膨润土复合新型吸附剂处理含Mn^(2+)废水

Removal of Mn^(2+) in wastewater with new adsorbent of composite bentonite

针对废水中Mn2+难去除问题,利用经高温焙烧制备的膨润土-粉煤灰复合新型吸附剂对废水中的Mn2+进行吸附处理实验研究。研究了新型吸附剂在不同的吸附时间、pH、初始Mn2+浓度条件下对Mn2+的吸附去除效果影响、Fe2+、Mn2+共存时竞争吸附特性以及吸附Mn2+的吸附性能和反应动力学。实验结果表明,新型吸附剂处理Mn2+浓度为35 mg/L的废水,在温度25℃、转速100 r/min、投加量20 g/L、吸附时间120 min、pH≥7时反应条件最佳,Mn2+的去除率均可达到90%以上;Fe2+、Mn2+共存时,存在竞争吸附,Fe2+会被优先选择吸附去除,Fe2+的存在会影响Mn2+的去除效果;膨润土复合新型吸附剂对Mn2+的吸附行为符合Langmuir等温吸附模型和准二级动力学模型。新型吸附剂对废水中的Mn2+有很好的去除效果,而且能有效解决膨润土不易固液分离问题,可作为含Mn2+废水高效、廉价、环保的水处理吸附剂。

For the problem of Mn2+ removal in wastewater,the research was carried out by using new adsorbent of composite bentonite-fly ash calcined at high temperature to adsorb Mn2+ in wastewater. We studied the adsorption effect of new adsorbent on Mn2+ at different adsorption times,pH values,initial Mn2+ concentrations,and the adsorption competitive characteristics of coexistence of Fe2+ and Mn2+. We also studied the adsorption performance and reaction kinetics of Mn2+ adsorption. Results showed that the optimum reaction conditions of new adsorbent to absorb initial concentration of Mn2+ 35 mg /L in wastewater could be acquired at 25℃,rotational speed of 100 r /min,adsorbent dosage of 20 g /L,adsorption time of 120 min,pH value greater than or equal to 7.Under the conditions,the efficiency of removing Mn2+ could reach up to 90%. There was a competitive adsorption phenomenon as the coexistence of Fe2+ and Mn2+. Fe2 +was removed prior to Mn2+ because the removal effect of Mn2+was affected by the presence of Fe2+. The adsorption behavior of new adsorbent of composite bentonite-fly ash for Mn2+ was identical with the Langmuir model and the second order kinetic model. Mn2+ in wastewater was removed efficiently by using the new adsorbent,and the problem of the solid-liquid separation of bentonite was also solved well. The new adsorbent can be the efficient,cheap,environmentally friendly water treatment material for Mn2+ removal in wastewater.