腐殖酸与铁矿物对在淹水干旱交替作用下土壤-植物根际微域中多溴联苯醚迁移行为的影响机制

The rapid development of electronic industry leads to polybrominated diphenyl ethers (PBDEs) as one of emerging pollutants have been widely detected in the environment. Therefore, PBDEs migration in the soil- plant system has been highly concerned at home and abroad. Humic acid and iron minerals are important components of soil, which have important effects on the occurrence formation, biodegradation and plant uptake of pollutants. In the present project, the BDE-153 will be taken as a typical target compound, the effects of humic acid and iron minerals on BDE-153 migration mechanisms will be investigated under the sequential submerged-droughty conditions, because the soil can experience two processes such as an aerobic oxidation and anaerobic reduction in natural conditions. The migration mechanisms of BDE-153 under the sequential submerged-droughty conditions was discussed mainly through the internal relations between different fractions of humic acids, iron cycles and morphology of iron oxide, soil microbial community structure, iron plaque, root fatty acid, and behaviours of BDE-153 biodegradation/uptake in the plant root system. Additionally, the biodegradation mechanisms and pathway will be compared to that in the aerobic or anaerobic condition alone. It can explain the differences between the BDE-153 pathways in the soil- plant systems under aerobic oxidation and anaerobic reduction and that of aerobic oxidation or anaerobic reduction. It can help to reveal the essence of PBDE migration in the field soil- plant system. Moreover, it can deepen the understanding of migration mechanisms on the halogenated organic pollutants in the field environment.

电子产业的快速发展，导致新型污染物多溴联苯醚(PBDEs)在环境中被广泛检出。因此，PBDEs在土壤植物体系中迁移转化受到了国内外高度关注。腐殖酸和铁矿物是土壤重要组成部分，且对污染物赋存状态、微生物降解和植物吸收有着重要影响。项目以典型BDE-153为目标化合物，在土壤淹水干旱交替作用下，探讨土壤不同级分腐殖酸与铁矿物中铁循环过程对BDE-153在土壤植物根部迁移机制的影响。主要通过淹水-干旱变换过程中，土壤不同级分腐殖酸、铁氧化物铁循环和形态、根系微生物群落结构、植物根表铁膜、根部脂肪酸、BDE-47吸附/降解/植物根部吸收之间内在联系，阐述BDE-153在土壤-植物根部迁移机制与BDE-153在好氧或厌氧单一条件下迁移机制之间的差异，揭示PBDEs在实际土壤-植物根部迁移转化的实质过程，加深对卤代类有机污染物在土壤向植物根部迁移机制的认识。

电子产业的快速发展，导致新型污染物多溴联苯醚(PBDEs)在环境中被广泛检出。因此，PBDEs在土壤植物体系中迁移转化受到了国内外高度关注。腐殖酸和铁矿物是土壤重要组成部分，且对污染物赋存状态、微生物降解和植物吸收有着重要影响。项目以典型BDE-153为目标化合物，探讨土壤不同级分腐殖酸与铁材料中铁循环过程对BDE-153在土壤植物根部迁移机制的影响。主要通过选取铁电气石、针铁矿和负载铁生物炭，研究土壤不同级分溶解性腐殖酸和铁矿物交互作用对BDE-153赋存状态显示一级腐殖酸比四级抑制作用明显；根系微生物能提高植物根本BDE-153微生物降解；不同级分HA与电气石共同作用影响了植物脂类、Fe含量分别与BDE-153吸收的相关性，铁迁移和BDE-153在植物中吸收呈正相关，且HA4对植物脂类与BDE-153吸收相关性影响程度较HA1大；根系铁膜抑制植物脂肪酸组成及含量，促进BDE-153还原脱溴，并与脂肪酸竞争吸附目标物，干扰BDE-153在农作物中的迁移行为。负载铁生物炭能促进植物根系差异蛋白表达与相关生物学过程变化。该研究揭示土壤不同级分腐殖酸、铁材料中铁循环和形态、根系微生物群落结构、根表铁膜、根部脂肪酸、BDE-153赋存状态/降解/植物根部吸收之间内在联系，揭示铁膜和脂肪酸在PBDEs土壤-植物根部迁移转化的影响机制，加深对卤代类有机污染物在土壤向植物根部迁移所受土壤组分影响的关键机制。