The effect of advanced oxidation processes on leachate biodegradation in recycling lysimeters.

Landfill processes were simulated in laboratory-scale bioreactors--lysimeters. The changes in leachate characteristics as well as the influence of advanced oxidation processes (AOPs) on the processes taking place in the sanitary landfill were investigated. Lysimeters were filled with material simulating municipal waste in the city of Lodz, Poland. Compost in the amount of 30% w/w and the methanogens inoculum were added in order to enhance development of a methanogenic phase. The leachate produced in lysimeters was recirculated. In order to investigate the influence of AOPs implementation on processes taking place in landfills two runs in lysimeters were performed, each lasting about 250 days. The leachate composition and biogas composition and production changes showed trends that confirmed that the bench-scale lysimeters appeared suitable to simulate processes taking place in the landfill. The application of AOPs to the leachate recirculated into the lysimeters did not bring about unequivocally positive effects. The ozonation of the leachate, implemented at the beginning of the methanogenic phase, caused slight acceleration (about 2 weeks) of the biodegradation, whereas employment of H2O2/UV led to the inhibition of anaerobic processes.