Enhancing volatile fatty acid production in batch test reactors by modulating microbial communities with potassium permanganate.

The shift from conventional wastewater treatment plants to biorefineries is one of the most environmentally and economically sustainable pathways for extracting valuable compounds from waste. Besides chemical-physical processes, microorganisms within sewage sludge utilize organic and inorganic pollutants in the wastewater as nutrients, leading to effective water purification. However, the remaining solid sludge residue, typically destined for specific landfills or incineration, could undergo microbial fermentation to produce volatile fatty acids (VFA), metabolic precursors for biopolymers. Increasing attention has been directed towards optimizing operational parameters to enhance VFA production during sewage sludge fermentation. This study examined the impact of potassium permanganate (PP) on microbial communities during the sewage sludge's acidogenic fermentation. The results highlighted the positive effect of PP treatment, which increased COD production and VFA yield up to 1263.5 mg/L and 664.2 mg COD/L, respectively. The presence of PP significantly enhances VFA yield promoting bacteria positively linked to VFA production. • Bacterial fermentation of solid sludge residue from WWTP presents an opportunity to produce volatile fatty acids (VFA). • Potassium permanganate (KMnO₄) addition enhanced the VFA share up to 55 % of sCOD. • Macellibacteroides fermentans , Pseudomonas veronii and Proteocatella sphenisci increased in sludge treated with KMnO₄. • The addition of KMnO₄ in sewage sludge fermentation is a promising strategy for enhancing VFA yield by modulating bacterial communities. [ABSTRACT FROM AUTHOR]