【摘要】 随着多种传统溴代阻燃剂的全面禁用,新型溴代阻燃剂（NBFRs）应运而生。近年来NBFRs造成的环境与健康问题日益凸显,其环境行为和持久性引起了人们的普遍关注。以污染较严重的1,2-二（2,4,6-三溴苯氧基）乙烷（BTBPE）作为典型NBFRs,采用实验和理论计算相结合的方法,研究其在不同溶剂环境中的光降解动力学,探索有机溶剂的物理化学性质与BTBPE光降解速率之间的相关性规律,并延伸到四氢呋喃（THF）与H₂O的混合体系,以探讨自然水体中BTBPE可能的光降解速率与环境持久性。结果表明:BTBPE的光降解速率受有机溶剂的影响较大,其半衰期从正己烷溶剂中的16.53 min到乙腈溶剂中的53.32 min不等。这是由于不同有机溶剂会影响BTBPE的摩尔吸光强度,进而改变激发态BTBPE（BTBPE*）的产率,最终影响BTBPE的光降解速率和半衰期。因此,BTBPE*的产率是决定BTBPE光降解速率的主要因素,而电子转移反应和加氢反应对BTBPE光降解反应的影响较小。同时,通过H₂O和THF的混合体系模拟试验发现,随着H₂O含量的增加, BTBPE的光降解速率迅速降低,表明BTBPE在自然水体环境中的光降解速率可能非常缓慢,是潜在的环境持久性有机污染物。更多还原

【Abstract】 With the strict ban on many traditional brominated flame retardants（BFRs）,novel brominated flame retardants（NBFRs） have been produced and widely used.Its large production and usage have caused a series of environmental and health problems,which aroused widespread concern.In this study,one of the most abundant NBFRs,1,2-bis（2,4,6-tribromophenoxy） ethane（BTBPE）,was selected as a model to clarify the solvent effects on the photodegradation kinetics.The physical and chemical properties of the common organic solvents were analyzed.The role of H₂O in the mixed system of tetrahydrofuran（THF） and H₂O was investigated to explore the possible photodegradation kinetics in a natural aqueous environment.The results show that the photodegradation rate of BTBPE in diverse organic solvents is different and varied with the half-life（t1/2） of BTBPE ranging from 16.53 min in n-hexane to 53.32 min in acetonitrile.The main reason is that the organic solvent can affect the molar absorptivity of BTBPE,and then influence the yield of the excited BTBPE（BTBPE*）.These phenomena indicate that the main contributor that determines the photodegradation rate is the yield of the BTBPE*,but both hydrogen donating efficiency and electron donating efficiency of solvents were not the decisive factors for the photodegradation rate.The photodegradation rate of BTBPE in the mixed system of H₂O and THF will slow down rapidly with the increase of H₂O content,which suggests that the photodegradation rate of BTBPE in a natural aqueous environment may be very slow.Namely,BTBPE could be an emerging potential persistent organic pollutant.更多还原