School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China.
School of Environment and Energy, South China University of Technology, Guangzhou, 510006, China; The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters, Ministry of Education, Guangzhou, 510006, China.
Chemosphere. 2020 Aug;253:126726. doi: 10.1016/j.chemosphere.2020.126726. Epub 2020 Apr 9.
We synthesized a novel material, namely palladized zero-valent zinc (Pd/ZVZ), and investigated its efficiency for the degradation of polybrominated diphenyl ethers (PBDEs). The plated Pd significantly enhances the degradation rate of PBDEs by ZVZ at the optimum loading of 1% by weight. In the Pd/ZVZ system, very few lower BDEs were accumulated during the degradation of 2,2',4,4'- tetrabromodiphenyl ether (BDE-47) and the final product is diphenyl ether, whereas the ZVZ system only debrominates BDE-47 to di-BDE and further debromination becomes very difficult. The degradation rates of BDEs by ZVZ greatly decreased with decreased bromination level, while in Pd/ZVZ system, the degradation rates of PBDEs did not show a significant difference. These indicate different mechanisms. This was confirmed by investigating the debromination pathways of the PBDEs in both systems. We determined that a H-transfer was the dominant mechanism in the Pd/ZVZ system. In addition, the reactivity of Pd/ZVZ to BDE-47 is pH-independent, which has a great advantage for various applications over ZVZ alone. Our study provides a new approach for the remediation of the PBDEs pollution.
我们合成了一种新型材料，即钯负载零价锌（Pd/ZVZ），并研究了其对多溴二苯醚（PBDEs）降解的效率。在最佳负载量为 1%（重量比）时，负载的 Pd 显著提高了 ZVZ 对 PBDEs 的降解速率。在 Pd/ZVZ 体系中，在 2,2',4,4'-四溴二苯醚（BDE-47）的降解过程中，很少有较低 BDEs 积累，最终产物是二苯醚，而 ZVZ 体系仅将 BDE-47 脱溴化为二溴二苯醚，进一步脱溴变得非常困难。ZVZ 体系中 BDEs 的降解速率随溴化程度的降低而大大降低，而在 Pd/ZVZ 体系中，PBDEs 的降解速率没有明显差异。这表明存在不同的机制。通过研究两种体系中 PBDEs 的脱溴途径，我们证实了这一点。我们确定 H 转移是 Pd/ZVZ 体系中的主要机制。此外，Pd/ZVZ 对 BDE-47 的反应性与 pH 无关，这使其在各种应用中相对于单独的 ZVZ 具有很大的优势。我们的研究为 PBDEs 污染的修复提供了一种新方法。
