作　　者： ; ; ; ;

机构地区： 中国科学院广州地球化学研究所有机地球化学国家重点实验室

出　　处： 《生态环境学报》 2009年第1期205-209,共5页

摘　　要： 多溴联苯醚(PBDEs)是一类全球性的有机污染物,由于其持久性、毒性和潜在的生物累积性而备受关注。商业上主要使用的是十溴联苯醚(BDE-209),但是环境中检测出大量的较低溴代联苯醚,有可能来源于环境中BDE-209的光化学降解。研究在自行设计的光降解反应装置中,以太阳光和紫外灯(主波长为365nm)为光源,对负载在硅胶和氧化铝上的BDE-209进行照射实验。光照6h后发现,负载在硅胶上的BDE-209(0.2mg·g-1)在太阳光照射下,半衰期为35min,而在紫外灯下仅为10min;在紫外灯照射下负载在硅胶和氧化铝上的BDE-209(0.4mg·g-1)的半衰期为18min。在不同光源或颗粒物中,BDE-209都发生了脱溴反应,生成较低溴代产物。暗反应表明,负载在硅胶和氧化铝上的BDE-209都没有发生光降解。这些结果表明,吸附在颗粒物气溶胶上BDE-209的光降解反应,可能是环境中BDE-209的一个重要归趋,同时,其产物可能是环境中低溴代联苯醚的一个重要来源。 As a group of persistent organic pollutants with global influence, Polybrominated diphenyl ethers （PBDEs） have received considerable attention due to its environmental persistence, toxicity and potential bioaccumulation. Although decabromodiphenyl ether （BDE-209） is one of the most widely used PBDEs, various lower brominated diphenyl ethers （LBDEs） with even higher concentrations than BDE-209 are detected in biota. Photochemical degradation is considered to be an important contribution to the formation of LBDEs. In the present study, BDE-209 was loaded onto the silica and alumina particles. The photodebromination of BDE-209 was carried out in a self-designed reactor under sunlight or UV light （365 nm） irradiation. After 6 hours irradiation, it was found that the half-life of BDE-209 （0.2 mg·g-1） on silica was 35 minutes under sunlight compared to 10 minutes under UV while BDE-209 （0.4 mg·g-1） on silica and alumina possessed a half-life of 18 minutes under UV. The debromination of BDE-209 loaded on different particles was found under both sunlight and UV irradiation, accompanied by the formation of LBDEs. Dark control experiment indicated that BDE-209 was stable without light irradiation. The present study shows that the photodegradation of BDE-209 on mineral aerosols may be an important environmental transform for BDE-209 and also an important source of LBDEs in environment.

关 键 词： 十溴联苯醚 光降解 脱溴 太阳光 颗粒物

领　　域： [环境科学与工程]