二氧化氯和臭氧对吉非贝齐的降解机制

Degradation mechanism of gemfibrozil by chlorine dioxide and ozone

吉非贝齐(GFRZ)为常见的脂质调节剂,广泛应用于高血脂病患的治疗.GFRZ对水生生物存在内分泌干扰活性,由其造成的潜在生态环境风险备受关注.本文研究了二氧化氯(ClO2)和臭氧(O3)体系中GFRZ的降解机制及影响因素.结果表明,ClO2及O3均可有效去除水中的GFRZ,氧化剂浓度、温度、pH值及腐殖酸均影响GFRZ的降解过程;增加ClO2投加量可显著提高GFRZ的去除率(P<0.01);提高温度可促进ClO2体系中GFRZ的降解,而O3体系中,温度升高使O3的浓度降低,GFRZ的去除率降低;酸性及中性条件下GFRZ在ClO2体系中的降解效果优于碱性条件,而在O3体系中,随着pH值升高(pH=3—11),GFRZ的去除率呈先增加后减小的趋势;反应体系中的腐殖酸与GFRZ竞争氧化性基团,从而抑制GFRZ的降解过程(P<0.05).在ClO2及O3体系中,在氧化性基团的作用下,GFRZ分子的支链首先断开,继而被进一步氧化,发生开环及断键,生成小分子有机酸.

Gemfibrozil(GFRZ),a common lipid regulator,is widely used in the treatment of hyperlipidemia.The potential ecological risk caused by GFRZ has attracted much attention because of its endocrine disruptive activity to aquatic organisms.The degradation mechanism and influencing factors of GFRZ in chlorine dioxide(ClO2)and ozone(O3)systems were studied.The results showed that GFRZ was removed effectively by ClO2 and O3 from water.The degradation process of GFRZ was affected by factors such as oxidant concentration,temperature,pH value and humic acid.The removal rate of GFRZ was significantly increased by increasing ClO2 dosage(P<0.01).In ClO2 system,the degradation of GFRZ was promoted by temperature increasing,while in O3 system,the concentration of O3 decreased with temperature increasing,which reduced the removal of GFRZ.Under acidic and neutral conditions,the degradation effect of GFRZ in ClO2 system was better than that in alkaline condition.While in O3 system,the removal rate of GFRZ increased first and then decreased when pH value increased from 3 to 11.And humic acid in the reaction system competed with GFRZ for oxidizing groups,which inhibited the degradation of GFRZ(P<0.05).In ClO2 and O3 systems,the branched chain of GFRZ molecule was first broken by oxidizing groups,and then further oxidized to open and break bonds,resulting in the formation of small molecular organic acids.