CA1263769A - Water treatment method and apparatus - Google Patents
Water treatment method and apparatusInfo
- Publication number
- CA1263769A CA1263769A CA000564330A CA564330A CA1263769A CA 1263769 A CA1263769 A CA 1263769A CA 000564330 A CA000564330 A CA 000564330A CA 564330 A CA564330 A CA 564330A CA 1263769 A CA1263769 A CA 1263769A
- Authority
- CA
- Canada
- Prior art keywords
- water
- gas
- water treatment
- oxygen
- treatment method
- 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.)
- Expired
Links
Classifications
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F3/00—Biological treatment of water, waste water, or sewage
- C02F3/02—Aerobic processes
- C02F3/12—Activated sludge processes
- C02F3/1278—Provisions for mixing or aeration of the mixed liquor
- C02F3/1294—"Venturi" aeration means
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F1/00—Treatment of water, waste water, or sewage
- C02F1/72—Treatment of water, waste water, or sewage by oxidation
- C02F1/725—Treatment of water, waste water, or sewage by oxidation by catalytic oxidation
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W10/00—Technologies for wastewater treatment
- Y02W10/10—Biological treatment of water, waste water, or sewage
Landscapes
- Life Sciences & Earth Sciences (AREA)
- Chemical & Material Sciences (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Biodiversity & Conservation Biology (AREA)
- Microbiology (AREA)
- Treatment Of Water By Oxidation Or Reduction (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A method is disclosed for the treatment of contaminated water, which comprises the steps of introducing a predetermined quantity of air, oxygen or other oxygen-containing gas into the water to be treated, maintaining the air and water under pressure and applying centrifugal force thereto thus introducing a carbonation effect which facilitates oxidation of contaminants in the water and resultant precipitation thereof in particulate form, separating the oxidized particles from the water by filtration, and recovering the treated water. An apparatus is provided for the implementation of the method.
A method is disclosed for the treatment of contaminated water, which comprises the steps of introducing a predetermined quantity of air, oxygen or other oxygen-containing gas into the water to be treated, maintaining the air and water under pressure and applying centrifugal force thereto thus introducing a carbonation effect which facilitates oxidation of contaminants in the water and resultant precipitation thereof in particulate form, separating the oxidized particles from the water by filtration, and recovering the treated water. An apparatus is provided for the implementation of the method.
Description
~2637~9 This invention relates to a method and apparatus for the treatment of contaminated water, in particular water which is contaminated by oxidizable substances such as ferrous iron, ferric iron, manganese and hydrogen sulphide.
The use of aeration processes in the removal of contaminants from water is known, with the intended result being the oxidation of such contaminants. Traditional methods involve the use of either an open system, in which the water i5 sprayed into the air or allowed to flow or trickle down over cascades or similar obstructions; or a closed system, in which air is forced under pressure into a closed empty tank through which the water is flowing.
Other existing methods in general use a static mixer in order to achieve the oxidation, which has the disadvantage of low efficiency, and of requiring air venting to release excess air. E~uipment required for such methods is relatively complex to manufacture, and tends not to remove a satisfactory quantity of contaminants.
United States Patent No. 3,521,752 (William Edward Lindman) describes a water purification system in which a gaseous mixture containing sulfur dloxide and oxygen i~ passed through the water which is then violently agitated. The apparatus include~ means for adding scrap lron to the water being treated.
United States Patent No. 3,649,53Z ~John Oliver McLean) discloses a method of treating water in a one-tank system, to remove iron and reduce acidity, by adding air to the water to precipitate iron and raising the pH of the water while filtering iron hydroxide therefrom by passing air and water thus mixed through a mineral bed.
United States Patent No. 4,430,228 ~aurence 0.
Paterson) relates to the removal of iron compounds from water by aerating the water in an in~ection-mixer, maintaining the aerated water under pressure and then passing the water through particulate material having a surface charge capable of attracting and removing dispersed iron hydrates from the water.
12~37~
United States Patent No. 4,534,867 (Edward D.
Kreusch et al) desçribes a similar system for removing iron or other chemically reducing substances from potable water, including a tank containing a bed of activated 5carbon. Untreated water is first aerated and then permitted to flow through the bed to permit the activated carbon to provide a catalytic action and oxidize the iron in the water. The precipitated oxidized particles are retained in the bed by a filtration effect thereof.
10United States Patent No. 4,695,3~8 (Terry E.
Ackman et al) discloses a water aeration and treatment system in which a ~et pump is employed to effect aeration of the water to be treated, using atmospheric air. The water discharged from the jet pump then enters a static 15mixer to provide further aeration of the waste water.
Other methods of removal of contaminants require the use of chemicals, which gives rise to the disadvantages of cost and of environmental or other problems. Most existing systems require regular time 20consuming maintenance for their operation.
An object of this invention therefore is to provide a method of removal of contaminants from water which has increased efficiency, little maintenance, avoids chemical use, and is simple to construct and operate.
25Accordingly, one aspect of the invention provides a method for the treatment of contaminated water, which comprises:
(1) introducing a predetermined quantity of oxygen containing gas, such as air, oxygen or a mixture 30thereof, into the water to be treated;
The use of aeration processes in the removal of contaminants from water is known, with the intended result being the oxidation of such contaminants. Traditional methods involve the use of either an open system, in which the water i5 sprayed into the air or allowed to flow or trickle down over cascades or similar obstructions; or a closed system, in which air is forced under pressure into a closed empty tank through which the water is flowing.
Other existing methods in general use a static mixer in order to achieve the oxidation, which has the disadvantage of low efficiency, and of requiring air venting to release excess air. E~uipment required for such methods is relatively complex to manufacture, and tends not to remove a satisfactory quantity of contaminants.
United States Patent No. 3,521,752 (William Edward Lindman) describes a water purification system in which a gaseous mixture containing sulfur dloxide and oxygen i~ passed through the water which is then violently agitated. The apparatus include~ means for adding scrap lron to the water being treated.
United States Patent No. 3,649,53Z ~John Oliver McLean) discloses a method of treating water in a one-tank system, to remove iron and reduce acidity, by adding air to the water to precipitate iron and raising the pH of the water while filtering iron hydroxide therefrom by passing air and water thus mixed through a mineral bed.
United States Patent No. 4,430,228 ~aurence 0.
Paterson) relates to the removal of iron compounds from water by aerating the water in an in~ection-mixer, maintaining the aerated water under pressure and then passing the water through particulate material having a surface charge capable of attracting and removing dispersed iron hydrates from the water.
12~37~
United States Patent No. 4,534,867 (Edward D.
Kreusch et al) desçribes a similar system for removing iron or other chemically reducing substances from potable water, including a tank containing a bed of activated 5carbon. Untreated water is first aerated and then permitted to flow through the bed to permit the activated carbon to provide a catalytic action and oxidize the iron in the water. The precipitated oxidized particles are retained in the bed by a filtration effect thereof.
10United States Patent No. 4,695,3~8 (Terry E.
Ackman et al) discloses a water aeration and treatment system in which a ~et pump is employed to effect aeration of the water to be treated, using atmospheric air. The water discharged from the jet pump then enters a static 15mixer to provide further aeration of the waste water.
Other methods of removal of contaminants require the use of chemicals, which gives rise to the disadvantages of cost and of environmental or other problems. Most existing systems require regular time 20consuming maintenance for their operation.
An object of this invention therefore is to provide a method of removal of contaminants from water which has increased efficiency, little maintenance, avoids chemical use, and is simple to construct and operate.
25Accordingly, one aspect of the invention provides a method for the treatment of contaminated water, which comprises:
(1) introducing a predetermined quantity of oxygen containing gas, such as air, oxygen or a mixture 30thereof, into the water to be treated;
(2) maintaining the gas and water under pre~sure and applying centrifugal force thereto causing carbonation thereof facilitating the oxidation of contaminants in the water and resulting in precipitation 35of the contaminants in particulate form;
(3) separating said oxidized particles from the water by filtration; and
(4) recovering the treated water.
1:~6~7~;~
Another aspect of the invention provides an apparatus ~or the treatment of contaminated water comprisina a mixing chamber. a water input line communicating with said chamber, pump means capable of introducing oxygen-containing gas into said chamber, pressure means for maintaining the contents of said chamber under pressure. mixer means capable of application of centrifugal force to a pressurlzed water and gas mixture in said chamber so as to produce a carbonation to effect oxidation of contaminants in the water, filtration means capable of separating precipitated particulate conta~inants from the water after the application of centrifugal force thereto, and means for recover~ng the treated water.
The chemlcal reaction which takes place during the oxidation process may be illustrated by the following equation:
2 Fe tHC08)2 + ~2 2 Fe (OH)3 particles + 4 ~2 ga8 This oxidation takes place rapidly at a pH of about 6.5 and almost immediately in the higher pH range of normally alkaline natural water. The end product is ferric hydroxide which in particular precipltates easily, settles in a retention chamber or can be filtered out by normal sediment filtration. The carbon dioxide being a 26 gas, when released, escapes into the atmosphere. The resulting pH of the water is, of course, higher, and thus corrosion by carbonic acid is reduced.
In the above chemical equation, it can be seen only one atom of oxygen is needed to oxidize two atoms of ferrous iron, with a valence of 2, to ferric iron, with a valence of 3. The atomic weight of oxygen is 16, that of iron 55.8, thus, 16 ppm of oxygen will oxidize 2 x 55.8 =
111.6 ppm of iron, or 1 ppm of ferrous iron will require only 1/7 ppm of oxygen to oxidize it. Water in contact with air will dissolve 12.5 ppm of oxygen at 5C, 10.2 ppm at 15C, and 8.4 ppm at 25C. The lower the temperature, the higher the solubility. Water saturated with even 8.4 ppm of oxygen can oxidize about 8.4 x 7 = 58.8 ppm of ~.2~i376~
ferrous iron found in any but the most exceptional normally alkaline waters.
Thus, the invention utilize~ an in-line air inducer using the water line pressure to draw room air into the water stream containing the iron, manganese, and H2S, thus achieving an air-water mix and oxidation. The oxidation is then further expanded, enhanced and accelerated by means of a centrifugal in-line mixer resulting in a final air-water mix solution.
Because of this, there is no excess of air in the system, and the oxidation is lOOX complete. There are many ways of introducing air into the water stream including through venturi or air compression. ~he pre~ent 8y8tem does not rely on the manner of introducing the air, but on how to attain total mixing of the air with every portion of water to achieve the complete oxidation process.
For example, the use of the system of the invention enables recovery of treated water with oxidizable contaminants removed to a level of less than 0.1 mg/l of iron, less than 0.05 mg/l of manganese, and hydrogen sulfide at a non-detectable level, commencing from contaminated water, for example containing dissolved iron in an amount of about 40.0 mg~l, dissolved manganese in an amount of about 8.00 mg/l and a hydrogen sulfide content of about 3.0 mg/l.
~mbodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 show~ a schematlc partly cros~
sectional view of an apparatus embodyin~ the invention;
and Figure 2 shows a partly cross sect ional view of an embodiment of mixer.
Referring now to Figure 1, the apparatus comprises an input supply conduit 1 leading to a strainer 2, which prevents particles larger than about 1 mm from pa~sing. The strainer 2 leads, in turn, to an air 1263~9 injector 6 attached by suitable means to the conduit 1.
The in~ector 6 can be any suitable pump means, but preferably includes a venturi 6A, and has connected thereto ~n air input conduit 4 leading from a ~creen 3.
An air flow monitor 5 i5 attached to the conduit 4. At the air injector 6, ad~ustment ~crews ~A and ~B provide adJustment means for the air and water flow~. From the in~ector 6, a conduit 8 leads to a centrifugal mixer 9, which is described in greater detail below.
From the mixer 9, conduit 10 leads to a filtration unit 13, the entry thereto being regulated by valves 12 and 20. The conduit 10 terminate~ in~ide the filtration unit 13 ~n an upper screen 14, located in a free zone 15 within the filtration unit 13. In the lower portion of the unit 13, filter medium 16 i8 d~posed. The medium 16 can be any suitable catalytic filter, but is preferably BI~M , which is manufactured by Clack Corporation of Windsor, Wi~consin, USA, or a catalytic sand. Other suitable filter material~ include, silica sand, aridsorb, activated carbon, greensand and Filter-Ag . From a point near the bot~om of ~he unit 13, a conduit 18, havin~ an entry screen 1~, leads upwards through the unit 13 to an exit point at-~he top thereof, and thence through valve 19 and conduit l9A to a water outlet ~not shown).
The embodiment shown i8 also provided with reverse flow means, by which the filtration unit can be periodically cleansed and restratified. For this purpose, a water ~upply conduit 11 leads into the conduit 10 and thence to valve 20 which can function as an input means to the conduit 18 within the filtration unit 13. Conduit 22 can be used as an exit mean~ controlled by valve 21 to any suitable waste disposal means (not shown), such as a drain.
*Trademark f ~
~.263769 Referring now to Fi~ure 2, a centrifugal mixer 9 is shown which compri~es a cylindrical main tube 23 having an input end 28 and an output end 27. A spiral element 26 ls contained within the main tube 23 along substantially the entire len~th thereof. The main tube 23 ~s encased in a cylindrical sleeve 24, with endcaps 25. The spiral element 26 preferably has an angle of deflection within the range of 2~ to 89 degrees, in order to achieve the best results from the centrifugal force produced by the element 26 on the water and air passing through the mixer 9. The function of the apparatus and its method of operation will now be further de~cribed.
Water which is contaminated by contaminants, such a~ ferrous iron, ferric iron, manganese and hydrogen sulphide, i8 pumped into conduit 1 and through the strainer 2 which separates out any relatively large solid particles having a particle size of about 1 mm or larger.
Room air entering through the screen 3 and monitored by the monitor 5 pa~ses through air conduit 4 into the alr injeotor 6, whlch can be any suitable pump means, but is preferably an air pump, a ~et pump or venturi ~eans. In the embodiment shown, the water flow i~ regulated by an adjustment screw 7A which can provide or prevent a bypass channel around a venturi 6A. The flow of water regulates the ~uction created by the venturi 6A, cau~ing air to enter from conduit 4. The desired air flo~ can be achieved by regulating the ad~ustment crew ~B.
The air and water then pass throu~h conduit 8 into the mixer 9, entering by input conduit 28 and fl~wing around and through the spiral ele~ent 26 within the main tube 23. The effect of the ~piral element 26 i8 to exert a centrifugal force to the water and air which a~sists air to dissolve in the water ~uch a~ to cause a carbonation effect (i.e. a disperson of the oxygen-containing gas into the water). As the mixer i8 pressurized, the carbonation effect is maintained until the water i8 no lon~er under pressure. The flow rate and the system pressure must be lZ~376~
6a sufficient to cause pressure loss over the spiral element 26.
The effects of the carbonation are of ~reat si~nificance to the invention. Firstly, as the air is not released from the mlxture until the pressure is released, there is no necessity for air venting for any excess alr.
,.. ~
1;~637.~
Secondly, the fine division of the air and its even distribution throughout the water maximize the contact of contaminants with the air so as to achieve a high efficiency of the oxidation process.
The result of the oxidation is to convert the contaminants to precipitated particulate matter, which can then be filtered out of the water. The water leaves the mixer unit 9 by conduit 10 and passes to the filtration unit 13, entering through opened valve 12. At this point in the process, valves 20 and 21 are closed. The water and particulate matter pass through upper screen 14 and enter free zone 15 containing the air-water mix, in which any remaining unoxidized contaminants can become oxidized.
The water then passes down through the filter medium 16 to the lower portion of the filtration unit 13.
Such medium 16 operates to separate the particulate matter and any unoxidized solid contaminants from the water. The filtered water can then pass through screen 1~ and rise up through conduit 18 and out of the filtration unit 13, passing through opened valve lg to leave the system for further use.
Periodically, the filter medium 16 may be cleansed and restratified. For this purpose, a reverse flow means can be provided, as shown in Figure 1.
To operate the reverse flow, the valves 12 and 10 are closed, and the valves 20 and 21 are opened. Water is then pumped from a supply (not shown) through conduit 11 and thence into the filtration unit 13 through valve 20 and conduit 18 to the lower portion of the unit 13. The water then rises through the medium 16, cleansing it and restratifying it, before being directed out of the unit 13 by means of conduit 22 through valve 21 to a waste disposal means (not shown), such as a drain. This reverse flow process can be provided as an automatic process.
It should further be noted that the method and apparatus are suitable for use in respect of any contaminants which can be axidized by air, in addition to more common contaminants specifically mentioned herein.
1:~6~7~;~
Another aspect of the invention provides an apparatus ~or the treatment of contaminated water comprisina a mixing chamber. a water input line communicating with said chamber, pump means capable of introducing oxygen-containing gas into said chamber, pressure means for maintaining the contents of said chamber under pressure. mixer means capable of application of centrifugal force to a pressurlzed water and gas mixture in said chamber so as to produce a carbonation to effect oxidation of contaminants in the water, filtration means capable of separating precipitated particulate conta~inants from the water after the application of centrifugal force thereto, and means for recover~ng the treated water.
The chemlcal reaction which takes place during the oxidation process may be illustrated by the following equation:
2 Fe tHC08)2 + ~2 2 Fe (OH)3 particles + 4 ~2 ga8 This oxidation takes place rapidly at a pH of about 6.5 and almost immediately in the higher pH range of normally alkaline natural water. The end product is ferric hydroxide which in particular precipltates easily, settles in a retention chamber or can be filtered out by normal sediment filtration. The carbon dioxide being a 26 gas, when released, escapes into the atmosphere. The resulting pH of the water is, of course, higher, and thus corrosion by carbonic acid is reduced.
In the above chemical equation, it can be seen only one atom of oxygen is needed to oxidize two atoms of ferrous iron, with a valence of 2, to ferric iron, with a valence of 3. The atomic weight of oxygen is 16, that of iron 55.8, thus, 16 ppm of oxygen will oxidize 2 x 55.8 =
111.6 ppm of iron, or 1 ppm of ferrous iron will require only 1/7 ppm of oxygen to oxidize it. Water in contact with air will dissolve 12.5 ppm of oxygen at 5C, 10.2 ppm at 15C, and 8.4 ppm at 25C. The lower the temperature, the higher the solubility. Water saturated with even 8.4 ppm of oxygen can oxidize about 8.4 x 7 = 58.8 ppm of ~.2~i376~
ferrous iron found in any but the most exceptional normally alkaline waters.
Thus, the invention utilize~ an in-line air inducer using the water line pressure to draw room air into the water stream containing the iron, manganese, and H2S, thus achieving an air-water mix and oxidation. The oxidation is then further expanded, enhanced and accelerated by means of a centrifugal in-line mixer resulting in a final air-water mix solution.
Because of this, there is no excess of air in the system, and the oxidation is lOOX complete. There are many ways of introducing air into the water stream including through venturi or air compression. ~he pre~ent 8y8tem does not rely on the manner of introducing the air, but on how to attain total mixing of the air with every portion of water to achieve the complete oxidation process.
For example, the use of the system of the invention enables recovery of treated water with oxidizable contaminants removed to a level of less than 0.1 mg/l of iron, less than 0.05 mg/l of manganese, and hydrogen sulfide at a non-detectable level, commencing from contaminated water, for example containing dissolved iron in an amount of about 40.0 mg~l, dissolved manganese in an amount of about 8.00 mg/l and a hydrogen sulfide content of about 3.0 mg/l.
~mbodiments of the invention will now be described, by way of example, with reference to the accompanying drawings, in which:
Figure 1 show~ a schematlc partly cros~
sectional view of an apparatus embodyin~ the invention;
and Figure 2 shows a partly cross sect ional view of an embodiment of mixer.
Referring now to Figure 1, the apparatus comprises an input supply conduit 1 leading to a strainer 2, which prevents particles larger than about 1 mm from pa~sing. The strainer 2 leads, in turn, to an air 1263~9 injector 6 attached by suitable means to the conduit 1.
The in~ector 6 can be any suitable pump means, but preferably includes a venturi 6A, and has connected thereto ~n air input conduit 4 leading from a ~creen 3.
An air flow monitor 5 i5 attached to the conduit 4. At the air injector 6, ad~ustment ~crews ~A and ~B provide adJustment means for the air and water flow~. From the in~ector 6, a conduit 8 leads to a centrifugal mixer 9, which is described in greater detail below.
From the mixer 9, conduit 10 leads to a filtration unit 13, the entry thereto being regulated by valves 12 and 20. The conduit 10 terminate~ in~ide the filtration unit 13 ~n an upper screen 14, located in a free zone 15 within the filtration unit 13. In the lower portion of the unit 13, filter medium 16 i8 d~posed. The medium 16 can be any suitable catalytic filter, but is preferably BI~M , which is manufactured by Clack Corporation of Windsor, Wi~consin, USA, or a catalytic sand. Other suitable filter material~ include, silica sand, aridsorb, activated carbon, greensand and Filter-Ag . From a point near the bot~om of ~he unit 13, a conduit 18, havin~ an entry screen 1~, leads upwards through the unit 13 to an exit point at-~he top thereof, and thence through valve 19 and conduit l9A to a water outlet ~not shown).
The embodiment shown i8 also provided with reverse flow means, by which the filtration unit can be periodically cleansed and restratified. For this purpose, a water ~upply conduit 11 leads into the conduit 10 and thence to valve 20 which can function as an input means to the conduit 18 within the filtration unit 13. Conduit 22 can be used as an exit mean~ controlled by valve 21 to any suitable waste disposal means (not shown), such as a drain.
*Trademark f ~
~.263769 Referring now to Fi~ure 2, a centrifugal mixer 9 is shown which compri~es a cylindrical main tube 23 having an input end 28 and an output end 27. A spiral element 26 ls contained within the main tube 23 along substantially the entire len~th thereof. The main tube 23 ~s encased in a cylindrical sleeve 24, with endcaps 25. The spiral element 26 preferably has an angle of deflection within the range of 2~ to 89 degrees, in order to achieve the best results from the centrifugal force produced by the element 26 on the water and air passing through the mixer 9. The function of the apparatus and its method of operation will now be further de~cribed.
Water which is contaminated by contaminants, such a~ ferrous iron, ferric iron, manganese and hydrogen sulphide, i8 pumped into conduit 1 and through the strainer 2 which separates out any relatively large solid particles having a particle size of about 1 mm or larger.
Room air entering through the screen 3 and monitored by the monitor 5 pa~ses through air conduit 4 into the alr injeotor 6, whlch can be any suitable pump means, but is preferably an air pump, a ~et pump or venturi ~eans. In the embodiment shown, the water flow i~ regulated by an adjustment screw 7A which can provide or prevent a bypass channel around a venturi 6A. The flow of water regulates the ~uction created by the venturi 6A, cau~ing air to enter from conduit 4. The desired air flo~ can be achieved by regulating the ad~ustment crew ~B.
The air and water then pass throu~h conduit 8 into the mixer 9, entering by input conduit 28 and fl~wing around and through the spiral ele~ent 26 within the main tube 23. The effect of the ~piral element 26 i8 to exert a centrifugal force to the water and air which a~sists air to dissolve in the water ~uch a~ to cause a carbonation effect (i.e. a disperson of the oxygen-containing gas into the water). As the mixer i8 pressurized, the carbonation effect is maintained until the water i8 no lon~er under pressure. The flow rate and the system pressure must be lZ~376~
6a sufficient to cause pressure loss over the spiral element 26.
The effects of the carbonation are of ~reat si~nificance to the invention. Firstly, as the air is not released from the mlxture until the pressure is released, there is no necessity for air venting for any excess alr.
,.. ~
1;~637.~
Secondly, the fine division of the air and its even distribution throughout the water maximize the contact of contaminants with the air so as to achieve a high efficiency of the oxidation process.
The result of the oxidation is to convert the contaminants to precipitated particulate matter, which can then be filtered out of the water. The water leaves the mixer unit 9 by conduit 10 and passes to the filtration unit 13, entering through opened valve 12. At this point in the process, valves 20 and 21 are closed. The water and particulate matter pass through upper screen 14 and enter free zone 15 containing the air-water mix, in which any remaining unoxidized contaminants can become oxidized.
The water then passes down through the filter medium 16 to the lower portion of the filtration unit 13.
Such medium 16 operates to separate the particulate matter and any unoxidized solid contaminants from the water. The filtered water can then pass through screen 1~ and rise up through conduit 18 and out of the filtration unit 13, passing through opened valve lg to leave the system for further use.
Periodically, the filter medium 16 may be cleansed and restratified. For this purpose, a reverse flow means can be provided, as shown in Figure 1.
To operate the reverse flow, the valves 12 and 10 are closed, and the valves 20 and 21 are opened. Water is then pumped from a supply (not shown) through conduit 11 and thence into the filtration unit 13 through valve 20 and conduit 18 to the lower portion of the unit 13. The water then rises through the medium 16, cleansing it and restratifying it, before being directed out of the unit 13 by means of conduit 22 through valve 21 to a waste disposal means (not shown), such as a drain. This reverse flow process can be provided as an automatic process.
It should further be noted that the method and apparatus are suitable for use in respect of any contaminants which can be axidized by air, in addition to more common contaminants specifically mentioned herein.
Claims (19)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method for treatment of contaminated water, which comprises:
introducing an oxygen-containing gas into water to be treated by means of an in-line gas induction system;
maintaining the gas and water under pressure;
flowing the gas/water mixture and subjecting the gas and water to thorough mixing under pressure by centrifugal force created by flow through a spiral core static mixer element, to cause dispersion of the gas in the water and thereby facilitate the oxidation of contaminants in the water by the oxygen-containing gas and resultant precipitation of contaminants in particulate form;
separating said oxidized contaminant particles from the water by filtration; and recovering the treated water.
introducing an oxygen-containing gas into water to be treated by means of an in-line gas induction system;
maintaining the gas and water under pressure;
flowing the gas/water mixture and subjecting the gas and water to thorough mixing under pressure by centrifugal force created by flow through a spiral core static mixer element, to cause dispersion of the gas in the water and thereby facilitate the oxidation of contaminants in the water by the oxygen-containing gas and resultant precipitation of contaminants in particulate form;
separating said oxidized contaminant particles from the water by filtration; and recovering the treated water.
2. A water treatment method as claimed in claim 1, wherein the oxygen-containing gas is air, oxygen or a mixture thereof.
3. A water treatment method as claimed in claim 1, wherein the gas and water are maintained under a pressure within the range of from 10 to 65 psi.
4. A water treatment method as claimed in claim 1, 2 or 3, wherein the centrifugal force produced causes a pressure loss during substantial flow in the range of from 6 to 18 psi.
5. A water treatment method, as claimed in claim 1, 2 or 3, wherein the ratio of the oxygen-containing gas to the amount of contaminated water is at least 1:81.
6. A water treatment method as claimed in claim 1, 2 or 3, wherein filtration is effected by a catalytic filter bed.
7. A water treatment method as claimed in claim 1, 2 or 3, wherein the treated water contains less than 0.1 mg/litre of iron, less than 0.05 mg/litre of manganese and undetectable low levels of hydrogen sulfide.
8. A water treatment method as claimed in claim 1, wherein the introduction of oxygen-containing gas is achieved by means of a venturi tube.
9. An apparatus for the treatment of contaminated water, which comprises:
a water input line, capable of supplying water to be treated under pressure;
an in-line gas induction means capable of introducing oxygen-containing gas into the water;
a mixing chamber communicating with said water input line and capable of thoroughly mixing the gas with the water under pressure as a result of the action of centrifugal force due to the flow of the water in the chamber through a spiral core element, thereby producing a dispersion of the gas in the water so as to effect oxidation of contaminants in the water;
filtration means capable of separating precipitated particulate contaminants from the water after mixing; and means for recovering the treated water.
a water input line, capable of supplying water to be treated under pressure;
an in-line gas induction means capable of introducing oxygen-containing gas into the water;
a mixing chamber communicating with said water input line and capable of thoroughly mixing the gas with the water under pressure as a result of the action of centrifugal force due to the flow of the water in the chamber through a spiral core element, thereby producing a dispersion of the gas in the water so as to effect oxidation of contaminants in the water;
filtration means capable of separating precipitated particulate contaminants from the water after mixing; and means for recovering the treated water.
10. A water treatment apparatus as claimed in claim 9, wherein said in-line gas induction means comprises a venturi.
11. A water treatment apparatus as claimed in claim 9, wherein the angle of deflection of said spiral core static mixer is within the range of 27 to 39 degrees.
12. A water treatment apparatus as claimed in claim 9, 10 or 11, wherein said pressure means is capable of applying pressure to the water and gas within the range of from 10 to 65 psi.
13. A water treatment apparatus as claimed in claim 9, 10 or 11 wherein the centrifugal force is produced by a pressure loss within the range of 6 to 18 psi during substantial flow.
14. A water treatment apparatus as claimed in claim 9, 10 or 11, wherein said filtration means is a catalytic filter bed.
15. A water treatment apparatus as claimed in claim 9, 10 or 11, wherein said apparatus further comprises means for applying a reverse flow of wash water through said filtration means.
16. A water treatment apparatus as claimed in claim 9, 10 or 11, wherein said apparatus further comprises automatic means for periodic reverse flow of wash water through said filtration means.
17. A water treatment method as claimed in claim 1, 2 or 3, wherein the centrigual force created by the flow through a spiral core static element whose angle of deflection is within the range of 27 to 89 degrees.
18. A water treatment method as claimed in 1, further comprising the step of applying a reverse flow of wash water through the filter when the treatment system is not in normal use to provide for a cleaning of said filter.
19. A water treatment method as claimed in claim 18, wherein the provision of said reverse flow is automatic and periodic.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000564330A CA1263769A (en) | 1988-04-15 | 1988-04-15 | Water treatment method and apparatus |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000564330A CA1263769A (en) | 1988-04-15 | 1988-04-15 | Water treatment method and apparatus |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1263769A true CA1263769A (en) | 1989-12-05 |
Family
ID=4137850
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000564330A Expired CA1263769A (en) | 1988-04-15 | 1988-04-15 | Water treatment method and apparatus |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1263769A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6953525B2 (en) | 2002-05-28 | 2005-10-11 | Ms Filter Inc. | Potable water treatment plant and method of maintaining same |
-
1988
- 1988-04-15 CA CA000564330A patent/CA1263769A/en not_active Expired
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US6953525B2 (en) | 2002-05-28 | 2005-10-11 | Ms Filter Inc. | Potable water treatment plant and method of maintaining same |
| US7258798B2 (en) | 2002-05-28 | 2007-08-21 | Ms Filter Inc. | Potable water treatment plant and method of maintaining same |
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