GB1387943A - Biological purification of sewage by the activated-sludge process - Google Patents

Abstract

1387943 Biological purification HEINRICH KOPPERS GmbH 18 April 1972 [27 April 1971] 17932/72 Heading C1C An apparatus for purifying sewage by the activated sludge process comprises a tank 1 which is circular in plan and is divided into a central aeration chamber 3 and annular clarifying chamber 4 and pipes 6 (only one shown), for supplying mixed liquor from chamber 3 to chamber 4 in addition to that supplied through gap 15. In chamber 3 is a centrifugal impeller 9 associated with a riser pipe 10 which is in communication with the bottom of chamber 3, with chamber 4 via radial pipes 18 and with sludge trap 20 via pipe 21. The pipes 18 and 21 have adjustable end connections 19 and 23 respectively. The aeration chamber 3 is in communication with trap 20 through pipe 22. In use, mixed liquor in chamber 3 is drawn up riser 10 together with floating materials and liquid from chamber 4 and trap 20 and dispersed back into the chamber 3 by impeller 9, mixed liquor is passed to chamber 4 through pipes 6 and gap 15 and to trap 20 through pipe- 22, activated sludge is returned from chamber 4 to chamber 3 through gap 15 and clarified liquid is discharged at overflow 16.