Application of TiO2/ZnFe2O4/glycine nanocatalyst to the treatment of methyl orange dye from aqueous solution: Impacts of dissolved mineral salts on dye removal efficiency

This study aimed to remove one of the frequently used dyes in textile industries, Methyl Orange, from pollutant water with TiO2/ZnFe2O4/Glycine nanocatalyst under UV irradiation. The TiO2/Glycine/ZnFe2O4 nanocatalyst was synthesized through the sol-gel method and characterized by XRD, XRF, FT-IR, UV-Visible DRS, BET, FE-SEM, and EDX analyses. Process factors, including initial dye concentration (10-30 ppm), nanocatalyst dosage (0.5-1.5 g/L), initial pH solution (3-11), and irradiation time (30-150 min), were investigated by central composite design. The removal efficiency of Methyl Orange was 80% under optimal conditions (dye concentration: 20 ppm, nanocatalyst dosage: 1 g/L, irradiation time: 120 min, and pH=6.5). The effects of mineral salts such as NaHCO3, NaCl, Na2SO4, KCl, MgSO4, and CaCl2 with the concentrations of 50-800 ppm on the dye removal efficiency were examined under the optimal conditions. Low concentrations of NaCl, KCl, and CaCl2 had adverse effects on MO removal efficiency, while the dye removal efficiency raised at their high levels (RNaCl.800=74.52%). An increase in concentrations of MgSO4 and Na2SO4 led to deactivation effects on the dye removal efficiency and reaction rate constant (MgSO4 deactivation: 36%). There was an upward trend in the pollutant removal efficiency and reaction rate constant using NaHCO3 (RNaHCO3.800=82.4% and kNaHCO3.800=20.84 day-1).