Removal of polyvinyl alcohol from aqueous solutions using P-25 TiO₂ and ZnO photocataysts: A comparative study

This investigation evaluates the effectiveness of P-25 TiO₂ and ZnO in removing polyvinyl alcohol (PVA) from aqueous solutions. The effects of pH, photocatalyst dosage, initial PVA concentration, and UV wavelength on the removal efficiency of PVA were studied. Under acidic conditions, the removal efficiency of PVA using P-25 TiO₂ exceeded that under alkaline conditions. However, the removal efficiency of PVA using ZnO under alkaline conditions exceeded that under acidic conditions. Additionally, the removal efficiency of PVA increased with photocatalyst dosage, but declined as the initial PVA concentration increased. The UV wavelength slightly affected the removal efficiency of PVA using P-25 TiO₂, but dramatically affected that using ZnO. At UV-254nm, pH9, a photocatalyst dosage of 0.12g/L, and an initial PVA concentration of 20mg/L, the removal efficiencies of PVA using P-25 TiO₂ and ZnO were 54% and 74%, respectively. Therefore, at UV-254nm and pH9, ZnO was more effective than P-25 TiO₂.