二氧化锰改性沸石对废水中Pb2+的吸附性能及其影响因素研究

改性后的沸石材料,可大幅度提高其对金属离子的吸附量,在治理环境污染方面具有巨大的潜力。高锰酸钾和硫酸锰反应生成的二氧化锰包裹在沸石表面,可大大提高其吸附性能,最终达到吸附废水中重金属的目的。研究了二氧化锰改性沸石对废水中Pb²⁺吸附性能的影响因素,如沸石与二氧化锰投料比、反应时间、溶液pH值、反应温度、Pb²⁺初始浓度等,并探讨了其吸附机理。试验结果表明:二氧化锰改性沸石对废水中Pb²⁺的吸附效果随着沸石与二氧化锰投料比的增加而提高,平衡吸附时间为12 h,吸附反应的最佳溶液pH值为5~6;二氧化锰改性沸石对废水中Pb²⁺的吸附为自发的吸热反应,吸附过程符合Langmuir等温吸附模型,说明为单配体吸附模式;红外光谱分析发现,-OH是影响二氧化锰改性沸石吸附废水中Pb²⁺的主要官能团;低浓度腐殖酸对二氧化锰改性沸石吸附废水中Pb²⁺的影响较小,不产生竞争吸附。

Adsorption of Pb2+ in Wastewater by Manganese Dioxide- modified Zeolite and Influencing Factors

The modified zeolite material can greatly improve its adsorption capacity to metal ions and has great potential in environmental pollution control.The manganese dioxide formed by the reaction of potassium permanganate and manganese sulfate is wrapped on the surface of zeolite,which can greatly improve its adsorption capacity,and finally achieve the purpose of adsorbing heavy metal.This paper explores the factors affecting the adsorption performance of zeolite modified by manganese dioxide,such as ratio of zeolite to manganese dioxide,reaction time,pH of solution,reaction temperature,and initial concentration of Pb²⁺,and further discusses the adsorption mechanism.The experiments show that the adsorption effect of the modified zeolite is improved with the increase of the ratio of zeolite to manganese dioxide,the equili-brium adsorption time is 12 h,and the optimal solution pH value of adsorption reaction is between 5 and 6.The adsorption of Pb²⁺by zeolite modified by manganese dioxide is a spontaneous endothermic reaction.The endothermic reaction is in accordance with Langmuir isothermal adsorption model,indicating a monoligand adsorption model.It is found by infrared spectroscopy that oxhydryl is the main functional group which affects the Pb²⁺adsorption in wastewater by the modified zeolite.Humic acid has little effect on Pb²⁺adsorption of modified zeolite and there isn’t competitive adsorption during the process.