Modeling and elucidation the effects of iron deposits on chlorine decay and trihalomethane formation in drinking water distribution system.
Modeling and elucidation the effects of iron deposits on chlorine decay and trihalomethane formation in drinking water distribution system.
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DOI：
10.1016/j.watres.2021.117804
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发表时间：
2021-10
期刊：
影响因子：
12.8
通讯作者：
Pei-lun Hua;Quan Gao;Zhenyu Wang;Shanshan Jiang;Keila Roberta Ferreira de Oliveira;Dhiogo Okumoto Macedo-Dhiogo-Okumoto
中科院分区：
文献类型：
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作者：
Pei-lun Hua;Quan Gao;Zhenyu Wang;Shanshan Jiang;Keila Roberta Ferreira de Oliveira;Dhiogo Okumoto Macedo-Dhiogo-Okumoto
铁沉积物通过不同的机制刺激饮用水分配系统中的氯消耗和三卤甲烷（THM）的形成。在这项研究中，二阶氯衰减模型与可变反应速率系数的定量评估铁沉积物对氯反应的影响，考虑溶解性有机物（DOM）的特性，类型和剂量的沉积物，以及初始氯浓度。在对余氯进行可靠预测的基础上，通过铁沉积物存在下DOM的氯化反应，进一步验证了THM生成量与氯消耗量呈线性关系的观点。由于催化作用的影响，DOM对氯衰变或THM形成的反应性被加速。虽然铁沉积物激活的DOM与溴和氯的反应性，THM略有转向氯化物种。由于吸附作用的影响，最大需氯量随存款剂量的增加而增加，而增加的程度主要取决于DOM的性质。低分子量DOM具有亲水性，易被铁沉积物升高。基于模型模拟，约20%的氯消耗和37%的THM的形成后，168 h的反应由沉积物贡献。本文提供的数据强调了铁沉积物在氯消耗和THM形成中的作用，这有助于饮用水分配系统的水质管理。
Iron deposits stimulate chlorine consumption and trihalomethane (THM) formation in drinking water distribution systems through distinct mechanisms. In this study, a second-order chlorine decay model with a variable reaction-rate coefficient was developed to quantitatively evaluate the influences of iron deposits on chlorine reactions by considering the characteristics of dissolved organic matter (DOM), the type and dosages of deposits, as well as the initial chlorine concentrations. Based on a reliable prediction of residual chlorine, the concept that THM formation had a linear relationship with chlorine consumption was further validated by chlorination of DOM in the presence of iron deposits. Due to the catalysis influences, the reactivity of DOM towards chlorine decay or THM formation was accelerated. Although iron deposits activated the reactivity of DOM with bromine and chlorine, THM slightly shifted toward chlorinated species. Due to the adsorption influences, the maximum chlorine demand increased with the increasing deposit dosages whereas the extent of enhancement mainly relied on the DOM properties. Low-molecular-weight DOM with a hydrophilic characteristic was prone to be elevated by iron deposits. Based on the model simulation, approximately 20% of chlorine consumption and 37% of THM formation were contributed by deposits after 168 h reaction. The data provided herein emphasize the role of iron deposits in chlorine consumption and THM formation, which assist the water quality management in drinking water distribution systems.