Effect of organic matter on arsenic removal during coagulation/flocculation treatment
Effect of organic matter on arsenic removal during coagulation/flocculation treatment
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DOI：
10.1016/j.jcis.2009.09.068
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发表时间：
2010-02-01
影响因子：
9.9
通讯作者：
Bollinger, Jean-Claude
中科院分区：
文献类型：
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作者：
Pallier, Virginie;Feuillade-Cathalifaud, Genevieve;Bollinger, Jean-Claude
本研究的目的是评估有机物对混凝/絮凝去除砷的影响，模型水与低矿物质含量和天然水样。氯化铁被用作混凝剂的浓度，避免预氧化步骤通常需要氧化As（III），并增加其去除。砷的去除是通过结合砷残留浓度的评价和zeta电位测量的形态分析来完成的。初步研究评价了混凝剂投加量、混凝pH值和有机物对As（III）和As（V）去除的影响。主要结论如下：（i）As（III）的去除取决于混凝剂剂量和氢氧化物表面上可用的位点的数量，而不是混凝pH值;（ii）As（V）的去除取决于胶体悬浮液的zeta电位，并且比As（III）受混凝pH值和有机物的存在的影响更大;（iii）有机物的去除遵循As（V）的去除。这允许确定吸附作为主要机制发生在As（V）和有机物去除和假设沉淀/共沉淀作为一个重要的As（III）去除机制。吸附在预先形成的氢氧化铁絮体实验，然后确认这些假设。(C)2009 Elsevier Inc. All rights reserved.
The aim of this study is to evaluate the influence of organic matter on arsenic removal by coagulation/flocculation on both a model water with low mineral content and a natural water sample. Ferric chloride was used as coagulant at concentrations avoiding the preoxidation step usually required to oxidize As(III) and increase its removal. Arsenic removal was accomplished by combining evaluation of arsenic residual concentrations and speciation analysis with zeta potential measurements. A preliminary study evaluated the influence of coagulant dose, coagulation pH, and organic matter on As(III) and As(V) removal. The main conclusions were: (i) As(III) removal depended on coagulant dose and on the number of sites available on hydroxide surfaces rather than on coagulation pH; (ii) As(V) removal depended on the zeta potential of colloidal suspension and was more influenced than As(III) by coagulation pH and the presence of organic matter: (iii) organic matter removal followed As(V) removal. This allowed determination of adsorption as the main mechanism occurring during As(V) and organic matter removal and supposing precipitation/coprecipitation as an important As(III) removal mechanism. Adsorption on preformed ferric hydroxide flocs experiments allowed then confirmation of these hypotheses. (C) 2009 Elsevier Inc. All rights reserved.