There is an increasing public concern over the potential health effects and environment impact caused by emerging organic contaminants that enter natural aquatic systems as a result of various human activities. Emerging contaminants span a wide range of compounds, which were designed to offer improvements in different aspects of human life. Among this class of emerging pollutants carbon-based nanoparticles, are group of chemical compounds that attracts attention due to their unique chemical, physical and electronic properties. The wider application of carbon nanoparticles has been impeded by their low solubility in polar liquids and by their strong tendency to aggregate due to hydrophobic-hydrophobic interactions. Contradictory data on toxicity of carbon nanomaterials to eukaryotic and prokaryotic organisms may also affect public perception regarding these new chemicals. In this study the cytotoxicity and epigenetic toxicity of single-walled carbon nanotubes (SWCNTs) dispersed in water using a range of natural and synthetic dispersants and derivatized fullerene nanoparticles (nC60) subjected to three treatment schemes (ozonation only, chlorination only, and sequential ozonation/chlorination) were evaluated by three independent methods: neutral red dye uptake and gap junction intercellular communication bioassays with rat liver epithelia cells (WB-F344 cell line) and colony forming units counting with E. coli. When the dispersant itself was non-toxic, no losses of E. coli and WB-F344 viability upon their exposure to dispersed SWCNTs were observed. The cell membrane, lysosomes, and intercellular gap junction communication channels remained unaffected in the presence of nC60 or its derivatives. No effect on the ability of E. coli to grow and form a colony was found after cells were added to nC60 suspensions. Oxidized nC60 aggregates were also characterized in terms of their morphology, size and surface charge and functionality. The formation of C-Cl bonds on the surface of chlorinated fullerenes was detected. This is an important finding as it demonstrates that carbon nanomaterials can potentially be precursors for chlorinated carbon-based disinfection by-products. Pharmaceuticals are another class of emerging contaminants broadly used in human and veterinary medicine and in agriculture. In this study the hybrid ozonation - ceramic membrane filtration was evaluated for the removal of pharmaceutically active compounds and disinfection by-products precursors (DBPs) from surface waters with very different characteristics. This study demonstrated that under appropriate operating conditions the ozonation-ceramic membrane filtration could significantly improve water quality and reduce membrane fouling as compared to conventional filtration only. The concentration of model pharmaceuticals in permeate was reduced to below the detection limits. Significant reduction in total organic carbon, UV-254 absorbing compounds and DBPs formation potential was also achieved.
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