Guangzhou Institute of Building Science Group Co., Ltd., Guangzhou, 510440, China; South China University of Technology, Guangzhou, 510641, China.
State Key Laboratory of Urban Water Resource and Environment, School of Environment, Harbin Institute of Technology, Harbin, 150090, China.
Environ Res. 2023 Dec 15;239(Pt 1):117408. doi: 10.1016/j.envres.2023.117408. Epub 2023 Oct 13.
With the widespread use of sulfonamide antibiotics (SAs), SAs are detected as residues in aquatic environments, posing a serious threat to human life and safety. Because of their high water solubility, fast transmission rate, and strong antibacterial properties, the safe disposal of SAs has become a key constraint for water quality assurance. Therefore, an ultrasound (US)-assisted zero-valent iron (ZVI)/persulfate (PS) system was proposed to explore the rapid and effective degradation of SAs. Comparative experiments were performed to study the removal of sulfadiazine (SDZ) by US, ZVI, PS, US/ZVI, US/PS, ZVI/PS, and US-ZVI/PS systems, respectively. Experimental results indicated that the highest removal efficiency of SDZ was ahieved in US-ZVI/PS system (97.4%), which were 2-44 times higher than that in other systems. Furthermore, the degradation efficiency of five typical SAs was achieved over 95%, demonstrating the effectiveness of the US ZVI/PS system for SAs removal. Also, quantum chemical computations for potential reactive sites of SAs and intermediate product detection by HPLC‒MS/MS were performed. The radical attack on active sites of SAs, such as N atom (number 7), was the main reason for SAs removal in US-ZVI/PS system. Besides, the common degradation pathways of six typical SAs were defined as S-N bond cleavage, C-N bond cleavage, benzene ring hydroxylation, aniline oxidation, and R substituent oxidation. Interestingly, the unique pathway of "SO group extraction" was observed in the degradation of six-membered ring SAs. Therefore, the US-ZVI/PS system is a promising and cost-effective method for the removal of SAs and other refractory pollutants.
由于磺胺类抗生素（SAs）的广泛使用，SAs 作为残留物被检测到存在于水生环境中，对人类的生命和安全构成了严重威胁。由于其高水溶性、快速传递率和强抗菌性能，安全处理 SAs 已成为水质保证的关键制约因素。因此，提出了一种超声（US）辅助零价铁（ZVI）/过硫酸盐（PS）系统，以探索磺胺类药物的快速有效降解。进行了对比实验，分别研究了 US、ZVI、PS、US/ZVI、US/PS、ZVI/PS 和 US-ZVI/PS 系统对磺胺嘧啶（SDZ）的去除效果。实验结果表明，SDZ 的最高去除效率是在 US-ZVI/PS 系统中达到的（97.4%），比其他系统高 2-44 倍。此外，五种典型磺胺类药物的降解效率均超过 95%，证明了 US-ZVI/PS 系统对磺胺类药物去除的有效性。还进行了磺胺类药物潜在活性位点的量子化学计算和 HPLC-MS/MS 检测中间产物。US-ZVI/PS 系统中磺胺类药物去除的主要原因是自由基对磺胺类药物活性位点（如 7 号 N 原子）的攻击。此外，还确定了六种典型磺胺类药物的共同降解途径，包括 S-N 键断裂、C-N 键断裂、苯环羟化、苯胺氧化和 R 取代基氧化。有趣的是，在六元环磺胺类药物的降解过程中观察到了独特的“SO 基团提取”途径。因此，US-ZVI/PS 系统是去除磺胺类药物和其他难处理污染物的一种有前途且具有成本效益的方法。
