Industrial wastewater treatment with simultaneous energy recovery using microbial fuel cells - A review

The dual benefit of microbial fuel cells (MFC) for wastewater treatment with simultaneous power generation opens new perspectives and possibilities for industrial wastewater treatment. At present, research focuses on municipal wastewater instead of industrial wastewater treatment, which may be more attractive due to savings in discharge fees, if the required treatment efficiency can be achieved. Accordingly, the objective of this literature review is to clarify whether MFCs can be used for industrial wastewater and whether they are currently competitive with conventional anaerobic-aerobic wastewater treatment plants. Therefore, an overview of MFCs treating industrial wastewater (e.g. breweries, dairy, paper) on a laboratory or pilot scale will enable an assessment of possible applications. Self-sufficient wastewater treatment and further nutrient removal (nitrogen, phosphorus, etc.) will be of additional interest due to possible energy recovery and the tightened discharge limits. The assessment of MFCs with regard to conventional anaerobic or aerobic treatment was pointed out, and combination possibilities were explored. The feasibility of MFCs for the treatment of industrial wastewater and their possible self-sufficient treatment has been demonstrated by several laboratory and pilot scale studies. MFCs can treat both low and high chemical oxygen demand (COD) concentrations, but do not require aeration as in aerobic treatment and, unlike anaerobic treatment, can be operated on a small scale. In addition, the removal of nitrogen, total suspended solids (TSS) and sulphates is possible with MFCs, only the removal of phosphorus is not expected. The modularity and the wide range of operation are the main advantages of MFCs, making MFCs an alternative or complement to conventional industrial wastewater treatment.