exploring the microbial response to sulphate and ammonia
Moestedt, Jan
(2015).
Biogas production from thin stillage.
Diss. (sammanfattning/summary)
Uppsala :
Sveriges lantbruksuniv.,
Acta Universitatis Agriculturae Sueciae, 1652-6880
; 2015:10
ISBN 978-91-576-8218-5
eISBN 978-91-576-8219-2
[Doctoral thesis]
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Abstract
The biogas plant in Norrköping (Tekniska verken i Linköping AB, publ.), Sweden, operates with thin stillage, a residue from bio-ethanol fermentation, as the main feedstock. Thin stillage is energy-rich due to its high protein content, but due to its high nitrogen and sulphate content is a somewhat complicated feedstock. The high nitrogen concentration results in inhibition of the microbial process and also selects for nitrogen-tolerant, but slow-growing, syntrophic acetate-oxidising bacteria (SAOB). The high sulphate concentration in the feedstock results in production of toxic and inhibitory sulphides through the activity of sulphate-reducing bacteria (SRB). Measures currently applied at Norrköping biogas plant to optimise the degradation of thin stillage include: i) use of mesophilic temperature and addition of hydrochloric acid, ii) use of long hydraulic retention time and iii) addition of iron and trace elements.
This thesis investigated how to obtain a more efficient biogas process treating thin stillage, with Norrköping biogas plant as the model plant. It also explored the role of SRB in the anaerobic process at high nitrogen content and sought to identify optimal conditions for ammonia-tolerant methane-producing microorganisms. This was done by measuring SRB abundance in several large-scale biogas processes to identify conditions resulting in reduced numbers. In parallel, the effects of increasing temperature and organic load, calcium addition and a two-stage strategy were evaluated in laboratory studies. The results showed a correlation between high ammonia level and temperature with decreased abundance of SRB, but none of the operating strategies tested proved successful in repressing sulphate reduction. However, increasing ammonia and/or organic loading rate influenced both the acetogenic and methanogenic community, including potential SAOB. Moreover, increasing the temperature to 44 ºC resulted in increased abundance of thermotolerant SAOB and their partner methanogen and higher biogas yield (+22%). A maximum ammonia threshold concentration of approximately 1.1 g L-1 was identified.
Application of the findings reported in this thesis has resulted in increased process stability in biogas plants in Sweden.
Authors/Creators: | Moestedt, Jan | ||||||||||||
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Title: | Biogas production from thin stillage | ||||||||||||
Subtitle: | exploring the microbial response to sulphate and ammonia | ||||||||||||
Series Name/Journal: | Acta Universitatis Agriculturae Sueciae | ||||||||||||
Year of publishing : | 2015 | ||||||||||||
Depositing date: | 20 January 2015 | ||||||||||||
Number: | 2015:10 | ||||||||||||
Number of Pages: | 58 | ||||||||||||
Papers/manuscripts: |
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Place of Publication: | Uppsala | ||||||||||||
Publisher: | Department of Microbiology, Swedish University of Agricultural Sciences | ||||||||||||
ISBN for printed version: | 978-91-576-8218-5 | ||||||||||||
ISBN for electronic version: | 978-91-576-8219-2 | ||||||||||||
ISSN: | 1652-6880 | ||||||||||||
Language: | English | ||||||||||||
Publication Type: | Doctoral thesis | ||||||||||||
Full Text Status: | Public | ||||||||||||
Agris subject categories.: | P Natural resources > P06 Renewable energy resources P Natural resources > P10 Water resources and management Q Food science > Q70 Processing of agricultural wastes | ||||||||||||
Subjects: | (A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Biochemistry and Molecular Biology (A) Swedish standard research categories 2011 > 1 Natural sciences > 106 Biological Sciences (Medical to be 3 and Agricultural to be 4) > Microbiology (Microbiology in the medical area to be 30109) (A) Swedish standard research categories 2011 > 2 Engineering and Technology > 209 Industrial Biotechnology > Bioprocess Technology (A) Swedish standard research categories 2011 > 2 Engineering and Technology > 209 Industrial Biotechnology > Bioenergy | ||||||||||||
Agrovoc terms: | biogas, brewery byproducts, wastewater treatment, anaerobic digestion, sulphate, sulphides, bacteria, methanogens, reduction | ||||||||||||
Keywords: | anaerobic digestion, biogas, sulphate, sulphate-reducing bacteria, acetogens, methanogens, syntrophic acetate-oxidising bacteria, hydrogen sulphide, thin stillage, ammonia inhibition | ||||||||||||
URN:NBN: | urn:nbn:se:slu:epsilon-e-2315 | ||||||||||||
Permanent URL: | http://urn.kb.se/resolve?urn=urn:nbn:se:slu:epsilon-e-2315 | ||||||||||||
ID Code: | 11751 | ||||||||||||
Faculty: | NJ - Fakulteten för naturresurser och jordbruksvetenskap | ||||||||||||
Department: | (NL, NJ) > Dept. of Microbiology (until 161231) | ||||||||||||
External funders: | FORMAS | ||||||||||||
Deposited By: | Jan Moestedt | ||||||||||||
Deposited On: | 21 Jan 2015 10:41 | ||||||||||||
Metadata Last Modified: | 10 Sep 2020 13:41 |
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