花生壳活性炭对Cr(Ⅵ)的吸附性能

摘要

研究了花生壳活性炭对水溶液中Cr(Ⅵ)的吸附性能.结果表明,花生壳活性炭对Cr(Ⅵ)具有良好的吸附作用.常温下,0.1g花生壳活性炭,对20 mL pH为1.5,ρ[ Cr(Ⅵ)]为20.0 mg/L溶液,振荡吸附120 min,Cr(Ⅵ)的去除率可达98.68％.花生壳活性炭对Cr(Ⅵ)的吸附符合Freun-dlish吸附等温方程和一级动力学方程.吸附过程的自由能变△G＜0,焓变△H＞42 kJ/mol,熵变△S＞0,说明花生壳活性炭对Cr(Ⅵ)的吸附为自发的吸热化学过程.%Adsorption performance of activated carbon made from peanut shells for Cr( VI) in aqueous solution was studied. Results showed that the activated carbon had a good adsorption function to Cr( VI). At room temperature,the removal efficiency of 0. 1 g activated carbon could up to 98. 68% under 120min vibration time for 20 mL solution in which the Cr( VI) concentration was 20. 0mg/L and pH was 1.5. The adsorption behavior of the activated carbon for Cr( VI) was in accord with the Freundlish adsorption isotherms equation and first-order kinetics model. In the adsorption process;Gibbs free energy changes AG < 0,enthalpy changes △H >42 kJ/mol and entropy changes AS >0, which indicated that this adsorption process was a spontaneous endothermic chemical process.