Manure contains phosphorus, which can prompt algae blooms if too much gets into water supplies, so places such as dairy farms are anxious to separate out the phosphorus before spreading their farm waste as fertilizer. One way to do that is with a centrifugehttp://hiller-us.com/animal-waste-processing.php
,of all things: Spinning separates the solids from the liquids, taking about half the phosphorus with it.
AP has a story about a farm in Vermont that’s using the process as par tof efforts to keep phosphorus out of Lake Champlain. Here it is.