Zeng Qingling, Li Yongmei, Yang Shijia
State Key Laboratory of Pollution Control and Resources Reuse, College of Environmental Science and Engineering, Tongji University , Shanghai, China . ; College of Civil Engineering, Huaqiao University , Xiamen, Fujian, China .
Environ Eng Sci. 2013 Apr;30(4):161-169. doi: 10.1089/ees.2011.0400.
Estrogen in wastewater are responsible for a significant part of the endocrine-disrupting effects observed in the aquatic environment. The effect of sludge retention time (SRT) on the removal and fate of 17β-estradiol (E2) and 17α-ethinylestradiol (EE2) in an anaerobic-anoxic-oxic activated sludge system designed for nutrient removal was investigated by laboratory-scale experiments using synthetic wastewater. With a hydraulic retention time of 8 h, when SRT ranged 10-25 days, E2 was almost completely removed from water, and EE2 removal efficiency was 65%-81%. Both estrogens were easily sorbed onto activated sludge. Distribution coefficients () of estrogens on anaerobic sludge were greater than those on anoxic and aerobic sludges. Mass balance calculation indicated that 99% of influent E2 was degraded by the activated sludge process, and 1% remained in excess sludge; of influent EE2, 62.0%-80.1% was biodegraded; 18.9%-34.7% was released in effluent; and 0.88%-3.31% remained in excess sludge. Optimal SRT was 20 days for both estrogen and nutrient removal. E2 was almost completely degraded, and EE2 was only partly degraded in the activated sludge process. Residual estrogen on excess sludge must be considered in the sludge treatment and disposal processes. The originality of the work is that removal of nutrients and estrogens were linked, and optimal SRT for both estrogen and nutrient removal in an enhanced biological phosphorus removal system was determined. This has an important implication for the design and operation of full-scale wastewater treatment plants.
废水中的雌激素是造成水生环境中观察到的内分泌干扰效应的重要原因。通过使用合成废水的实验室规模实验，研究了污泥停留时间（SRT）对设计用于除磷的厌氧 - 缺氧 - 好氧活性污泥系统中17β - 雌二醇（E2）和17α - 乙炔雌二醇（EE2）的去除及去向的影响。在水力停留时间为8小时的情况下，当SRT在10 - 25天范围内时，E2几乎完全从水中去除，EE2的去除效率为65% - 81%。两种雌激素都很容易吸附到活性污泥上。雌激素在厌氧污泥上的分配系数大于在缺氧和好氧污泥上的分配系数。质量平衡计算表明，进水E2的99%通过活性污泥法降解，1%残留在剩余污泥中；进水EE2中，62.0% - 80.1%被生物降解；18.9% - 34.7%排放到出水中；0.88% - 3.31%残留在剩余污泥中。对于雌激素和营养物的去除，最佳SRT均为20天。在活性污泥法中，E2几乎完全降解，而EE2仅部分降解。在污泥处理和处置过程中必须考虑剩余污泥上残留的雌激素。这项工作的创新性在于将营养物和雌激素的去除联系起来，并确定了强化生物除磷系统中雌激素和营养物去除的最佳SRT。这对实际规模污水处理厂的设计和运行具有重要意义。
