Palm oil mill effluent (POME) has high soluble and insoluble organic materials, which contribute to its high Biological Oxygen Demand (BOD) content, thus, posing a challenge in treating it. More challenges are anticipated if the limit of BOD level below 20 ppm were to be imposed by the Department of Environment. Currently, the industry is applying the conventional tertiary/ polishing treatment as an additional step after the secondary treatment (biological) to treat POME. However, most of the tertiary/polishing treatments fail to achieve the BOD 20 ppm consistently. This was due to high insoluble BOD content in POME contributed by suspended solids (SS) that are difficult to be degraded during the biological treatment. This problem can be tackled by introducing the combination of microand ultra-filtration technology to maximise the simultaneous removal of the SS and insoluble BOD from the POME. The integration of microscreen and membrane ultra-filtration system will reduce the insoluble BOD by removing both large and fine solids from digested POME. New filtration media, which is a stainless steel microscreen filter replaces the conventional clarifier system to enhance solid removal after the biological treatment. At this level, using the right type of chemical and dosage, the system is able to remove SS from the influent at a minimum of 80% and consequently reduce the BOD by 20%. Effluent from the micro-screen filter is further treated in the membrane ultra-filtration system to remove the remaining fine solids. This reduces the BOD and SS with a minimum of 90% removal.

Researcher: Nor Faizah Jalani