| 摘要 |
PURPOSE:To contrive to improve solid-liquid separation efficiency, by recirculating waste water in the up-and-down direction across the pipe wall of the inner pipe of an aeration tank and supplying air to waste water during recirculation to perform aeration treatment. CONSTITUTION:An aeration tank 2 has an upright inner pipe and an outer pipe 4 mutually communicated at the upper end parts and lower end parts thereof and a rising part U and a downward part D are formed across the pipe wall of the inner pipe to recirculate waste water in the up-and-down direction within the aeration tank 2. Air is injected in waste water during recirculation from a blower 5 through an air feed pipe 6 to perform aeration treatment. Thereafter, waste water is introduced into an ultrafiltration membrane apparatus 20 having an ultrafiltration membrane formed of a collodion membrane or a cured cellophane membrane to separate a solid component. By this method, solid-liquid separation is efficiently performed. |
