粉煤灰吸附处理Cd2+废水的动力学和热力学研究

Kinetics and Thermodynamics of Adsorption of Cd2+ by Fly Ash

以固体废弃物粉煤灰为吸附剂材料,利用硝酸镉试剂模拟含Cd^2+废水,重点探讨了粉煤灰对Cd^2+的吸附动力学和热力学行为。结果表明,粉煤灰对Cd^2+的吸附动力学过程符合准二级动力学模型,主要以化学吸附为主;等温吸附过程符合Freundlich等温吸附模型;热力学结果表明该吸附过程为一自发进行的熵增吸热过程。

In this paper,solid waste fly ash were used as adsorbent materials. The cadmium nitrate reagent was used to simulate the wastewater containing Cd^2+. The adsorption kinetics and thermodynamics behavior of Cd^2+ onto fly ash were mainly discussed. The pseudo-second-order model provided the best fitting for the adsorption kinetics of Cd^2+ onto fly ash,indicating the adsorption was mainly chemical. The adsorption isotherm was fitted well with the Freundlich model. Thermodynamics analysis indicated that Cd^2+ adsorption onto fly ash was spontaneous,entropy increase and endothermic process.