STUDY OF OPERATING METHOD FOR IMPROVEMENT PERFORMANCE IN A DHS REACTOR WITH PURE OXYGEN SUPPLY TREATING STARCH WASTEWATER

Abstract

 A high dissolved oxygen Down-flow Hanging Sponge (Hi-DHS) reactor was applied as a treatment of starch wastewater. The purpose of this study was to evaluate a difference in performance of Hi-DHS reactor due to wastewater component, and to investigate an operateing method for improvement performance of Hi-DHS reactor. Total COD and total BOD of starch wastewater was 1016 and 565 mg/L respectively. At an HRT of 5 h, organic loading rate was 1.4 kg-BOD/m³ -reactor/d, effluent soluble BOD was over 50 mg/L. This was due to a short cut flow and a shortage of DO supply.Then effluent recircuration was applied to improve these phenomenons. Then effluent soluble BOD was around 25 mg/L. Effluent recircuration suggested that this was a easy method to control biofilm thickness.