Lactic acid and methane: Improved exploitation of biowaste potential. (January 2015)

• Record Type: Journal Article
• Authors: Dreschke, G.; Probst, M.; Walter, A.; Pümpel, T.; Walde, J.; Insam, H.
• Is Part Of: Bioresource technology. Volume 176(2015)
• Page Start: 47
• Page End: 55
• Publication Date: 2015-01
• Subjects: BMP biomethane potential (Nml g−1 VS) -- +D/−D with dialysis/without dialysis -- LA, AA, PA, BA lactic acid acetic acid, propionic acid, butyric acid -- NGS next generation sequencing -- pH5 fermentation performed in batch mode with pH control to 5 -- pH∼ fermentation performed in batch mode without pH control -- S1 biowaste collected at a biowaste treatment plant in Pfaffenhofen, Austria -- S2 biowaste collected at a biowaste treatment plant in Innsbruck, Austria -- tpxx time point after xx h of fermentation -- VFA volatile fatty acids (only LA, AA, PA and BA were considered) -- VFAcumxx cumulative amount of VFA (LA, AA, PA and BA) produced until tp xx h (g kg−1) -- VFAiBxx current amount of VFA (LA, AA, PA and BA) in broth at tp xx h (g kg−1) -- VS volatile solids (g kg−1 fresh substrate) -- VS−LA amount of VS of co-substrate without LA (g); Fermentation -- Municipal organic solid waste -- Biogas potential -- Lactobacillus -- Waste treatment; Biomass -- Periodicals; Biomass energy -- Periodicals; Bioremediation -- Periodicals; Agricultural wastes -- Periodicals; Factory and trade waste -- Periodicals; Organic wastes -- Periodicals; Bioénergie -- Périodiques; Déchets agricoles -- Périodiques; Déchets industriels -- Périodiques; Déchets organiques -- Périodiques; Déchets (Combustible) -- Périodiques; 662.88
• DOI: 10.1016/j.biortech.2014.10.136
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: Municipal organic solid waste is suitable for lactic acid production. Lactic acid yield can be enhanced by lactic acid extraction during fermentation. Optimal fermentation period of 24 h for lactic acid production. Lactobacilli can be enriched to over 70% of the bacterial community. High biomethane potential of lactic acid fermentation residues. Abstract: This feasibility study investigated a two-step biorefining approach to increase the value gained by recycling of organic municipal solid waste. Firstly, lactic acid was produced via batch fermentation at 37 °C using the indigenous microbiome. Experiments revealed an optimal fermentation period of 24 h resulting in high yields of lactic acid (up to 37 g kg −1 ). The lactic acid proportion of total volatile fatty acid content reached up to 83%. Lactobacilli were selectively enriched to up to 75% of the bacterial community. Additionally conversion of organic matter to lactic acid was increased from 22% to 30% through counteracting end product inhibition by continuous lactic acid extraction. Secondly, fermentation residues were used as co-substrate in biomethane production yielding up to 618 ± 41 Nml biomethane g −1 volatile solids. Digestate, the only end product of this process can be used as organic fertilizer.