柠檬酸改性白酒糟对Cu、Cd、Cr和Pb的吸附特性研究

Adsorption characteristics of Cu,Cd,Cr and Pb onto distillers’grains modified by citric acid

以柠檬酸改性白酒糟为吸附剂,考察了pH值、吸附剂投加量、反应时间、吸附质初始浓度等对水中Cu、Cd、Cr和Pb吸附性能的影响,探究了改性白酒糟的等温吸附及吸附动力学特性。结果表明,相对最优的实验条件为pH=4,吸附剂投加量4 g/L,反应时间3 h,吸附质初始浓度60 mg/L;改性白酒糟对Cu、Pb、Cd、Cr的吸附过程更符合准二级动力学方程和Langmuir等温线方程,计算得到理论最大吸附量为Cu 11.19 mg/g,Cd 7.49 mg/g,Cr 5.63 mg/g,Pb 9.36 mg/g。

With distillers’grains modified by citric acid as adsorbent,the effects of pH,adsorbent dose,contact time and initial adsorbate concentration on the adsorption capacity of four heavy metals(Cu,Cd,Cr and Pb),the adsorption isotherm and kinetics of modified distillers’grains were both investigated in present study.The results showed that the optimal condition of adsorption experiment are pH=4,4 g/L of modified distillers’grains dose,3 h of contact time and 60 mg/L of initial heavy metals concentration,the adsorption kinetics of four heavy metals could be described commendably by the pseudo-second order model,the equilibrium experimental data were more correlated with the Langmuir isotherm equation,and the corresponding maximum adsorption capacity were 11.19 mg/g of Cu,7.49 mg/g of Cd,5.63 mg/g of Cr,9.36 mg/g of Pb onto modified distillers’grains respectively.