State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, Jiangsu 210023, China.
Water Res. 2024 Aug 15;260:121932. doi: 10.1016/j.watres.2024.121932. Epub 2024 Jun 12.
Disinfection efficiency and disinfection byproduct (DBP) formation are two important aspects deserving careful consideration when evaluating different disinfection protocols. However, most of the previous studies on the selection of disinfection methods by comparing DBP formation were carried out under the same initial/residual dose and contact time of different disinfectants, and such a practice may cause overdose or underdose of a certain disinfectant, leading to the inaccurate evaluation of disinfection. In this study, a comprehensive and quantitative comparison of chlorine (Cl) and chlorine dioxide (ClO) disinfection was conducted with regard to their DBP formation under equal disinfection efficiency. The microbial inactivation models as well as the Cl and ClO demand models were developed. On such basis, the integral CT (ICT) values were determined and used as a bridge to connect disinfection efficiency and DBP formation. For 3-log and 4-log reductions of Pseudomonas aeruginosa, ClO had 1.5 and 5.8 times higher inactivation ability than Cl, respectively. In the premise of equal disinfection efficiency (i.e., the ICT ratios of Cl to ClO = 1.5 and 5.8), the levels of total organic chlorine, total organic bromine, and total organic halogen formed in the Cl disinfection were significantly higher than those formed in the ClO disinfection. Among the 35 target aliphatic DBPs, trihalomethanes (THMs) and haloacetic acids (HAAs) were the dominant species formed in both Cl and ClO disinfection. The total THM levels formed in Cl disinfection were 14.6 and 30.3 times higher than those in ClO disinfection, respectively. The total HAA levels formed in Cl disinfection were 3.5 and 5.4 times higher than those in ClO disinfection, respectively. Formation of the target 48 aromatic DBPs was much favored in Cl disinfection than that in ClO disinfection, and the formation levels was dominated by contact time. This study demonstrated that ClO had significant advantages over Cl, especially at higher microorganism inactivation and lower DBP formation requirements.
消毒效率和消毒副产物 (DBP) 形成是评估不同消毒方案时需要仔细考虑的两个重要方面。然而，以前大多数关于通过比较 DBP 形成选择消毒方法的研究都是在相同的初始/残留剂量和不同消毒剂的接触时间下进行的，这种做法可能会导致某种消毒剂的剂量过高或过低，从而导致消毒效果评估不准确。在这项研究中，以相同的消毒效率为基础，对氯 (Cl) 和二氧化氯 (ClO) 消毒进行了全面和定量的比较，比较了它们的 DBP 形成情况。建立了微生物灭活模型以及 Cl 和 ClO 需求模型。在此基础上，确定了积分 CT (ICT) 值，并将其用作连接消毒效率和 DBP 形成的桥梁。对于铜绿假单胞菌的 3 对数和 4 对数减少，ClO 的灭活能力分别比 Cl 高 1.5 倍和 5.8 倍。在相同的消毒效率前提下（即 ICT 比值 Cl/ClO=1.5 和 5.8），Cl 消毒形成的总有机氯、总有机溴和总有机卤的水平明显高于 ClO 消毒形成的水平。在 35 种目标脂肪族 DBP 中，三卤甲烷 (THMs) 和卤乙酸 (HAAs) 是 Cl 和 ClO 消毒中形成的主要物质。Cl 消毒形成的总 THM 水平分别比 ClO 消毒高出 14.6 倍和 30.3 倍。Cl 消毒形成的总 HAA 水平分别比 ClO 消毒高出 3.5 倍和 5.4 倍。在 Cl 消毒中，目标 48 种芳香族 DBP 的形成明显优于 ClO 消毒，形成水平主要受接触时间的控制。这项研究表明，ClO 比 Cl 具有显著优势，特别是在更高的微生物灭活和更低的 DBP 形成要求下。
