Joss Adriano, Andersen Henrik, Ternes Thomas, Richle Philip R, Siegrist Hansruedi
EAWAG, Ueberlandstrasse 133, 8600 Dübendorf, Switzerland.
Environ Sci Technol. 2004 Jun 1;38(11):3047-55. doi: 10.1021/es0351488.
The removal of estrogens (estrone E1, estradiol E2, and ethinylestradiol EE2) was studied in various municipal wastewater treatment processes equipped for nutrient removal. A biological degradation model is formulated, and kinetic parameters are evaluated with batch experiments under various redox conditions. The resulting model calculations are then compared with sampling campaigns performed on differenttypes of full-scale plant: conventional activated-sludge treatment, a membrane bioreactor, and a fixed-bed reactor. The results show a > 90% removal of all estrogens in the activated sludge processes. (Due to the analytical quantification limit and low influent concentrations, however, this removal efficiency represents only an observable minimum.) The removal efficiencies of 77% and > or = 90% for E1 and E2, respectively, in the fixed-bed reactor represent a good performance in view of the short hydraulic retention time of 35 min. The first-order removal-rate constant in batch experiments observed for E2 varied from 150 to 950 d(-1) for a 1 gSS L(-1) sludge suspension. The removal efficiency of E1 and EE2 clearly depends on the redox conditions, the maximum removal rate occurring under aerobic conditions when E1 was reduced to E2. Sampling campaigns on full-scale plants indicate that the kinetic values identified in batch experiments (without substrate addition) for the natural estrogens may overestimate the actual removal rates. Although this paper does not give direct experimental evidence, it seems that the substrate present in the raw influent competitively inhibits the degradation of E1 and E2. These compounds are therefore removed mainly in activated sludge compartments with low substrate loading. Theoretical evaluation leads us to expect that diffusive mass transfer inside the floc (but not across the laminar boundary layer) appreciably influences the observed degradation rates of E1 and E2, but not of EE2.
在各种具备营养物去除功能的城市污水处理工艺中，对雌激素（雌酮E1、雌二醇E2和乙炔雌二醇EE2）的去除情况进行了研究。构建了生物降解模型，并通过在不同氧化还原条件下的批次实验评估了动力学参数。然后将所得的模型计算结果与在不同类型的全尺寸工厂进行的采样活动结果进行比较：传统活性污泥处理工艺、膜生物反应器和固定床反应器。结果表明，活性污泥工艺对所有雌激素的去除率均大于90%。（然而，由于分析定量限和进水浓度较低，这种去除效率仅代表可观测到的最小值。）鉴于固定床反应器的水力停留时间仅为35分钟，其对E1和E2的去除效率分别为77%和≥90%，表现良好。在1 gSS L(-1)的污泥悬浮液中，批次实验观察到E2的一级去除速率常数在150至950 d(-1)之间变化。E1和EE2的去除效率明显取决于氧化还原条件，当E1还原为E2时，在好氧条件下去除率最高。全尺寸工厂的采样活动表明，在批次实验（不添加底物）中确定的天然雌激素的动力学值可能高估了实际去除率。尽管本文没有给出直接的实验证据，但原进水所含的底物似乎竞争性抑制了E1和E2的降解。因此，这些化合物主要在底物负荷较低的活性污泥隔室中被去除。理论评估使我们预期，絮体内部（而非跨层流边界层）的扩散传质会显著影响所观察到的E1和E2的降解速率，但对EE2的降解速率没有影响。
