【作者】 赵冬梅；

【导师】 乔显亮；

【作者基本信息】 大连理工大学 ， 工业生态与环境规划， 2010， 硕士

【摘要】 多溴联苯醚(Polybrominated diphenyl ethers, PBDEs)是一种常用的添加型溴代阻燃剂。很多研究表明,PBDEs已广泛存在于各个环境介质中,并且已在生物及人体中检出。数据显示,环境中PBDEs的浓度水平呈逐年上升的趋势。PBDEs具有长距离迁移性、生物蓄积性等特征,2009年5月,全球160多个国家和地区达成共识,将五溴工业品中的四溴联苯醚和五溴联苯醚组分以及八溴工业品中的六溴联苯醚和七溴联苯醚组分作为新的持久性有机污染物列入斯德哥尔摩公约。DOM是环境中普遍存在的一种天然成分。前人研究表明,DOM对很多污染物(包括重金属和多种有机污染物)的环境行为和生态风险具有重要影响。DOM的存在会显著的增加疏水性有机污染物的表观溶解度,改变其生物有效性,影响其迁移和扩散,提高其环境风险。PBDEs具有典型的疏水性有机污染物的特征,研究DOM与PBDEs的结合,对于揭示PBDEs在环境中的行为,评价其生态风险具有重要意义。本研究采用平衡透析法,测定了若干PBDEs同类物(BDE-28、BDE-47、BDE-77、BDE-99、6-F-BDE-47,5-MeO-BDE-47)与几种代表性可溶性有机质(Leonardite Humic Acid Standard, Aldrich Humic Acid, Elliott Soil Humic Acid Standard, Suwannee River Fulvic Acid Standard)的结合常数(KDOC),分析了DOM浓度和属性对其与PBDEs结合的影响。结果表明,DOM存在条件下,所研究PBDEs的表观溶解度都有显著的增大；DOM浓度越高增溶效应越显著。不同DOM与PBDEs的结合能力相差很大,结合常数(KDOC)与DOM分子中芳香性碳的比例显著有关。陆源的DOM与PBDEs的结合比水源的强。对于五溴以下的同类物,PBDEs与DOM的结合随溴原子数目增加而增强；溴取代位点对BDE的KDOC常数表现出显著影响,F-,MeO-等取代基的引入对其结合能力也表现出一定的影响。对于单一的BDE与五溴工业PBDEs中对应的BDE同类物对比表明,二者与DOM结合能力有一定差别,但整体趋势一致。本研究表明,DOM对PBDEs的环境行为和生态风险会有重要影响,值得深入系统研究。更多还原

【Abstract】 Polybrominated diphenyl ethers (PBDEs) are widely used as additive brominated flame retardents (BFRs). PBDEs have been detected in lots of environmental and biota (including people) samples, and the level of PBDEs in the environment and biota presents obvious increasing trend. PBDEs have shown similar characteristics as persistent organic pollutants, such as long-distance transport, bioaccumulation. Tetra-, penta-, hexa-and hepta-BDEs are listed in the POPs by UNEP in May,2009.DOM (dissolved organic matter) is ubiquitous composition in environment, which was documented to be an important factor to affect the environmental behavior and ecological risk on a lot of pollutants (including heavy metals and organic pollutants). It was shown that DOM can increase the apparent solubility of hydrophobic organic compounds, change their bioavailability, enhance their transport and spread, thus increase their ecological risk. PBDEs show typical characteristics of hydrophobic organic compounds. Studying the interaction between DOM and PBDEs will be helpful to understand the environmental behaviors and to assess the ecological risk of PBDEs.In this study, equilibrium dialysis technique was used to determine the PBDEs-DOM partition coefficients (KDOC). PBDEs congeners (BDE-28, BDE-47, BDE-77, BDE-99,6-F-BDE-47, 5-MeO-BDE-47) and several kinds of DOM (Leonardite Humic Acid Standard, Aldrich Humic Acid, Elliott Soil Humic Acid Standard, and Suwannee River Fulvic Acid Standard) were applied. The influences of BDE congener, and DOM properties to the partition coefficients were examined.Results showed that DOM can significantly increase the apparent solubility of BDE congeners tested, and the enhancement was concentration-dependent for DOM. There is distinct difference on the binding ability for various DOM materials, and aromatic carbon in DOM molecular was inferred to be a key factor on the contribution of KDOC.Terrestrial DOM demonstrated stronger interaction with PBDEs than aquatic DOM. For tri-to penta-BDE congeners, the binding ability with DOM increase with Br number, and the substitution sites show significant influence on the KDOC coefficients. Other substitution function groups like F-, MeO-also showed some contributions. The KDOC obtained from single BDE congener exerted little difference from values gotten from the corresponding congener in penta-BDE technical mixtures, and the major trend between the congeners tested was quite similar. It was proved that DOM can notablly affect the behaviors and ecological risks of PBDEs, which worth further research efforts.更多还原