Department of Civil and Environmental Engineering, Southern Methodist University, Room 203, 3101 Dyer Street, Dallas, TX 75205, USA.
Water Res. 2013 Sep 1;47(13):4383-90. doi: 10.1016/j.watres.2013.04.039. Epub 2013 May 9.
Electrochemical (EC) residual disinfection of Escherichia coli (E. coli) in the presence and absence of primary sludge particulates (PSPs) was studied. The kinetics followed a first-order rate law. When PSPs were absent, the EC residual disinfection rate coefficient (k) increased linearly with EC pretreatment energy (EC, 0-0.63 kWh/m(3)). However, with 143 mg PSPs/L, k first increased linearly with EC (0-0.28 kWh/m(3)) and then decreased linearly with EC (0.28-0.42 kWh/m(3)). H2O2 was detected during EC pretreatment in PSPs-free samples and the H2O2 concentration (CH) increased with EC (0-0.83 kWh/m(3)) linearly. Chloride was detected in PSPs aqueous samples (143 mg PSPs/L) and its concentration (CC) changed during EC pretreatment: initially, a decrease of CC was observed when EC increased from 0 to 0.28 kWh/m(3), followed by an increase of CC when EC increased 0.28-0.42 kWh/m(3). In both cases, k correlated to the initial post-EC chloride concentration (CCI) in an inverse linear relationship. This two-stage change of CC and k was caused by a combination of two reactions: anodic oxidation of chloride and the reaction of chloramines with excess chlorine. This paper explains the mechanisms underlying EC residual disinfection in the presence and absence of PSPs, and proposes a feasible strategy for EC disinfection when PSPs are present, an approach that could be useful in the treatment of combined sewage overflow (CSO).
电化学（EC）在存在和不存在原生污泥颗粒（PSPs）的情况下对大肠杆菌（E. coli）的残余消毒效果进行了研究。动力学遵循一级反应定律。当不存在 PSPs 时，EC 残余消毒速率系数（k）随 EC 预处理能量（EC，0-0.63 kWh/m³）呈线性增加。然而，当存在 143mg PSPs/L 时，k 最初随 EC 呈线性增加（0-0.28 kWh/m³），然后随 EC 呈线性减少（0.28-0.42 kWh/m³）。在无 PSPs 的 EC 预处理样品中检测到了 H2O2，并且 H2O2 浓度（CH）随 EC（0-0.83 kWh/m³）呈线性增加。在含有 143mg PSPs/L 的 PSPs 水溶液样品中检测到了氯化物，并且在 EC 预处理过程中其浓度（CC）发生了变化：当 EC 从 0 增加到 0.28 kWh/m³时，CC 首先减少，然后当 EC 增加到 0.28-0.42 kWh/m³时，CC 增加。在这两种情况下，k 与 EC 处理后的初始氯浓度（CCI）呈负线性相关。CC 和 k 的这种两阶段变化是由两种反应的结合引起的：氯化物的阳极氧化和氯胺与过量氯的反应。本文解释了在存在和不存在 PSPs 的情况下 EC 残余消毒的机制，并提出了在存在 PSPs 的情况下进行 EC 消毒的可行策略，这一方法在处理合流污水溢流（CSO）时可能有用。
