Design and Analysis of a Photocatalytic Microbial Fuel Cell System Using a C-TiO₂ Anode for the Synergistic Treatment of Composite Pollution in Mine Water and Power Generation

Abstract

Mine drainage is a typical type of wastewater generated throughout mining activities, which commonly contains persistent organic contaminants represented by bisphenol A, as well as heavy metal ions including iron, manganese and zinc. Improper discharge and treatment of such wastewater will lead to severe ecological environmental pollution and massive waste of available water resources. Although traditional wastewater treatment techniques are capable of eliminating partial pollutants from mine drainage, they are restricted by inherent defects such as high energy consumption, expensive operating cost and low resource recycling efficiency. Microbial fuel cells (MFCs) can realize in-situ electricity generation relying on microbial biodegradation of organic pollutants, achieving synchronous pollutant removal and energy recovery. Nevertheless, the practical application of conventional MFCs is still hindered by unsatisfactory power output, mainly stemming from low interfacial electron transfer efficiency and inferior long-term system stability. Targeting these key technical limitations, this work constructs a novel double-layer eight-chamber MFC system integrated with TiO₂ photocatalysis technology. The double-layer eight-chamber structural design effectively enlarges the overall reaction space of the reactor and accelerates the electron transfer rate inside the system. Moreover, the introduced TiO₂ photocatalysis module further improves the degradation efficiency of refractory organic compounds and the removal capacity of coexisting heavy metals. The systematic analysis on reactor structure configuration, internal working mechanism and pollutant removal pathways demonstrates that the integrated hybrid system can efficiently purify mine drainage polluted jointly by bisphenol A and heavy metals, while achieving stable bioelectricity generation. This research provides a novel feasible technical solution for harmless treatment and resource reuse of mine drainage, as well as theoretical and technical support for the construction of green and low-carbon mining ecosystems.