Evaluation of Estrogenic Activity and Measurement of EDCs in Wastewater Treatment Plants

Correlations between estrogenic activity and DOC/UV260 ratio in wastewater treatment processes were investigated to propose a simple, reliable and comprehensive indicator for the presence of estrogenic substances. Contrary to this,when short-term bioassays such as the E-SCREEN, receptor binding and reporter gene expression assays are used for detecting estrogenic activity in the wastewater sample, they require a long time, at least a few days. The major factors contributing to the estrogenic activity were found to be 17β-estradiol (E2) and estrone (E1). A good relationship between the DOC/UV260 ratio and the concentration of estrogens (E1 and E2) in the effluent of the activated sludge process was found: the E2 concentration increased as the DOC/UV260 ratio increased while the E1 concentration decreased. The relative estrogenic activity and DOC/UV260 ratio showed a good correlation (R2 = 0.84) for all sewage samples except the ozonized samples in the sewage treatment plants. This study shows that the estrogenic compounds are hard to be mineralized by the conventional biological processes. Advanced oxidation processes are required to further remove estrogenic substances in the secondary effluent. By analysis of DOC and UV260, the estrogenic activity in the wastewater can be rapidly estimated.