基于聚苯胺的电吸附法处理含铅离子废水的研究

Treatment of Wastewater Containing Lead Ions Based on the Electrosorption by Polyaniline

采用化学氧化聚合法合成聚苯胺(PANI),并对其进行了红外光谱和扫描电镜表征。以PANI为电极材料,通过电吸附技术去除模拟废水中的Pb2+;同时PANI链上富含的亚氨基还可以与Pb2+发生络合,从而提高了PANI电吸附去除Pb2+的效率。研究了吸附电位、吸附时间、初始浓度等因素对Pb2+去除效果的影响,并且分别从动力学与热力学的角度研究了PANI对Pb2+的电吸附。结果表明,PANI电极对Pb2+的电吸附过程符合Lagergren准一级动力学方程和Freundlich吸附等温式。最后,对吸附了Pb2+的PANI电极的脱附再生进行了研究,经过多次电吸附-脱附循环后,PANI电极对Pb2+的去除率并无明显降低。因此通过电吸附技术,用PANI电极去除实际废水中的Pb2+具有可行性。

Polyaniline （PANI） was synthesized by chemically oxidative polymerization approach,and characterized by FT-IR spectra and scanning electron microscopy （SEM）.The obtained PANI was used as electrode material for the removal of Pb2＋ in simulated wastewater via electrosorption; meanwhile,the imino groups on PANI chains could chelate with Pb2＋,which enhanced the removal efficiency of Pb2＋.In this work,the effect of adsorption potential,adsorption time and the initial concentration on Pb2＋ removal were discussed,and the kinetic and thermodynamic investigation of Pb2＋ electrosorption by PANI was also performed.The results indicated that the electrosorption of Pb2＋ by the PANI electrode was well described by the Lagergren pseudo-first-order model and the Freundlich isotherm model.Finally,desorption experiments were carried out to investigate the regeneration of the PANI electrode with Pb2＋ adsorbed,and the results showed that the decrease in the removal ratio of Pb2＋ was not obvious after several electrosorption-desorption cycles,indicating the possibility of Pb2＋ removal from practical wastewater by electrosorption with the proposed PANI electrode.