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Stability in AD Treating Animal Waste


Improving Stability in Anaerobic Digestion for Animal Waste Treatment by Understanding Microbial Ecology

PI: Lars Angenent

NRI 71.2 Biobased Products and Bioenergy Production Research


The overall goal of the proposed study is to improve stability of farm-based anaerobic digestion treating swine waste.  The supporting objectives are: 1.  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.



Dr. Amy Shen

Dr. Christine Floss



Marcelo Garcia