Microbial fuel cells (MFCs) are the efficient and sustainable approach for the removal of toxic metals and generate energy concurrently. This article highlighted the effective use of rotten rice as an organic source for bacterial species to generate electricity and decrease the metal concentrations from wastewater. The obtained results were corresponding to the unique MFCs operation where the 510 mV voltage was produced within 14-day operation with 1000 Ω external resistance. The maximum power density and current density were found to be 2.9 mW/m2 and 168.42 mA/m2 with 363.6 Ω internal resistance. Similarly, the maximum metal removal efficiency was found to be 82.2% (Cd), 95.71% (Pb), 96.13% (Cr), 89.50% (Ni), 89.82 (Co), 99.50% (Ag), and 99.88% (Cu). In the biological test, it was found that Lysinibacillus strains, Chryseobacterium strains, Escherichia strains, Bacillus strains are responsible for energy generation and metal removal. Furthermore, a multiparameter optimization revealed that MFCs are the best approach for a natural environment with no special requirements. Lastly, the working mechanism of MFCs and future recommendations are enclosed.
Benthic microbial fuel cell (BMFC) is the most promising type of bioelectrochemical approach for producing electrons and protons from natural organic waste. In the present work, a single-chamber BMFC was used, containing sago (Cycas revoluta) waste as the organic feed for microorganisms. The local wastewater was supplemented with heavy metal ions (Pb2+, Cd2+, Cr3+, Ni2+, Co2+, Ag+, and Cu2+) and used as an inoculation source to evaluate the performance of BMFC against the toxic metal remediations. According to the experimental results, the maximum power density obtained was 42.55 mW/m2 within 25 days of the BMFC operation. The maximum remediation efficiency of the metal ion removal from the wastewater was found to be 99.30% (Ag+). The conductive pili-type bacteria species (Acinetobacter species, Leucobacter species, Bacillus species, Proteus species. and Klebsiella pneumoniae) were found in the present study during isolation and identification processes. This study's multiple parameter optimization revealed that pH 7 and room temperature is the best condition for optimal performance. Finally, this study included the mechanism, future recommendations, and concluding remarks.