Technology that can produce 50 gallons of water from 100 gallons of manure may be ready for commercialization by the end of this year, according to researchers at Michigan State University.
“Here in Michigan we have a tendency to take water for granted,” says Steve Safferman, an associate professor of biosystems and agricultural engineering at MSU, who is involved in the project. “But out west, for example, where drought remains an issue, the accessibility of clean water could make the difference between a farm remaining viable or going out of business,” he says.
According to Safferman, an operation with 1,000 cows will produce about 10 million gallons of manure a year. While roughly 90 percent of the waste is water, “it contains large amounts of nutrients, carbon, and pathogens that can have an environmental impact if not properly managed,” he says.
But with the McLanahan Nutrient Separation System — which uses an anaerobic digester to produce energy from waste, followed by ultrafiltration, air stripping, and reverse osmosis — the manure is turned into water clean enough for livestock to drink, or, at the very least, to dispose of in an environmentally friendly manner.
The process works by extracting nutrients from the manure that can be harmful to the environment and re-uses them as fertilizer, says Jim Wallace, a former MSU student, who now works for McLanahan Corp., which is working to develop the technology.
“For example, we’re able to capture a large percentage of the ammonia that would otherwise be lost in the atmosphere,” Wallace says. “Ammonia is a negative from an air-quality standpoint.”
The researchers ultimately hope to improve the process so that it derives 65 gallons of water per 100 gallons of manure, Wallace says.