ABSTRACT：Chlorine-mediated electrochemical advanced oxidation (Cl-EAO) technology is a promising approach for ammonia removal from wastewater due to its numerous advantages, including small infrastructure, short processing time, easy operation, high security, and high nitrogen selectivity. This paper provides a review of the ammonia oxidation mechanisms, characteristics, and anticipated applications of Cl-EAO technology. The mechanisms of ammonia oxidation encompass breakpoint chlorination and chlorine radical oxidation, although the contributions of active chlorine, Cl•, and ClO• remain uncertain. This study critically examines the limitations of existing research and suggests that a combination of determining free radical concentration and simulating a kinetic model would help elucidate the contributions of active chlorine, Cl•, and ClO• to ammonia oxidation. Furthermore, this review comprehensively summarizes the characteristics of ammonia oxidation, including kinetic properties, influencing factors, products, and electrodes. The amalgamation of Cl-EAO technology with photocatalytic and concentration technologies has the potential to enhance ammonia oxidation efficiency. Future research should concentrate on clarifying the contributions of active chlorine, Cl•, and ClO• to ammonia oxidation, the production of chloramines and other byproducts, and the development of more efficient anodes for the Cl-EAO process. The main objective of this review is to enhance the understanding of the Cl-EAO process. The findings presented herein contribute to the advancement of Cl-EAO technology and provide a foundation for future studies in this field.

KEYWORDS:Ammonia removal,Active chlorine, Chlorine radical, Electrochemical advanced oxidation, Anode, Water treatment

摘要：氯介导电化学高级氧化（Cl-EAO）具有占地面积小、处理效率高、操作简单，安全性好以及产物氮气选择性高等优势，是一种具有前景的废水脱氨技术。本文综述了Cl-EAO技术的氨氧化机理、特点及发展前景。在Cl-EAO体系中，氨氧化机理主要包括折点氯化机理和氯自由基氧化机理，但是氨氧化过程中活性氯、Cl•和ClO•的具体贡献仍不明确。本文批判性地指出了现有研究的局限性，并建议将自由基浓度定量和动力学模型模拟相结合以阐明活性氯、Cl•和ClO•对氨氧化的具体贡献。本文综述了该体系中氨氧化动力学特征、影响因素、副产物与电极等方面的特征，并指出将Cl-EAO技术与光催化和物理分离技术相结合能够提高氨氧化效率。本文提出，未来氯介导电化学高级氧化脱氮的研究应当更关注于阐明活性氯、Cl•和ClO•对氨氧化的机理、氯胺及其他含氯副产物的产生，以及新型阳极材料的开发等方面。本论文可以促进研究者们对Cl-EAO技术的了解，并为未来的相关研究提供参考。

关键词：氨去除，活性氯，氯自由基，电化学高级氧化，阳极，水处理

原载：Science of The Total Environment(2023 Impact Factor = 9.8)

原文链接：https://doi.org/10.1016/j.scitotenv.2023.165169