竹炭/壳聚糖复合吸附剂对银（I）的吸附性能与回收研究

摘要

The kinetic and the thermodynamic parameters were studied for adsorption of the complex absorbent of bamboo charcoal/chitosan(BCCTS) for silver (I) in aqueous solution. And the recovery tests of silver(I) were also studied. Results of kinetics showed that adsorption of the BCCTS for silver(I) can deal with pseudo first-order reaction with the apparent adsorption activation energy of Ea=29.2 kJ/mol. The apparent adsorption rate constants and activated energy were determined at different temperature. Results of thermodynamics showed that the adsorption behavior of the BCCTS for silver (I) obeys the Langmuir isotherm model. The heat of adsorption∆H=40.8 kJ/mol, it means that the sorption process is a endothermic process, and the sorption process is mostly chemical adsorption. ∆G<0 means that the sorption process is a spontaneous process. The tests of adsorption recovery showed that the complex absorbent can be applied to the recovery of silver.%研究了竹炭/壳聚糖复合吸附剂吸附银(I)的动力学和热力学，并进行了银的回收实验。动力学实验表明，复合吸附剂对银(I)的吸附符合准一级动力学方程，测定不同温度下复合吸附剂对银(I)吸附的表观速率常数，得到表观活化能 Ea=29.2 kJ/mol；热力学研究表明，复合吸附剂对银(I)的吸附符合Langmuir等温吸附方程，测得吸附热∆H为40.8 kJ/mol，说明复合吸附剂对银(I)的吸附过程为吸热过程，吸附过程主要为化学吸附，吉布斯自由能∆G＜0，表明吸附质从溶液到吸附剂表面的吸附过程是自发过程。吸附回收实验表明：竹炭/壳聚糖复合吸附剂能应用于银的回收。