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MSU Is An Affirmative Action/Equal Opportunity Institution
Walla-p 1

INVESTIGATIONS INTO THE FATE OF SELECTED PESTICIDES
IN AN EXPERIMENTAL SOIL-FILLED WASTE DISPOSAL FACILITY .

BY

GAMAL ELSAYED KHEDR

A DISSERTATION

Submitted to
Michigan State University
in partial fulfillment of the requirements
for the degree of

DOCTOR OF PHILOSOPHY

Department of Entomology, Institute for Environmental Toxicology
and Pesticide Research Center

1994

ABSTRACT

INVESTIGATIONS INTO THE FATE OF SELECTED PESTICIDES
IN AN EXPERIMENTAL SOIL-FILLED WASTE DISPOSAL FACILITY

BY

GAMAL ELSAYED KHEDR

An experimental pesticides waste disposal facility at Michigan State
University located in Fennvill, Michigan was used as a demonstration
compartment for the study of the fate of the pesticides. The facility consisted
of two inground compartments filled with muck soil (45.2% organic matter and
pH 4.5). The inground compartments constructed with a concrete bottom liner
and concrete walls. The parent pesticides, their major degradation products
and the potential evaporation loss of the parent were monitored every week
from June to October over a two-year period, 1990-1991. Three soil samples
were taken from each compartment each week. Air samples were collected
every week from above the compartments at two different heights 15 and 200
cm. Four pesticides have been selected for this study. endosulfan I and II
(Thiodan), chlorpyrifos (Dursban). alachlor (Lasso), and simazine (Princep).
HPLC and capillary GLC with electron capture (E00) and nitrogen-phosphorus
(NPD) detectors, were used to identify and quantify the pesticide residues and
their degradation products.

Volatilization loss was the dominant dissipation route for all four of the

pesticides in the soil. The average potential dissipation of the selected

pesticides were used in the study in 1990 and 1991 were 66.9 % and 67.3 %
respectively for endosulfan l + II, 69.9 % and 81.5 % for chlorpyrifos, 84.7
% and 84.2 % for alachlor and 87.1 and 90.0 % for simazine. The pesticides
waste disposal facility at Michigan State University was a good method for the

dissipation of all four of the pesticides that were studied.

DEDICATION

TO THE MEMORY OF MY FATHER

iv

ACKNOWLEDGEMENT

I would like to express my sincere appreciation to my major professor ,
Dr. Matthew zabik for his encouragement, guidance, support, friendship,
patience and all he has done for me throughout the course of this investigation.
He really has earned my highest level of respect and admiration.

I would also like to extend my appreciation to Drs. Donald Penner, Roger
Hoopingarner, Frank D’itri and Richard Leavitt for serving on my graduate
committee. Special thanks to Dr. Robert Kon for his helpful discussions and
suggesfions.

Special thanks to my parents and every one of my family for their
encouragement and support, I will always be grateful to you all.

Finally I would like to extend my appreciation to all my special friends,
Emad Zidan, Ahmad Madkour, Ali Eldarwesh and Michael Matthews for all that
we shared together. also special thanks to every one in Dr. Zabik’s lab and Dr.

Leavitt’s lab.

 

TABLE OF CONTENTS

LIST OF TABLES

LIST OF FIGURES

CHAPTER 1: INTRODUCTION AND LITERATURE REVIEW
Photodegradation of pesticides
Environmental dynamics of pesticides
Behavior of pesticides in the environment
Fate of pesticides in soil
Volatilization of pesticides in soil
Effect of soil microorganisms on pesticides
Chemical degradation of pesticides in soil
Pesticides characteristics and toxicity
Disposal technologies

Incineration
Open burning
Physical/chemical methods
Land disposal
Pesticides characteristic and toxicity
Endosulfan (Thiodan)
Chlorpyrifos (Dursban)
Alachlor (lasso)
Siamazine (Princep)
Objectives of the study

CHAPTER 2: MATERIALS AND METHODS

l. MATERIALS
A. Samples
1) Soil
2) Air
B. Glassware preparation
C. Reagents
1) Solvent
2) Chemicals
3) Miscellaneous Items
D. Equipment

vi

viii

_|
ommmUT-J

11
11
12
13
13
14
15
15
16
16
18
19
20
22

26

27
32
32
32
33
34
34
34
34
34

ll. METHODS

A. Air analysis
Recovery study
Freezer study

B. Soil analysis
Extraction
Recovery study
Freezer study

C. Detection of air and soil samples
D. Calculation of the pesticides concentrations
E. Chromatographic conditions

1) Gas chromatography-ECO
2) Gas chromatography-NPD
3) HPLC conditions

4) pH determination

5) Organic matter

6) Cation exchange capacity

CHAPTER 3: RESULTS AND DISCUSSIONS

ENDOSULFANI + II
CHLORPYRIFOS
ALACHLOR
SIMAZINE

CHAPTER 4: SUMMARY AND CONCLUSIONS

LITERATURE CITED

vii

35
35
36
37

38
39
39
41

42
42
43
43
43
44
45
45
45
48
51
60
69
78
95

98

 

LIST OF TABLES

-\

Table
Table 2: The pesticides used in the study.

Table 3: The parent pesticides and their metabolites.
Table 4: Weight of the pesticides used for the study.
Table 5: Recovery % of the selected pesticides.

Table 6: Recovery % of the selected pesticides after
storing for six monts.

Table 7: Recovery % of the parent pesticides and their
metabolites from soil.

Table 8: Recovery % of the parent and their metabolites
from soil after storing for six months.

Table 9: Characteristics of the soil used in the waste
disposal facility at Michigan State University.

Table 10: The effect of the wind speed on the distribution of
Endosulfanl + II.

Table 11: The effect of the height and the wind speed on the
evaporation loss of Endosulfan l + II.

Table 12: The effect of the wind speed on the distribution of
Chlorpyrifos.

Table 13: The effect of the height and the wind speed on the
evaporation loss of Chlorpyrifos.

Table 14: The effect of the wind speed on the distribution
of Alachlor.

Table 15: The effect of the height and the wind speed on
the evaporation loss of Alachlor.

viii

: Characteristics of the pesticides used for this study.

21
24
25
31

36

37

4O

41

47

54

55

65

66

74

75

Table 16: The effect of the wind speed on the distribution
of Simazine.

Table 17: The effect of the height and the height and the
wind speed on the evaporation loss of Simazine.

Table 18: The evaporation loss of the selected pesticides at
the average height and wind speed.

Table 19: The average potential dissipation of the selected
pesticide used in the study of the Fennvill,

Michigan waste disposal facility in 1990 and 1991.

ix

82

83

91

98

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

Figure

1:

1A:Location of the waste disposal facility used for the study.

2:

3:

LIST OF FIGURES

Diagram of the top view of the pesticides waste disposal
facility at Michigan State University.

The average potential distribution of endosulfan l + II
at the average wind speed and average height in the
the waste disposal facility in 1990 and 1991.

The effect of the height and wind speed on the
potential evaporation loss of endosulfan l + II
in 19901nd 1991.

4: The effect of wind speed on the potential distribution
of endosulfan I + II at the average height in 1990.’

5: The effect of wind speed on the potential distribution
of endosulfan | + II at the average height in 1991.

6:

The average potential distribution of chlorpyrifos at
the average wind speed and height in the waste
disposal facility in 1990 and 1991.

: The effect of the height and wind speed on the potential

evaporation loss of chlorpyrifos in 1990 and 1991.

: The effect of wind speed on the potential distribution

of chlorpyrifos at the average height in 1990.

: The effect of wind speed on the potenial distribution

of chlorpyrifos at the average height in 1991.

10: The average potential distribution of alachlor at the

11:

12:

average wind speed and height in the waste disposal
facility in 1991 and 1991.

The effect of height and the wind speed on the potential
evaporation loss of alachlor in 1990 and 1991.

The effect of wind speed on the potential distribution
of alachlor at the average height in 1990.

29

3O

56

57

58

59

67

68

69

7O

76

77

78

Figure 13: The effect of wind speed on the potential distribution
of alachlor at the average height in 1991.

Figure 14: The average potential distribution of simazine at the
average wind speed and height in the waste disposal
facility in 1990 and 1991.

Figure 15: The effect of the height and wind speed on the potential
evaporation loss of simazine in 1990 and 1991.

Figure 16: The effect of wind speed on the potential distribution
of simazine at the average height in 1990.

Figure 17: The effect of wind speed on the potential distribution
of simazine at the average height in 1991.

Figure 18: The relationship between water solubility and
evaporation loss of the pesticides.

Figure 19: The relationship between Henry’s law constant
and evaporation loss of the pesticides.

Figure 20: The average mass balance relationship for the
pesticides used in the study of the Michigan State
University waste disposal facility in 1990.

Figure 21: The average mass balance relationship for the

pesticides used in the study of the Michigan State
University waste disposal facility in 1991.

xi

79

84

85

86

87

92

93

94

95

 

CHAPTER 1'

INTRODUCTION AND LITERATURE REVIEW

 

INTRODUCTION -

Widespread use of pesticides has greatly benefited agriculture, but has
also led to many problems. One of these problems is the effect of pesticides on
the environment including environmental contamination by improper disposal
of dilute pesticide wastes.

Handling and disposal of agrichemical wastes represents a potentially
serious problem in Michigan and worldwide. Large volumes of dilute pesticide
wastes result from livestock dipping operations, over estimating the amount
needed for a spray operation, and cleaning and rinsing equipment. For such
operations, safe facilities and procedures are essential to degrade the pesticides
in proper way in the environment and protect human health and the
environment. Degradation facilities must be developed which are simple to use,
reliable and inexpensive.

Degradation is the most widespread phenomenon contributing to the
disappearance of pesticides from soils. There the soil is an ideal medium for
inducing transformation reactions of pesticides. Usually moist and aerated
upper layer of soils provides the proper conditions for chemical changes,
(mainly hydrolysis, oxidation reactions) responsible for biodegradation occurring
in the soil solution. Under anaerobic conditions, such as those specific to
flooded soils, reductive reactions prevail. Possessing a large and active surface

area, soil colloids may induce surface-catalyzed degradation reactions of

3

adsorbed pesticides. At the same time, adsorption of pesticides to the soil
particles strongly affects the availability of pesticides for transformation
reactions. Sorption and desorption of a chemical by soil particles in soil-water
system influence transport and transformation of the chemical in the
environment (Bouchard 1989).

Soil is a complex and highly variable mixture of components containing
many types of living organisms, i.e., bacteria, fungi, invertebrate and vertebrate
animals. The soil microorganisms are most important because these metabolize
or attenuate pesticide wastes. Under proper environmental conditions and with
sufficient time, microbial degradation can play an important role in reducing
pesticide concentrations in soil by degrading these compounds into simple
compounds (Bingham 1973). Aromatic compounds are more resistant to
biodegradation than aliphatic compounds. Compounds which have carbon in the
skeletal chain or ring make the structure more susceptible to degradation
(Atkins 1972). Halogens on an aromatic ring increase resistance to
biodegradation, however, amino and hydroxy substitutions tend to increase
biodegradability (Bingham1973).

The most important soil characteristic related to pesticide degradation is
rich microbial population capable of attacking a wide variety of chemical
compounds. However, studies of pesticide degradation, carried out in the late
19605, mainly with organophosphate and s-triazine, showed that in addition

to microbiological processes, nonbiological processes such as the chemical and

4

physical properties of the soil plays an important role in the degradation of
pesticides.

Oxidation and hydrolysis may degrade a pesticide into smaller
components, or remove various functional groups. Hydrolysis occurs faster
when pesticides are absorbed onto clay or silt particles (Baker 1972). Alkaline
pH can also significantly influence degradation. Malathion was demonstrated
to have hydrolysis half-lives at pH 7 and pH 9 of one month and ten hours,
respectively (Paris 1975). Alkaline hydrolysis is not effective with every
pesticide but has been shown to work with organophosphate, carbamate, imide
and hydrazide (Ferguson 1975). Volatilization is an additional mechanism for
pesticides transport from treated agricultural lands in the vapor phase into the
atmosphere. Potential volatility of pesticides is related to their inherent vapor
pressure, but the actual vaporization rates depend on the environmental
conditions and other factors that control behavior of the chemical at the
solid-air-water interface. Volatilization and air transport is a major pathway of
pesticide movement. Some are transported long distances in the atmosphere
and return to the soil and water surfaces contributing to widespread non-point
environmental contamination. Moisture may become the critical factor in the
control of volatilization (Glotfelty et al. 1984). The potential for pesticide
volatilization is related to pesticide vapor pressure, but actual volatilization rate
is dependent upon the environmental factors that modify or attenuate the

effective vapor pressure of the pesticide. The two primary environmental

5

factors affecting volatilization from the soil surface are temperature, which
influences the vapor pressure, and air movement (Nash 1983). It has only been
recognized within the last decade that volatilization losses can contribute
substantially to the removal of organic chemicals from soil. (Glotfelty et al.
1984). Trifluralin vapor pressure increases approximately five times for each
10-degree increase in temperature between 20 °C and 40°C (Spencer 1974).
PHOTODECOMPOSITION OF PESTICIDES

Photochemical reactions may occur when a pesticide absorbs light energy
of a particular wavelengths (Zabik 1983). In some cases, the energy involved
is dissipated by the breaking of chemical bonds in the molecule. Photochemical
reactions of pesticides are chemical processes that begin when radiation
interacts with the pesticide molecule. The overall photochemical reaction can
be divided into two parts: primary processes and secondary reactions. The
primary photochemical processes involve a series of events that start with the
absorption of a quantum of radiation by a molecule and ends with the
disappearance of that molecule or its conversion back to its initial ground state
or to different excited states. The secondary reactions are those
nonphotochemical processes that lead to chemical products. The photochemical
reaction of any pesticide involves two operations: (1) absorption of energy
leading to excited states, and (2) the transformation of the various electronically
excited states to chemical products. Light absorption by molecules involves

transitions of electrons from one orbit to another, together with changes in the

6

rate of rotation and vibration of atoms within the molecules. Rotational changes
rarely result in photochemical reactions in complex molecules.

The excitation of an electron, bonded or nonbonded, to an excited state
requires that the exited electron arrives spinning in the same direction as it did
in the ground state. The resulting excited state with retained electron-spin
configuration is called an excited singlet state back to the singlet ground state
is called fluorescence and occurs in approximately 1O’7s or less. Transition of
the excited singlet state to the excited triplet state occurs by reversal of the
spin of the electron that was excited. This process is called inter-system cross
triplet excited state is always of lower energy than the excited singlet state and
the direct transition from the singlet ground state to the excited triplet state
which is also forbidden (of low probability). Consequently, the triplet state lives
longer than the singlet state. This longer life allows most molecules in the triplet
state to react before transition to the ground state occurs. Emission from the
excited triplet state called phosphorescence and generally requires 10'4s or
longen

A photochemical reaction can also be initiated through sensitization. In
sensitized photochemical reaction a donor molecule absorbs the radiation and
becomes electronically excited. This excited donor molecule, through energy
transfer processes, imparts its energy to an acceptor molecule (i.e. pesticide)
which then reacts chemically. Generally the donor molecule is excitedto its

triplet state. In order for triplet triplet energy transfer to occur, the triplet

7

excited state of the sensitizes (donor) must be energetically above the triplet

excited state of the acceptor (pesticide).

Duh-vDat

D’+A - A’+D

A‘ = producer
Chemical products can, therefore, be produced from the excited singlet

state and/or the excited triplet state. The products produced via the singlet may

or may not be the same a those produced via the triplet.

.S'-~""-’S1 .. products

T1 ~130de
The failure of a pesticide to react photochemically may be due—to its
inability to absorb the given wavelengths of light it is exposed to, or on
absorption of light the excited states formed dissipate their energy through
fluorescence, phosphorescence and/or other collisional processes. PCBs
(polychlorobiphenyls) are thermally and biologically non-degradable.
Photochemical degradation is shown to be a major, if not the only, degradation

pathway since solar radiation of the wavelength required is present (Zabik

8

1983). PCP (pentachlorophenol), was found to decompose readily in sunlight
whether in ionized form (Munakata and Kuwahara 1969) or not (Hamad,
1967). Methoxychlor in aqueous alcohol was converted to
dimethoxybenzophenon, p-methoxyphenol and anisic acid (Fernandez, 1966).
ENVIRONMENTAL DYNAMICS OF PESTICIDES .

Environmental dynamics of pesticides includes all processes that occur
from the times of application into the environment until their degradation
products or parent compound reach some steady state. The environmental
dynamics includes irreversible binding to soil particles, mineralization or
incorporation into biological material. This phenomena may be divided into three
groups: distribution, movement, and attenuation. Distribution determines how
pesticides or their degradation products can move from their original location
to new locations by wind, erosion, volatilization from soil, plant, aqueous
surfaces, and diffusion and/or mass flow in the .soil air. Pesticides movement
can occur with or in the soil water, leaching down and through the soil or back
to the soil surface with evaporation. Water runoff and soil erosion can carry
pesticides over land, either in solution, adsorbed on sediment, or in the
crystalline state. Pesticide attenuation refers to all the processes that tend to
reduced the amount of free pesticide and residue in the environment. These
processes include: chemical, photochemical and biological degradation,
irreversible soil adsorption, and plant and other organisms uptake. Volatilization

may be considered an attenuation mechanism when a pesticide is dissipated by

this route.
BEHAVIOR OF PESTICIDES IN THE ENVIRONMENT

Behavior of pesticides in the environment is influenced by many factors:
(1)- physical and chemical properties of pesticides which include chemical
structural and configuration, molecular size, water solubility, lipophlicity,
polarity, acidity or basicity, and vapor pressure. (2)- soil characteristics, which
effect pesticides behavior include: soil type (percent silt, clay, organic matter,
oxides, hydroxides) clay type, pH, soil structure (pore size, bulk density), cation
exchange capacity and microbial population. (3)- environmental factors that
influence pesticide behavior include: temperature, air movement (speed,
direction, turbulence) rainfall (amount, intensity, duration, chronology of
events), humidity, solar radiation, topography.
FATE OF PESTICIDES IN SOIL

The fate of pesticides in soil is ultimately connected with such expression
as "disappearance" or dissipation and "persistence" or accumulation in the
environment. The term disappearance of a pesticide from a certain substrate
has been widely used in the past and was, in most cases, synonymous with the-
difficulty to detect the originally applied compound where it previously had been
applied. Disappearance or loss through volatilization means, the parent
compound or its metabolites really has not disappeared, but that they have
been transported some where else (Lichtenstein 1970). On the other hand,

persistence has to be regarded in relation to the area to which the pesticide has

10

been applied. This persistence depends on different factors: the physical and
chemical properties of the pesticide itself, the formulation in which it has been
applied and the mode of its application to the soil or other target area.

Overall the most important environmental factors effecting the fate of
pesticides are: soil type, soil microorganisms, the presence of other chemicals,
temperature, moisture, air movement, cover crops, soil cultivation, plant
surfaces, etc. (Lichtenstein and Schultz 1962, 1964). Because these factors
differ from place to place, it is impossible to attribute an absolute half life to any
pesticide. Dependent on the environmental conditions, pesticides may have a
relatively short persistence or may be detectable for a relatively long time.
VOLATILIZATION OF PESTICIDES

Volatility of several pesticides is found to be a function of the vapor
pressures and water solubilities of each pesticides. This loss was also
dependent on the substrate into which the pesticide had been incorporated.
Pesticides bound to soil particles can volatilize, they are considerably more
volatile when dissolved in water (Lichtenstein and Schultz 1961). Several
researchers have reported higher rates of volatilization of insecticides and
herbicides from wet than from dry soils (Bowman et al., 1965, Gray and
Weierich1965 and Parochetti and Warren 1966). Increase volatility in wet soils
is due to displacement or desorption of the pesticide from the soil surface,
resulting in an increased vapor density or partial pressure of the pesticide

(Spencer et al., 1969c; 1970b). Soil-water content affects volatilization losses

11

of organochlorine pesticide simply by competition for adsorption sites (lgue et
aL,197OL
EFFECT OF SOIL MICROORGANISMS ON PESTICIDES

Soil microorganisms have a considerable effect on the stability of
pesticide in the soil (Lichtenstein and Schultz 1960). The effect of moisture and
soil microorganisms on parathion was reported by Lichtenstein and Schultz
(1964). Parathion was most persistent in dry soil and least persistent in soil
with a high moisture content. The role which soil microorganisms play can be
seen by measuring the rate of decomposition in sterilized versus non-sterilized
soils (Kanfman et al. 1986). A general review on the subject of microbial effect
on pesticide degradation in the soil can be found by Wainwright (1978). In
general, factors which effect microbial degradation are soil moisture,
temperature, percent organic matter, pH and pesticide concentration.
CHEMICAL DEGRADATION OF PESTICIDES IN SOIL

Hydrolysis, oxidation and isomerization are the three most prevalent
reactions in soil. Hydrolysis is faster in the moist soils than dry soils. Oxidation
reaction of parathion to paraoxon was reported by Helling et al, (1971).
lsomerization of parathion in soil can be demonstrated by conversion of the

sulfur thion (=s) to thiol (-s-) as in s-methyl parathion.

1 2
PESTICIDE CHARACTERISTICS AND TOXICITY

Chlorinated hydrocarbons are more persistent in the environment than
other classes of pesticides. Organophosphate are often more toxic to humans
than chlorinated hydrocarbons; however they are deactivated in the
environment much more rapidly. Carbamate are similar to organophosphate in
their persistence and they are rapidly degraded in the environment.
Organophosphate and carbamate toxicities vary widely some are less toxic than
DDT while others have four or five times higher toxicity. The toxic action of
organophosphate and carbamate pesticides is to deactivate the
acetylcholinesterase enzyme. While the organochlorine pesticides can also be
classed as neuropoisons. However, their mechanism of action is not the same
as that of phosphates and carbamate.

Microbial metabolism, chemical reaction, and photodecomposition are the
processes of great significance in degrading chlorinated hydrocarbon pesticides
in soil. Strong adsorption to soil constituents limits the availability of these
chemicals and their degradation products for more rapid degradation in soil.
Although both anaerobic and aerobic degradation of chlorinated hydrocarbons
have been observed in the environment, it is generally believed that anaerobic
degradation is more rapid (Hill and McCarty, 1967).

Organophosphate pesticides degrade fairly rapidly in soil. The rate of
degradation increases with increased soil moisture content, temperature, and

acidity (Harris and Lichtenstein, 1961 ). These factors enhance pesticides loss

13

by chemical degradation, volatilization, or microbial activity. Carbamate
pesticides have a relatively short residual life in soil, and they are readily
degraded by non target organisms.
DISPOSAL TECHNOLOGIES

The seriousness of the hazard to human health and the environment
resulting from mismanagement of pesticide waste in particular and hazardous
wastes in general became increasingly clear. As a part of this general
awareness and as the use of pesticides continued to grow resulting in more and
more pesticides wastes to be disposed of, the problem of pesticide waste
disposal became a point of major concern. There are many disposal systems
that might be candidates.
INCINERATION

A "pesticide incinerator" is defined as any installation capable of the
controlled combustion of pesticides at a temperature of 1000 °C for two
seconds dwell time in the combustion zone, or lower temperatures and related
dwell times that will assure complete conversion of the specific pesticide to
inorganic gases and solid ash residues (U. S. EPA 1974). In addition an
incinerator must meet the performance standards promulgated under RCEA (40
CFR 264 Subpart 0) if pesticides regulated under RCRA are to be burned. This
means an incinerator must be capable of destroying or removing 99.9% of the
pesticide put into it.

Incineration of pesticides and/or containers requires special equipment

14

that is not widely available. Due to the highly specialized nature of an
incinerator that can meet the specifications necessary to destroy complex
pesticide formulations, plus the energy requirements, the process can be very
expensive and not generally the method of choice for small quantities that may
be generated by a farmer, for example. On the other hand, it can be a highly
effective means of disposing of unwanted material (Ferguson 1975).
OPEN BURNING

Open burning is defined as combustion of a pesticide or pesticide
container in any fashion other than incineration (U.S.E.P.A. 1974). Open
burning is usually done by the simple act of piling up empty paper bags or
plastic jugs and setting them on fire and is commonly used to dispose of
combustible empty containers where local regulations permit the practice. It is
sometimes prohibited by regional air quality regulations. Where it is permitted,
open burning represents an inexpensive and convenient way of disposing of the
combustible containers that are commonly used to package pesticides. The
practice can present hazards to worker health and to other persons, plants and
animals that may be in the vicinity. The impact upon the environment is mainly
through dispersal of combustion gases, smoke and fumes into the atmosphere
and through contamination of soils and waters by ashes and partially burned

containers holding toxic residues.

1 5
PHYSICAL/CHEMICAL METHODS

Chemical deactivation/detoxification provides the opportunity to reduce
a toxic chemical to a non-toxic state. It is a procedure that is not currently used
to any significant degree in common disposal systems even thought there are
many pesticides that can be successfully degraded when mixed with an. alkali
or acid solution or in some cases a specially prepared enzyme. The principal use
would be in rinsing containers in situations where the reinstate cannot be added
to the mix.
LAND DISPOSAL

Land disposal is the most widely used, least expensive, and most often
available disposal system at the present time. The term "land disposal"
includes sanitary landfills, surface impoundments, evaporation ponds and land
farming. Land disposal in sanitary landfills, permitted to accept wastes can be
expected to be the method of choice for the majority of the disposal system.
Pesticides waste and other wastes are commonly disposed of in a sanitary
landfill or buried at the site of use.

Research was conducted at Iowa State University on a concrete pit
pesticides waste facility. The results revealed that the facility was safe from
leakage, did not present a hazard of air pollution, and allowed chemical and

microbial degradation of the deposited materials (Hall 1984).

l6
CHARACTERISTICS OF THE PESTICIDES USED IN THIS STUDY

ENDOSULFAN (THIODANI
C1

C1\/ c1\ C1

C1 C1
C1

 

 

o\szo
c1 0\ c1 0

Cl ' 0/ Cl
endosulfan II
endosulfan I

Endosulfan is a mixture of two stereoisomer, alpha-endosulfan, or
endosulfan I, with a melting point of 108 to 110 °C, and accounts for 70% of
technical endosulfan. Beta-endosulfan, or endosulfan II, with a melting point of
208 to 210 °C, and accounts for 30% of technical endosulfan. Endosulfan is
a non-systemic contact and stomach insecticide. It is used for controls of
aphids, trips, beetles, foliar feeding larvae, mites, cutworms and bugs. The

acute oral LDso for rates of the technical product in oil solution for rates is 80

to 110 mg/kg.

C1 C1

C1

0\ 5/0

c1 C1 0/ 2'0

Endosulfan sulfate

17

Soil pH has a great effect on the degradation of endosulfan, the higher the pH
the higher the degradation rate (Guerin 1992). Endosulfan isomers can be
dissipated in simple aqueous systems at neutral pH in the absence of biological
material or chemical catalysts (Guerin 1992). In another study, incubations in
lake water showed that the half-life of endosulfan l was 35 days at pH 7 and
105 days at pH 5.5 (Greve and Wit, 1971). The major oxidation product of
endosulfan I and II, endosulfan sulfate, is less volatile and very stable and can
persist longer than either of the parent compounds in the same system (Guerin
1992). Endosulfan sulfate is formed in many natural environments through
biological oxidation and is only slowly chemically and/or biologically degraded

(Miles and Moy 1978).

18

CHLORPYRIFOS (DURSBAN)

‘ CI CI

HSCT—O H

P— N/
/ ll

0 Cl

chlorpyrifos ( Dursban)

The solubility of chlorpyrifos in water at 35 °C is 2 mg/l. It has a broad
range of insecticidal activity and is effective by contact, ingestion and vapor
action. It is non-systemically active. It is used for the control of mosquitoes
(larvae and adults), flies, various soil and many foliar crop pests and household
pests. It is used for ectoparasite control on cattle and sheep. The acute oral
LDso for male rats is 163 mg/kg, for female 135 mg/kg. Breakdown in soil is
mostly by microbial metabolism. In leaching experiments, most of the
chlorpyrifos remain in the upper 2" of soil having organic carbon content above
1 %. The major degradation metabolite of chlorpyrifos is 3,5,6-trichloro-2-

pyridinol and used for this study.

Cl CI
\

I
OH NCI

3, 5, 6 - trichloro-Z-pyridinol

19

ALACHLOR ILASSOI
ii
H30— O—CHz— C i C ——CH CL
\ / 2

N
CH3-H2C O CH2— CH3

alachlor (Lasso)

groundwater at levels from 0.01 to 16.6 ppb in 3 states. Microbial degradation
is the major mode of degradation (Beestman and Deming 1974) r mode below
the root zones but slow. Alachlor reaches groundwater in cooler climates of
Iowa and Indiana than in the southeast. It controls most annual grasSe‘s and
certain broadleaf weeds in corn, dry beans, peanuts, soy beans (Farm chemicals
handbook 1993). The major metabolites of alachlor is 2,6-diethylaniline and

used for this study.

NH2
H3C-—CH2 O HrCHa

2,6—diethylaniline

20
SIMAZINE (PRINCEPI

CzHg— NH—(Nxfi—NH—CZHs
N / N
I.
simazine (Princep)

Simazine is a selective herbicide that controls most annual grasses and
broadleaf weeds in corn. It is solubility in water 3.5 ppm at 20°C. Simazine
was detected in the groundwater over a half of the states in the United State
of America. Some wells were found to contain atrazine and simazine in level
above the EPA health advisory limit (Parsonsns and Witt 1989). The major

metabolite is 2,6-diethylamine-4-hydroxy-s-triazine and used for this study.

czHg—NH—erxtNH—CZHS
N / N
13H

2,6 diethylamine-4—hydroxy-s-triazine

TABLE 1 . CHARACTERISTICS OF THE PESTICIDES USED FOR THIS STUDY

 

 

 

 

 

 

Pesticides Vapor Water Log Henry’s Molecular
Presser Solubility Kow Calculated Weight
Torr ppm at atm-m3lmole
20°C
Endosulfan I + II 9.00E -3 0.6 3.8 1.12 E -5 404.88
Chlorpyrifos 1.87E -5 2.0 4.70 4.31 E -6 350.58
Alachlor 2.20E -5 2.42 2.64 3.23E 78 269.77
Simazine 6.10E -9 3.50 2.51 4.62E -10 201.66

 

 

 

 

 

 

 

21

22

OBJECTIVE OF THE STUDY
The objective of this study was to determine the fate of selected

pesticides in a soil-filled waste disposal facility by the determination of the

following :
1- the major metabolic products for each pesticide.
2- the average evaporation loss for each parent pesticide at specified height

and average wind speed.
3- the parent pesticides residues remaining in the soil compartments.

4- the percent of the degradation for each pesticide.

A pesticide waste disposal facility located at Michigan State University,
Trevor Nichols Research Station, Fennville, Michigan was used for this study.
A two-year study of pesticide residues and their major degradation products in
the soil tank and evaporation loss of the parent pesticides above the
compartments were conducted. This study focused on the fate of the selected
pesticides in this waste disposal facility.

More than 20 different pesticides (including pyrethriod, organochlorine,
organophosphate, carbamate pesticides, etc.) are used on the farm. Four
pesticides were selected from all these pesticides for use in this study. These
pesticides were selected because they represent different groups of pesticides

family (Table 2). The pesticides residues and their major degradation products

 

23

(Table 3) were monitored from June to October over a two-year period1990-
1991 in two soil compartments. The five pesticides were used for the study are:
- endosulfan l and II (Thiodan) as chlorinated hydrocarbon insecticide.
- chlorpyrifos (Dursban) as an organophosphate insecticide.
- alachlor (Lasso) as an acid amide herbicide.

- simazine (Princep) as a triazine herbicide.

TABLE 2. THE PESTICIDES USED IN THE STUDY

 

COMMON NAME

FAMILY

ACTION

 

endosulfan l & Il (Thiodan)

chlorinated bicycled

insecticide &

 

 

 

 

sulfite acaricide
chlorpyrifos (Dursban) phosphorothioate insecticide
alachlor (Lasso) acid amides (acetanilide) herbicide
simazine (Princep) triazine herbicide

 

 

 

24

 

TABLE 3. THE PARENT PESTICIDES AND THEIR METABOLITES

ll PARENT PESTICIDES l METABOLITES ll

edosulfan (Thiodan)
6,7,8,9,10-hexachloro-
1 ,5,5a,6,9,9a-hexahyro-6-9-methano

2,4,3-benzodioxa—thiepin-3-oxide

*(1) edosulfan sulfate
(2) endosulfan ether

(3) endosulfandiol

 

chlorpyrifos (Dursban)
o,o-diethyl o-(3,5,6-trichloro-2-
pyridyl) phosphorothioate

*I1) 3.5,6-trichloro—2-pyridinol

(2) chlorpyrifos-oxon

 

alachlor (Lasso)
2-chloro-2’,6’-diethyl-N-

(methoxymethyl) acetanilide

*(1) 2,6-diethylaniline
(2) 2’,6’-diethylacetanilide
(3) 2,6-diethyl-N-(methoxymethyl)

anailin

 

simazine (Princep)
2-chloro-4-6—bis (ethylaminol-s-

triazine

 

 

*(1) 2,6 diethylamine-4-hydroxy-s-
triazine

(2) 2,4—diamino-6-chloro-s-triazine

(3) 2-amino-4-chIoro-6-ethylamino

-s-triazine

 

* The major metabolites used in the study

25

 

CHAPTER 2

MATERIALS AND METHODS

MATERIALS AND METHODS
MATERIALS
The pesticide waste disposal facility at Michigan State University was
utilized as an experimental site for a single inground compartment. The facility
had been modified to give a better distribution‘pattern of the dilute wastes
over the entire soil surface.

The pesticide waste disposal facility consisted of two compartments
each one filled with muck soil. These two plots (compartments) separate from
each other and each one has concrete wall and a concrete liner (Figure 1).
Three known inputs of selected pesticides were applied to plots 1 and 2’from
June to October in 1990 and 1991. These selected pesticides were monitored
for the parent compounds and their major degradation products in each plot.
Air samples were collecting from above the two plots at two different heights;
15 and 200 cm.

|- Complete meteorological data were collected at the time of sampling
which included measurement of

a) Air temperature.

b) Wind speed.

c) Soil temperature.

d) Relative humidity.

e) Rain fall.

28

In 1990 and 1991 a mixture of the selected pesticides were applied at
three separate intervals, early, mid and late summer ( June 7, July 13 and
August 30 of 1990 and June 14, August 10th and September 17 of the
1991)

The following amounts of the formulated pesticides were used for the
application. 1) 454 g of 80 WP wettable powder simazine (Princep), has 80%
active ingredient of simazine (363.2 g), 2) 375 g of 50 WP wettable powder
chlorpyrifos (Dursban), has 50% active ingredient ofdursban (187.5 g), 3) 227
g of 50 WP wettable powder endosulfan (Thiodan), has 50% active ingredient
of endosulfan (113.5 g), 4) 300 g (emulsifiable herbicide) of alachlor (Lasso),
has 45.1% of alachlor (135.3 g) were added to 1900 L (500 gallons) of water
and mixed well. A volume of 760 L (200 gallons) of the solution of the
pesticides were applied to each plot (plot 1 and plot 2). Weight of the

pesticides in each plot is shown in (Table 4).

£922: 88m .5955
am 33:69— SmaB 5203on on. Co 39> no“ 05 Co E890 ._. 9.sz

:8 vans.
m 8.325.: 80
m6 In =ow

$~d~ .583 8.890
3%: 5sz £590

 

29

>633 can 5.. now: 5:63 Emonflu 8mm; 65 Co c0380. as... .<r 2:9".

 

wonosm
a_a—o .um
no_:en
annuaem
vuofiugpsow
ooumsafiax
use—awn:
coonncu:
cacopfiq
gonnc ==c
«genie:
m=m~auuw
.psfifim
cuppa:
magma: usage
w_ogwun
uz_w=cq

 

wuHHHo

 

 

zcemzouz

 

 

 

 

3O

TABLE 4. WEIGHT OF PESTICIDES USED FOR THE STUDY

 

ll PESTICIDES

Weight of peeticidee

in plot 1

Weight of pesticides

In plot 2

Total weight of pesticides
applied in plots 1 8n 2 In 1990 &

1991

 

45.2 x 3 = 135.5 g

45 .2X3 =135.6g

135.6 X 2 X 2 = 542.4 g

 

Endosulfan I + II
Chlorpyrifos

75x3 =225g

75x3 =225g

225X2X2 =900g

 

Alachlor

54.1 X3

162.4 g

54.1 X3 = 162.4g

162.4X2X2 = 649g

 

Simazine

 

 

145.3 X 3

435.9.g

 

145.3 x 3 = 435.9 g

 

145.3 X 2 X 2 = 1743.6 g

 

31

 

32
A. SAMPLES

1 . Soil Samples

The pesticide waste disposal facility consisted of two plots. Each plot
was divided into three sections. Soil sample from each section was collected
using a stainless steel cylinder 40 cm long X 4.1 cm id. Each core soil sample
weighed about 100-200 g was collected through the total depth 80 cm of the
soil bed. Three soil samples were collected from each plot (plot 1 and plot 2)
each week. The day 0 soil samples were taken within 24 hr after the
completion of the application process. Each soil sample was mixed thoroughly
and a subsample was taken for analysis of the pesticides and their degradation
products. The soil in the degradation compartments were monitored for the
residue concentrations at weekly intervals for the pesticides and their

degradation products.

2. Air Samples

Samples of air were taken from the center of each plot (compartment)
at two different heights 15 cm and 200 cm every week for monitoring the
parent pesticides. Four air samples were collected each time. Two samples
from each plot. The air was monitored for the same pesticides as indicated. The
method was employed the use of polyurethane foam plugs (PUF) as described
by Glotfelty et al. (1989). Air samples were taken on the day of application and

for the next 24 hr and then every week. The air was drawn with an electric

33

vacuum pump equipped with four port manifold. The air-flow rate which was
measured by a flowmeter and controlled at 20 L/min. Each sampling cup was
connected to a sampling pump via tygon tubing. The air was sampling by 4.5
cm diameter X 5 cm in length plug of porous polyurethane foam (PUF) as the
sampling trap. The air-flow rates were measured at the beginning and at the
end of each sampling period. Total air volumes were calculated from the flow
rate and the duration of the sampling period. The PUF were position in glass
cylinders (cups) tapered at one end. The sampling probes were located at two
different heights above the soil surface 15 and 200 cm. Exposed plugs were
sealed in glass bottles with Teflon-lined caps and stored at -20°C prior to
analysis. The pesticides were recovered from the PUF plugs by 6—hr Soxhlet

extraction (30-40 cycles) using a 1:1 mixture of hexane and acetone.

B. GLASSWARE PREPARATION

Glassware (round-bottomed flasks, separatory funnels, beakers, funnels
and chromatographic columns) were thoroughly washed with detergent and hot
water, and then rinsed with distilled water followed by acetone. The glassware

were placed in a furnace and heated overnight at 350 °C before use.

34
C. REAGENT

1. Solvents
Acetone, acetonitrile, petroleum ether, hexane, methanol and ethyl acetate
were pesticides grade solvents (HPLC grade) and used as received.
2. Chemicals
- Sodium sulfate (granular, anhydrous) was reagent grade, and shown to be
free of interference to an electron capture detector.
- Florisil- PR grade, 60-100 mesh was activated at 135 °C for 48 hr before
use.
- Endosulfan l (Thiodan) (99.8%), Endosulfan ll (Thiodan) (97.9%), chlorpyrifos
(Dursban) (99.7%), alachlor (Lasso) (99.1%) and Simazine (99.6%). All
reference chemical standards were obtained from U.S. Environmental
Protection Agency (EPA), Pesticides and Industrial Chemicals.
3. Miscellaneous items.
- Glass wool (pyrex)- free of interference to an electron capture detector.
- Whatman extraction thimbles were single thickness free of interference,
33 mm X 94 mm.
D. EQUIPMENT
-Hewlett-Packard gas chromatography (GC) model 5890 series ll equipped with
dual detectors “Ni electron capture detector (ECD) and nitrogen-phosphorus
detector (NPD).

-Waters model 490 E, High Performance Liquid Chromatography (HPLC)

35

equipped with a variable wavelength detector (190-700 nm). Waters HPLC

pump model 501. - Zymark TurboVap evaporator.

METHODS
A. Air analysis

The PUF plugs were rinsed with distilled, deionized water in a Nalgen pipet
washer for six hours followed by soxhlet extraction with 500 ml acetone for six
hours and then 500 ml hexane for six hours prior to use (Turner and Glotfelty
1977).

Air samples were taken on the day of application and for 24 hr, and then
every week. Air was drawn at about 20 L/min through 4.5 cm diameter X 5 cm
in length plug of PUF. The polyurethane foam plug was transferred into an
extraction thimble, and subjected to soxhlet extraction. Lindane was used as
internal standard by Spiking 1 ml of 20 ppm in the PUF. The pesticides were
recovered from the PUF plugs by 6-hr Soxhlet extraction (30-40 cycles) using
a 1 :1 mixture of hexane and acetone. Then the solvent extract was run through
3 g of sodium sulfate anhydrous (400 0C overnight before used). The solvent
extract was then concentrated to 20 ml by a rotary evaporator and transferred

into a vial. No clean up was made.

36

Recovery study

The recovery study was carried out by spiking 2 ml of 1 ppm of the
pesticides mixture alachlor, chlorpyrifos, simazine, endosulfan land endosulfan
II to three polyurethane foam plugs. The PUF plugs were left at room
temperature until dry. The extraction method described above was followed.

The average recoveries ranged between 82% to 96.3%. (Table 5 ).

TABLE 5. RECOVERY % OF THE SELECTED PESTICIDES

 

i PESTICIDES Sample | Sample Il Sample ll AVERAGE

Recovery % Recovery % Recovery % Recovery %

 

 

 

 

Endosulfan l 106 88 95 96.3
Endosulfan II 99.5 85 98 94.2
Chlorpyrifos 93 95 89 92.4
Alachlor 95 97 82 91.3

 

Simazine 82 79 85 82

 

 

 

 

 

 

 

37

Freezer study

The freezer study was carried out by spiking 20 ml of 1 ppm of the
pesticides mixture (alachlor chlorpyrifos, simazine, endosulfan I and endosulfan
II) to three polyurethane foam plugs (PUF). The PUF plugs were left in the room
temperature until dry. The plugs were kept in the freezer at -20 °C for 6
months. The extraction method described above was followed. The average

recoveries ranged between 79% to 90% (Table 6).

TABLE 6 . RECOVERY % OF THE SELECTED PESTICIDES AFTER

STORING FOR 6 MONTHS

 

PESTICIDES Sample I Sample I) Sample Ill AVERAGE

Recovery % Recovery % Recovery % Recovery %

 

 

 

 

 

 

 

 

 

Endosulfan l 90 88 92 90
Endosulfan ll 87 86 89 87.3
Chlorpyrifos 85 90 84 86.30
Alachlor 88 78 90.5 85.5

 

 

 

 

 

 

ll Simazine 75 ' 83 79 79

 

 

38

B. Soil analysis
1. Extraction

Two soil subsamples of 10 g each were taken. One soil subsample was
left at the room temperature until dryness and then weighted. The second soil
subsample was used for analysis before dryness. The reason for that is to
avoid the adsorption of pesticides to the soil particles and the evaporation of
pesticides from the soil subsample. The concentration of pesticides was
calculated based on the dry soil samples weight taken from the weight of the
first soil sample. The soil sample was spiked with lindane as an surrogate
standard. The soil sample was transferred into an extraction thimble and
subjected to soxhlet extraction for 8 hr. The solvent extraction was 50 ml
hexane, 50 ml acetone and 50 ml methanol. Then after extraction 50 ml of
deionized water was added to the solvent extraction. The solvent extraction
was partitioned with 50 ml of petroleum ether for three times. The extract was
then combined. A 2.2 cm i.d. chromatographic column was packed with 10 g
of activated Florisil (130°C overnight before used) and 3 g of anhydrous
sodium sulfate on the top of the column. The column was then washed with 50
ml of petroleum ether. The combined extract was run through the Florisil
column and collected. Then the column was washed with 50 ml of petroleum

ether was run after. The extract was concentrated to 20 ml as a final volume.

39

Recovery study

The recovery study was carried out by spiking 20 ml of 1 ppm of the
pesticides mixture alachlor, chlorpyrifos, simazine, endosulfan I, endosulfan ll,
endosulfan sulfate, 2,6 diethylamine-4—hydroxy-s-triazine, 3,5,6-trichloro-2—
pyridinol and 2,6-diethylanailine to three soil samples weighing 6 g each. The
soil samples were left at the room temperature until dry. The analysis method
described above was followed. The average recovery ranged between 71% to

97% (table 7 I.

40

TABLE 7. RECOVERY % OF THE PARENT PESTICIDES AND THEIR
METABOLITES FROM SOIL SAMPLES

 

 

 

 

 

 

 

 

 

 

 

CHEMICALS Sample I Sample ll Sample lll AVERAGE
NAMES Recovery % Recovers % Recovers % Recovery %
Edosulfan l 88 90 95 91
Endosulfan ll 85 88 83 85.3
Endosulfan 90 98 103 97
sulfate .
Chlorpyrifos 88 86 91 88.3
3,5,6- 79 75 72 75.3
trichloro-2—

pyridinol

Alachlor 92 89 84 88.3

2,6— 89 87 81 86.7
diethylaniline

Simazine 79 76 80 78.3

2,6 71 69 73 71
diethylamine-

4-hydroxy-s-

triazine

 

 

 

 

 

 

41

Freezer study

The freezer study was followed as the recovery study method. The soil
samples were kept in the freezer -20 °C for six months. The analysis method
above was followed. The average recovery ranged between 69.3% to 92.3%

(Table 8 ).

TABLE 8. RECOVERY % OF THE PARENT PESTICIDES AND THEIR
METABOLITES FROM SOIL AFTER STORED FOR 6 MONTHS

 

 

 

 

 

 

 

 

 

 

CHEMICALS Sample I Sample ll . Sample Ill AVERAGE
NAME Recovery % Recovery % Recovery % Recovery %
Endosulfan l 85 88 83 85.3
Endosulfan II 87 80 79 82
Endosulfan 95 92 ' 90 92.3
sulfate

Chlorpyrifos 90 85 83 87 .
356- 75 79 7o ‘ 74.7
trichloro-Z-

pridinol

Alachlor 91 86 81 86

2,6- 88 83 84 85
diethylanaline -

Simazine 88 77 80 81 .7

2,6 70 65 ' 73 59.3
diethylamine- ‘
4—hydroxy-s-

triazine

 

 

 

 

 

 

 

42

Detection of air and soil samples

The pesticides and their degradation products were quantified by using
HPLC and capillary GLC with a variety of detectors depends on the chemical
structure of the pesticide or the degradation products. A gas chromatograph
equipped with ”Ni electron capture detector was used for detection of
chlorpyrifos, alachlor, endosulfan l, edosulfan II and endosulfan sulfate. A gas
chromatograph equipped with nitrogen phosphorus detector was used for
detection of simazine and 2,6 diethylanalyine the breakdown product of
alachlor. Peak area were calculated using a Hewlett Packard Chemstation. HPLC
was used for detection and quantification of 2,6 diethylamine-4-hydroxy-s-
triazine and 3,5,6 trichlorpyridinol the breakdown products of simazine and
chlorpyrifos respectively.
Calculation of the pesticides concentrations

Ouantitation of the pesticides was based on peak area. A standard curve
was constructed for each pesticide from external standard at different
concentrations (0.5, 1 and 4 ppm). The amount of each pesticide in the soil
and air samples was determined from its standard curve. The following equation
was used to calculate the concentration of the pesticide in soil samples ppm

lug/g) or in air samples ug/m3 .

 

ug/g or ug/m3 =

43
Where:-
X= amount of pesticide from a standard curve*.
Vf= the final extract sample volume (ml).
Ws = weight of soil sample (9) or air volume.
* Linear regression was used for quantitation of the amount of the pesticides.
CHROMATOGRAPHIC CONDITIONS
Gas chromatography-ECO
Hewlett-Packard model 5890 series II gas chromatograph was used for
analysis. The following conditions were employed for the analysis.
Column : DB-5 fused silica capillary 'column (60 m X 0.25 mm i.d)
with 0.25 micron phase thickness (J & W Scientific).
Oven Temperature : Programmed from an initial

Injector temperature : 220 °C.

Detector temperature : 300 °C.

Carrier gas : Helium at a flow rate of 30 psi.

Make up gas : Nitrogen at flow rate of 20 psi

Integrator :Hewlett-Packard Chemstation was used for collecting the
data.

Gas chromatograph-NPD

Hewlett—Packard model 5890 series ll gas chromatograph was used for
analysis. The following conditions were employed for the analysis.
Column :DB-5 fused silica capillary column (30 m X 0.25 mm i.d.)
Oven temperature :Programmed from an initial of 140 °C to a final

180 °C at a rate of 2 °C/min

Injector temperature
Detector temperature
Carrier gas

Gas flows

Integrator

HPLC condition

44

:240 °C

:250 °C

:Helium at a flow rate of 20 psi

:Air at 60 ml/min and hydrogen 30 ml/min.

:Hewlett—Packard Chemstation was used for collecting

data.

High performance liquid chromatography (HPLC) reverse phase with UV

detector was used for the separation and identifying the 2,6 diethylamine-4-

hydroxy-s-triazine and 3,5,6 trichloropyridinol the metabolites of simazine and

chlorpyrifos. This instrument has a two-solvent system with gradient

programming capability and data processor (Maxima). The analyses were

performed at the following conditions:-

Column :Cyano column, 22 cm Length X 4.6 mm ID

Mobil phase :Solvent A: ethyl acetate with 10 % methanol

Solvent B: hexane

The solvent gradient starts at 2% A, increases to 10% A in 10

min. Then it drops back to 2% A in 5 min. Finally, the system is

stabilized for 5 min at 2% A before the next injection.

Flow rate :1 ml/min

Detector :UV absorbance detector at 310 nm (model 490 E) .

Pump :Waters model 501

45
PH DETERMINATION

pH was determined by following the method of Smith and Atkinson (1975).
Distilled water (50 ml) was added to 20 g of dry soil and thoroughly mixed. pH
determination were recorded by using pH meter model PHH-80 (AE Company).
ORGANIC MATTER

Organic matter was determined by the method of Miller and Keeney (1982).
A sample of 10 g of soil was taken, then dried in oven (95°C) for 2 to 3 hours
and then the weight was recorded as W1. The soil sample was placed in an
another oven for 24 hr at 420 oC. The sample was taken from the oven and
cooled in a desiccator and the weight was recorded as W2. The percentage
organic matter was calculated according to this formula.
W2

% organic matter = x 100
W1

 

CATION EXCHANGE CAPACITY (CEC)

The method of Warncke (1988) was followed for the analysis of CEO. A
sample of 2 g of soil was weighed and transferred to a 50 ml centrifuge tube.
Twenty ml of 1 N neutral ammonium acetate was added and mixed for 15 sec
with a Vortex mixer. The sample was allowed to stand for two hours. The
sample was mixed and centrifuged for 5 minutes at 2500 rpm. The supernant
liquid was decanted. These steps were repeated two more times. Ethyl alcohol
(95%) was then added, and mixed for 15 sec. This mixture was centrifuged

and the supernant liquid was the decanted. These last two steps were repeated

46

two more times. Five ml of an acidified sodium chloride solution (10% NaCl +
0.3 ml conc. HCL per liter) was added and mixed. The sample was transferred
quantitatively to a steam distillation flask using deionized distilled water. Six
drops of 10 N NaOH was added just prior to distillation. The steam was distilled
into boric acid collecting 30 ml (Blank for distillation = 5 ml NaCl solution +
10 ml distilled water).

I ml (8) - ml (b)] N
CEC =

 

8

Where:

ml (s) ml acid to titrate sample
ml (b) = ml acid to titrate blank

N

normality of acid

S = sample weight

TABLE 9. CHARACTERISTICS OF THE SOIL USED IN THE
WASTE DISPOSAL FACILITY AT MICHIGAN STATE UNIVERSITY

 

 

 

 

 

Soil Type Muck soil
Organic Matter 45.2 %
Organic Carbon 26.2 %

Soil pH 4.5

Cation Exchange Capacity 71.7 meq/1009

 

 

 

 

47

CHAPTER 3

RESULTS AND DISCUSSIONS

RESULTS AND DISCUSSIONS

The total weight of the pesticides residues, evaporation losses and the
major degradation products for Endosulfan l, Endosulfan ll, Chlorpyrifos,
Alachlor, and Simazine were monitored weekly from June to October in 1990
and 1991 in two soil degradation compartments. These compartments were
soil-filled, concrete-lined and used as an experimental pesticides waste disposal
facility. This facility is located at the Michigan State University, Trevor Nichols
Research Station in Fennville, Michigan. A known weight of each pesticides
was used (Table 4). The formulated pesticides were dissolved in water and
applied to the two soil degradation compartments. The application of the
pesticides was done three times each year for each compartment (plot) for two
years in 1990 and 1991 as multiple inputs each year. The data showed a
fluctuation in the concentration of the parent pesticides remaining in the soil
each week which may be due to the movement of pesticides upward and
downward in the soil column or dissipation of the pesticides. Also the major
degradation products showed an increase each week until a steady state was
reached after which they started decrease. Weekly analysis of soil samples
gave a good picture of the fate of each pesticide in the soil for the preceding
time period, as will as at the end of the first and second year. One major
metabolite from each pesticide and evaporation loss of each pesticide was

determined. Also the pesticides residues remaining in the two soil

50

compartments were determined. The potential average volatilization loss was
determined from the average of the two sampling heights and the average of
the wind speed for the week calculated from the average daily wind speed.
The effect of wind speed on the evaporation loss for all the four pesticides was
determined (Figures 3,7,11 and 15). The minimum volatilization loss was
calculated from the minimum wind speed which was 1 kph at the average
height 107.5 cm ( average of 15 cm and 200 cm). The maximum volatilization
loss was calculated from the maximum wind speed each day then the average
of the week at the average height at 107.5 cm. The effect of wind speed on
the potential distribution for each pesticide was determined at the average
height in 1990 and 1991 (Figures 4,5,10,11,14,15,18 and 19).

In addition the effect of the height on the evaporation loss was studied
for all the four pesticides (Figures 11,13,15 and 17). The air sampling height
greatly affected the calculated values for pesticide evaporation losses.

The average mass balance relationship for endosulfan, chlorpyrifos,
alachlor and simazine in 1990 and 1991 was calculated (Figures 18 and 19).
Also the average potential dissipation of the selected pesticides used in the
Fennvill, MI waste disposal facility in 1990 and 1991 was calculated (Table

19).

51

ENDOSULFAN I + u (THIODAN)

Endosulfan (45.2 g) which contain a mixtUre of endosulfan l + II was
applied to each soil degradation compartment (plot 1 and plot 2) three times a
year for two- years. A total weight of 135.6 g (0.34 mole) was applied in the
first year and 271.1 9 total (0.67 mole) for two years in each plot. The percent
distribution of endosulfan l + II in 1990 in the soil compartments (plot 1 and
plot 2) was determined by calculating the percent of the residues remaining in
the soil, the percent of endosulfan sulfate which is the major metabolites of
endosulfan I + II, and the percent of average evaporation loss of endosulfan l
+ II at the average wind speed and average height (Table 10). After the first
year in 1990, 30.17 % of endosulfan l + I) remained in soil plot 1 and 33.03%
in soil plot 2. The percentages for endosulfan sulfate were 2.14 % in soil plot
1 and 1.77 % in soil plot 2. The percentage from average evaporation loss of
endosulfan I + II was 70.22 % from plot 1 and 53.58 % from plot 2. After the
second year in 1991, 56.11% of endosulfan l + II remained in soil plot 1 and
48.35 % in the soil plot 2. The percentages for endosulfan sulfate were 0.85
% in soil plot 1 and 2.94 % in soil plot 2. The average percent evaporation loss
were 92.91 % from plot 1 and 59.36 % from plot 2. The average potential
distribution of endoSulfan l + II was calculated at the average wind speed and
height in 1990 and 1991 (Figure 2).

Using the minimum wind speed (1 kph) assumption, the average

52

evaporation loss from the two plots was 12.27% in 1990 and 12.29% in 1991
at the average height. The effect of wind speed on the evaporation loss of
endosulfan I + II is shown in table 10. The evaporation loss was also calculated
at the maximum wind speed and the average height. The evaporation loss was
higher in the second year than the first year which may be due the higher
concentration in the compartment due to the carry over from the first year or
due to the different weather conditions such as the wind speed, temperature,
or humidity. The effect of height had a large effect on the evaporation loss was
a major factor in the calculation of total loss (Table 11). The volatilization loss
measured at 15 cm was higher than at 200 cm. For average calculation, a
column of air from the soil surface up to 200 cm which was close to the roof
of the facility, was taken into consideration. Therefore average evaporation loss
at 107.5 cm (average of 15 cm and 200 cm) was employed for the
calculations.

For endosulfan I and II loss due to volatilization was the highest route of
dissipation from the soil degradation compartments. The high volatilization of
endosulfan I + II was due to its low water solubility and relatively high vapor
pressure which is indicated by its Henry’s law constant (1 .12X 105). On the
other hand, the oxidation product, endosulfan sulfate, showed the lowest route
of dissipation which may be due to the pH of the soil (4.5) or the low
population of the microorganisms which are responsible for the oxidation of

endosulfan. Soil pH has a great effect on the degradation of endosulfan, the

53
heigher the pH the heigher the degradation rate (Guerin 1992).

The average mass balance relationship for endosulfan I + II in 1990 was
64.89 % as the average evaporation loss, 2.1 % as endosulfan sulfate and
33.1 % as a remaining of the parent in the soil (Figure 18). Also in 1991 the
relationship of the average mass balance was calculated and the average
evaporation loss from the two plots was 58.4 %, endosulfan sulfate 1.5 % and
the remaining of the parent 40.1 % (Figure 9). Over all the dissipation of

endosulfan l + II in 1990 was 66.99 % and 59.9 % in 1991.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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60

QHLQRPYRIFQ§ D R BAN

Chlorpyrifos (75 g) was applied to each soil degradation compartment
(plot 1 and plot 2) three times a year for two years. A total Weight of 225 g
was applied in the first year and 450 9 total for two years in each plot. The
percent distribution of chlorpyrifos in 1990 in the soil compartments (plot 1 and
plot 2) was determined by calculating the percent of the residues remaining in
the soil, the percent of 3,5,6 trichloropyridinol which is the major metabolites
of chlorpyrifos, and the percent of average evaporation loss of chlorpyrifos at
the average wind speed and average height (Table 12). After the first year in
1990, 21.9 % of chlorpyrifos remained in soil plot 1 and 34.4 % in soil plot 2.
The percentages for 3,5,6 trichloropyridinol were 4.7 % in soil plot 1 and 7.8
% in soil plot 2. The percentage from average evaporation loss of chlorpyrifos
was 59.2 % from plot 1 and 58.2 % from plot 2. After the second year in
1991, 17.2 % remained in soil plot 1 and 15.6 % in the soil plot 2. The
percentages for 3,5,6 trichloropyridinol were 6.3 % in soil plot 1 and 4.7 % in
soil plot 2. The average percent evaporation loss were 69.3 % from plot-1 and
57.0 % from plot 2. The average potential distribution of chlorpyrifos was
calculated at the average wind speed and height in 1990 and 1991 (Figure 6).

Using the minimum wind speed (1 kph) assumption, the average
evaporation loss from the two plots was 13.0 % in 1990 and 13.8 % in 1991

at the average height. The effect of wind speed on the evaporation loss of

61

chlorpyrifos is shown in table 13. The evaporation loss was also calculated at
the maximum wind speed and the average height. The evaporation loss was
higher in the second year than the first year which may be due the higher
concentration in the compartment due to the carry over from the first year or
due to the different weather conditions such as the wind speed, temperature,
or humidity. The effect of height had a large effect on the evaporation loss was
a major factor in the calculation of total loss (Table 13). The volatilization loss
measured at 15 cm was higher than at 200 cm. For average calculation, a
column of air from the soil surface up to 200 cm which was close to the roof
of the facility, was taken into consideration. Therefore average evaporation loss
at 107.5 cm (average of 15 cm and 200cm) was employed for the calculations.

The loss due to volatilization of chlorpyrifos was the highest route of
dissipation from the soil degradation compartments.The high volatilization loss
was due to its high water solubility. Henry’s law constant for any pesticide of
less than 2.5 X 10'5 is nondimensional Henry’s law and therefore evaporation
loss control by water evaporation and vapor movement across the laminar layer
at the soil/air boundary (Glotfelty et al 1989). Chlorpyrifos Henry’s law constant
is 4.2 X 10‘6 and therefore dose not obey Henery's law . 0n the other hand the
hydrolysis product 3,5,6-trichloropyridinol (TAP) gave the lowest route of
dissipation and may be, due to the fact that, the soil pH was low or a low
population of microorganisms was present. The pathway of chlorpyrifos

degradation in soil involves both chemical and microbial processes. The major

62

products of degradation have been identified as the hydrolysis product 3,5,6-
trichloropyridinol (TAP), the secondary metabolite 3,5,6-trichloro-2-
methoxypyridine (TCMP) (Racke and Coats 1990) and eventually C02 resulting
from mineralization of the aromatic ring (Racke and Coats 1988). The rapid
hydrolysis of chlorpyrifos in the problem soils may be partially attributed to the
high pH of these soils (8.0-8.1) (Racke 1990). Chlorpyrifos is strongly sorbed
in soil, especially from solution to the sorbed phase which is much less

susceptible to microbial uptake and degradation (Racke and Coats 1990).

   

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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__9__9_A|-A Hl- RM

Alachlor (54.1 g) was applied to each soil degradation compartment (plot
1 and plot 2) three times a year for two years. A total weight of 162.3 g was
applied in the first year and 324.6 9 total for two years in each plot. The
percent distribution of alachlor in 1990 in the soil compartments (plot 1 and plot
2) was determined by calculating the percent of the residues remaining in the
soil, the percent of 2,6 diethylaniline which isthe major metabolites of
alachlor, and the percent of average evaporation loss of alachlor at the average
wind speed and average height (Table 14). After the first year in 1990, 23.3
% of alachlor remained in soil plot 1 and 13.3 % in soil plot 2. The percentages
for 2,6 diethylaniline were 20.3 % in soil plot 1 and 15.0 % in soil plot 2. The
percentage from average evaporation loss of alachlor was 86.4 % from plot 1
and 79.8 % from plot 2. After the second year in 1991, 20.8 % remained in
soil plot 1 and 25.0 % in the soil plot 2 (Table,14). The percentages for 2,6
diethylaniline were 9.2 % in soil plot 1 and 9.6 % in soil plot 2. The average
percent evaporation loss were 109.0 % from plot 1 and 116.2% from plot 2.
The average potential distribution of alachlor was calculated at the average
wind speed and height in 1990 and 1991 (Table 15).

Using the minimum wind speed (1 kph) assumption, the average
evaporation loss from the two plots was 24.2 % in 1990 and 18.4 % in 1991

at the average height. The effect of wind speed on the evaporation loss of

7O

alachlor is shown in table 15. The evaporation loss was also calculated at the
maximum wind speed and the average height (Table 15). The evaporation loss
was higher in the second year than the first year which may be due the higher
concentration in the compartment due to the carry over from the first year or
due to the different weather conditions such as the wind speed, temperature,
or humidity. The effect of height had a large effect on the evaporation loss was
a major factor in the calculation of total loss (Table 14). The volatilization loss
measured at 15 cm was higher than at 200 cm. For average calculation, 3
column of air from the soil surface up to 200 cm which was close to the roof
of the facility, was taken into consideration. Therefore average evaporation loss
at 107.5 cm (average of 15 cm and 200cm) was employed for the calculations.

The volatilization loss of alachlor was the primary route of dissipation
in the soil degradation compartments. The high volatilization loss was due to
its high water solubility and is reflected in the nondimensional Henry’s law
constant. The Henry’s law coefficient for alachlor is 3.23 x 10‘8 and, therefore,
evaporation loss is control by water evaporation and vapor movement across
the laminar layer at the soil/air boundary (Glotfelty et al 1989). On the other
hand the major metabolite 2,6—diethylaniline gave the lowest route of dissipation
because. Microbial degradation has been reported to be the major means of
destruction of chloroacetanilide pesticides in soils (Beestman and Deming,
1974). The degradation of alachlor by the soil fungus Chaetomium globosum

has been extensively studied and a number of metabolites have been identified

71
(Tiedje and Hagedorn 1975). Chou (1977) found that 2-chloro-2’,6’-

diethylaniline and 1-(ch|oroacety|)-2,3—dihydro-7-ethylindole was produced in
soil from alachlor. Mineralization in soil suspension was tested on soils that had
received alachlor in the field and 7.3% of the alachlor at a lower concentration
was mineralized in Lima—Kendaia silt loam (Novick 1986). A small percentage
of the ring carbons of alachlor was converted to CO2 under aerobic conditions
during the 30-day period. 2,6-diethylaniline accumulated in relatively'small
amounts during alachlor degradation probably due to its subsequent metabolism
and these findings are consistent with 2,6-diethylaniline being a major

intermediate in the alachlor degradation pathway (Tiedje and Hagedorn 1975).

 

 

 

 

 

 

 

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78

SIMAZINE (PRINQEP)

Simazine (145.3 g) was applied to each soil degradation compartment
(plot 1 and plot 2) three times a year for two years. A total weight of 435.9 g
was applied in the first year and 871.8 9 total for two years in each plot. The
percent distribution of simazine in 1990 in the soil compartments (plot 1 and
plot 2) was determined by calculating the percent of the residues remaining in
the soil, the percent of 2 6 diethylamine-4—hydroXy-s-triazine which is the major
metabolites of simazine, and the percent of average evaporation loss of
simazine at the average wind speed and average height (Table 16). After the
first year in 1990, 23.7% of simazine remained in soil plot 1 and 22.7 % in soil
plot 2. The percentages for 2,6 diethylamine-4—hydroxy-s-triazine were 0.46 %
in soil plot 1 and 0.46% in soil plot 2. The percentage from average
evaporation loss of simazine was 139.4 % from plot 1 and 171.3 % from plot
2 (Table 17). After the second year in 1991, 15.7 % remained in soil plot 1
and 17.6 % in the soil plot 2 (Table 16). The percentages for 2,6 diethylamine-
4~hydroxy-s-triazine were 0.01 % in soil plot 1 and 0.01 % in soil plot 2. The
average percent evaporation loss were 153.6 % from plot 1 and 148.7 % from
plot 2. The average potential distribution of simazine was calculated at the
average wind speed and height in 1990 and 1991 (Table 17).

Using the minimum wind speed (1 kph) assumption, the average

evaporation loss from the two plots was 44.4 % in 1990 and 40.2 % in'1991

 

79

at the average height. The effect of wind speed on the evaporation loss of
simazine is shown in table 16. The evaporation less was also calculated at the
maximum wind speed and the average height (Table 17). The evaporation loss
was higher in the second year than the first year which may be due the higher
concentration in the compartment due to the carry over from the first year or
due to the different weather conditions such as the wind speed, temperature,
or humidity. The effect of height had a large effect on the evaporation loss was
a major factor in the calculation of total loss (Table 16). The volatilization loss
measured at 15 cm was higher than at 200 cm. For average calculation, a
column of air from the soil surface up to 200 cm which was close to the roof
of the facility, was taken into consideration. Therefore average evaporation loss
at 107.5 cm (average of 15 cm and 200cm) was employed for the calculations.

The volatilization loss of simazine gave the highest dissipation loss of
all the pesticides studied in the soil degradation compartments. The high
volatilization loss was due to its high water solubility and reflected in the
nondimensional Henry’s law constant. The Henry’s law coefficient for simazine
is 4.62 x 10"° and therefore evaporation loss is controlled by water evaporation
and vapor movement across the laminar layer at the soil/air boundary (Glotfelty

et al 1989).

 

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86

The field data showed that the evaporation loss was the dominant
dissipation route for all four of the pesticides. Volatilization was the most an
important route of pesticides loss from the waste disposal facility and far
exceeded any other degradation loss such as hydrolysis, oxidation or
metabolism. Field-measured volatilization losses were not precise because of
the wide fluctuation in wind speed, temperature and humidity during the week
and even during any given day. At best one can only approximate the
volatilization losses over long time periods and the amount of the potential error
is not known. It is very hard to get the exact evaporation loss because of the
wind speed and the air sampling height. To help eliminate variation in the wind
speed and the other factors, sampling the air every day would be the best way
but would lead to an exceeding large number of samples. A complex model
such as that proposed by Jury et al (1983) would be needed to adequately take
into account all the factors that influence pesticides volatilization from soil. The
presence of formulation components in water complicates the estimation of
pesticides volatilization from the compartments. As the soil-water increased the
volatilization rate of pesticides increased ( Woodrow 1991). The volatilization
rates of the pesticides in wet soils are higher than in dry soil. On days when the
soil surface became dry, the volatilization of the pesticides was greatly reduced

by increased adsorption of the pesticides onto the dry soil particles. Vapor

 

 

87

pressure, water solubility and soil organic carbon adsorption coefficient are
important factors in determining the magnitude of the evaporation loss. The
volatilization losses of a number of volatile, non polar pesticides were measured
by Glotfelty in 1984, after their surface application to fallow soil. The
volatilization rates were more rapid from moist soil than from dry soil ( Glotfelty
et al 1984). The rate of volatilization of pesticides from soil is controlled by a
number of intrinsic factors that depend upon properties of the chemical and of
the soil (Glotfelty et al 1989). Pesticides in the soil solution obey Henry's law
(Spencer 1970). Spencer therefore concluded that a knowledge of Henry's law
coefficients and soil-water adsorption isotherms could be used to predict
pesticides volatility from soil. An empirical rate expression developed by Swann
et al 1982 which is appropriate to soil surface applications. The volatilization
rate K" is given by this equation:
KV = Q (P/Koc 8)
Where
P = Vapor pressure (mmHg)

Kc,c = the soil adsorption coefficient (organic basis)

8 = the water solubility

O = the empirically determined coefficient = 4.4X107.
Volatilization of compounds for which the nondimensional Henry's law
coefficient is much less than 2.5X1O'5 is controlled by water evaporation and

by vapor movement across the laminar layer at the soil-air boundary (Jury et al

 

88

1983). This occurs because the rate of movement of these compounds to the
soil surface with evaporating water exceeds their rate of volatilization from the
surface. After a period of time, volatilization of these more soluble, less volatile,
chemicals should become constant because they accumulate at the surface.

The data showed a relationship between evaporation loss and water
solubility for the nondimensional Henry’s law pesticides (Figure 20).
Chlorpyrifos, alachlor and simazine have Henry’s law constant lower than 2.5
X 10'5 (Table 18) and the lower the number of Henry's law constant the
higher evaporation loss due to the higher water solubility (Figure 21). The
chlorpyrifos showed a lower value of evaporation loss than alachlor. Simazine
exhibited the highest value for evaporation loss. The vapor pressure of
chlorpyrifos is higher than alachlor and simazine, however, simazine showed the
highest evaporation loss due to the higher water solubility. However, simazine
has the lowest vapor pressure. The data showed that the higher of the
pesticides water solubility, the higher the evaporation loss (Table 18).

The average potential dissipation of the selected pesticides were used in
study in 1990 and 1991 were 66.9 % and 67.3 % respectively for endosulfan
I + II, 69.9 % and 81.5 % for chlorpyrifos, 84.7 % and 84.2 % for alachlor
and 87.1 and 90.0 % for simazine. The pesticides wastes disposal facilityat
Michigan State University was a good method for the dissipation of all four of

the pesticides that were studied.

 

 

 

 

 

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TABLE 19. THE AVERAGE POTENTIAL DISSIPATION OF THE SELECTED
PESTICIDE USED IN THE STUDY OF THE FENNVILL. MICHIGAN
WASTE DISPOSAL FACILITY IN 1990 AND 1991

l Pesticides % dissipation I

 

 

 

 

 

1990 1991
Endosulfan l + II 66.9 67.3
Chlorpyrifos 69.9 81.5
Alachlor 84.7 84.2
Simazine 87.1 90.0

 

 

 

 

 

94

 

CHAPTER 4

SUMMARY AND CONCLUSIONS

96

SUMMARY AND CONCLUSIONS

Dilute pesticide wastes resulting from cleaning and rinsing of used
containers, spray tanks, equipment used for pesticide applications and
overestimating the amount needed for a spray operation. For such operations,
safe facilities and procedures are essential to degrade the wastes and protect
human health and the environment . The waste disposal facility at Michigan
State University was an adequate method for the dissipation of dilute pesticide
wastes. Also the inground soil degradation compartment is environmentally safe
because it has a concrete bottom liner and concrete walls. In addition, no
pesticides residues were detected in the drainage tile under the facility after the
two years study.

Volatilization loss was the dominant dissipation route for endosulfan l and
II, chlorpyrifos, alachlor, and simazine. The average potential dissipation of the
selected pesticides used in the study in 1990 was between 66.9 % and 87.1
% for endosulfan and simazine respectively. In 1991 the dissipation was
between 67.3 % for endosulfan and 90.0 % for simazine. water in a soil is
essential for effective pesticides dissipation in a waste disposal system. Water
is important for volatilization and hydrolysis of pesticides.

The pesticides waste disposal facility at Michigan State University was a

good method for the dissipation of all four of the pesticides used in the study.

97

Degradation facilities should be developed which are simple to use, reliable and
inexpensive.

In order to maintain a reasonable level of safety, any pesticides waste
disposal facility should be monitored the groundwater under and around the
facility at least twice every year for any pesticides contamination. Moreover,
minimizing the pesticide wastes input should be consider by calculating the
exact amount of pesticides needed. Also the contamination of groundwater
from any waste facility can be avoided by improved design, construction,
operation, and maintenance. Design considerations should always include the
hydrogeology of the location, area to be served, and types of wastes. The use
of liners and covers, as well as collection and treatment of leachate further
reduce the potential for groundwater contamination. Therefore disposal of
pesticide wastes must be in accordance with the Federal Resource Conservation

and Recovery act, state and local regulations.

LITERATURE CITED

 

99

LITERATURE CITED

Alexander, M. 1967. The breakdown of pesticides in soil. In: N. C. Brady,
Agriculture and the Quality of our Environment. Am. Assoc.
Advan. Sci., Wash., D. C. pp. 331-342.

Atkins, P. R. 1972. The pesticide manufacturing industry: current waste
treatment and disposal practices. EPA-12020-FYE-O1/72, University of
Texas, Austin, Department of Civil Engineering, January. (Available
from National Technical Information Service (NTIS) as PB-211 129.

Bouchard, D, C., C. G. Enfield, and M. D. Piwoni. 1989. Transport processes
involving organic chemicals. In B. L. Sawhney and K. Brown (ed.)
Reaction and Movement of organic chemicals in soils. SSSA Spec.
Publ. 22. ASA and SSSA, Madson, WI. pp. 349-371.

Bouchard, D. C. and T. L. Levy. 1983. High-performance liquid
chromatographic detremination of hexazinone residues in soil and
water. J. Chrom. 720:396-401.

Baker, R. A. 1972. Pesticide usage and its impact on the aquatic
environment in the Southeast. Contract EPA 68-01-0118, Teledyne
Brown Engineering, Huntsville, Alabama, September. 435 p. (Available
from National Technical Information Service (NTIS) as PB-252 849.

Bingham, S. W. 1973. Improving water quality by removal of pesticide
pollutants with aquatic plants. Bulletin No 58, Virginia Polytechnic
Institute and State University, Blacksburg, Virginia, water Resources
Research Center. 94 p.

Bowman, M. C, M. S. Schechter and R. L. Carter. 1965. Behavior of
chlorinated insecticides in a broad spectrum of soil types. J. Agr. Food
Chem. 13: 360- 365.

Branham, B. E. and Wehner D. J. 1985. The fate of Diazinon applied to
thatched turf, Agronomy Journal, Vol. 77, January-February.

Bro—Rasmussen, E. Noddegaard and K. Voldum-Clausen. 1968. Degradation
of diazinon in soil. J. Sci. Food Agric. 19 : 278-281.

100

Cliath, M. M. and W. F. spencer. 1972. Dissipation of pesticides from soil by
volatilization of degradation products. I. Lindane and DDT. Environ.
Sci. Technol., 6 (10): 910- 914.

Cotham, W. E. and T. F. Bidleman. 1989. Degradation of malathion,
endosulfan, and fenvalerate in seawater and seawater/sediment
microcosms. J. Agric. Food Chem. 37: 824-828

Day, H. R. 1976. Disposal of dilute pesticide solutions. EPA/530/SW-519,
U.S. Environmental Protection Agency, Washington, DC, Office of
Solid Waste Management Programs. 18 p. (Available from National
Technical Information Service (NTIS) as PB-261 160.

Dillon A. P. 1981. "Pesticide disposal and detoxification processes
and Techniques"; Noyes Data Corporation: Park Ridge, NJ; part II
Donaldson, W. T. (1992). The role of property-reactivity relationships
in meeting the EPA’s needs for environmental fate constants.
Environmental Toxicology and Chemistry. Vol. 11, pp. 337-891

Ferguson, T. L. 1975. Pollution control technology for pesticide formulators
and packagers. EPA/660/6-74/094, National Agricultural Chemical
Environmental Quality, January. 142 p. (Available from National
Technical Information Service (NTIS) as PB-241-001).

Geswein, A. J. 1975. Liners for land disposal sites: an assessment. EPA
report SW-137, p. 66. wash. D. C.

Getzin, L. W. 1968. Persistence of diazinon and Zinophos in soil:effects of
autoclaving, temperature, moisture, and acidity. J. Econ. Entomol.
61 (6) 1560-1565.

Ghassemi, M., and S. Ouinlivan 1975. A study of selected landfills designed
as pesticide disposal sites-Distributed by Nat. Tech. Inf. service PB
250 717,P. 131.

Ghassemi, M., S. C. Ouinlivan and H. R. Day 1976. Landfills for pesticide
waste disposal. Environ. Sci. Technol., 10 (13): 1209- 1214.

Glotfelty, D. E., A. W. Taylor, B. C. Turner, and W. H. Zoller. 1984.
Volatilization of surface-applied pesticides from fallow soil. J. Agric.
Food. Chem. 32:638-643.

101

Glotfelty, D. E., M. M. Leech, J. Jersey, and A. W. Taylor. 1989.
Volatilization and wind erosion of soil surface applied atrazine,
simazine, alachlor, and toxaphene. J. Agric. food chem. 37: 546-551.

Gray, R. A. and A. J. Weierich. 1965. Factors affecting the vapor loss of
EPTC from soils. Weeds 13: 141-147.

Gruber, G. l. 1975. Assessment of Industrial hazardous waste practices,
organic chemicals, pesticides, and various explosive industries.
Distributed by Nat. Tech. lnf.service PB 251-307, various paging.
Spring field Va.

Gomaa, H. M. and S. D. Faust.1972. Chemical hydrolysis and oxidation of
parathion and paraoxon in aquatic environment. S. D. Faust, ed.
Advances in Chemistry Series 111, American Chemical Society,
Washington, D. C. pp. 189-209.

Goring, C. A. I.,D. S. Laskowski, J. W. Hamaker,and R. W. Meikle. 1975.
Principles of pesticides degradation in soil. In: Environmental Dynamics
of pesticides R. Haque and V. H. Freed, eds. Plenum press, New
York. pp 13-172.

Guerin, T. F., W. L. Stephen, and I. R. Kennedy. 1992. Efficient one-step
method for the extraction of cyclodiene pesticides from aqueous
media and the analysis of their metabolites. J. Agric. Food Chem. 40:
2309-2314.

Guerin, T. F., and I. R. Kennedy. 1992. Distribution and dissipation of
endosulfan and related cyclodienes in sterile aqueous systems:
Implication for studies on biodegradation. J. Agric. Food Chem. 40:
2315-2323 ’

Gunner, H. B., and B. M. Zuckerman. 1968. Degradation of diazinon by
synergistic microbial action. Nature 217, 1183-1184.

Hall, 0.; J. Baker; P. Dahm; L. Freiburger; G. Gorder; L. Johnson; G. Junk
and F. Williams.1981. Safe Disposal Methods for Agricultural
Pesticide waste, U.S. EPA report 600/2-81-074, NTIS Accession PB
81 1975 .

Hall C. V. 1984. "Pesticide Waste Disposal in Agriculture", Treatment and
Disposal of Pesticide Waste. Raymond F. K.,ed and James N. S. ed,
ACS Spmposium Series 259, Washington, D.C.

102

Haque, R‘. and V. H. Freed. 1974. Behavior of pesticides in the environment:
"Environmental chemodynamics." Residue Reviews, 53:89-116.

Harris, C. R., and E. P. Lichtenstein 1961. Factors affecting the
volatilization of insecticidal residues from soils. J. Econ. Entomol.
54: 1 038-1 045.

Hayes, W. J. Jr. 1981. Toxicology of pesticides. The Williams and
Wilkins Co., Bltimore, MD. ‘

Helling, C. S. 1971 Pesticide mobility in soils I, II, and Ill. Parameters of
thin-layer chromatography. Soil Sci. Soc. Amer. Proc., 35:732-748.

Helling, C. S., P. C. Kearney and M. Alexander. (1971). Behavior of
Pesticides in Soils. Adv. Agron., 23:147-241.

Hil, D. W., and P. L. McCarty. 1967. Anaerobic degradation of selected
chlorinated hydrocarbon pesticides J. Water Pollut. Contr. Fed.
39:1259-1277. '

Igue, K. W. J. Farmer, W. F. Spencer and J. p. Martin.1970. Volatility of g
organochlorine insecticides from soils. Soil Sci. Soc Amer. Proc.
(Manuscript submitted to editor).

Jury, W. A.., W. J. Farmer, and W. F. Spencer. 1984. Behavior assessmet
model for trace organics in soil: ll. Chemical classification and
parameter sensitivity. J. Environ. Dual. 13:567-572.

Jury, W. A., W. F. Spencer, and W. J. Farmer. 1983. Behavior assessment
model for trace organics in soil: l. Model description.

Jury, W. A., R. Grover, W. F. Spencer and W. J. Farmer. 1980. Modeling
vapor losses of soil-incorporated triallate. Soil Sci. Am. J. 44:445-
450.

Junk G. A. and J. J. Richard. 1984. "Pesticide disposal sites: Sampling
and analyses", Treatment and Disposal of Pesticide Wastes.
Raymond F. K., ed and James N.S.ed, ACS Spmposium Series 259,
Washington, D. C.

Kaufman, D. D., J. R. Plimmer, P. C. Kearney, J. Blake and F. S. Guardia.
1968. Chemical vs. microbial decomposition of amitrol in soil. Weed
Science 16: 266-272.

103

Kaufman, D. D. and J. Blak. 1970. Degradation of atrazine by soil fungi. Soil
Biol. Biochem. 2: 73-80.

Kearney, P. C., P. J. Sheets and J. W. Smith. 1964. Volatility of seven
s-triazines. Weeds 12: 83-87.

Klein, S. A. 1974. An evaluation of the accumulation, translocation, and
degradation of pesticides at land waste water disposal sites.
Distributed by Nat. Tech Inf. service AD/A-006-551.p. 235.
Springfield, Va.

Konrad, J. G., D., D. E. Armstrong, and G. Chesters. 1967. Soil
degradation of diazinon, a phophorothioate insecticide. Agron. J. 59:
591- 594.

Lande, S. S. 1981. "Identification and description of chemical
deactivation/detoxification methods for the safe disposal of selected
pesticides," NTIS PB-285, 208, Spring filed, VA.

Lichtenstein, E. P. and K. R. Schulz. 1960. Epoxidation of aldrin and
heptachlor in soils as influenced by autoclaving, moisture, and soil
types. J. Econ. Entomol. 53: 192-197.

Lichtenstein, E. P. 1970. Rate movement of insecticides in and from soils.
Fate and movement of insecticides in and from soils. In pesticides in
the soil: Ecology, degradation and movement. Internat. Symp.
Michigan State University Symposium, East Lansing.

Lichtenstein, E. P. and K. R. Schulz. 1964. The effects of moisture and
microorganisms on the persistence and metabolism of some
organophosphotus insecticides in soils with special emphasis on
parathion. J. con. Entomol. 57: 618-627.

Lichtenstein, E. P. and K. R. Schulz. 1961. Effect of soil cultivation, soil

surface and water on the persistence of residues in soils. J. Econ.
Entomol. 54: 517-22.

Lichtenstein, E. P., C. H. Mueller, G. R. Myrdal and K. R. Schulz. 1962.
Vertical distribution and persistence of insecticidal residues in soils as
influenced by mode of application and a cover crop. J. Econ. Entomol.
55: 215-19.

 

104

Macalady, D. L., and N. L. Wolfe. 1983. New perspectives on the hydrolytic
degradation of the organophosphorothioate insecticide chlorpyrifos. J.
Agric Food Chem. 31: 1139-1147.

Macalady, D. L., and N. L. Wolfe. 1985. Efects of sediment sorption and
abiotic hydrolyses. 1. Organophosphorothioate esters.

Majewski M. S., M. McChesney, and J. N. Seiber. A field comparison of two
methods for measuring DCPA soil evaporation rates. Enviro. Tax. and
Chem. 10: 301-331.

Matsumura, F., G. M. Bouch and A. Tai. 1968. Breakdown of dieldrin in the
soil by a microorganism. Nature 219: 965-967.

Munakata, K. and M. Kuwahara. 1969. Photochemical degradation products
of pentachlorophenol. Residue Reviews 25: 13-23.

Munnecke, D., H. R. Day, and H. W. Trask. 1976. Review of pesticide
disposal research. EPA/530/SW-527, U.S. Environmental Protection
Agency, Washington, D. C., 76 p.

Nash, R. G. (1983). Comparative volatilization and dissipation rates of
several pesticides from soil, J. Agric. Food chem. 31: 210-217. -

Novick, N. J., R. Mukherjee, and M. Alexander. 1986. Metabolism of
alachlor and propachlor in suspensions of pretreated soils and in
samples from ground water aquifers. J. Agric. Food Chem. 34: 721-
725.

Paris, D. F., D. L. Lewis, and N. L. Wolfe (1975). Rates of degradation of
malthion by bacteria isolated from aquatic system. Environ. Sci.
Teechnol., 9(2):135-138.

Parochetti, J. V. and G. F. Warren. 1966. Vapor losses of IPC and CIPC.
Weeds14: 281-285.

Pesticides in soil and water. 1974. Soil science Society of America, INC.,
Publisher madison, Wisconsin USA.

Pesticides Minimizing the Risks. 1987. American Chemical Society,
Washington,D.C.

105

Pike, D. R., Colwell, C. 1984. 1982 lllinoi’s major crop pesticide use survey
report. (Illinois Pesticide Impact Assessment Program Bulletin).
Carbondal: department of Agronomy and Entomology. University of
lllionois.

Piotike, H. B. and G. Chester. 1973. Pesticide-Sediment-Water
interaction. J. Environ. Oual., 2 (1) (1973) 29-45.

Racke, K. D., and J. R. Coats. 1988. Comparative degradation of
organophosphorus insecticides in soil: specificity of enhanced
microbial degradation. J. Agric. Food Chem. 36: 193-199.

Racke,K. D., D. A. Laskowski, and M. R. Schultz. 1990. Resistance of
chlopyrifos to enhanced biodegradation in soil. J. Agric. Food Chem.
38:1430-1436.

Raymond, F. K. and N. S. James. 1984. Treatment and disposal of pesticide
waste. American Chemical Society. Residue Reviews vol. 64.
Springer-verlag New York Heidelberg Berlin.

Rima, D. R (1967). Potential contamination cf the hydrologic
environment from the pesticide waste dump in hardeman county,
Tennessee. USGS water Resource Division. Unpublished open
report to Federal water pollution control Board, P.41-Wash. D. C.

Sanborn, J. R., B. M. Francis, and R. L. Metcalf. 1977. The Degradation of
Selected Pesticides in Soil: A Review of the Published Literature.
Municipal EnvironmentalResearch Laboratory, Cincinnati, Ohio,
EPA/600/9-77/022, 635 p. (Available from the National Technical
Information Service as PB—272- 353).

SCE Engineers. 1979. Disposal of Dilute pesticide Solution,
NTIS Report PB-297 985.

Shih, C. C.; D. F. Dalporto. 1988. "Handbook for pesticides disposal by
common chemical methods" NTIS PB-252 864, spring field, VA.

Shuman, F. L.; B. J. Stojanovic, and M. V. Kennedy. 1972. Engineering
aspects of the disposal of unused pesticides, pesticide wastes, and
pesticide containers. J. Environ. Oual. 1,” 66 (1972).

Smith, R. T. ;K. Atkinson. 1975. " Techniques in Pedology"; Urwin Bros.
Ltd., The Greshorn Press.

106

Spencer, W. F; M. M. Cliath, and W. J. Farmer. 1969 c. Vapor density of
soil-applied dieldrin as related to soil water content, temperature and
dieldrin concentration. Soil Sci. Soc. Amer. Proc. 33: 509-511.

Spencer, W. F. 1970. Distribution of pesticides between soil, water and air.
p. 120-128. In pesticides in the soil: Ecology. degradation and
movement. Michigan State University. East Lansing.

Spencer, W. F. and M. M. Cliath. 1970 b. Desorption of lindan from soil as
related to vapor density. Soil Sci. Soc. Amer. Proc. 34: 574-578.

Spencer, W. F. and M. M. Cliath. 1973. Pesticide volatilization as related to
water loss from soil. J. Environ. Oual., 2(2):284-289.

Spencer, W. F., and M. M. Cliath. 1974. Factors affecting vapor loss of
trifluranlin from soil. J. Agric. Food. Chem. 22:987-991.

Spencer, W. F. and M. M. Cliath 1975. Vaporization of chemicals. In: '
Environmental Dynamics of Pesticides. R. Haque and V. H. Freed, eds.
plenum press, New York. pp. 61-78.

Straus, M. A. 1977). Hazardous waste management facilities in the United
States-1977.EPA/530/SW-146.3, Environmental Agency, Washington,
D.C., Hazardous Waste Management Division, Office of Solid Waste.
59 p.

Technologies and Management Strategies for Hazardous Waste Control.
1983. Congress of the United States office of Technology Assessment
Washington, D. C. 20510.

Tiedje J. M. and M. L. Hagedorn. 1975. Degradation of alachlor by a soil
fungus, Chaetomium globosum. J. Agric. Food Chem. 23: 77-81.

Tu, C. M. (1970) Effect of four organophosphorus insecticides on microbial
activities in soil. Applied microbiology 19: 479-484.

Tu. C. M., J. R. W. Miles, and C. R. Harris. 1968. Soil microbial degradation
of aldrin. Life Sciences 7: 311- 322.

Turner, 8. C., and D. E. Glotfelty. 1977. Field air sampling of pesticide
vapors with polyurethane foam. Anal. Chem. 49:7-10.

107

U.S. Environmental protection Agency 1974. Pesticides and Pesticide
Containers, Regulation for Acceptance and Recommended Procedures
for Disposal and Storage. Federal Register, 39 (85):15236-15241,
May 1.

Wainwright, M. 1978. A review of the effects of pesticides on microbial
activity in soils. J. Soi Sc., 29(3): 287-98.

Waliszewski S. M. and G. A. Szymczynski. 1985. Inexpensive, precise
method for the determination of chlorinated pesticide residues in soil,
Journal of Chromatography, 321 (1985) 480-483.

Wasserstrom, R. F.; R. Willes. 1985. Field Study: U.S. farm workers and
Pesticide Safety (World Resources Institute, study 3).

Winterlin W. L.; S. R. Schoen and C. R. Mourer. 1984. "Disposla of
Pesticide wastes in Lined Evaporation Beds", Treatment and Disposal
Pesticide wastes, Raymond F. K.,Ed and James N. 8., Ed, ACS
Symposium series 259/ Washington, D. C.

Woodland, R. G., M. C. Hall and R. R. Russel. 1965. Process for disposal
of chlorinated organic residues. J. Air Poll. control Assoc. 15,56.

Wooddrow J. E., M. M. McChesney, and J. N. Seiber. 1990. Modeling the
volatilization of pesticides and their distribution in the atmosphere.
Long Range Transport of Pesticides. Kurtz, D. A. Ed. Lewis publishers,
Chap. 5, 61-81.

Zabik, M. J. and L. O. Ruzo. 1981. Factors affecting Pesticide
Photodecomposition Studies. In Test Protocols for Environemental
Fate and Movement for Toxicants, Proc. Symp. 94th Ann. Meeting
Assoc. Off. Anal. Chem., Washington D. C., p. 20-27.

Zabik, M. J. 1983. " Photochemistry of Pesticides", Comprehensive insect
physiology biochemistry and pharmacology. Kerkut G. A., Ed and
Gilbert L. l., Ed, Pergamon Press, Vol. 12 (776-805).

 

 

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