敖蒙蒙 刘利 魏健 宋永会 陈婷婷 熊兆锟 赖波 陈忠林

摘 要：为考察β-内酰胺类抗生素在臭氧氧化过程中的降解规律与特征，采用臭氧直接氧化法处理水中4种典型β-内酰胺类抗生素。研究不同pH值条件下臭氧氧化典型β-内酰胺类抗生素的降解效果，利用淬灭实验探究降解机理，分析中间产物并推测降解路径。研究结果表明：改变pH值对阿莫西林和头孢氨苄降解效果没有显著影响，酸性条件对青霉素钠降解有抑制，碱性条件对头孢曲松钠降解有促进。淬灭实验结果表明：叔丁醇（TBA）对阿莫西林和头孢氨苄的降解有一定的促进作用，说明阿莫西林和头孢氨苄的降解由臭氧分子直接氧化主导;随着TBA浓度的升高，对青霉素钠和头孢曲松钠的抑制效果更加显著，说明青霉素钠和头孢曲松钠以羟基自由基（·OH）间接氧化为主导。阿莫西林、头孢氨苄、青霉素钠和头孢曲松钠臭氧氧化过程中分别生成了4、6、3、3种主要中间产物，降解途径包括β-内酰胺环断裂、去甲基化、水合反应、加成反应等过程。

关键词：β-内酰胺类抗生素;臭氧;中间产物;降解途径

中图分类号：X703.1 文献标志码：A 文章编号：2096-6717（2021）06-0187-10

Abstract： In order to investigate the degradation law and characteristics of β-lactam antibiotics during ozone oxidation， four typical β-lactam antibiotics in water were treated by direct ozone oxidation. The degradation effect of ozone on typical β-lactam antibiotics under different pH values was studied. Quenching experiments were adopted to explore the degradation mechanism，analyze intermediates and speculate the degradation path. Results showed that the degradation of amoxicillin and cephalexin was not significantly affected by changing pH， penicillin sodium was inhibited in acidic condition， and ceftriaxone sodium was promoted in alkaline condition.The results of quenching experiments showed that TBA can promote the degradation of amoxicillin and cephalexin， indicating that the degradation of amoxicillin and cephalexin was dominated by direct oxidation of O3.With the increase of TBA concentration， the inhibition effect to penicillin and ceftriaxone sodium was more and more significant， which indicated that penicillin and ceftriaxone sodium were indirectly oxidized by ·OH.Amoxicillin， cephalexin， penicillin sodium and ceftriaxone sodium produced 4， 6， 3 and 3 main intermediates during ozonation， respectively. The degradation pathways were composed of β-lactam ring breaking， demethylation， hydration and addition etc.

Keywords： β-lactam antibiotics; ozone oxidation; intermediates; degradation pathway

自發现青霉素以来，β-内酰胺类抗生素被广泛应用于医学、生物学、生物化学、生命科学、农业等领域[1]。由于人或动物对抗生素消耗量大、代谢量小，大量β-内酰胺类抗生素通过人体后直接排放到环境中[2]。德国联邦化学品安全委员会的一项研究表明，在超过50%的废水和地表水样本中检测出最大浓度在ng/L范围的β-内酰胺类抗生素[3]。……