Evaluation of Reactivity and Inhibitions in Developing Municipal Solid Waste Landfill Bioreactors for Tropical Climatic Conditions

Abstract

Landfill bioreactor concept is one of the novel technologies to satisfy the emergent power requirement of the world while minimizing the burden on the environment from municipal solid waste (MSW). However, performance evaluations of landfill bioreactors (LBR) studies in terms of defining failure in tropics were few. Three stages of researches in series were carried out for overcoming the shortcomings. In stage-1, a concrete lysimeter simulating a control landfill with diameter 1.3 m and height 3.32m was constructed and filled with 2727.9 kg of MSW. Stage-2 LBR-1 was constructed with a lower height 1.8 m and loaded with 1149.6 kg of MSW to identify the leachate recirculation effects to accelerate biological activity. Stage-2 LBR-2 was constructed with similar dimensions in stage-1 control landfill and 2052.7 kg of MSW was applied to enhance gas production and identify onset of inhibitions and toxicity. Finally, stage-3 LBR “test cell” was constructed with an extent of 8.3×5.3 m 2 and 51,940 kg of MSW filed at a placement density of 756.3 kg/m 3 . Bottom liner plus capping was constructed using clay -polyethyleneclay composite layer to minimize the toxicity and outfit the conditions. Stage-1 control landfill study explains the effect of rainfall on leachate generation and biological degradation. Stage-2 LBR-1 explains effect of leachate re-circulation and inoculation of cow dung on biological processes. Nevertheless, in LBR-2 created inhibitions and toxicity which exceeded 50,000 mg L -1 Biochemical Oxygen Demand (BOD5) and 80,000 mg L -1 Chemical Oxygen Demand (COD). Finally, the LBR ‘test cell’ liner removed nitrate nitrogen 30.1±1.9 mg L -1 , ionic compounds in the system and achieved standard permeability while generating helpful renewable landfill gas. DOI: http://dx.doi.org/10.4038/tar.v21i4.3314 TAR 2010; 21(3): 378-390