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Farms using technology to separate phosphorus, nitrogen from dairy waste

More dairy farms are using technology originally developed for municipal waste treatment systems.

Josh Gable of Kenosha, Wisconsin-based Centrisys says the process uses a centrifuge to remove solids from liquids. “If we spin the slurry fast enough, the solids will start to partition, so basically, we take the force of gravity and multiply it by the 3-thousand G’s.  Then, things separate really quickly. Then, solids that get extracted out of the water get extracted out of the machine with, essentially, a screw.”

Gable says Centrisys is one of a few companies designing and manufacturing these units.  He says farmers can recapture phosphorus and organic nitrogen while removing it from the wastewater.  “A lot of the phosphorus in dairy manure is actually bound to the solids, so if you can remove the solids, specifically the fine solids, then you can get rid of a large percentage of the phosphorus.”

He says less phosphorus and nitrogen in the manure means less will get into lakes, streams, and groundwater.

Their first dairy manure installation was in 2009.  Now, Centrisis has two dairy farms in Wisconsin using the technology, one in Indiana, and Washington, and six in Colorado, with more inquiries coming in.  There are similar centrifuge-based systems built by other companies being used in agriculture as well.