In-Situ Leachate Management in a Tropical Landfill by Storage and Recirculation Operation Techniques

This paper presents the application of storage and recirculation techniques to leachate management in tropical climate. Four pilot-scale landfill lysimeters were operated under different operational mode, i.e. 1) conventional landfill operation (control) 2) leachate re-circulation 3) internal storage with recirculation and 4) internal storage without recirculation. The experiment was carried out to quantify the amount and characteristics of leachate produced from landfill lysimeters operated in tropical climatic rainfall event. Variation in leachate characteristics, methane content in landfill gas was studied. The study revealed that leachate re-circulation and storage operation yielded lower organic concentration in leachate and highest methane content in landfill gas. Leachate re-circulation practice enhanced degree of waste stabilization. Rainfall intensity and leachate re-circulation practice affected leachate quantity as well as organic and nitrogen leaching from wastes. Partially degraded wastes in landfill lysimeters was further stabilized by in-situ aeration method. The aeration helped reducing stabilizing nitrogen in wastes. Leachate recirculation with aeration could produce leachate with its characteristics similar to those of matured leachate. The stabilized waste matrix was then successfully applied to the treatment of fresh leachate under aerobic condition