Photocatalytic Degradation and Toxicity Analysis of Sulfamethoxazole using TiO₂/BC

Abstract

Sulfonamide antibiotics in the environment not only disrupt the ecological balance but can also enter the human or animal body in various forms and cause harm. Therefore, exploring efficient methods to degrade sulfonamide antibiotics is crucial. In this study, we prepared biochar (BC) using corn straw, and TiO2/BC was obtained by doping different proportions of TiO2 into biochar with varying carbonization temperatures using the sol–gel method. Next, we investigated the degradation of sulfamethoxazole (SMX) in solution using the generated TiO2/BC under ultraviolet irradiation and studied the effects of various experimental parameters, such as the type of composite material, composite material addition, solution pH, and initial antibiotic concentration on SMX degradation. Under an initial SMX concentration of 30 mg/L, the composite with the best photocatalytic degradation performance was TiO2/BC-5-300 (i.e., 5 mL of TiO2 doping; 300 °C calcination temperature), with an addition amount of 0.02 g and a solution pH of 3. The degradation efficiency increased from 22.3% to 89%, and the most significant degradation effect occurred during the initial stage of photocatalytic degradation. In the TiO2/BC-5-300 treated SMX solution, the average rhizome length of bean sprouts was significantly higher than that of the untreated SMX solution and slightly lower than that of the deionized aqueous solution (3.05 cm 2/BC in the treatment of antibiotic-contaminated wastewater.

Keywords

• biochar
• photocatalytic degradation
• sulfamethoxazole
• titanium dioxide