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Indexed by:期刊论文

Date of Publication:2013-04-15

Journal:BIOCHEMICAL ENGINEERING JOURNAL

Included Journals:SCIE、EI

Volume:73

Page Number:80-85

ISSN No.:1369-703X

Key Words:Propionate; Fe-0; Acetate; Acetogenesis; Homoacetogenesis; Anaerobic

Abstract:Propionate is an unfavorable substrate for the anaerobic digestion because it is thermodynamically difficult to be decomposed into acetate. An attempt to enhance the decomposition of propionate by adding Fe-0 powder (log) into an acidogenic reactor (A1) with propionate as the sole carbon source was made in this study. The results showed that the propionate conversion rate (67-89%) in A1 were higher than that in a reference reactor (43-77%) without dosing of Fe-0 (A2). The enhanced conversion of propionate caused both chemical oxygen demand removal (COD) (57-79%) and acetate production (178-328 mg/L) in A1 to increase significantly. Although Fe-0 contributed the H-2 production chemically, the H-2 content of A1 was less than that of A2. The reason was ascribed to the enhanced utilization of H-2 for the homoacetogenesis. It was calculated that the Gibbs free energy in the decomposition of propionate was decreased by about 8.0-10.2% with the dosing of Fe-0. Also, the activities of enzymes related to the acetogenesis were enhanced by 2-34-folds. Fluorescence in situ hybridization (FISH) and denaturing gradient gel electrophoresis (DGGE) analysis indicated that Fe-0 increased the abundance of microbial communities, especially propionate-utilizing bacteria and homoacetogenic bacteria. (C) 2013 Elsevier B.V. All rights reserved.