欢迎访问《环境科学学报》编辑部网站！

快速检索			高级检索

本期目录

孙浩堯,陈庆彩,牟臻,王羽琴,沈振兴,张立欣,李艳广.西安地区PM_2.5中环境持久性自由基(EPFRs)性质及来源研究[J].环境科学学报,2019,39(1):197-203

Study on the properties and sources of environmental persistent free radicals (EPFRs) in PM_2.5 in Xi'an

基金项目：国家自然科学基金（No.41703102）；陕西省自然科学基金面上项目（No.2018JM4011）；陕西省自然科学基金青年项目（No.2017JQ5115）

摘要：环境持久性自由基（environmental persistent free radicals， EPFRs）是一种近年来备受关注的环境风险物质，可能会危害人体健康.本研究利用溶剂萃取方法从西安市大气PM_2.5样品中分离出物质，运用电子顺磁共振波谱（EPR）技术分析了不同大气污染状况下大气PM_2.5样品及类黑碳成分中EPFRs的种类和含量，并分别测定PM_2.5和类黑碳成分催化H₂O₂产生羟基自由基的能力.结果表明：PM_2.5中的EPFRs约有85%~90%是由类黑碳成分产生的.可见光照（400~700 nm）前后，PM_2.5样品中EPFRs的含量增加10%~20%. 此外，实验结果亦表明PM_2.5中能催化H₂O₂产生羟基自由基的物质主要是PM_2.5中水溶性物质而不是类黑碳.大气PM_2.5中的EPFRs没有显著催化H₂O₂产生羟基自由基的能力，也不能将O₂分子转化为活性氧物质.

Abstract：Environmental persistent free radicals (EPFRs) are environmental risk substances that have received much attention in recent years, which may have serious effects on human health. In this study, a solvent-extraction method was used to separate the BC-like (black carbon like) substance from the atmospheric PM_2.5 samples in Xi'an. The types and concentrations of EPFRs in PM_2.5 and BC-like substance were analyzed under different atmospheric pollution conditions with electron paramagnetic resonance (EPR) spectroscopy, respectively as well as the ability of catalyzing H₂O₂ to generate hydroxyl radicals. The results showed that about 85%~90% of the EPFRs in PM_2.5 were produced by the BC-like substance. Before and after the visible light (400~700 nm), the content of EPFRs in PM_2.5 increased by 10%~20%. In addition, it was found that the substances who could catalyze H₂O₂ to generate hydroxyl radicals in PM_2.5 were mainly water-soluble substances rather than BC-like substance. And this experiment also found that EPFRs in atmospheric PM_2.5 neither had significant ability to catalyze H₂O₂ to generate hydroxyl radicals nor converted O₂ molecules to generate reactive oxygen species.