The Occurrence and Fate of Endocrine Disrupting Compounds in Wastewater Treatment Plants in Israel

Tal Godinger, Zuckerberg institute for water research, Ben Gurion University, Jerusalem, Israel

Endocrine disrupting compounds (EDCs) are organic micropollutants found all over the world in different water bodies. These compounds have been found to alter the hormonal system of different organisms, including humans, and therefore considered to be an environmental risk. The use of treated wastewater (WW) for irrigation and direct discharge into streams, are the main pathway of EDCs into the environment. The objectives of this study were to examine EDCs occurrence in raw WW and measure their removal by wastewater treatment plants (WWTP). Therefore, six WWTPs were sampled in two sampling periods, during the winter and summer. Samples were taken along the treatment; after the primary, secondary and tertiary treatments. Sludge samples were also collected in most of the facilities. The extraction and analysis of WW samples was executed according to USEPA protocols. Solid phase extraction (SPE) was the method used for the extraction, using the appropriate solvents for the different compounds. Sludge samples were freeze-dried and then extracted in accelerated solvent extraction device (ASE). Finally, water and sludge samples were analyzed by GC-MS or LC-MS instruments. The most frequent EDCs in raw WW and treated WW were triclosan (TCS) and the natural estrogens, estrone and estriol. TCS was found to be the most resistant EDC for treatment in WWTPs. Nevertheless, TCS pose environmental risk from 1.55 µg/L and up, much higher than the levels detected in the treated WW. Estrone and estriol usually were eliminated from WW during secondary treatment. In general, the treatment methods used by the different WWTPs, achieved, in most cases, similar removal of EDCs. In sludge samples, the most common EDC was octylphenol, but TCS was found in the highest concentrations. Environmental risk assessment analysis using a risk quotient benchmark revealed that the tested EDCs in treated WW could pose a low-medium environmental risk.