Reductive debromination of decabromodiphenyl ether by anaerobic microbes from river sediment

Polybrominated diphenyl ethers (PBDEs) are emerging persistent organic pollutants and have consequently drawn much environmental concern. The objective of this study was to evaluate reductive debromination of decabromodiphenyl ether (BDE-209) by anaerobic microbes from river sediment under various conditions. The debromination rates for BDE-209 were enhanced by the addition of brij 30, brij 35, rhamnolipid, surfactin, vitamin B-12, zero-valent iron, acetate, lactate, and pyruvate. Zero-valent iron yielded the highest BDE-209 debromination. For the various PBDE congeners, the high-to-low order of debromination rates in sediment was BDE-209 > BDE-99 > BDE-47 > BDE-28 > BDE-15. The intermediate products resulting from the reductive debromination of BDE-209 in sediment were nona-BDE (BDE-207), octa-BDEs (BDE-196, 197), hepta-BDEs (BDE-183, 184, 191), hexa-BDEs (BDE-138, 154), penta-BDEs (BDE-85, 99, 100, 119), tetra-BDEs (BDE-47, 49, 66, 71), tri-BDEs (BDE-17, 28), di-BDEs (BDE-7, 15), and mono-BDE (BDE-3). Our result shows BDE-209 can be debrominated successively to BDE-3 by anaerobic microbes from river sediment. This research offers feasible methods for removal of BDE-209 in river sediment for bioremediation. (C) 2013 Elsevier Ltd. All rights reserved.