Bioremediation of Landfill Leachate Using Isolated Bacterial Strains

Abstract

Landfilling is one of the most common and widely accepted practices for the disposal of waste throughout the world. Leachate, a major drawback of landfilling, continues to be produced at vast rates and current treatment options are costly and often inadequate. The management of leachate is of economic and environmental importance, due to its potential to cause contamination to ground and surface water. This research focuses on treating leachate in a cost-effective manner through bioremediation. Microorganisms were isolated from landfill leachate (LFL) and screened to determine their ability to remediate a wide range of compounds found in leachate, such as ammonia, phosphate and nitrate. Selected isolates were identified as belonging to the phylum’s Firmicutes, Actinobacteria, and Proteobacteria, isolates were inoculated into soil contained in a fixed bed column system. The column system was optimised and used for the treatment of LFL over a 10-hour period. High percentage removal rates were achieved for ammonia (>90%) and removal nitrate and phosphate (>60%). Although EPA discharge limits were not achieved, bioremediation using selected microbial strains represents a cost effective treatment option when compared to conventional methods. Research is now required to further optimise this system to achieve discharge limits for all compounds tested.