in Anaerobic Digestion for Animal Waste Treatment by Understanding Microbial
PI: Lars Angenent
NRI 71.2 Biobased Products and Bioenergy Production Research
overall goal of the proposed study is to improve stability of farm-based
anaerobic digestion treating swine waste. The supporting objectives
to perform hypothesis-driven research to understand the role of syntrophic
bacteria in anaerobic digestion stability; 2.
to develop innovative techniques, which will be used to study the syntrophic
bacteria in anaerobic digestion systems ; and 3.
to validate results with full-scale systems. To improve the stability
of anaerobic digesters a mechanistic understanding of the microbial
population dynamics is required and such information can only be found
when utilizing culture-independent molecular biology techniques
to classify and quantify syntrophic bacteria. Lab-scale anaerobic
sequencing batch reactor (ASBR), serum bottle, and micro-bioreactor
systems will be operated to ascertain if syntrophic bacteria are below
a critical threshold or too sensitive to perturbations for a stable operation of anaerobic digesters
treating swine waste at high-ammonia-N levels. Anaerobic digestion
will remain an important part of any technology designed to obtain bioenergy
from animal waste. Hence, research on stability of farm-based
anaerobic digesters is required to tackle a pretreatment and conversion
step that currently limits the technical and economic efficiency of
bioproduction of fuels from animal wastes (goals of project area 71.2).
Research on anaerobic digesters fits in the agricultural issues of the
USDA to support activities to improve natural resources and environmental
quality, because implementation of anaerobic digesters on the farm assists
in the effective management and protection of the natural resources
with responsible stewardship. In addition, producing methane,
and thus bioenergy, on the farm adds to agricultural opportunity and
rural prosperity, which is another agricultural issue.