Sewage treatment

Claim 1

THE METHOD OF CONTINUOUSLY TREATING WASTES HAVING CONTAMINANT PUTRESCIBLE SOLIDS AND LIQUIDS TO DERIVE THEREFROM A READILY TREATABLE THICKENED SLUDGE OF SUCH SOLIDS AND LIQUIDS, WHICH COMPRISES SUBJECTING SUCH SEWAGE TO CLARIFICATION BY SEDIMENTATION IN A CLARIFIER TO YIELD A SUPERAJACENT BODY OF LIQUOR FOR EFFLUENT FROM THE CLARIFIER AND A SUBJACENT STRATUM OF SLUDGE ADAPTABLE FOR BIOLOGICAL TREATMENT, FEEDING SLUDGE FROM THAT STRATUM TO A SEDIMENTING THICKENER TO YIELD THEREIN A SUPERJACENT BODY OF LIQUOR FOR EFFLUENR FROM THE THICKENER AND A SUBJACENT BED OF THICKENED SLUDGE WHILE CONTROLLING WITHIN LIMITS CERTAIN FACTORS OF (A) DETENTION TIME OF SLUDGE SOLIDS IN THE BED, (B) DEPTH OF THE BED, (C) SOLIDS LOADING RATE INTO THE THICKENER, (D) LIQUID LOADING RATE INTO THE THICKENER, AND (E) SOLIDS-TO-LIQUID RATIO IN THE FEED TO THE THICKENER WHEREBY THE DETENTION TIME IS SHORT ENOUGH TO AVOID SEPTICITY AND GASIFICATION YET LONG ENOUGH TO PRODUCE A SLUDGE OF ABNORMALLY HIGH SOLIDS CONCENTRATION; WHICH FACTORS INVOLVE REGULATING THE DETENTION TIME (A) OF THE SOLIDS IN THE THICKENER BY VARYING THE RATE OF WITHDRAWAL FROM THE BED THEREOF IN THE THICKENER SO THAT THE RATIO OF SLUDGE VOLUME HELD IN THE BED COMPARED WITH THE VOLUME OF THICKENED SLUDGE WITHDRAWN PER DAY FROM THE BED LIES IN A RANGE OF FROM 1/4 TO 3, REGULATING THE DEPTH OF THE BED (B) BY VARYING THE WITHDRAWAL OF THICKENED SLUDGE FROM THE THICKENER TO MAINTAIN THE DEPTH OF THE BED TO LIE IN A RANGE OF FROM 1 TO 5 FEET, REGULATING THE SOLIDS LOADING RATE (C) OF THE DRY WEIGHT OF THE SOLIDS FED TO THE THICKENER BY VARYING THE FEED THEREOF PER DAY TO LIE IN A RANGE OF FROM 4 TO 40 POUNDS PER SQUARE FOOT OF THICKENER AREA, REGULATING THE LIQUID LOADING RATE (D) BY VARYING THE FEED THEREOF PER DAY TO LIE IN A RANGE OF FROM 250 TO 1500 GALLONS PER SQUARE FOOT OF THICKENER AREA, AND REGULATING THE SOLIDS-TO-LIQUID RATIO (E) IN THE FEED TO THE THICKENER BY VARYING THE DILUTION THEREOF TO LIE IN A RANGE OF FROM 1000 TO 6000 PARTS SOLIDS TO EACH MILLION PARTS LIQUIDS; WHICH METHOD PRODUCES A THICKENER SLUDGE WHICH, WHEN INDICATED ON A GRAPH HAVING A SLUDGE SOLIDS CONCENTRATION REPRESENTED ON ITS ORDINATES AND A SLUDGE DETENTION TIME REPRESENTED ON ITS ABSCISSA WILL SHOW A CURVE HAVING A STEEPLY ASCENDING INITIAL INNER PORTION FOLLOWED BY AN INTERMEDIATE BREAK PORTION CONTINUING INTO A SHALLOWLY ASCENDING OUTER PORTION WITH THE SOLIDS CONCENTRATION LYING IN A RANGE SUBSTANTIALLY ABOVE THE STEEPLY ASCENDING PORTION.

Claim 2

THE METHOD OF CONTINUOUSLY TREATING WASTES HAVING CONTAMINANT PUTRESCIBLE SOLIDS AND LIQUIDS TO DERIVE THEREFROM A READILY TREATABLE THICKENED SLUDGE OF SUCH SOLIDS AND LIQUIDS, WHICH COMPRISES SUBJECTING SUCH SEWAGE TO CLARIFICATION BY SEDIMENTATION IN A CLARIFIER TO YIELD A SUPERAJACENT BODY OF LIQUOR FOR EFFLUENT FROM THE CLARIFIER AND A SUBJACENT STRATUM OF SLUDGE ADAPTABLE FOR BIOLOGICAL TREATMENT, FEEDING SLUDGE FROM THAT STRATUM TO A SEDIMENTING THICKENER TO YIELD THEREIN A SUPERJACENT BODY OF LIQUOR FOR EFFLUENR FROM THE THICKENER AND A SUBJACENT BED OF THICKENED SLUDGE WHILE CONTROLLING WITHIN LIMITS CERTAIN FACTORS OF (A) DETENTION TIME OF SLUDGE SOLIDS IN THE BED, (B) DEPTH OF THE BED, (C) SOLIDS LOADING RATE INTO THE THICKENER, (D) LIQUID LOADING RATE INTO THE THICKENER, AND (E) SOLIDS-TO-LIQUID RATIO IN THE FEED TO THE THICKENER WHEREBY THE DETENTION TIME IS SHORT ENOUGH TO AVOID SEPTICITY AND GASIFICATION YET LONG ENOUGH TO PRODUCE A SLUDGE OF ABNORMALLY HIGH SOLIDS CONCENTRATION; WHICH FACTORS INVOLVE REGULATING THE DETENTION TIME (A) OF THE SOLIDS IN THE THICKENER BY VARYING THE RATE OF WITHDRAWAL FROM THE BED THEREOF IN THE THICKENER SO THAT THE RATIO OF SLUDGE VOLUME HELD IN THE BED COMPARED WITH THE VOLUME OF THICKENED SLUDGE WITHDRAWN PER DAY FROM THE BED LIES IN A RANGE OF FROM 1/4 TO 3, REGULATING THE DEPTH OF THE BED (B) BY VARYING THE WITHDRAWAL OF THICKENED SLUDGE FROM THE THICKENER TO MAINTAIN THE DEPTH OF THE BED TO LIE IN A RANGE OF FROM 1 TO 5 FEET, REGULATING THE SOLIDS LOADING RATE (C) OF THE DRY WEIGHT OF THE SOLIDS FED TO THE THICKENER BY VARYING THE FEED THEREOF PER DAY TO LIE IN A RANGE OF FROM 4 TO 40 POUNDS PER SQUARE FOOT OF THICKENER AREA, REGULATING THE LIQUID LOADING RATE (D) BY VARYING THE FEED THEREOF PER DAY TO LIE IN A RANGE OF FROM 250 TO 1500 GALLONS PER SQUARE FOOT OF THICKENER AREA, AND REGULATING THE SOLIDS-TO-LIQUID RATIO (E) IN THE FEED TO THE THICKENER BY VARYING THE DILUTION THEREOF TO LIE IN A RANGE OF FROM 1000 TO 6000 PARTS SOLIDS TO EACH MILLION PARTS LIQUIDS; WHICH METHOD PRODUCES A THICKENER SLUDGE WHICH, WHEN INDICATED ON A GRAPH HAVING A SLUDGE SOLIDS CONCENTRATION REPRESENTED ON ITS ORDINATES AND A SLUDGE DETENTION TIME REPRESENTED ON ITS ABSCISSA WILL SHOW A CURVE HAVING A STEEPLY ASCENDING INITIAL INNER PORTION FOLLOWED BY AN INTERMEDIATE BREAK PORTION CONTINUING INTO A SHALLOWLY ASCENDING OUTER PORTION WITH THE SOLIDS CONCENTRATION LYING IN A RANGE SUBSTANTIALLY ABOVE THE STEEPLY ASCENDING PORTION.