Combined effect of crude fat content and initial substrate concentration on batch anaerobic digestion characteristics of food waste

Bioresour Technol. 2017 May:232:304-312. doi: 10.1016/j.biortech.2017.02.039. Epub 2017 Feb 24.

Abstract

The mesophilic anaerobic digestion (AD) characteristics of food waste (FW) with different crude fat (CF) contents and four initial substrate concentrations (4, 6, 8, and 10gVS/L) were investigated. The maximum methane yields of FW with CF contents of 15%, 20%, 25%, 30%, and 35% were 565.0, 580.2, 606.0, 630.2 and 573.0mLCH4/gVSadded, respectively. An acidification trend with a drop in pH (<6.80) and increase in the volatile fatty acids/total inorganic carbon (VFAs/TIC) ratio (>0.4) were found for CF contents of 30% (10gVS/L) and 35% (8 and 10gVS/L). A 35% CF content in FW led to decrease in the first-order degradation constant of approximately by 40%. The modified Gompertz model showed that the lag phase (λ) was prolonged from 0.4 to 7.1days when the CF content in FW and initial substrate concentration were increased to 35% and 10gVS/L.

Keywords: Anaerobic digestion; Crude fat content; Food waste; Initial substrate concentration; Kinetic study.

MeSH terms

  • Anaerobiosis
  • Bioreactors*
  • Dietary Fats / pharmacology*
  • Fatty Acids, Volatile / chemistry
  • Food Industry / methods
  • Food*
  • Humans
  • Methane / metabolism
  • Models, Theoretical
  • Solid Waste*
  • Waste Management / methods

Substances

  • Dietary Fats
  • Fatty Acids, Volatile
  • Solid Waste
  • Methane