基于耦合电氧化-还原的反应性电化学膜工艺处理高含氯难处理工业废水

Treatment of high chlorine-containing refractory industrial wastewater using reactive electrochemical membrane coupled with electro-oxidation and reduction processes

由于传统以生化为主的处理工艺通常难以有效去除工业废水中难降解有机物,出水通常无法满足排放标准及回用需求,因此,本研究从电极材料、处理效能、副产物生成与抑制等全面评估了新型反应性电化学膜(REM)技术处理含氯量高的难降解工业废水的可行性。结果表明,在Ti_(4)O_7和SnO_(2)-Sb 2种常见的电极材料中,SnO_(2)-Sb REM阳极对有机物的去除率比Ti_(4)O_7 REM阳极高约9%~17%。光谱分析结果表明,废水中的腐殖酸类物质、芳香族化合物和共轭大分子均能够被有效氧化分解。在氧化机理方面,高浓度Cl-的淬灭作用削弱了氧化过程中^(·)OH的贡献,原始有机物首先主要通过直接电子转移(DET)过程被分解,随后DET过程与生成的活性氯结合实现了废水的进一步氧化。进一步开发的耦合电氧化和还原过程的反应性电化学膜系统可有效去除有机物并抑制ClO_(3)^(-)和ClO_(4)^(-)的生成,处理4 h之后,出水的COD稳定在80 mg·L^(-1),ClO_(3)^(-)和ClO_(4)^(-)分别稳定在90 mg·L^(-1)和0.25·mg·L^(-1)。该系统的出水符合中国的处理规定的情况下,所需电能仅为7.91 kWh·m^(-3),同时废水中的NH_(4)^(+)-N和NO_(3)^(-)-N的去除率也达到100%。以上研究结果表明,反应性电化学膜技术是一项具备前景的处理高含氯量难处理工业废水的技术。

Traditional biochemical-derived treatment processes struggle to effectively remove refractory organic matter from industrial wastewater,and the effluents often fail to meet discharge standards and reuse requirements.In this study,the feasibility of employing a novel reactive electrochemical membrane(REM)technique to treat industrial wastewater containing high levels of chlorine was assessed in terms of electrode material,treatment efficiency,byproduct generation and inhibition.The results indicated that among the commonly used electrode materials,SnO_(2)^(-)Sb REM anodes exhibited an approximately 9%~17%higher removal rate of organic matter than Ti 4O7 REM anodes.Spectroscopic analysis indicated effective oxidation of humic acids,aromatic compounds,and conjugated macromolecules.During the oxidation process,the quenching effects of high concentrations of chloride ions(Cl‒)weakened the contributions of^(·)OH radicals.As a result,the original organic compounds were primarily decomposed through direct electron transfer(DET).Subsequently,the DET process combined with the generated active chlorine realized further wastewater oxidization.The developed REM system,which coupled electrooxidation and reduction processes,could effectively remove organic matter and suppress the generation of ClO_(3)^(-)and ClO_(4)^(-).After 4 h treatment,the effluent COD stabilized at 80 mg·L^(−1),and ClO_(3)^(-)and ClO_(4)^(-)stabilized at 90 mg·L^(−1) and 0.25 mg·L^(−1),respectively.With energy consumption of only about 7.91 kWh·m−3,the effluent could meet China’s discharge regulations,and 100%removal of NH_(4)^(+)-N and NO_(3)^(-)-N from the wastewater occurred.Overall,the above results indicated that REM system is a promising technique for treating refractory industrial wastewater with high chlorine content.