环境工程学报2012，Vol.6Issue(12)：4504-4512,9.
核桃壳粉对水溶液中Pb2＋的吸附
Adsorption of Pb2+ from aqueous solution by walnut shell powder
摘要
Abstract
In this study, the adsorption of Pb^2+ from aqueous solution by walnut shell powder was investiga- ted. The effect of experimental parameters, such as sorbent size, dosage, pH and initial Pb^2+ concentration,as well as adsorption thermodynamics and kinetics were also examined. The results show that the removal efficiency increased with the decreasing sorbent size, increasing sorbent dosage and initial Pb2+ concentration. Under opti- mized conditions, 0 - 0.3 mm 15 g/L sorbent could remove 96.98% of Pb2 + from 50 mL 50 mg/L Pb^2+ solution at pH = 5 and 298 K. The experimental data closely followed Sips isotherms, with adsorption capacity of 18.25, 18.27 and 20.94 mg/g at 283, 293 and 303 K, respectively. The overall adsorption process was exothermic, entropy reduced and spontaneous. The adsorption kinetics followed the pseudo-second order model, and the rate constant decreased with the increasing temperature. The adsorption equilibrium could be reached within 90 and 120 min at 293 and 303 K, respectively. Combined with FTIR and SEM methods, the process of adsorption Pb^2+ on walnut shell powder was found to be complex and dominated by physical adsorption, accompanied with minor ion exchange, chelation and intra-particle diffusion process.关键词
核桃壳粉/Pb^2＋/吸附/等温线/热力学/动力学Key words
walnut shell powder/Pb^2+/adsorption/isotherms/thermodynamics/kinetics分类
资源环境引用本文复制引用
许振,李云春,姜友军,孟令银..核桃壳粉对水溶液中Pb2＋的吸附[J].环境工程学报,2012,6(12):4504-4512,9.基金项目
四川省教育厅科研重点项目 （）
四川农业大学“大学生创新性实验计划”基金 （）
