BACKGROUND: The present work explores the catalytic and electric performance of a microbial fuel cell (MFC) implemented with high chemical oxygen demand (COD) industrial wastewater from Spain. The polymer inclusion membrane based on 70% [MTOA][Cl] IL was used as separator and showed a good efficiency in power production and COD removal. RESULTS: Outputs of 72% in COD conversion, 200mV voltage and 32mWm(-3) power density were obtained, demonstrating that slaughterhouse wastewater is a good feedstock for the scale-up of this technology. Furthermore, the effect of the microbial fuel cell on the physical/chemical parameters of the slaughterhouse wastewater was analyzed. The concentration of nitrite, orthophosphate, sulfate and ammonium was reduced by more than half. CONCLUSIONS: Air breathing cathode-microbial fuel cells based on polymer ionic liquids inclusion membranes allow the treatment of an industrial and high load slaughterhouse wastewater with good depuration and electrical performance efficiency. (c) 2016 Society of Chemical Industry