Palm oil mill effluent treatment using tungsten trioxide: Adsorption and photocatalytic degradation

Today, some of the major disadvantages of conventional palm oil mill effluent (POME) treatment are that the process is time consuming, as well as space consuming. Besides, most of the recent photocatalyst still have a limitation that able to demonstrate their good performances only under sources of light. The visible-light-driven energy storage photocatalyst, which is tungsten trioxide (WO3), has been developed to overcome the limitations mentioned. Therefore, the present study aims to investigate the comparative calcination temperature and the degradation of POME using WO3 as a photocatalyst in adsorption and photocatalytic processes under visible light irradiation. An eco-friendly WO3 photocatalyst was synthesized by coprecipitation method. Subsequently, the resulting WO3 was characterized by Fourier-transform infrared spectroscopy (FTIR) to evaluate the significance of calcination temperature towards WO3. Furthermore, the adsorption activity of WO3 towards POME was investigated at different sources of ponds (cooling, anaerobic and aeration) throughout 300 min. This study reports on the efficiency of adsorption activity of WO3-400 °C towards pond aeration pollution, which showed that it was better than that in anaerobic and cooling ponds based on the chosen study criteria of color and suspended solid removal for the investigation of photocatalytic activity. Moreover, WO3 was proven to be able to conserve energy, where it was demonstrated that POME can still degrade consistently in darkness, with the highest color removal of approximately 48% was obtained. An extraordinary photocatalytic treatment with WO3 functioning simultaneously as the light harvesting and energy storage material is deemed as an efficient photocatalyst for POME in terms of decolorization and removal of suspended solid.