Characteristics and performance of biofilms on the electrode of bioelectrical systems within industrial wastewater in fisheries

Abstract

Abstract Microbial fuel cell (MFC) is a bioreactor which utilizes exoelectrogenic bacteria as electrocatalysis to convert bioenergy from biochemical substances into electrical energy. This research aimed to determine the formation of biofilms attached, the electrical voltage generated from MFC and its effect to reduce biological oxygen demand (BOD), chemical oxygen demand (COD), total ammonia nitrogen (TAN), and to determine the characteristics of the microbes formed. The MFC system has a single chamber using boiled fish processing wastewater as media. Microbial density within the biofilm attached to anode and cathode of the MFC showed different microbial counts. There was quite high density on the cathode but no microbial growth on the anode, either by Nutrient Agar (NA) or deMan-Rogosa Sharpe agar (MRSA) media in plating method. The electricity produced was 0.39 V on average, the highest value was 0.49 V at 42 hours. The MFC system was able to decrease the average value of 83.0% BOD and 83.5% COD. The TAN value increased from 0.063±0.01 to 0.36±0.16 mg/L. There were 12 bacterial isolates, six grown on NA and others on MRSA. Three isolates that grew on NA had different characteristic groups of colony and six on MRSA showed six different characteristics.