离子交换树脂对锰离子的吸附特性及工艺优化

Adsorption Characteristics and Technology Optimization of Ion Exchange Resin for Manganese Ion

采用MV860离子交换树脂处理含锰废水,研究了树脂对Mn^2+的吸附行为及热力学、动力学过程,并运用响应曲面法探讨了流速、水中Mn^2+含量、pH对树脂吸附量的影响规律,优化了吸附条件。结果表明,在温度293K、转速180 r/min的静态吸附实验中,MV860树脂对Mn^2+的饱和吸附量为12.55 mg/g,可实现锰的回收利用。树脂对Mn^2+的吸附过程遵循准1级动力学方程,颗粒扩散为吸附的主要控制步骤,吸附过程与Langmuir等温吸附方程较为吻合,为单分子层化学吸附。各吸附条件对动态吸附量的影响依次为Mn^2+含量>流速,pH对吸附量的影响不大,吸附Mn^2+的优化条件为:水样浓度3 g/L、流速4.2 BV/h,该条件下的动态吸附量为12.42 mg/g,与预测值基本相符。

The manganiferous wastewater was treated by MV860 ion exchange resin.The adsorption behavior,thermodynamics and kinetics process of resin for Mn^2+were investigated.The Box-Behnken response surface methodology was used to discuss the influence law of the flow rate,Mn^2+content in water and pH on resin adsorption capacity,and the adsorption technological conditions had been optimized.The result showed that,saturated adsorption capacity of MV860 resin for Mn^2+was 12.55 mg/g in the static adsorption experiment,keeping the temperature at 293 K and rotating at 180 r/min,and it could realize the recovery of manganese.The adsorption process of Mn^2+by resin could be described in terms of pseudo-first order kinetics.The ratelimiting step was mainly controlled by particle diffusion.The adsorption process of the resin followed the Langmuir isothermal model better,which belongs to single molecule layer chemical adsorption.The order of the factors was as follows:Mn^2+content,flow rate.However,the pH had not significant effect on the adsorption capacity.The optimal adsorption conditions for Mn^2+were water sample concentration of 3 g/L,flow rate of 4.2 BV/h,with a dynamic adsorption capacity for resin was 12.42 mg/g,which was consistent with the predictive value.