Silver-doped TiO2 (Ag-TiO2) immobilized onto polystyrene (PS) waste was prepared using a thermal attachment method. Its efficiencies as a photocatalyst under UVA light (lambda=365 nm) for the removal of Cr(VI), methylene blue, Escherichia coli, and Aspergillus niger from water were studied. The results showed that Ag-TiO2-PS material removes pollutants at significantly high rates and especially posseses strong disinfection properties. The morphological study of Ag-TiO2-PS material was carried out using X-ray diffraction, scanning electron microscope, and energy dispersive X-ray spectroscopy. The catalyst can be prepared using waste PS employing a simple immobilization method and it is highly effective for the removal of biological and chemical impurities from drinking and underground water supplies.