颗粒物上十溴联苯醚的光降解反应  

Photodegradation of decabromodiphenyl ether adsorbed onto aerosol

作　　者：祖耕武[1,2] 文晟[1] 盛国英[1,3] 傅家谟[1,3] 

机构地区：[1]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广东省环境资源利用与保护重点实验室,广东广州510640 [2]中国科学院研究生院,北京100049 [3]上海大学环境与化学工程学院环境污染与健康研究所,上海200072

出　　处：《生态环境学报》2009年第1期205-209,共5页Ecology and Environmental Sciences

基　　金：中国科学院知识创新工程重要方向项目子课题(KZCX2-YW-403);国家自然科学基金重大项目三级子课题(40590391)

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 

分 类 号：X132[环境科学与工程—环境科学]