Arsenate and arsenite removal by zerovalent iron: Effects of phosphate, silicate, carbonate, borate, sulfate, chromate, molybdate, and nitrate, relative to chloride
Arsenate and arsenite removal by zerovalent iron: Effects of phosphate, silicate, carbonate, borate, sulfate, chromate, molybdate, and nitrate, relative to chloride
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DOI：
10.1021/es010768z
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发表时间：
2001-11-15
影响因子：
11.4
通讯作者：
Puls, RW
中科院分区：
文献类型：
--
作者：
Su, CM;Puls, RW
通过间歇试验研究了无机阴离子竞争对零价铁去除水中砷（As（V））和砷（As（III））动力学的影响。含氧阴离子在As（V）或As（III）的存在下与Peerless Fe-0发生了以吸附为主的反应（磷酸盐、硅酸盐、碳酸盐、硼酸盐和硫酸盐）或以还原为主的反应（铬酸盐、铬酸盐和硝酸盐）。伪一阶速率方程被发现满意地描述两个As（V）和As（III）的去除动力学在每个竞争阴离子的存在下。在pH值为7至9的范围内对Peerless Fe-0进行测试的含氧阴离子中，磷酸盐导致As去除率（7.0 x 10（-3）至18.5 x 10（-3）h（-1））相对于氯化物（34.9 x 10（-3）至36.2 x 10（-3）h（-1））的最大下降。硅酸盐、铬酸盐、硫酸盐对As（III）的去除也有较强的抑制作用，其次是碳酸盐和硝酸盐，而硼酸盐和硫酸盐对As（III）的去除只有轻微的抑制作用。目前的研究结果表明，Peerless Fe-0可能是一个很好的渗透反应屏障介质的一组混合无机污染物。在设计由零价铁组成的可渗透反应屏障修复As（V）和As（III）时，应考虑阴离子竞争效应。
Batch tests were performed to evaluate the effects of inorganic anion competition on the kinetics of arsenate (As(V)) and arsenite (As(III)) removal by zerovalent iron (Peerless Fe-0) in aqueous solution. The oxyanions underwent either sorption-dominated reactions (phosphate, silicate, carbonate, borate, and sulfate) or reduction-dominated reactions (chromate, molybdate, and nitrate) with Peerless Fe-0 in the presence of As(V) or As(III), relative to chloride. Pseudo-first-order rate equations were found to describe satisfactorily both As(V) and As(III) removal kinetics in the presence of each competing anion. Of the oxyanions tested for Peerless Fe-0 in the pH range from 7 to 9, phosphate caused the greatest decrease in As removal rate (7.0 x 10(-3) to 18.5 x 10(-3) h(-1)) relative to chloride (34.9 x 10(-3) to 36.2 x 10(-3) h(-1)). Silicate, chromate, and molybdate also caused strong inhibition of As removal, followed by carbonate and nitrate, whereas borate and sulfate only caused slight inhibition to As(III) removal. Present results show that Peerless Fe-0 may be an excellent permeable reactive barrier medium for a suite of mixed inorganic contaminants. The anion competing effects should be considered when designing permeable reactive barriers composed of zerovalent iron for field applications to remediate As(V) and As(III).