水中Ni^(2+)在粒状沸石/活性炭复合材料上的吸附研究

Adsorption of Ni^(2+) from aqueous solution on granular zeolite NaA/activated carbon composite

采用廉价的煤矸石为主要原料,添加一定量的沥青粉制备了沸石NaA/活性炭粒状复合材料,并以此作为吸附剂,研究了水溶液中Ni2+在该复合材料中的吸附行为,考察溶液的初始浓度、吸附时间和pH对吸附的影响。结果表明溶液较高的pH值有利于Ni2+在吸附剂上的吸附;随Ni2+初始浓度的增大复合材料的吸附量增大,而Ni2+的去除率随之减小;Ni2+在复合材料上的吸附接近Langmuir-Freundlich等温吸附模型,反映了吸附表面的多相性及两类吸附中心在复合材料上的共存性;吸附速率遵循准二级吸附动力学模型。

Granular zeolite NaA/activated carbon composite has been prepared by adding pitch powder into elutrilithe as raw material.The capability of the composite to remove Ni2+ ions from aqueous solutions by adsorption has been investigated under conditions of various pH,initial concentrations of metal ions and contact time.The capacity of adsorption increases with the increase of pH and initial concentration,and the removal of Ni2+ ions can be 97.8% with the initial concentration of 23.4 mg/L and pH of 4.3.The adsorption isotherm fits well with the Langmuir-Freundlich isotherm (n=1.757),indicating the surface heterogeneity of the adsorbent and coexistence of two kinds of adsorption sites in composite.The overall rate of adsorption is pseudo-second order for the uptake of Ni2+.