Sewage treatment process

Claim 1

THE PROCESS OF PURIFYING AN ORGANIC-POLLUTED LIQUID WHICH COMPRISES MIXING UNTREATED POLLUTED LIQUID WITH SEEDING MATERIAL IN THE FORM OF SLUDGE SEGREGATED FOR RECIRCULATION AND WHICH HAS BEEN HELD UNDER ANAEROBIC CONDITIONS TO FORM A BODY OF AQUEOUS MIXTURE FOR DIRECT INTRODUCTION INTO A ZONE OR AERATION, INTRODUCING AIR INTO SAID BODY OF AQUEOUS MIXTURE FOR A PERIOD OF IN QUANTITIES TO SATISFY A MAJOR PORTION OF THE B.O.D. INTRODUCED INTO SAID BODY OF AQUEOUS MIXTURE, FLOWING TREATED MIXTURE FROM THE BODY OF AQUEOUS MIXTURE TO A SETTLING ZONE, DISCHARGING A CLARIFIED LIQUID FROM SAID SETTLING ZONE, WITHDRAWING A CONCENTRATE OF SETTLED SOLIDS FROM SAID SETTLING ZONE TO A HOLDING ZONE WHERE SAID CONCENTRATE IS MAINTAINED IN AN AGITATED CONDITION AND UNDER ANAEROBIC CONDITIONS, THE TOTAL TIME FOR SAID SOLIDS IN THE SETTLING ZONE PLUS THE TIME IN SAID HOLDING ZONE FOR A PERIOD OF FROM ONE TO SEVEN HOURS, WITHDRAWING A PORTION OF THE ANAEROBICALY TREATED CONCENTRATE FROM SAID HOLDING ZONE AND RECYCLING IT TO THE BODY OF MIXED LIQUOR AS THE SEEDING MATERIAL AND CONTINUING AIR INTRODUCTION AS LONG AS THERE IS INTRODUCTION OF POLLUTED LIQUOR WHEREBY A REDUCTION IN SOLIDS REMAINING IN THE SYSTEM TO BE WSTED IS ATTAINED.