GB1580733A - Method of biological purification of sewage - Google Patents
Method of biological purification of sewage Download PDFInfo
- Publication number
- GB1580733A GB1580733A GB24380/77A GB2438077A GB1580733A GB 1580733 A GB1580733 A GB 1580733A GB 24380/77 A GB24380/77 A GB 24380/77A GB 2438077 A GB2438077 A GB 2438077A GB 1580733 A GB1580733 A GB 1580733A
- Authority
- GB
- United Kingdom
- Prior art keywords
- water
- filter
- backwashing
- plant
- oxygen
- 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
- 238000000034 method Methods 0.000 title claims description 17
- 238000000746 purification Methods 0.000 title claims description 7
- 239000010865 sewage Substances 0.000 title description 11
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 52
- 238000011001 backwashing Methods 0.000 claims description 20
- 230000001580 bacterial effect Effects 0.000 claims description 19
- 239000000463 material Substances 0.000 claims description 15
- 239000002351 wastewater Substances 0.000 claims description 14
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 12
- 229910052760 oxygen Inorganic materials 0.000 claims description 12
- 239000001301 oxygen Substances 0.000 claims description 12
- 239000008187 granular material Substances 0.000 claims description 8
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims description 6
- 229910052799 carbon Inorganic materials 0.000 claims description 6
- 238000004321 preservation Methods 0.000 claims description 6
- 238000011010 flushing procedure Methods 0.000 claims description 5
- 239000010802 sludge Substances 0.000 claims description 5
- 238000007254 oxidation reaction Methods 0.000 claims description 4
- 238000003756 stirring Methods 0.000 claims description 4
- 230000008030 elimination Effects 0.000 claims description 3
- 238000003379 elimination reaction Methods 0.000 claims description 3
- QJGQUHMNIGDVPM-UHFFFAOYSA-N nitrogen group Chemical group [N] QJGQUHMNIGDVPM-UHFFFAOYSA-N 0.000 claims description 3
- 230000003647 oxidation Effects 0.000 claims description 3
- 238000001914 filtration Methods 0.000 description 10
- 238000005406 washing Methods 0.000 description 7
- 238000004140 cleaning Methods 0.000 description 6
- 241000894006 Bacteria Species 0.000 description 5
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 4
- OKKJLVBELUTLKV-UHFFFAOYSA-N Methanol Chemical compound OC OKKJLVBELUTLKV-UHFFFAOYSA-N 0.000 description 3
- 239000002245 particle Substances 0.000 description 3
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N Silicium dioxide Chemical compound O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 2
- 239000007788 liquid Substances 0.000 description 2
- 229910052757 nitrogen Inorganic materials 0.000 description 2
- 238000009331 sowing Methods 0.000 description 2
- PAWQVTBBRAZDMG-UHFFFAOYSA-N 2-(3-bromo-2-fluorophenyl)acetic acid Chemical compound OC(=O)CC1=CC=CC(Br)=C1F PAWQVTBBRAZDMG-UHFFFAOYSA-N 0.000 description 1
- WQZGKKKJIJFFOK-GASJEMHNSA-N Glucose Natural products OC[C@H]1OC(O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-GASJEMHNSA-N 0.000 description 1
- 229910002651 NO3 Inorganic materials 0.000 description 1
- NHNBFGGVMKEFGY-UHFFFAOYSA-N Nitrate Chemical compound [O-][N+]([O-])=O NHNBFGGVMKEFGY-UHFFFAOYSA-N 0.000 description 1
- 229910000831 Steel Inorganic materials 0.000 description 1
- 229930006000 Sucrose Natural products 0.000 description 1
- CZMRCDWAGMRECN-UGDNZRGBSA-N Sucrose Chemical compound O[C@H]1[C@H](O)[C@@H](CO)O[C@@]1(CO)O[C@@H]1[C@H](O)[C@@H](O)[C@H](O)[C@@H](CO)O1 CZMRCDWAGMRECN-UGDNZRGBSA-N 0.000 description 1
- 238000009825 accumulation Methods 0.000 description 1
- WQZGKKKJIJFFOK-VFUOTHLCSA-N beta-D-glucose Chemical compound OC[C@H]1O[C@@H](O)[C@H](O)[C@@H](O)[C@@H]1O WQZGKKKJIJFFOK-VFUOTHLCSA-N 0.000 description 1
- 239000004927 clay Substances 0.000 description 1
- 235000013681 dietary sucrose Nutrition 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000011049 filling Methods 0.000 description 1
- 239000008103 glucose Substances 0.000 description 1
- 238000001033 granulometry Methods 0.000 description 1
- 238000002347 injection Methods 0.000 description 1
- 239000007924 injection Substances 0.000 description 1
- 235000013379 molasses Nutrition 0.000 description 1
- 150000002823 nitrates Chemical class 0.000 description 1
- 230000036284 oxygen consumption Effects 0.000 description 1
- 238000006213 oxygenation reaction Methods 0.000 description 1
- 210000002966 serum Anatomy 0.000 description 1
- 239000000377 silicon dioxide Substances 0.000 description 1
- 239000007787 solid Substances 0.000 description 1
- 239000010959 steel Substances 0.000 description 1
- 229960004793 sucrose Drugs 0.000 description 1
- 239000000725 suspension Substances 0.000 description 1
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
- C02F3/10—Packings; Fillings; Grids
-
- 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
- C02F3/06—Aerobic processes using submerged filters
-
- 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
- C02F3/28—Anaerobic digestion processes
- C02F3/2806—Anaerobic processes using solid supports for microorganisms
-
- 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
- C02F3/30—Aerobic and anaerobic processes
- C02F3/302—Nitrification and denitrification treatment
-
- 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)
- Microbiology (AREA)
- Biodiversity & Conservation Biology (AREA)
- Hydrology & Water Resources (AREA)
- Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Water Supply & Treatment (AREA)
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Biological Treatment Of Waste Water (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
(54) IMPROVED METHOD OF BIOLOGICAL PURIFICATION OF SEWAGE
(71) We, DEGREMONT, a body corporate, organized under the laws of the
French Republic, 183- Avenue du 18 Juin 1940, Rueil-Malmaison (France) do hereby declare the invention, for which we pray that a patent may be granted to us and the method by which it is to be performed, to be particularly described in and by the following statement.
The invention described in the Patent No.
1.399.515 makes use of a biological filter filled with a bed of filtration materials such as terra-cotta, or fire-clay, having a low granulometry, of the order of 0.5 to 4 mm, and preferably 2 mm, the filter surface comprising on the one hand limited areas permitting the fixation and preservation of the bacterial film even under intense and repeated washing condtions, and on the other hand a smooth appearence to permit the removal by washing of any bacterial culture on this smooth surface area.
The filter disclosed in the Head Patent is utilized in aero = biosis in a biological sewage purification plant; the incoming sewage fed to the filter is pre-aerated by means of a dome or porous tube having a high diffusion efficiency in order to increase the sewage oxygen concentration by approaching saturation as much as possible. By percolating on the filtration material this overoxygenated water is capable of developing on the one hand strict aerobic bacterial strains and optional aerobic bacterial strains thus the sewage purification is extremely pronounced with a relatively low oxygen consumption. A double nitrification and denitrification action is thus exerted on the filter.
Now it was discovered that a filter of this type, likely to operate under anaerobiosis conditions, is suitable for denitrifying sewage previously nitrified by over-oxidation.
It is known that denitrification is the biological reduction of nitrates produced during the oxidation of organic ammonium nitrate during the biological purification treatment in the presence of oxygen.
This denitrification affording a pronounced removal of nitrogen by releasing gaseous nitrogen takes place in the absence of oxygen; additional carbon is frequently necessary for obtaining a proper growth of the bacteria and also total anaerobiosis conditions.
It is known in the biological denitrification of sewage to utilize so-called biological, immersed, anaerobic filters comprising a filling consisting either of porous or cavernous materials of relatively large particle size (2 to 8 cm), or of smooth silica grains (0.5 to 2 mm). Due to their particular structure, these filters are prone to become rapidly clogged and therefore frequent cleaning operations are required. Filters filled with materials of relatively small particle size can be backflushed. This cleaning method is objectionable in that it causes the bacterial mass to be carried away, so that re-sowing is necessary.
Therefore, a reduced efficiency is observed inevitably after each cleaning operation.
According to the present invention there is provided a method of purifying waste water comprising passing the water through an immersed biological filter comprising a bed of granular material, the granules each having a surface area comprising limited zones permitting the fixation and preservation of a bacterial film which withstands strong and repeated backwashing or flushing stream condtions and a main portion having a smooth appearance permitting the easy removal by backwashing of any bacterial cul- ture carried by this smooth surface portion, and periodically backwashing the filter, the filter being kept in a state of anaerobiosis during said passage and backwashing, in order to allow elimination of nitrogenous pollution of the waste water. The waste water may be sewage.
The waste water supplied to the biological filter, which should be de-oxygenated before attaining the filtration material, may be directed to the filter via a conduit immersed under the liquid level kept at its minimum value.
The denitrifying bacteria growing on the filtration material are fixed more particularly in the hollow areas of this material. The film likely to develop on the smooth areas is torn off by the backflushing operation carried out by means of the deoxygenated water.
The development or growth of denitrifying heterotrophic bacteria may be obtained in the known fashion by introducing assimilable carbon into the water fed to the biological filter, this assimilable carbon being derived for example from methanol, glucose, saccharose or carbonated sub-products such as molasses, cheese-making serum, and the like.
The filter is cleaned without impairing its twofold function of physically retaining the solid particles in suspension and biologically fixing a purifying bacterial mass, by utilizing a backflushing water injection system operating in counter-current relationship to the normal flow produced through the filter bed.
The purpose of this cleaning operation is to stir strongly the grains and through the friction produced between adjacent grains, to tear off the bacterial film possibly formed on the smooth portions of the material, the bacterial sowing fixation areas, located in cavities in comparison with said smooth portions, remaining of course covered with denitrifying bacteria.
The washing step having become necessary on account of the slow accumulation of inert or living materials in the filtration mass is essential for preserving a normal homogenous flow of water to be denitrified through this filtration mass without causing excessive pressure losses.
This washing step is carried out by using previously deoxygenated water in order to keep the filter in the desired anaerobiosis conditions.
The single Figure of the attached drawing illustrates diagrammatically by way of example a biological denitrification filter according to this invention.
This biological filter comprises a cylindrical tank 1 of steel or plastic material, or a parallelipipedic concrete tank, provided with a double horizontal bottom 2; the top wall of this double bottom 2 is perforated to permit the flow of liquid therethrough and consists of a perforated plate or a plate provided with small nozzles.
Above this wall 2 the tank is filled with a mass of material of the kind disclosed in the foregoing.
Air and wash water are supplied via conduits 4 and 5, respectively, into the space formed between the two walls of the double-bottomed tank.
The air supply conduit 4 is adapted to be closed by means of a gate valve 17 when the filter is in anaerobiosis conditions.
The treated water outlet conduit 6 is stirrup-shaped in order to keep the water level above the filtration mass at a minimum height 7.
The level of the water layer in the tank may vary between a minimum 7 and a maximum 12, as shown in the drawing. The uppermost level 12 is controlled by means of an overflow device 11. Any water discharged through this device 11 is recycled in the plant as wash water for the phases preceding the denitrification, such as activated sludge or bacterial bed.
The water to be purified biologically is fed by a pump 13 via conduit 14 to the tank and flows downwardly through the filter mass 3, the perforated wall 2 and eventually the outlet 6.
The sewage fed by pump 13 as well as any wash water are derived from an auxiliary tank 19 in which water from preceding treatment steps (and fed via a conduit 20) is de-oxygenated. This tank is closed and equipped with slow-rotating stirring means, the quantity of dissolved oxygen being thus reduced to a value approximating zero.
Assimilable carbon is advantageously supplied via a conduit 21 to this water tank 19.
Reverting to the main filtration tank 1, the backflushing current is obtained by opening a valve 18 inserted in a conduit also connected to the auxiliary tank 19.
Now even repeated backflushings with water alone may prove insufficient for definitely cleaning the grain surface; therefore, an intense washing step carried out with air and water shall be performed periodically, but this will involve only a short-time reduction in the filter activity, since the denitrifying bacteria are optional anaerobic strains (in this case valve 17 is open).
When a plurality of parallel-connected filters are provided in a same plant, after this intense washing step the device may be supplied under normal filtering conditions with water flowing under closed-circuit conditions through the de-oxygenation tank 19 until the desired denitrification efficiency is restored.
The time required for performing a complete filtration cycle between two normal washing steps may vary as a function of the content of suspended matter in the water and its nitrate, contents, from 6 to 120 hours, and the number of normal cycles that can be contemplated between two exceptional airand-water cleaning operations may also vary from 3 to 12.
The filter operating under the abovedefined anaerobiosis conditions may advantageously be inserted in various sewage purification plants in which a nitrificationdenitrification treatment is to take place, whether the plant is of the activated sludge type or of the type comprising one or a plurality of immersed biological filters operating in aerobiosis, the high oxidation level required therefore being obtained by using either oxygen or oxygen-enriched air, the denitrification being performed on the filter according to this invention after de-oxygenating the water derived from the nitrification.
WHAT WE CLAIM IS:
1. A method of purifying waste water comprising passing the water through an immersed biological filter comprising a bed of granular material, the granules each having a surface area comprising limited zones permitting the fixation and preservation of a bacterial film which withstands strong and repeated backwashing or flushing stream conditions and a main portion having a smooth appearance permitting the easy removal by backwashing of any bacterial culture carried by this smooth surface portion, and periodically backwashing the filter, the filter being kept in a state of anaerobiosis during said passage and backwashing, in order to allow elimination of nitrogenous pollution of the waste water.
2. A method according to claim 1, in which the water fed to the filter and the backwashing water are deoxygenated before being fed to the filter.
3. A method according to claim 2 in which the water is deoxygenated in a closed tank provided with stirring means and means for supplying assimilable carbon thereto.
4. A method according to any preceding claim, in which the water is fed to the filter through a conduit opening at a point below the lowest level of water covering the filter material.
5. A method according to any preceding clai!--. in which the filter is washed at intervals with oxygen-containing water.
6. Plant for purifying waste water which comprises means for treating the water aerobically to nitrify the water and means for passing the aerobically treated water through an immersed biological filter, the filter comprising a bed of granual material, the granules each having a surface area comprising limited zones permitting the fixation and preservation of a bacterial film which withstands strong and repeated backwashing or flushing stream conditions and a main portion having a smooth appearance permitting the easy removal by backwashing of any bacterial culture carried by this smooth surface portion means being provided for periodically backwashing the filter and means being provided to remove oxygen from the water before the water enters the filter.
7. Plant according to claim 6, in which the means for treating the water aerobically comprises activated sludge.
8. Plant according to claim 6, in which the means for treating the water aerobically comprises an immersed biological filter.
9. A method of purifying waste water, substantially as hereinbefore described with reference to the accompanying drawings.
10. Plant for purifying waste water, substantially as hereinbefore described with reference to the accompanying drawings.
**WARNING** end of DESC field may overlap start of CLMS **.
Claims (10)
1. A method of purifying waste water comprising passing the water through an immersed biological filter comprising a bed of granular material, the granules each having a surface area comprising limited zones permitting the fixation and preservation of a bacterial film which withstands strong and repeated backwashing or flushing stream conditions and a main portion having a smooth appearance permitting the easy removal by backwashing of any bacterial culture carried by this smooth surface portion, and periodically backwashing the filter, the filter being kept in a state of anaerobiosis during said passage and backwashing, in order to allow elimination of nitrogenous pollution of the waste water.
2. A method according to claim 1, in which the water fed to the filter and the backwashing water are deoxygenated before being fed to the filter.
3. A method according to claim 2 in which the water is deoxygenated in a closed tank provided with stirring means and means for supplying assimilable carbon thereto.
4. A method according to any preceding claim, in which the water is fed to the filter through a conduit opening at a point below the lowest level of water covering the filter material.
5. A method according to any preceding clai!--. in which the filter is washed at intervals with oxygen-containing water.
6. Plant for purifying waste water which comprises means for treating the water aerobically to nitrify the water and means for passing the aerobically treated water through an immersed biological filter, the filter comprising a bed of granual material, the granules each having a surface area comprising limited zones permitting the fixation and preservation of a bacterial film which withstands strong and repeated backwashing or flushing stream conditions and a main portion having a smooth appearance permitting the easy removal by backwashing of any bacterial culture carried by this smooth surface portion means being provided for periodically backwashing the filter and means being provided to remove oxygen from the water before the water enters the filter.
7. Plant according to claim 6, in which the means for treating the water aerobically comprises activated sludge.
8. Plant according to claim 6, in which the means for treating the water aerobically comprises an immersed biological filter.
9. A method of purifying waste water, substantially as hereinbefore described with reference to the accompanying drawings.
10. Plant for purifying waste water, substantially as hereinbefore described with reference to the accompanying drawings.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB24380/77A GB1580733A (en) | 1977-06-10 | 1977-06-10 | Method of biological purification of sewage |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB24380/77A GB1580733A (en) | 1977-06-10 | 1977-06-10 | Method of biological purification of sewage |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| GB1580733A true GB1580733A (en) | 1980-12-03 |
Family
ID=10210835
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| GB24380/77A Expired GB1580733A (en) | 1977-06-10 | 1977-06-10 | Method of biological purification of sewage |
Country Status (1)
| Country | Link |
|---|---|
| GB (1) | GB1580733A (en) |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2604990A1 (en) * | 1986-10-01 | 1988-04-15 | Omnium Traitement Valorisa | METHOD FOR THE BIOLOGICAL PURIFICATION OF WASTEWATER ON BED OF GRANULAR MATERIAL |
| EP0526328A1 (en) * | 1991-08-02 | 1993-02-03 | OTV (OMNIUM de TRAITEMENTS et de VALORISATION) | Process for removal of organic nutrients containing carbon, nitrogen and phosphorus |
| US5605629A (en) * | 1992-08-03 | 1997-02-25 | Rogalla; Frank A. | Method for the removal of nutrients containing carbon, nitrogen and phosphorus |
| CN109448881A (en) * | 2018-12-05 | 2019-03-08 | 天津大学 | The devices and methods therefor of multistep Combined Treatment radioactive iodine pollution water |
-
1977
- 1977-06-10 GB GB24380/77A patent/GB1580733A/en not_active Expired
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2604990A1 (en) * | 1986-10-01 | 1988-04-15 | Omnium Traitement Valorisa | METHOD FOR THE BIOLOGICAL PURIFICATION OF WASTEWATER ON BED OF GRANULAR MATERIAL |
| EP0265303A1 (en) * | 1986-10-01 | 1988-04-27 | OTV (OMNIUM de TRAITEMENTS et de VALORISATION) | Process for biological waste water purification in a granular bed |
| EP0526328A1 (en) * | 1991-08-02 | 1993-02-03 | OTV (OMNIUM de TRAITEMENTS et de VALORISATION) | Process for removal of organic nutrients containing carbon, nitrogen and phosphorus |
| FR2679897A1 (en) * | 1991-08-02 | 1993-02-05 | Omnium Traitement Valorisa | PROCESS FOR THE BIOLOGICAL REMOVAL OF CARBON, NITROGEN AND PHOSPHORUS NUTRIENTS IN WASTEWATER. |
| US5605629A (en) * | 1992-08-03 | 1997-02-25 | Rogalla; Frank A. | Method for the removal of nutrients containing carbon, nitrogen and phosphorus |
| CN109448881A (en) * | 2018-12-05 | 2019-03-08 | 天津大学 | The devices and methods therefor of multistep Combined Treatment radioactive iodine pollution water |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PS | Patent sealed [section 19, patents act 1949] |