Upgrading the biogas production from raw landfill leachate using O3/H2O2 pretreatment process: Modeling, optimization and anaerobic digestion performance

Here, a combined pretreatment oxidation process (O-3/H2O2) was investigated to enhance the biodegradability of raw landfill leachate (RLL) and biomethane potential (BMP) in anaerobic reactors. The central composite design (CCD) and response surface methodology (RSM) were employed to optimize the operational parameters influencing on RLL bioavailability in O-3/H2O2 process: pH, Oxygen Flow rate, Reaction Time, and H2O2 concentration. The findings revealed that the O-3/H2O2 increased biodegradability index (BOD5/COD) of RLL from 0.41 to 0.68 under optimized condition (pH=8, Oxygen flow= 0.25 L.min(-1), Reaction Time= 25 min, H2O2 concentration= 2.5 g.L-1). Furthermore, the effects of O-3/H2O2 process on BMP of RLL were surveyed under mesophilic anaerobic reactors (Temperature: 37 +/- 1 degrees C) in viewpoints of operational performance and methane yield in a batch mode for incubation period of 24 days. The results showed that O-3/H2O2 process simultaneously improve the BMP by 2.99 times higher in a shorter lag-phase period (5 days) compared with control. The pretreatment O-3/H2O2 and mesophilic anaerobic digestion process revealed a feasible and efficient method for enhance BMP of RLL.