Abstract: Arsenic (As), a highly toxic metalloid, is commonly found in wastewater originating from mining, metallurgical processes, and pesticide production. Due to its bioaccumulative and carcinogenic nature, arsenic poses significant risks to both human health and environmental safety. In this study, simulated brown sugar wastewater was employed as the substrate, and As(Ⅲ)-containing wastewater was used as the anolyte to construct a dual-chamber microbial fuel cell (MFC). Based on the principle of anaerobic oxidation, we examined the effects of initial As(Ⅲ) concentration on the MFC’s output voltage and arsenic and COD removal rates. The results showed that at a substrate concentration of 2 g·L^-1, the MFC maintained a stable voltage for 35 hours, demonstrating optimal electricity generation performance. Under these conditions, an initial As(Ⅲ) concentration of 1 mg·L^-1 led to removal rates of 99.5% for As(Ⅲ) and 98.6% for As(T), outperforming the 85%-95% efficiency of current commercial adsorption-based arsenic removal technologies. At an initial As(Ⅲ) concentration of 2 mg·L^-1, the system exhibited peak power density and maximum COD removal rate. Scanning electron microscopy (SEM) revealed rod-like, block-like, and flake-like deposits on the anode carbon felt. X-ray photoelectron spectroscopy (XPS) analysis showed that As(Ⅴ) constituted 71.11% of total arsenic, indicating substantial oxidation of As(Ⅲ) to As(Ⅴ), which was adsorbed onto the carbon felt. These findings confirm the feasibility and effectiveness of the MFC system in removing arsenic via anaerobic oxidation. High-throughput sequencing identified Proteobacteria, Firmicutes, Azospirillum, and Clostridium_sensu_stricto_1 as the dominant microbial groups. Based on the primciple of anaerobic oxidation, this study achieres concurrent electricity generation and removal of both organic and inorganic pollutants, offering a novel and practical approach for treating arsenic-laden wastewater.

Key words: dual-chamber microbial fuel cell, anodic oxidation, As removal, power generation performance