ABSTRACT
The microbial fuel cell (MFC) is considered a modern technology used for treating wastewater and recovering electrical energy. In this study, a new dual technology combining MFC and a specialized biofilter was used. The anodic materials in the system were crushed graphite, either without coating (UFB-MFC) or coated with nanomaterials (nano-UFB-MFC). This biofilter served as a barrier to retain and remove turbidity and suspended solids, while also facilitating the role of bacteria in the removal of organic pollutants, phosphates, nitrates, sulfates, oil and greases. The results demonstrated that both systems exhibited high efficiency in treating kitchen wastewater, specifically greywater and dishwashing wastewater with high detergent concentrations. The removal efficiencies of COD, oil and grease, suspended solids, turbidity, nitrates, sulfates, and phosphates in first UFB-MFC were found to be 88, 95, 89, 86, 87, 75, and 94%, respectively, and in Nano-UFB-MFC were 86, 99, 95, 91, 81, 88, and 95%, respectively, with a high efficiency in recovering bioenergy reaching a value of 1.8 and 1.5 A m-3, respectively. The results of this study demonstrate the potential for developing MFC and utilizing it as a domestic system to mitigate pollution risks before discharging wastewater into the sewer network.
ABSTRACT
Carwash garages are worldwide cleaning facilities. Discharge of their untreated or improperly treated wastewaters highly contributes to the pollution of water resources. Sodium dodecyl sulfate (SDS), a widely used anionic surfactant in the carwash shampoos represents the major constituent of the carwash wastewater. In this study, a new configuration of three-dimensional MFC packed with irregular shaped graphite granules to support and join the plain anodes in the anodic section. The performance of the 3D-MFC was evaluated in two operational modes; continuous and batch. The evaluation was carried out mainly in terms of the removal efficiency of organic content, in particular SDS as well as oil and grease associated with bioenergy generation from actual carwash wastewater used to fuel the MFC. The results demonstrated that maximum removal efficiencies of COD, SDS, and oil and grease were 87%, 88%, and 90%, respectively. Also, the results demonstrated that during the continuous mode operation maximum current density and power output were 1786 mA/m3 and 482 mW/m3, respectively. At batch operation mode, the maximum current density and power output were 1793 mA/m3 and 478 mW/m3, respectively indicating that the performance of the 3D-MFC was comparable in both operation modes.