A material that is capable of releasing an active agent in a controlled manner. The material includes a hydrogel vehicle and an active agent dispersed throughout the hydrogel. When brought into contact with an aqueous release media, the active agent is released from the hydrogel vehicle into the release media. Characteristics of the hydrogel, including composition and surface area, control the release of the agent. Methods of forming the material, dispensing the active agent, and removing the active agent from an aqueous solution are also described.
STATEMENT REGARDING FEDERAL RIGHTS
 This invention was made with government support under Contract No. W-7405-ENG-36, awarded by the U.S. Department of Energy. The government has certain rights in the invention.