Highly swollen acrylamide (AAm)/sodium acrylate (SA) hydrogels were prepared by free radical solution polymerization in aqueous solution of AAm with SA as comonomer and two multifunctional crosslinkers such as glutaraldehyde (GL) and divinylbenzene (DVB). Water absorption and percentage swelling were determined gravimetrically. The influence of SA content in hydrogels was examined. Percentage swelling ratio of AAm/SA hydrogels was increased up to 2946-12,533%, while AAm. hydrogels swelled up to 1326-1618%. The values of equilibrium water content of the hydrogels are between 0.9297-0.9921. Diffusion behavior was investigated. Water diffusion into hydrogels was found to be non-Fickian in character. Adsorption properties of AAm/SA hydrogels in aqueous thionin solution have been investigated. Finally, the amount of sorbed thionin er gram of dry hydrogel (q(e)) was calculated to be 4.81 X 10(-6) - 11.69 X 10(-6) mol thionin per gram for hydrogels. Removal efficiency (RE%) of the AAm/SA hydrogels was changed range 37.03-68.82%. (C) 2007 Wiley Periodicals, Inc.