Natural materials for treatment of industrial effluents:: comparative study of the retention of Cd, Zn and Co by calcite and hydroxyapatite.: Part 1:: batch experiments
Natural materials for treatment of industrial effluents:: comparative study of the retention of Cd, Zn and Co by calcite and hydroxyapatite.: Part 1:: batch experiments
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DOI：
10.1016/j.jenvman.2004.02.004
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发表时间：
2004-06-01
影响因子：
8.7
通讯作者：
Cicerone, DS
中科院分区：
文献类型：
--
作者：
del Río, JAG;Morando, PJ;Cicerone, DS
这项工作探讨了从自然界丰富的矿物中开发的材料的重金属保留能力，成本低，对环境的影响最小。为了实现这一目标，我们已经：（a）表征方解石（CA）和羟基磷灰石（HAP）的商业样品-包括它们的表面性质（BET面积、电泳迁移率、SEM和X射线能量色散光谱）;和（B）通过分批实验定性和定量Cd、Zn和Co与方解石（CaCO 3）和羟基磷灰石[Ca-5（PO 4）（3）OH]的相互作用，结果表明，重金属在CA和HAP表面的亲合力分别为Cd > Zn > Co和Cd > Zn，与Co相近。保留率随pCa和pH的增加而增加，并且可以通过以下机制来模拟：（a）对于Cd，Zn和Co到CA上的吸附的非理想离子交换机制（Me/Ca）;和（B）对于HAP的情况，非理想离子交换和特异性吸附机制（Me/Ca和= PO 4 O-Me）。CA对pH的依赖性是间接的，与其溶解度的变化有关（pCa随pH增加而增加，对Cd、Zn和Co的吸附也随pH增加而增加）。前者具有更好的水处理性能，因为其对Cd，Zn和Co的保留效率更高（每克材料超过两个数量级），并且在较宽的pH范围内（6 < pH < 9）具有较低的溶解度。(C)2004爱思唯尔有限公司版权所有
This work explores the heavy metal retention capacity of materials developed from minerals that are abundant in nature, with low cost and minimum environmental impact. To accomplish this objective we have: (a) characterized commercial samples of calcite (CA) and hydroxyapatite (HAP)-including their surface properties (BET area, electrophoretic mobility, SEM, and X-ray energy dispersive spectroscopy); and, (b) qualified and quantified the interaction of Cd, Zn and Co with calcite (CaCO3) and hydroxyapatite [Ca-5(PO4)(3)OH] through batch experiments, in a range of metal concentrations (4 < pMe < 8) and pH (6 < pH < 8.6).Results show that the affinities of the studied heavy metals for CA and HAP surfaces follow the sequence: Cd > Zn > Co and Cd > Zn approximate to Co, respectively. Retention increased with pCa and pH and could be modeled by: (a) a non-ideal ion exchange mechanism (Me/Ca) for the adsorption of Cd, Zn and Co onto CA; and, (b) a mechanism of non-ideal ion exchange and specific adsorption (Me/Ca and = PO4O-Me) in the case of HAP. The pH dependence is indirect in CA and is related to its solubility changes (pCa increases with pH, and so does sorption of Cd, Zn and Co).Both materials, HAP and CA, can be used for heavy metal retention. The former has better performance for water treatment due to its greater efficiency for the retention of Cd, Zn and Co (over two orders of magnitude per gram of material) and its lower solubility in a wide range of pH (6 < pH < 9). (C) 2004 Elsevier Ltd. All rights reserved