复合二氧化氯对药物及个人护理品的降解效能

Degradation efficiencies of composite chlorine dioxide on pharmaceuticals and personal care products

药物及个人护理品(PPCPs)在水处理工艺中的迁移转化备受关注.二氧化氯(ClO2)是一种常用的消毒剂,但水厂中二氧化氯制备工艺得到的常为复合二氧化氯(即ClO2和Cl2的混合物).目前,复合二氧化氯对PPCPs的去除方面研究还比较缺乏.本文研究了复合二氧化氯对16种常见PPCPs的降解效能,并与单独二氧化氯氧化进行比较.研究发现,PPCPs的降解效果与其化学结构密切相关.ClO2可选择性氧化磺胺甲基嘧啶等含富电子基团的PPCPs,对甲硝唑等不含富电子基团的PPCPs降解能力有限,对咖啡因和扑米酮基本不降解.相比单独二氧化氯氧化,复合二氧化氯能促进萘啶酸、氟甲喹和对乙酰氨基酚的降解,但是对甲硝唑、二甲硝咪唑和避蚊胺的降解能力低于单独二氧化氯氧化.复合二氧化氯使用中亚氯酸盐生成量降低.

It is important to understand the transport and transformation of pharmaceuticals and personal care products(PPCPs)in water and wastewater treatment.Chlorine dioxide(ClO2)is a commonly used disinfectant,but ClO2 generator often produces the mixture oxidant of ClO2 and Cl2.The removal efficiency of PPCPs using the mixture oxidant of ClO2 and Cl2 is not well understood yet.In this study,the degradation efficiency of sixteen PPCPs using the mixture oxidant of ClO2 and Cl2 was studied and compared with that of ClO2 alone.It was found that the degradation efficiency of PPCPs was closely related to their chemical structures.ClO2 selectively oxidizes PPCPs containing electron rich groups such as sulfamerazine,while it had limited degradation ability for PPCPs without electron rich groups such as metronidazole,and did not degrade caffeine and primidone.ClO2/Cl2 mixing oxidant promoted the degradation of nalidixic acid,fluquinoline and acetamidophenol,whereas the degradation of metronidazole,dimetridazole and diethyltoluamide was lower than that of ClO2 alone.The combined use of ClO2 and Cl2 could reduce the formation of chlorite.