In what could be a major victory in the wastewater war against nutrient pollution, cutting-edge research is now making it possible to recycle phosphorus from influent and put it to good use for farmers.
“Scientists have taken a pollutant phosphorus from wastewater and infused it into a soil superfood called biochar to really ‘close the loop’ on several widespread agricultural practices,” Good News Network reported. “The biochar itself is made from incinerated organic material inside an oxygen-deprived environment, turning it into a charcoal that acts like an underground rainwater sponge that also delivers the necessary phosphorus and other nutrients for plant growth.”
When phosphorus enters source water, typically as a result of agricultural runoff, it can exacerbate the presence of toxic algae, which poses dangers to wildlife and drinking water. These harmful algal blooms are becoming a growing problem, so the ability to remove phosphorus from wastewater and use it to improve soil health offers a much-needed solution.
“Phosphorus runoff into streams is a major problem for sea life because once this basic element reaches the ocean, it causes giant blooms of algae that block light from reaching the seabed,” added Good News Network. “On its way there, the same problem can occur with riverine plants, and so is also considered pollution in fresh water.”
The method was developed by a team of researchers led by Daniel Strawn, a professor of environmental soil chemistry at the University of Idaho.
“We’re hitting on many factors,” Strawn said, according to Good News Network. “We are recycling phosphorus, producing cleaner water, increasing soil health, and are creating a carbon sink that reduces atmospheric greenhouse gasses, so it really is a multifaceted technology.”
The researchers found that biochar derived from manure was most effective at absorbing phosphorus, followed by active carbon. As manure can typically be disposed of in landfills, this could present an intriguing alternative for agricultural operations to recycle it into biochar instead, then put it to use absorbing phosphorus before it can reach source water.
Wastewater treatment professionals who are vexed by the increasing presence of toxic algae and agricultural operations that are seeking to reduce their nutrient pollution alike may see this research as a major step in solving both problems.
“Biochar has gained significant global market traction as a soil amendment, and Strawn theorizes that wherever there is agriculture, there is phosphorus runoff that could potentially be used to supercharge the material and return the element to the crops of the following season where it belongs,” per Nature World News.