REMOVAL OF ENDOCRINE DISRUPTING COMPOUNDS IN WATER RECLAMATION SYSTEMS – EFFICACY OF CONVENTIONAL UNIT OPERATIONS

The scope of this study was to investigate occurrence and fate of endocrine disrupting activity in water reclamation systems and the efficacy of conventional unit operations in removing this activity. Target compounds for this study were selected based on their relevance for non-potable and potable water reuse systems, their occurrence in wastewater effluents and the aquatic environment, and their fate in natural and engineered systems. The study employed a three-pronged analytical approach using enzyme-linked immunosorbent assays (ELISA) in concert with gas chromatography mass spectroscopy (GC/MS) analysis and bioassays as screening tools for endocrine disrupting activity. Bioassays were conducted to assess estrogen, androgen, and thyroid active compounds. This paper reports on findings from a comprehensive literature review on occurrence and fate of endocrine disrupting compounds during wastewater treatment and preliminary results from field studies conducted as part of this study. The study examined field samples from 12 water reclamation facilities in the United States employing different unit operations and reuse applications. The wastewater treatment processes selected include biotowers; activated sludge (no or partial nitrification, nitrification/denitrification), biological phosphorus removal, and chemical phosphorus removal; as well as tertiary filtration (granular media), disinfection (chlorination, UV); adsorption (activated carbon); membranes (microfiltration/reverse osmosis); constructed wetlands; and soil-aquifer treatment (SAT).