Solid waste landfill leachate treatment from garbage truck using immobilized white rot fungi

In recent years, solid waste management and disposal has become one of the most important environmental concerns. Landfill technology is widely used for disposal. of waste but it results in generation of leachate. This leachate constitutes a major environmental problem as it is highly polluted due to the presence of several contaminants such as organic matter, color, heavy metals and suspended solids. Treatment method for leachate depends on chemical composition of leachate and age of landfill. Several physico-chemical methods could be used for leachate treatment but most of them are costly. Biological methods offer a cheap solution for treatment of landfill leachate. White rot fungi produces various isoforms of extracellular oxidases including laccase, Manganese peroxidase and lignin peroxidase to degrade the pollutants. In this research, decolorization of fresh leachate from garbage truck in Nonthaburi, Thailand by white rot fungi, Trametes versicolor and Flavodon flavus was studied. The fungi were immobilized on polyurethane foam. Glucose, corn starch and cassava were investigated as a co-substrate. Treatment efficiencies were evaluated based on color, BOD and COD. The optimum pH was found to be 4. The optimum co-substrates concentration for glucose, corn starch and cassava was found to be 3 g/L, and the optimum contact time to be 10 days for both fungi. Among three types of co-substrates, glucose showed the best color removal. Results obtained by T.versicolor were better than F.flavus. Maximum decolorization of 78.79 and 73.20% could be achieved for T.versicolor and F.flavus, respectively with 3 g/L of glucose. Fungi can not only reduce color but also BOD and COD. BOD removal of 65.42% and COD of 53.28% for T.versicolor, and BOD and COD removal for F.flavus was 60.76% and 56.33%, respectively. Because of their unique properties in biodegradation, white rot fungi can be considered as potentially useful microorganisms in landfill leachate treatment.