EVALUATION OF THE FATE OF SYNTHETIC AND NATURAL HORMONES IN A FULL MUNICIPAL WASTEWATER TREATMENT PLANT

The impact of a full-scale municipal wastewater treatment plant (WWTP), and each of the treatment units within the stream, on the removal of endocrine-disrupting compounds was evaluated by tracking three estrogenic compounds: 17-β-estradiol (E2, natural); estrone (E1, natural, metabolite of E2); and 17-α-ethinylestradiol (EE2, synthetic). The overall performance of the WWTP compared well with other plants, as 90.5% removal of E1+E2, and 76.4% removal of EE2 were observed. The activated sludge units reduced the concentration of E1+E2, and EE2 in the liquid phase by 88.2% and 44.6%, respectively. Additional removal of soluble phase estrogens (68% and 62% for E1+E2 and EE2, respectively) was observed in the equalization basin prior to UV disinfection. Although not statistically significant, the UV treatment process appeared to result in a slight increase in soluble phase estrogens. The aqueous phase of the tertiary lagoon sludge contained higher levels of estrogens compared to the lagoon influent. This was attributed to the possible de-sorption of particulate matter-bound estrogens during storage in the lagoon.