APPARATUS FOR TREATING WATER TO BE TREATED

PROBLEM TO BE SOLVED: To provide a contact aeration apparatus in which sewage can be made to pass equally among the contact materials packed in a rack. SOLUTION: The lengths C of a pair of side parts 12, 13 of the rack 11, in which the contact material 16 is packed, in the height direction B is made longer than those D of the pair of side parts 12, 13 in the horizontal direction A. The sewage W, which is made to overflow the upper edge of a partition wall 18 by the air diffused from an air diffusion pipe 21, is made to pass among the contact materials 16 at an equal flow rate almost horizontally from the space between the partition wall 18 and the side part 12 of the rack 11. Since the sewage W is made to pass among the contact materials 16 at the equal flow rate all over the height direction B of the rack 11, the treatment efficiency of the sewage W by the contact material 16 can be improved. COPYRIGHT: (C)2008,JPO&INPIT