Abstract:

Heavy metal complexes formed by heavy metals and organic complexing agents in industrial wastewater are one of the pollutants that are difficult to effectively remove by conventional water treatment methods. Although photocatalytic oxidation would be a candidate technically for complex degradation, the high recombination ratio of electron-hole pairs generated by TiO₂ limits the application. Microbial fuel cells could suppress recombination of pairs by applying a bias voltage to the photocatalytic unit, which ultimately manifests as an efficient decomplexation reaction. In this work, the coupling of MFC and photocatalytic oxidation was proven to be efficient to improve the removal of Cu-EDTA and Cu²⁺ simultaneously. The results show that the photocatalytic unit matched with single MFC, double MFC connected in series, and double MFC connected in parallel lifted the removal rate of Cu-EDTA up to 52.6%, 73.57%, and 61.54%, respectively, while the removal of Cu²⁺ went to 18.09 %, 36.87% and 21.09%. Accordingly, it was shown that the coupling with MFC connected in series could enhance the removal efficiency of the photocatalytic unit to a greater extent.

Key words: catalysis, complexes, photochemistry, microbial fuel cell, radical, Cu-EDTA

摘要：

工业废水中重金属与有机络合剂形成的重金属络合物是常规水处理方法难以有效去除的污染物之一。光催化氧化是降解水体中重金属络合物的有效方法，但纯TiO₂催化光生电子-空穴对的较高复合效率限制了该技术在降解重金属络合物方面的应用。微生物燃料电池(microbial fuel cell， MFC)可以通过对光催化氧化单元施加电势提升光生电子与空穴分离率的同时有效降低复合效率，最终表现为高效的破络合反应。本文将MFC与光催化氧化进行耦合，在提高Cu-EDTA破络合效率的同时去除Cu²⁺。结果表明单MFC、串联MFC与并联MFC三种耦合方式均能提高光催化单元对Cu-EDTA的去除率，去除率分别为52.6%、73.57%和61.54%；对Cu²⁺的去除效果分别为18.09%、36.87%和21.09%。说明串联MFC耦合方式可以更大程度发挥光催化单元的效率。

关键词: 催化（作用）, 配合物, 光化学, 微生物燃料电池, 自由基, Cu-EDTA