Abstract
In the palm oil mill effluent (POME) discharged during the production process of palm oil, oil is contained in the emulsion state. Currently, the open ponding system (facultative/anaerobic lagoons) is being applied as the main treatment method for POME owing to low operating costs. However, the main disadvantages of this system are the requirement of large land area, long retention time, and low treated-water quality. In this study, we developed a novel oil-water separation technique involving the use of a combination of micro- and normal bubbles for POME in order to reduce the environmental load as well as recover/reuse the separated oil. With the combination of micro- and normal bubbles, normal bubbles can accelerate the up-flow rate of microbubbles, improving the oil-water separation efficiency. As a result, it was confirmed that the combination of micro- and normal bubbles could improve the efficiency of oil-water separation. It was also confirmed that the effectiveness of this combination for actual treatment of POME was demonstrated in Thailand. The efficiency of oil-water separation of actual POME treated by the combination of micro- and normal bubbles was increased about 40% compared with that when only microbubbles were applied.
