Facultad de Ingenieria Campus Morelos, National Autonomous University of Mexico, Paseo Cuauhnahuac 8532, Col. Progreso, Jiutepec, Morelos 62550, México.
Water Sci Technol. 2010;62(9):2183-9. doi: 10.2166/wst.2010.441.
The biological degradation of estrone (E1), estradiol (E2) and ethinylestradiol (EE2) was studied in batch experiments at typical concentration levels using nitrifying activated sludge from a membrane bioreactor (MBR). Since first-order, pseudo first-order and Monod-type kinetics were observed. Pseudo first order kinetic was reformulated using only the soluble concentrations S and assuming adsorption coefficient K(D) of the estrogens. For the adsorption coefficients K(D) determination, activated sludge from MBR was spiked with the respective target compounds and stirred. Finally, the water was analyzed. The K(D) values of estrogens ranged from 0.323 to 0.474 L/g. Greater than 98% of E1, E2 and EE2 were found to be removed in batch reactors. The measured data were linearly regressed giving R(2) values ranging from 0.748 to 0.990. According to these results, the biodegradation kinetics were adjusted to pseudo first-order assuming adsorption coefficient K(D) and Monod-type kinetic. The biodegradation rate constant k of the estrogens were: E1 and E2 > 78.52 L/g(VSS) d and 12.41 L/g(VSS) d for EE2. Monod-type kinetic indicates that these compounds are biodegradated by co-metabolism. E2 was oxidized into E1.
采用膜生物反应器（MBR）中的硝化活性污泥，在典型浓度水平下进行批式实验，研究雌酮（E1）、雌二醇（E2）和乙炔雌二醇（EE2）的生物降解情况。由于观察到了一级、拟一级和 Monod 型动力学。拟一级动力学是通过仅使用可溶性浓度 S 并假设雌激素的吸附系数 K(D)来重新制定的。为了确定吸附系数 K(D)，将 MBR 中的活性污泥与相应的目标化合物混合并搅拌。最后，对水进行分析。雌激素的 K(D)值范围为 0.323 至 0.474 L/g。在批量反应器中，发现超过 98%的 E1、E2 和 EE2 被去除。测量数据进行线性回归，得到的 R(2) 值范围为 0.748 至 0.990。根据这些结果，假设吸附系数 K(D)和 Monod 型动力学，将生物降解动力学调整为拟一级动力学。雌激素的生物降解速率常数 k 为：E1 和 E2 > 78.52 L/g(VSS) d 和 12.41 L/g(VSS) d，EE2 为 12.41 L/g(VSS) d。Monod 型动力学表明，这些化合物通过共代谢进行生物降解。E2 被氧化为 E1。
