New technology treats dairy wastes and odors. (Pollution).
Lagoons traditionally have been used to store manure and liquid effluents from dairy herds. Wastes stored over the winter months are pumped onto fields in the spring, where crops utilize the manure's nutrients. However, more nutrients, such as nitrogen and phosphorous, may be applied to crops than can be used effectively.
"InStreem is designed to use a dairy's existing infrastructure to convert lagoons from waste storage facilities to facilities that solve waste problems," explains John Jaksch, PNNL program manager for the project. "In doing so, this technology addresses one of the dairy industry's most pressing issues."
Unlike conventional treatment methods, InStreem converts existing lagoons into extended aeration systems, establishing conditions favorable for aerobic and anaerobic degradation of wastes. The aerobic process is designed to remove excess nitrogen, and the anaerobic process is designed to remove other nutrient constituents, such as phosphorous. InStreem maintains an oxygen deficit condition in the lagoon and does not overaerate, while still allowing nutrient reduction to take place and bacteria to work on reducing the manure sediments. One InStreem unit treats a lagoon one to one and a half acres in size.
"In three months, the depth of solids dropped from six feet to six inches, and that was during the coldest part of the year," Jaksch points out. "And since InStreem uses a small, five-horsepower engine to circulate the entire lagoon, it's energy efficient." In addition, InStreem has been successful in tackling a problem that is common to all dairies--odor. "Within two weeks of operation, we noticed a huge reduction in odor," says George DeRuyter, owner of the dairy. "Odors on the lagoon banks now are barely detectable."
Equipped with 10 48-inch aeration discs powered by the five-horsepower motor, the floating InStreem unit displaces water in adjustable horizontal and vertical planes around a barrier dividing the lagoon. In dairy applications, the technology replicates fixed-site municipal wastewater biological treatment technologies, used at more than 400 community waste treatment plants across the U.S. and Canada.
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|Publication:||USA Today (Magazine)|
|Article Type:||Brief Article|
|Date:||Jun 1, 2002|
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