摘要

Tetrabromobisphenol A (TBBPA) is one of the most widely used brominated flame retardants and is ubiquitously present in the environment. In this study, we investigated the debromination of TBBPA by nanoscale zerovalent iron (nZVI) in methanol/water (50/50) solutions. Zerovalent iron nanoparticles demonstrated an excellent capacity to debrominate TBBPA to tribromobisphenol A, dibromobisphenol A, bromobisphenol A, and bisphenol A. More than 86% of TBBPA was debrominated within 16 h in a pH 7.5 reaction solution initially containing 3.0 g/L of nZVI. Debromination of TBBPA was apparently accompanied by the release of bromine ions and the elevation of solution pH. The debromination kinetics could be well-described by a three-parameter pseudo-first-order decay model. A higher loading of nZVI and acidic conditions facilitated the debromination process, while coexisting Ca2+ and Na+ species inhibited the reaction. On the basis of identified reaction intermediates and products, TBBPA debromination pathways by nZVI were proposed. This study suggests that nZVI may be potentially employed to debrominate TBBPA in soil and sediment.

全文