草酸改性杨树叶对六价铬的吸附性能

利用草酸改性杨树叶为试验材料,对溶液中六价铬进行吸附去除。试验结果表明:当p H=2,吸附剂剂量为0.3 g,反应时间为120 min时,该材料对50 m L浓度为50 mg/L含铬废水的去除率达99.1%;伪二级动力学方程能较好地拟合该材料对Cr(VI)的吸附动力学过程,揭示其吸附主要是离子交换吸附;Langmuir方程能较好模拟该材料对Cr(VI)的等温吸附过程,表明其吸附主要是单分子层吸附,最大吸附量为40.91 mg/g。热力学研究表明,Cr(VI)在该材料表面的吸附是一个自发、吸热的物理吸附过程。

ADSORPTION CHARACTERISTICS OF HEXAVALENT CHROMIUM ON POPLAR LEAF MODIFIED BY OXALATE

Poplar leaf modified by oxalate as a novel biosorbent was investigated to remove Cr( VI) from aquatic solution in batch experiment． The results indicated that when the pH was 2. 0，adsorbate dosage was 0. 3 g，reaction time was 120 min， the remove rate of the concentration of 50 mg /L Cr( VI) wastewater was 99. 1%． The kinetic adsorption process of Cr( VI) ions on poplar leaf modified by oxalate was fitted by pseudo-second-order kinetic model，and the adsorption was mainly ion exchange adsorption． Langmuir equation could simulate the material process of isothermal adsorption of Cr ( VI) ． The fitting results indicated the adsorption of Cr ( VI ) ions was monolayer adsorption，and the maximum adsorption capacity was 40. 91 mg /g． The thermodynamics analysis showed that the adsorption process of Cr( VI) ions on poplar leaf modified by oxalate was spontaneous，endothermic physical adsorption．