马来酸酐改性聚乙烯醇对水体中Pb2+的吸附行为

通过羟基的酯化反应并采用浓硫酸进行碳化处理,制备了马来酸酐改性聚乙烯醇,通过FTIR对其化学结构进行了表征,并研究了改性聚乙烯醇对水体中Pb^2+的吸附行为及重复使用性能。研究结果表明,改性后的聚乙烯醇表面基团结构发生了变化,成功引入了大量的—COOH;另外,其结构上呈现出大量的孔洞结构和更大的比表面积,使其与金属离子具有更多吸附位点和更强的络合能力。静态吸附结果表明,在吸附时间为60 min、pH为5.0、改性聚乙烯醇用量为0.10 g的条件下,改性聚乙烯醇对Pb^2+的饱和吸附量为287.3 mg/g,符合Langmuir等温吸附模型。通过吸附-脱附实验发现,马来酸酐改性聚乙烯醇吸附Pb2+时,具有良好的重复使用性能。

Adsorption Behavior of Pb^2+in Environmental Wastewater by Polyvinyl Alcohol Modified by Maleic Anhydride

The maleic anhydride modified polyvinyl alcohol was prepared by esterification of hydroxyl group and carbonization with concentrated sulfuric acid.Its chemical structure was characterized by FTIR,and the adsorption behavior and reusability of modified polyvinyl alcohol for Pb^2+in environmental wastewater was studied.The results showed that the surface group structure of the modified polyvinyl alcohol had changed,and a large number of—COOH had been successfully introduced.And the micromorphology indicated the modified polyvinyl alcohol had a large number of pore structure and large specific surface area,so that it had more adsorption sites and stronger complexation ability with metal ions.Static adsorption results showed that the saturated adsorption capacity of modified polyvinyl alcohol for Pb2+was found to be 287.3 mg/g at the conditions of pH=5.0,contact time of 60 min and an amount of modified polyvinyl alcohol of 0.10 g.The adsorption of Pb2+conformed Langmuir isothermal adsorption model.Furthermore,based on adsorption-desorption experiments,it was found that the maleic anhydride modified polyvinyl alcohol had good reusability when it was used to adsorb Pb^2+.