Occurrence of estrogens and their removal by biological processes of sewage treatment

Abstract Estrogens are micropollutants that may harm aquatic organisms endocrine system. They enter water bodies mainly through domestic sewage. This paper aims to review the estrone, estradiol, estriol and ethinyl estradiol occurrence in untreated and treated sewage and surface water, as well as their removal efficiency through employment of different sewage biological treatment methods. The few studies carried out in Brazil show a significant concentration of these compounds in the reviewed sources, with a downward trend from raw to treated sewage. Aerobic systems, such as activated sludge, showed better results at removing the estrogens, mainly through adsorption by sludge. However, little is known about the degradation mechanisms of such compounds and the behavior of their conjugates. Therefore, biological processes of sewage treatment represent a barrier to the introduction of estrogens to the water bodies.

摘要 雌激素(Estrogens)是一类可损害水生生物内分泌系统的微污染物，其主要通过生活污水进入水体。本文旨在综述雌酮(Estrone)、雌二醇(Estradiol)、雌三醇(Estriol)与炔雌醇(Ethinyl Estradiol)在未处理污水、处理后污水及地表水中的赋存状态，同时探讨采用不同污水生物处理工艺对这类物质的去除效能。目前巴西开展的相关研究较为有限，但已有结果显示，上述化合物在被综述的水环境介质中浓度可观，且从原污水到处理后污水呈现浓度递减趋势。好氧系统(Aerobic systems，如活性污泥(activated sludge)工艺)对雌激素的去除效果更优，其主要去除机制为污泥吸附作用。然而，目前对这类化合物的降解机制及其结合态产物的行为特征仍缺乏深入认知。因此，污水生物处理工艺可作为阻断雌激素进入水体的有效屏障。