Comparison of decabromodiphenyl ether degradation in long-term operated anaerobic bioreactors under thermophilic and mesophilic conditions and the pathways involved

Anaerobic digestion of decabromodiphenyl ether was carried out and compared in two continuously stirred anaerobic bioreactors for 210 days under thermophilic and mesophilic conditions. Results show that the degradation of decabromodiphenyl ether followed the first-order reaction kinetics, which exhibited a higher removal rate in the thermophilic reactor when compared to the mesophilic one, reaching its maximum of 1.1 mu g.day-1. The anaerobic digestion of decabromodiphenyl ether was found to involve the replacement of bromines from polybrominated diphenyl ether by hydrogen atoms, gradually forming nona-, octa- and heptabrominated diphenyl ether, respectively. Under the thermophilic condition, the reactors were dominated by Bacillus sp. and Methanosarcina sp. with high bioactivity and high concentrations of debromination microorganisms.

Automated summary

Decabromodiphenyl ether was anaerobically digested in two continuously stirred anaerobic bioreactors under thermophilic and mesophilic conditions for 210 days. The degradation followed first-order reaction kinetics, with a higher removal rate in the thermophilic reactor. Dominant species in the thermophilic reactor were Bacillus sp. and Methanosarcina sp. with high bioactivity and concentrations of debromination microorganisms.