Is Biochar a remedy for the toxic soils of the past?
If you’re over 45, you may have heard of DDT, a pesticide used to kill malaria carrying mosquitos and other pests, its legacy is decades of toxic soil. It was eventually banned from US agriculture in 1972 and worldwide in 2004.
But DDT pollution remains a significant problem globally, persisting in soils decades after its ban.
But could the answer lie in a new natural product – biochar? Researchers at Chalmers University of Technology, Sweden, have developed an innovative method using biochar to manage ecological risks from DDT-contaminated soil.
It could pave the way for reclaiming land deemed unusable, contributing to emission reductions and environmental restoration.
Biochar, similar to charcoal, is produced from organic waste through pyrolysis, a process that operates without oxygen. This eco-friendly material binds contaminants and enhances soil health.
In a three-year study, the researchers found that mixing biochar into contaminated soil halved DDT uptake by earthworms.
“Biochar binds DDT efficiently, so that it is not taken up by soil organisms,” said Paul Drenning, postdoctoral researcher at Chalmers.
“Treatment with biochar on site could thus make the land useful instead of being left uncultivated or degraded,” he added.
The reduced bioavailability of DDT in the soil decreases its spread through the food chain, lowering the risk to wildlife and humans.
As biochar decomposes slowly, the effects of this treatment could last for decades. Chalmers’ researchers are exploring ways to scale up the use of biochar, aiming to transform polluted sites into productive, emission-reducing landscapes.
