methods of using an adsorption medium to remove at least one constituent from a feed stream . the method comprises contacting an adsorption medium with a feed stream comprising at least one constituent and removing the at least one constituent from the feed stream . the adsorption medium comprises a polyacrylonitrile matrix and at least one metal hydroxide homogenously dispersed therein . the adsorption medium may comprise from approximately 15 wt % to approximately 90 wt % of the pan and from approximately 10 wt % to approximately 85 wt % of the at least one metal hydroxide . the at least one metal hydroxide may be selected from the group consisting of ferric hydroxide , zirconium hydroxide , lanthanum hydroxide , cerium hydroxide , titanium hydroxide , copper hydroxide , antimony hydroxide , and molybdenum hydroxide .