Overflow water treatment apparatus of confluent water drainage, manufacturing mathod of float media and float media

An overflow water treatment apparatus of a confluent water drainage, a manufacturing method of a floating media used in the same, and the floating media manufactured by the method are provided to offer easy usability and convenience of the apparatus. An overflow water treatment apparatus(200) includes an inlet part(210), a processing tank(205), a lower water treatment part(220), an upper water treatment part(230), a discharge part(240), and a back-wash part(250). A precipitate filter media(222) is filled in the lower water treatment part, and a floating filter media(232) is filled in the upper water treatment part. A distribution part(212) is installed at the inlet part, and is connected with an inlet pipe. A back-wash feeding pipe(216) and a motor-operated valve(216a) are installed at the distribution part. A lower supporting plate(224) is installed on the lower water treatment part. An upper supporting plate(234) is installed at the upper water treatment part. The discharge part includes a first discharge pipe(242) and a second discharge pipe(244). The back-wash part includes a blower(252), a back- wash type pipe(254), a plurality of nozzles(255), and a back-wash discharge pipe(256).