Progress on the adsorption and degradation mechanism of sulfonamide antibiotics in water by carbonaceous materials

Antibiotics can effectively inhibit or kill bacteria and are widely used in the prevention and treatment of human and animal diseases. Due to their long half-life and difficult metabolism, most antibiotics are excreted with feces and urine, leading to increasing antibiotic contamination in the surrounding aquatic environment, and sulfonamide antibiotics are one of the most common antibiotics. The removal of sulfonamide antibiotics from water has gradually become a research hotspot with the enhancement of people’s awareness of environmental protection and the improvement of detection technology. This paper reviews the preparation methods of carbonaceous materials (graphene, carbon nanotubes, biochar) for the removal of sulfonamide antibiotics at the present stage, as well as their adsorption and degradation effects on the removal of sulfonamide antibiotics in water and analyzes their removal mechanisms. One-dimensional carbon nanotubes as well as two-dimensional graphene materials were found to have much higher adsorption capacity for sulfonamide antibiotics than that of multidimensional materials such as biochar, and the adsorption of sulfonamide antibiotics by all three carbonaceous materials involves the mechanisms of π-π electron donor-acceptor, hydrogen bonding, electrostatics, hydrophobicity, charge-assisted hydrogen bonding, and electron acceptor action. A summary overview of the mechanisms of activation of persulfate, peroxyacetic acid, hydrogen peroxide, and ozone by carbonaceous materials reveals that both free radical and non-free radical pathway mechanisms work together to remove sulfonamide antibiotics, but the non-free radical pathway dominates the removal mechanism. To promote the development and improvement of the basic theory of sulfonamide antibiotic removal by advanced oxidation technology, and to better serve the management of water ecosystems and the solution of environmental problems.

抗生素（antibiotics）可有效抑制或杀灭细菌，被广泛应用于人与动物疾病的预防与治疗。由于抗生素半衰期长、代谢难度大，大部分抗生素会随粪便与尿液排出体外，进而导致周边水环境中的抗生素污染日益加剧，而磺胺类抗生素（sulfonamide antibiotics）便是最常见的抗生素品类之一。随着人们环保意识的提升与检测技术的进步，水中磺胺类抗生素的去除研究逐渐成为科研热点。本文综述了现阶段用于去除水中磺胺类抗生素的碳质材料（carbonaceous materials）——石墨烯（graphene）、碳纳米管（carbon nanotubes）、生物炭（biochar）的制备方法，及其在去除水中磺胺类抗生素过程中的吸附与降解效能，并分析了其去除机制。研究发现，一维碳纳米管与二维石墨烯材料对磺胺类抗生素的吸附容量远高于生物炭等多维材料；且三种碳质材料对磺胺类抗生素的吸附均涉及π-π电子供体-受体作用、氢键作用、静电作用、疏水作用、电荷辅助氢键作用及电子受体作用等机制。本文还综述了碳质材料活化过硫酸盐（persulfate）、过氧乙酸（peroxyacetic acid）、过氧化氢（hydrogen peroxide）与臭氧（ozone）的作用机制，结果表明，自由基与非自由基两种途径机制共同参与磺胺类抗生素的去除，而非自由基途径占据主导地位。本文旨在推动高级氧化技术（advanced oxidation technology）去除磺胺类抗生素的基础理论发展与完善，更好地服务于水生态系统管理与环境问题的解决。