Katers, Holzem contribute articles on waste management to dairy publication


Natural and Applied Sciences Profs. John Katers (of EMBI) and Ryan M. Holzem (of the new Environmental Engineering Technology program) recently wrapped up a three-article series for the Progressive Dairyman magazine. Karen Lee, the editor, asked Katers and Holzem to address considerations for using digesters on large dairy farms. The Progressive Dairyman print and online editions reach more than 25,000 large-herd, forward-thinking producers throughout the United States. The articles are summarized below:

* “Considerations for sizing an anaerobic digester,” published online on April 28, 2015, described the need to properly quantify and characterize the manure and water sources that would end up in the digester, and use the appropriate hydraulic and solids retention times to obtain optimal digestion.
* “Four reasons why anaerobic digesters fail,” published online on June 29, examined issues of poor design and equipment selection, lack of technical expertise, maintenance, and inadequate follow-through.
* “Co-digestion considerations for anaerobic digestion systems,” published online Sept. 30, was created as a tear sheet (found at the link). The article discusses the advantages and disadvantages of using off-farm substrates (i.e., distillery waste, dairy waste, food waste, energy crops, and fats oils and greases) in a farms anaerobic digester. The article ends with several important questions that farmers should ask themselves prior to initiating co-digestion with their digester.