The effect of trace element addition to mono-digestion of grass silage at high organic loading rates

Bioresour Technol. 2014 Nov:172:349-355. doi: 10.1016/j.biortech.2014.09.066. Epub 2014 Sep 20.

Abstract

This study investigated the effect of trace element addition to mono-digestion of grass silage at high organic loading rates. Two continuous reactors were compared. The first mono-digested grass silage whilst the second operated in co-digestion, 80% grass silage with 20% dairy slurry (VS basis). The reactors were run for 65weeks with a further 5weeks taken for trace element supplementation for the mono-digestion of grass silage. The co-digestion reactor reported a higher biomethane efficiency (1.01) than mono-digestion (0.90) at an OLR of 4.0kgVSm(-3)d(-1) prior to addition of trace elements. Addition of cobalt, iron and nickel, led to an increase in the SMY in mono-digestion of grass silage by 12% to 404LCH4kg(-1)VS and attained a biomethane efficiency of 1.01.

Keywords: Biogas; Grass silage; Slurry; Trace elements.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacteria, Anaerobic / metabolism*
  • Bioreactors / microbiology*
  • Manure / microbiology
  • Methane / metabolism*
  • Poaceae / microbiology*
  • Refuse Disposal / methods
  • Silage / microbiology*
  • Trace Elements / metabolism*

Substances

  • Manure
  • Trace Elements
  • Methane