摘要
四溴双酚A(tetrabromobisphenol A, TBBPA)在各种氧化还原状态土壤中均可形成大量的不可提取态残留(nonextractable residues, TBBPA-NER).然而TBBPA-NER在环境中的稳定性和生物可利用性目前还鲜见报道.本研究以TBBPA在淹水条件和有氧条件下分别形成的不可提取态残留(即flooded-nonextractable residues, F-NER和oxicnonextractable residues, O-NER)为研究对象,分析了有氧条件下F-NER的归趋,以及土壤氧化还原状态改变下, FNER和O-NER环境行为的差异;同时研究了水稻根系分泌物对上述过程的影响.结果显示,有氧条件连续培养231 d中, F-NER在土壤中发生了缓慢的生物转化.尽管F-NER在土壤中释放出的可提取态量很低(1%~6%),但是矿化>10%,且酯键和醚键结合部分有所消减.土壤氧化还原状态的改变(即0~50 d有氧, 50~103 d淹水, 103~231 d有氧)对F-NER的矿化影响很小;而TBBPA-NER在土壤中的降解转化受形成条件影响较大,表现为有氧-淹水-有氧培养下F-NER的矿化量,以及释放量均显著高于O-NER. F-NER受环境因素的影响更大,水稻根系分泌物抑制了FNER在有氧环境下的矿化,而淹水条件促进了F-NER的释放产物在土壤中的累积.结果证明,土壤中添加根系分泌物以及氧化还原状态转变等,在不同程度上影响了两种NER在土壤中的生物转化.
Tetrabromobisphenol A(TBBPA) is a kind of widely used brominated flame retardants. After entering to the soil,considerable TBBPA and its metabolites can form non-extractable residues(NER) under the flooded condition(F-NER)and oxic condition(O-NER). However, little is known about the stability and environmental behavior of these NERs in soil after long-term incubation. In this study, two14 C-TBBPA-NERs was used to study:(1) The fate of F-NER in oxic and oxicflooded-oxic soil including their releasing, mineralization, degradation and the distribution of14 C in soil matrix in the presence or absence of rice root exudate;(2) the biotransformation different between the F-NER and O-NER in oxicflooded-oxic soil in the presence or absence of rice root exudate. During 231 d incubation, slow biotransformation of FNER was observed in oxic soil. More than 10% of F-NER was mineralized accompanied by the releasing of ester and etherlinked NER, while the extractable TBBPA and its metabolites kept quite low during the incubation(1%-6%). In addition,the appearance of rice root exudate inhabited the mineralization of F-NER in oxic soil at the end of the experiment. In oxicflooded-oxic incubation, the mineralization of F-NER is consistent with oxic condition, while the more extractable radioactivity was observed in soil extracts during the flooded incubation. We proposed that higher extractable14 C may attribute to the released dibrominated products and BPA tended to accumulated in flooded soil, and these extractable residues removed fast after soil turns into oxic condition. Meanwhile, O-NER was more stable than F-NER in soil presented as lower mineralization and releasing of TBBPA and its metabolites during the incubation, and further analysis showed that ester and ether-linked NER also decreased slower in O-NER treatment. No obvious extractable14 C accumulated in soil extract during the flooded incubation. O-NER was more persistent in soil after long-term incubation than F-NER may attribute to the metabolism of TBBPA is differen
作者
王松凤
吴玄
王麒麟
王永峰
王联红
Philippe Fran?ois-Xavier Corvini
孙棐斐
季荣
Songfeng Wang;Xuan Wu;Qilin Wang;Yongfeng Wang;Lianhong Wang;Philippe Francois-Xavier Corvini;Feifei Sun;Rong Ji(State Key Laboratory of Pollution Control and Resource Reuse,School of the Environment,Nanjing University,Nanjing 210023,China;Institute of Botany,Jiangsu Province and Chinese Academy of Sciences,Nanjing 210014,China;Institute for Ecopreneurship,School of Life Sciences,University of Applied Sciences and Arts Northwestern Switzerland,Muttenz,CH 4132,Switzerland)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2019年第33期3458-3466,共9页
Chinese Science Bulletin
基金
国家自然科学基金(21806061,21607071)
国家重点研发计划(2016YFD0800200)资助
关键词
四溴双酚A
不可提取态残留
根系分泌物
氧化还原条件
释放
tetrabromobisphenol A(TBBPA)
nonextractable residues
root exudate
redox potential
releasing
