As(III) oxidation by active chlorine and subsequent removal of As(V) by Al13 polymer coagulation using a novel dual function reagent.
As(III) oxidation by active chlorine and subsequent removal of As(V) by Al13 polymer coagulation using a novel dual function reagent.
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DOI：
10.1021/es203917g
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发表时间：
2012-05
影响因子：
11.4
通讯作者：
Chengzhi Hu;Huijuan Liu;Guixia Chen;William A. Jefferson;J. Qu
中科院分区：
文献类型：
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作者：
Chengzhi Hu;Huijuan Liu;Guixia Chen;William A. Jefferson;J. Qu
电化学制备的水处理剂含有高浓度的Al（13）聚合物和活性氯（PACC），由于氧化和混凝的组合作用，显示出良好的去除As（III）的潜力。结果表明，PACC通过活性氯的氧化和Al（13）聚合物的混凝去除As（V），对As（III）有较好的去除效果。在PACC中，As（III）被活性氯氧化为As（V），化学计量比为0.99mgCl（2）/mgAs（III）。Al（13）聚合物是PACC中除As（V）最活跃的Al物种。为满足饮用水砷标准，PACC中Cl（2）/Al的化学计量比为0.09，用于处理As（III）。综合考虑As（III）的氧化和As（V）的混凝过程，PACC去除As的最佳pH值在中性范围内，有利于As（III）与活性氯的反应，有利于Al（V）絮体的形成。腐殖酸的存在下，降低了As（III）的去除效率的PACC由于其对随后的As（V）混凝的负面影响，和消毒副产物的产量是非常低的存在下，不足或化学计量的活性氯。
An electrochemically prepared water treatment reagent containing a high concentration of Al(13) polymer and active chlorine (PACC) showed promising potential for the removal of As(III) due to the combined function of oxidation and coagulation. The results indicated that PACC was effective for As(III) removal through oxidation by the active chlorine and subsequent removal of As(V) by coagulation with the Al(13) polymer. The As(III) was oxidized to As(V) by active chlorine in PACC, with a stoichiometric rate of 0.99 mg Cl(2)/mg As(III). The Al(13) polymer was the most active Al species responsible for As(V) removal in PACC. To meet As drinking water standards the stoichiometric weight ratio of Cl(2)/Al within PACC was 0.09 for the treatment of As(III). Considering the process of As(III) oxidation and As(V) coagulation together, the optimal pH conditions for the removal of As by PACC was within the neutral range, which facilitated the reaction of As(III) with active chlorine and favored the formation of Al hydroxide flocs. The presence of humic acid reduced the As(III) removal efficiency of PACC due to its negative influence on subsequent As(V) coagulation, and disinfection byproduct yields were very low in the presence of insufficient or stoichiometric active chlorine.