Abstract
Experimental investigations on the biodegradation of endocrine disrupting chemicals (EDC) in the aerobic and anaerobic sludges were carried out. EDC concentrations were adjusted to the same levels of the influent derived from the actual sewage treatment plants or the domestic wastewater treatment facilities (Gappei-shori Johkasous). After 90% of 17 β-estradiol (E2) was adsorbed by the activated sludges, it declined to the value under the detection limit at 72 hours. Higher the MLSS concentration of sludges were, more adsorption of bisphenol A (BPA) and nonylphenol (NP) were obtained, and their removal efficiencies varied in the range of 72-99% and 59-90%, respectively. Biodegradation rates of E2, BPA and NP conformed to the first-order reaction model. However, the biodegradation of E2, BPA and NP was not caused by the anaerobic sludges. It was confirmed that mono-(2-ethylhexyl) phthalate, mono-butyl phthalate and phthalic acid were formed as the intermediates in the aerobic biodegradation of di-(2-ethylhexyl) phthalate and di-n-butyl phthalate.
