Effects of feedstock ratio and organic loading rate on the anaerobic mesophilic co-digestion of rice straw and pig manure

Bioresour Technol. 2015:187:120-127. doi: 10.1016/j.biortech.2015.03.040. Epub 2015 Mar 13.

Abstract

In order to investigate the effects of feedstock ratio and organic loading rate (OLR) on the anaerobic mesophilic co-digestion of rice straw (RS) and pig manure (PM), batch bottle tests (2.5L) were carried out at volatile solid (VS) ratios of 0:1, 1:2, 1:1, 2:1, and 1:0 (RS/PM), and continuous bench experiments (40L) were carried out at OLRs of 3.0, 3.6, 4.2, 4.8, 6.0, 8.0, and 12.0kg VS/(m(3)d) with optimal VS ratio. The results showed that the optimal ratio was 1:1 in terms of biogas yield. Stable biogas production with an average specific biogas production of 413L/kg VS was obtained at an OLR of 3-8kg VS/(m(3)d). Anaerobic co-digestion was severely inhibited by the accumulation of volatile fatty acids when the OLR was 12kg VS/(m(3)d). Further, light and serious foaming were observed at OLR of 8 and 12kg VS/(m(3)d), respectively.

Keywords: Biogas; Co-digestion; Pig manure; Rice straw; Stability.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Agriculture / methods
  • Animals
  • Bacteria, Anaerobic / metabolism*
  • Bioreactors / microbiology*
  • Computer Simulation
  • Industrial Waste / prevention & control
  • Manure / microbiology*
  • Methane / metabolism*
  • Models, Biological
  • Oryza / microbiology*
  • Plant Stems / microbiology*
  • Refuse Disposal / methods
  • Swine

Substances

  • Industrial Waste
  • Manure
  • Methane