ABSTRACT
Palm Oil Mill Effluent (POME) is a thick suspension that contains high strength of Chemical Oxygen Demand (COD) of 48,000 mg/L, and Biochemical Oxygen Demand (BOD5) of 22,000 mg/L. In the present study, effects of low frequency ultrasound on solids solubilization in POME were investigated. Different ultrasonic densities (1.0–3.5 W/mL) were applied for 10 s. The Soluble COD (SCOD)/Total COD (TCOD) ratio and biodegradability of soluble organic matter increased after sonication; indicating an increase in disintegration in POME. The maximum SCOD/TCOD ratio reached almost 50% while particle size reduced by 25% for sample sonicated at 1.25 W/mL for 10 s. The BOD5/SCOD ratio also increased after sonication suggesting the biodegradability of the soluble organic material increased during the treatment. While sonication density exhibited the most significant role in cavitation bubble behavious, particle disruption could be optimized for energy input by sonicating at the optimum sonication density range.
