Atenolol removal from aqueous solutions using Bi2O3/TiO2 under UV-C and visible light irradiations

Abstract

ABSTRACT In this study, Bi2O3/TiO2 composite was successfully synthesised using the solvothermal method, and the morphology, composition, and surface area of the composite were determined. Comparisons of photocatalytic performance were performed using Bi2O3/TiO2 for the decomposition of Atenolol (ATN) a β-blockers that is generally used to treat disorders such as hypertension and arrhythmias, as a model contaminant under visible light irradiation. The effects of different parameters such as solution pH, catalyst dosage, initial ATN concentration, reaction time, coexisting cations and anions, and turbidity on the degradation efficiency of ATN were investigated. An excellent synergistic effect was observed in the decomposition of ATN with the simultaneous application of Bi2O3/TiO2 and LED compared to single processes (synergistic index value, 4.027). The Bi2O3 catalyst has a much lower photocatalytic performance for the decomposition of ATN than the synthesised Bi2O3/TiO2 composite. The optimal rate for pH, catalyst dosage, and initial concentration of ATN was 7, 400 mg/l and 10 mg/l, respectively. Under optimal conditions, about 68.92% and 22.58% of ATN were degraded after 60 minutes in the presence of Bi2O3/TiO2 and Bi2O3 catalysts, respectively. However, these efficiencies are reduced to 51.83% and 12.4%, respectively, under 50 NTU. The addition of co-existing anions, especially PO4 3 ⁻, remarkably reduced the efficiency of ATN removal in the Bi2O3/TiO2/LED process. The presence of cations promoted the degradation of ATN in the Bi2O3/LED process, while the efficiency of ATN degradation was inhibited by the presence of cations in the Bi2O3/TiO2/LED process. The ATN removal efficiency using LED irradiation (49.02%) was much higher than that of UV-C irradiation (27.16%) when the concentration of ATN was 30 mg/L.