High-brominated PBDE congeners are degraded via a
reductive debromination process, and their degradation
rates are higher than that for low-brominated PBDEs.12 The
observation in this study is consistent with our previous
finding that the anaerobic degradation rates of PBDE congeners
in sediment were in the order of BDE-209 > BDE-
99 > BDE-47 > BDE-28 > BDE-15.6 The addition of zerovalent
iron could reduce PBDEs to less-brominated compounds
by anaerobic microbes.13 Also, sorption could play a
role in the BDE-209 anaerobic degradation with the addition
of zero-valent iron.