聚苯胺修饰电极去除水中高氯酸根

在三电极体系中,研究聚苯胺修饰电极对高氯酸根离子的电化学去除。基于导电高聚物的电控离子交换特性,在其电化学扫描过程中高氯酸根能够掺杂进入到聚苯胺高分子链。在0.10 mol/L Na2SO4 (pH 4.0)电解液中电化学循环伏安扫描25 min,2 mg/L高氯酸根的去除率达96.5%;在相同处理时间内,去除率随高氯酸根浓度的增加而明显降低,且溶液pH在3到5的范围内得到最优的去除效果。通过红外光谱和X射线光电子能谱表征高氯酸根掺杂前后的聚苯胺膜,结合循环伏安图的分析提出高氯酸根去除过程中可能的反应机理:高氯酸根作为掺杂离子,随电位的改变在聚苯胺链中迁移。研究表明,基于聚苯胺的电控离子交换特性,可以开发一种绿色高效的高氯酸根去除技术。

Electrochemical removal of perchlorate ion by polyaniline modified electrode

The electrochemical removal of perchlorate ion(ClO4-) was investigated in a three-electrode system using polyaniline(PANI) as the electrode material.Perchlorate ion removal was observed during electrochemical treatment based on electrically switched ion exchange(ESIX) of PANI film.The removal efficiency of 2 mg/L ClO4- in 0.10 mol/L Na2SO4 supporting electrolyte achieved 96.5% at pH 4 in 25 min.However,as the concentration of perchlorate increased,the removal efficiency declined markedly.The optimal removal was found in pH range of 3-5.The PANI film before and after the removal of perchlorate was characterized by FTIR and X-ray photoelectron spectra.The electrochemical reaction mechanism was discussed by analyzing the cyclic voltammograms.The mechanism was proposed that perchlorate migrates in and out of the polymer as doping anion in the electrochemical removal process.The results of the present study point to the possibility of developing a green process for removing ClO4- from wastewater using this thin film through ESIX.