Back to Search Start Over

Temperature-phased anaerobic co-digestion of food waste and paper waste with and without recirculation: Biogas production and microbial structure.

Authors :
Li L
Kong Z
Qin Y
Wu J
Zhu A
Xiao B
Ni J
Kubota K
Li YY
Source :
The Science of the total environment [Sci Total Environ] 2020 Jul 01; Vol. 724, pp. 138168. Date of Electronic Publication: 2020 Mar 24.
Publication Year :
2020

Abstract

Two temperature-phased anaerobic digestion (TPAD) systems (55 °C in the first reactor and 35 °C in the second reactor) with and without recirculation were operated in parallel for the co-digestion of food waste and paper waste. A long-term experiment was carried out for these two systems with the paper waste ratios elevated from 0 to 50%. The removal efficiencies of COD, TS, VS, carbohydrate and protein in the recirculated TPAD system were higher than those of the non-recirculated system. The successful acclimation of thermophilic cellulose-degrading bacteria in the first reactor (RT1), partly due to recirculation, ensured the effective degradation of cellulose when the paper waste ratio was higher than 40%, resulting in the production of large amounts of hydrogen in reactor RT1. In the absence of recirculation, the main substance produced in the first reactor of the non-recirculated system (T1) was lactic acid. This gradually led to over-acidification and a low degradation efficiency and no methane or hydrogen was produced in T1. Recirculation helped to establish a stable bacterial community capable of producing bio-hydrogen in reactor RT1. The relatively low pH of 5.5 in the RT1 inhibited the activity of hydrogenotrophic archaea without consuming hydrogen, facilitating high hydrogen production levels.<br />Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.<br /> (Copyright © 2020 Elsevier B.V. All rights reserved.)

Details

Language :
English
ISSN :
1879-1026
Volume :
724
Database :
MEDLINE
Journal :
The Science of the total environment
Publication Type :
Academic Journal
Accession number :
32247142
Full Text :
https://doi.org/10.1016/j.scitotenv.2020.138168