Carwash wastewater treatment through the synergistic efficiency of microbial fuel cells and metal-organic frameworks with graphene oxide integration

Abstract

This study explored the effectiveness of integrating Microbial Fuel Cells (MFC) with Metal-Organic Frameworks (MOF) enhanced by graphene oxide as a unique approach for carwash effluent treatment. The research encompassed three key components: analyzing MFC in isolation, evaluating MOF alone, and studying the combined MFC and MOF approach. The results demonstrated that the simultaneous use of MOF and MFC led to significant improvements in pollutant removal, indicating a synergistic effect on various pollutants within the wastewater. In retrospect, the MFC displayed low power density (0.095 mW/m2) and current density (2.8 mA/m2) during the initial 2 hours. However, a significant increase occurred, peaking at 46.2 mA/m2 and 21.62 mW/m2 by the 18th hour. Although current density decreased thereafter, power density stayed relatively high, indicating stabilization of microbial activity. The 48-h experiment concluded with 17.4 mA/m2 and 11.28 mW/m2. Notably, the combined MOF and MFC treatment consistently outperformed individual treatments, especially in the removal of heavy metals like zinc, nickel, and cadmium, with zinc removal rates increasing from 92.6 % to 96.5 %. In terms of organic contaminants, the integrated treatment approach achieved a remarkable 99.2 % removal of Biochemical Oxygen Demand (BOD). Moreover, the integrated treatment approach achieved a remarkable 100 % removal efficiency for turbidity and TSS, resulting in improved water clarity due to better fine suspended particle removal facilitated by MFC. The findings suggest that the combination of MOF and MFC holds great potential for comprehensive wastewater treatment, effectively eliminating a range of contaminants, including organic compounds, heavy metals, and general water quality parameters. The practical application of this integrated method can be further optimized and expanded through additional research and system refinement.

Keywords

• Microbial fuel cells
• Metal-organic frameworks
• Carwash wastewater
• Wastewater treatment
• Graphene oxide