Synthesis of Montmorillonite/Poly(acrylic acid-co-2-acrylamido-2-methyl-1-propane sulfonic acid) Superabsorbent Composite and the Study of its Adsorption

A novel superabsorbent composite was prepared by intercalation polymerization of acrylic acid (AA) and 2- acrylamido-2-methyl-1-propane sulfonic acid (AMPS) in the presence of montmorillonite (MMT), using ammonium persulfate (APS) as an initiator and N,N'-methylenebisacrylamide (MBA) as a cross linker. The superabsorbent composite was characterized by Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), X-ray diffraction (XRD) and thermogravimetric analysis (TGA). Maximum absorbency of the composite in distilled water and 0.9% sodium chloride solution was 722 and 108 g/g, respectively. The composite was used for removal of heavy metal ions from aqueous solutions. Maximum amount of adsorption for Ni²⁺, Cu²⁺ and Pb²⁺ was 211.0, 159.6 and 1646.0 mg/g, respectively, and the adsorption was in accordance with both Langmuir and Freundlich model. The composite could be regenerated and reused in wastewater treatment