Wastewater Treatment Technique of SBR Using Suspended Packing Material and Granular Filter Layer

The field experiment of treatment of combined wastewater was carried out to study the removal efficiency of COD and nitrogen by the pilot setup with suspended packing material and granular filter layer and the drainage technique substituting granular filter layer for decanter. The dissolved oxygen concentration was controlled over 3mg/L. The percentage of removed nitrogen was between 50%similar to 90%. The percentage of removed COD was about 70%. The nitrogen can be efficiently removed under the condition of high dissolved oxygen concentration. The suspended solid concentration of the filter layer effluent is low by means of control of drainage conditions. The backwash is easy and the discharge rate is high.