Ministry of Education Key Laboratory of Pollution Control and Ecological Remediation for Industrial Agglomeration Area, School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
College of Environment and Resources, Fuzhou University, Fuzhou, 350116, China.
Chemosphere. 2019 Apr;221:301-313. doi: 10.1016/j.chemosphere.2019.01.042. Epub 2019 Jan 7.
Polybrominated diphenyl ethers (PBDEs) are widely used as flame retardants and challenges for water treatment due to their persistence and toxicity. In this study, the reduction of 2'2'4'4'-tetrabromodiphenyl ether (BDE-47) was investigated in a nano-bio-integrated system. Results showed that the introducing of P. putida could markedly accelerate the demineralization of BDE-47 in nZVI/Pd-P.p system; the continuous generation of acidic metaboliates by P. putida could decrease pH, which could alleviate the surface passivation to some extent, resulting in the releasing of Fe and high generation of HO, the shift in reactive oxygen species from Fe(IV) to •OH. The BDE-47 was firstly debrominated to the DE by the highly reductive [Pd·2H] generated by nZVI/Pd, then oxidized to bromophenol and phenol, catechol as well as hydroquinone via the P. putida strain and the Fenton-like system. The toxicity assays confirmed the combined system could avert generation of nocuous intermediates, and could be an alternative strategy for complete remediation of recalcitrant POPs.
多溴联苯醚（PBDEs）作为阻燃剂被广泛使用，由于其持久性和毒性，给水处理带来了挑战。本研究在纳米-生物一体化系统中考察了 2'2'4'4'-四溴联苯醚（BDE-47）的还原情况。结果表明，引入铜绿假单胞菌可显著加速 nZVI/Pd-P.p 体系中 BDE-47 的脱矿作用；铜绿假单胞菌持续产生的酸性代谢物可降低 pH 值，在一定程度上减轻表面钝化，导致 Fe 的释放和高浓度的 HO 的生成，反应性氧物种从 Fe(IV)向 •OH 的转移。BDE-47 首先被 nZVI/Pd 生成的高还原性[Pd·2H]脱溴生成 DE，然后通过铜绿假单胞菌和类 Fenton 体系氧化生成溴苯酚、苯酚、儿茶酚和对苯二酚。毒性试验证实，该联合体系可避免生成有害中间体，为完全修复难降解持久性有机污染物提供了一种替代策略。
