METHOD FOR FILTERING TREATMENT OF ORIGINAL WATER AND ITS APPARATUS

PURPOSE:To make clogging of a filter material hardly occur and to apply directly filtering treatment without performing pretreatment even when the concn. of suspending substances in an original water is high by making the amt. of the floating substances caught by the filter material decrease remarkably. CONSTITUTION:A filtering container 2 wherein sands 3 and 4 are placed in the lower part and a space 6 is formed in the upper part is used and an original water W1 contg. suspending substance SS and a power water W4 wherein a large amt. of air is dissolved under pressure are fed in the space so as to mix both waters and majority of the suspending substance SS in the original water W1 is caught with a number of air bubbles A coming out from the power water W1. Then, the suspending substance SS with the air bubbles A is floated and separated on the uppermost part of the filtering container 2 and the original water wherein the amt. of susbending substance SS is decreased by floating and suspending is passed though the sands 3 and 4 to make the remaining suspending substance SS is the original water W1 caught by the sands 3 and 4 and the original water W1 is turned thereby into a clean treated water W2.