Dispersion induced ozone pretreatment of waste activated biosolids: Arriving biomethanation modelling parameters, energetic and cost assessment

In this study, the phase separated effect of dispersion induced ozone pretreatment (DOP) was investigated. Solid reduction, biomass lysis and biomethane production were used as essential parameters to assess the potential of DOP over ozone pretreatment (OP). A higher suspended solid reduction of about 25.2% was achieved in DOP than OP 18%. The ozone dosage of 0.014 gO(3)/g SS supported a maximal biomass lysis of about 32.8% when the biosolids were subjected to prior dispersion at 30 s and 3000 rpm. However, the same ozone dosage without phase separation achieved 9.6% biomass lysis. The second exponential model results of the biomethane assay showed that DOP enhanced the accessibility of disintegrated biosolids for methane production and induced about 1150 mL/g VS of methane production. The energy analysis reveals that DOP provides significant amount of positive net energy (152.65 kWh/ton) when compared to OP (-12.42 kWh/ton).