Removal of lead ions in aqueous solution by hydroxyapatite/polyurethane composite foams
Removal of lead ions in aqueous solution by hydroxyapatite/polyurethane composite foams
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DOI：
10.1016/j.jhazmat.2007.08.003
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发表时间：
2008-04-15
影响因子：
13.6
通讯作者：
Lee, Sang Cheol
中科院分区：
文献类型：
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作者：
Jang, Suk Hyun;Min, Byung Gil;Lee, Sang Cheol
制备了HAP含量分别为20%和50%的HAP/PU复合泡沫塑料，考察了不同初始Pb2+浓度和pH值2~6条件下HAP/PU复合泡沫塑料对水中Pb2+离子的去除能力。合成的HAP/PU复合泡沫塑料具有良好的开孔结构，为水溶液和Pb2+离子的吸附提供了通道。随着复合泡沫塑料中HAP含量的增加，复合泡沫塑料对Pb2+离子的吸附能力增强，但由于HAP在复合泡沫塑料中的分散性较差，去除速度较慢。随着水溶液中Pb2+离子初始浓度的增加，Pb2+离子的去除速率也变慢。复合材料对Pb2+的去除机理因水溶液的pH值不同而不同：在较低的pH 2~3范围内，以HAP的溶解和水溶液中Pb2+的析出为主，在较高的pH 5~6范围内，Pb2+在HAP/PU复合材料表面的吸附和Pb2+与水溶液中Pb2+的离子交换反应占主导地位，在pH值为4的条件下，两种去除机理相互竞争。HAP/PU复合泡沫对Pb2+的平衡去除过程符合Langmuir等温线模型，当HAP含量为50wt%时，复合泡沫的最大吸附容量为150 mg/g。(C)2007 Elsevier B.V.保留所有权利。
We have prepared hydroxyapatite/polyurehthane (HAp/PU) composite foams with two different HAp contents of 20 and 50 wt.% and investigated their removal capability of Pb2+ ions from aqueous solutions with various initial Pb2+ ion concentrations and pH values of 2-6. HAp/PU composite foams synthesized exhibited well-developed open pore structures which provide paths for the aqueous solution and adsorption sites for Pb2+ ions. With increasing the HAp content in the composites, the removal capability of Pb2+ ions by the composite foams increases owing to the higher adsorption capacity, whereas the removal rate is slower due to the less uniform dispersity of HAp in composite foams. The removal rate of Pb2+ ions is also slower with increasing the initial Pb2+ ion concentration in aqueous solutions. The removal mechanism of Pb2+ ion by the composites is varied, depending on the pH value of aqueous solution: the dissolution of HAp and precipitation of hydroypyromorphite is dominant at lower pH 2-3, the adsorption of Pb2+ ions on the HAp/PU composite surface and ion exchange reaction between Ca2+ of HAp and Pb2+ in aqueous solution is dominant at higher pH 5-6, and two removal mechanisms compete at pH 4. The equilibrium removal process of Pb2+ ions by the HAp/PU composite foam at pH 5 was described well with the Langmuir isotherm model, resulting in the maximum adsorption capacity of 150 mg/g for the composite foam with 50 wt.% HAp content. (c) 2007 Elsevier B.V. All rights reserved.