6:2氟调磺酸在土壤中的有氧微生物转化  

Aerobic biotransformation of 6:2 fluorotelomer sulfonic acid in soil

作　　者：陈浩[1] 赵立杰 王宁 姚义鸣[1] 孙红文[1] Hao Chen;Lijie Zhao;Ning Wang;Yiming Yao;Hongwen Sun(Key Laboratory of Pollution Processes and Environmental Criteria,Ministry of Education,College of Environmental Science and Engineering,Nankai University,Tianjin 300350,China;Agro-Environmental Protection Institute,Ministry of Agriculture,Tianjin 300191,China;E.I.du Pont de Nemours&Company,Inc.,Newark 19714-6300,USA)

机构地区：[1]南开大学环境科学与工程学院,教育部环境污染过程与基准重点实验室,天津300350 [2]农业农村部环境保护科研监测所,天津300191 [3]E.I.du Pont de Nemours&Company,Inc.,Newark 19714-6300,USA

出　　处：《科学通报》2019年第33期3441-3448,共8页Chinese Science Bulletin

基　　金：国家自然科学基金(41573097,41603101,41807356);天津市自然科学基金(18JCQNJC09200);高等学校创新引智计划(T2017002)资助

摘　　要：全(多)氟烷基化合物作为主要的活性成分被广泛地应用于水成膜泡沫灭火剂中.在消防演习中,大量的6:2氟调磺酸(6:2 FTSA)及其前体物被释放到土壤及地下水等环境中,然而关于6:2 FTSA在土壤中的归趋和转化的研究仍存在较大的空白.本研究利用室内微宇宙实验探究了6:2 FTSA在好氧土壤中的降解行为.实验进行到90 d时,6:2 FTSA在灭菌对照组和降解实验组中均具有较好的质量平衡结果,分别达到97.4%和76.8%. 6:2 FTSA在好氧土壤中的降解率较低, 90 d时仍有33%没有发生降解. 6:2 FTSA经一系列好氧降解转化,主要降解转化为短链的全氟戊烷羧酸(PFPeA)和全氟己烷羧酸(PFHxA),在另一次要的降解路径中则观察到5:3氟代饱和酸(5:3 acid)的生成.90 d时, PFPeA的生成产率占初始6:2 FTSA的摩尔百分比为20.4%, PFHxA为6.5%, 5:3 acid为9.5%,全氟丁烷羧酸(PFBA)为1.0%. 6:2 FTSA及其降解产物在土壤上的吸附能够降低其降解量.脱磺酸基步骤是6:2 FTSA在土壤中好氧降解的限速步骤.这些研究结果表明,进入到土壤环境中的6:2 FTSA可能是短链羧酸的一个潜在来源.Per-and polyfluoroalkyl substances(PFASs) have been widely used in numerous industrial and household products due to its hydrophobic and lipophobic nature. As the main active ingredient, PFASs have been widely used in aqueous film forming foam(AFFF) used to fight liquid-fueled fires. As the electrochemical fluorination(ECF)-based PFASs were gradually phased out by major PFAS manufacturers worldwide, fluorotelomer-based PFASs, such as 6:2 fluorotelomer sulfonic acid(6:2 FTSA, [F(CF2)6 CH2 CH2 SO3 H]) and its precursors, have been widely detected in soil and groundwater effected by firefighting training activities. A few precursors(e.g., 6:2 fluorotelomer alcohol, 6:2 FTOH, [F(CF2)6 CH2 CH2 OH]) have been well studied, but there are still leaving major gaps in understanding of 6:2 FTSA fate and aerobic biotransformation in soil. Soil collected from forest area was dosed with 6:2 FTSA to investigate its biotransformation rate and to identify major transformation products in a flow-through soil incubation system over 90 d. The overall mass balance at day 90 in sterile and live treatments averaged 97.4% and 76.8%, respectively, suggesting that there may be soil-bound residues and conjugates between fluorinated transformation products and dissolved soil components only in live test system not in the sterile soil. The 6:2 FTSA biotransformation was relatively low with a half-life more than 56 d, and 33% of initial 6:2 FTSA remained at day 90. According to the transformation products and the results in 6:2 FTSA biodegradation, the pathways of 6:2 FTSA aerobic biodegradation in the soil were proposed. The volatile 5:2 secondary alcohol(5:2 sFTOH,[F(CF2)5 CH(OH)CH3]) and 5:2 fluorotelomer ketone(5:2 FT ketone, [F(CF2)5 COCH3]) were the most abundant intermediate transformation products at the beginning, and reached highest at day 7 and 14, respectively.Perfluoropentanoic acid(PFPeA, [F(CF2)4 COOH]) and perfluorohexanoic acid(PFHxA, [F(CF2)5 COOH]) were produced as end products by 6:2 FTSA through desulfonation, oxidation a

关 键 词：6氟调磺酸 全氟羧酸 5氟代饱和酸 好氧生物转化 土壤 

分 类 号：O62[理学—有机化学]