WASTE WATER TREATING METHOD AND APPARATUS BY RECIRCULATION TYPE TWO-STAGE PACKING LAYER

摘要

PURPOSE:To enhance water purifying action by a microorganism, by repeating such operation that water to be treated is introduced into a first tank provided with a packing layer in a definite flow amount while the partially treated water is transferred to a second tank provided with a packing layer to be further returned to the first tank. CONSTITUTION:Untreated water is charged into a tank A to fill the same so as to reach a position higher than the upper surface of the packing layer 2 therein while a quantitative pump 6 is started and a solenoid valve 7 is operated to transfer untreated water toward a tank B and the water level in the tank A is lowered. As the water level is lowered, untreated water is excluded from the gaps between the packing substances in the packing layer 2 while air begins to be successively sucked from above so as to finally result in that fresh air is uniformly sucked throughout the gaps in the packing layer 2. Therefore, the microorganisms on the surfaces of the packing substances sufficiently absorb oxygen to promote purification. This action is similarly performed in the tank B and untreated water is alternately transferred between the tanks A, B for a predetermined time while treated water after purification is discharged while sterilized by a disinfecting tank 9.