Performance evaluation of a landfill leachate recirculation treatment system using quadric model

Aim: The present research was carried out to study the effects of recirculation of leachate in cylindrical shaped anaerobic bioreactor on treatment of leachate as well as stabilization of municipal solid waste. Quadric and regression model were used to study the behavior of operating parameters over time scale and on COD, respectively. Methodology: 19 kg of solid waste was filled and compacted and in reactor and water was added to it till 20 liters of leachate prepared. The whole unit was sealed air tight and leachate was recirculated @ 28 ml/min for 12 hours daily. Physico-chemical characterization of leachate and and solid waste was done by using standards methods of analysis. Results: Results shows that the parameters like pH (6.69 to 7.74), alkalinity (7100 to 1600 mg l(-1)), VFA alkalinity ratio (1.44 to 0.33) etc. were within the optimum range of anaerobic degradation. COD is an indicator of organic contamination and a reduction in 96% COD was observed at the end of 29 weeks of leachate recirculation. The quadric model also confirms that the most of organic and inorganic contaminants of leachate were decreased and alkalinity was increased with time. In addition to leachate treatment, a reduction of 26.3% volume of MSW was observed after completion of study. Interpretation: The performance of Leachate Recirculation Bioreactor was excellent as most of organic and inorganic contaminants were decreased and pH and alkalinity were increased with time. Thus, this technology can be a good solution of MSW problems of countries like India which demands urgent attention in this direction as it treats the leachate as well as stabilize the solid waste. [GRAPHICS] .