The purpose of this study is to determine the impact of leachate recirculation on stabilisation of municipal solid wastes. The study was carried out by using two labscale landfill bioreactors containing approximately 10 kg of waste each, in order to follow waste degradation over 16 weeks of time period. The main difference between anaerobic recirculated and without recirculation bioreactors options is determined in leachate quality. Leachate quality is regularly measured by the means of pH, electrical conductivity, calcium, magnesium, total kjeldahl nitrogen, phosphate and chemical oxygen demand (COD). It has been observed that leachate recirculation is more effective on anaerobic degradation of solid waste than nonrecirculated degradation. The leachate recirculated bioreactor appears to be the more effective option in the removal of COD by 89.93% and stabilisation of pH at 7.5. After 16 weeks of anaerobic degradation, waste stabilization seemed to have reached for the recirculated bioreactor. Therefore, further studies required to determine the optimum operational conditions for leachate recirculation rates, also with the operational costs of recirculation for solid waste stabilisation.
Municipal solid waste, leachate, leachate recirculation, landfill bioreactor, cow dung
