State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China.
State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, China; School of Resources and Environmental Engineering, Hefei University of Technology, Hefei, 230000, China.
Environ Pollut. 2020 Jun;261:114214. doi: 10.1016/j.envpol.2020.114214. Epub 2020 Feb 19.
The quantitative fate of polybrominated diphenyl ethers (PBDEs) in soil is unknown. Furthermore, the effects of co-contamination by toxic copper on the behavior of PBDEs have not been investigated. Using a C-tracer, we studied mineralization, metabolism, and formation of non-extractable residues (NERs) of one PBDE congener, i.e., the 4-bromodiphenyl ether (BDE3) in oxic soil for 50 days, without and with amendment of Cu (400 mg kg soil dw). BDE3 rapidly dissipated with a half-life of 5.5 days and large amounts of CO (38.8 ± 0.3% of initial applied amount at the end of incubation) and NERs (42.5 ± 0.4%) were rapidly produced. One hydroxylated metabolite (4'-HO-BDE3) was formed (8.1 ± 0.6%) at the beginning of the incubation, but then decreased to 2.2 ± 0.4%. Only BDE3 occurred in physico-chemically entrapped NERs, amounting to 9.2 ± 0.7%, while only 4'-HO-BDE3 in ester-linked NERs (10.9 ± 0.7%). The addition of Cu strongly reduced the kinetics constants of the transformations (including dissipation, mineralization, and NER-formation), the predicted maximal amounts of mineralization, as well as covalent binding of 4'-HO-BDE3 to soil. The results provide first quantitative insights into the fate of low-brominated congeners of PBDEs in soil and indicate that co-contamination by Cu may increase the environmental risks of biodegradable PBDEs in soil by increasing their persistence.
多溴二苯醚（PBDEs）在土壤中的定量归宿尚不清楚。此外，有毒铜共同污染对 PBDEs 行为的影响尚未得到研究。本研究使用 C 示踪剂，在有氧土壤中研究了一种 PBDE 同系物，即 4-溴二苯醚（BDE3）的矿化、代谢和非提取残留物（NERs）的形成，在 50 天内，没有和有 Cu（土壤干重 400mg/kg）的添加。BDE3 迅速降解，半衰期为 5.5 天，大量 CO（培养结束时初始施加量的 38.8±0.3%）和 NERs（42.5±0.4%）迅速产生。在培养开始时形成了一种羟基代谢物（4'-HO-BDE3）（8.1±0.6%），但随后降至 2.2±0.4%。只有 BDE3 出现在物理化学固定的 NERs 中，占 9.2±0.7%，而只有 4'-HO-BDE3 出现在酯键合的 NERs 中（10.9±0.7%）。Cu 的添加强烈降低了转化的动力学常数（包括消解、矿化和 NER 形成）、预测的最大矿化量以及 4'-HO-BDE3 与土壤的共价结合。结果首次提供了关于低溴 PBDEs 同系物在土壤中归宿的定量见解，并表明 Cu 的共同污染可能通过增加可生物降解 PBDEs 的持久性而增加其在土壤中的环境风险。
