Enhanced adsorption properties of poly(2-acrylamido-2-methyl-1-propansulfonic acid)/silica composite materials for heavy metal ion removal

Poly(2-acrylamido-2-methyl-1-propansulfonic acid)(PAMPS)/silica composite hydrogels have been prepared by in situ free-radical polymerization. The composite hydrogels were used to remove heavy metal ions from aqueous solution under the non-competitive condition. The results showed that the adsorption capacity of the hydrogels increased with the pH values and silica content in the formulation. Furthermore, the synergistic complexation of metal ions was found in the adsorption studies. Regeneration studies suggested that metal rebinding capacity of the hydrogels did not change significantly through repeated applications compared with the first run.