Effect of low intensity sonic mediated fragmentation of anaerobic granules on biosurfactant secreting bacterial pretreatment: Energy and mass balance analysis

In this study, fragmentation of anaerobic granules (AG) was carried out by low intensity sonification (LIS) to release its extracellular polymeric substance (EPS). The experimental outcome of the study shows that 30 s treatment time and 60 W sonic power was effective for fragmentation of AG. The fragmented anaerobic granules were further subjected to pretreatment by biosurfactant secreting bacteria. Bacterial pretreatment achieves a maximum biogranules lysis of 20.3% and biosolids reduction of 17.1% for fragmented anaerobic granules bacterial pretreatment (FAG-BP). Whereas for bacterial pretreatment (BP) alone, it achieves 10.9% and 8.6% of biogranules lysis and biosolids reduction respectively. Exponential first order kinetic model of biomethane production data revealed greater biomethane production for FAG-BP (0.247 g COD/g COD) than BP (0.131 g COD/g COD). Cost analysis of FAG mediated bacterial pretreatment results in a net profit of 48.606 USD/Ton.