Zhou Xin, Zhang Jin-Zhong, Qiu Xin-Kai, Wang Ding-Yong
Key Laboratory of Eco-environments in Three Gorges Reservoir Region, Ministry of Education, College of Resources and Environment, Southwest University, Chongqing 400715, China.
Huan Jing Ke Xue. 2013 Nov;34(11):4304-10.
Kinetic characteristics of mercury ion (Hg2+) removal in wastewater by zero-valent iron (ZVI) and the influence factors were studied, and the reaction mechanism of ZVI and Hg2+ was preliminarily discussed. The removal rate of Hg2+ in wastewater reached 94.5% under the optimal removal conditions, i. e. the initial concentration of Hg2+ was 0.10 mg x L(-1), the initial pH was 5, the ZVI dosage was 0.050 g, and the temperature was 25 degrees C. There was a rapid removal process for Hg2+ in wastewater by ZVI, which could be described by the pseudo first-order reaction kinetic equation, and the rate constant was 0.010 min(-1). The removal mechanism of Hg2+ may mainly be attributed to the oxidation-reduction of ZVI, and the adsorption and flocculation precipitation of iron oxides and hydroxides. However, the passivation of FeOOH and Fe2O3-Fe3O4 on ZVI surface may be the main reason for the decrease in the removal rate of Hg2+. Humic acid (HA) in wastewater could not only form Fe-HA complex with the Fe2+ and Fe3+ produced by ZVI reduction, which increased the ratio of soluble iron and relieved ZVI passivation, but also stabilize fine iron oxide and iron hydroxide colloid, and thus enhance the adsorption of Hg2+ in wastewater.
研究了零价铁（ZVI）去除废水中汞离子（Hg2+）的动力学特性及影响因素，并初步探讨了ZVI与Hg2+的反应机理。在最佳去除条件下，即Hg2+初始浓度为0.10 mg·L(-1)、初始pH为5、ZVI投加量为0.050 g、温度为25℃时，废水中Hg2+的去除率达到94.5%。ZVI对废水中Hg2+有快速去除过程，可用准一级反应动力学方程描述，速率常数为0.010 min(-1)。Hg2+的去除机理可能主要归因于ZVI的氧化还原作用以及铁氧化物和氢氧化物的吸附与絮凝沉淀。然而，ZVI表面FeOOH和Fe2O3-Fe3O4的钝化可能是Hg2+去除率下降的主要原因。废水中的腐殖酸（HA）不仅能与ZVI还原产生的Fe2+和Fe3+形成Fe-HA络合物，提高可溶性铁的比例并缓解ZVI钝化，还能稳定细小的铁氧化物和氢氧化铁胶体，从而增强对废水中Hg2+的吸附。
Zotero 插件