Improving production of volatile fatty acids from food waste fermentation by hydrothermal pretreatment

Bioresour Technol. 2014 Nov:171:323-9. doi: 10.1016/j.biortech.2014.08.062. Epub 2014 Aug 28.

Abstract

Food waste (FW) was pretreated by a hydrothermal method and then fermented for volatile fatty acid (VFAs) production. The soluble substance in FW increased after hydrothermal pretreatment (⩽200 °C). Higher hydrothermal temperature would lead to mineralization of the organic compounds. The optimal temperature for organic dissolution was 180 °C, at which FW dissolved 42.5% more soluble chemical oxygen demand than the control. VFA production from pretreated FW fermentation was significantly enhanced compared with the control. The optimal hydrothermal temperature was 160 °C with a VFA yield of 0.908 g/g VSremoval. Butyrate and acetate were the prevalent VFAs followed by propionate and valerate. FW fermentation was inhibited after 200 °C pretreatment. The VFAs were extracted from the fermentation broth by liquid-liquid extraction. The VFA recovery was 50-70%. Thus, 0.294-0.411 g VFAs could be obtained per gram of hydrothermally pretreated FW (in dry weight) by this method.

Keywords: Fermentation; Food waste; Hydrothermal pretreatment; VFAs extraction; Volatile fatty acids.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acetates / analysis
  • Biological Oxygen Demand Analysis
  • Bioreactors*
  • Butyrates / analysis
  • Fatty Acids, Volatile / biosynthesis*
  • Fermentation
  • Food*
  • Hot Temperature*
  • Liquid-Liquid Extraction
  • Waste Products*
  • Water / chemistry*

Substances

  • Acetates
  • Butyrates
  • Fatty Acids, Volatile
  • Waste Products
  • Water