Palm oil mill effluent treatment - Liquid-solid separation with dissolved air flotation

Abstract

This is a second report on the treatment of palm oil mill effluent (POME) using liquid-solid separation, following experimental research studies conducted at the Environmental Engineering Laboratory, National University of Singapore. A laboratory-scale dissolved air flotation (DAF) unit was constructed and used to assist liquid-solid separation in POME treatment. DAF operating parameters: pressure vessel efficiency, total suspended solids loading rate, surface loading rate, air/suspended solids ratio and flocculation requirements were investigated. Compared to its solubility in potable water, air's solubility in treated POME, used as recycle water for the pressure vessel, was markedly lowere. Higher pressures had to be used to increase the input of air. This, fortunately, also resulted in smaller air bubbles which improved liquid-solid separation.