Abstract:Polybrominated diphenyl ethers (PBDEs) are efficient brominated flame retardants, which have been used extensively over recent three decades in various industrial and consumer products. PBDEs have been detected frequently in air, water, soil, sediment, and have attracted increasing attention in recent years because of their increasing levels in animal and human tissues, which can potentially pose serious adverse effects to the environmental safety and human health. Attapulgite- supported Fe/Ni bimetallic nanoparticles (A-Fe/Ni) were prepared to degrade the 2,2′,4,4′-tetrabromodiphenyl ether (BDE47) in this study. The effects of different dissolved organic matters (DOM) on the degradation of BDE47 in contaminated yellow brown soil-water/methanol solutions were investigated through debromination tests under anoxic conditions. A-Fe/Ni could degrade BDE47 effectively in contaminated yellow brown soil-methanol/water solutions, and the degradation process could be well described by the pseudo-second-order kinetics. BDE47 could be degraded into mono- to tri-BDEs and diphenyl ether (DE) by A-Fe/Ni. When the three different DOMs (humic acid, citric acid, and oxalic acid) were added in yellow brown soil-water/methanol solutions, the uptake of DOM on the Fe/Ni particles surface could form a mass and electron transfer barrier that retard the contact and reaction between BDE47 and the reactive sites of nanoparticles. The presence of DOM could obviously decrease the BDE47 degradation efficiency and also affect the profile changes of byproducts formation. The experimental results can provide scientific proofs on the PBDEs contaminated soil remediation using nanoscale zerovalent iron and Fe based bimetallic materials.