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US 4,663,044 AGranted
Biological treatment of wastewater
AssigneeTransfield, Inc.
InventorMervyn C. Goronszy
Life of this patent
Estimating the term…
Abstract
A wastewater treatment reaction vessel is operated with repeated sequences of aeration and non-aeration, using a single vessel or multiple vessels alternately, activated sludge which is acclimated for BOD reduction, nitrification or biological denitrification and phosphorus removal is absorptively reacted with influent wastewater, and the combined flow is passed into subsequent absorptive reactor volumes, reducing the BOD such that the effluent BOD is less than twenty percent that of the influent.
Claims49
A continuous inflow, intermittent flow path, sequential cycle, activated sludge waste water process for treating wastewater, comprising the steps of:
- (a) continuously receiving wastewater into a first zone (A) into which activated sludge from a subsequent zone is mixed and retaining said wastewater in said first zone for a period of from at least approximately two to 20 minutes sufficient to form a non-bulking sludge and absorb biodegradable dissolved compounds into the activated sludge;
- (b) passing wastewater from the first zone (A) into a second zone (B) during at least a first aerating time period into which second zone oxygen is transferred into the wastewater, and passing wastewater into said second zone during a second quiescent time period during which settling of sludge is caused by maintaining a quiescent condition in said second zone;
- (c) passing wastewater from the second zone (B) into a third zone (C) during said first and second time periods, the wastewater passing into the third zone being characterized in that it has less than approximately twenty percent of the biochemical oxygen demand the wastewater originally contained and further characterized in that sludge associated therewith is non-bulking and has a high settling velocity, said third zone (C) being aerated during the first aerating period of time to regenerate the absorption capacity of the sludge and being settled during the second quiescent period of time;
- (d) decanting the upper portion of the wastewater from the third zone (C) during a third decanting period of time during which there is no inflow into the second zone (B) from the first zone (A);
- and
- (e) repeating in cyclic manner steps (b), (c) and (d), the operation of said steps being characterized as a cyclically aerated process, influent wastewater being retained in or before the first zone (A) or directed elsewhere therefrom during the third decanting time period.
3 more elements
A process for treating municipal wastewater to reduce biochemical oxygen demand and remove ammonia,nitrate nitrogen and phosphorus, comprising the steps of:
- (a) in a first zone (A) injecting regenerated activated sludge from a subsequent zone;
- (b) flowing wastewater from the first zone (A) to a second aerated zone (B) into which additional regenerated activated sludge is introduced;
- (c) flowing wastewater from the second zone (B) to a third zone (C) which is aerated to regenerate the activated sludge absorption capacity which is injected into the first zone (A) and introduced into the second zone (B);
- (d) settling the sludge and particulate matter in the second zone (B) and the third zone (C) and thereafter decanting fully wastewater from the upper layers of the third zone (C), there being no inflow from the first zone (A) to the second zone (B) during decantation;
- and
- (e) cyclically repeating steps (b), (c) and (d).
3 more elements
A process for treating wastewater having a high biochemical oxygen demand of from approximately 250 mg/L to approximately 2,000 mg/L and a high soluble biochemical oxygen demand fraction of approximately 50% or more, comprising the steps of:
- (a) in a first zone (A) injecting regenerated activated sludge from a subsequent zone;
- (b) flowing wastewater from the first zone (A) to a second aerated zone (B) into which additional regenerated activated sludge is introduced, said second zone comprising a multiplicity of sub-zones each of which is aerated and into each of which additional regenerated activated sludge is introduced;
- (c) flowing wastewater from the second zone (B) to a third zone (C) which is aerated to regenerate the activated sludge which is injected into the first zone (A) and introduced into the second zone (B);
- (d) settling the sludge and particulate matter in the second zone (B) and the third zone (C) and thereafter decanting fully wastewater from the upper layers of the third zone (C), there being no inflow from the first zone (A) to the second zone (B) during decantation;
- and
- (e) cyclically repeating steps (b), (c) and (d).
3 more elements
A process for treating wastewater comprising the steps of:
- (a) continuously receiving wastewater into a initial absorption zone (A) into which activated sludge from a subsequent zone is mixed and retaining said wastewater in said initial absorption zone for a period of from at least approximately two to 20 minutes sufficient to form a non-bulking sludge and absorb biodegradable dissolved compounds into the activated sludge;
- (b) passing wastewater from the initial absorption zone (A) into at least one of two or more sequenced absorption zones (B.sub.1, B.sub.2) during aeration thereof and passing wastewater into said respective sequenced absorption zones during respective quiescent time periods during which settling of sludge is caused in the respective sequenced absorption zones by maintaining a quiescent condition in said sequenced absorption zones;
- (c) passing wastewater from one sequenced absorption zone (B.sub.1) into one biological degradation zone (C.sub.1) and passing wastewater from another sequenced absorption zone (B.sub.2) into another biological degradation zone (C.sub.2) the wastewater passing into the biological degradation zones being characterized in that it has less than approximately twenty percent of the biochemical oxygen demand the wastewater originally contained and further characterized in that sludge associated there with is non-bulking and has a high settling velocity, said biological degradation zones (C.sub.1, C.sub.2) being aerated to regenerate the absorption capacity of the sludge and being settled during respective quiescent periods;
- and
- (d) decanting the upper portion of the wastewater from one biological degradation zone (C.sub.1) during one period of time and decanting the upper portion of the wastewater from the other biological degradation zone (C.sub.2) during another period of time, there being no inflow from the intial absorption zone (A) into the one sequenced absorption zone (B.sub.1) during the decantation of the one biological degradation zone (C.sub.1), and there being no inflow into the other sequenced absorption zone (B.sub.2) from the initial absorption zone (A) during the decantation of the other biological degradation zone (C.sub.2), the decantation of the respective biological absoption zones (C.sub.1 and C.sub.2) being at different time periods.
2 more elements
Dependencies are inferred from the claim text.