Acidogenic fermentation of the organic fraction of municipal solid waste and cheese whey for bio-plastic precursors recovery – Effects of process conditions during batch tests. (December 2017) - Girotto, Francesca
Highlights: Through AF, organic waste can be valorised to obtain bio-plastic precursors. Effects of nine combinations of substrate to inoculum ratio and pH were investigated. The main metabolites deriving from FW fermentation were butyrate and acetate. The main metabolite deriving from CW fermentation was lactate mainly influenced by pH. S/I ratio and pH significantly influence AF of FW and CW, respectively. Abstract: The problem of fossil fuels dependency is being addressed through sustainable bio-fuels and bio-products production worldwide. At the base of this bio-based economy there is the efficient use of biomass as non-virgin feedstock. Through acidogenic fermentation, organic waste can be valorised in order to obtain several precursors to be used for bio-plastic production. Some investigations have been done but there is still a lack of knowledge that must be filled before moving to effective full scale plants. Acidogenic fermentation batch tests were performed using food waste (FW) and cheese whey (CW) as substrates. Effects of nine different combinations of substrate to inoculum (S/I) ratio (2, 4, and 6) and initial pH (5, 7, and 9) were investigated for metabolites (acetate, butyrate, propionate, valerate, lactate, and ethanol) productions. Results showed that the most abundant metabolites deriving from FW fermentation were butyrate and acetate, mainly influenced by the S/I ratio (acetate and butyrate maximum productions of 21.4 and 34.5 g/L, respectively, at S/I = 6). Instead, when dealing with CW, lactate was the dominant metabolite significantly correlated with pH (lactate maximum production of 15.7 g/L at pH = 9).