ACCELERATION OF SOLID WASTE BIODEGRADATION IN TROPICAL LANDFILL USING BIOREACTOR LANDFILL CONCEPT

Recently, a process based approach in landfill design and operation has been developed called bioreactor landfill. A bioreactor landfill is managed to accelerate decomposition of the organic wastes by controlling moisture content, recycling nutrients and seeding of microorganisms by circulating leachate back into the landfill cell. This research investigated the beneficial effect of using this concept in accelerating the biodegradation of wastes and simultaneously minimizes leachate problem in tropical landfill. The study was conducted in laboratory and pilot scale experiments. The laboratory scale experiment was conducted using 70 liter digesters over 245 days having different leachate circulation of 4,8 and 15 times per month suggested that landfill cell with leachate circulation of 15 and 8 times per month yielded higher methane production than that of 4 times per month. The digester with 8 times per month of leachate circulation has reached methanogenic phase after 104 days. In pilot scale experiment, four landfill lysimeters of 0.9 m. and 2.7 m. height were employed. The biodegradation of solid wastes in the lysimeters having different operating techniques, i.e. leachate circulation and leachate storage in the waste cells was compared with the conventional landfill operation. It was found that those operating techniques were beneficial to waste degradation and leachate management in tropical landfill. The water balance in those lysimeters was also verified