Ammonia capture may reduce risks to humans, pigs
Posted Dec. 31, 2012
A membrane used to capture ammonia in pig waste could reduce health risks for people and animals.
Concentrated nitrogen captured by the membranes also could be sold as fertilizer.
In 2012, two Department of Agriculture researchers filed for a patent on a system of gas-permeable membranes that “capture and recycle” ammonia from livestock wastewater, according to an article in Agricultural Research Magazine, which is published by the USDA Agricultural Research Service. The membranes may be useful in manure tanks and lagoons at swine production facilities, where they could help swine owners meet air quality requirements, reduce risks to their employees and livestock, and produce a sellable product.
The ARS described the membranes as similar to materials used in waterproof consumer products as well as to biomedical devices that add oxygen to blood and remove carbon dioxide.
In one study, immersing the membrane in liquid manure for nine days reduced the gaseous ammonia in the liquid by 95 percent, from 114.2 milligrams per liter to 5.4, the ARS information states. Repeated use of the process recovered concentrated nitrogen in a clear solution.
The ARS has research projects intended to find ways to reduce releases of odors, pathogens, ammonia, and greenhouse gases from livestock manure; recover nutrients from that manure; develop technologies to convert manure into useful products such as heat and biofuels; reduce nitrous oxide emissions from manure-affected wetlands and stream areas; and find uses for manure treatment byproducts. In March 2011, ARS employees filed a patent application for use of gas-permeable membranes in enclosures such as poultry barns to capture gaseous ammonia.
“The final products are cleaner air inside the barns with benefit for animal health and reduced environmental emissions, and concentrated liquid nitrogen that can be re-used in agriculture,” ARS information states.