改性斜发沸石吸附除水中铬(Ⅵ)的研究

A STUDY ON REMOVAL OF CHROMIUM(Ⅵ)FROM WATER BY ADSORPTION ONTO MODIFIED CLINOPTILOLITE

摘要: 采用静态吸附法研究了镁铝碱式盐改性斜发沸石的吸附除铬(Ⅵ)性能,研究了pH值、接触时间、吸附剂量、初始浓度等对吸附的影响。结果表明,改性斜发沸石吸附铬(Ⅵ)的速度很快,30min内可以接近达到最大吸附量。研究了吸附与溶液pH的关系,得到了优化pH值并解释了吸附机理。吸附的最佳pH值约为4～6。用Langmuir方程拟合了吸附等温线,计算的饱和吸附量为4.5²mg/g。用拟二级动力学方程描述了吸附速率并计算了速率参数。

Abstract: Clinoptilolite modified by hydrotalcite was studied by static adsorption method to assess its capacity for the adsorption of chromium(Ⅵ)from synthetic solutions.Influence of pH,contact time,adsorbent dose and initial concentration on the adsorption was investigated.The modified clinoptilolite was found to adsorb chromium(Ⅵ)rapidly.The maximum amount of adsorption nearly reached in 30 minutes.The dependence of the adsorption on the pH was studied to achieve the optimum pH-value and the adsorption mechanism was explained.The maximum adsorption took place at pH-value of 4～6.Langmuir equations could describe the adsorption isotherms data,the amount of saturate adsorption calculated was 4.5²mg/g.Pseudo-second-order kinetics equation was used to describe the adsorption rate and adsorption rate constant was calculated.