CA2164239A1 - Treatment of aqueous effluents containing fats and oils - Google Patents
Treatment of aqueous effluents containing fats and oilsInfo
- Publication number
- CA2164239A1 CA2164239A1 CA 2164239 CA2164239A CA2164239A1 CA 2164239 A1 CA2164239 A1 CA 2164239A1 CA 2164239 CA2164239 CA 2164239 CA 2164239 A CA2164239 A CA 2164239A CA 2164239 A1 CA2164239 A1 CA 2164239A1
- Authority
- CA
- Canada
- Prior art keywords
- effluent
- oils
- solution
- fats
- hydrocyclone
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Abandoned
Links
Landscapes
- Separation Of Suspended Particles By Flocculating Agents (AREA)
- Physical Water Treatments (AREA)
Abstract
A process for the treatment of aqueous effluent containing at least one of fats and oils is disclosed.
The process comprises (a) removing particulate matter from the aqueous effluent using at least one hydrocyclone cleaner; (b) feeding solution from (a) to a pressurized flotation apparatus in which the solution is subjected to high pressure aeration and intensive mixing, and thereafter separating aqueous solution from aerated particulate matter; and (c) separating low density matter from the solution from (b) using at least one hydrocyclone cleaner. Water with a lower level of fats and oils than the effluent fed to the process is obtained.
The process comprises (a) removing particulate matter from the aqueous effluent using at least one hydrocyclone cleaner; (b) feeding solution from (a) to a pressurized flotation apparatus in which the solution is subjected to high pressure aeration and intensive mixing, and thereafter separating aqueous solution from aerated particulate matter; and (c) separating low density matter from the solution from (b) using at least one hydrocyclone cleaner. Water with a lower level of fats and oils than the effluent fed to the process is obtained.
Description
216423~
TITLE
T~ENT OF AQUEOU8 EFFLUENT8 FIELD OF THE INVENTION
The present invention relates to a process for the treatment of aqueous effluents containing at least one of fats and oils. In particular, the present invention relates to a process for the treatment of aqueous effluents from the vegetable and food processing industries, from laundry operations, automotive industries, industrial operations and the like.
BACKGROUND TO THE I~V~:N'l'lON
A number of industries discharge waste water cont~in;ng fats and oils, including the food processing industry. In many instances, it has been common practice to discharge such waste water directly to sewage, with any processing of the waste water to an acceptable level of contaminants for the environment being carried out by governmental authorities. However, increasing concerns about the environment are leading to more strict regulations on the quality of water that may be discharged into sewers, rivers or other outlets. The sources of waste water containing fats and oils tends to be localized to a particular manufacturing site, with such manufacturing sites being scattered over an area.
It is unusual to find that one particular area has a very heavy concentration of sites producing waste water containing fats and oils. Thus, it becomes important that each manufacturing site be capable of treating its effluent prior to discharge into sewers or the like. It is generally not practical to feed effluents containing fats and oils from several manufacturing sites to one 216~3~
location i.e. a central location, for treatment of the effluent.
A number of processes have been described in the art for treating effluents containing fats and oils.
For example, in Canadian Patent 1,149,290, which issued July 05, 1983, K. Watanabe et al. describe a process for treating waste water from refining processes of vegetables fats and oils using a semi-permeable membrane. U.S. 5,167,829 of H. Diamond et al describes a method of purifying laundry-type effluents containing fats, oils and greases by using an acidification process.
SU~IARY OF THE I-NV~;N'1'10N
A process for the treatment of aqueous effluents contA;ning at least one of fats and oils using aeration and intensive mixing has now been found.
Accordingly, one aspect of the present invention provides a process for the treatment of aqueous effluent containing at least one of fats and oils comprising:
(a) removing particulate matter from the aqueous effluent using at least one hydrocyclone cleaner;
(b) feeding solution from (a) to a pressurized flotation apparatus in which the solution is subjected to high pressure aeration and intensive mixing, and thereafter separating aqueous solution from aerated particulate matter; and (c) separating lightweight matter from the solution from (b) using at least one hydrocyclone cleaner, thereby providing water with a lower level of fats and oils than the effluent fed to the process.
In an embodiment of the process of the present invention, the solution fed to the pressurized flotation apparatus contains surfactants.
In a further embodiment, hydrocyclone cleaners are used in step (a) to remove at least one of heavy particulate matter and lightweight particulate matter.
In yet another embodiment, subsequent to step (a) but prior to step (b), the effluent is subjected to an acidifying agent or to a flocculating agent and subsequently lightweight matter is skimmed from the surface of the effluent.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be described with particular reference to the embodiment shown in the drawing in which:
FIG. 1 is a schematic representation of the process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a process generally indicated by 1.
Process 1 has an effluent inlet 2 to holding tank 3.
The purpose of holding tank 3 is to provide some consistency in the rate of flow of effluent to the process; other means of regulating the flow of effluent in the process could be used. Effluent passes from holding tank 3 through feed line 4 to pump 5 and then to hydrocyclone inlet 6. This hydrocyclone is a hydrocyclone intended for the removal of contaminants in the effluent being processed. Such contaminants could be heavy contaminants and/or lightweight contaminants, and hydrocyclones could be used to remove one or both types of contaminants. Examples of hydrocyclones are given below. The process would normally not use just one such hydrocyclone, but would use a plurality of 216~2~9 hydrocyclones in series, which could all be of one type or a combination of types. For example, a typical process may use from 5 to 20 hydrocyclones in series, but it is to be understood that the number of hydrocyclones will depend in particular on the nature of the effluent being fed and processed. Contaminants are discharged from the hydrocyclone through discharge 7.
Solution passing from the hydrocyclone is fed through feedline 8 to pressurized flotation apparatus 9.
In pressurized flotation apparatus 9, the effluent is subjected to high pressure aeration and to intensive mixing. Aerated particles are discharged from pressurized flotation apparatus g through aerated discharge 10.
Solution passing from pressurized flotation apparatus 9 is passed through aerated outlet 11 and fed to hydrocyclone inlet 12. This hydrocyclone, 13, is intended to remove lightweight matter (also referred to as light matter or low density matter) from the solution passing from aerated outlet 11. The low density discharge is passed from hydrocyclone 13 through hydrocyclone reject outlet 14. Processed and purified water passes from hydrocyclone 13 through outlet line 15. Again, it is to be understood that hydrocyclone 13 would normally be a plurality of hydrocyclones intended for the removal of lightweight particular matter. From 5 to about 20 such hydrocyclones could be used in series, but it is to be understood that the number of such hydrocyclones will depend in particular on the nature of the effluent being treated.
An example of a hydrocyclone used for the removal of heavy contaminants is a Beloit Jones Posiflow Cleaner, which is available from the Beloit Jones Division of Beloit Corporation, Dalton, Mass., U.S.A.
Posiflow Cleaners are stated to be low pressure drop, 216~23g high efficient fine cleaners for removal of heavy weight debris from solutions. Typical Posiflow Cleaner reject rates are stated to be in the range of 1-3% by volume and 4-6% by weight.
An example of a hydrocyclone for the removal of lightweight particulate matter is a Beloit Jones Uniflow Cleaner, from Beloit Jones Division of Beloit Corporation. A Uniflow Cleaner hydrocyclone is stated to have a low level of bulk flow reversal within the hydrocyclone, a low level of recrossing of fluid stream lines and a low level of leakage or short circuiting of particles within the hydrocyclone, all of which are advantageous to the separation of lightweight particular matter.
An example of a pressurized flotation apparatus is an apparatus known as a Pressurized Deinking Module (PDM) which is also available from the Beloit Jones Division of Beloit Corporation. It is stated that there are three separate stages within the PDM, firstly involving high pressure aeration to produce a wide spectrum of air bubbles which are introduced into a chamber within the apparatus, secondly a dedicated intensive mixing that maximizes the frequency of collisions with particles and air bubbles within the apparatus, and finally a separation zone in which particles are carried away in the rejects.
As noted above, solution passing from the hydrocyclones may be fed through feed line 8 to a separate vessel prior to being fed to pressurized flotation apparatus 9. In this vessel, the solution may be treated to crack or flocculate the greases and oils so that they separate from the solution. For instance, an acid may be added to the effluent to reduce the pH of the solution e.g. to reduce to pH from alkaline values to acidic values, and thereby cause the greases and oils to form a suspension or other lightweight matter which can then be skimmed or otherwise removed from the solution prior to the solution being fed to pressurized flotation apparatus 9. Alternatively the solution could be treated with a polymer that will cause flocculation of the greases and oils. The resultant flocculated greases and oils can then be skimmed or otherwise removed from the solution prior to feeding the solution to pressurized flotation apparatus 9.
In a preferred emhoAiment of the invention, the effluent fed to the pressurized flotation apparatus contains a surfactant, especially to form a foam (suds) in the solution in the pressurized flotation apparatus.
Non-ionic surfactant or ionic surfactants may be used.
The effluent fed to the process may have a broad range of pH. For example, the pH may vary from about 3 to about 10. It is preferred that the treated effluent be substantially neutral i.e. have a pH in the range of 6-8. The latter is primarily determined by governmental regulations.
In its overall context, the present invention will permit a method for the treatment of aqueous effluents containing at least one of fats and oils. The treated effluent could be recycled back into the process from which it was derived or the treated effluent could be sent to sewage in compliance with local regulations.
The rejected matter from the process could be subjected to other treatment processes to provide waste of acceptable properties.
The effluent treated according to the process of the invention could be obtained from the food processing industry, laundry cleaning operations, automotive and other industrial operations that have effluent containing fats and oils. The latter may be vegetable or mineral oils.
216~23!~
The effluent fed to the process may have a wide range of amounts of fats and oils. Examples of amounts are given in the examples hereinafter. If higher amounts are fed to the process, water could be added prior to the treatment steps if it is believed that this would result in more efficient operation of the process.
If the solution passing from the process has too high a level of fats and oils for governmental regulations, then all or part of the effluent could be recycled and/or used as a feed effluent to another treatment process of the type described herein. However, it will be noted from the examples herein that major reductions in the amount of fats and oils in effluent are obtainable according to the present invention.
The method is particularly intended for the treatment of fats and oils in effluents derived from the vegetable and food processing industries.
The present invention is illustrated by the following examples.
EXAMPLE I
Effluent from an industrial laundry facility was fed to a hydrocyclone for removal of heavy contaminants.
The outlet from the hydrocyclone was fed to a vessel to which was added sulphuric acid to reduce the pH of the effluent from a value of about 10 to a value of less than 2. Fats and oils that separated from the aqueous solution were removed by skimming the surface of the solution. The solution was then fed to a pressurized flotation apparatus and then to a hydrocyclone for removal of lightweight contaminants. The resulting effluent, with a pH that had been adjusted to be in the range of 5.5-9.5, was then fed to the sewer.
Further process details and the results obtained are shown in Table I.
TABLE I
216~23~
Run Effluent Effluent Discharge Discharge No. Fats/Oils Solids Fats/Oils Solids (ppm) (ppm) (ppm) (ppm) The results show that a major reduction in the amount of fats and oils and in the amount of suspended solids may be obtained according to the process of the invention.
EXAMPLE II
- Effluent from an industrial laundry facility was fed to a hydrocyclone for removal of heavy contaminants.
The outlet from the hydrocyclone was fed to a vessel to which was added a flocculating agent. Fats and oils that separated from the aqueous solution were removed by skimming the surface of the solution. The solution was then fed to a pressurized flotation apparatus and then to a hydrocyclone for removal of light weight contaminants. The resulting effluent, with a pH that had been adjusted to be in the range of 5.5-9.5, was then fed to the sewer.
Further process details and the results obtained are shown in Table I.
TABLE II
Run Effluent Effluent Discharge Discharge No. Fats/Oils Solids Fats/Oils Solids (ppm) (ppm) (ppm) (ppm) The results show that a major reduction in the amount of fats and oils and in the amount of suspended solids may be obtained according to the process of the invention.
TITLE
T~ENT OF AQUEOU8 EFFLUENT8 FIELD OF THE INVENTION
The present invention relates to a process for the treatment of aqueous effluents containing at least one of fats and oils. In particular, the present invention relates to a process for the treatment of aqueous effluents from the vegetable and food processing industries, from laundry operations, automotive industries, industrial operations and the like.
BACKGROUND TO THE I~V~:N'l'lON
A number of industries discharge waste water cont~in;ng fats and oils, including the food processing industry. In many instances, it has been common practice to discharge such waste water directly to sewage, with any processing of the waste water to an acceptable level of contaminants for the environment being carried out by governmental authorities. However, increasing concerns about the environment are leading to more strict regulations on the quality of water that may be discharged into sewers, rivers or other outlets. The sources of waste water containing fats and oils tends to be localized to a particular manufacturing site, with such manufacturing sites being scattered over an area.
It is unusual to find that one particular area has a very heavy concentration of sites producing waste water containing fats and oils. Thus, it becomes important that each manufacturing site be capable of treating its effluent prior to discharge into sewers or the like. It is generally not practical to feed effluents containing fats and oils from several manufacturing sites to one 216~3~
location i.e. a central location, for treatment of the effluent.
A number of processes have been described in the art for treating effluents containing fats and oils.
For example, in Canadian Patent 1,149,290, which issued July 05, 1983, K. Watanabe et al. describe a process for treating waste water from refining processes of vegetables fats and oils using a semi-permeable membrane. U.S. 5,167,829 of H. Diamond et al describes a method of purifying laundry-type effluents containing fats, oils and greases by using an acidification process.
SU~IARY OF THE I-NV~;N'1'10N
A process for the treatment of aqueous effluents contA;ning at least one of fats and oils using aeration and intensive mixing has now been found.
Accordingly, one aspect of the present invention provides a process for the treatment of aqueous effluent containing at least one of fats and oils comprising:
(a) removing particulate matter from the aqueous effluent using at least one hydrocyclone cleaner;
(b) feeding solution from (a) to a pressurized flotation apparatus in which the solution is subjected to high pressure aeration and intensive mixing, and thereafter separating aqueous solution from aerated particulate matter; and (c) separating lightweight matter from the solution from (b) using at least one hydrocyclone cleaner, thereby providing water with a lower level of fats and oils than the effluent fed to the process.
In an embodiment of the process of the present invention, the solution fed to the pressurized flotation apparatus contains surfactants.
In a further embodiment, hydrocyclone cleaners are used in step (a) to remove at least one of heavy particulate matter and lightweight particulate matter.
In yet another embodiment, subsequent to step (a) but prior to step (b), the effluent is subjected to an acidifying agent or to a flocculating agent and subsequently lightweight matter is skimmed from the surface of the effluent.
BRIEF DESCRIPTION OF THE DRAWING
The present invention will be described with particular reference to the embodiment shown in the drawing in which:
FIG. 1 is a schematic representation of the process of the invention.
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 shows a process generally indicated by 1.
Process 1 has an effluent inlet 2 to holding tank 3.
The purpose of holding tank 3 is to provide some consistency in the rate of flow of effluent to the process; other means of regulating the flow of effluent in the process could be used. Effluent passes from holding tank 3 through feed line 4 to pump 5 and then to hydrocyclone inlet 6. This hydrocyclone is a hydrocyclone intended for the removal of contaminants in the effluent being processed. Such contaminants could be heavy contaminants and/or lightweight contaminants, and hydrocyclones could be used to remove one or both types of contaminants. Examples of hydrocyclones are given below. The process would normally not use just one such hydrocyclone, but would use a plurality of 216~2~9 hydrocyclones in series, which could all be of one type or a combination of types. For example, a typical process may use from 5 to 20 hydrocyclones in series, but it is to be understood that the number of hydrocyclones will depend in particular on the nature of the effluent being fed and processed. Contaminants are discharged from the hydrocyclone through discharge 7.
Solution passing from the hydrocyclone is fed through feedline 8 to pressurized flotation apparatus 9.
In pressurized flotation apparatus 9, the effluent is subjected to high pressure aeration and to intensive mixing. Aerated particles are discharged from pressurized flotation apparatus g through aerated discharge 10.
Solution passing from pressurized flotation apparatus 9 is passed through aerated outlet 11 and fed to hydrocyclone inlet 12. This hydrocyclone, 13, is intended to remove lightweight matter (also referred to as light matter or low density matter) from the solution passing from aerated outlet 11. The low density discharge is passed from hydrocyclone 13 through hydrocyclone reject outlet 14. Processed and purified water passes from hydrocyclone 13 through outlet line 15. Again, it is to be understood that hydrocyclone 13 would normally be a plurality of hydrocyclones intended for the removal of lightweight particular matter. From 5 to about 20 such hydrocyclones could be used in series, but it is to be understood that the number of such hydrocyclones will depend in particular on the nature of the effluent being treated.
An example of a hydrocyclone used for the removal of heavy contaminants is a Beloit Jones Posiflow Cleaner, which is available from the Beloit Jones Division of Beloit Corporation, Dalton, Mass., U.S.A.
Posiflow Cleaners are stated to be low pressure drop, 216~23g high efficient fine cleaners for removal of heavy weight debris from solutions. Typical Posiflow Cleaner reject rates are stated to be in the range of 1-3% by volume and 4-6% by weight.
An example of a hydrocyclone for the removal of lightweight particulate matter is a Beloit Jones Uniflow Cleaner, from Beloit Jones Division of Beloit Corporation. A Uniflow Cleaner hydrocyclone is stated to have a low level of bulk flow reversal within the hydrocyclone, a low level of recrossing of fluid stream lines and a low level of leakage or short circuiting of particles within the hydrocyclone, all of which are advantageous to the separation of lightweight particular matter.
An example of a pressurized flotation apparatus is an apparatus known as a Pressurized Deinking Module (PDM) which is also available from the Beloit Jones Division of Beloit Corporation. It is stated that there are three separate stages within the PDM, firstly involving high pressure aeration to produce a wide spectrum of air bubbles which are introduced into a chamber within the apparatus, secondly a dedicated intensive mixing that maximizes the frequency of collisions with particles and air bubbles within the apparatus, and finally a separation zone in which particles are carried away in the rejects.
As noted above, solution passing from the hydrocyclones may be fed through feed line 8 to a separate vessel prior to being fed to pressurized flotation apparatus 9. In this vessel, the solution may be treated to crack or flocculate the greases and oils so that they separate from the solution. For instance, an acid may be added to the effluent to reduce the pH of the solution e.g. to reduce to pH from alkaline values to acidic values, and thereby cause the greases and oils to form a suspension or other lightweight matter which can then be skimmed or otherwise removed from the solution prior to the solution being fed to pressurized flotation apparatus 9. Alternatively the solution could be treated with a polymer that will cause flocculation of the greases and oils. The resultant flocculated greases and oils can then be skimmed or otherwise removed from the solution prior to feeding the solution to pressurized flotation apparatus 9.
In a preferred emhoAiment of the invention, the effluent fed to the pressurized flotation apparatus contains a surfactant, especially to form a foam (suds) in the solution in the pressurized flotation apparatus.
Non-ionic surfactant or ionic surfactants may be used.
The effluent fed to the process may have a broad range of pH. For example, the pH may vary from about 3 to about 10. It is preferred that the treated effluent be substantially neutral i.e. have a pH in the range of 6-8. The latter is primarily determined by governmental regulations.
In its overall context, the present invention will permit a method for the treatment of aqueous effluents containing at least one of fats and oils. The treated effluent could be recycled back into the process from which it was derived or the treated effluent could be sent to sewage in compliance with local regulations.
The rejected matter from the process could be subjected to other treatment processes to provide waste of acceptable properties.
The effluent treated according to the process of the invention could be obtained from the food processing industry, laundry cleaning operations, automotive and other industrial operations that have effluent containing fats and oils. The latter may be vegetable or mineral oils.
216~23!~
The effluent fed to the process may have a wide range of amounts of fats and oils. Examples of amounts are given in the examples hereinafter. If higher amounts are fed to the process, water could be added prior to the treatment steps if it is believed that this would result in more efficient operation of the process.
If the solution passing from the process has too high a level of fats and oils for governmental regulations, then all or part of the effluent could be recycled and/or used as a feed effluent to another treatment process of the type described herein. However, it will be noted from the examples herein that major reductions in the amount of fats and oils in effluent are obtainable according to the present invention.
The method is particularly intended for the treatment of fats and oils in effluents derived from the vegetable and food processing industries.
The present invention is illustrated by the following examples.
EXAMPLE I
Effluent from an industrial laundry facility was fed to a hydrocyclone for removal of heavy contaminants.
The outlet from the hydrocyclone was fed to a vessel to which was added sulphuric acid to reduce the pH of the effluent from a value of about 10 to a value of less than 2. Fats and oils that separated from the aqueous solution were removed by skimming the surface of the solution. The solution was then fed to a pressurized flotation apparatus and then to a hydrocyclone for removal of lightweight contaminants. The resulting effluent, with a pH that had been adjusted to be in the range of 5.5-9.5, was then fed to the sewer.
Further process details and the results obtained are shown in Table I.
TABLE I
216~23~
Run Effluent Effluent Discharge Discharge No. Fats/Oils Solids Fats/Oils Solids (ppm) (ppm) (ppm) (ppm) The results show that a major reduction in the amount of fats and oils and in the amount of suspended solids may be obtained according to the process of the invention.
EXAMPLE II
- Effluent from an industrial laundry facility was fed to a hydrocyclone for removal of heavy contaminants.
The outlet from the hydrocyclone was fed to a vessel to which was added a flocculating agent. Fats and oils that separated from the aqueous solution were removed by skimming the surface of the solution. The solution was then fed to a pressurized flotation apparatus and then to a hydrocyclone for removal of light weight contaminants. The resulting effluent, with a pH that had been adjusted to be in the range of 5.5-9.5, was then fed to the sewer.
Further process details and the results obtained are shown in Table I.
TABLE II
Run Effluent Effluent Discharge Discharge No. Fats/Oils Solids Fats/Oils Solids (ppm) (ppm) (ppm) (ppm) The results show that a major reduction in the amount of fats and oils and in the amount of suspended solids may be obtained according to the process of the invention.
Claims (6)
1. A process for the treatment of aqueous effluent containing at least one of fats and oils comprising:
(a) removing particulate matter from the aqueous effluent using at least one hydrocyclone cleaner;
(b) feeding solution from (a) to a pressurized flotation apparatus in which the solution is subjected to high pressure aeration and intensive mixing, and thereafter separating aqueous solution from aerated particulate matter; and (c) separating lightweight matter from the solution from (b) using at least one hydrocyclone cleaner, thereby providing water with a lower level of fats and oils than the effluent fed to the process.
(a) removing particulate matter from the aqueous effluent using at least one hydrocyclone cleaner;
(b) feeding solution from (a) to a pressurized flotation apparatus in which the solution is subjected to high pressure aeration and intensive mixing, and thereafter separating aqueous solution from aerated particulate matter; and (c) separating lightweight matter from the solution from (b) using at least one hydrocyclone cleaner, thereby providing water with a lower level of fats and oils than the effluent fed to the process.
2. The process of Claim 1 in which the solution fed to the pressurized flotation apparatus contains a surfactant.
3. The process of Claim 1 or Claim 2 in which hydrocyclone cleaners are used in step (a) to remove at least one of heavy particulate matter and light particulate matter.
4. The process of any one of Claims 1-3 in which, subsequent to step (a) but prior to step (b), the effluent is subjected to an acidifying agent and subsequently lightweight matter is skimmed from the surface of the effluent.
5. The process of any one of Claims 1-3 in which, subsequent to step (a) but prior to step (b), the effluent is subjected to a flocculating agent and subsequently lightweight matter is skimmed from the surface of the effluent.
6. The process of any one of Claims 1-5 in which the pressurized flotation apparatus is a pressurized de-inking module.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9424333.4 | 1994-12-01 | ||
| GB9424333A GB9424333D0 (en) | 1994-12-01 | 1994-12-01 | Treatment of aqueous effluents containing fats and oils |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA2164239A1 true CA2164239A1 (en) | 1996-06-02 |
Family
ID=10765313
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA 2164239 Abandoned CA2164239A1 (en) | 1994-12-01 | 1995-12-01 | Treatment of aqueous effluents containing fats and oils |
Country Status (2)
| Country | Link |
|---|---|
| CA (1) | CA2164239A1 (en) |
| GB (1) | GB9424333D0 (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0978482A1 (en) * | 1998-08-07 | 2000-02-09 | Sergio Rappini Gherardi | Machine for treating wastewater by centrifugal separation and flotation |
| ES2239872A1 (en) * | 2003-02-19 | 2005-10-01 | Felice Gugliel. Nola | Wastewater purification apparatus |
| RU2800672C1 (en) * | 2022-10-12 | 2023-07-25 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Российский государственный геологоразведочный университет имени Серго Орджоникидзе" | Method for purification of oily wastewater in convective flows |
-
1994
- 1994-12-01 GB GB9424333A patent/GB9424333D0/en active Pending
-
1995
- 1995-12-01 CA CA 2164239 patent/CA2164239A1/en not_active Abandoned
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0978482A1 (en) * | 1998-08-07 | 2000-02-09 | Sergio Rappini Gherardi | Machine for treating wastewater by centrifugal separation and flotation |
| ES2239872A1 (en) * | 2003-02-19 | 2005-10-01 | Felice Gugliel. Nola | Wastewater purification apparatus |
| RU2800672C1 (en) * | 2022-10-12 | 2023-07-25 | Федеральное государственное бюджетное образовательное учреждение высшего образования "Российский государственный геологоразведочный университет имени Серго Орджоникидзе" | Method for purification of oily wastewater in convective flows |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9424333D0 (en) | 1995-01-18 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| FZDE | Dead |