Performance of a single chamber microbial fuel cell at different organic loads and pH values using purified terephthalic acid wastewater

Background: Purified terephthalic acid (PTA) wastewater from a petrochemical complex was utilized as a fuel in the anode of a microbial fuel cell (MFC). Effects of two important parameters including different dilutions of the PTA wastewater and pH on the performance of the MFC were investigated. Methods: The MFC used was a membrane-less single chamber consisted of a stainless steel mesh as anode electrode and a carbon cloth as cathode electrode. Both power density and current density were calculated based on the projected surface area of the cathode electrode. Power density curve method was used to specify maximum power density and internal resistance of the MFC. Results: Using 10-times, 4-times and 2-times diluted wastewater as well as the raw wastewater resulted in the maximum power density of 10.5, 43.3, 55.5 and 65.6 mW m?2, respectively. The difference between the power densities at two successive concentrations of the wastewater was considerable in the ohmic resistance zone. It was also observed that voltage vs. initial wastewater concentration follows a Monod-type equation at a specific external resistance in the ohmic zone. MFC performance at three different pH values (5.5, 7.0 and 8.5) was evaluated. The power generated at pH 8.5 was higher for 40% and 66% than that for pH 7.0 and pH 5.4, respectively. Conclusions: The best performance of the examined MFC for industrial applications is achievable using the raw wastewater and under alkaline or neutralized condition.