TREATMENT METHOD FOR WASTE

PROBLEM TO BE SOLVED : To provide a treatment method for a waste capable of safely and surely making an oxo-anion forming element in a waste harmless, wherein a method using both a metal trapping agent and a reducing agent such as divalent iron salt is proposed to make the waste, containing harmful oxo-anion forming elements such as Cr(VI), Ce, As, Sb, Mo, V, Sn, W, Mn, Hg, P, N, S, B, Cl, Br, I, etc., and/or F, harmless, but there are problems such that a treatment apparatus corrodes and it is impossible to make the waste harmful. SOLUTION : In this treatment method for the waste, (A) at least one selected from a group composed of a rare earth element, a compound thereof, the IV group element and a compound thereof, and (B) the metal trapping agent are added to the waste containing the oxo-anions forming element and /or a halogen element. Therefore, the oxo-anions and /or halogen ions are changed to be harmless.