Abstract：
Effective removal of polybrominated diphenyl ethers (PBDEs) from the environment is essential for the ecosystem and human health. Reductive debromination of PBDEs by nanoscale zerovalent iron (nZVI) has become an important technology. However, the agglomeration and low persistence catalytic activity of nZVI particles have become urgent problems to be improved. Herein, we report the first application of a new organo-attapulgite (OA) supported Fe/Pd nanoparticles (OA-Fe/Pd) composite for decabromodiphenyl ether (BDE209) removal. BDE209 was efficiently removed using OA-Fe/Pd with a reaction rate that was 9.97 times greater than that of the nZVI due to the synergetic effect of support material OA and Pd loading. OA could prevent nZVI particles from agglomeration and adsorb BDE209 molecules to its surface. Pd could supply atomic hydrogen and also prevent the oxidation of nZVI particles. The degradation of BDE209 by OA-Fe/Pd was affected by many factors and followed pseudo first-order kinetics. The degradation of BDE209 by OA-Fe/Pd underwent a stepwise debromination manner with the H-transfer dominant mechanism. BDE209 (25 mg∙L-1) could be degraded to penta-BDEs to diphenyl ether (DE) by 3.0 g∙L-1 OA-Fe/Pd within 240 min under neutral condition. This study provides some inspiration for improving the removal efficiency of PBDEs with nZVI-based materials.
摘要：
从环境中有效去除多溴联苯醚(PBDEs)对生态系统和人类健康至关重要。纳米零价铁(nZVI)对多溴二苯醚的还原脱溴已成为一项重要技术。然而,nZVI颗粒的团聚和低持久性催化活性已成为亟待解决的问题。在这里，我们报道了一种新的有机凹凸棒石（OA）负载的Fe/Pd纳米颗粒（OA-Fe/Pd）复合材料在十溴二苯醚（BDE209）去除中的首次应用。由于载体材料OA和Pd负载的协同作用,使用OA-Fe/Pd以大于nZVI的9.97倍的反应速率有效地除去BDE209。OA可以防止nZVI颗粒聚集并将BDE209分子吸附到其表面。Pd可以提供原子氢并且还防止nZVI颗粒的氧化。OA-Fe/Pd对BDE209的降解受多种因素的影响，并遵循拟一级动力学。OA-Fe/Pd对BDE209的降解经历了具有H转移主导机制的逐步脱溴方式。在中性条件下，BDE209（25mg•L-1）可以在240分钟内通过3.0g•L-1OA-Fe/Pd降解为五溴二苯醚（DE）。本研究为提高nZVI基材料对多溴二苯醚的去除效率提供了一定的启示。
