Fatma S. Alloush, Mohammad A. Hillal
The study aimed to develop a laboratory reactor to treat textile wastewater from dyeing factories in Hama City using visible light and a catalyst comprising titanium dioxide, bismuth vanadate, and activated carbon. It explored varying catalyst concentrations (500-200 mg/L) and found 1500 mg/L to be optimal for the highest dye removal. The study also assessed the impact of pH on dye removal, noting pH 6 as optimal. Light wavelength (400nm to 660nm) significantly affected dye removal, with 400nm visible light showing the best results. Sodium persulfate at 1000 mg/L achieved 99% dye removal. Additionally, 500mg/L of ferrous sulfate was optimal for chemical precipitation. TiO2/BiVO4/AC photocatalyst exhibited the highest dye degradation efficiency among the variants, attributed to the BiO-TiO2 p-n heterojunction. BiVO4 enhanced photocatalytic activity by facilitating electron transfer, shifting the absorption spectrum to the visible light, reducing the TiO2 band gap, and suppressing electron-hole recombination. Violet light proved most effective in dye degradation compared to other visible light sources. The study highlighted superior dye removal efficiency (99% within 180 min) when employing chemical precipitation, ion exchange, and photocatalytic degradation combined. Treated Textile wastewater can meet Syrian irrigation standards (Syrian standard specification No. 2580 of 2008).