Worldcongress2013.org

OCCURRENCE AND RISK ASSESSMENT OF PHARMACEUTICAL
SUBSTANCES IN THE GREAT LAKES BASIN
Merih Otker Uslua,b, Saad Jasima,b, Antonette Arvaia , Jatinder Bewtrab, Nihar Biswasb
aGreat Lakes Regional Office, International Joint Commission, Windsor, Ontario, Canada
bCivil and Environmental Engineering, University of Windsor, Windsor, Ontario, Canada
ABSTRACT
Pharmaceutical substances are used extensively to treat diseases in humans and animals. They are emerging pollutants in water and their presence in the environment is of growing concern worldwide. The continuous load of pharmaceutical substances into wastewater treatment plants (WWTPs) through human excrement as well as hospital and manufacturing plant effluents leads to a contamination of WWTP influents with pharmaceutical substances. Conventional WWTPs usually have limited success in completely removing pharmaceutically active substances, and as a result these are almost always detected in the WWTP effluents. Discharge of inefficiently treated WWTP effluents, surface runoff from the agricultural areas and irrigation with treated or untreated wastewater are the main sources for pharmaceutical contaminants in surface and ground waters that supply drinking water. Conventional drinking water treatment processes including coagulation, flocculation, sedimentation, filtration and chlorination have been demonstrated to be marginally effective in completely removing these The present study review the occurrence and potential risks of pharmaceutical substances in the wastewater treatment plants, natural waters and drinking water treatment plants served by the Great Lakes Basin (Canada and the USA) between the years of 2007–2011. Large number of pharmaceutical substances, including antiinflammatories, lipid regulators, anti-depressants, antibiotics, beta blockers, anti-epileptics, anti-hypertensions and stimulants in high ng/L concentrations, has been reported in the WWTP influents, suggesting the inefficiency of conventional treatment processes in the degradation of pharmaceutical compounds. Decreasing surface water concentrations have been observed with the distance downstream of the discharge point due to the dilution effect. Surface waters located around septic systems and agricultural areas have also been found to be contaminated with pharmaceutical substances. Carbamazepine, caffeine, its metabolite paraxanthine, ibuprofen, gemfibrozil and sulfamethoxazole have been frequently detected in surface waters. The number of occurrences of carbamazepine, ibuprofen, naproxen, gemfibrozil, bezafibrate, sulfamethoxazole and macrolide antibiotics in drinking water sources, at ng/L concentration ranges, has been quite high. Risk assessment of pharmaceuticals showed that the six of the detected pharmaceuticals, namely, venlafaxine, sulfamethoxazole, clarithromycin, erythromycin, carbamazepine and esterone exhibit a high environmental risk in Great Lakes WWTP effluents and surface waters. Inefficiency of conventional treatments in WWTPs on the complete removal of pharmaceutical substances and environmental risk posed by these substances has triggered the search for more advanced technologies. Advanced treatment technologies including activated carbon adsorption, ozonation, microfiltration/reverse osmosis or nanofiltration seem to be much more efficient in the elimination of most of the pharmaceutical substances compared to conventional treatments in wastewater and water treatment plants. However, among these technologies, membranes and activated carbon does not offer degradation of these compounds which are in fact transferred to another phase. Consequently, ozonation seems to be most promising method for the efficient transformation of pharmaceutical substances in water and wastewater treatment plants as it has many additional advantages, such as, disinfection, odor and taste control. Keywords: Ozone, Great Lakes, pharmaceutical, contamination, wastewater, drinking water, natural

Source: http://www.worldcongress2013.org/media/docs/abstracts/Jasim_2013_IOA-IUVA_World_Congress.pdf