METHOD AND DEVICE FOR CONTROLLING WATER SPRAYING RATE OF VARIABLE VOLUME BIOREACTOR

PURPOSE:To prevent the degradation in a treatment function by automatically adjusting a water spraying rate in conformity with the fluctuation in a water level. CONSTITUTION:Org. waste water 5 introduced into a biotreatment reaction vessel 1 flows upward and downward in a biomembrane fixed filter bed 2 according to a change in the inflow and outflow rates. The biomembrane fixed filter bed 2 is completely immersed in said water at the time of the high level. The filter bed 2 is completely exposed at the time of the low level. An air diffusion pipe 3 is disposed below the filter bed 2 and air is supplied from an aeration blower 4; therefore, the biooxidation treatment by an immersion filter bed method is executed in the part of the filter bed 2 under the water surface of the org. waste water 5 the water level of which fluctuates upward and downward. A controller 11 calculates the deficiency of oxygen upon rising of the water level and activates the aeration via an inverter 12. The biomembranes propagated in the filter bed 2 by such aeration are stripped by the water spraying effect at the time of the low level by which the energy is saved.