Greg Moller and and Dan Strawn might have produced the world's first carbon negative advanced water treatment process, because it uses biochar - charcoal made from wood - that can be later used by farmers as fertilizer.
Moller, a University of Idaho College of Agriculture and Life Sciences faculty member with a joint faculty appointment at Washington State University, and Strawn, a UI professor of soil chemistry, call the project N-E-W Tech, or Nutrient-Energy-Water Technology.
They are using biochar to sterilize the wastewater going through the Troy Wastewater Treatment Plant so it can be reused. One of those uses could be drinking water.
Moller said the water he and fellow researchers treated earlier at the Moscow Wastewater Treatment Plant met or exceeded drinking water quality.
The ultimate goal, Moller said, "is to take extraordinarily polluted waters and reclaim that water for unrestricted reuse and one of those unrestricted uses is for drinking water."
Other uses are for agricultural purposes, injecting the sterilized water back into groundwater and aquifers, as well as for things like car washes, Moller said.
"It's a water harvesting technology and process," Moller said. "We're trying to address those potential chemical and microbiological contaminants that would restrict its use."
The charcoal also binds nitrogen and phosphorus to itself from the wastewater. Those two nutrients can be used for agricultural fertilizer, and the carbon in the charcoal ends up in the ground rather than in the atmosphere.
Moller, Strawn and graduate and undergraduate students have been researching and testing at a laboratory trailer at the Troy plant since late spring, Moller said.
Martin Baker, lead field engineer, was performing the water treatment process Wednesday at the Troy plant.
Baker adds biochar, iron and ozone to the water from the plant, which would otherwise dump into Bear Creek, Moller said.
Moller said the biochar, ozone and iron help destroy chemicals, like pharmaceuticals, antibiotics, hormones and pathogens that can remain in treated wastewater.
Sterilization is the ultimate level of the pathogen-free water target of the process, he said.
The biochar binds the nitrogen and phosphorus that remain in the wastewater to itself, he said. When no longer usable as a water filter, the biochar can be used as fertilizer, releasing nitrogen and phosphorus into the soil to help plant growth and itself creating better soil that retains moisture more efficiently, Moller said.
Moller said he and Strawn want to stabilize the nitrogen so it feeds plants but does not run off into surface water and groundwater. Moller said high nitrate water levels could cause health problems, and it is difficult to extract nitrogen from groundwater.
Moller said ozone acts as an oxidizing agent on chemicals in wastewater similar to how bleach works on clothes.
"Iron helps the ozone destroy chemicals and microorganisms and also binds the phosphorus and biochar in the wastewater as recovery for fertilizer," Moller said.
Moller said some trace chemicals found in wastewater need to be destroyed before reaching waterways because they are extremely bioactive. He said pathogens like antibiotic-resistant bacteria, which are a public health threat, need to be destroyed, as well, in advanced water treatment.
He noted that current clean water regulations don't require pharmaceuticals to be removed from wastewater in the U.S.
Moller said the goal is to have this water treatment process be practical to use in both large cities and small communities.
The state of Idaho funded the project for about $500,000 and one of the patents pending is titled, "Biochar Water Treatment," Moller said.
Garrett Cabeza can be reached at (208) 883-4631, or by email to email@example.com.