Role of aluminum speciation in the removal of disinfection byproduct precursors by a coagulation process.
Role of aluminum speciation in the removal of disinfection byproduct precursors by a coagulation process.
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DOI：
10.1021/es8006035
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发表时间：
2008-08
影响因子：
11.4
通讯作者：
He Zhao;Chengzhi Hu;Huijuan Liu;Xu Zhao;J. Qu
中科院分区：
文献类型：
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作者：
He Zhao;Chengzhi Hu;Huijuan Liu;Xu Zhao;J. Qu
提取腐殖酸（HA）并将其分离成不同分子量的组分，然后用氯化铝和聚合氯化铝（PAC 1）进行混凝。研究了混凝剂对消毒副产物（DBP）前体物的去除效果和铝形态的变化。特别是，铝形态的DBP前体的去除中的作用进行了讨论。在混凝过程中，AlCl3水解成占主导地位的原位Al13物种在pH 5.5。原位Al13物种表现出更好的去除能力卤代乙酸（HAA）的前体比PAC 1。在pH 7.5时，原位水解的AlCl3中的Al 13物种分解为二聚体Al物种。在这种情况下，PAC 1的预成型Al 13具有高的HAA前体去除能力。特别地，具有低MW（30 kDa）级分的HAA前体的最大减少是通过在pH 7.5下的吸附。与HAA前体不同，原位Al 13物种对三卤甲烷（THM）前体的去除能力不高。因此，在不同pH值下，PAC对THM前体物的去除能力均优于AlCl 3。在不同的MW级分中，THM前体的最大减少是通过在pH 5.5下的电荷中和。
Humic acid (HA) was extracted and separated into different molecular weight (MW) fractions, then coagulated by aluminum chloride and polyaluminum chloride (PACl). The removal of disinfection byproduct (DBP) precursors and the aluminum speciation variation of the coagulants were investigated in detail. In particular, the role of aluminum speciation in the removal of DBP precursors was discussed. During the coagulation process, AlCl3 hydrolyzed into dominating in situ Al13 species at pH 5.5. The in situ Al13 species exhibited better removal ability for haloacetic acid (HAA) precursors than PACl. At pH 7.5, in situ hydrolyzed Al13 species of AlCl3 decomposed into dimeric Al species. In this case, preformed Al13 of PACl had a high removal ability of HAA precursors. Specially, the greatest reduction of HAA precursors with a low MW ( 30 kDa) fractions was through adsorption at pH 7.5. Different from HAA precursors, the in situ Al13 species did not have a high removal ability of trihalomethane (THM) precursors. Therefore, PACl exhibited a better removal ability of THM precursors than AlCl3 at different pH values. In the different MW fractions, the greatest reduction of THM precursors was through charge neutralization at pH 5.5.