.8... 8.80.. 8.8... 08 8.... 8.0 0088. 88.800. .8 8.8.0 0 8.82 8.088 8.8 8.8... 8.8... 8.“... 888... En 8 8.0 0008. 88.888 8.8 88.0 8 3mm: ..0mnwa.c.v 88 8.83 8.83 8.8... 8.80.. '8 8.... 88.0 0088. $8.88. 2.8 $8.0 c 8.8... 8.88 8.8 8.83 8.88... 8...... 8.8.... 80. 8.8 .0..0 0008. 888.82 1.8 82.0 n 888. 8.88.. 8.8 8.83 8.8.... 8.80.. 8.8.08 :0. .0.“ .80 0088. 808.88 8.8 88.0 N 8.8.8 8.8.5 8.8 8.38.. 8.88 8.8.0.. 8.808 88 N“ 8.0 0088. 888.8... M8 .80 . 58 8.398. 0S8 968.3. 8098 95.8 28 28...: 0n 5:. 8~o£< 58.3.3 .8... .03 0.9.2. 3858 3.9.8 82380 80668 3.53 0.2.68.0 35660..” 35663 5026.. 30021 i 8x 038.3. 32.2. 80288 80 3&0 Sam 9.80...th onubfiééaSm 6.N 055. 40 and sediment concentration are measured. If these three measured quantities did not equal the total initial spike, the sediment concentration was increased correspondingly. The material balance recovery then indicates the sediment extraction procedure. Appendix 4 includes a key to tables 2.2 through 2.6 which explains how the column calculations were made. 2.3 Results and Discussion: Solid Phase Sorption In some cases, the aqueous phase measurement of PAH was close to background levels. In order to test whether the data was significantly above background, an hypothesis test was completed under the following assumptions: 1. Ho: u< or = O 2. Ha: u>O 3. Test Statistic: Student t, t = (x-u)/(s/sqrt n) 4. Alpha = 0.05 5. Critical value @ n=3, 2 degrees of freedom 6. Reject H0 if computed D or = 2.92 Based on this test, only one data point was not significantly greater than a background of O dpm. The results are included in Table 2.7. The data on background counts is included in Appendix five. Since the data points were background corrected, the hypothesis test compared the data to zero. 41 mo» mmmmmmm.mm mmmd w fimvp 8» Nvmmwpomd mmm.w 3.3 mm; . mvvvnwndp van 5 fimm mo> mm 533..» mud moKN mm» m mevmmmK mmmd mmdm 3; mownowmdp wmd MNmm mo> wPOmonowN m9}. wnfim mo> Nvtmmwdp mmvd mo. 3.. 3» Vmemdem mmé omém mo> m — 8 {CNN mmwé m finw mm; mmNNNdeN muné 3.6m oz $9.055. mmmdp 3.9 News .39 A: taflmiivu» so .5 555% .3322 353:8 A3mm 352933 26% main yo: .8 355 $335 05 was >05 8 “$25. 05 225 mcgunzzoucou .3“; 555% 0:23.909“? .5. mozmzaum mucoEoSmmoE bES< ocoiaééusom E ooqoumcoo KN £an 42 Figure 2.5 is an example of the K0c values which were obtained for the varying sediment isotherm procedure. As shown, the K0c value for fluoranthene exhibited a logarithmic decrease with increasing sediment concentrations. The results observed are similar to the work completed by Voice (1983) for several solutes using Lake Michigan sediment as the binding phase. Generally, a one order decrease in the partitioning coefficient is observed with a two order increase in solids concentration. Voice, 1983, noted that at very high solids concentrations, the Koc appears to reach a limiting value. This is not apparent in the range of concentrations that were used in this study. Use of the Freundlich isotherm model, although appropriate for fitting the PAH sorption data, would not be appropriate for identifying a limiting Koc value because of the exponential form of the equation. For the procedure which we used, it was necessary to identify solid phase recoveries and correct the data for extraction inefficiencies. Figure 2.6 is an example of the recovery which was obtained for fluoranthene. It is a plot of the material balance % recovery vs. sediment concentration. The values also appear in table 2.3. Generally, the recoveries decreased with increasing solids in the system. Karickhoff (1980), observed that the ease of extraction of the sorbed phase was dependent on the equilibration time. Longer equilibration times resulted in reduced recoveries. These observations led to the conclusion that sorption continued over time from the surface of the soil into the soil matrix. It is suspected in our study that decreasing extraction efficiency related to the increase in 43 :9: 6038:3050 Eons—vow oooov oooom oooom oooop o p ’ D L «65 u «E 883$ . 3833 u > ... ooooow a at 888 W. 3 I 000000 ocoficmeosfi ”coumbzoocoo EoEEum m.» 8M "Wm oSmE r ooooov 4'4 oooov =9: 633.888 Eoéuom oooom OOOON - . oooow «8.0 a at 3-383 - 83¢ a .2 anmnom Bob among—852m mo bosoom 6N 0.5mm cow Meltooou as 45 organic material which was available to bind the pollutants more fighdy. As noted, the observed dependency of Koc on the solids concentration may be the result of binding to solution phase DOM. Several researchers have suggested the use of a corrected apparent K0c which can be determined from calculations similar to the following equation (Hoke and Giesy 1992, Gschwend and Wu 1985): Corrected Koc = Cs/(Cw - K doc*Cw*DOC) Where K doc = partitioning coefficient to DOC DOC = Dissolved Organic Carbon The intent of the correction is to make a distinction between the "free" and "bound" forms of the HOC. The measurement of Cw does not make this distinction. The measured value is the total HOC in the water. By assuming that Kdoc= Koc, the value of the "bound" contaminant in solution can be estimated and subtracted from the measure total to obtain "free" HOC. In order to assess this correction for use with our data, we applied it to the apparent partitioning data for fluoranthene. Kdoc was assumed to equal K0c which is defined as a function of K0W from the approximation (Lake 1990): Loglo K0c = 0.00028 + O.983*Log10 K0c 46 As shown in Figure 2.7, the K0c values are increased as expected due to the correction which was applied to the measured aqueous phase concentration. However, the decrease in Koc which is observed over the range of solid concentrations is still present in the corrected values. The correction equations which were implemented by Hoke (1992) do not correct for the solid concentration effect which was observed in this study. Figure 2.8 shows varying solid partitioning coefficients for all of the PAH compounds which were used in Our study. As indicated in the figure, the decrease in apparent K0c with increasing solid concentration is observed for each .PAH compound. Generally, the effect is the greatest for the compounds of higher hydrophobicity. This is apparent in the slope determined by logarithmic regression for each series of data. It increases (negatively) for the more hydrophobic compounds. Considering the hypothesis suggested by Voice (1983), these results are expected since DOC binding would be the greatest for increasing hydrophobicity. In our data set, benzo-a-pyrene, as expected, exhibited the greatest decrease in Koc over the experimental range of solid concentrations. Voice (1983) conceptualized a solute complexation model to describe these observations. The model relied on two major occurrences: 1. Phase' transfer of solute complexing material (DOC) from solids to the aqueous phase. 47 .35 60.32850 E0663 ooooo F coco? ooo _. 00—. DP P b b L I r .bh I b b b b b hLD I b b h L b OOOOP mad u «E 383i . $383 a > . I I I 00000.. X .0 0 890 u «(a mmmvmdax . $283 a .2 cozootoo .200? 9. e umSmmoE ax a Sam aoquw oqoficmeoafi also. 8&3 oooooo. 48 ooooow P P 0000—. bib.- =us €2.63 ooo F oo _. P b b .r. D b b b t. I ocmEEmcmzm 22:582.... 82?. ocoiafiégom Oi. owed u «E gnu—5i . fiommmmd u a. O [la/It ~55 n «(a 883....“ . 2883 n > Sad u NE 5 auto-.." . $88: a > 2.3 a 9m 5.26-2. . 96.33 a > 235% 59:22 3.3 "V‘ £8 8:98 IE "we 2&5 how dx ‘30; .to; potsnlpv 6x11 49 2. Heterogeneous solute in the aqueous phase made up of "free" and "DOC-bound" constituents. Under these hypotheses, a sorption isotherm resulting from constant and varying solids techniques would produce a graph similar to the hypothetical plot shown in Figure 2.9. Data shoWing the absorption of humic and fulvic acids (Voice 1983) on activated carbon indicated behavior similar to that shown in Figure 2.9. It was suggested that these results are examples of heterogeneous solute absorption where the analytical technique does not distinguish between the various components in solution. In order to assess the suggestion of heterogeneous solute sorption, varying and constant sediment isotherms were constructed for phenanthrene and benzo-a-pyrene to model both relatively low and high hydrophobicity compounds. The Freundlich isotherm was used to model the data. Figure 2.10 shows the results obtained using phenanthrene. As indicated, separate logarithmic regressions on the constant and varying solids data did yield different slopes, however mfi SOLID PHRSE CONCENTRRTION (NC/G) 50 p u- ;---Constant Initial Concentration Constant Solids Concentration - S=1 C 400 A4 0 5=10 P K]: 1U P - 2 - 2 C l = 1.0 I c I 02 I I I I s=103 4 1::::HJ 2 1 2 a 4 55739] I!” h ' SOLUTION PHRSE CONCENTRRTION (NC/L) Figure 2.9: Effect of Isotherm Procedure on Observed Partitioning for a Heterogeneous Solute 51 55.0 60.5.8 S o. a 9 h h b D h P I - I P P P D b D t. mn=om Emumcoo < 93.0 0 NE mmem. Fx . oomommd u > I flaw 35> D 52. u «(a 8899; . 383.» u x r D t <\ . a u . s a ‘ V D 1 1 «2.8 33:; new 2228 . Ecofiomfi cesarean/w ocouficmaonm ”SN 8me how oo— ‘tuowtpos fix/wan 52 the difference in the results was not as evident as the difference observed using benzo-a-pyrene. For phenanthrene which is less hydrophobic than benzo-a-pyrene, the data may suggest that little binding occurred in the solution phase, thus there is little difference in the constant and varying sediment concentration isotherms. Figure 2.11 shows the results obtained using benzo-a-pyrene. As indicated, the isotherms obtained using the constant and varying solid techniques were strikingly different. The BAP experiment incorporated three constant solids isotherms including 4,000, 10,000, and 20,000 mg/l solids concentrations and two varying solids isotherms in which different initial concentrations were spiked. The constant solids isotherms are parallel on a C; vs CW plot. Additionally, the Freundlich sorption intensity coefficient for constant solid data is less than 1. Logarithmic regressions on the varying solids isotherms, however result in Freundlich intensity constants greater than 1, consistent with Voice's (1983) results. The general form of the data shown in Figure 2.11 is consistent with results obtained for humic and fulvic acid sorption to organic carbon using the varying sorbent and varying initial concentration techniques (Voice, 1983). Simple linear partitioning would have modeled the data as a straight line and the slope would be used to predict the partition coefficient. However, as noted by Voice and paralleled in this study, our results suggest that a full description of the data requires at least one additional variable, C0 or S, to describe equilibrium conditions. Additionally, extrapolation of data from 53 3.2.3 300:... 2. Sin 8282 288. 82: 82 h b r b n n b b h P b b b b b n b b L b h b b p b OP \ n a 2:. u g. 28.9... _. #382 u .2 2M S poo .0 O E . .. 88 u «é ”82.9.." ._ 1038; u 2 < 8o cm. 4 28 n «E 855% .. 36885 n 2 BE 08.4 U . 88 u g. 38.9... . 1038." u 2 .35 8m. 3 O . 88 u g. Rang ._ .128... u 2 pan on .50 + n .1 m 2 4 1 1 n o .l w OF 4 0 O . O I O I . . Id “ "3:058. EoEBow a5>3> new 2.2200 ” 8559A 52903.2 onobaééunom fifim oSmE opow 5l/fld0 and Pll°3 ul 54 experimental to field conditions without designating experimental design conditions is questionable. 2.4 Conclusions: PAH Sorption Experiments The relationship between solid concentration and Koc is evident in figures 2.5 and 2.8. As the concentration of solids in the system increases, the partitioning coefficient Koc decreases exponentially. For the range of PAH's studied, the effect is increased for the more hydrophobic compounds. The following summary identifies the Range of Koc values which were found for each PAH studied. (mg/l) Phenanthrene 4.3 - 4.6 190 - 33,000 Fluoranthrene 4.2 - 5.5 228 - 40,000 Pyrene 5.0 - 5.4 551 - 27,306 Benzo-a-pyrene 4.5 - 6.6 305 - 37,051 By varying the conditions needed in the batch sorption studies by using a constant and varying solids technique, the data produced considerably different isotherms for benzo-a-pyrene. The effect was not as readily apparent in the phenanthrene data. For BAP the following data summarizes the Freundlich parameters which described BAP sorption. 55 W. W W (mg/1) 4,000 3.33e4 0.88 10,000 2.82e4 0.83 20,000 1.89e4 0.82 I .. 1 2511 s .1 ’ (ppb) 10 7.21e-7 3.60 50' 4.62e-4 2.34 As previously noted, the Freundlich K is an indicator of the amount of absorption while l/n is an indicator of absorption intensity. For the varying solids technique, l/n remained relatively unchanged while the Freundlich K decreased with increasing solids. for the constant solids technique, K increased while 11 decreased with increasing initial BAP spike. The significance of this data is that simple predictions of BAP concentration in one phase of the system, either solid or water, by knowing the partition coefficient should be used with caution since, the results depend on isotherm procedure. Additionally, as noted by Figure 2.7, correcting the observed partition coefficient value by using a technique similar to Gschwend and Wu‘s or Hoke and Giesy may not be adequate for data which is generated by techniques similar to ours. 56 Chapter 3: Measurement of Phenanthrene and Benzo-a- pyrene binding to Dissolved Organic Carbon from Lake Michigan Sediments 3.1 Introduction A number of researchers have shown that hydrophobic organic compounds (HOCs) exist in "bound" forms associated with either dissolved or colloidal organic matter. Chiou et a1. (19) showed that the water solubility of HOC‘s was enhanced by humic and fulvic acid addition. Compounds with high water solubility exhibited no detectable solubility enhancement, however, more hydrophobic compounds such as DDT showed significant solubility enhancement. Other researchers have demonstrated the ability of organic colloids to alter the subsurface transport of contaminants (Schwarzenbach et. al., 1981; McCarthy et. al., 1989; Magee et. al., 1991, Bertsch, et. al., 1993) The role of particulate organic matter in decreasing accumulation of polynuclear aromatic hydrocarbons in aquatic biota has also been shown (McCarthy, 1983). Other researchers have identified the binding of HOC's as a reason for decreasing bio- availability of HOC's (Geisey, 1981). In order to evaluate the extent of binding of PAH‘s to dissolved organic carbon, it is necessary to measure the "free" and "bound" distribution of the compound as well as the amount of binding material in solution. The objective of this chapter is to describe two experimental techniques, fluorescence quenching and reverse phase separation, which have been developed by researchers for measuring PAH binding to dissolved organic carbon. Additionally, the chapter 57 describes the experiments which .were used to measure phenanthrene and benzo-a-pyrene binding to dissolved organic carbon from Lake Michigan Sediments. Fluorescence quenching is a technique originally presented by Gauthier (1986) for measuring the equilibrium constant which describes the interaction that hydrophobic fluorescent compounds have with dissolved organic carbon. The procedure is based on the observation that the fluorescence of the hydrophobic compound decreases proportionally to its association with organic carbon. The organic carbon inhibits the fluorescence of PAH's when it is present in solution. It is believed that this is due to binding with the PAH molecules. One researcher describes the process as a cage-like structure around the PAH which absorbs the energy normally dissipated as fluorescence (Morra, 1990). Fluorescence quenching has continued to be developed through other researchers including Gschwend and Backhus (1990), Morra, et. al. (1990), and Slautman (1992). The binding of hydrophobic chemicals to organic carbon is important in assessing the fate and transport of pollutants in environmental systems. The fluorescence quenching technique has been used to describe binding of PAH to organic carbon to assess the colloidal transport of PAH's in groundwater (Backhus and Gschwend, 1990; Magee, 1991) Reverse-phase separation was used by Landrum, et. al., (1984) to measure pollutant binding to dissolved organic carbon by physically separating the organic carbon bound and free phase of 58 pollutants at equilibrium. It was developed from the observation that humic-bound benzo-a-pyrene and other PAHs could be separated from the "freely dissolved" benzo-a-pyrene using XAD-4 resins (Landrum and Giesy, 1981). 3.2 Quantifying DOC Released from Lake MI Sediments In order to quantify PAH distribution in the aqueous phase, it “is necessary to quantify the sorbent transfer of solute binding material (in our case DOC) to solution. Voice (1983) noted the difficulties associated with defining the components of the aqueous phase. Experimental techniques are hindered by the fact that complete phase separation is difficult if not impossible to achieve. Under these conditions, operational definitions for "free" and "bound" compound must be set forth in experimental techniques. Eadie (1990) conducted a study of HOC distribution between particle bound, dissolved organic matter bound and freely dissolved constituents. Operational definitions were achieved by glass fiber filtration and reverse phase separation using SepPakr cartridges. His results indicated that for most compounds including benzo-a-pyrene, the free fraction was dominate. However, these studies were undertaken for natural water column conditions 1-5 ppm TOC and 0.2 to 5 ppm of total suspended matter. 59 In our experiments it was necessary to correlate TOC to some other measurable parameter since radiolabelled chemicals were used in the sorption experiments. The following experiments describe the correlation which was developed to quantify the aqueous DOC. 3.2.1 Materials and Methods Batch bottle point experiments were set up for the DOC transfer measurement similar to the experiments used for PAH sorption in chapter 1. A known quantity of sediment was placed in a 25 ml centrifuge tube and combined with a known quantity of deionized, reverse osmosis, and filtered water. The mixture was shaken on a wrist action shaker for 24 hours to allow equilibrium to be achieved. Initially, a kinetic study was performed by adding the same amount of sediment to several tubes and equilibrating for varying amounts of time. For the purposes of this study, the sediment was separated from solution by centrifugation at 12,000 RCF for 2 hours. Residual organic matter in solution both in the form of micro-particulates and dissolved material was defined as the sorbing phase resulting from sediment transfer. The instrument specifications which were used for this study are included in Appendix II. The quantification of the amount of total organic matter transferred from the sediment to the solution was accomplished 60 through a series of experiments. After solid separation by centrifugation, a portion of the supernatant was used to measure absorbance at 255 nm. Additional portions of the supernatant were used to evaluate the total organic carbon, TOC, by using a Shimadzu TOC analyzer. A separate experiment was conducted to evaluate turbidity in several of the samples by removing a 15 ml portion of the water from the tube and measuring on a turbidity meter. 3.2.2 Results and Discussion Kinetics of TOC desorption from freeze dried Lake Michigan Sediments were determined to be relatively fast. As shown in figure 3.1, greater than 80 % of the material desorbed in less than 5 hours. The remainder of the DOC slowly entered solution over an extended period (30 hours in this study). These kinetics, however, are slower than the time required for binding of PAH's to dissolved organic material as modeled by humic and fulvic acids using fluorescence quenching (Gschwend and Backhus 1990, Gauthier 1986, Slautman 1992). As shown in figure 3.2, the absorbance values correlated to the sediment concentration using a logarithmic regression. The regression equation, y = a * Xb, found to provide the best fit for the data, was the same form of equation used by Voice relating TOC to sediment concentration. Approximately 94 % of the scatter in the data is described by the logarithmic regression. The deviation from 61 on 9:.- .05.... Boo u m& .Axvoghmmow. + god. a x 56833.. 255233 95.25%. 5922.2 9.3 to 0.. Bob .8930 25090 «0 883m "Tm oSmE lelol ‘uquao aluefiao ”Bu: 62 :9: 60:82.83 =35.qu oooom oooov oooon oooom oooow » n p p p p n P b 33 . ~ .- Pd r 0.0 r v.0 :omumegcoocov Eon—Bow m> n3 8 oucmpeomnax "Nd oSmE md um 99: :- eaunqmsqv 63 linearity is possibly the result of readsorption by organic material at the higher solids concentration or alternately, an approach to solubility limits of the organics. Figure 3.3 shows that TOC can be determined as a function of absorbance. The correlation that we found was subsequently used in the DOC binding experiments to evaluate the amount of solute binding material in solution at equilibrium as TOC. An additional measurement was made to determine solution turbidity. This was done since other researchers have identified that incomplete phase separation of dissolved and particulate material can affect the measurement of Kdoc values for HOC's (Gschwend and Wu 1985, Voice 1985). Figure 3.4 shows the results obtained by correlating TOC and turbidity to absorbance. Under ideal assumptions, turbidity, defined as a- measure of the light scattering properties of a solution, measures particulate material. Absorbance, however, is a measure of the absorption of light at specific wavelengths and relates to dissolved material. The absorbance readings in our data from about 0.05 to 0.5 relate to a range in TOC of about 5 to 45 mg/l. This range in absorbance allows much more measurement ability than the 15 to 25 NTU range on a turbidity instrument. 64 md 323.522 «.0 0.0 Nd v.0 mmmd . 9m 38¢ + «.83 a > 29:63 52:22 93.. Eat ooo 8: m3 3 oogneofixx m> DOE and 05mm 10? om '00]. t/Bw 65 oocuaeoun< «to 0.0 Nd od md c or 4 I. n w m . w. N I. n ow r on 32 553.3. '0' 38.00.. Iall. 0338mm? m> bBESH use OOH "an oSmE 1.0—. Ion on ‘00]. ”But 66 The regression: TOC (mg/l) = 1.5522 + 73.064 * Abs R2 = 0.825 was subsequently used in the study to estimate DOC values from absorbance. 3.3 Fluorescence Quenching Fluorescence .quenching has been used by many researchers to study PAH partitioning to aqueous-phase organic material (Gschwend and Backhus, 1990; Gauthier, 1986; Slautman, 1992). Its advantage is that a physical separation of "free" and organic carbon "bound" components in solution is not necessary. Hence recovery and separation efficiencies do not hinder its use. Fluorescence quenching is founded on the assumption that the measured fluorescence intensity is decreased in proportion to the fluorescent compound's binding to a quencher (Gauthier, 1986). In natural waters, the principal quencher is believed to be dissolved organic carbon. Three mechanisms of fluorescence quenching are defined in the literature. Apparent quenching, referred to as the inner filter effect is due to attenuation of light at the excitation wavelength and absorption of light at the emission wavelength during a fluorescence measurement. Additionally, the fluorescent molecule can interact with a quencher by either association or collision mechanisms. The first is referred to as static quenching and the latter as dynamic 67 quenching (Gauthier 1986). All of the mechanisms may be present when measuring the decrease in fluorescence associated with a quencher. The mechanisms involved in binding of organic carbon with PAH‘s is static and dynamic quenching. Gauthier's method makes use of a fluorescence correction coefficient which defines the proportion of exciting and emitting light which is lost through absorption. Any remaining losses in the presence of the quencher are assumed to result from interactions with the quencher, either by binding deactivation (static quenching) or by collisional de-excitation (dynamic quenching) of the fluorescent molecule. The procedure relies on the assumption that the decreases in fluorescence which are observed in the presence of organic material are directly proportional to the extent of binding. A simple derivation of this interaction as a conditional equilibrium equation is included in Appendix 1. The Stern-Volmer equation is an expression which relates the ratio of fluorescence in the presence to fluorescence in the absence of a quencher with the partitioning coefficient, Kdoc, and the concentration of quencher (DOC) in the sample. Fo/F = 1 + Kdoc * DOC Corrections for absorption of the excitation and emission radiation are obtained by measuring absorption at the fluorescence 68 excitation and emission wavelengths. Miller, 1981, has derived the correction factor for perpendicular cell geometry. A summary of this derivation is also included in Appendix I. The decrease in fluorescence intensity after the correction has been applied is due to interaction with a quencher. Miller reports that for a correction factor greater than 1.8, the correction is increasingly inaccurate. Due to the relatively low absorbance values for the DOC used in our experiments, this value was not exceeded. Gschwend and Backhus (1990) identified two possible problems to the Gauthier procedure. The first suggested that the DOM-PAH complex may fluoresce. The second identified the need to correct for glassware sorption when compounds with high hydrophobicity are used. Slautman (1992), experimented with these ideas for a number of PAH compounds absorbing to humic and fulvic acids. He noted that the quantum efficiency of the PAH-DOM complex approached zero for all the PAH's that were studied. Additionally, he found that the technique of Gauthier was satisfactory for PAH‘s of moderate hydrophobicity. In order to correct for the fluorescence of the DOM-PAH complex, the following equation can be developed (Gschwend and Backhus, 1990): Fo/F = (1 + o*Kdoc*DOC)/(l + K doc*DOC) where, o = quantum yield of PAH—DOM complex 69 This equation is essentially a modified Stern-Volmer expression with the Fo/F ratio defined as follows: Fo/F = [PAlem/i [PAmfmmflPAmbml Additionally, Gschwend and Backhus, (1990) note that by measuring the fluorescence of a sample over time, glassware sorption can be eliminated by extrapolating to time zero. 3.3.] Methods and Materials for Fluorescence Quenching Measurements of Phenanthrene and Benzo-a-pyrene For the purposes of this study, the phenanthrene binding coefficients to dissolved organic carbon from Lake Michigan sediments were estimated using Gauthier's technique. It was assumed that little or no glassware sorption took place. Slautman (1992) indicates that this approach is valid for the moderately hydrophobic PAH's. The technique for benzo-a-pyrene, however, implemented the procedure developed by Backhus and Gschwend (1990) to correct for glassware sorption. The instrument specifications and settings are included in appendix ll. For measurement of phenanthrene, a Perkin Elmer LS 50 spectrafluorimeter with a xenon arc lamp for the source was used. limitation and emission wavelengths were set at 255 nm and 365 nm respectively since a high intensity peak occurred at these wavelengths. The excitation and emission slits were both set at 5 nm 70 in order to maintain the resolution of the peak while allowing maximum intensity readings. Activity of 14C in the samples was measured on a Beckman liquid scintillation counter. Absorbances were measured on a Shimadzu UV spectrophotometer. The samples which were measured in this portion of the study came from the sediment sorption studies which were completed in chapter 1. The initial step in the procedure was to estimate the 14C activity and the fluorescence intensity of the blank sample in order to relate the two measurements. ‘This procedure was necessary to estimate the total PAH in solution by fluorescence in the absence of the quencher. Accordingly, the disintegrations per minute of 1“C activity and the fluorescence of each sample was measured on a small portion of aqueous sample which had been separated from the sediments by centrifuging. The sample was withdrawn from the centrifuge tubes by disposable glass pipettes and placed in a quartz cuvette. Initial experiments were conducted to identify the appr0priate excitation and emission wavelengths for the fluorescence measurements. The goal was to choose wavelengths which resulted in an intensity peak from the PAH fluorescence. Figure 3.5 demonstrates the fluorescence 71 :(tgsuatu' A 28$ 88on ousoomoeoafi 0:35:20an "m. 72 intensity of phenanthrene over a range of excitation wavelengths from 200 to 350 nm and emission wavelengths from 300 to 500 nm. The phenanthrene peak at 250 nm excitation and 365 nm emission was chosen for the measurement. Similar experiments were conducted for benzo-a-pyrene and an emission and excitation wavelength of 380 and 445 nm were chosen respectively. The fluorescence measurements of the benzo-a- pyrene solutions were measured over a time period of 15 minutes. Time zero was determined at the point of filling the cuvette with the sample. Figure 3.6 shows an example of the data from this procedure. The measured fluorescence was determined by extrapolating the data by linear regression to time zero and reading the intensity value. The absorbance of each sample was measured at both the fluorescence excitation and emission wavelengths to be used for the fluorescence correction factor. Also, the absorbance of the sample was measured at 255 nm to correlate the total organic carbon from Figure 3.3. In the fluorescence measurement of phenanthrene, several samples had concentrations high enough to exceed the instrument range. These samples were diluted by adding a known amount of distilled water to the sample cuvette. A dilution factor was obtained by taking the sample weight divided by the sample plus dilution water weight. 73 oomw 03 .08.... 000 F com 9.3 a 9m x1388 . 8.8. u s a :ouflommbxm oocoumoeosfi ocobaéoucom 6d oesmmm Ausuetul GOUGOSGJOHH 74 About five ml of additional sample was taken from each tube and placed in liquid scintillation vials. The weight of each sample was determined to the nearest tenth of a gram by tarring the vial and measuring the sample weight. Ten ml of high performance liquid scintillation cocktail was then added to each vial. The vials were capped, shaken and counted for three ten—minute repetitions on the Beckman liquid scintillation counter. 3.3.2 Results and Discussion: Calculation of Kdoc Table 3.1 shows the data reduction and calculations which were used for the Kdoc of phenanthrene. The 14C activity of the aqueous sample is shown in column 2. The fluorescence intensity in the absence of a quencher was estimated by multiplying the 1“C aqueous activity by the equivalent fluorescence intensity shown at the top of the table. This calculation was necessary to determine F0. The fluorescence intensity estimating the amount of free compound in the samples is shown in column four. The free fluorescence was multiplied by the dilution factor where necessary to determine the actual sample fluorescence. The value for the actual fluorescence was entered as F total. The absorbances at the emission and excitation wavelengths were then used to estimate the factor which corrects for the inner filter effect. The full derivation of this equation is included in Appendix 1. As shown, the corrected "free" fluorescence is obtained onoha—u—zu-nnUSqu .MAF-ma—U—nnv-ag an-unvnvtuv.:u:—.Y~ u~ .Ft «uni-«.5 7S 50006 00.00 0 PM 000 50 00. 5 8.0 00.0 00655. 00... 00650. 00600.5 000.00... I 500010 00.5— mvd 00.005 0.4.5 00.0 00.0 05..ch 00.5 05.40». 00005.5 00+000... 0— ~0+00 v.0 00.0 00.0 05.000 2... 00.0 00.0 00.0.5 05.5 00.0 5. 00005.0 00+u0~.m 0 00+0mm... 05.5 00.05 00.0005 0 5.5 00.0 9.0 05050— 0.; ~5. —00 v0+00v... 50050.5 0 005006 00.5 .0. 50 0~.500 00. — 00.0 50.0 00.500 00... 05.000 v0+0~0.~ 50.000... 5 00000.5 0~.0 .05 00.5000 00., 00.0 .00 00.5000 550 0.100 v0+000.0 50+m55.~ 0 00.5.5.0; 00.0.5 00.0.. 05.050. 00.5 00.0 5.0 05.055 00.0 0.0m— v0+000... 50000... 0 ~0+0550 00.0 0Y5 00.00 .N 0.; 5.0 00.0 00000.. 3.0 00.555 .0000; 50.050.— v ~0+0~m.m 0 :— 0 —.5 v0.0..0— NP... 00.0 00.0 9400»... 5—.~ 05.000 .000 p... 500.000.. 0 00000.0 00.0 05.0 00.0.. 3 FN— 00.0 .V ...0 0~.000 00. — 0~.000 .0000; 00+00~0 N .m0+mmm.~ 000— m5.0~ 00.500 55.5 00.0 05.0 0m.~0~ mm; 00.0..N 00+0v~.0 00+000.5 P <9. 63. :08 .85 ”to”. 033:3 .u. cozootou 000 © B< 000 © B< .33 u. 3.5.5 a. on. .5250 29:3. ..5000..00.0 «ASE 000 .z .E ~0.m\E% 5000055§5 5.32:. 00000 no... "HEEL: 8:38.02“. 0:255:05. 0:30:30 8:080:03... 3.0 2an 76 be multiplying the correction factor by F total. Knowing F0 and the corrected fluorescence, F, the Stern Volmer equation could be evaluated. The procedure for determining the Stern-Volmer constant is also included in appendix 1. In our experiments, this constant is equal to the binding constant when the dissolved organic carbon concentration is substituted in the Stern-Volmer expression. For these experiments, the dissolved organic carbon content is estimated by substituting the absorbance measured at 255 nm into the regression equation shown in Figure 3.3. Table 3.2 shows the data reduction for benzo-a-pyrene. The procedure was similar to phenanthrene except that the fluorescence at time zero was extrapolated from fluorescence measurements taken over fifteen minutes. The benzo-a-pyrene timed fluorescence data is included in appendix 1. Referring to Table 3.1, the measured 14C activity for the 11 phenanthrene spiked samples is consistent with the varying and constant sediment isotherm procedures discussed in Chapter 1. The first five samples represent constant sediment trials with varying phenanthrene spike. Accordingly, the measured disintegrations per minute per liter of sample increased with increasing spike. Ftotal after adjustment for dilution also increases over the five samples with increasing spike. Column 12 demonstrates that the estimated 77 00000.. 0 ..NN 00... ~v.000 00.. 00.0 00.0 Nv.000 00. . 0.000 00000.0 00050.5 0.0..t~.0smm,01.| 0. M00000 000m 0..~ 00.0.0 00.. 00.0 00.0 000.0 00.. 00.0.0 0005... 00000.0 00.00508 .0. 0v.- .5.0 ....30 00.. 00.0 00.0 36.0 00.. 36.0 00000.0 00000.. 5. 00. . 00.0 00.0 00.0 00. . 00000. . 00000.0 0. 00.. 00.0 00.0 00.0 00.. 00050. . 00000.0 0. 00050.0 00.0 00.0 ~0.v- 00.. 00.0 00.0 00000 00.. ~0.v- 00000.. 00000.0 00.0030 v. 00000.0 SEO 00.0 00600 00.. 00.0 00.0 00600 00.. 00000 00005.0 00000.0 00.00505 0. 00000.. .00 ...~ .00 .N 00.. 00.0 00.0 0.0 .N 00.. V0.0 .N 0000....4 00050.. 00.00005 N. 000006 00... ....5 05.000 00. 00.0 00.0 05.000 00.. 05.000 00050.0 00000.0 00. .0000. .. 0003.0 00.... 50.0. 05.00. 00.. 00.0 00.0 05.00. 00.. 05.00. 00000.0 00000.0 0N..5000 0. 000m 5.. 0...... 00.0 00.000 00.. 00.0 00.0 06100114000. 00.000 0000.. 000.0... 00.00 .00. 0 00000. 00.... 00.0 00.000 00.. 00.0 00.0 00.000 00.. 00.000 0005... 00000... 00.0050. 0 000.0. 00.... 0v.~ .5000 00.. 00.0 00.0 .5000 00.. .5000 00000.5 00000.0 000.000. 5 .0.00¢0.0 50.... 0 ... 00. .00 00.. 00.0 00.0 00.00 00.. 00.00 00000.0 0000.... 00000.0. 0 ..5.0~ 0T0 0.500 00.. 00.0 00.0 0.500 00.. .0500 00000.0 .00000 0 000500 00.5. 00. . o0.¢0¢ 00.. 00.0 00.0 00.v0v 00. . 0000.. 000500 000.0. 00.000 .0. v ..00.0.0 .0... 55. 00.50~ 00.. 00.0 00.0 00.500 00.. 0N.50~ 00000.0 000 .0. 00.. .550. 0 00000.0 00.5 05.~ 0.00. 00.. 00.0 00.0 0.00. 00.. 0.00. ~0000.0 000.00 00.50005 N 00000.. ~00 0¢.0 00.00. 00.. 00.0 00.0 00.0w. 00.. 00.00. 00000.5 00000.0 0.0.0.0.. . . Scan <9. .03. <0E .090 “.50“. 030250 .... cozootou 0.... @ mn< 000 @ B< .23 a. co......0 H. o... .5250 02“. 29:3. Rood 15% 88093.2. :23... 08 .8 San w<0 50:22.02... 3:38.03: gobaééugm 0:20:30 00:83:02.”. ”N0 0.00... 78 TOC values for the constant sediment procedure ranged from 9.5 to 12.1, indicating a range of variability of 2.6 mg/l of TOC Similarly for the varying sediment procedure, the estimated TOC increased with increasing sediment concentration. Accordingly, the measured fluorescence of the constant phenanthrene spike decreased for samples 6 through 11. This decrease was due to the three mechanisms described previously, including apparent, static and dynamic quenching. After the correction for absorbance measurements at 250 and 365 nm (apparent quenching), column 10 shows the corrected fluorescence representing the concentration of free phenanthrene in each sample. Referring to Table 3.2, the measured l4C activity of the benzo- a-pyrene and the fluorescence values were consistent with the constant and varying sediment experiments. Column 5 shows the 14C activity in the aqueous portion of the sediment water mix. Samples 1 through 5 are varying sediment experiments with constant benzo- a-pyrene spike. The TOC values estimated in column 15 increased with increasing sediment concentration and F0 decreased. Samples 6 through 11, 12 through 14, and 17 through 19 represent constant sediment procedures which resulted in TOC values on average of 14, 8.5 and 22.3 mg/l TOC respectively. 79 For the benzo-a-pyrene experiments, the dilution factor and correction factor were both one for all samples. This occurred because the undiluted samples were within the measurement range of the fluorimeter (less than 1000 intensity units). Additionally, the absorbance at the emission and excitation wavelengths of 380 nm and 445 nm respectively, was negligible, indicating that all quenching was either static or dynamic and not apparent quenching. As shown by Backhus and Gschwend (1990), the fluorescence measurement for‘ extensively hydrophobic compounds must be corrected for glass absorption. A linear regression was applied to extrapolate the measured fluorescence to time zero. The fluorescence at time zero was the value tabulated in the spreadsheet, Table 3.2. Apparent from the Figure 3.6 is the fact that the measured fluorescence changed little over the 15 minute time period indicating little absorption to the glassware on that time scale. 3.3.3 Conclusions: Fluorescence Quenching In both the phenanthrene and benzo-a-pyrene data, using the results for Fo/F, Kdoc was calculated from the Stern-Volmer expression by the formula: The Kdoc values which were calculated for phenanthrene and benzo-a-pyrene varied widely with sediment concentration. This 80 variation is demonstrated in Figure 3.7 and 3.8. The range of Kdoc values obtained using the fluorescence technique is shown below. BAH MW, 1.22.1919, (mg/l) Phenanthrene 5.20 - 25.60 1.6 - 3.6 Benzo-a-pyrene 5.02 - 25.74 3.7 - 6.0 For both phenanthrene and benzo-a-pyrene, the Kdoc calculated by fluorescence quenching shows a decrease with increasing sorbent concentration. Although the dependence of Koc on sorbent concentration has been shown by a variety of researchers, the relationship of Kdoc with changing sorbent concentration has not been well documented. This apparent dependence on solids concentration or dissolved organic matter concentration has been noted by other researchers. McCarthy and Jimenez, 1985, found that the binding affinity of benzo-a-pyrene, anthracene and 81 <9: .cosflucoocou aceEBom 889 0009 coop cow .prLP h P PupphL. p p n-pubLb p . OF EoEtogxm 3ng 835x 9 ~56 u ~om oaocfiamqonm 5m 053m IIIIW 88F 82 <9: .cozmbcoocou EoEiom 00009 089 coo? » . p . . p . . p L p p P . p . . a H . a 0 I O o o . a Q o o a a a . m a m. a a . B E . a n B 32a 3.2% . 33.0 n ~é 8036i .. $835. a a 9.2825 83828.... a Ewe ... mé mmme 3x .. «.3me 2 u x T m. 8.! .ouzoomoeosfi cam unmam 385m ogobfléénaom ”mam oSmEIl mow mo— now '09)! ,- 5 83 benzanthracene decreased with increasing dissolved humic material. Landrum, 1984, found similar results for benzo-a-pyrene and anthracene. 3.4 Reverse Phase Separation The reverse phase separation method for determining pollutant binding to dissolved organic carbon was developed by Landrum et. al. (1984). The organic carbon bound pollutant was separated from ”freely dissolved" pollutant by using a Sep-Pak C-l8 cartridge. Organic carbon bound pollutant passed through, while the unbound pollutants were retained by the column. The partition coefficient was calculated as (grams of pollutant bound/grams of organic carbon)/(grams of pollutant freely dissolved/milliliter). This technique was developed from the observation that an anomalous breakthrough of benzo a pyrene occurred during concentration with Amberlite XAD-4 resin from aqueous solution (Landrum and Giesy, 1981). These resins among many absorbing materials were used to concentrate pollutants at trace concentrations within environmental samples. The breakthrough of the pollutants was determined to be the result of binding to dissolved minerals and organics. In the experiments with benzo-a-pyrene using the reverse phase column (Landrum, 1984), it was noted that minimal contact 84 time between the column and humic-pollutant complex minimized the potential for pollutaanOC complex dissociation because of column interactions. The procedure used a flow-rate of about 12 ml/min. Where breakthrough of free compound occurred in the absence of DOC, an empirical correction was used. It is thought that pollutants bound to dissolved organic matter pass through the cartridge at pH sufficiently high (greater than 5) to polarize the humic substances. In the following experiments, we have used EmporeR extraction disks as an alternate sorbent to study reverse phase separation of free and bound phenanthrene and benzo-a-pyrene. The filter disks, enmeshed in special fibrils, are made of C-18 moiety bonded particles. A filtration apparatus, consisting of a vacuum flask stoppered with a glass frit and filter clamp and attached to a vacuum meter and pump were then used to perform the extractions. It is suspected that the C-18 coated disk will eliminate the potential for erroneous data due to short circuiting. Short circuiting was noted to be a problem for some pollutants using the Sep-Pak column even at low flow conditions. As previously noted a correction was applied to the "bound" concentration to adjust for the amount of "free" compound passing through the column (Landrum, 1984). Additionally, the enhanced contact provided by the even particle distribution within the EmporeR disk should permit much higher flow rates and reduce the potential desorption of the "bound" 85 contaminant. This condition of increasing bound contaminant with increasing flow was also noted by Landrum, 1984. 3.4.1 Materials and Methods: EmporeR Disk Extraction The initial experiment was designed to determine whether breakthrough of a solution of 14C labelled pyrene would occur at high flow rates. The vacuum filter apparatus described above was connected to a vacuum source metered by a Vacu-trol pressure gauge. A range of pressures from 200 to 600 mm of Hg were supplied to filter 10 ml of sample prepared at about 10,000 dpm. The disks were pre-conditioned using the following procedure as described by the manufacturer: 1. Flush with 10 ml MeC12 2. Flush with 10 ml MeOH 3. Flush with 10 ml D1 The elution solvent was MeC12 and it was used initially to flush contaminants from the disk. Methanol was then flushed through to remove the MeC12 and prepare the disk for a DI water flush. After rinsing the disk with DI water in the final step, the disk was not allowed to dry prior to extracting the samples. For each sample, the procedure was repeated with a new disk. Immediately following the preconditioning step while a meniscus of DI water was still visible, 10 ml of sample were filtered 86 through the EmporeR disk at varying flow rates, corresponding to varying pressure. The disks were filtered until dry, and the supernatant was combined with 5 ml of LSC cocktail and counted using the method described in Appendix II. Subsequently, 10 ml of a MeC12/MeOH mixture in a 80/20 ratio was used to extract the disk. The extractant was transferred to a scintillation vial, combined with 5 ml of LSC cocktail and counted for 1“C activity.. After the extraction, the disk itself was also transferred to an LSC vial, combined with 5 ml of LSC cocktail and counted. Figure 3.9 identifies the flowrate/pressure calibration curve determined for the EmporeR disks using DI water. This curve was completed to approximate the flow rate which corresponded to a given pressure. For the breakthrough experiment, the flow rates were varied between 6 to 20 ml/minute by adjusting the pressure in order to determine if breakthrough would occur. Over this pressure range, however, no significant change occurred. Greater than 99% of the pyrene was absorbed to the disk at all pressures which were tested. With these results, a pressure of 400 mm Hg was chosen to extract the DOM complexed samples using the procedure described above. The "bound" constituent was determined .by counting the 14C activity of the filtrate, while the "free" constituent was determined by extraction absorbed PAH from the disk and counting the 14C 87 00¢ a: SS 6.5395 Eaaoa> com DON P . $3.0 I 9m xmémmmté ... mused - u > 3 VEQ ouoaam smack: 88-30E ”ad gamma ‘ornu mom “IN/II.“ 88 activity. The following equation was used to determine the partitioning coefficient to aqueous DOM: Where DOC was estimated using the correlation shown in Figure 14. Extraction efficiencies were necessary to adjust the concentration of the "free" compound because not all of the absorbed PAH could be removed from the disk. The following steps detail our laboratory experiments: 1. Ten ml of water sample was removed from the PAH batch sorption experiments and filtered through the EmporeR disk at 15 ml/min, 400 mm Hg. 2. The filtrate was combined with 5 ml of LSC cocktail and counted using the method described in appendix II. 3. After filtering the disk to dryness, the disk was extracted using 10 ml of 80/20, MeC12/MeOH mixture. The extractant was combined with 5 ml of LSC cocktail and counted. 4. The disk was then combined with 5 ml of LSC cocktail and counted. 5. The "free" measurement obtained from the disk extraction was then adjusted to reflect the extraction efficiency. 6. DOC was estimated using absorbance at 255 and Cbound was normalized to the organic carbon. 7' Kdoc = C bound, C free 89 3.4.2 Results and Discussion: Emporer Disk Extraction Tables 3.3 and 3.4 show the data reduction which was used for the EmporeR disk extraction method. The supernatant was the material passing through the disk. It represented the organic carbon bound PAH. The elution of the disk itself using MeC12 was counted for the free compound measurement. Additionally, the disk itself was placed in scintillation cocktail and counted because the extraction was not fully efficient. Since the total aqueous 14C activity was previously measured in the PAH sorption studies, a recovery estimate was calculated by adding the activity from the supernatant, the eluant, and the disk, and dividing the sum by the total activity. The recovery percentage is shown in the tables. It was assumed the estimated "free" activity determined from the disk extraction should be adjusted by the recovery efficiency since its value was measured directly by the Emporer extraction. The value was entered as adjusted "free" concentration in the tables. Knowing the activity of the "bound" portion which passed through the disk and the "free" concentration which was extracted from the disk, a partitioning coefficient was calculated from the following expression: Kdoc = [PAHmemdn [PAHlfm’kDOC] 90 0 mo+m$é mo+mmod mmdv mo+m Fm; mo+w-é mo+u-é wmv Pfimtmm m fiom Z 1-51 3.32% .232.“ cod oo+mood oo+mood mméem: omdw o_. mo+mmmé mo+u~ fim moKm moémms @96de ¢o+m~m.~ m E magnmm 3.3 m 1-- , mo+m~mé no+mmmg 5.8 o P+mmo.~ m0+m-zm ¢o+mn~d 2.0.. ammo: mmé m ,l! 8.83 23%.. mm? 0 349m mofimmd ¢o+mmmm 8.32 mm. :3 mam 1% l - 8+“ _ S BJmNN 38 0 Two: 8.9.: 8+ng mm 2 3.8. ~¢.~ m I :2 . mo+mmm4 no+m Fm... Nwdm 0 Ti Pod m0+mmod vo+mmo.m no: mmdmmw NOK m mo+mom.— ~o+w¢vé ¢¢.mm ow+mmmé moi—{K ¢o+mzfi mmm— mndmmm «AK v mo+mmmé 50.330... ¢o.om o 7.3.30.9 mo+mm~d ¢o+mm~.m om: mwdnmw toK m ...... mo+mmw._. wo+mvm.w Fmdm 07mg; moi—Nd ¢o+mpm.m Omop vmdemm 00.» N Bag; .23me 3.4m 03mm; 8.93 893 0mm :82 a: F ....... 11.3“... 30681 on; bo>0uom UOH 9356 annm .E or Ego 2mg <9: .vom _\.mlE .uoo a oEEMm. uonm “089.9% venom .xEqu .oom cozam ucauanaam noumEzmm . 88E“ 28.5. oaocficmconm .aozfioaom 895 383% “Wm 058. 91 mo+moms mo+m~o.m Nugmm mo+mom.m mo+m :4 mndmw Omdpop chum mndm SN m _.N~ mp vo+wom.m mo+mmo.~ m fium mofiwmfi mo+mo~._. mm.mmw mmdnm wmdomp m fimmvom mm.- 2 .vo+mom.~ «6.53.6 56m moéomé ¢o+wvw.m on. we made NEmov vvémmow mva .2 ¢o+m F Nd mo+mmm.m QOn o —+moo.m mo+uwN~ 09.5 I vfimwm— 006. SN mmdwmm mm.w m... .EDzn .znzu oo+moo.o 09.890 00.0 00.0 00.0 mv.moo¢ mvd m F Wb+wmmé mo+mm~.m ovdw o—vaé m0+mm~.~ vmdmm mo.~mmp mmdwmp mwém—v mmd 3 r Eben 2232* oo+mood 09.806 006 00.0 00.0 mmN Pov v¢.m m— .EmYm ¢o+m:..m mmdm mo+mm~K vo+m¢wd D‘dmv 3.va wad—m ammo; vmd NF Nowuummé mo+w~m.v -.mm 0 7mm fim mo+w FNM Nm. P F: m 9.003 nwémom 550mm mmé- Z .vo+mmm.~ mo+mmo.m nmdm o—+mw~.P mo+wnm.w pmfimmp mmfipmp _.~.¢mm— m¢.mmmm mmép op 532% 332% 09.306 oo+mood cod cod cod vmdnoop ové— m No+mm ...m mo+mm~u~ when mo+wmfiw mo+w¢o.~ m~.wmo— m ".mmm mmfimmp mo.m¢wm ON: m wofived mo+mmvé 92.0 mo+mwm.m mo+wnmé Nodmm wmémm mwémmp mmdnmm MN: N ¢o+u~mé vo+mmmfi omén mo+m=m.m ¢o+mmm.m mm.mmm am... pm mmd Fm mammoop 3.3 o vo+wmo.~ vo+m F Em 3.9m mo+mm fi— vo+mv~.v Noémm v—dmp nwfiom @5953. vaN m ¢o+mmo.N mo+mmo.— mmdm mo+mo_..~ vc+w—o.m 360m mm.mm~ mmdmm voémmmp no.2 ¢ vo+mmfi~ mo+wmmé ovém mo+mmm.m voJmYm mm. ..mm mmé pm mvdmv mmdmmn vmép m ¢o+mmmK mo+mn P; omdm mo+mmm.m mo+woo.— ovdmv m¢. pvm mmdom modemm 3.5 m Wo+umod mo+mn~.~ wmdm o P+mv P; m0+w¢mé vndmm 82mm: 3.2m mfmva No.m — 3; 988”. 093458 22.32. S 2% 2.5 2% <8. .8m :9: .08 a 29:8 603. 3523‘ venom {Eat 60¢ :20 cozam cfiwanam vougzmm -L 2095. oeanw SomEm oaobaawéucom .coufiomom 82m 855m Jim 2an 92 Figures 3.7 and 3.8 show the Kdoc values determined from the above expression and plotted as a function of solids concentration. As apparent in these figures, the Kdoc for phenanthrene did not exhibit a dependence on solid concentration while the Kdoc for benzo- a-pyrene decreased with increasing solids in the system. This apparent dependence on solids concentration or dissolved organic matter concentration has been noted by other researchers. McCarthy and Jimenez, 1985, found that the binding affinity of benzo-a- pyrene, anthracene and benzanthracene decreased with increasing dissolved humic material. Landrum, 1984, found similar results for benzo-a-pyrene and anthracene. 3.4.3 Conclusions: EmporeR Disk Extraction A summary of the Kdoc values obtained using the Empore Extraction technique appears in the following table: BAH Wanna. 108 Km; (mg/l) Phenanthrene 2.42 - 30.15 3.1 - 3.3 Benzo-a-pyrene 5.02 - 25.74 3.9 - 4.9 To demonstrate a correction technique for the solid phase K0c values which were obtained in Chapter 1, the Kdoc values which were measured by reverse phase were applied to the benzo-a-pyrene sorption data using the following equation: 93 Koc = (Cs + C"bound")/C"free" This correction includes the amount bound in solution as part of the total amount bound to the sediments and includes only the ”free" concentration in the aqueous term. Figure 3.10 shows that the corrected K0c value is higher because of the correction, however, the corrected K0c still shows a decreasing trend with increasing solids concentration. The significance of this data is that we have demonstrated the range of Kdoc values which may be obtained by the fluorescence quenching technique and the reverse technique. It also demonstrates that. measured values of Kdoc using current techniques are not sufficient to describe the dependence that Kdoc has on solid concentration by correcting for the amount bound in solution. 94 OOOOM :9: 66582850 29:53 oooow 0000 F F - 890 a N5. 3-23m.~-v<9 .. $383 ... F 03. 86252.: a mmmd u N 325:83 $8205.. as. U was .. NE a .83-..." . $833 a > n n 32.0.35 .39: .03. 0 Bad I Ncm 858.9} . m+oon Ed n > .u w or > \I’ O I oaobaéénaom 63% gauges new $602 ”ode 05mm cox 112 4.2.2 Non-Linear Parameter Estimation The final procedure in modeling the benzo-a-pyrene data was to develop an expression for observed Kp which eliminated the non- equilibrium Kx present in Voice's model and allowed a regression to estimate K1 and K2. In order to accomplish this, the equation was intended to be written in terms of the Cf,“ which was determined experimentally in our system. The expression for KP is then: Kp= (Cm*Kl "l' Cfree*Kdoc*DOC*K2)/(Cfree+ Cfree*Kdoc*DOC) Where: Cm,e = "free" benzo-a-pyrene in solution Kdoc = aqueous distribution coefficient DOC = dissolved organic carbon K1, K2: model parameters This expression describes the same sink model which was developed by Voice, however, it is written in terms of the experimentally determined Cfrec value. The equation for K1) was then applied to the SYSTAT Non-linear Parameter Estimation technique to determine K1 and K2. The residuals and regression information are included in Appendix V. K1 and K2 were determined to be: K1: 5.9x 103 K2: 3.6x 103 113 Using the K1 and K2 estimations, the values for K0c at each Cf,“ measurement were then calculated with the intent of showing how model predicted K0c values varied with solid concentration. Experimental and calculated K0c values are shown in Figure 4.11 as a function of solid concentration. The experimental values are shown as graph points and the model values are shown as a line. As can be seen, the heterogeneous solute model with the modification for the Cfme term does not describe a decrease in K0c which approximates that which is observed experimentally. The presence of the non- equilibrium Kx value in Voice's model appears to make a significant- contribution in describing the observed data. The additional degree of freedom provided by the term Kx allows the data to be fit better. 114 ooooow =9: .:o_~8.coocoo 2.0m oooor — I b F b b I I b coop ..fimaa a oooow . un rtedumv. mwmdu 5. oaobaéoucom .SM EEoEtonxm 00m .0002 ":6 0.53m r 882 o O oooooow 115 Conclusions An understanding of the distribution of PAH compounds in sediment/water systems is a complex process. Laboratory sorptionstudies provide at best only a partial view of actual field phenomena. Interpretations of experimental results are obscured by inefficient compound recovery procedures, operational definitions for "free" and "bound" contaminant, and limits in defining particulate as opposed to freely dissolved organic material. Within this study, an attempt was made to evaluate sediment sorption of four PAH compounds exhibiting a range of hydrophobicities. We found that apparent K0c values determined by a varying solid sorption technique showed a dependence on solid concentration. The observed value of apparent K0c decreased with increasing solid concentration. Generally, this dependence appeared to increase for increasing compound hydrophobicity. A similar effect is noted in field data from a study undertaken within the Grand Calumet River (Hoke and Giesy 1992), however, the evaluation was based on foe as opposed to solid concentration. An approach to adjust the apparent K0c by subtracting the amount of "bound" compound from theaqueous phase did not correct for the solid dependence observed in the phenanthrene and benzo-a- pyrene data. This procedure was completed using values of "free" compound which were determined by the fluorescence quenching and reverse phase techniques. 116 The varying solid and constant solid isotherm techniques for benzo-a-pyrene produced a series of curves which are similar to those produced for heterogeneous solute partitioning (Voice, 1984). Model data obtained using the solute complexation model developed by Voice 1985, was capable of describing the experimental data. When we introduced a term for Cf,“ into the solute complexation model equations and applied a non-linear parameter estimation for the coefficients K1 and K2, however, the model failed to adequately describe the data. This observation suggests that either the non- equilibrium distribution coefficient which is incorporated in the derivation of Voice's model is a significant factor in the ability of the model to describe heterogeneous solute partitioning, or that experimentally determined values of "free" compound were not capable of calibrating the model to the observed solid phase partitioning data for benzo-a-pyrene. 117 Future Research In terms of experimental techniques, future research to provide a more rigorous separation of particulate and aqueous dissolved organic material should continue. Additionally, techniques which are intended to estimate the "free" and "bound" contaminant in the aqueous phase should continue to be refined. Typically, these techniques provide operational definitions which need to be evaluated in order to define their limitations and applicability to different compounds and different sorbents. With respect to modeling, many approaches and hypothesis have been suggested by different researchers. Our research used the solute complexation model to evaluate experimental partitioning data. Other models are available, however, and the applicability of these models needs to be evaluated. Although the solute complexation model could be calibrated to the experimental sorption data for benzo—a-pyrene, it is not known how closely model data predict similar environmental systems. The variation in observed partitioning with foe which was apparent in data from the Grand Calumet may be a phenomena parallel to laboratory data. More field studies of this effect should be conducted. 118 REFERENCELIST WWW, Edited by Werner Stumm, John Wiley and Sons, New York 1987, pg 7-9. Bertch, P.M., J.M. Novak, (1993), Pyrene sorption by Water Soluble Organic Carbon, Environ. Sci. Technol., 27, 398-402. Booth P.N., M.A. Jacobson, (1992) Development of Cleanup Standards at Superfund Sites: An Evaluation of Consistency, J. Air Waste Manage. Assoc., 42, 762-766. Briggs, G. G., (1973), A Simple relation Ship Between soil Sorption of Organic Chemicals and Their Octanol/Water Partition coefficients WW II 475- 478. Carter, C.W., I.H. Suffet, (1982) Binding of DDT to Dissolved Humic Materials, Environ. Sci. Technol., 16, 735-740. Chiou, C.T., V.H. Freed, R.L. Kohnert, (1977) Partition Coefficient and Bioaccumulation of Selected Organic Chemicals, Environ. Sci. technol., 11, 475-478. Chiou, C.T.; P.E. Porter, D.W. Schmeddling, (1983), Partition Equilibria of Non-ionic Organic Compounds Between Soil Organic Matter and Water, Environ. Sci. Technol., 4, 227-230. Curl, R.L.; G.A. Keolian, (1984) Implicit-Adsorbate Model for Apparent Anomalies with Organic Adsorption on Natural Adsorbents, Environ. Sci. Technol., 18, 916-922. DiToro, D.M., (1991), Technical Basis for Establishing Sediment Quality Criteria for Nonionic Organic Chemicals Using Equilibrium Partitioning, Environ. Toxicol. Chem 10, 1541-1583 DiToro, D.M., J.D. mahoney, P.R. Kirchgraber, A.L. O'Byrne, L.R. Pasquale, D.C. Piccinilil, (1986) Effects of Non-reversibility, Partcle concentration, Ionic Strength on Heavy Metal Sorption, Environ. Sci. Technol., 20, 55-61. 119 Eadie, BL (1990), Three-phase Partitioning of Hydrophobic Organic Compounds In Great Lakes Waters, Chemosphere, 20 Nos 1- 2 pp 161-178. Gauthier, T.D., E.C. Shane, W.F. Guerin, W.R. Seitz, C.L. Grant (1987), Fluorescence Quenching Method for Determining Equilibrium Constants for PAH Binding to Dissolved Humic Materials, Environ. Sci Technol. 20, 1162-1166 Gschwend P.M., D.A. Backhus, (1990) Fluorescent Polycyclic Aromatic Hydrocarbons as Probes for Studying the Impact of Colloids on Pollutant Transport in Groundwater, Environ. Sci. Technol, 24, 1214-1223. Gschwend, P.M. and S. Wu (1985), On the Constancy of Sediment Water Partition coefficients of Hydrophobic Organic Pollutants, Environ. Sci. Technol., 19, 90-96. Handbook of Environmental Data on Organic Chemicals Hoke, R.A., J .P. Giesy, M.J. Zabik, 1992(Prepublication), A Field Evaluation of Equilibrium Partitioning in the Grand Calumet River, and Indiana Harbor Karickoff, S.W., D.S. Brown, T.A. Scott, "Sorption of Hydrophobic Pollutants on Natural Seidments", Water Research, 13, 1979, pp 241-248 Karickoff, S.W., "Semi-Emperical Estimation of Sorption of Hydrophobic Pollutants on Natural Sediments and Soils, Chemosphere, 10 1981 pp 833-846 Karickoff, S.W., "Sorption Kinetics of Hydrophobic Pollutants in Natural Sediments", Contaminants and Sediments, Vol. 2, Ann Arbor Science Publishers, Inc., Ann Arbor MI, 1980, pp 193- 205 Lake, J.L., N.I. rubinstein, H. Lee 11, CA. Lake, J. Heishe, Spavibnano,l990, Equilibrium Partitioning and Bioaccumulation of Sediment associated Contaminants by Infaunal Organisms, Environ. Toxicol. Chem 9: 1095-1106 120 Lambert, S. M., (1967), Functional Relationship Between Sorption in Soil and Chemical Structure, LAW" 15, 572- 576. Lambert, S.M., (1968), Omega, A Useful Index of Soil Sorption Equilibria, J. Agric. Fd. Chem., 16, 340-343. Lambert, s.M., (1966) the influence of soil Moisture on Herbicidal Response, Weeds, 14, 273-275. Landrum, P.F., Giesy, J.P., "Advances in Identification and Analysis of Organic Pollutants in Water”, Keith L. H., Ed., Ann Arbor Science: Ann Arbor, MI, 1981, I, pp 345-355 Landrum, P.F., S.R. Nihart, B.J. Eadie, W.S. Gardner, 1984, Reverse Phase Seperation Method for Determing Pollutant Binding to Aldrich Humic Acid and Dissolved Organic Carbon of Natural Waters, Environ Sci. Technol, 18, 187-192 Magee, B.R., L.W. Lion and A.T. Lemley (1991), Transport of Dissolved Organic Macromolecules and Their Effect on Transport of Phenanthrene in Porous Media, Environ. Sci. Technol., 25, 323- 331. McCarthy, J.F., (1983), Role of Particulate Organic Matter in Decreasing Accumulation of Polynuclear Aromatic Hydrocarbons by Daphnia magna, Arch. Environ. Contam. Toxicol. 12, 559-568 (1983). McCarthy, J.F., J.M. Zachara, (1989), Subsurface Transport of Contaminants, Environ. Sci. Technol., 23, 496-502. McCarthy, J.G., B.D. Jimenez, (1985), Interactions between Polycyclic Aromatic Hydrocarbons and Dissolved Humic Material: Binding and Dissociation, Environ. Sci. Technol., 19, 1072-1076. McKay D., A. Bobra, W.Y. shiu, Relationships Between Aqueous Solubility and Octanol-Water Partitioning Coefficients, Chemosphere, 9 1980 pp 701-711 Means, J.C., S.G. Wood, J.J. Hassett, W.L. Banwart, (1980), Sorption of Polynuclear Aromatic Hydrocarbons by Sediments and Soils, Environ. Sci. Technol., 14, 1524-1528. 121 Morra, M. J.; M.O. Corapcioglu, P.M.A. von Wandruska, D.B. marshall, and K. Topper, (1990), Fluorescence Quenching and Polarization Studies of Naphthalene and l Napthol Interaction with Humic Acid, Soil. Sci. Soc. Am. J., 54, 1283-1288. Murphy, E.M., J.M. Zachara, S.C. Smith, 1990, Influence of Mineral Bound Humic Substances on the Sorption of Hydrophobic Organic Compounds, Environ. Sci. Technol., 24, 1507-1516 O'Connor DJ. and LP. Connolly, 1980, The effect of concentration of Absorbing Solids on the Partition Coefficient, Water Resources 14, 1517-1523. Slautman, M., Mineral Surfaces and Humic Substances: Partitioning of Hydrophobic Organic Pollutants, PhD Thesis, 1992 MW. 1981. IN. Miller. Chapman Hall, New York .10.. trio! 0 '1' 5|! 0 11' .10 1.. (1990) Swarzenbach, R.P., J. Westall, Transport of Nonpolar Organic Compounds from Surface Water to Groundwater, Laboratory Sorption Studies, Environ. Sci. Technol., 15, # 11, 1360 - 1367. Voice, T.C., C.P. Rice and W.J. Weber Jr. (1983), Effect of Solids Concentration on the Sorptive Partitioning of Hydrophobic Pollutants in Aquatic Systems, Environ. Sci. Technol., 12, 513- 518. Voice, T.C., W.J. Weber, Jr., (1985), Sorbent Concentration Effects in Liquid/Solid Partitioning, Environ. Sci. Technol., 19, 789-796. Weber, W.J. Jr., T.C. Voice, A. Jodellah, (1983), Adsorption of Humic Substances: The Effects of Heterogeneity and System Characteristics, J.AWWA, Dec., 612-619. APPENDICIES APPENDIX A: Fluorescence Quenching Appendix 1: Fluorescence Quenching Stern-Volmer Equation and Correction Coefficient Stern-Volmer Equation PAH + DOM = [PAH-DOM] complex Defining, Fo -- Fluorescence in absence of quencher F = Fluorescence in presence of quencher Kdoc- [PAH-DOM] ex/{IPAHHDOMJ} compl and assuming [PAH] 1001/ [PAH] free = Fo/F Mass balance on the PAH, [PAH] total= [PAH] free + [PAH] bound Dividing by [PAH1m. [PAH] t‘ml/ [PAH] he: 1+[PAH] bound/ [PAH] he: [DOM] / [DOM] [PAIHtotal/[PAmfree = 1 + KdochM] . Substituting to obtain the form of the Stern Volmer plot, Fo/F = 1 + Kdoc[DOM] Q . : tfi‘ t Fo = on: I= Io*10 "*1 Beer Iambert law I0 = intensity of excitation at sample surface 122 A = Absorbance per cm pathlength at relative wavelength d = depth in cm of nominal path length of excitation If F = c*I F = Fo*10’Ad, C= Fo/F = 10“ For emrnission absorbance, C=10(Ad+A'd') The assumptions for this derivation include the following: Optical pathlength can be defined Finite widths of beams is ignored Reflection is insignificant Bandwidth of light is infinitely small Since F is porportional to light absorbed between d1 and d2 'Ad 1 - 'AdZ) F = Ky( 10 10 As A approaches 0, F approaches F0 and d1 and d2 are approximated by the first term in series expansion. Fo = Ky‘2.3f"A*(d2-d,) c = 2.3*A*(d,-d,)/(1o-Ml-ro-W) 123 Benzo-a-pyrene Timed Fluorescence Data 1W: PE FLYO MOD: sun-a Tm: SPECTMU W 0: 1111895141.?!» 00- 7m: BINARY We 10: FLO“ (V2.00) M Clan-0: 00:07:07. I“ LII 1100000; 0097317. 02101‘2 OI- 001 1 xtssq Y (WT) 10 20 00 00 70 100 120 120 100 100 100 100 210 220 200 200 270 200 200 210 220 200 270 200 000 020 020 000 000 000 000 010 020 000 000 070 000 000 010 020 000 070 000 700 720 720 700 700 700 700 010 020 000 000 070 000 000 010 020 000 070 000 1000 1020 1020 1000 1000 1000 1000 1110 1120 1100 1100 1170 1100 1200 120.020 110.007 120.120 120.200 120.200 120.222 120.200 120.217 120.100 110.002 110.070 120.002 120.100 120.200 120.201 120.002 120.001 120.112 120.20 120.207 120.020 110.002 110.070 120.000 110.002 110.002 110.702 110.700 110.002 120.000 120.020 110.000 110.020 120.000 120.00 110.002 110.02 110.002 110.000 110.070 110.01 110.012 110.020 110.002 110.002 110.07 110.012 110.702 110.000 110.070 110.071 110.071 110.702 110.020 110.700 110.011 110.712 110.001 110.700 110.722 110.700 110.000 110.020 110.00 110.700 110.72 110.000 110.000 110.010 110.070 110.017 110.020 110.020 110.000 110.272 110.200 110.02 110.021 110.220 110.000 WEBEHLMO 124 7W: Mu: Sun-a 1m: PE ETD SPECTRA! W D: DUEBENIJUP On 190: NW Sal-c010: PLDMMJO) m Clubd’: 00:07:07. am LII 1100000; @9717. 021022 Oat-out I559 10 20 00 00 70 00 100 120 120 100 100 100 100 210 220 200 200 270 200 200 210 220 200 200 270 200 000 020 020 000 000 000 000 010 020 000 000 070 000 000 010 020 000 070 000 700 720 720 700 700 700 700 010 020 000 000 070 000 000 010 020 000 000 070 000 1000 1020 1020 1000 1000 1000 1000 1110 1120 1100 1100 1170 1100 1200 VP") 120.020 110.007 120.120 120.200 120.200 120.222 120.200 120.217 120.100 110.002 1 10.070 120.002 120.100 120.200 120.201 120.002 120.001 .110.000 120.112 120.20 120.207 120.020 110.002 110.070 120.000 110.002 110.002 110.702 110.700 110.002 120.000 120.020 110.000 110.020 120.000 120.00 110.002 110.02 110.002 110.000 110.070 110.01 110.012 110.020 110.002 110.002 110.07 110.012 110.702 110.000 110.070 110.071 110.071 110.702 110.020 110.700 110.011 110.712 110.001 110.700 110.722 110.700 110.000 110.020 110.00 110.700 110.72 110.000 110.000 110.010 110.070 110.017 110.020 110.020 110.000 110.272 110.200 110.02 110.021 110.220 110.000 TNEBENLWKI 124 1W: Mu: Sum-at 1m: PE FLTO ”EON“ w & TWEBEDQJHP M111»: 01W my. 10: m (450) MIL 0"“: 00:00:10. am LII 1100000: 00:00:10. mom Duo-t1 “SEQ 10 20 00 00 70 00 100 120 120 100 100 100 100 210 220 200 200 270 200 200 210 220 200 200 270 200 000 020 020 000 000 000 000 010 020 000 070 000 010 020 000 000 070 000 700 720 720 700 700 700 700 010 020 000 000 070 000 000 010 020 000 070 000 1000 1020 1020 1000 1000 1000 1000 1110 1120 1100 1100 1170 1100 1200 Your) 100.007 100.210 100.020 100.200 100.270 100.002 100.270 100.000 100.010 100.022 100.000 100.727 100.100 100.200 102.070 102.007 102.000 102.070 102.002 102.200 102.200 102.000 102.020 102.221 102.20 102.027 102.202 102.220 102.000 102.000 102.100 102.120 102.10 102.211 102.210 102.100 102.201 102.200 102.12 102.020 102.002 102.201 102.200 102.122 102.000 101.002 101.700 101.722 101.202 101.112 100.000 100.070 100.021 100.200 100.212 100.000 100.101 100.000 100.002 100.100 100.220 100.022 100.07 100.220 100.002 100.021 100.001 100.000 100.007 100.000 100.007 100.011 100.000 100.200 100.010 100.027 100.00 100.200 100.200 100.002 100.020 7101585121100 125. 1m: w u TIMEBEMJHP 01-1790: 03W swan D: m MJO) km Clo-9‘: 00:00:10. won/22 u: Heel“: 00.00:". 0mm Dan-d1 “SEQ 10 20 00 00 70 00 100 120 120 100 100 100 100 210 200 200 270 200 200 210 220 200 200 270 200 000 020 020 000 000 000 000 010 020 000 000 070 000 010 020 000 000 070 000 700 720 720 700 700 700 700 010 020 000 000 070 000 000 010 020 000 000 070 000 1000 1020 1020 1000 1000 1000 1000 1110 1120 1100 1100 1170 1100 1200 mm 100.007 100.210 100.020 100.200 100.270 100.002 100.270 100.000 100.010 100.022 100.000 100.727 100.100 100.200 102.070 102.007 102.000 102.070 102.002 102.200 102.200 102.000 102.020 102.221 102.20 102.027 102.202 102.220 102.000 102.000 102.100 102.120 102.10 102.211 102.210 102.100 102.201 102.200 102.12 102.020 102.002 102.201 102.200 102.122 102.000 101.002 101.700 101.722 101.202 101.112 100.000 100.070 100.021 100.200 100.212 100.000 100.101 100.000 100.002 100.100 100.220 100.022 100.07 100.220 100.002 100.021 100.001 100.000 100.007 100.000 100.007 100.011 100.000 100.200 100.010 100.027 100.00 100.200 100.200 100.002 100.020 WEBEIQJVKI 125. 1W: Mei-142.13: Sum-d1 TnI: PEFLTD SPECTRJH W0 IO: TIMEBEIOJHP 0"- '71»: IflHARY 5913-41410: MM”) WWW C133b0: 023230.0y02Q2 LII 34401443: 02:1220. 32mm DIN a! 1 “seq 10 20 00 00 70 00 100 120 120 100 100 100 100 210 220 200 200 270 200 200 210 220 200 200 270 200 000 020 020 000 000 000 000 010 020 000 000 070 000 000 010 020 000 000 070 000 700 720 720 700 700 700 700 010 020 000 000 070 000 000 010 020 000 000 070 000 1000 1020 1020 1000 1000 1000 1000 1110 1120 1100 1100 1170 1100 1200 71"") 244.333 245.445 234.444 244.334 245.331 234.374 244.571 244.331 244.143 244.134 243.344 243.472 243.741 243.511 243.423 233.532 243.444 243.213 243.237 242.332 242.541 242.443 242.523 242.431 242.151 231.34 242.213 242.334 241.754 201.10 243.343 243.437 243.211 273.434 273.343 273.334 273.433 273.553 274.354 274.421 274.424 274.232 273.134 277.735 277.414 277.322 277.335 277.353 277.337 277.144 277.344 274.343 274.573 274.233 274.343 274.151 274.234 274.231 274.221 274.227 274.342 275.444 275.731 275.543 275.432 275.253 275.374 275.332 275.33 275.317 274.442 275.257 275.144 275.133 274.357 274.743 274.343 "270.007 270.000 270.000 270.000 WEBEFQVIKI 126 Typo: PE FLTD W4 ID. TIUEBEMJUP 0413 7,143: BINARY 3.1-... 10: non n53) Andra: 034144: 02:40.04. 32mm LI“ “00030: 02:40.04. 3mm MHI 1(SEC) I0 00 40 00 70 00 100 I20 I00 I00 I00 I00 I00 2I0 220 240 200 270 200 000 0I0 000 040 000 070 000 400 420 400 400 400 400 400 0I0 020 040 000 070 000 000 0I0 000 040 000 070 000 700 720 700 700 700 700 700 0I0 020 040 000 070 000 000 0I0 000 040 000 070 000 I000 I020 I000 I000 1000 I000 1000 IIIO II20 II40 II00 II70 II00 I200 VP”) 40I.002 402.244 402.000 400307 400.020 400.044 400J00 400.000 404.I24 404.000 404.704 404.700 404.202 400.00I 404.I00 404.0I7 404.000 400M042 400.I04 404.770 404.0I7 404.00I 404.00 404.777 404.020 404.0II 404.0II 404.407 404.020 404.04 404AIO 404.200 404.40 404.000 404.0I0 404.070 404.070 404JIO 404.002 404.404 404.00I 404.0I7 404.000 404.I00 404.24I 404.000 404.I02 404.002 404.I47 400.020 400.040 404.040 404.000 404.I00 404.40 404.004 404.0 404.470 404.200 404.I40 404.20I 404.000 404.004 404.200 404.I24 404.IIO 404.02 404.4I2 404.020 404.000 404.I7 400.720 400.02I 400.000 400.7I0 404.002 404.20 404.000 404.00 404.000 400.000 THJEBEN4VVKI 127 1W: Mon: 040.501 In»: PE FLYD SPECTRJU W0 IQ “US$06.11” o«-1744: 004M? 0313-3130: 41014 «2.53) MI. 03350: 002190. 3m LII 1143144. 002190. 021003 DIIIKI 01583 10 00 40 00 70 00 100 120 100 I00 100 100 100 210 220 240 200 270 200 000 010 000 040 000 ' 070 000 400 420 400 400 400 400 400 010 020 040 000 070 000 000 010 000 040 000 070 000 700 720 700 700 700 700 700 010 020 040 000 070 000 000 010 000 040 000 070 000 1000 1020 1000 1000 1000 1000 1000 1110 1120 1140 1100 1170 1100 1200 71"“) 000.010 000.047 000.770 000.14 000.020 000.271 000.010 007.470 000.102 000.140 007420 000.24 000.774 000.001 000110 000.001 000.000 004.704 000.100 000.400 000.00 000.042 000.100 000.027 000.000 004.010 004.020 004.001 000.201 000.400 000.040 004.004 004.700 004.072 004.702 004.420 004.022 000.040 000.000 000.00 004.000 004.470 004.00 004.102 000.70 000.400 000.000 000.011 002.770 002.022 000.010 000.271 000.000 000.401 000.270 000.02 002.001 000.070 000.104 000.004 002.000 002.07 002.070 001.004 002.01 1 002.020 001.000 001.000 001.00 001.700 001.000 001.402 001.000 001.014 001.427 001.00 001.20 001.040 001.407 001.207 000.000 WEBEhéml 128 134233.33: PE ETD 330133713”: 51.313371 1173: “CTN“ W 10. 1144606710314? 0333 1133: BINARY 0373-373 10: RD“ ((2.50) 471-7744. 0441.3: 33.47:". 321mm L441 14431144; 3347:14. own: 0413 331 1 11583) Y (M) 3 351.334 15 351.455 33 351.345 45 351.451 43 351.333 73 333.725 33 353.514 135 353.431 123 353.734 135 353.331 153 353.752 145 353.44 133 303.435 134 353.514 213 353.453 225 353.322 243 353.423 253 353.542 273 353.334 235 343.342 333 343.733 310 343.471 333 343.434 345 353.114 343 353.137 375 353.341 333 343.313 435 353.324 423 353.247 435 353.313 453 353.345 445 343.772 433 353.343 435 353.325 513 343.354 525 343.741 543 343.714 555 343.453 573 343.574 545 343.535 433 343.445 415 343.4 433 343.447 445 343.13 443 344.375 375 344.33 433 344.754 735 343.35 723 343.374 735 343.214 753 343.24 740 343.377 743 343.334 735 343.312 313 344.751 323 343.533 343 343.444 355 344.543 473 344.431 435 344.471 433 343.234 315 343.373 333 347.733 345 347.533 343 347.774 370 343.121 333 344.237 1335 347.322 1323 347.434 1335 347.533 1353 343.331 1345 344.335 1333 347.735 1335 347.53 1113 347.342 1125 347.153 1143 347.42 1155 347.772 1173 347.341 1145 347.331 1233 347.443 “HEBEMNfKI 129 130v33n: 8333303393: 5303461 In»: PE ETD SPECTRJU W U. TIUEBEWJ'HP 0314 11113: BINARY 5373-473 D; FLO“ 90.50) Andri: 0338‘: 0421290, 0210012 L31 1408034: 0431200, IMJfl 0313341 0155C) 15 33 45 53 75 30 135 120 100 153 145 133 135 210 225 243 255 273 235 333 315 330 340 330 375 330 435 423 435 453 445 430 435 013 525 543 555 573 530 030 315 503 445 030 475 003 735 723 705 753 745 733 735 413 325 343 455 370 445 000 315 030 345 000 375 000 1330 1320 1335 1353 1345 1333 1300 1113 1120 1140 1155 1170 1145 1233 *0”) 020.7 020.014 020.07 020A00 020.024 020.110 020.007 020.000 020.040 020.000 020.004 020.720 020.000 020.40 020.002 020020 020.717 020.000 020.000 020.040 020.000 020.014 020.240 024.700 024.404 024.44 024102 024.044 020.00 020.14 024.721 024.001 024.007 024.400 024.201 024.441 024.000 024.420 024.070 024.000 024.002 024.10 020J71 020.720 020100 024.200 024.110 020.004 020.004 020.700 020.001 020.001 020.021 020.010 020.010 020.004 020500 020J00 020.000 020.700 020.020 020.220 022.001 020.021 020.242 020.400 020.00 020.100 022J07 022.001 020.220 020.10 020.177 020.002 022.000 022.042 022.000 020.001 020.10 022.040 022.000 THJEBENIVWKI 130 1m: PE F'LTO 313-nevi": mm 1173: SPECTRA! W D: “BEBE H.714? Dc- Typo: BINARY Soft-n IO: FLO“ (V2.00) C134“: 04:0491. 42mm LII “M30: 0434.01. 42mm Dunn 0155C) 10 00 40 00 70 00 100 120 100 100 100 100 100 210 220 240 200 270 200 000 010 000 040 000 070 000 400 420 400 400 400 400 400 010 020 040 000 070 000 000 010 000 040 000 070 000 700 720 700 700 700 700 700 010 020 040 000 070 000 000 010 000 040 000 070 000 1000 1020 1000 1000 1000 1000 1000 1110 1120 1140 1100 1170 1100 1200 71”") 000.477 000.000 000.000 000.101 000.000 004.714 004.000 000.007 000.400 000.401 000.20 002.000 002.000 001.040 002.100 002.000 000.001 000.001 002.000 002.070 002.470 002.047 002.004 002.740 002.010 000.004 000.210 002.072 002.000 000.000 000.020 000.120 000.204 002.701 002.020 002.402 002.000 002.722 002.701 0020 002.000 002.002 001.000 001.010 001.17 001.000 001.010 000.700 000.017 000.001 001.27 001.212 000.001 001.007 001.200 000.01 000.100 000.274 000.722 000.711 000.040 000.070 000.022 000.000 000.041 000.000 000.100 000.210 000J040 000.000 000.100 000.120 000.000 000.000 000.000 000.071 000.227 000.000 000.710 000.000 000.000 TNEBENAWKI '131 1m: W IQ TIMEOEHJUP 04- Mo: BINARY 0309-3 10: RD“ V2.00) m Clubdt 00.00.02. cm L”! “$030: 009492. 0210M 04100311 X15831 10 00 40 00 70 00 100 120 100 100 100 100 100 210 220 240 200 270 200 000 010 000 040 000 070 000 400 420 400 400 400 400 400 010 020 040 000 070 000 000 010 000 040 000 070 000 700 720 700 700 700 700 700 010 020 040 000 070 000 000 010 000 040 000 070 000 1000 1020 1000 1000 1000 1000 1000 1110 1120 1140 1100 1170 1100 1200 Hum 040.042 040100 040.001 044.00 044.274 044.022 044.000 044.20 040.021 040.002 040.004 040.700 040.070 040.000 040.707 040.02 040.2 040.102 040.110 042.024 042.700 042.004 040.107 040.007 042.710 042.010 042.004 042.040 042.101 042.270 041.070 041.000 042.070 042.402 042.00 042.04 042.000 042.104 042.100 042.101 041.700 041.070 041.020 042.040 042.070 041.040 041.01 041.002 042.100 042.007 041.700 041.00 041.700 041.004 041.047 041.000 041.020 042.000 042.200 042.121 041.020 041.200 041.200 041.040 041.001 042.000 042.022 041.400 041.000 041.222 041.471 041.040 041.410 041.707 041.000 041.100 041.000 041.100 040.000 041.000 041.244 TNEBEMMIKI 132 1nd": mm”: Sum-ct Two: PE FLTO VGCTRJH w D: 711109410114? 04‘7"”: BINARY sour-nu. noun”) m Clu- 4: 0421000. 32mm Lu 11941434: 0421454. 112/om DIIM1 "SEQ 10 00 40 00 70 00 100 120 100 100 100 100 100 210 220 240 200 270 200 000 010 000 000 070 000 400 420 400 400 400 400 400 010 020 000 070 000 000 010 000 040 000 070 000 700 720 700 700 700 700 700 010 020 040 000 070 000 000 010 000 040 000 070 000 1000 1020 1000 1000 1000 1000 1000 1110 1120 1140 1100 1170 1100 1200 V out) 101.022 101.047 102.041 102.147 102.200 102.404 102.001 102.000 102.704 100.001 100.270 100.000 100.702 100.701 100.421 100.017 102.740 102.07 102.027 102.102 101.000 102.002 102.124 102.107 102.000 102.000 102.001 102.040 102.200 101.041 102.104 102.207 102.200 102.011 102.204 102.102 102.007 101.000 101.002 101.000 101.004 101.700 102.010 101.007 101.021 101.721 101.010 101.001 101.000 101.710 101.000 101.072 101.001 101.400 101.01 101.007 101.070 101.00 101.477 101.041 101.701 101.707 101.002 101.704 101.000 101.000 101.740 102.004 102.107 101.000 101.001 101.070 101.700 101.007 102.011 101.004 101.041 101.004 101.047 101.070 101.002 7114057410.le 133 1w": PE FUD mm": sum-ch typo: syscmuu W 10: nuaem LN? 00' 13'": DNA!" SUI-m 10: FLDU 04.00) W: Oubdz “1000. 02mm L441 04061000: 00:40.00. 02100‘8 D‘- M 1 X1583) Y (”‘71 0 040.041 10 040.420 00 040.400 40 040.401 00 040.001 70 040.002 00 040.100 100 040.011 120 040.710 100 040.440 100 040.070 100 040.000 100 040.404 100 040.004 210 047.0 220 047.001 240 047.010 200 047.00 270 047.002 200 047.74 000 047.004 010 047.200 000 047.272 040 047.010 000 047.102 070 040.000 000 040.704 400 040.074 420 040.400 400 040.020 400 040.01 400 040.70 400 040.000 400 040.400 010 040.000 020 040.007 040 040.200 000 040.021 070 040.72 000 040.771 000 040.040 010 047.040 000 040.040 040 040.00 000 040.004 070 040.400 000 040.400 700 040.404 720 040.000 700 040.400 700 040.010 700 044.00 700 040.40 700 040.4 010 040.200 020 040.110 040 040.107 000 040.000 070 040.200 000 040.110 000 040.120 010 040.207 . 000 040.000 040 040.100 000 040.007 070 040.070 000 040.012 1000 040.000 1020 040.01 1000 040.000 1000 040.02 1000 040.000 1000 040.004 1000 040.000 1110 040.410 1120 040.404 1140 040.010 1100 040.120 1170 044.004 1100 044.000 1200 044.070 “1185141113410 134 Tm: PE FLTD sumo to: 'nuaemz‘mr 04!: 7pc: 01W son-co ID: ED“ M00) Mam. Can-4: 0711097. om LII 0400000: 07:1097. swam Dlhtdl X(SEC) 10 40 00 70 00 100 120 100 100 100 100 100 210 220 240 200 270 200 000 010 1 000 040 000 070 000 400 420 400 400 400 400 400 010 020 040 050 070 000 000 010 000 040 000 070 000 700 720 700 700 700 700 700 010 020 040 000 070 000 000 010 000 040 000 070 000 1000 1020 1000 1000 1000 1000 1000 1110 1120 1140 1100 1170 1100 1200 V out) 200.000 100.071 200.007 200.700 200.010 100.007 100.000 100.707 200.100 200.101 100.207 100.702 100.077 10010 200.000 200J00 200J47 100.011 100.000 100.0 100.020 100100 100.012 100.170 100.200 100.004 100.010 100.20 100.400 100.120 107.770 107.007 107.001 107.007 107.007 107.042 107.401 107.000 107.700 107.070 107.040 107.000 100.12 100.21 100.127 100.020 100.021 107.070 107.744 107.00 107.007 107.200 107.007 107.001 107.011 107.201 107.200 107.000 107.001 107.040 107.211 107.000 107.000 107.241 107.20 107.000 107.02 107.002 107.102 107.12 107.047 107.02 107.00 107.004 107.144 10L00 107.001 100.720 100.040 100.041 100.700 “USEN12.WK1 135 7pc: W1 10: “BERNIE? cum-1191: 01W saw. to: H.011 n10) Annfifit C11 18‘: 07:00:11, 1210322 L001 11mm 07:10:11. 02100fl OIIMI useq 10 00 40 00 70 00 100 120 100 100 100 100 100 210 220 240 200 270 200 000 010 000 040 000 070 000 400 420 400 400 400 400 400 010 020 040 000 070 000 000 010 000 040 000 070 000 700 720 700 700 700 700 700 010 020 040 000 070 000 000 010 000 040 000 070 000 1000 1020 1000 1000 1000 1000 1000 1110 1120 1140 1100 1170 1100 1200 '0’") 111.111 117.111 117.111 117.117 117.011 117.017 117.121 107.170 111.711 111.111 117.11 117.177 111.111 111.122 117.111 117.11 117.117 117.11 117.211 117.271 111.112 111.111 111.211 111.111 111.211 111.111 117.111 100.71 111.111 111.111 117.111 111.701 111.311 111.111 111.111 111.112 111.171 111.111 111.111 111.121 111.111 111.111 111.111 105.011 111.111 111.111 111.111 111.110 111.112 111.111 111.127 111.711 111.121 100.740 111.121 111.111 111.127 111.11 111.121 111.111 111.121 100.021 111.117 111.111 111.111 100.004 100.000 111.11: 111.11 111.111 111.121 111.111 111.111 111.111 111.111 111.121 111.111 111.117 111.121 111.111 111.117 “11851111le 136 7'0“": PE FLTO Mu: Sun-d1 1m: SPECTKJH $111911 10: 1111001117111! 0111 7,111: EMMY 00101111 10: RD“ (V2.00) Mum: 011.11; 111112. 02”“ [J11 11.11111; 11.1112. 1271222 0111 111 1 1118:) Y MT) 1 211.11 11 212.171 21 212.111 11 212.17 11 212.711 71 212.111 11 212.111 111 212.21 121 212.212 121 212.22 111 212.111 111 212.211 111 212.121 111 212.121 211 212.221 221 212.111 211 211.111 211 211.111 271 211.712 211 211.111 211 ‘ 211.211 211 ‘ 211.111 221 211.112 211 211.111 211 211.112 271 211.21 211 211.111 111 211.121 121 211.172 121 211.117 111 211.112 111 211.111 111 211.172 111 211.111 111 211.172 121 211.127 111 211.11 111 211.112 171 211.117 111 211.171 111 211.111 111 211.111 121 211.772 111 211.121 111 211.11 171 211.111 111 211.172 711 211.121 721 211.112 721 211.117 711 211.211 711 211.111 711 211.111 711 211.111 111 211.12 121 211.121 111 211.111 111 211.12 171 211.117 111 211.711 111 211.111 111 211.111 121 211.111 111 211.112 111 210.751 171 211.112 111 211.121 1111 211.111 1121 211.112 1121 211.111 1111 211.212 1111 211.221 1111 211.112 1111 211.727 1111 211.111 1121 211.172 1111 211.711 1111 211.11 1171 211.22 1111 211.111 1211 211.711 “BEEN“.WKI 137 11069.11: 3111-1111": 1111-111 7m: 05 FLYO SPECTRA] W ID: “USENUJMP 01- 7,91: HWY 31111-1710: RD“ 0450) Mum: 011.0: 0022217. 1mm LII 0400010: 0022217. 021023 “III-(I MW 405 510 525 540 555 570 505 000 015 020 000 075 000 705 720 725 750 705 700 705 010 025 055 070 005 000 015 020 045 000 075 000 I005 I020 I025 0050 1005 1000 I005 II00 1025 1140 1055 1170 1105 1200 YMT) 500.20 400.04 400.204 400.500 400.427 400.002 400.550 400.075 407.524 407.210 407.407 407.000 407.770 407.400 400.000 400.247 400.545 400.54 400.2 I2 400.020 405.007 405.772 405.027 405.022 405.720 405.072 400.202 405.057 405.721 405.040 405.440 405.2 [2 405.405 405.040 400.2 400.024 405.022 405.222 405.210 405.227 405.242 405.201 405.407 404.025 404.402 404.022 405.770 405.204 405.227 405.024 404.015 405.122 404.775 404.240 404.405 405.074 405.450 405.242 404.745 404.500 404.20 404.42! 404.00 404.022 404.22 404.050 404.120 404.240 404.255 404.100 404.025 404.051 402.072 404.025 402.001 402.705 402.517 402.404 402.447 402.200 402.” 138 “MBENWAVKI 00:45:42, 0M 04:45:42, 1mm 111101.11: PE 1170 1.111-cup: 1.111-a1 Tm: mama W1 10: 111185711ka 0111 1,91: BINARY 210-171 10: RD“ 0450) Ma: 011110: U11 1110114: 0111 111 1 1111111 15 20 45 00 75 00 105 120 125 150 I05 100 105 210 225 240 255 270 205 200 215 220 245 200 275 200 405 420 425 450 405 400 405 510 525 540 055 570 505 000 015 020 045 000 075 000 705 720 725 750 705 700 705 010 025 040 055 070 005 000 015 020 045 000 075 000 1005 1020 1025 1050 1005 1000 1005 1110 1125 1140 1155 1170 1105 1200 520.000 520.242 527.22I 520.051 025J5 525014 524.005 524.425 524.10! 522170 522.025 522.055 022.010 522.400 522.102 522.240 022.20 522.201 521.000 52L701 522.15 522.102 52L200 521.15 521.042 521.021 521.170 521.022 521.270 521.274 520.074 521.001 521.244 021.024 521.200 521.050 521.422 521.502 521.40 020.717 520.202 520.055 520.702 520.770 521.022 521.102 520.040 520.750 520.040 521.005 , 521.050 020.002 520.005 520.222 020.274 520J10 020.040 521.214 521.520 521.240 520.700 520.500 520.542 520.757 521.220 521.100 520.052 521.501 021.042 521.575 521.22 521.212 521.524 021.520 521.104 520.700 521.150 521.25 521.074 521.200 521.021 TIUBENII.WK1 139 7W: Mann: Snot-as Tran: PE R70 SPECTRA! w. 10: 711-189410.711? 04h 7m: UNAHY 2a.." 10: ADM V2.50) w. 0441-0: 00.00110, 02M LII 010G100; 00.00210. 0mm 04140011 1155C) 10 20 45 00 75 00 105 120 125 150 105 100 105 210 225 240 255 270 205 200 215 220 245 200 275 200 405 420 425 450 405 400 405 510 525 540 550 570 505 000 015 020 040 000 075 000 705 720 725 750 705 700 705 010 025 040 055 070 005 000 015 020 045 000 075 000 1005 1020 1025 1050 1005 1000 1005 1110 1125 1140 1155 1170 1145 1200 YONT) 407.201 400.205 405.212 405.170 405.075 404.550 404.242 404.045 404.045 404.007 404.102 402.515 402.074 402.000 402.154 402.040 402.22 401.744 401.220 401.247 ' 441.427 401.404 401.070 401.107 401.77 401.020 401.002 402.202 402.057 402.207 402324 402.500 402J02 402157 402.014 402.005 402.124 401.500 401.020 401J41 401175 401.210 401.070 402.202 402A01 492.100 401.040 402.077 402.220 402.201 402.01 402.101 402.224 402.020 402J00 402.015 402.020 401.722 411 401.102 401.270 401.104 401.270 401.402 401.440 401.00 491.000 401.011 402.227 402.002 401.000 40L02 401.022 401.022 442.42 442.457 402.000 402.14 491.051 402.044 402.020 “1189110 WKI 140 APPENDIX B: Instrument Specifications APPENDIX B: Instrument Specifications Instrument Specifications I. Fluorimeter Instrument: Perkin Elmer LS 50 Spectrafluorimeter Source: Zenon Arc Lamp Phenanthrene B-a—P Excitation Wavelength 255 nm 380 nm Emmission Wavelength 365 nm 445 nm Excitation Slit 5 nm 15 nm Emmission Slit 5 nm 15 nm Time Drive - 20 minutes Frequency - 15 seconds II. Total Organic Carbon Analyzer Instrument: Shimadzu Total Organic Carbon Analyzer Catalyst: Low Sensitivity Acid Purge: 5 minutes at pH of 3 Sensitivity: 10x 141 III. High Performance liquid Chromatography Instrument: Gilson HPLC Column: C1 8, reverse phase Mobile Phase: 1 minute, 50% acetonitrile, 50% water Ramp to 100% acetonitrile ' 8 minutes, 100% acetonitrile 15 minutes, 50% acetonitrile, 50% water ' 16 minutes, end Flow Rate: 2.5 nil/minute Dectector: UV 116, 0.01 AUFS Injection Vol.: 20 ul IV. Liquid Scintillation Counting Instrument: Beckman LS Counter Time: 10 minutes Region a: LL-UL 0.0-12.0 Region b: LL-UL 12.0-156.0 QIP : tsie/AIC Conventional DPM 142 APPENDIX C: Key to Tables 2.2 through 2.6 APPENDIX C: Key to Tables 2.2 through 2.6 Key to Tables 2.2 through 2.6 Column 1 2 Definition Sample identification Grams of sediment (freeze dried) placed in 25 m1 centrifuge tube Grams of Dl/RO water placed in 25 ml centrifuge tubes. Concentration of sediment ln 25 ml centrifuge tubes in mg/l. Calculated as (column Z/column 3) x 105 Amount of radiolabelled compound placed in the 25 m1 centrifuge tube from stock solution, in discharge per minute (dpm). . 6 Absorbance of supernatant in 25 ml centrifuge tube after equilibrium. 7 Grams of supernatant used for a liquid phase 14C activity count. 8 14C activity in liquid portion , in dpm. 9 14C activity in liquid phase, in dpm/l. (Column 8)/ (Column 7) 10 ml of methylene chloride used to extract the 14C activity in the sediments. 1 1 14C activity in the sediments, in dpm. 12 14C activity in the sediments in dpm/ kg. (column 1 1)/(column2)x1000x’l‘0TAL MECLz/Sample Volume MECLZ. 13 14C activity extracted from the glass tube, in dpm. 14 [(Column 8) x (Column 3)/(Column 7) + (Column 11) + (Column 13)]/ (Column 5) 15 (Column 12)/ (Column 14) 16 (Column 12)/(Colu=ma 9)/foc; where foc‘ 5% 17 (Column 15)/ (Column 9)/foc; where foc" 5% 143 APPENDIX D: Modelling Data BaP Nonlinear data Non-linear Parameter Estimation BAP BAP Total Estimated Koc BAP solutions Reverse Phase Reverse Phase DPM/1 UsinLNonlinear Estimated Adjusted aqueous K1. and K2 estimates Koc DOC, mgli Free, bdpmll Kdoc Solids. rug/1 212626.358 5.02220355 226662.074 50328.4126 293076.923 105881.371 1462.45059 153634.694 7.5885197 117462.909 79460.8657 200591.716 95104.239 3308.03036 81193.0803 11.5353651 127411.169 27884.7344 190737.24 95210.7293 7255.36993 562407795 17.: 823911 102566.539 20504.7512 163915.547 90109.0009 13324.0446 53643.4925 25.7424683 57082.7415 20924.1459 98461.5385 91439.7799 25608.7824 72894.3311 14.366444 79856.4314 45173.124 149139.579 88755.0017 10035.8566 69935.2324 14.2275727 145643.656 64391.3966 298301.887 90428.7712 9875.9209 550432205" 14.1989641 273245.361 31898.0271 438811.881 94326.6002 9843.07572 83187.4284 14.4011358 463689.32 10075.9392 48374.2807 14.294134 507808.21 25269.1998 832035.398 88376.0358 9952.47525 60152.9608 14.2566202 492397.957 43941.6021 965354.331 83711.9825 9909.30599 163587.012 8.53721139 97145.6415 74614.8012 166730.402 96071.296 4102.35906 130418.497 8.43872069 329133.858 4017.36385 115003.546 8.57680758 329190.276 43311.5847 507976.654 94323.0636 4136.69065 140033.894 8.42954099 627800 4009.47119 139451.623 8.38274681 366038.183 82094.7582 698148.148 88403.7046 3969.3155 45399.6482 22.4804 786 64370.2692 28037.258 136039.604 77788.597 20684.4409 35878.4849 22.3318182 209232.145 28005.7873 438195.777 78328.2052 20468.1873 33500.9646 22.1458734 507126.48 7803.74697 767039.106 86666.4786 20198.7281 42102.7622 144 1. Date: Time: 085 mmqmmari-I 24-AUG-92 14:13:13 File: SYSTAT Data Editor has 5 variables and KOC DOC 212626.358 5.022 153634.694 7.589 81193.080 11.835 56240.780 17.082 53643.493 25.742 72894.331 14.366 69935.232 14.228 65043.221 14.199 48374.281 14.294 60152.961 14.257 163587.012 8.537 115003.546 8.577 139451.623 8.383 45399.648 22.480 35878.485 22.332 22.146 33500.965 19 cases printed out of 19 cases. FREE 226662.074 117462.909 127411.169 102566.539 57082.742 79856.431 145643.656 273245.361 507808.210 492397.957 97145.641 329190.276 366038.183 64370.269 209232.145 507126.480 KDOC 50328.413 79460.866 27884.734 20504.751 20924.146 45173.124 64391.397 31898.027 25269.200 43941.602 74614.801 43311.585 82094.758 28037.258 28005.787 7803.747 19 cases in the file. 145 CT 293076.923 200591.716 190737.240 163915.547 98461.539 149139.579 298301.887 438811.881 832035.398 965354.331 166730.402 507976.654 698148.148 136039.604 438195.777 767039.106 ITERATION LOSS PARAMETER VALUES 0 0.1657391D+12 0.lOOOD+OOO.IOOOD+OO l 0.3457568D+11 0.6222D+040.3026D+04 2 0.3454619D+11 0.5925D+040.3641D+O4 3 0.3454619D+11 O.5925D+O40.3641D+04 DEPENDENT VARIABLE IS KOC MISSING DATA OR ESTIMATES REDUCED DEGREES OF FREEDOM SOURCE SUM-OF-SQUARES DF MEAN -SQUARE REGRESSION .131198E+12 2 .655990E+11 RESIDUAL .345462E+ll l4 .246758E+10 TOTAL .165744E-I-12 16 CORRECTED .420935E+ll 15 RAW R-SQUARED (l-RESIDUALfFOTAL) = 0.792 CORRECTED R-SQUARED (l RESIDUAL/CORRECTED) = 0.179 PARAMETER ESTIMATE Kl 5924.718 K2 3640.774 Koc, = CFKI + (F km AOL 'Kl Ck/c.’ in flrcousflqx ' fig, 146 APPENDIX E: Dialysis Experiment Appendix 6: Dialysis Experiment Equilibrium dialysis was studied using the technique of Carter and Suffet, 1983, to physically seperate the free and bound forms of phenanthrene in solution. Phenanthrene at 0.5 mg/ 1, or about 50 % of its aqueous solubility was placed inside and outside of a 500 molecular weight cut-off bag (Millipore). A high concentration was required since we expected a significant portion of the phenanthrene to absorb to the bag. Varying concentrations of a humic acid solution . (AldrichR) were introduced to the outside of the bag. Both the inside and outside concentrations of phenanthrene were measured over time as 14C activity. The concentration of humic acid was measured using absorbance at 255 nm. As demonstrated in Figures 1 and 2, we found that both the inside and outside concentration of phenanthrene decreased as the amount of humic acid in solution increased. The total amount of phenanthrene as determined by what is inside and outside of the bag should have remained the same. The inability to provide a complete material balance suggested that one of several things was happening: 1. A considerable amount of phenanthrene was absorbing to the dialysis bag over time and equilibrium was not achieved. 2. The measurement technique (14C activity) was being hindered by the presence of humic acid both inside and outside of the bag. 'The bag itself was not counted since it was not completely soluble in the scintillation fluid. Therefore the material balance could not be verified as in the other techniques which we tried (ie: fluorescence quenching and empore disk filtration). The data for this failed experiment is provided in the following pages. 147 Nos .82 m5 3.... 82 2.22-2 82 a: 25 no 82 $2 .32-: 82 9.2 N 5.0 82 at; .32-? wow. 39 Rio 82 $2 .32-: m? E: .. mono as 88 :24 Nos 2 am No 82 R8 548 was 8% mm; m 43m .923 means 822 .28 mmm e #2 means 858 .28 28 Bod. 2E:: :26? .23 225.36 marge 9.25555 148 oo.N mm; om... occasion"; mm; 00% mud omd — mud . ood 25.0 n «.2 £829.} . 682 u 2 Eu< 26:: @5320... 2:3 mam 5 02330 co 22:23.82 1 ooow 1 ooom WdO ocmEEmcmzd Co «3235 000? 149 oo.N om... 3:31.023 mm; co... mud omd . b - b .— F mNd . 00.0 mood n 2m m {3.9% . 3.4%.. u .2 622:0 co Eo< 2:52 9:328. 53> mam Co 023. cc 3662382 loop 1 com 1 com 1 00V 0225555 3 £335 005 'IUJ/WdCl aptsur ISO 313313.12 PHOTUMETRIC 113-11.11 >1 1 J GI 01 Q 3 8.43? 5H 4 8.612 5//2_ 5 1.093 S/fc is. 1.7213 g/O, 151 Protocol #: 9 1‘? MAY 92 20:;- Time = 10.00 Radionuclide: H3/Cl4 Region A: LL-UL= .0— 12.0 Bkg= .00 22 Sigma= Region B: LL-UL= 12.0-1Sé.0 8kg: .00 22 Sigma: Region C: LL-UL= .0- .0 Bkg= .00 QIP = tSIE/REC Conventional DPM DPMI = 200900 DPNZ = 106700 810 S4 . 115E CPHA 252A CPHB 2328 DPMl/K BENZ/K $18 1518 FLAG 1 2 nissing vials) 8 3 10.00 426.40 3.06 2720.90 1.21 .00 3399.14 58.696 343 8 3 10.00 426.90 3.06 2740.60 1.21 .00 3423.52 58.731 344 8 3 10.00 425.60 3.07 2722.30 1.21 .00 3401.37 58.514 343 426.30 3.06 2727.93 1.21 .00-3408.04 58.647 343 A 8 4 10.00 387.30 3.21 2426.30 1.28 17.31 3031.77 58.091 341 8 4 10.00 383.10 3.23 2455.80 1.28 .00 3068.40 58.562 343 8 4 10.00 379.60 3.25 2385.70 1.29 14.08 2980.45 58.380 342 383.33 3.23 2422.60 1.29 8.36’3026.86 58.345 342' A 8 5 10.00 356.70 3.35 2249.70 1.33 11.16 2808.48 58.864 346 8 5 10.00 354.50 3.36 2261.10 1.33 .93 2822.16 58.874 348 8 5 10.00 358.60 3.34 2245.60 1.33 18.47 2802.43. 59.291 348 356.60 3.35 2252.13 1.33 10.1835811.02 59.010 347 A 8 10.00 259.60 3.93 1654.70 1.55 .00 2083.00 53.197 309 8 10.00 262.40 3.90 1659.10 1.55 .00 2038.61 52.982 308 8 6 10.00 266.90 3.87 1668.00 1.55 5.57 2099.83 52.999 308 262.97 3.90 1660.60 1.55 .00 2090.48 53.059 308 A 8 7 10.00 236.00 4.12 1502.00 1.63 1.21 1875.88 58.947 345 8 7 10.00 240.80 4.08 1481.90 1.64 '22.97 1849.92 58.774 345 8 10.00 238.00 4.10 1515.00 1.62 1.24 1891.90 58.936 345 238.27 4.10 1499.63 1.63 8.47 1872.61 58.886 345 A 8 8 10.00 196.20 4.52 1203.30 1.82 14.34 1515.95 52.329 304 8 8 10.00 194.10 4.54 1212.20 1.82 3.90 1527.15 52.412 305 8 8 10.00 194.20 4.54 1224.30 1.81 .00 1543.10 52.267 304 194.83 4.53 1213.27 1.82 5.46 1528.74 52.336 2304 A 8 9 10.00 180.60 4.71 1117.20 1.89 14.88 1394.49 58.834 346 8 9 10.00 178.10 4.74 1119.80 1.89 7.19 1397.66 58.648 347 8 9 10.00 177.10 4.75 1118.50 1.89 5.17 1395.89 59.307 348 178.60 4.73 1118.50 1.89 9.07 1396.01 58.930 347 A 8 10 10.00 194.90 4.53 1160.80 1.86 29.13 1467.97 49.563 289 8 10 10.00 195.80 4.52 1178.50 1.84 22.66 1491.74 49.450 286 8 10 10.00 193.20 4.55 1167.50 1.85 20.11 1477.55 49.205 287 194.63 4.53 1168.93 1.85 23.98 1979.08 49.406 287 A 8 11 10.00 159.10 5.01 1001.20 2.00 5.68 1250.24 58.850 345 8 11 10.00 161.10 4.98 992.10 2.01 15.10 1238.45 58.276 345 8 11 10.00 160.40 4.99 986.30 2.01 15.63 1231.27 58.503 345 160.20 5.00 993.20 2.01 12.14 1239.99 58.543 345 A 8 2 10.00 167.10 4.89 1076.60 1.93 .00 1366.60 421343 237 8 12 10.00 159.90 5.00 1078.30 1.93 .00 1370.68 42.360 235 8 12 10.00 163.70 4.94 1079.30 1.93 .00 1370.61 42.228, 237 163.57 4.95 1078.07 1.93 .00 1369.28 42.311 236 A 4 ' 10.00 142.20 5.30 900.40 2.11 2.59 1124.64 58.340 344 4 10.00 152.00 5.13 901.40 2.11 29.11 1124.64 58.115 345 4 10.00 143.00 5.29 891.40 2.12 8.59 1113.27 58.76! 343 145.73 5.24 897.73 2.11 13.44 1120.85 58.405 344 A 152 Lcr= Lcr= DiviK)=1.00 DiviH)=1.00 .00 . Ci (:1 ‘716 041‘“ 9727/c0/’ 5:03 5// 04f 5.0/ 7.98 5/H 0.46 5798 star 5%2 067‘ 570? ;//z . DU 5,04 5/7 Ooi/ 5.0). 4:) Q 11 0'. J-J-J-o 14 14 14 16 16 16 7133 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 10.00 [PEA 140.20 145.50 136.10 140.60 26.00 23.40 127.60 125.67 17213.6 17333.6 17263.7 17270.3 2520 5.34 5.24 5.42 5.34 5.63 5.69 5.60 5.64 .48 .48 .48 .48 8988 1036.70 1013.60 1004.60 1018.30 803.20 805.70 798.00 802.30 111067 110890 111022 110993 2523 0P81/K npnzxu .00 1353.07 .00 1322.75 .00 1311.83 .00 1329.24 .13 1003.10 .00 1005.95 1.59) 995.50 .00 9002.10 1.96 1.99 2. 00 1.98 2.23 2.23 2.24 2.23 .19 .19 .19 .19 .00 .00 .00 .00 133739 133470 133694 133634 153 515’ 37.356 37.569 37.423 37.449 59.179 59.314 59.068 59.187 158.73 158.45 158.39 158.52 151E FLAG 196 196 196 196 345 343 344 344 1000 1003 999 1001 A E7;7/?'fi/ ‘