ABSTRACT
Palm oil mill secondary effluent contains an extremely high amount of degradable organic substances which may act as substrates for microorganisms in the waterbody and at the same time impede the light source from reaching the photosynthetic organisms. Compared to several conventional effluent treatment systems adopted by palm oil millers, a nanofiltration membrane photocatalytic reactor (MPR) can be considered as one of the promising methods due to its advantages. MPR enables the operation with high amounts of the catalyst due to the presence of membrane, and provides the advantage of molecule residence time control during the process, simple configuration, effective use of light source with a photocatalyst, and high possibility of reusing photocatalyst for subsequent experimental runs. For in-depth exploration, zinc oxide (ZnO) has been claimed as the most suitable catalyst to be used in MPR due to its high reactivity, surface area, chemical stability, photosensitivity, non-toxic nature, and low cost.
