TRC was recently awarded a Yahara WINS grant to develop a pilot scale simple aeration method for removing phosphorous from the discharge of manure digesters. The grant application was developed and submitted by: Bob Stanforth, Alyssa Sellwood, Mike Ursin, Ted O’Connell, Ken Quinn, and John Rice, who are members of multiple TRC CORE teams.
The innovative process outlined in the grant could be an important step to help large dairy farms in reducing phosphorous loading to our lakes and waterways and reducing harmful algal blooms (HABs). HABs are the rapid growth of algae that can cause harm to people, plants, and animals. HABs typically appear as green bubbly mats on the water surface, which can produce toxins that cause a variety of illnesses. HABs are often caused by excessive loading of phosphorous and nitrogen to local water bodies.
While manure treatment is a well-studied area, much of the work has been focused on recycling nutrients and methane generation and recovery. Phosphorus removal from anaerobically digested manure has tended to concentrate on ammonium phosphate precipitation which is not always a simple process. In contrast, simple aeration, if successful, could provide farmers and municipal manure digesters a low cost and effective alternative for recovering phosphorus out of local waterways.
The project is a pilot scale demonstration of using aeration to remove and recover phosphorous from anaerobically digested manure. The process has been demonstrated on a bench scale level, with the next step being a pilot scale demonstration. Bench-scale testing of aeration has shown over 90% phosphorous removal from wastewater.
For more information, contact John M Rice, PE, PH: JRice@trccompanies.com.