David A. Reckhow
Endocrine disrupting chemicals (EDCs) are natural or synthetic compounds that act like hormones in the endocrine system and disrupt the physiologic function of endogenous hormones. Although no standards concerning EDCs in drinking water have been established, there are rising concerns about the effects of EDCs in drinking water on human health.
The main objective of this study is to conduct bench scale experiments to investigate the effectiveness of conventional drinking water treatment processes at removing selected endocrine disrupting compounds (EDCs), pharmaceutical and personal care products (PPCPs) from municipal water supplies. It was also a goal of this work to provide utilities with information on likely removal of these compounds under a board range of water qualities and treatment scenarios.
Raw water used for this work came from 15 participating utilities, and each utility had at least one source water and treatment system. Samples were collected at different times of the year, and important water quality parameters, such as UV254, TOC and DOC were measured. The concentration of the target compounds in the raw water, travel blank, and treated water was also measured.
Overall, the treatment processes that include oxidation such as ozonation, chlorination and chloramination are the most effective processes resulting in around 80% to 100% of the target compounds removal. Chlorination alone is very effective at removing most of the target compounds that were studied. N-N-diethyltoluamide (DEET) and Tris (2 chloroethyl) phosphate (TCEP) are relatively resistant to all the treatment techniques that were tested (coagulation, ozonation, chlorination, chloramination and GAC/dual-media filtration).
However, filtration on adsorptive media was able to remove most of the DEET when the DEET concentration was low. This could be due to the result of adsorption on the GACmedia. The ozone-GAC biofiltration process is very effective at controlling and removing most target compounds.