Dissolved organic carbon and trihalomethane precursor removal at a UK upland water treatment works.
Dissolved organic carbon and trihalomethane precursor removal at a UK upland water treatment works.
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DOI：
10.1016/j.scitotenv.2013.08.048
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发表时间：
2014-01
期刊：
影响因子：
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通讯作者：
R. Gough;P. Holliman;N. Willis;C. Freeman
中科院分区：
文献类型：
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作者：
R. Gough;P. Holliman;N. Willis;C. Freeman
在饮用水处理过程中去除溶解有机碳（DOC）对于维持水质美观标准、最大限度地减少微污染物浓度、控制分配系统内细菌再生长非常重要，而且至关重要的是，因为它含有一种可以充当三卤甲烷（THM）前体的子成分。本研究分析了进入某高地饮用水处理厂的原水DOC和THM生成潜力（THMFP）在12个月内的浓度和特性。原水DOC特性，标准化THMFP（STHMFP）和% DOC去除率之间的相关性也进行了研究。DOC和THM前体去除在一系列的治疗阶段进行了检查，在此期间，以及潜在的选择性去除DOC馏分，以评估不同的治疗阶段的DOC去除和THM改善的重要性。虽然THMFP去除率在整个研究期间保持较高且相当稳定（83-89%），但数据表明这主要是高DOC去除率的结果，而不是THM前体的选择性去除。虽然这种化学不可知论使DOC去除更强大，但它可能使整个过程更容易在不断变化的气候条件下超过允许的THM浓度。DOC和氯之间的反应的动力学出现季节性变化，表明时间的变化，快速和缓慢反应的前体的比例与THM浓度的影响，在交付给消费者的点。初始处理阶段，包括混凝-絮凝和溶解空气浮选（气浮）是迄今为止最重要的散装DOC去除和THM前体的优先去除方面，虽然，令人惊讶的是，DOC质量也修改后氯化和二级快速重力过滤（RGF）。虽然净三卤甲烷浓度下降后的初始处理阶段，溴化三卤甲烷（BrTHMs），据报道，这是更致癌的比例增加了一倍，也观察到。
The removal of dissolved organic carbon (DOC) during potable water treatment is important for maintaining aesthetic water quality standards, minimising concentrations of micro-pollutants, controlling bacterial regrowth within distribution systems and, crucially, because it contains a sub-component that can act as trihalomethane (THM) precursors. In this study, the concentration and characteristics of raw water DOC and THM formation potential (THMFP) entering an upland potable water treatment works were analysed over twelve months. Correlations between raw water DOC characteristics, standardised THMFP (STHMFP) and % DOC removal were also investigated. DOC and THM precursor removal during a series of treatment stages was examined over this period, as well as potential selectivity in the removal of DOC fractions, to assess the importance of different treatment stages for DOC removal and THM amelioration. Though THMFP removal remained high and fairly stable throughout the study period (83–89%), the data suggest that this was mostly the result of high DOC removal rates rather than the selective removal of THM precursors. Whilst this chemical agnosticism makes DOC removal more robust, it may make the overall process more vulnerable to exceeding permissible THM concentrations under changing climatic conditions. The kinetics of the reaction between DOC and chlorine appeared to vary seasonally, indicating temporal changes in the proportions of fast- and slow-reacting precursors with implications for THM concentrations at the point of delivery to the consumer. The initial treatment stages, comprising coagulation–flocculation and dissolved air floatation (DAF) were by far the most important in terms of bulk DOC removal and the preferential removal of THM precursors, though, surprisingly, DOC quality was also modified following chlorination and secondary rapid gravity filtration (RGF). Though net THM concentration decreased following initial treatment stages, a doubling in the proportion of brominated THMs (BrTHMs), which are reported to be more carcinogenic, was also observed.