Comparison of Trihalomethane Formation Using Chlorine-Based Disinfectants Within a Model System; Applications Within Point-of-Use Drinking Water Treatment
Comparison of Trihalomethane Formation Using Chlorine-Based Disinfectants Within a Model System; Applications Within Point-of-Use Drinking Water Treatment
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DOI：
10.3389/fenvs.2019.00035
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发表时间：
2019-03-22
影响因子：
4.6
通讯作者：
Reynolds, Darren M.
中科院分区：
文献类型：
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作者：
Clayton, Gillian E.;Thorn, Robin M. S.;Reynolds, Darren M.
使用点(POU)饮用水处理系统为没有集中设施的社区提供解决方案。有效的POU系统治疗和减少POU供水中的病原体数量，通常使用消毒。随着时间的推移，氯消毒会通过氯与天然有机物(NOM)的反应形成消毒副产物(DBP)，如三卤代甲烷(THMS)。尽管已知三氯甲烷对人类健康有害，但人们对其在POU系统内的生产知之甚少。这项研究比较了电化学激活溶液(ECAS)、次氯酸(HOCl)和次氯酸钠(NaOCl)这三种消毒剂在POU饮用水系统中产生三氯甲烷的潜力。采用顶空气相固相微萃取(HS-SPME)气相色谱-质谱法(GC-MS)测定了经处理的含NOM(苏万尼河腐植酸，4 mg L-1)水样中的THMS。所有消毒处理都与游离氯浓度1、3和5 mg L-1相匹配，反应时间分别为1、5和10min。所有消毒剂在游离氯浓度为5 mg L-1、反应时间为5分钟和10分钟时均可产生三甲氧基甲烷。与NaOCl相比，ECAs或HOCl导致在所有反应时间内形成的总THM浓度和游离氯浓度显著降低。在POU生产时，只需要水、盐和能源就可以产生ECA，这项研究表明，与NaOCl相比，使用ECA可以减少THMS的生成。需要进一步的工作来在扩大的POU水处理系统中复制这些发现。
Point-of-use (POU) drinking water treatment systems provide solutions for communities where centralized facilities are unavailable. Effective POU systems treat and reduce the number of pathogens in POU water supplies often employing disinfection. Chlorine disinfection results in the formation of disinfection by-products (DBPs), such as trihalomethanes (THMs), through the reaction of chlorine with natural organic matter (NOM) over time. Although THMs are known to be harmful to human health, little is known about their production within POU systems. This study compares the disinfectants; Electrochemically Activated Solutions (ECAS), hypochlorous acid (HOCl), and sodium hypochlorite (NaOCl), with respect to their potential to produce THMs within POU drinking water systems. Headspace solid-phase microextraction (HS-SPME) gas chromatography mass spectrometry (GC-MS) was utilized to quantify THMs in treated water samples containing NOM (Suwannee River humic acid, 4mg L-1). All disinfection treatments were matched to free chlorine concentrations of 1, 3, and 5mg L-1, using reaction times of 1, 5, and 10min. THMs were produced at free chlorine concentrations of 5mg L-1 and at reaction times of 5 and 10min for all disinfectants. ECAS or HOCl, resulted in the formation of significantly lower total THM concentrations across all reaction times and free chlorine concentrations, compared to NaOCl. ECAS can be generated at the POU requiring only water, salt and energy for production, and this study demonstrates that its use results in reduced formation of THMs, compared with NaOCl. Further work is required to replicate these findings within scaled-up POU water treatment systems.