Zheng S, Yang F, Huang W, Lei Z, Zhang Z, Huang W. Combined effect of zero valent iron and magnetite on
semi-dry anaerobic digestion of swine manure.
Bioresour Technol 2022;
346:126438. [PMID:
34852281 DOI:
10.1016/j.biortech.2021.126438]
[Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Revised: 11/21/2021] [Accepted: 11/24/2021] [Indexed: 06/13/2023]
Abstract
Combined effect of zero valent iron (ZVI) and magnetite on semi-dry anaerobic digestion of swine manure was studied. Compared with control, the addition of 5 g/L ZVI, magnetite and their mixture (1:1 wt) increased the CH4 yield by 17.6%, 22.7% and 21.9%, respectively. The three additives improved CH4 production through altering the metabolism pathways, rather than improving the solid degradation efficiency. ZVI promoted interspecies hydrogen transfer (IHT) by enriching H2-comsuming Methanolinea and acetate-oxidizing bacteria (Sedimentibacter and Clostridium). Magnetite enriched dissimilatory iron reduction bacteria (Acinetobacter) to accelerate organic hydrolysis and established direct interspecies electron transfer (DIET) by enriching Methanothrix and Methanospirillum. Key microorganisms relative to IHT (Clostridium) and DIET (Methanothrix and Methanospirillum) were simultaneously enriched with ZVI + magnetite, but they only showed an additive effect on methanogenesis, the lack of synergetic effect was attributable to the possible trade-off between IHT and DIET, or the little improvement effect of additives on substrate biodegradability.
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