Sulfite Treatment Sludge Raw sequence reads. Sulfite Treatment Sludge

in-situ sulfite treatment in a side-stream bioreactor was proposed to enhance short-chain fatty acids (SCFAs) production from waste activated sludge (WAS) anaerobic fermentation. First, the production of SCFAs, especially acetic acid, was significantly increased in a shorter fermentation time. Mechanistic studies showed that sulfite could simultaneously accelerate and enhance hydrolysis and acidification processes while inhibiting methane production during WAS fermentation. Illumina Miseq sequencing analysis indicated that microbial and anaerobic microbial abundance associated with the production of SCFAs was stimulated, which would facilitate the biological process. Secondly, sulfite treatment inactivated pathogens in WAS, improved the dewatering properties of the sludge and enhanced the quality of the fermentation residue. The sludge after fermentation in the side-stream bioreactor is returned to the biochemical lagoons as an "internal carbon source" to reduce the external carbon input and to alleviate the competition for carbon sources. The in-situ sulfite treatment in a side-stream bioreactor is an important measure to enhance resource and energy recycling in wastewater plants and has great potential for development with economic and environmental value.