Microbial dynamics and methanogenic potential of co-digestion of sugarcane vinasse and dairy secondary effluent in an upflow anaerobic sludge blanket reactor

• Published in: Bioresource technology Vol. 361; p. 127654
• Main Authors: Siqueira, Juliano Curi de, Assemany, Paula, Siniscalchi, Luciene Alves Batista
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01-10-2022
• Subjects: Agro-industrial wastewater; Anaerobic microorganisms; Biogas; High-rate anaerobic reactor; Next-generation sequencing; Anaerobic microorganisms; Biogas; Next-generation sequencing; High-rate anaerobic reactor; Agro-industrial wastewater
• ISSN: 0960-8524; 1873-2976
• DOI: 10.1016/j.biortech.2022.127654

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•The proposed co-digestion reached maximum CH4 yield of 308 mLCH4 gCODrem-1.•Next-generation sequencing showed a predominance of hydrogenotrophic methanogens.•The evaluated treatment system provided organic matter removals of up to 81%.•Co-digestion can be a straightforward and efficient strategy for vinasse biodigestion.
Co-digestion is a strategy that may prevent microbial inhibition during the anaerobic treatment of sugarcane vinasse, a substrate with highly biodegradable organic load, acidity, and toxic compound levels (e.g., sulfates, phenols). In this context, this study evaluated the microbial dynamics and methanogenic potential throughout the co-digestion of sugarcane vinasse and secondary effluent from the dairy industry in a mesophilic lab-scale upflow anaerobic sludge blanket (UASB) reactor. Periodic next-generation sequencing (NGS) analyses revealed an increase in the relative abundance of the phylum Euryarchaeota (+8.6 % after inoculation), predominating hydrogenotrophic methanogens (Methanobacterium and Methanobrevibacter) at the end of the operation. Moreover, the average methane yield was 221 mLCH4 gCODrem-1, with 69 % of organic matter removal. These results evidenced a progressive acclimation of the anaerobic microbial community to the substrate and a stable operation. Therefore, the proposed experiment demonstrates energy advantages for the agro-industrial sector by implementing a similar but full-scale treatment plant.