story to find out more.
Technician Renee Bigner (top) feeds poultry manure
into the hopper of a pellet mill while chemist Kari Fitzmorris (front) collects
finished pellets. Chemist Isabel Lima monitors the mill's operation by
measuring pellet temperature with an infrared probe. Click the image for
more information about it.
There's Nothing "Foul" About This Poultry
By Erin Peabody
July 7, 2005
It could be considered the scientific
equivalent of turning straw into gold. Chemists with the
Agricultural Research Service have taken
an abundant waste material--chicken manure--and turned it into a prized
filtering product that can clean up polluted waters.
And the only thing needed to induce this impressive transformation: heat.
Marshall, researchers at the ARS
Regional Research Center in New Orleans, La., have found that charring
poultry waste--burning it in an oxygen-free environment--yields a material with
impressive surface area and spongelike qualities, ideal for mopping up
The problem of animal waste disposal and management is a serious one in many
countries. In the United States, food animals produce about 350 billion pounds
of manure a year.
Some of that nutrient-rich waste can be used to fertilize fields. But soils
can easily become too saturated with manure, causing excess nitrogen and
phosphorus from the waste to leach into nearby rivers and waterways--which, in
turn, causes algal blooms and other ecological disruption downstream.
Through their research, Lima and Marshall hoped to find a way to reduce the
mass of burdensome animal waste and possibly discover a profitable, new use for
Exceeding the pair's expectations, the charred poultry litter is a powerful
pollutant magnet. It's especially adept at grabbing heavy metals from
wastewater, such as copper, cadmium and zinc, which are ordinarily tough to
Charred filtering materials are also attractive in that they require less
energy to produce than activated carbons, the current standard material for
filtering pollutants from wastewater.
The ARS scientists think that their unique filtering material can be used in
a variety of waste-treatment scenarios. They've produced pellets, granules and
powders made from the char to accommodate different filtering structures, from
water tanks to columns.
more about this research in the July issue of Agricultural Research
ARS is the U.S. Department of
Agriculture's chief scientific research agency.