Chen Hao, Wang Aiqin
Center of Eco-Material and Green Chemistry, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou 730000, People's Republic of China.
J Colloid Interface Sci. 2007 Mar 15;307(2):309-16. doi: 10.1016/j.jcis.2006.10.054. Epub 2006 Dec 29.
The use of a natural palygorskite clay for the removal of Pb(II) from aqueous solutions for different contact times, pHs of suspension, and amounts and particle sizes of palygorskite clay were investigated. The variations of the pH value of Pb(II) solutions on natural palygorskite in the adsorption process were determined. Batch adsorption kinetic experiments revealed that the adsorption of Pb(II) onto palygorskite clay involved fast and slow processes. It was found that the adsorption mechanisms in the lead/palygorskite system follow pseudo-second-order kinetics with a significant contribution from film diffusion. SEM observations demonstrated that an important interaction at the lead-granule interface occurred during the adsorption process. The adsorption isotherms were described by means of the Langmuir and Freundlich isotherms and the Langmuir model represents the adsorption process better than the Freundlich model. The maximum adsorption capacity of Pb(II) onto natural palygorskite was 104.28 mg g(-1).
研究了使用天然坡缕缟石粘土从水溶液中去除Pb(II)，考察了不同接触时间、悬浮液pH值、坡缕缟石粘土用量和粒径对去除效果的影响。测定了吸附过程中Pb(II)溶液在天然坡缕缟石上pH值的变化。间歇吸附动力学实验表明，Pb(II)在坡缕缟石粘土上的吸附涉及快速和慢速过程。研究发现，铅/坡缕缟石体系中的吸附机制遵循准二级动力学，膜扩散起了重要作用。扫描电子显微镜观察表明，吸附过程中铅颗粒界面发生了重要的相互作用。采用Langmuir和Freundlich等温线描述吸附等温线，Langmuir模型比Freundlich模型更能体现吸附过程。天然坡缕缟石对Pb(II)的最大吸附容量为104.28 mg g(-1)。
