Salinity inhibition in thermophilic anaerobic digestion of organic waste

Zupančič, Gregor Drago (author), Panjicko, Mario (author), Marinšek-Logar, Romana (author), Lavrič, Lea (author), Zorec, Maša (author), Fanedl, Lijana (author)

Anaerobic digestion, despite its preferable use as a treatment for high organic matter polluted waste streams, is susceptible to inhibitors, salt included. Therefore, two different experiments were conducted to observe the responses of bacterial and archaeal communities to hypersaline environments. In the first experiment, salt was added gradually, while in the second experiment, salt was added rapidly (so-called salt shocks were performed). The results of the gradual addition of salt showed a recovery of methane production after the salt concentration decreased. The NaCl concentration of 28.2 g/L seems to be the limit between stable operation and occurrence inhibition. The specific biogas production varied between 0.490 and 0.562 m3/kgtCOD during the stepwise salt addition, depending on the salt concentration, while the maximal achieved COD removal was 79.8%. The results of the rapid salt addition showed good recovery of the bacterial community, while a reduction of salt-sensitive species was observed in the archaeal community. The trend of specific biogas production during rapid salt addition was stable with an average value of 0.590 m3/kgtCOD, and it was observed that higher concentrations of up to 39.4 g/L of NaCl were tolerated. The maximum COD removal achieved during rapid salt addition was 83.1%. In conclusion, certain bacterial and archaeal communities were well-adapted to the hypersaline environment and remained active during the anaerobic digestion of substrates with high salt concentration.

• Language: English
• Keywords: biogas, organic waste, microbial community structure, terminal restriction fragment length polymorphism, salinity inhibition, thermophilic, anaerobic digestion
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: BF - Biotechnical Faculty
• Publication status: Published
• Publication version: Version of Record
• Year: 2023
• Number of pages: 15 str.
• Numbering: Vol. 13, iss. 11, art. 6590
• PID: 20.500.12556/RUL-147076
• UDC: 579
• ISSN on article: 2076-3417
• DOI: 10.3390/app13116590
• COBISS.SI-ID: 153890051
• Publication date in RUL: 22.06.2023

Record is a part of a journal

• Title: Applied sciences
• Shortened title: Appl. sci.
• Publisher: MDPI
• ISSN: 2076-3417
• COBISS.SI-ID: 522979353

Licences

• License: CC BY 4.0, Creative Commons Attribution 4.0 International
• Link: http://creativecommons.org/licenses/by/4.0/
• Description: This is the standard Creative Commons license that gives others maximum freedom to do what they want with the work as long as they credit the author.

Secondary language

• Language: Slovenian
• Keywords: mikrobiologija, organski odpadki, bioplin, anaerobna razgradnja, slanost

Projects

• Funder: Other - Other funder or multiple funders
• Funding programme: Slovenian Technology Agency, Project SRRP TIA
• Project number: P-SRRP-09/II/90