Method of treating sewage and apparatus therefor

Claim 1

A METHOD OF TREATING SEWAGE WHICH COMPRISES ESTABLISHING A TREATMENT ZONE FOR AN AQUEOUS SEWAGE WHEREIN SAID TREATMENT ZONE IS DIVIDED IN THE VERTICAL DIRECTION INTO SPACED UNOBSTRUCTED AREAS SEPARATED BY A CONTACT AREA CONSISTING OF MULTIPLICITY OF UPWARDLY DIRECTED FLOW COURSES OF COEXTENSIVE LENGTH, THE BOUNDARIES OF SAID FLOW COURSES BEING BIOLOGICALLY ACTIVE SURFACES, MIXING SEWAGE WITH AERATED LIQUID IN THE ELEVATIONALLY LOWER OF SAID SPACED UNOBSTRUCTED AREAS TO FORM A MAIN BODY OF LIQUID FOR FLOW FROM SAID ELEVATIONALLY LOWER UNOBSTRUCTED AREA UPWARDLY THROUGH SAID CONTACT AREA, FLOWING SAID BODY OF LIQUID THROUGH SAID FLOW COURSES IN CLOSE PROXIMITY WITH SAID BIOLOGICALLY ACTIVE SURFACES FOR ELIMINATION OF B.O.D., COMMINGLING TREATED LIQUID AFTER PASSING THROUGH SAID FLOW COURSES IN THE SECOND OF SAID UNOBSTRUCTED AREAS, DISCHARGING TO WASTE A VOLUME OF TREATED LIQUID APPROXIMAMTELY EQUAL TO THE VOLUME OF INFLUENT SEWAGE, WITHDRAWING ADDITIONAL TREATED LIQUID FROM THE SECOND OF SAID UNOBSTRUCTED AREAS TO AN AERATION ZONE OUTSIDE SAID TREATMENT ZONE, AERATING THE WITHDRAWN LIQUID TO FORM AN OXYGEN CARRIER WITH A MINIMYM OXYGEN CONTENT OF ABOUT 3 P.P.M., INTRODUCING THE AERATED LIQUID TO THE ELEVATIONALLY LOWER OF SAID SPACED UNOBSTRUUCTED AREAS FOR MIXING TO FORM THE MAIN BODY OF LIQUID AND WASTING SLUDGE FROM SAID CONTAINER.