改性膨润土对水中苯甲酸的吸附

摘要

采用氯化钠对膨润土进行钠化,与聚二甲基二烯丙基氯化铵(PDMDAAC)作用制得PDMDAAC-膨润土.经FTIR 分析,研究PDMDAAC-膨润土对水中苯甲酸的最佳吸附条件、吸附动力学及等温线拟合.结果表明:当选取吸附剂用量为0.5g,吸附时间为1h,吸附酸度为pH =4时,PDMDAAC-膨润土可吸附0.5 mmol／L的苯甲酸,其最大吸附效率可达86.57％.PDMDAAC -膨润土对苯甲酸的吸附符合拟二级动力学方程及Langmuir型等温曲线.%Using sodium modified bentonite and polydimethydiallylammonium chloride, we prepared polydimethydiallylammonium chloride-bentonite ( PDMDAAC-bentonite) via exchange reaction and analyzed it by FTTR. The adsorption behavior of benzoic acid by PDMDAAC-bentonite was studied,and the best experimental conditions were investigated. Experimental results show that PDMDAAC-bentonite can adsorb 0.5 mmol/L benzoic acid with the maximal removal efficiency of 86. 57% under the optimial conditons of 0. 5 g sorbent,1 h adsorption time and pH =4. The adsorption kinetic data of benzoic acid by PDMDAAC-bentonite fitts the pseudo-second-order model well, and its adsorption isotherm meets with Langmuir adsorption model.