Adsorption Behavior and Influencing Factors of Sulfamethoxazole and Carbamazepine on Porous Media

This study results show that the adsorption processes of SMX and CBZ by pore media follow Lagergren model and Langmuir model. The adsorption process can be characterized by rapid adsorption and slow equilibrium and it is a monomolecular layer chemical adsorption. The adsorption of SMX is a spontaneous exothermic process, while the adsorption of CBZ is an endothermic process. Under the experimental conditions, the maximum adsorption capacity of SMX and CBZ of silt with small particle size, high organic matter content and large specific surface area is 3.0 times and 2.3 times of that of fine sand, respectively. The adsorption of SMX is mainly affected by the electrostatic attraction of mineral surface and the distribution of organic matter, while CBZ is more controlled by the distribution. The adsorption capacity of SMX in silt that existed mainly in anionic form increases with the increase of pH value (5.0～9.0), while the adsorption capacity of CBZ in molecular form does not change significantly with the change of pH. The coexistence of dissolved humic acid (8～50mg/L) inhibits the adsorption of SMX and CBZ. The adsorption capacity of SMX and CBZ increases with the increase of organic matter and iron oxide content in porous media. The BRIEF REPORT is available for this paper at http://www.ykcs.ac.cn/en/article/doi/10.15898/j.ykcs.202407110154.