Performance of tubular microbial fuel cells using different industrial wastewater

Abstract

Microbial fuel cells (MFCs) can potentially ameliorate the extensive use of energy in the biological treatment step of wastewater treatment, among other benefits. This paper investigated the use of MFCs for different types of industrial wastewater using carbon fuel cell electrodes. The MFCs were inoculated with activated sludge and operated with industrial wastewater collected from Kuwait's most common industries (dairy, detergents, petrochemicals, and soft drinks). The results showed that MFCs have successively generated electricity from all industrial wastewater, except for that from the petrochemical industry. The MFCs achieved a maximum power density of 86 mW/m3 (dairy wastewater), 41 mW/m3 (detergents wastewater), 20 mW/m3 (soft drink wastewater), and 1 mW/m3 (petrochemical wastewater). Furthermore, the MFCs achieved an average Chemical Oxygen Demand (COD) removal efficiency of 75 % (dairy wastewater), 44 % (detergent wastewater), 7 % (petrochemical wastewater), and 79 % (soft drink wastewater). Conceivably, these removal rates correspond to bioelectrochemical utilization of the organic matter present in the different types of industrial wastewater to produce energy. Increasing batch duration from 7 to 14 days did not influence nutrients and heavy metals removal. In addition, it was found that the application of MFCs for petrochemical wastewater treatment was influenced by (high COD level = 15,114 mg/L), the content of inhibitive chemicals (such as surfactant, dimethylpolysiloxane, ferric sulfate, and benzalkonium chloride), and the hydrophobicity of the organics leading to deterioration in fuel cell electrode performance, catalyst deactivation, and generally unfavourable microbial growth conditions.