Water securityNew technology removes phosphorus from manure
Excess phosphorus, primarily in runoff from land application of manure, accounts for about 66 percent of impaired conditions of U.S. rivers and has created large areas of eutrophication — dead zones — in the Chesapeake Bay and the Gulf of Mexico, where aquatic life cannot survive. Nutrient pollution is one of America’s most widespread, costly and challenging environmental problems. Researchers have developed an innovation that could have a huge impact on water quality problems in the United States, a system capable of removing almost all phosphorus from stored livestock manure.
An innovation that could have a huge impact on water quality problems in the United States, a system capable of removing almost all phosphorus from stored livestock manure, was developed by a team of researchers from Penn State and the U.S. Department of Agriculture’s Agricultural Research Service.
Excess phosphorus, primarily in runoff from land application of manure, accounts for about 66 percent of impaired conditions of U.S. rivers and has created large areas of eutrophication — dead zones — in the Chesapeake Bay and the Gulf of Mexico, where aquatic life cannot survive. Nutrient pollution is one of America’s most widespread, costly and challenging environmental problems, according to the Environmental Protection Agency.
Penn State says that the system devised by Penn State and USDA scientists — dubbed MAPHEX for MAnure PHosphorus EXtraction — involves a three-stage process, including liquid-solid separation with an auger press and centrifuge; chemical treatment with the addition of iron sulfate; and final filtration with diatomaceous earth. The machine is designed to process manure from manure-storage tanks or pits on dairy farms.
“This technology could be a game-changer if we can modify it to achieve lower operating costs,” said lead Penn State researcher Alex Hristov, professor of dairy nutrition in the College of Agricultural Sciences. “The final stage uses diatomaceous earth to filter phosphorous from the fluid and that material is expensive.”
Clinton Church, with USDA Agricultural Research Service’s Pasture Systems and Watershed Management Research Unit, said the team is currently looking at recycling the diatomaceous earth. “We are also trying to find a less expensive substitute for the filtration stage of the MAPHEX process, such as replacing the filtration stage with another centrifuge,” Church said.
