Treatment of landfill leachate at Padang Siding Perlis using microbial fuel cells and Fenton methods

Landfill leachate is generally known as high-strength wastewater that is highly difficult to handle and contains extracted dissolved matter and suspended matter. This study presents the removal of the leachate components such as chemical oxygen demand (COD), biochemical oxygen demand (BOD), total suspended solid, ammonia and colour using an integrated bio-electrochemical and Fenton method. The integration was carried out so that the two methods could complement each other. Microbial fuel cells (MFCs) were designed to treat landfill leachate while continuously producing power (voltage output). Three anodes were tested in the MFC reactor: black carbon, activated carbon, and zinc electrodes. Movements in the MFC reactor during treatment were a key factor for testing. Thus, the system was operated in different modes: static and dynamic. Both modes showed a difference in the ammonia level of the three anodes used. This study compared the static and dynamic modes of the MFC in removing ammonia. The continuous reactor movement could increase the rate of ammonia component removal. The reactor also provided a viable condition for maximum removal. The reactor movement caused the sludge to disintegrate and enabled the ammonia to separate easily from the parent leachate. Ammonia removal also resulted from the transfer of ammonium through the salt bridge or from ammonia loss. The constant exchange of ionic content benefited the MFC performance by increasing power production and decreasing internal electrode material resistance. This paper presents the results of leachate treatment analysis from the solid waste landfill located in Padang Siding Landfill, Perlis. Ammonia removal was enhanced using different types of electrodes. In both modes, activated carbon provided better performance than black carbon and zinc. The percentages of leachate components removal for activated carbon zinc and black carbon with dynamic mode was generally higher over static mode. The final values of the ammonia, COD, BOD, TSS and colour were 13 mg/L (97.66% removal), 490 mg/L (86.10% removal), 249mg/L (77.98% removal) and 106mg/L (42.20% removal) respectively. The leachate samples were further treated with Fenton in order to reduce the level of the components. For Fenton process, the effect of influential parameter were verified by statistics approach, 17 experiments were run based on RSM generated DOE. The experimental results were fully complied with predicted results from the RSM. The optimal conditions in term of FeSO4 and H2O2 concentrations and pH for ammonia, COD, BOD, TSS and Color removal are pH (3.94), FeSO4 (19.68 mg/L) and H2O2 (40.39 mg/L). The removal efficiencies of ammonia, COD, BOD, TSS and Color are approximately ~16.92%, 78.72%, 88.35 %, 75.91% and 88.16% respectively.