Photocatalytic degradation of industrial dye wastewater in presence of ZnO-PEG nanoparticles

Abstract

Dye wastewater is one of the very dangerous pollution sources that can harm millions of human lives and caused critical effect to the eco-system. One of the beneficial methods for treating dye wastewater is photocatalysis process due to its quick oxidation of pollutants up to the parts per billion (ppb) level and it is proved that this process does not produce any polycyclic product. Zinc oxide (ZnO) has been claimed as the excellent photocatalyst in photocatalytic degradation process of dyes because of its high photo sensitivity, chemical stability and broad range of radiation absorption. However, agglomeration in the synthesis of ZnO is a serious problem because photocatalytic activity of ZnO is influenced by particle size, shape and surface morphology. Therefore, polyethylene glycol (PEG) is needed to control the shape and particle size of ZnO since it revealed the maximum coagulation concentration and critical stabilization concentration in the stabilizing process of the gold nanoparticles. From the studies, the optimum loading of PEG in precipitation of ZnO nanoparticles had successfully assess by comparing the effectiveness of all type of ZnO-PEG (0.015, 0.020 and 0.025 g/L of PEG) in photocatalytic degradation of dye wastewater. Hence, 0.015 g/L PEG loading in ZnO nanoparticles has the most optimum of PEG loading due to the highest degradation percentage of dye removal which is 95.48%. pH 7 was observed to be the optimum condition since it revealed the highest dye degradation percentage which is 95.48%. Hence, it can be concluded that with the presence of ZnO-PEG nanoparticles as a photocatalyst could greatly remove the dye particles in wastewater.