METHOD AND APPARATUS FOR PURIFYING SEWAGE

PURPOSE:To enhance the treatment efficiency of a solid org. dirty substance in sewage by separating and solubility said dirty substance, by a method wherein a granular porous filter material supporting bacteria is countercurrently contacted with sewage while continuously moved in the same treatment system. CONSTITUTION:Raw water 14 pumped up from a sewage layer by a pump is contacted with a granular porous filter material 13 moving from above to below so as to cross said filter material 13 and filtered to separate the solid org. dirty substance therein while treated water is sent to a treated water tank 9. The slid org. dirty substance caught by the filter material is dissolved by the decomposing action of bacteria supported by the filter material in a solubilizing tank 3. The filter material is washed and regenerated by a filter material washing device 18' and again thrown onto a filter bed 11 through a filter material return pipeline 19 and washing waste water 20 is mixed with raw water 14. The treated water 22 after solubilization is sent to a bioreactor. By this method, filtering work efficiency is enhanced.