Comparison of solid-state anaerobic digestion and composting of yard trimmings with effluent from liquid anaerobic digestion

Bioresour Technol. 2014 Oct:169:439-446. doi: 10.1016/j.biortech.2014.07.007. Epub 2014 Jul 9.

Abstract

Solid-state anaerobic digestion (SS-AD) and composting of yard trimmings with effluent from liquid AD were compared under thermophilic condition. Total solids (TS) contents of 22%, 25%, and 30% were studied for SS-AD, and 35%, 45%, and 55% for composting. Feedstock/effluent (F/E) ratios of 2, 3, 4, 5, and 6 were tested. In composting, the greatest carbon loss was obtained at 35% TS, which was 2-3 times of that at 55% TS and was up to 50% higher than that in SS-AD. In SS-AD, over half of the degraded carbon was converted to methane with the greatest methane yield of 121 L/kg VS(feedstock). Methane production from SS-AD was low at F/E ratios of 2 and 3, likely due to the inhibitory effect of high concentrations of ammonia nitrogen (up to 5.6g/kg). The N-P-K values were similar for SS-AD digestate and compost with different dominant nitrogen forms.

Keywords: Biogas; Carbon loss; Composting; Solid-state anaerobic digestion; Thermophilic.

Publication types

  • Comparative Study
  • Research Support, U.S. Gov't, Non-P.H.S.

MeSH terms

  • Ammonia / analysis
  • Anaerobiosis
  • Bioreactors / microbiology
  • Carbon Dioxide / analysis
  • Fatty Acids, Volatile / analysis
  • Hydrogen-Ion Concentration
  • Methane / analysis
  • Nitrogen / analysis
  • Organic Chemicals / isolation & purification
  • Plant Leaves / chemistry*
  • Refuse Disposal / methods*
  • Soil / chemistry*
  • Temperature
  • Waste Disposal, Fluid*

Substances

  • Fatty Acids, Volatile
  • Organic Chemicals
  • Soil
  • Carbon Dioxide
  • Ammonia
  • Nitrogen
  • Methane