New Technology Could Help Clean Manure
BURLINGTON, Vt. A new technology being promoted by Green Mountain Power and the University of Vermont might clean up manure before it's spread on farm fields, reducing the chances for air and water pollution.
The technology, being sold by a Colchester businessman, uses electricity to kill disease-causing bacteria in liquid manure. That nearly eliminates the odor from the manure by removing 20 percent or more of its phosphorous.
Nonetheless, experts said, the manure retains what's needed for farmers to use it as fertilizer.
"I always start by telling people this is not a silver bullet. It will not eliminate water pollution from farm runoff, but it's one more layer of technology to address the problem," said Buzz Hoerr of Colchester, president of ElectroCell Technologies.
His company is making the portable machines and has sold one to Green Mountain Power for $75,000. Utility executives said it would provide the equipment to its farmer customers. University of Vermont researchers are testing the technology at East Montpelier and South Burlington farms.
"This way, no farmer has to invest a ton of money in machinery," said Mary Powell, Green Mountain senior vice president and chief operating officer. The utility is looking for farmers to volunteer as a test site for the machine.
Phosphorous and nitrogen in manure are nutrients that help to fertilize corn and hay. The bacteria in the manure survives on those nutrients, creating the gas that causes odors.
Crops also can't absorb all of the phosphorous and the excess binds to soil and then is carried into waterways as runoff. The phosphorous causes algae growth in lakes.
Under the ElectroCell technology, liquid manure is run through a large tube carrying an electrical current, which explodes bacteria cell walls, killing it.
"We get a 90 to 95 percent kill ratio. That means the bacteria aren't around to munch on nutrients and give off gas, so a lot of the odor goes away," Hoerr said.
Some phosphorous binds to the dead bacteria, which sinks to sludge at the bottom of a manure pit.
The treated manure is then spread as fertilizer but appears to be absorbed more efficiently by the plants on which it is used. "That's a fundamental research question" that UVM will be studying, said Fran Carr, vice president for research and graduate studies.
It costs about $1,000 in electricity to treat a large manure pit, Powell said. But some farms would have to spend $5,000 to $10,000 improving their service just use the equipment, she said.
Source: Associated Press