INTERMITTENT AERATION METHOD

摘要

PROBLEM TO BE SOLVED: To provide an intermittent aeration method which automatically enables the treatment to be operated under optimum operating conditions to follow up a fluctuation in the load fluctuation of inflow sewage. SOLUTION: This intermittent aeration method comprises treating the sewage by controlling the quantity of the air to be supplied to a reaction vessel in accordance with the result of the measurement of the dissolved oxygen(DO) concn. in the reaction vessel in an aeration stage and maintaining the DO concn. at a prescribed value (DO0 ) according to thereto. The total T0 of one day of the time to hold the DO concn. in the reaction vessel in the aerobic stage at DO0 is previously determined. The quantity of the oxygen to be supplied at which the DO concn. of the reaction vessel attains DO0 from the start of the aerobic stage in the respective intermittent aeration cycles of the next data is controlled in accordance with the differenceΔT of the total of one day between T0 and T1 when the number of times in one day of the intermittent aeration cycles by the equation is defined as M and the time when the DO concn. in the reaction vessel is held at DO0 is defined as T1 in the intermittent cycles of the i-th time (1<=i<=M) of the day.