电化学还原去除水中含氧酸根离子研究进展

Advances in Electrochemical Reductive Removal of Oxyanions in Water

含氧酸盐(硝酸盐、溴酸盐、高氯酸盐等)污染物大量排放造成的水体污染问题越来越严重.含氧酸根离子具有持久性、难降解性、致畸性和致癌性,对生态系统和人类健康造成极大威胁,从而引起了全球的广泛关注.电化学还原技术(electrochemical reduction,ER)可以利用电子或者活化水分子产生的强还原性物种——原子氢(H*),实现水中有毒含氧酸根离子的高效、绿色、安全去除,被认为是极具发展前景的水处理技术之一.首先简要介绍了电化学还原去除水中含氧酸根离子的机理,随后重点综述了电化学还原硝酸根、溴酸根、高氯酸根的研究进展,讨论了不同环境中电化学还原去除含氧酸根离子的反应路径,分析了催化剂结构和种类等对电化学还原含氧酸根离子的影响.最后,探讨和展望了电化学还原去除水中含氧酸根离子面临的挑战.

The excessive discharge of oxyanions(i.e.,nitrate,bromate,perchlorate)into water has caused more and more serious environmental pollution problems.Oxyanions are generally persistent,refractory,teratogenic and carcinogenic,posing a great threat to ecosystems and human health.Therefore,they have increasingly attracted widespread attention.Electrochemical reduction is regarded as one of the most promising water treatment technology,because it could employ either electrons or strong reductive species(atomic H*)generated by dissociating water molecules to realize the efficient,green and safe removal of toxic oxyanions.Herein,the electrochemical reduction mechanism for removing pollutants is briefly introduced,the advancements of electrochemical reduction of nitrate,bromate and perchlorate are summarized and their possible reaction pathways are discussed,the effect of catalysts(i.e.,structure,types)on the performance of electrochemical reduction is further analyzed.Finally,the possible challenges of electrochemical reduction technology to remove oxyanions are deeply discussed and prospected.