PSSMA修饰磁性氧化石墨烯对Pb2+、Cu2+ 的吸附性能

以氧化石墨烯(GO)、FeCl_3·6H_2O及聚(4-苯乙烯磺酸-共聚-马来酸)钠盐(PSSMA)为主要原料,通过简便一步溶剂热法制备了阴离子聚电解质修饰磁性氧化石墨烯(MGO@PSSMA),并将其用于水溶液中重金属Pb~(2+)、Cu~(2+)的吸附去除。采用FTIR、SEM、TEM、VSM和DLS对制备的MGO@PSSMA进行了表征。考察了溶液pH、吸附时间、溶液初始质量浓度对Pb~(2+)、Cu~(2+)在MGO@PSSMA及未经PSSMA修饰磁性氧化石墨烯(MGO)上吸附的影响。探讨了吸附等温过程、吸附动力学及吸附作用机理。结果表明:MGO表面引入PSSMA可有效增加其对Pb~(2+)、Cu~(2+)的吸附量。在pH=5,溶液初始质量浓度为300 mg/L时,MGO@PSSMA对Pb~(2+)和Cu~(2+)的实际吸附量达141.1和104.8 mg/g。当溶液初始质量浓度为150 mg/L时,MGO@PSSMA对Pb~(2+)和Cu~(2+)的吸附平衡时间分别为2和1.5 min。MGO@PSSMA对Pb~(2+)、Cu~(2+)的吸附动力学及吸附等温数据分别符合准二级吸附动力学模型和Langmuir吸附等温模型。使用乙二胺四乙酸(EDTA)和HCl可实现MGO@PSSMA的有效再生;通过外加磁场作用可实现MGO@PSSMA的回收再利用。

Adsorption performance of PSSMA-modified magnetic graphene oxide toward Pb(II) and Cu(II) ions

A novel anionic polyelectrolyte poly(4-styrenesulfonic acid-co-maleic acid) sodium (PSSMA) decorated magnetic graphene oxide (MGO@PSSMA) was prepared by a simple and facile one-step solvothermal method in this paper, and used for the removal of heavy metal lead (Pb(II)) and copper ions (Cu(II)) from aqueous solution. The prepared MGO@PSSMA was characterized by FTIR, SEM, TEM, VSM and DLS. Batch adsorption studies were performed to investigate the effects of solution pH, adsorption time and initial solution concentration on the adsorption of Pb(II) and Cu(II) onto MGO@PSSMA and MGO without modifying with PSSMA, and the adsorption isotherms, kinetics and mechanism were also studied. The obtained results show that the introduction of PSSMA onto MGO can dramatically enhance the adsorption of Pb(II) and Cu(II) onto MGO@PSSMA, the adsorption capacities are changed from 24.9 mg/g to 141.1 mg/g for Pb(II) and from 22.8 mg/g to 104.8 mg/g for Cu(II), respectively. Moreover, the adsorption of Pb(II) and Cu(II) onto MGO@PSSMA and MGO fits pseudo-second-order kinetic and Langmuir model well, respectively. In addition, the used MGO@PSSMA can be effectively regenerated with ethylenediaminetetraacetic acid (EDTA) and hydrochloric acid (HCI), and recovered from Pb(II) and Cu(II) aqueous solution under an external magnetic field.