Fe(II)EDTA-NO reduction by a newly isolated thermophilic Anoxybacillus sp HA from a rotating drum biofilter for NOx removal

The reduction of Fe(II)EDTA-NO is one of the core processes in BioDeNOx, an integrated physicochemical and biological technique for NOx removal from industrial flue gases. A newly isolated thermophilic Anoxybacillus sp. HA, identified by 16S rRNA sequence analysis, could simultaneously reduce Fe(II)EDTA-NO and Fe(III)EDTA. A maximum NO removal efficiency of 98.7% was achieved when 3 mM Fe(II)EDTA-NO was used in the nutrient solution at 55 degrees C. Results of this study strongly indicated that the biological oxidation of Fe(II)EDTA played an important role in the formation of Fe (III)EDTA in the anaerobic system. Fe(II)EDTA-NO was more competitive than Fe(III)EDTA as an electron acceptor, and the presence of Fe(III)EDTA slightly affected the reduction rate of Fe(II) EDTA-NO. At 55 degrees C, the maximum microbial specific growth rate mu(max) reached the peak value of 0.022 h(-1). The maximum NO removal efficiency was also measured (95.4%) under this temperature. Anoxybacillus sp. HA, which grew well at 50 degrees C-60 degrees C, is a potential microbial resource for Fe(II)EDTA-NO reduction at thermophilic temperatures. (C) 2014 Elsevier B.V. All rights reserved.