Apparatus for sewage treatment

Claim 1

A TANK STRUCTURE FOR TREATING WEST MATERIAL LIQUOR, SAID TANK STRUCTURE COMPRISING A TREATMENT COMPARTMENT FOR INITIAL TREATMENT OF THE LIQUOR, SAID COMPARTMENT BEING ADAPTED TO RECEIVE MEANS FOR AERATING THE LIQUOR IN IT AT A POINT SUBSTANTIALLY BELOW THE SURFACE OF THE LIQUOR, AN INTERMEDIATE SETTLING COMPARTMENT FOR SUBMERGING FLOATABLE MATERIAL AND FOR ALLOWING PRELIMINARY SETTLING OF THE SOLIDS FROM THE LIQUOR, SAID INTERMEDIATE COMPARTMENT HAVING A CROSS SECTION AT ITS UPPPER END WHICH IS SUBSTANTIALLY REDUCED RELATIVE TO ITS CROSS SECTION OVER A MAJOR PORTION OF ITS HEIGHT, A CONDUIT PROVIDING DIRECT COMMUNICATION BETWEEN A POINT ADJACENT THE BOTTOM OF SAID TREATMENT COMPARTMENT AND THE REDUCED UPPER END OF SAID INTERMEDIATE SETTLING COMPARTMENT, SAID CONDUIT SPANNING IN AT LEAST ONE DIRECTION A SUBSTANTIAL PORTION OF SAID REDUCED UPPER END OF SAID INTERMEDIATE COMPARTMENT, A FINAL SETTLING COMPARTMENT FOR ALLOWING FINAL SETTLING OF SOLIDS FROM THE LIQUOR, MEANS PROVIDING DIRECT COMMUNICATION BETWEEN THE LOWER PART OF SAID INTERMEDIATE COMPARTMENT AND THE LOWER PART OF SAID FINAL COMPARTMENT, AND MEANS PROVIDING FOR DISCHARGE FROM THE UPPER PART OF SAID FINAL COMPARTMENT.