Tetrabromobisphenol-A (TBBPA) is a pollutant which has a devastating impact on our environment and should be removed from earth. This research aims to evaluate the aerobic and anaerobic TBBPA degradation and bacterial community changes in mangrove sediments. TBBPA degradation in the sediments was enhanced with a microcapsuled enzyme extract of spent mushroom compost (MC) under aerobic conditions and with zerovalent iron under anaerobic conditions. The TBBPA aerobic or anaerobic degradation rates were enhanced for three time additions. Four bacterial genera (Bacillus, Erythrobacter, Pseudomonas, Rhodococcus) were associated with TBBPA aerobic degradation; and four other bacterial genera (Desulfovibrio, Pseudomonas, Sphaerochaeta, Sphingomonas) were associated with TBBPA anaerobic degradation in the sediment. Moreover, nine methanogens were identified under anaerobic conditions that might also be involved in TBBPA anaerobic degradation in the sediment. Our results demonstrate two feasible methods toward TBBPA bioremediation for mangrove sediments under aerobic and anaerobic conditions.

This study evaluated decabromodiphenyl ether (BDE-209) anaerobic debromination and bacterial community changes in mangrove sediment. BDE-209 debromination rates were enhanced with zerovalent iron compared to without zerovalent iron in the sediment. BDE-209 debromination rates in microcosms constructed with sediments collected in autumn were higher than in microcosms constructed with sediments collected in spring and were higher at the Bali sampling site than the Guandu sampling site. The intermediate products resulting from the reductive debromination of BDE-209 in sediment were nona-BDE (BDE-206, BDE-207), octa-BDEs (BDE-196, BDE-197), hepta-BDEs (BDE-183, BDE-184, BDE-191), hexa-BDEs (BDE-137, BDE-138, BDE-154, BDE-157), penta-BDEs (BDE-85, BDE-99, BDE-100, BDE-126), tetra-BDEs (BDE-47, BDE-49, BDE-66, BDE-77), tri-BDEs (BDE-17, BDE-28), and di-BDEs (BDE-15). Fifty bacterial genera associated with BDE-209 debromination were identified. Overall, 12 of the 50 bacterial genera were reported to be involved in dehalogenation of aromatic compounds. These bacteria have high potential to be BDE-209 debromination bacteria. Different combinations of bacterial community composition exhibit different abilities for BDE-209 anaerobic debromination.