Silver oxide-zeolite for removal of an emerging contaminant by simultaneous adsorption-photocatalytic degradation under simulated sunlight irradiation

The existence of contaminants of emerging concern such as pharmaceuticals in the water sources become a growing concern matter because of their increased consumption, incomplete disposal, and potential impacts on living organisms. Accordingly, the removal of these bioactive compounds from the aqueous environment also becomes a vital issue and different treatment techniques have been investigated. The novelty of this work lies in the synthesis and implementation of silver oxide anchored on Y zeolite (Ag2O@Y Zeo) as an untried effective photocatalyst for the removal of emerging contaminants. Ranitidine (RANI) removal from aqueous solutions was investigated in this study by simultaneous adsorption-photodegradation induced via simulated sunlight irradiation in the presence of Ag2O@Y Zeo. Ag2O@Y Zeo was prepared by thermal treatment at 400 degrees C of Ag-form Y zeolite which was prepared by ion-exchange. The produced catalyst was characterized by X-ray diffraction, scanning electron microscopy, energy dispersive analysis by X-ray, Fourier transform infrared spectroscopy, nitrogen adsorption-desorption isotherms, UV-Vis diffuse reflection spectroscopy and photoluminescence spectroscopy. The simultaneous adsorption-photodegradation of RANI using Ag2O@Y Zeo was investigated at various conditions including a catalyst dose (5, 10, 30, 50, and 70 mg/ 100 mL), an initial RANI concentration (10, 20, 30, 40, and 50 mg/L), and a solution pH (3, 5, 9, and 11). According to the results, the RANI removal percentage was 97.51% obtained at Ag2O@Y Zeo dosage of 30 mg/100 mL, an initial RANI concentration of 40 mg/L, a solution pH of 7.4 and a time of 75 min. These results were attributed to the important role of the photogenerated holes and photogenerated electrons over the synthesized catalyst and their generation can be induced only in the presence of simulated sunlight. The photodegradation process of RANI by Ag2O@Y Zeo followed the pseudo-first-order kinetic model and O-2 degrees- was the main reactive species.