镍改性硅藻土对废水中Pb(Ⅱ)吸附性能的研究
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摘要
采用SEM,XRD对改性硅藻土进行表征,考察了改性剂加入量、吸附剂的投入量、溶液初始浓度、溶液初始pH值和吸附时间等因素对铅离子在改性硅藻土上吸附的影响,并进行了吸附动力学研究.结果表明:改性后孔径明显比原生硅藻土大,同时,SiO_2的结晶度明显增强,这说明经高温煅烧去除了一部分有机杂质;改性硅藻土对铅离子吸附量可达到62. 67 mg/g;改性硅藻土对铅离子的吸附行为符合准二级动力学模型.
Modified diatomite adsorbent used for the removal of Pb(Ⅱ) from waste water was prepared by fully mixing diatomite samples with Ni~(2+) solution and CTAB. The adsorbent was characterized by Scanning Electron Microscope( SEM) and X-Ray diffractome( XRD). Batch adsorption experiments were conducted to study the influence of various factors,such as the amount of Ni~(2+),adsorbent dose,initial concentration of Pb(Ⅱ) solution,initial p H,and contact time on the adsorption of Pb(Ⅱ) solution. At the same time,the adsorption kinetics was investigated. The results indicate that the morphology of diatomite changed greatly after the modification,and the pore size of the modified diatomite was obviously larger than the original native diatomite. After the modification,the crystallinity of SiO_2 was obviously enhanced,indicating that some organic impurities were removed by high temperature calcination. The adsorption amount of Pb(Ⅱ) on the modified diatomite could reach 62. 67 mg/g. The adsorption behavior of the modified diatomite in Pb(Ⅱ) solution is well fitted to the pseudo-second-order kinetic model.
Modified diatomite adsorbent used for the removal of Pb(Ⅱ) from waste water was prepared by fully mixing diatomite samples with Ni~(2+) solution and CTAB. The adsorbent was characterized by Scanning Electron Microscope( SEM) and X-Ray diffractome( XRD). Batch adsorption experiments were conducted to study the influence of various factors,such as the amount of Ni~(2+),adsorbent dose,initial concentration of Pb(Ⅱ) solution,initial p H,and contact time on the adsorption of Pb(Ⅱ) solution. At the same time,the adsorption kinetics was investigated. The results indicate that the morphology of diatomite changed greatly after the modification,and the pore size of the modified diatomite was obviously larger than the original native diatomite. After the modification,the crystallinity of SiO_2 was obviously enhanced,indicating that some organic impurities were removed by high temperature calcination. The adsorption amount of Pb(Ⅱ) on the modified diatomite could reach 62. 67 mg/g. The adsorption behavior of the modified diatomite in Pb(Ⅱ) solution is well fitted to the pseudo-second-order kinetic model.
引文
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[7]朱健,王平,雷明婧,等.硅藻土的复合改性及其对水溶液中Cd2+的吸附特性[J].环境科学学报,2016,36(6):2060-2065.
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[4]刘志江,彭浩,朱卫国.改性硅藻土对铅吸附性能的研究[J].当代化工,2015,44(7):1484-1486.
[5] SHI Z,YUAN M,YANG X,et al. Adsorptive removal of Pb2+ using magnetic chitosan modified diatomite[J].Chinese Journal of Environmental Engineering,2017,11(2):787-792.
[6]张晓蕾,陈静,韩京龙,等.壳-核结构Fe3O4/MnO2磁性吸附剂的制备、表征及铅吸附去除研究[J].环境科学学报,2013,33(10):2730-2736.
[7]朱健,王平,雷明婧,等.硅藻土的复合改性及其对水溶液中Cd2+的吸附特性[J].环境科学学报,2016,36(6):2060-2065.