Eco-friendly bio-electro-degradation of textile dyes wastewater

The concept of bio-energy production in microbial fuel cells (MFCs) utilizing many types of domestic and industrial wastewater has already been established. However, biodegradation of wastewater with the additional benefit of bioenergy generation from the azo dyes contaminated wastewater from textile industry specifically and in particular, the efficiency of hybrid MFCs in this perspective has not been discussed so far. In this review, the performance factors affecting bioenergy generation in simple and hybrid MFCs treating the azo dyes during the electrochemical reaction are discussed. Various reactor configurations, mechanisms of dye degradation, the synergistic effect of hybrid systems, and decolorization studies with varied dye concentrations and inoculum sources are evaluated. Comparisons of treatment efficiencies suggest hybrid systems like constructed wetlands (CWs) can treat large volumes of wastewater and are more ecofriendly while the chemical pre-treatment of wastewater before biotreatment can perform 30–32% better in terms of dye removal as compared to simple MFCs. [Display omitted] •Bio-electro-degradation and power generation from azo dyes are possible in the MFCs.•Hybrid MFC systems have better degradation and dye mineralization rates.•Biofilm thickness and type of microbial species have critical role in degrading dyes.•Co-substrate can enhance dye degradation but organic loading decreases power generation.