Abstract

The effects of ammonia on semicontinuous anaerobic digestion (AD) of food waste were studied. Inhibition effects were observed when the total ammonium concentration in the AD reactor exceeded 2g/L. Ammonia strongly inhibited methanogenesis but minimally affected hydrolysis and acidification. Inhibition of AD by ammonia enhanced the accumulation of acetate and propionate and consequently decreased the pH, which worsened the inhibition effects. With increasing ammonium concentration, methane production from acetate shifted from acetoclastic methanogenesis (mostly by Methanosaeta) to syntrophic acetate oxidation coupled with hydrogenotrophic methanogenesis (mostly by Methanosarcina). The metabolism of hydrogenotrophic methanogens Methanobacterium and Methanospirillum were inhibited when the ammonium concentration further increased to about 6 g/L. Microorganisms irrelevant in the methane fermentation process were enriched with the increase of ammonium concentration.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.