Performance evaluation of bioreactor landfills with leachate recirculation: an experimental study

The present study analyses the effect of leachate recirculation on fresh municipal solid waste transformation. Investigation of bioreactor landfills is the need of the hour in developing countries like India, with rapid population growth. The leachate recirculation method was adopted to assess the improvement in leachate and methane generation characteristics in biogas under anaerobic conditions. Fresh municipal solid waste was filled in small-scale bioreactor simulators. The anaerobic conditions were maintained, keeping the simulators airtight. Leachate recirculation was once a week. Biochemical characteristics of leachate and methane produced were analyzed once a week. The duration of the study was 104 days. The total quantity of gas was 11.17 liters and was validated through the Gompertz equation. Methane percentage varied in the range of 10–25%. A reduction in organic content indicated active microbial digestion. Elemental analysis indicated a 22.83% reduction in carbon at the end. The reduction in leachate characteristics showed a decrease in its pollution strength. It was found that leachate recirculation in bioreactor landfills accelerates biogas generation and serves as leachate treatment. Experimental results showed improved leachate quality upon recirculation in a bioreactor simulator.