Department of Civil Engineering, University of Manitoba, Winnipeg, Canada.
Environ Technol. 2010 Oct;31(11):1263-9. doi: 10.1080/09593331003674549.
The degradation of 17beta-oestradiol (E2) and 17alpha-ethinyloestradiol (EE2) was investigated in an aerobic activated sludge system fed with synthetic wastewater. The effect of different solid residence times (SRTs) and nitrification inhibitors, such as allylthiourea (ATU), was studied in order to assess which group of microorganisms plays a significant role in the degradation of oestrogens. E2 was effectively converted into oestrone (E1) under all the conditions encountered in the nitrifying activated sludge system. The degradation of E2 obeyed first-order reaction kinetics; with an increase in SRT from 12 to 20 days, the degradation rate constant, k, decreased from 2.3 h(-1) to 0.47 h(-1). The removal of EE2 did not change significantly with the addition of ATU and at different SRTs. Only about 20% of EE2 was removed from the system, which demonstrated that EE2 was more recalcitrant than natural oestrogens. The results are supported by other recent studies, which suggest that co-metabolic degradation of EE2 and E2 by ammonia-oxidizing bacteria is not an important removal mechanism. The primary mechanism for E2 and EE2 degradation in activated sludge is most probably the activity of heterotrophic bacteria.
采用人工合成废水，研究了好氧活性污泥系统中 17β-雌二醇（E2）和 17α-乙炔基雌二醇（EE2）的降解情况。考察了不同固体停留时间（SRT）和硝化抑制剂（如烯丙基硫脲（ATU））对 EE2 降解的影响，以评估哪类微生物在雌激素的降解中起重要作用。在硝化活性污泥系统中遇到的所有条件下，E2 均有效地转化为雌酮（E1）。E2 的降解符合一级反应动力学；随着 SRT 从 12 天增加到 20 天，降解速率常数 k 从 2.3 h-1 降低到 0.47 h-1。添加 ATU 和不同 SRT 对 EE2 的去除没有明显影响。系统仅去除了约 20%的 EE2，这表明 EE2 比天然雌激素更难降解。这一结果得到了其他最近研究的支持，这些研究表明，氨氧化菌对 EE2 和 E2 的共代谢降解不是重要的去除机制。活性污泥中 E2 和 EE2 降解的主要机制很可能是异养菌的活性。
