Patent US3355809A successfully refreshed from Google Patents.
Patent US2168230A successfully refreshed from Google Patents.
US4292176A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Use of activated carbon in waste water treating process
Assignee: BP Corp North America Inc
•
Filing: 1980-08-14
•
Granted: 1981-09-29
•
Expires: 2000-08-14
Abstract
Abstract Disclosed is a process for treating waste water through the use of activated carbon. The carbon is generally added to waste water having a pH from about 4 to about 11, and is commonly added after the waste water has undergone primary treatment. Preferred modes of operation comprise using low concentrations of activated carbon having a high surface area and a zeta potential greater than about -10 millivolts. It is also preferred to use activated carbon in conjunction with an activated sludge process having an average sludge age greater than about ten days, especially where the waste water undergoes a pretreatment prior to the activated sludge process to reduce chemical oxygen demand, oil and solids content. Low concentrations of activated carbon based on feed waste water are generally used while maintaining substantially higher carbon concentrations in the process.
Inventors
- 👤 James F. Grutsch
- 👤 Russell C. Mallatt
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 00:48
CPC Classifications
C; C02; C02F; C02F3/00; C02F3/02; C02F3/12; C02F3/1205; C02F3/1226; B; B01; B01J; B01J20/00; B01J20/02; B01J20/20; C01; C01B; C01B32/00; C01B32/30; C01B32/312; C01B32/336; C01B32/354; C01B32/378; C02F1/00; C02F1/28; C02F1/283; C02F3/26; C02F9/00; Y; Y02; Y02W; Y02W10/00; Y02W10/10
Claims Analysis
Total Claims: 71
Claim 1
Independent Claim
162 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a first portion of said separated sludge being recycled for recontact with the water in the first stage and a second portion of said separated sludge being treated in downstream operations, the improvement comprising pretreating the contaminated water entering the first stage so that the water contains less than about 20 ppm of hydrocarbons and less than about 20 ppm of solids; introducing 1 to 40 ppm based on feed waste water of activated carbon having a zeta potential of at least about -10 millivolts into the water so that the carbon is present in the first and/or second stage; and maintaining the average age of the activated sludge in the first and second stages in excess of ten days.
Claim 2
Dependent Claim
162 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a first portion of said separated sludge being recycled for recontact with the water in the first stage and a second portion of said separated sludge being treated in downstream operations, the improvement comprising pretreating the contaminated water entering the first stage so that the water contains less than about 20 ppm of hydrocarbons and less than about 20 ppm of solids; introducing 1 to 40 ppm based on feed waste water of activated carbon having a zeta potential of at least about -10 millivolts into the water so that the carbon is present in the first and/or second stage; and maintaining the average age of the activated sludge in the first and second stages in excess of ten days.
Claim 3
Dependent Claim
21 words
The process of claim 1 wherein the carbon has a surface area of at least about 1500 square meters per gram.
Claim 4
Dependent Claim
21 words
The process of claim 1 wherein the carbon has a surface area of at least about 2000 square meters per gram.
Claim 5
Dependent Claim
44 words
The process of claim 1 wherein oxygen is introduced into the water and sludge mix entering the second stage so that the sludge in the second zone is maintained in a aerobic state and separated decontaminated water from said second stage contains dissolved oxygen.
Claim 6
Dependent Claim
26 words
The process of claim 4 wherein the water from the second stage contains at least about one part of dissolved oxygen per million parts of water.
Claim 7
Dependent Claim
40 words
The improved process of claim 1 wherein the oxygen is introduced into the water and sludge mix entering the second stage by introducing air into a stream of the water and sludge mix flowing between the first and second stages.
Claim 8
Dependent Claim
42 words
The improved process of claim 6 wherein the oxygen in the stream of water and sludge mix flowing between the first and second stage is subjected to a high pressure produced by hydrostatic heads of liquid in the first and second stages.
Claim 9
Dependent Claim
35 words
The improved process of claim 1 where a part of the first portion of the separated recycle sludge is mixed with the stream of water and sludge mix flowing between the first and second stages.
Claim 10
Dependent Claim
41 words
The improved process of claim 1 where said second portion of the sludge treated in downstream operations is forwarded through a third stage for thickening, and the thickened sludge from the third stage is forwarded to a fourth stage for digestion.
Claim 11
Dependent Claim
29 words
The improved process of claim 9 where a portion of the thickened sludge from the third stage is mixed with the water and sludge mix entering the second stage.
Claim 12
Dependent Claim
29 words
The improved process of claim 9 where a portion of the digested sludge from the fourth stage is mixed with the water and sludge mix entering the second stage.
Claim 13
Dependent Claim
27 words
The improved process of claim 1 where oxygen is introduced into the contaminated water entering the first stage by aspirating air into a stream of said water.
Claim 14
Dependent Claim
30 words
The improved process of claim 12 wherein the oxygen in the stream of water entering the first stage is subjected to high pressure produced by a hydrostatic head of liquor.
Claim 15
Dependent Claim
27 words
The improved process of claim 9 where oxygen is introduced into the sludge flowing between the second and third stages, and between the third and fourth stages.
Claim 16
Dependent Claim
15 words
The process of claim 1 wherein the activated carbon is introduced after the first stage.
Claim 17
Dependent Claim
18 words
The process of claim 1 wherein the activated carbon is introduced to the water leaving the first stage.
Claim 18
Dependent Claim
15 words
The process of claim 1 wherein the activated carbon is introduced after the second stage.
Claim 19
Dependent Claim
19 words
The process of claim 1 wherein the activated carbon is introduced to the decontaminated water leaving the second stage.
Claim 20
Dependent Claim
24 words
The process of claim 18 wherein water leaving the second stage is subjected to filtration by filters subsequent to the introduction of activated carbon.
Claim 21
Dependent Claim
23 words
The process of claim 19 wherein the filters are occasionally backwashed to reduce filter plugging and remove activated carbon and residual organic material.
Claim 22
Dependent Claim
19 words
The process of claim 20 wherein the activated carbon and residual organic material are backwashed to the first stage.
Claim 23
Dependent Claim
54 words
The process of claim 19 wherein said second portion of the sludge treated in downstream operations is forwarded through a third stage for thickening, and the thickened sludge from the third stage is forwarded to fourth stage for digestion, and wherein the activated carbon and residual organic material are backwashed to the fourth stage.
Claim 24
Dependent Claim
34 words
The process of claim 11 wherein the activated carbon is introduced into the portion of the digested sludge from the fourth stage which is mixed with the water and sludge entering the second stage.
Claim 25
Dependent Claim
204 words
The process of claim 1 wherein the contaminated water undergoes intermediate treatment prior to the activated sludge process comprising passing the water through an equalization zone including at least two separate water retention compartments in series so that the water is mixed in each compartment and flows from one compartment to the next compartment and a given quantity of water is retained for predetermined period in each of said compartments, introducing air into the water in at least one of the compartments so that the water in the compartment is vigorously agitated and the effluent in the aerated compartment includes at least one part of dissolved oxygen per million parts of water, adjusting the pH of the water in the equalization zone so that the pH of the water in one of the compartments and in the effluent from said zone ranges between about 6.5 and about 9.5, destabilizing colloidal particles suspended in the water, and treating by filtration or dissolved air flotation the effluent water from the equalization zone so that said filtered water includes no more than about twenty parts of hydrocarbons per million parts of water and no more than about twenty parts of suspended solids per million parts of water.
Claim 26
Dependent Claim
20 words
The process of claim 1 wherein the carbon has a surface area greater than about 2500 square meters per gram.
Claim 27
Dependent Claim
16 words
The process of claim 1 wherein the average sludge age is greater than about 20 days.
Claim 28
Dependent Claim
21 words
The process of claim 1 wherein the first stage is operated at an average sludge age in excess of thirty days.
Claim 29
Dependent Claim
22 words
The process of claim 1 wherein the carbon has a zeta potential in the range of about -5 to about +5 millivolts.
Claim 30
Dependent Claim
98 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a portion of said separated sludge being recycled for recontact with water in the first stage, the improvement comprising introducing about 1 to about 500 ppm of activated carbon into the water so that the carbon is present in the first or second stages, said carbon having a zeta potential of at least about -10 millivolts.
Claim 31
Dependent Claim
98 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a portion of said separated sludge being recycled for recontact with water in the first stage, the improvement comprising introducing about 1 to about 500 ppm of activated carbon into the water so that the carbon is present in the first or second stages, said carbon having a zeta potential of at least about -10 millivolts.
Claim 32
Dependent Claim
19 words
The process of claim 29 wherein said carbon has a zeta potential of about -5 to about +5 millivolts.
Claim 33
Dependent Claim
39 words
In a waste water treating process wherein waste water having a pH of from about 4 to about 11 is contacted with activated carbon, the improvement comprising maintaining the zeta potential of the carbon at least about -10 millivolts.
Claim 34
Dependent Claim
39 words
In a waste water treating process wherein waste water having a pH of from about 4 to about 11 is contacted with activated carbon, the improvement comprising maintaining the zeta potential of the carbon at least about -10 millivolts.
Claim 35
Dependent Claim
20 words
The process of claim 31 wherein polyelectrolytes are added to the waste water in order to control the zeta potential.
Claim 36
Dependent Claim
128 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a portion of said separated sludge being recycled for recontact with water in the first stage, the improvement comprising pretreating the waste water prior to the first stage to reduce the chemical oxygen demand of the waste water by fifty percent; operating the first or second stages in the presence of activated carbon having a zeta potential of at least about -10 millivolts by the addition of 1-40 ppm activated carbon based on feed water; and maintaining the average sludge age in excess of 10 days.
Claim 37
Dependent Claim
128 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a portion of said separated sludge being recycled for recontact with water in the first stage, the improvement comprising pretreating the waste water prior to the first stage to reduce the chemical oxygen demand of the waste water by fifty percent; operating the first or second stages in the presence of activated carbon having a zeta potential of at least about -10 millivolts by the addition of 1-40 ppm activated carbon based on feed water; and maintaining the average sludge age in excess of 10 days.
Claim 38
Dependent Claim
20 words
The process of claim 33 wherein the contaminated feed water is pretreated to reduce chemical oxygen demand by seventy percent.
Claim 39
Dependent Claim
24 words
The process of claim 33 wherein the water is pretreated to reduce chemical oxygen demand to consist of essentially only the soluble organic component.
Claim 40
Dependent Claim
154 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a first portion of said separated sludge being recycled for recontact with the water in the first stage and a second portion of said separated sludge being treated in downstream operations, the improvement comprising pretreating the contaminated water entering the first stage so that the water contains less than about 20 ppm of dispersed hydrocarbons and less than about 20 ppm of solids; introducing 1 to 40 ppm based on feed waste water of activated carbon into the waste water so that the carbon is present in the first and/or second stage; and maintaining the average age of the activated sludge in the first and second stages in excess of ten days.
Claim 41
Dependent Claim
154 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a first portion of said separated sludge being recycled for recontact with the water in the first stage and a second portion of said separated sludge being treated in downstream operations, the improvement comprising pretreating the contaminated water entering the first stage so that the water contains less than about 20 ppm of dispersed hydrocarbons and less than about 20 ppm of solids; introducing 1 to 40 ppm based on feed waste water of activated carbon into the waste water so that the carbon is present in the first and/or second stage; and maintaining the average age of the activated sludge in the first and second stages in excess of ten days.
Claim 42
Dependent Claim
21 words
The process of claim 36 wherein the carbon has a surface area of at least about 1500 square meters per gram.
Claim 43
Dependent Claim
21 words
The process of claim 36 wherein the carbon has a surface area of at least about 2000 square meters per gram.
Claim 44
Dependent Claim
44 words
The process of claim 36 wherein oxygen is introduced into the water and sludge mix entering the second stage so that the sludge in the second zone is maintained in an aerobic state and separated decontaminated water from said second stage contains dissolved oxygen.
Claim 45
Dependent Claim
26 words
The process of claim 39 wherein the water from the second stage contains at least about one part of dissolved oxygen per million parts of water.
Claim 46
Dependent Claim
40 words
The improved process of claim 36 wherein the oxygen is introduced into the water and sludge mix entering the second stage by introducing air into a stream of the water and sludge mix flowing between the first and second stages.
Claim 47
Dependent Claim
42 words
The improved process of claim 41 wherein the oxygen in the stream of water and sludge mix flowing between the first and second stages is subjected to a high pressure produced by hydrostatic heads of liquid in the first and second stages.
Claim 48
Dependent Claim
35 words
The improved process of claim 36 where a part of the first portion of the separated recycle sludge is mixed with the stream of water and sludge mix flowing between the first and second stages.
Claim 49
Dependent Claim
41 words
The improved process of claim 36 where said second portion of the sludge treated in downstream operations is forwarded through a third stage for thickening, and the thickened sludge from the third stage is forwarded to a fourth stage for digestion.
Claim 50
Dependent Claim
29 words
The improved process of claim 44 where a portion of the thickened sludge from the third stage is mixed with the water and sludge mix entering the second stage.
Claim 51
Dependent Claim
29 words
The improved process of claim 44 where a portion of the digested sludge from the fourth stage is mixed with the water and sludge mix entering the second stage.
Claim 52
Dependent Claim
27 words
The improved process of claim 36 where oxygen is introduced into the contaminated water entering the first stage by aspirating air into a stream of said water.
Claim 53
Dependent Claim
30 words
The improved process of claim 47 wherein the oxygen is the stream of water entering the first stage is subjected to high pressure produced by a hydrostatic head of liquor.
Claim 54
Dependent Claim
27 words
The improved process of claim 44 where oxygen is introduced into the sludge flowing between the second and third stages, and between the third and fourth stages.
Claim 55
Dependent Claim
15 words
The process of claim 36 wherein the activated carbon is introduced after the first stage.
Claim 56
Dependent Claim
18 words
The process of claim 36 wherein the activated carbon is introduced to the water leaving the first stage.
Claim 57
Dependent Claim
15 words
The process of claim 36 wherein the activated carbon is introduced after the second stage.
Claim 58
Dependent Claim
19 words
The process of claim 36 wherein the activated carbon is introduced to the decontaminated water leaving the second stage.
Claim 59
Dependent Claim
24 words
The process of claim 53 wherein water leaving the second stage is subjected to filtration by filters subsequent to the introduction of activated carbon.
Claim 60
Dependent Claim
23 words
The process of claim 54 wherein the filters are occasionally backwashed to reduce filter plugging and remove activated carbon and residual organic material.
Claim 61
Dependent Claim
19 words
The process of claim 55 wherein the activated carbon and residual organic material are backwashed to the first stage.
Claim 62
Dependent Claim
55 words
The process of claim 54 wherein said second portion of the sludge treated in downstream operations is forwarded through a third stage for thickening, and the thickened sludge from the third stage is forwarded to the fourth stage for digestion, and wherein the activated carbon and residual organic material are backwashed to the fourth stage.
Claim 63
Dependent Claim
34 words
The process of claim 46 wherein the activated carbon is introduced into the portion of the digested sludge from the fourth stage which is mixed with the water and sludge entering the second stage.
Claim 64
Dependent Claim
204 words
The process of claim 36 wherein the contaminated water undergoes intermediate treatment prior to the activated sludge process comprising passing the water through an equalization zone including at least two separate water retention compartments in series so that the water is mixed in each compartment and flows from one compartment to the next compartment and a given quantity of water is retained for predetermined period in each of said compartments, introducing air into the water in at least one of the compartments so that the water in the compartment is vigorously agitated and the effluent in the aerated compartment includes at least one part of dissolved oxygen per million parts of water, adjusting the pH of the water in the equalization zone so that the pH of the water in one of the compartments and in the effluent from said zone ranges between about 6.5 and about 9.5, destabilizing colloidal particles suspended in the water, and treating by filtration or dissolved air flotation the effluent water from the equalization zone so that said filtered water includes no more than about twenty parts of hydrocarbons per million parts of water and no more than about twenty parts of suspended solids per million parts of water.
Claim 65
Dependent Claim
20 words
The process of claim 36 wherein the carbon has a surface area greater than about 2500 square meters per gram.
Claim 66
Dependent Claim
16 words
The process of claim 36 wherein the average sludge age is greater than about 20 days.
Claim 67
Dependent Claim
21 words
The process of claim 36 wherein the first stage is operated at an average sludge age in excess of thirty days.
Claim 68
Dependent Claim
119 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a portion of said separated sludge being recycled for recontact with water in the first stage, the improvement comprising pretreating the waste water prior to the first stage to reduce the chemical oxygen demand of the waste water by fifty percent; operating the first or second stages in the presence of activated carbon by the addition of 1-40 ppm activated carbon based on feed waste water; and maintaining the average sludge age in excess of 10 days.
Claim 69
Dependent Claim
119 words
In the activated sludge process wherein a first stage contaminated water is contacted with activated sludge for a period of time sufficient to biologically degrade contaminants in the water and in a second stage decontaminated water is separated from the activated sludge, a portion of said separated sludge being recycled for recontact with water in the first stage, the improvement comprising pretreating the waste water prior to the first stage to reduce the chemical oxygen demand of the waste water by fifty percent; operating the first or second stages in the presence of activated carbon by the addition of 1-40 ppm activated carbon based on feed waste water; and maintaining the average sludge age in excess of 10 days.
Claim 70
Dependent Claim
19 words
The process of claim 63 wherein the waste water is pretreated to reduce chemical oxygen demand by seventy percent.
Claim 71
Dependent Claim
25 words
The process of claim 63 wherein the waste water is pretreated to reduce chemical oxygen demand to consist of essentially only the soluble organic component.
References Cited (Backward Citations)
US3803029A
Cited
US3904518A
Cited
US4073722A
Cited
US4076615A
Cited
US4207179A
Cited
US4168228A
Cited
US4172781A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1984-09-28 | 1985-03-30 | 1985-09-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1988-09-28 | 1989-03-30 | 1989-09-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1992-09-28 | 1993-03-30 | 1993-09-29 | $7700.00 | Window Closed / Lapsed |