Evaluation of the effect of anolyte recirculation and anolyte pH on the performance of a microbial fuel cell employing ceramic separator

Microbial fuel cell (MFC) provides a one-stop solution to wastewater treatment and depletion of existing energy resources. One of the major performance limitations of MFC is pH splitting that results in decreased pH of the anolyte affecting the growth of anaerobes. Hence an attempt was made in this study, to provide a suitable pH-controlled environment for microorganisms by recirculating the wastewater fed to the anode chamber. Four MFCs were fabricated allowing anolyte recirculation with different anolyte pH, viz, MFC-1 (pH 5, R.R. 1:2), MFC-2 (pH 5, R.R. 0), MFC-3 (pH 9, R.R. 1:2) and MFC-4 (pH 9, R.R. 0), where R.R. is recirculation ratio. MFC-3 and MFC-4 showed higher power generation and organics removal in comparison to MFC-1 and MFC-2. Anolyte recirculation in combination with alkaline pH improved the overall performance of the MFCs because of better substrate availability and suitable growth conditions provided to the microorganisms.

Automated summary

Recirculating wastewater to the anode chamber with proper pH control improved the performance of microbial fuel cells, leading to higher power generation and better organics removal due to enhanced substrate availability and growth conditions for microorganisms.