Use of microaerobic conditions for the improvement of anaerobic digestion of solid wastes

Abstract

The treatment of solid wastes containing slowly biodegradable compounds or high level of sulphur compounds was carried out. In both cases the application of microaerobic conditions (that means controlled dosing of small amount of air or oxygen into digester) was an efficient tool to increase the biodegradability of treated material and/or to increase the activity of methanogenic bacteria by removal of their inhibitor.

The Influence of Micro-Oxygen Addition on Desulfurization Performance and Microbial Communities during Waste-Activated Sludge Digestion in a Rusty Scrap Iron-Loaded Anaerobic Digester

“…In P7, the COD removal and methane yield declined simultaneously due to system reductive environment destruction ( Figure 2). As noted above, these results are consistent with those reported in literature, even on an industrial scale, it has been broadly demonstrated that the presence of limited amounts (not exceeding 15 mL in this study) of O2 in digesters does not negatively affect digestion performance [38,39].…”

Electrolysis-enhanced anaerobic digestion of wastewater

“…The low current density led to limited oxygen formation, creating micro-aerobic conditions, which did not prevent methane production. Since the biomass granules in the UASB reactors are typically larger than 500 lm in diameter and the oxygen penetration depth does not exceed 50 lm( Quarmby and Forster, 1995;Thaveesri et al, 1995), the electrolytic oxygen might be consumed in the outer biofilm layer (Botheju et al, 2009;Jenicek et al, 2008;Jenicek et al, 2010;Kato et al, 1997;Shen and Guiot, 1996;Tan et al, 1999;Tartakovsky et al, 2006;Zhou et al, 2007).…”

“…at very low dissolved oxygen concentrations (Jagadabhi et al, 2010;Jenicek et al, 2008Jenicek et al, , 2010Shen and Guiot, 1996;Zitomer and Shrout, 1998). This improvement was attributed to the enhanced hydrolysis of complex organic matter (Botheju et al, 2009;Johansen and Bakke, 2006;Zhu et al, 2009).…”

“…This improvement was attributed to the enhanced hydrolysis of complex organic matter (Botheju et al, 2009;Johansen and Bakke, 2006;Zhu et al, 2009). The microaerobic environment can be created by limited reactor aeration (Jenicek et al, 2008;Johansen and Bakke, 2006;Pirt and Lee, 1983;Shen and Guiot, 1996;Zhou et al, 2007;Zitomer and Shrout, 1998) as well as by feeding small amounts of H 2 O 2 to the reactor (Tartakovsky et al, 2003).…”

Anaerobic Digestion of Wastewater With High Sulfate Concentration Using Micro-Aeration and Natural Zeolites

“…Several biological methods have been studied for sulfide removal from the aqueous phase in anaerobic digesters, but in the last 8 years research on microaerobic anaerobic processes has increased significantly (van der Zee et al, 2007;Jenicek et al, 2008). This is based on the use of microorganisms capable of oxidizing hydrogen sulfide to elemental sulfur, which becomes the main process byproduct.…”