Biochar, a carbon-rich material made from burning plant waste with limited oxygen, can effectively clean polluted soil by trapping harmful chemicals and metals. When mixed into contaminated soil, biochar’s porous structure acts like a sponge to capture pesticides, petroleum products, and toxic metals, preventing them from spreading into groundwater or being absorbed by plants. Scientists have found that combining biochar with plants and beneficial bacteria creates an even more effective cleaning system that can remediate severely contaminated sites.