Acid mine drainage from mining operations contains toxic cadmium that pollutes water supplies. This research shows that naturally occurring bacteria (Acidithiobacillus ferrooxidans) can help remove cadmium by forming iron minerals. Adding calcium and potassium ions together significantly improves this process, with cadmium being trapped in mineral precipitates rather than just adsorbed to surfaces. This biological approach offers a practical and sustainable method for treating contaminated mining water.