Effective removal of humic acid using strontium-doped TiO2 coated on porous ceramic filter media in water resource

Abstract

A photocatalyst comprised of strontium-doped TiO2 coated on porous ceramic filter media (Sr-TiO2/PCFM) was prepared using the heat-treated process. The main objective of this study was to investigate the effects of catalyst dosage, initial HA concentrations, pH, and temperature on the adsorption and degradation of humic acid (HA) in a solution containing Sr-TiO2/PCFM under irradiation of UV light. Removal efficiency of 84.25% for HA was achieved under experimental conditions for a Sr-TiO2/PCFM dosage of 80 g at an initial concentration of 15 mg/L over a period of 8 h. Higher degradation was found for HA in the acidic environment and at higher operating temperatures. The rate of the adsorption reaction followed the pseudo second-order kinetics with the sorption isotherm well fitted to the Freundlich and Langmuir isotherm models. The oxidation rate constants of HA were evaluated by using pseudo first-order kinetics that can describe the photodegradation process. Furthermore, the photocatalytic stability of Sr-TiO2/PCFM was performed with 3 cycles reused. These findings suggest that the Sr-TiO2/PCFM was found to be an effective and promising approach to eliminating HA in water resources.