磺酸苯偶氮石墨烯材料对重金属离子的吸附性能

Adsorption of heavy metal ions in water by4-chloro-3-sulfophenylazo graphene materials

将4-氯苯胺-3-磺酸接枝到RGO表面,合成新型苯偶氮功能化还原氧化石墨烯材料(RGOSPA),吸附水体中的Pb(Ⅱ)、Cu(Ⅱ)、Ni(Ⅱ)、Cd(Ⅱ)和Cr(Ⅲ)。实验显示RGOSPA吸附Pb(Ⅱ)和Cu(Ⅱ)溶液的最佳p H值为5. 0,吸附Ni(Ⅱ)、Cd(Ⅱ)和Cr(Ⅲ)的最佳p H值为5. 5,对Pb(Ⅱ)、Cu(Ⅱ)、Ni(Ⅱ)、Cd(Ⅱ)和Cr(Ⅲ)的最大吸附量分别为457. 4,60. 1,63. 7,186. 2,116. 1 mg/g。吸附动力学研究表明,RGOSPA在10 min达到平衡吸附量的80%,吸附过程符合准二级动力学方程。吸附等温线研究表明,与Freundlich模型相比,Langmuir模型更适合描述吸附过程。RGOSPA通过离子交换与配位达到对重金属离子的吸附效果,可作为去除重金属离子的良好吸附剂。

The synthesis of new sulfophenylazo reduced graphene oxide( RGOSPA) by grafting 4-chloro-3-sulfonic acid onto RGO surface by diazotization reaction and the adsorption properties of new materials were studied. The adsorption characteristics of Pb( Ⅱ),Cu( Ⅱ),Ni( Ⅱ),Cd( Ⅱ) and Cr( Ⅲ) in water show that the optimum pH value of adsorption Pb( Ⅱ) and Cu( Ⅱ) solutions were 5,and the best pH value for Ni( Ⅱ),Cd( Ⅱ) and Cr( Ⅲ) adsorption were 5. 5. The maximum adsorption capacity of RGOSPA for Pb( Ⅱ),Cu( Ⅱ),Ni( Ⅱ),Cd( Ⅱ) and Cr( Ⅲ) were 457. 4,60. 1,63. 7,186. 2,116. 1 mg/g,respectively. The adsorption kinetics showed that RGOSPA reached 80% of the equilibrium adsorption capacity in10 min,and the adsorption process conformed to the pseudo-second-order kinetic equation. The adsorption isotherm shows that Langmuir model is more suitable for describing adsorption process than Freundlich model. RGOSPA can adsorb heavy metal ions through ion exchange and coordination,and can be used as a good adsorbent for heavy metal ions removal.