Current status of adsorbent for metal ions with radiation grafting and crosslinking techniques

Seko, Noriaki; Tamada, Masao; Yoshii, Fumio

Removal of toxic metals from streaming water and ground water is important task to preserve environment. Radiation processings of grafting and crosslinking can synthesis adsorbent having high performances. Graft adsorbent can be synthesized by using the conventional polymer like polyethylene having variety shapes such as membrane, cloth, and fiber. Especially, the obtained fibrous adsorbent has 100 times higher rate of adsorption than that of commercialized resin. Novel fibrous adsorption for arsenic was synthesized by direct grafting of phosphoric monomer and following zirconium-loading. Fibrous adsorbents of amidoxime and iminodiacetate were applied to the removal of cadmium from the scallop waste. Furthermore, the amidoxime adsorbent is useful to recover rare metal such as uranium and vanadium in seawater. Crosslinked natural polymers like chitin-chitosan in the paste-like state are applicable for the metal adsorbent. This adsorbent can be biodegraded after usage.