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Updated: Jul 4, 2026

Continuously-stirred Anaerobic Digester to Convert Organic Wastes into Biogas: System Setup and Basic Operation
Published on: July 13, 2012
In-situ intermittent micro-aeration in food waste and sewage sludge anaerobic co-digestion: Performance, stability,
Wachiranon Chuenchart1, Christelle Sawaya2, K C Surendra3
1Department of Molecular Biosciences and Bioengineering (MBBE), University of Hawai'i at Mānoa, USA; Department of Civil, Environmental and Construction Engineering (CECE), University of Hawai'i at Mānoa, USA; Quasar Energy Group, 2705 Selby Road, Wooster, OH 44691-4096, USA.
Abstract:
Anaerobic co-digestion (AcoD) of sewage sludge (SS) with food waste (FW) is a practical approach in urban areas due to spatio-temporal availability of these co-substrates. While micro-aeration could enhance hydrolysis and control acidification during mono-digestion, the effects of micro-aeration on AcoD remains unclear. This study explored the influence of oxidation-reduction potential (ORP)-based in-situ micro-aeration on AcoD performance of SS and FW. Although mono-digestion of FW failed due to acidification and micro-aeration of SS was unstable due to high solids content and viscosity, micro-aeration improved specific biogas and methane yields by 21.1 % and 13.1 %, respectively, at the FW:SS ratio of 60:40 ((volatile solids (VS) basis). This improvement was observed at an organic loading rate of 2.25 g VS/L·d and alkalinity below 5000 mg CaCO3/L. The observed positive effect of micro-aeration was accompanied by changes in relative abundance of Aminicenantes. Functional analysis suggested that AcoD was driven by homoacetogenesis and acetoclastic methanogenesis.
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