Enhancement of volatile fatty acid production by co-fermentation of food waste and excess sludge without pH control: The mechanism and microbial community analyses. (September 2016)

• Record Type: Journal Article
• Authors: Wu, Qing-Lian; Guo, Wan-Qian; Zheng, He-Shan; Luo, Hai-Chao; Feng, Xiao-Chi; Yin, Ren-Li; Ren, Nan-Qi
• Is Part Of: Bioresource technology. Volume 216(2016)
• Page Start: 653
• Page End: 660
• Publication Date: 2016-09
• Subjects: Co-fermentation -- Food waste -- Excess sludge -- Volatile fatty acid -- Microbial community -- DOM; 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.2016.06.006
• Languages: English
• ISSNs: 0960-8524

Abstract

Highlights: The high VFA production was obtained the first time without pH control. Variations of DOM were quantitatively assessed by EEM and FRI technique. Co-fermentation effectively enhanced hydrolysis yield and acidogenesis yield. pH was self-maintained at beneficial range of 5.2–6.4 for VFA accumulation. Co-fermentation raised hydrolytic/acidogenic bacteria while inhibited methanogens. Abstract: The study provided a cost-effective and high-efficiency volatile fatty acid (VFA) production strategy by co-fermentation of food waste (FW) and excess sludge (ES) without artificial pH control. VFA production of 867.42 mg COD/g-VS was obtained under the optimized condition: FW/ES 5, solid retention time 7 d, organic loading rate 9 g VS/L-d and temperature 40 °C. Mechanism exploration revealed that the holistic biodegradability of substrate was greatly enhanced, and proper pH range (5.2–6.4) was formed by the high buffering capacity of the co-fermentation system itself, which effectively enhanced hydrolysis yield (63.04%) and acidification yield (83.46%) and inhibited methanogenesis. Moreover, microbial community analysis manifested that co-fermentation raised the relative abundances of hydrolytic and acidogenic bacteria including Clostridium, Sporanaerobacter, Tissierella and Bacillus, but suppressed the methanogen Anaerolineae, which also facilitated high VFA production. These results were of great guiding significance aiming for VFA recovery from FW and ES in large-scale.