Used in water treatment to remove heavy metal ions such as lead, cadmium, and copper from industrial wastewater. The phosphate groups on the silica surface selectively bind to metal ions, making it effective even in acidic conditions. Commonly applied in environmental remediation, mining effluent treatment, and purification of contaminated groundwater. Also utilized in column filtration systems for continuous metal recovery and reuse in industrial processes. Shows high stability and reusability after regeneration with mild acid washing.