No abstract

A study was conducted for about one year on the fate and behavior of estrogens, namely 17beta-estradiol (E2), estrone (E1), and estriol (E3) in an activated sludge process of a pilot scale plant supplied with domestic sewage. A simultaneous analytical method for these three substances using LC-MS/MS was developed and applied to sewage samples. The average removal of E2 was 94.7%, while that of E3 was 96.9%. In contrast, the average removal of E1 was relatively low at 69.2% with a maximum concentration of 55.4 ng/L detected in the treated water. The theoretical values of estrogenic activity calculated from the concentrations of each natural estrogen in treated water were found to correlate with the values of estrogenic activity measured by a yeast estrogen screening assay. The effect of E2 on estrogenic activity in influent was found to be high, while that of E1 in treated water was considerably higher. In batch treatment tests on E2, E2 turned into E1 immediately after being charged. After three hours of aeration, the values of both E1 and E2 were around threshold limits. It was determined from this that E1 and E2 were substances that could be degraded by biological treatment. As the removal of E2 was found to be sufficiently high at times, optimization of operational conditions based on E1 removal should be important for reducing estrogenic activity in treated water.

No abstract

Four sewage treatment plants based on an activated sludge process and a pilot scale plant for advanced sewage treatment located in Japan were evaluated for removal of estrogenic substances using in vitro recombinant yeast assay and chemical analysis. The results indicated that 17beta-estradiol (E2) significantly contributed to estrogen-like activity analyzed by yeast assay especially in secondary treated effluents. On the other hand, batch study showed that estrogen-like activity of spiked E2 was easily decreased by an activated sludge treatment. This result suggested that E2 concentrations measured by enzyme immunoassay (EIA) were interpreted as false positives in effluents, and that unknown estrogenic substances other than E2 might have contributed to estrogen-like activity in the secondary treated effluents. Further, in the pilot scale study, advanced sewage treatment processes such as a biological aerated filtration (BAF) process, an advanced oxidation process (AOP), were effective for the removal of those estrogenic activities contributed by unknown estrogenic substances in sewage secondary treated effluent.