Abstract: Nitrifier enriched culture (NEC) cultivated in laboratory and nitrifying activated sludge taken from STPs were used to biodegrade estrone (E1) and 17α-ethinylestradiol (EE2). The correlation between ammonia oxidation activity and estrogens biodegradation activity was investigated by varying initial ammonia concentration and inhibiting the activity of ammonia oxidizing bacteria (AOB) with allylthiourea. Estrogens biodegradation activity in NEC was significantly dependent on the activity of AOB, and the nitration of estrogens as well as biodegradation by heterotrophs was minimal. The co-metabolism of estrogens by AOB was identified. In NAS, estrogens biodegradation still happened with ATU inhibition, implying that AOB and heterotrophs cooperated to biodegrade E1 and EE2. However, the co-metabolism of estrogens by AOB remained the most efficient biodegradation pathway in NAS.

Key words: activated sludge, estrogens, biodegradation, ammonia oxidation activity

摘要： 采用驯化后的硝化菌富集培养物(NEC)及实际污水厂的硝化活性污泥(NAS)降解雌酮(E1)和17α-乙炔基雌二醇(EE2), 通过初始氨氮浓度的变化及氨氧化菌活性的抑制改变污泥氨氧化活性, 并考察氨氧化活性对雌激素降解活性的影响。结果表明, NEC中雌激素的降解活性主要来自氨氧化菌, 亚硝酸盐对雌激素的硝基化作用及异养菌的代谢作用均较弱, 氨氧化菌对雌激素的共代谢得到证实。在NAS中, 氨氧化菌抑制剂烯丙基硫脲并未完全抑制E1和EE2的降解活性, 表明雌激素降解由氨氧化菌与异养菌共同完成, 而氨氧化菌的共代谢降解显然更为高效。

关键词: 活性污泥, 雌激素, 生物降解, 氨氧化活性