Effect of pH on biochar adsorption of norfloxacin and sulfamethoxazole

• Main Authors: ZHANG Ya-ru, ZHANG Ying, SHI Xiang-li, LIU Ying, LIU Xian-bin, LU Shao-yong, BI Bin, WAN Zheng-fen, YANG Yong
• Format: Article
• Language: zho
• Published: Agro-Environmental Protection Institute, Ministry of Agriculture 2020-07-01
• Series: Journal of Agricultural Resources and Environment
• Subjects: biochar, antibiotics, ph, adsorption kinetics, adsorption isotherms
• Online Access: http://www.aed.org.cn/nyzyyhjxb/html/2020/4/20200413.htm

To solve the problems of antibiotic removal and resource utilization of reed straw in water, the adsorption isotherms and kinetics of norfloxacin (NOR) and sulfamethoxazole (SMX) on reed straw biochar at different pH were investigated. The results showed that the adsorption of biochar was related to the existent morphology of NOR and SMX in different pH solutions. With increasing pH, the adsorption of NOR by biochar increased first and then decreased, with maximum adsorption capacity of 7.80 mg·g^-1. The adsorption capacity of biochar to SMX decreased gradually in the range of pH 1~3, increased gradually in the range of pH 3~5, and decreased gradually when pH was greater than 5. The adsorption kinetics of NOR and SMX on biochar was more in line with the quasi-second-order kinetics equation and the adsorption process was affected by both surface adsorption and intraparticle diffusion. Isothermal adsorption behavior was more consistent with the Langmuir isotherm model, and the adsorption process was dominated by monolayer adsorption. Differences in the pH of the solution will affect the adsorption of NOR and SMX on reed straw biochar, which provides data support for the rational application of biochar in adsorbing antibiotics in water.