Potential application of landfill leachate as the substrate for electricity generation.

Environmental pollution by wastewater is a prominent crisis in the modern world, and currently, available treatments consume high amounts of electricity, leading to another global crisis of resources. Present system designs in Malaysia focus mainly on treating municipal effluents. This leaves a wide scope for treating other substrates such as landfill leachate effluents. Landfill leachate is one of the alarming pollutants of water reservoirs due to the presence of high concentrations of contaminants such as chemical oxygen demand, ammonia, phosphate, nitrogen, and harmful heavy metals. This raises an immediate focus to modernize its' treatment system in Malaysia by using sustainable biological treatment with minimal use of energy. Thus, this research targets treating leachate landfill wastewater using an anaerobic digestion process by bacteria that will not only remove the high chemical oxygen demand contents of the wastewater but also utilize them to generate electricity. The two anaerobic electrogenic bacteria, Shewanella oneidensis and Klebsiella pneumoniae were used in this study at 10%, 30%, and 50% concentration, presenting a substantial removal of chemical oxygen demand (COD) from landfill leachate wastewater, in turn, producing a power output of 0.09μA to 0.36μA on a microliter scale, measured using a compact paper-based electro-fluidic array that mimics a microbial fuel cell. However, the bacterial digestion of landfill leachate was found to be inhibited due to the presence of high concentrations of ammoniacal nitrogen and phosphate.