Hu Zhiqiang, Chandran Kartik, Grasso Domenico, Smets Barth F
Environmental Engineering Program, University of Connecticut, Storrs, CT 06269-2037, USA.
Water Res. 2004 Nov;38(18):3949-59. doi: 10.1016/j.watres.2004.06.025.
Stringent effluent discharge limits for nitrogen require development of assays to accurately and rapidly determine whether a wastewater stream will inhibit nitrification. The suitability of a short-term extant batch respirometric assay to predict nitrification inhibition by metals (Cu, Zn, Ni and Cd) in continuous flow reactors was evaluated. Linear metal partition coefficients were determined to be 78.42+/-2.46, 0.54+/-0.04, 0.05+/-0.01 and 0.60+/-0.01 L/g biomass COD in batch experiments (pH=7.5) for Cu, Zn, Ni and Cd, respectively. A mass-balance model, incorporating metal partitioning, adequately fit the metal concentration profiles in the continuous flow reactor during and after a 24-hour shock load. However, the short-term batch assays significantly underestimated observed inhibition in the continuous flow reactor. The underestimation was, most likely, due to slow kinetics of Zn, Ni and Cd internalization and an exacerbation effect due to continued metal exposure in the continuous flow reactor. The discrepancy in inhibition between batch and continuous systems was the largest for Cu, presumably due to its unique mode of action, which involves loss of cell membrane integrity. Hence, using results from short-term batch respirometric assays to infer responses in continuous flow reactors with longer exposure should be done with caution and must accommodate partitioning behavior and internalization kinetics.
严格的氮排放限值要求开发相关检测方法，以准确、快速地确定废水流是否会抑制硝化作用。评估了一种短期现有批次呼吸测定法预测连续流反应器中金属（铜、锌、镍和镉）对硝化作用抑制的适用性。在批次实验（pH = 7.5）中，铜、锌、镍和镉的线性金属分配系数分别确定为78.42±2.46、0.54±0.04、0.05±0.01和0.60±0.01 L/g生物量化学需氧量。一个纳入金属分配的质量平衡模型，充分拟合了连续流反应器在24小时冲击负荷期间及之后的金属浓度分布。然而，短期批次检测显著低估了连续流反应器中观察到的抑制作用。这种低估很可能是由于锌、镍和镉内化动力学缓慢以及连续流反应器中持续金属暴露导致的加剧效应。批次系统和连续系统之间抑制作用的差异对于铜来说最大，可能是由于其独特的作用方式，涉及细胞膜完整性的丧失。因此，使用短期批次呼吸测定法的结果来推断长时间暴露的连续流反应器中的响应时应谨慎，并且必须考虑分配行为和内化动力学。
