羟胺强化Cu(Ⅱ)/过硫酸盐降解医疗废水中土霉素

Hydroxylamine enhanced Cu(Ⅱ)/persulfate degradation of oxytetracycline in medical wastewater

抗生素类药物使用广泛且用量较大。其进入人体或动物体内后,可以母体结构或代谢产物形态排出体外,直接或间接进入环境并长期积累,对生态环境和人体健康构成危害。采用羟胺(HA)强化Cu(Ⅱ)/过硫酸盐体系对医疗废水中的土霉素(OTC)进行降解,研究其降解效率、影响因素及降解机理,并对降解路径进行分析。结果表明,Cu(Ⅱ)和HA的偶联可有效活化过硫酸盐(PDS)氧化降解OTC。HA、Cu(Ⅱ)浓度的提升有利于提高降解率,高浓度的PDS也可以增强OTC的降解效果,但过量PDS会造成活性氧物种损失。初始pH由3.0提升至5.0时,OTC降解率明显增加,随着pH进一步增加到7.0,OTC的降解受到明显抑制。SO_(4)^(·-)和·OH是体系中降解OTC的主要活性氧物种。OTC的转化主要通过羟基化、脱甲基化、脱羰基化和脱水反应途径进行。

Antibiotics are widely used in large dosage.After entering the human or animal body,antibiotic can be discharged in form of parent drug or metabolites,directly or indirectly into the environment and accumulate over time,which is harmful to the ecological environment and human health.The oxytetracycline(OTC)in medical wastewater was degradated by Cu(Ⅱ)/persulfate system reinforced with hydroxylamine(HA).The degradation efficiency,influencing factors and degradation mechanism were studied,and the degradation paths were analyzed.The results showed that the coupling of Cu(Ⅱ)and hydroxylamine(HA)can effectively activate persulfate(PDS)to oxidize OTC.The increases of HA,Cu(Ⅱ)concentration were conducive to improve the degradation efficiency,and high concentration of PDS could also enhance the degradation effect of OTC,but excessive PDS would cause the loss of reactive oxygen species.When the initial pH increased from 3.0 to 5.0,the degradation of OTC significantly increased,while when the pH further increased to 7.0,the degradation of OTC was significantly inhibited.SO_(4)^(·-)and HO·were the main reactive oxygen species that degrade OTC in the system.OTC was transformed by hydroxylation,demethylation,decarboxylation and dehydration mainly.