有机质介导下微生物驱动稻田土壤中多溴联苯醚加速自然消减的作用机制

Polybrominated diphenyl ethers (PBDEs) are among the toxic contaminants released during the electronic-waste disposal activities. The wide area paddy fields around electronic-waste disposal workshops are the main receiver of PBDEs. Natural removal is an important environmental geochemical process for PBDEs in paddy field soils, however, the main process mechanisms have not been fully understood. Paddy field soils are usually irrigated for cultivation and containing high concentration of organic matters. Taking decabrominated diphenyl ether (BDE-209) as a model congener of PBDEs, this project aims to investigate the effect of organic matters in accelerating natural removal of BDE-209 in paddy field soils and to clarify the main process mechanisms mediated by organic matters of accelerating natural removal of PBDEs conducted by microorganism in paddy field soils. According to the characteristics of paddy field soils, the process contribution of possible mechanisms including electron transfer of the process of organic matter mineralization, electron shuttle of the process of humus respiration will be studied and further explore their interactions. The achievements of this project will provide scientific basis for in situ remediation of PBDEs contaminated paddy field soils and other similar sites contaminated by halogenated aromatic hydrocarbons.

多溴联苯醚(PBDEs)是电子垃圾拆解活动带来的一类重要污染物，电子垃圾拆解区周边面积广大的稻田是PBDEs的重要受纳体，自然消减是PBDEs在稻田土壤中重要的环境地球化学过程，但其主要作用机制仍不明确。本项目从电子垃圾拆解区稻田土壤中PBDEs加速自然消减的现象出发，以十溴联苯醚(BDE-209)为目标模型物，根据稻田土壤淹水耕作和高有机质含量的特性，研究不同模式有机质对BDE-209生物降解的影响及其作用机理，探讨有机质矿化过程和腐殖质呼吸过程对PBDEs呼吸脱溴及脱溴产物矿化的作用贡献，揭示有机质介导下微生物驱动稻田土壤中PBDEs加速自然消减的主要作用机制及其耦合机理。研究成果可为实施PBDEs污染稻田土壤原位修复提供理论依据，并为其他类似卤代有机物中低度污染土壤的修复提供思路。

多溴联苯醚(PBDEs)是电子垃圾拆解活动带来的一类重要污染物，电子垃圾拆解区周边面积广大的稻田是PBDEs的重要受纳体，自然消减是PBDEs在稻田土壤中重要的环境地球化学过程。本项目从电子垃圾拆解区稻田土壤中PBDEs加速自然消减的现象出发，以十溴联苯醚(BDE-209)为目标模型物，根据稻田土壤淹水耕作和高有机质含量的特性，研究不同模式有机质对BDE-209生物降解的影响及其作用机理，探讨了有机质矿化过程和腐殖质呼吸过程对PBDEs呼吸脱溴及脱溴产物矿化的作用贡献，揭示了有机质介导下微生物驱动稻田土壤中PBDEs加速自然消减的主要作用机制及其耦合机理。研究成果可为实施PBDEs污染稻田土壤原位修复提供理论依据，并为其他类似卤代有机物中低度污染土壤的修复提供思路。