Application of Cavitation Ozonation Process on Recalcitrant Organic Matter Degradation from Stabilized Landfill Leachate

Treatment of stabilized leachate as a by-product of municipal landfills has been a significant challenge as the leachate contains recalcitrant organic matter which has low biodegradability. In this study, the efficacy of the advanced oxidation process using cavitation–ozonation to remove recalcitrant organic matter in leachate samples from TPST Bantar Gebang was evaluated. Several operational and process parameters including pH, ozone flowrate, and contact time were varied to determine the best conditions for removing recalcitrant organic matter represented by Chemical Oxygen Demand (COD). This study determined the optimum operating conditions for the cavitation–ozonation process: pH 11, ozone discharge of 3 L/min, and contact time of 30 minutes. The result was a COD removal efficiency of 20.37%, an increase of 52.06% in the concentration of BOD5, and a 90% increase in the ratio of BOD5 to COD. This study has shown that cavitation–ozonation is an effective pre-treatment, as it increases the biodegradability of stabilized leachate and reduces the load on subsequent treatment processes.