56 / 2021-06-30 09:24:35

Enhancements of short-chain fatty acids production via anaerobic fermentation of waste activated sludge by the combined use of persulphate and micron-sized magnetite

Anaerobic fermentation; short chain fatty acids; micron-sized magnetite; persulphate; microbial community; biochemical metabolic function.

The performance of short chain fatty acids (SCFAs) production from waste activated sludge via anaerobic fermentation (AF) by combining persulphate (PDS) with micron-sized magnetite (Fe₃O₄) is investigated for the first time. The maximum yield of SCFAs was achieved on day 8 of AF with the introduction of Fe₃O₄ at 0.3 g/g SS when the PDS concentration kept at 0.5 g/g SS, which was approximately 2.39-folds than that in its counterpart. Both of the intracellular and extracellular substances were released into the aqueous phase, which provided abundant organic substrates for SCFAs production and enhanced key hydrolases activities simultaneously. The typical hydrolytic and acidifying microbial population (i.e. Actinobacteria) were also significantly enriched from 8.84% to 35.76%. In addition, key metabolic capacity (i.e. carbohydrate, amino acid, and energy metabolism) and enzymes have been demonstrated to be related with the hydrolysis of organic matters and the formation of acetic acid and butyric acid were also accelerated evidently on the basis of microbial functional analysis, leading to higher SCFAs productions.