完全混合式 반응조와 充塡塔 반응조를 수직으로 연결한 새로운 형태의 폐수처리 장치를 고안하였다. 4.16ℓ의 完全混合 반응조는 內部에 원통형의 流路를 설치함으로써 自動的으로 혼합이 되도록 하였고, 둘째단으로 가기 전에 슬러지가 재순환되도록 하였다. 充塡塔의 부피는 1.84ℓ였으며 Raschig ring으로 充塡하였다. 4,7,10,15 時間의 네가지 체류시간과 292, 674, 1300㎎/ℓ COD의 세가지 유기물 농도에 대하여 각각 실험하였다. 유기물 負荷 1.6-1.9㎏ COD/㎥·day에서 90%이상의 處理效率을 보여주었는데 充塡塔의 마무리효과는 一段 瀑氣槽의 배출류를 기준으로 約 70%를 나타내었다. 슬러지 發生率은 gCOD 當 0.21∼0.31g으로 다른 공정에 비하여 낮았으며, 廢슬러지의 SVI는 최적 負荷에서 26.2-36.6이었다.

A new dual biological reactor system for wastewater treatment was developed by combining CSTR and PBR. A circular tank of 4.16 liters with a concentric draft tube was used for the first stage and a column of 1.84 liters packed with Raschig rings was vertically attached. By arranging two reactors in one column, it is unnecessary to install a separate sludge settler for recycle. The process was operated with various combinations of four retention times (4, 7, 10, 15 hours) and three organic concentrations (292, 675, 1300 ㎎/liter COD) with synthetic sewage. It was found that the process was capable of removing more than 90% of COD under organic loadings of 1.6 to 1.9 ㎏ COD/㎥·day. Results for polishing in PBR showed that about 70% of the influent COD from CSTR was removed and the effluent SS was maintained less than 30 ㎎/liter. The sludge yield was 0.21 to 0.31 g SS/g COD removed, and the SVI for an optimumorganic loading was in the range 26.2 to 36.6.