METHOD FOR REMOVING HARMFUL METAL FROM WASTE VISCUS OF SCALLOP

摘要

PROBLEM TO BE SOLVED: To provide a practical method for efficiently removing harmful metals such as Cd in waste mainly composed of soft body parts such as mid-intestine gland (generally called 'uro' and hereinafter called waste visora) which are discharged without being utilized in food processing of a scallop. SOLUTION: Pulverized matter of waste visora of the scallop (preferably finely pulverized matter) is agitated in an aqueous medium to elute out harmful metals from waste visora pulverized matter in the aqueous medium (harmful metal eluting operation); suspended solid matter in the aqueous medium is precipitated by a coagulant (suspended solid matter coagulating operation); harmful metal-containing aqueous medium after separating the solid matter is brought into contact with a fibrous amidoxime capturing agent manufactured by a radiation graft polymerization method to make the harmful metals to be adsorbed onto the fibrous amidoxime capturing agent (adsorption operation of metal in aqueous phase by using the amidoxime capturing agent); the harmful metals adsorbed by the fibrous amidoxime capturing agent is eluted by a dilute acid to be recovered (adsorbed metal eluting and recovering operation); on the other hand, the separated solid matter is taken outside the system (solid matter discharging operation).