The psyllium husk, a natural polysaccharide, was modified to develop novel green polymeric materials for use in wastewater treatment technologies. Graft copolymers and three-dimensional interpenetrating networks (IPNs) of psyllium (Psy) and methacrylic acid (MAAc) were prepared using ammonium persulphate (APS) as initiator. Network formation was carried out using N,N-methylenebisacrylamide (N,N-MBAAm) as crosslinker. The hydrogels, thus formed, were characterized using scanning electron microscopy (SEM), FTIR spectroscopy, and thermogravimetric analysis (TGA) to derive the structure-property correlation. Swellability of these hydrogels was analyzed in distilled water and aqueous NaCl solution as a function of time, temperature, pH, and [NaCl]. Flocculation efficiency of graft polymers was analyzed against aqueous kaolin suspension of known concentration as a function of settling time, temperature, amount of polymer, and pH. Novel polymeric materials were also used for the treatment of total hardness in tap water. (c) 2006 Wiley Periodicals, Inc.