A syntrophic propionate-oxidizing microflora and its bioaugmentation on anaerobic wastewater treatment for enhancing methane production and COD removal

Abstract

Syntrophic propionate-oxidizing microflora B83 was enriched from anaerobic sludge.

The bioaugmentation of microflora B83 were evaluated from wastewater treatment.

Methane yield and COD removal were enhanced by bioaugmentation of microflora B83.

Hydrogen-producing acetogensis was a rate-limiting step in methane fermentation.

Methane fermentation process can be restricted and even destroyed by the accumulation of propionate because it is the most difficult to be anaerobically oxidized among the volatile fatty acids produced by acetogenesis. To enhance anaerobic wastewater treatment process for methane production and COD removal, a syntrophic propionate-oxidizing microflora B83 was obtained from an anaerobic activated sludge by enrichment with propionate. The inoculation of microflora B83, with a 1:9 ratio of bacteria number to that of the activated sludge, could enhance the methane production from glucose by 2.5 times. With the same inoculation dosage of the microflora B83, COD removal in organic wastewater treatment process was improved from 75.6% to 86.6%, while the specific methane production by COD removal was increased by 2.7 times. Hydrogen-producing acetogenesis appeared to be a rate-limiting step in methane fermentation, and the enhancement of hydrogen-producing acetogens in the anaerobic wastewater treatment process had improved not only the hydrogen-producing acetogenesis but also the acidogenesis and methanogenesis.

Graphical abstract

Keywords

Anaerobic wastewater treatment / Methane production / Hydrogen-producing acetogenesis / Methanogenesis / Rate-limiting step / Bioaugmentation

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Higher Education Press and Springer–Verlag Berlin Heidelberg