Catalytic Reduction of Hazardous Acid Orange 10 Dye by BiVO4/TiO2 Nanocrystalline Heterojunction and Influence of Aeration, FeSO4, H2O2 and FeCl3 on Removal Efficiency: A Novel and Environmentally Friendly Process

Bismuth vanadate in combination with titanium dioxide were synthesized by hydrothermal method and its photocatalytic activity was investigated under visible light irradiation for acid orange 10 (AO10) dye removal. The 10% BiVO4/TiO2 showed the highest catalytic activity in comparison with 20, 30, 40 and 50% BiVO4/TiO2 ratios. The removal of AO10 azo dye in aqueous solutions was studied in laboratory-scale experiments using 25 removal processes and their removal efficiencieswere evaluated, separately. The results showed that the amount of de-colorization for each oxidation process is completely different. The order of the investigated processes in removing the dye after 90 min is as follows: LED < TiO2 < BiVO4 < 10% BT/without LED < BiVO4/ LED < 50% BT < 40% BT < 30% BT < 20% BT < UV/H2O2 < 10% BT < 5a-10 %BT < 5F-10 %BT < 10a-10 %BT < 50F-10 %BT < 20a-10 %BT < 10F-10 %BT < 20F-10 %BT < 20H-10 %BT < 40H-10 %BT < 50H-10 %BT < 20a-20F-10 %BT < 20a-20F-50H-10 %BT. Among the above processes, 20a-20F-50H-10 %BT had the best removal performance and can be suggested for using in real conditions. Coagulation/precipitation process was done using 5 mg/L of FeCl3 as post-treatment reaching efficiency of 100% in the studied system.