The study looked at how copper and cadmium behave in different types of soil to help prevent heavy metal pollution. They found that copper is easier to stick to soil than cadmium, especially in farmland soil. Farmland soil has the highest ability to hold onto copper and cadmium compared to grassland and forest soil. The amount of copper and cadmium that can be held by soil increases as the concentration of these metals in the water increases. Overall, farmland soil is the best at keeping copper and cadmium in place, likely due to its high pH, organic matter, and clay content.