METHOD AND DEVICE FOR BATCH OPERATED ACTIVATED SLUDGE TREATMENT

摘要

PURPOSE:To allow simple constitution without affecting the efficiency of removing the BOD in sewage hy making common use of one unit of air blowing machine for two pieces of aerating/settling tanks and repeating intermittent aerations at the time when aeration stages overlap. CONSTITUTION:The sewage is admitted into the one aerating/settling tank 1a in the time of half one cycle and is admitted, after the prescribed time, into another aerating/settling tank 1b. The tanks are thus alternately and evenly operated. The aerating/settling tanks 1 are so operated in the aeration stage that the level of the sewage therein is low for the beginning and increases with an increase in the amt. of the sewage at the time of ending of the stage. Air is force-fed to the aerating/settling tanks 1 by opening and closing an air inflow valve 4 on the side where the water level is lower, i.e., the side where the sewage flows in and holding an air inflow valve 4 on the other side where the water level is side into an open state by utilizing the difference in the height of the water level at the time of the respective aeration stages. the intermittent aerations are executed evenly with both tanks.