Competitive removal of water-borne copper, zinc and cadmium by a CaCO3-dominated red mud
Competitive removal of water-borne copper, zinc and cadmium by a CaCO3-dominated red mud
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以 CaCO3 为主的赤泥竞争性去除水中的铜、锌和镉。
DOI：
10.1016/j.jhazmat.2009.07.135
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发表时间：
2009-12-30
影响因子：
13.6
通讯作者：
Liu, Yong
中科院分区：
文献类型：
--
作者：
Ma, Yingqun;Lin, Chuxia;Liu, Yong
采用间歇实验研究了以CaCO3为主的赤泥对水中Cu、Zn和Cd的竞争去除。结果表明，水性铜与赤泥的亲和力较高。与水体中的Zn和Cd相比，红泥优先吸附铜的主要机理是氯铜矿的形成。最初，氯铜矿可能主要通过CuCl 2和NaOH之间的反应形成。随着NaOH用量的增加，CuCl 2与CaCO 3反应生成氯铜矿的作用越来越重要。连续萃取结果表明，在实验的早期阶段，水载金属优先与NH2OH中心点HCl可萃取级分。随着赤泥颗粒上金属结合位饱和度的增加，HCH3COO可萃取态Cu的比例相应增加。水载锌和镉也越来越多地结合在HCH3COO可提取的形式，直到金属的结合能力的赤泥几乎耗尽。当赤泥颗粒的结合位点饱和后，部分吸附在赤泥中的Zn和Cd被水溶性Cu置换，从而使吸附在赤泥中的Zn和Cd释放到溶液中。(C)2009爱思唯尔有限公司版权所有。
Batch experiments were conducted to investigate the competitive removal of water-borne Cu, Zn and Cd by a CaCO3-dominated red mud. The results show that the water-borne Cu had a higher affinity to the red mud. as compared to the water-borne Zn and Cd. The major mechanism responsible for the preferential retention of Cu by red mud was the formation of atacamite. It is likely that, initially, atacamite was formed mainly through the reaction between CuCl2 and NaOH. Reaction between CuCl2 and CaCO3 to form atacamite became more and more important with the gradual consumption of NaOH. Sequential extraction results show that the water-borne metals were preferentially associated with the NH2OH center dot HCl-extractable fractions at the early stage of the experiment. With increase in the saturation degree of binding sites on red mud particles by the metals, the proportion of HCH3COO-extractable Cu fraction increased accordingly. Water-borne Zn and Cd were also increasingly bound in the HCH3COO-extractable forms until the metal binding capacity of the red mud was nearly depleted. After the binding sites of red mud particles were saturated, part of the Zn and Cd previously retained by the red mud was displaced by water-borne Cu, resulting in the release of the previously immobilized Zn and Cd to the solution. (C) 2009 Elsevier B.V. All rights reserved.