PROBLEM TO BE SOLVED: To provide a sewage disposal agent excellent in clarity of a supernatant, requiring short time for agglomeration and deposition, and removing radioactive elements from sewage including radioactive elements, to a degree that the sewage can be discharged as general waste water.SOLUTION: The sewage disposal agent comprises: 100 pts.wt. of a smectite based adsorptive material; 2-200 pts.wt. of polymer coagulant; 0.5-140 pts.wt. of carbonate; and 5-40 pts.wt. of calcium hydroxide.
