Abstract: A method is disclosed for solidification of waste fluids such as used antifreeze solutions, thereby facilitating disposal of said waste fluids. The method is applicable to aqueous waste fluids, which may be formed by addition of appropriate amounts of water, if necessary, to the original waste fluids. The method comprises mixing an ion adsorption agent with the aqueous waste fluid, followed by addition of a water-absorbent acrylic polymer material. Following agitation or stirring of the aqueous waste fluid/ion adsorption agent/water-absorbent polymer mixture, solidification is achieved. The solidified mixture is readily handled for disposal such as by incineration.