IMMERSION TYPE MEMBRANE FILTRATION APPARATUS AND METHOD FOR WASHING FILTRATION MEMBRANE

摘要

PROBLEM TO BE SOLVED: To provide an immersion type membrane filtration apparatus in which bubbles for washing the filtration membranes are made large and distribution of the bubbles is made uniform. SOLUTION: This immersion type membrane filtration apparatus comprises a plurality of filtration membranes 6 installed in vertical direction and immersed in water to be treated which is contained in a treatment tank 1 and is enabled to wash the surface of filtration membranes 6 with bubbles 50 by generating the bubbles 50 upward from the lower part of the filtration membranes 6 and sending the bubbles to gaps between the filtration membranes 6 by making the upward stream of the water to be treated to carry the same. The membrane filtration apparatus is provided with an air nozzle 4 installed in the lower part of the treatment tank 1 for generating the bubbles 50 upward, a pressurized air pipeline 3 communicated with the air nozzle 4, and a treated water circulation pipeline 2 communicated with the lower part of the treatment tank 1.