AU2005209603A1 - Nitrate removal in waste water systems - Google Patents
Nitrate removal in waste water systems Download PDFInfo
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- AU2005209603A1 AU2005209603A1 AU2005209603A AU2005209603A AU2005209603A1 AU 2005209603 A1 AU2005209603 A1 AU 2005209603A1 AU 2005209603 A AU2005209603 A AU 2005209603A AU 2005209603 A AU2005209603 A AU 2005209603A AU 2005209603 A1 AU2005209603 A1 AU 2005209603A1
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- containment area
- waste water
- denitrification
- nitrate
- denitrification system
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- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Description
08-SEP-2005 12:24 A J PARK 64 4 472 3358 P.05/19 0) -1-
AUSTRALIA
PATENTS ACT, 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT
ORIGINAL
Regulation 3.2 Name of Applicant: Actual Inventors: Address for service in Australia: Invention Title: INSTITUTE OF GEOLOGICAL NUCLEAR SCIENCES
LTD
CHRISTOPHER JOHN DAUGHNEY; STEWART GRAHAM CAMERON and ROBERT RICHARD REEVES A J PARK. Level 11.60 Marcus Clarke Street, Canberra ACT 2601, Australia Nitrate Removal In Waste Water Systems The following statement is a full description of this invention, including the best method of performing it known to us.
467874 IDJOC COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 Oe-SEP-2005 12:24 A J PRRK 08-EP-200 1224 5 ARK64 4 472 3358 P.06/19 Cl NITRATE REMOVAL IN WASTE WATER SYSTEMS YIELD OF ENVENTION 00 Tfhe invention relates to the denitrificatian of waste water and in particular to the denitrification of municipal effluent using carbon based material.
o BACKGROUND One of the components of waste water is nitrogen. Nitrates leaching into waterways can lead to the growth of undesirable algae and other aquatic plant life. Alternatively nitrogen leached as ammonia can be toxic to aquatic life. For environmental reasons the nitrogen content of waste water must be reduced as far as possible.
One example of an -existing system for reducing nitrogen levels in waste water is a recirculating sand filter with anaerobic filter and carbon source. In this system waste water is first passed through a septic tank and then into a recirculation tank. From the recirculation tank the waste water passes through a sand filter. After passing through the sand filter some waste water is fed back to the recirculation tank. Carbon from a carbon source is added to the remaining waste water which then passes into an anaerobic ffiter. The waste water from the anaerobic filter is then passed to subsurfae infiltration and optionally to surface discharge. These systems normally remove 40 to of influent nitrogen.
US patent 5,288,407 describes another denitrification system. The process of US 5,288,407 involves waster water receiving an initial treatment mn a setting basin (which may be a septic tank). Effluent waste water from the settling basin flows into an aerobic, free-draining nitriflcation field either by fixed-bed gravity or by pumping. The nitrification field consists of a graded media through which waste water enters at the top. After passing through the graded media and becoming nitrified, waste water is collected at the bottom of the nitrification field. This waste water flows by gravity to a flow splitting device that divides -the waste water flow two strams. One waste water 204672 DOC 2 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 B8-SEP-2005 12!24 A J PARK 64 4 472 3358 P.07/19 0 C'N flow stream is recirculated back to the nitrification field by pumping; the other waste jwater flow stream flows by gravity to the denitrification chamber which utilizes sulphur and limestone as denitrification media. After passing through the denitrification 00 o chamber, denitrified waste water is conveyed to a discharge system. This denitrification system relies on endogenous carbon for the denitrification process.
0 N SUMMARY OF INVENTION 0 C<1 i It is the object of the invention to provide an improved or alternative denitrification S 10 process or to at least provide a useful choice of denitrification processes.
In broad terms in one aspect the invention comprises a method of controlling a denitrifleation process comprising the steps of monitoring the nitrate concentration of waste water entering a containment area, the containment area containing a carbon source, monitoring the nitrate concentration of waste water exiting the containment area, monitoring the temperature within the containment area, and adjusting the flow rate of waste water entering the containment area based on the nitrate concentration of waste water entering and exiting the containment area and the temperature within the containment area so as to achieve a required nitrate removal efficiency.
Preferably the method of controlling the denitrification process further comprises using a computer to determine the nitrate removal efficiency.
Preferably the computer controls a valve to adjust the flow rate of waste water entering the containment area.
In broad terms in a further aspect the invention comprises a denitrification apparatus comprising a containment area with an impermeable boundary on at least the bottom and sides of the containment area, the containment area at least partially filled with a carbon source, an inflow pipe into the containment area, an outflow pipe from the containment area, the inflow pipe and outflow pipe arranged to provide gravity drainage to the containment area.
20467-2.DOC 3 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 08-SEP-2005 12:24 A J PARK 64 4 472 3358 P.08/19 0 0 SPreferably the containment area is below ground level.
00 0 Preferably the containment area is covered with a layer of geo-fabric.
Cn Preferably the dimensions of the containment area are determined by the waste water 0 \O volume, the waste water temperature, the atmospheric temperature and the sustainable 0 nitrate concentration in the waste water entering the containment area.
S 10 Preferably the containment area is an elongated trench.
Preferably the carbon source in the containment area comprises one or more of woodchips, sawdust, activated carbon, or other vegetable based materials.
BRIEF DESCRIPTION OF DRAWINGS The invention will be further described by way of example only and without intending to be limiting with reference to the following drawings, wherein: Figure 1 is an overview ofa denitrification trench and plumbing design; and Figure 2 is an overview of a real-time nitrate monitoring system.
DETAILED DESCRIPTION Figure 1 shows an overview of a denitrification trench and plumbing design. Waste water enters the denitrification containment area 1 through inflow line 2. After processing in the trench the waste water exits the containment area I through outflow line 3.
In the embodiments shown in Figures 1 and 2 inflow line 2 and outflow line 3 are pipes.
In the embodiment of denitrification trench shown in Figure 1 the waste water flows 2046722.DOC 4 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 Oe-SEP-2005 12:25 A J PARK 08-EP-00512:5 PJ PRK64 4 472 3356 P.09/19 CA into and out of the containment area via a gravity feed system so that waste water flows down into the containment area I and flow down out of the containment area 1. An advantage of using a gravity feed system for the containment area is that it is cost o0 efficient to construct as no pumps are required to remove waste water from the containment area. Pumping may be required into the bed depending on the height en difference between the upstream treatment plant (not shown) and the bed and the waste water flow rate required to be input through the bed. In alternative embodiments ether feed systems may be used to supply waste water to the containment area.
Containment area 1 includes an impermeable membrane liner 4 that prevents direct Nl seepage of waste water from the sides and bottom of the containment area into the soil and groundwater system surrounding the containment area. The containment area is tilled with carbon source S. The carbon source may be any suitable material but in preferred embodiments is one or more of; wood chips, sawdust activated carbon, or any other suitable vegetative based material. In one embodiment the carbon source is Radiata pine wood chips and sawdust. In the preferred embodiment the containment area is non-baffled. In this embodiment the residence time of the waste water within the containment area is determined by the hydraulic conductivity of the carbon source, the containment area dimensions and the waste water inflow rates. The carbon source must have appropriate hydraulic conductivity to maintain trench drainage and waste water residence time in the containment area. In alternative embodiments the waste water residence time may be controlled by other means.
Nitrate is removed from the waste water by anaerobic biological activity. The anaerobic biological activity is provided by natural microbes that become very active in environments rich in carbon, from the carbon source, and nitrate, from the waste water.
The anaerobic activity produces the following denitrification reaction: 2 0 NO; 5C0 2 +2N 2 +3H 2 0 The above reaction results in nitrate being converted into N 2 gas. The optimisation of nitrogen removal in the containment area requires maximising the nitrate component of nitrogen in the waste water at the treatment plant.
204672 ZDOC COMS ID No: SBMI-014761 10 Received by IP Australia: Time 10:26 Date 2005-09-08 08-SEP-2005 12-'25 A J PnRK 08-EP-200 1225 5 PRK64 4 472 3358 P.10/19 (N The optimumn volume of the containment area and the carbon source within the containment area is dependent on several factors including the expected maximum waste water volume per day, the maximum instantaneous waste water flow rate and the o0 long term sustainable waste water nitrate concentration discharged from the treatment plant. As a rule of thumb as the expected maximum waste water volume per day en increases so will the required containment area and carbon source volumes. As the NO0 maximum instantaneous waste water flow rate increases so will the required containment area and carbon source volumes. As the sustainable waste water nitrate ~fl concentration discharged -from the treatment plant decreases the required containment area, and carbon source volumes will increase.
In preferred embodiments, as shown in Figure 1, a geo-fabric 6 covers the carbon source within the containent area 1. The geo-fabric prevents potential erosion of the carbon source. The geo-fabric 6 may be covered with a layer of material, for example bark 7, to provide a visual aesthetic cover to the containment area In alternative embodiments the geo-fabric and covering material may be omitted. The geo-fabric is permeable to allow rainfall to infiltrate the containment area and nitrogen gas to escape the containent area. Typically the gee-fabric is synthetic.
The reaction rate for converting nitrate into nitrogen gas in the containment area is dependent on temperature and availability of carbon. The reaction rate decreases with decreasing temperature and/or a reduction in carbon availability. Temperature probe 8 is provided to monitor the temperature within the containment area. In alternative embodiments more than one temperature probe may be provided within the containiment area. It is preferred that if more than one temperature probe is provided within the containment rea the temperature probes are substantially evenly spaced within the containment area to provide the most accurate possible indication of temperature within this area. In the preferred embodiment the temperature probe is installed in a piezometer.
The concentration of nitrate in thie waste water entering the containment area 1 is monitored by upstream monitoring chamber 9 on the inflow line 2. The concentration 2046 72 2.DOC 6 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 09-SEP-2005 12:26 A J PARK 08-EP-005 12:6 F 3 PRK64 4 472 3358 P.11/is 0 of nitrate in the waste water exiting containment area 1 is monitored by downstream monitoring chamber 10 on the outflow line 3. A flow valve 11 is also provided on the CO inflow line 2 to control the flaw of waste water into the monitoring chamber 9 and 00 containment area 1.
Mc Figure 2 shows a real time monitoring system for the denitiffication treatment system of IDthe invention. The monitoring system includes a computing devie1 htrcie information from nitrate probes 13, 14 on the inflow and outflow lines 2 and 3 respectively and from temperature probe 8.
01 Ci Computing device 17 may be positioned close to the denitrification treatment system or may be remote from the denitiification treatment system, The computing device may be a computer, microprocessor, microcontroller or any suitable device, If the computing device is close to the denitrification system connections 18 and 19 between the nitrate probes, temperature probe, flow meter and the computing device may be wired.
Alternatively connections 18 and 19 may be wireless. It should be noted that while connection 18 between the nitrate probes, temperaue sensor and the computing device is shown as a single connection this represents a connection between each nitrate probe and the computing device and a connection between the temperature sensor and the computing device.
The upstream monitoring chamber 9 and the downstream monitoring chamber 10 house not only nitrate probes 13, 14 but also electronics to communicate readings fronm the nitrate probes to computing device 17. If the connections between the monitoring 2$ chambers and the computing device are wireless the electronics in tlhe monitoring chambers may include cellular telephones or radio telemetry. Electronics in the monitoring chambers may be arranged to respond to a query from the computing device or to send information representing probe readings to the computing device at preset time intervals (for example at one minute intervals), Alternatively the electronics could be arranged to send information representing probe reading to the computing device if the probe reading are outside preset limits. In yet other alternative embodiments a 204672_2.DOC 7 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 Oe-SEP-2005 12:26 A J PARK 08-EP-805 1226 J mv64 4 472 3358 P.12/19 0 combination of these arrangements or any other suitable probe information reporting amrngement may be used.
0o The temperature probe(s) 8 is/are also attached to electronics to communicate readings from the temperature probe(s) 8 to the computing device. The electronics may include en cellular telephones or radio telemetry if the computing device is wirelessly connected to the electronics. Electronics attached to the temperature probe(s) may be arranged to respond to a query from. the computing device or to send information representing probe readings to the computing device at preset time intervals. Alternatively the electronics could be arranged to send information representing probe reading to the computing Cldevice if the probe reading are outside preset limits. In yet other alternative embodiments a combination of these arrangements or any other suitable probe information reporting arrangement may be used.
Flow valve 11I is also attached to electronics that control the flow valve. The electronics may include cellular telephones or radio telemetry if the computing device is wirelessly connected to the electronics. The electronics are arranged to respond to a signal from computing device 17 via connection 19 and control the flow valve to control the flow rate of waste water into the containment area.
In use computing device 17 receives data from nitrate probes 13 and 14 and temperature probe(s) 8 corresponding to the nitrate rate of waste water flowing into the containment area, the nitrate rate of waste water flowing out of the containment area and the temperature within the containment area respectively. The computing device then calculates the clenitrification efficiency of the containment area for the current waste water flow rate, the waste water nitrate concentration and the containment area temperature. Nitrate removal efficiency is determined as the difference between the inflow and outflow nitrate concentrations as measured by nitrate probes 13 and 14. If the nitrate removal efficiency of the containment area is less than a predefined percentage (for example 99%) the computing device sends a signal to the flow meter to reduce the flow rate of waste water into (and out of) the containment area. The flow rate is reduced to an appropriate rate to maintain the nitrate -removal efficiency of the 204672 ,DOC 8 COMS ID No: SBMI-01 476110 Received by IP Australia: Time 10:26 Date 2005-09-08 08-SEP-2005 12:26 A J PARK 0B-EP-00512:6 Pj PRK64 4 472 3358 P.13/1S ci containment area above the predefined percentage. The new flow rate is based on a calculation that takes into account the containment area temperature and the waste water CO residence time inside the containment area. The denitrification system efficiency to o0 reduce total nitrogen concentration of the waste water requires pre-trench treatment maximising the conversion of nitrogen species into the oxidised form of nitrate before en entering the containment area.
For example the temperature in the containment area may fluctuate. As the containment area temperature fluctuates the reaction rate in the containment area also fluctuates leading to a fluctuation in the denitrification system efficiency. This fluctuation in ci temperature and efficiency is detected by the computing system which alters the flow rate into and out of the containment area to maintain minimum nitrate removal effic-iey.
Over time, with prolonged usage the availability of carbon in the containment area may decrease. This decrease in carbon availability leads to a decrease in denitrification efficiency that is independent of efficiency changes due to temperature fluctuations.
The change in denitrification efficiency is detected by the computing system Which adjusts the flow rates into and out of the containment area accordingly. The computing system may also provide an estimate of the carbon availahility in the containment area and provide an alert when the carbon availability needs to be increased.
The containment area and monitoring system provides for optimisation of the containment area size based on the estimated peak waste water loading rates. The system maximnises nitrate removal from the waste water by adjusting the inflow rates to maintain denitrification efficiency.
The term 'comprising' as used in this specification and claim means 'consisting at least in part of', that is to say when interpreting statements in this specification and claims which include that term, the features, prefaced by that term in each statement, all need to be present but other features can also be present.
204672 2.DOC 9 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 OB-SEP-2005 122 A J PARK 64 4 472 3358 P.14/19 0 0 ci i The foregoing describes the invention including preferred forms thereof. Alterations and modifications as will be obvious to those skilled in the art are intended to be 00 o incorporated in the scope hereof.
ON
O
2o4672.zoOC COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08
Claims (5)
- 08-SEP-2005 12:2? A J PARK 64 4 472 3358 P.15/19 0 0 cqK CLAIMS CC 1. A method of controlling a denitrification process comprising the steps of: o monitoring the nitrate concentration of waste water entering a containment area, the containment area containing a carbon source, nmonitoring the nitrate concentration of waste water exiting the containment area, monitoring the temperature within the containment area, and 0adjusting the flow rate of waste water entering the containment area based on the nitrate concentration of waste water entering and exiting the containment area and the temperature within the containment area so as to achieve a required nitrate removal C'A efficiency. 2. A method of controlling a denitrification process as claimed in claim 1 further comprising the step of using a computer to determine the nitrate removal efficiency. 3. A method of controlling a denitrification process as claimed in claim 2 wherein the computer controls a valve to adjust the flow rate of waste water entering the containment area. 4. A denitrification system comprising: a containment area with an impermeable boundary on at least the bottom and sides of the containment area, the containment area at least partially filled with a carbon source, an inflow pipe into the containment area, an outflow pipe from the containment area, the inflow pipe and outflow pipe arranged to provide gravity drainage to the containment area. A denitrification system as claimed in claim 4 wherein the containment area is below ground level. 204672_2.DOC 11 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08 08-SEP-2005 12:2? A J PARK 64 4 472 3358 P.16/19 0 0 6. A denitrification system as claimed in claim 4 or claim 5 wherein the containment area is covered with a layer of geo-tabric. C) 00 0 0 7. A denitrification system as claimed in any one of claims 4 to 6 wherein the dimensions of the containment area are determined by the waste water volume, the waste water temperature, the atmospheric temperature and the sustainable nitrate Sconcentration in the waste water entering the containment area. 0 C 8. A denitrification system as claimed in any one of claims 4 to 7 wherein the S 10 containment area is an elongated trench.
- 9. A denitrification system as claimed in any one of claims 4 to 8 wherein the carbon source in the containment area comprises one or more of woodchips, sawdust, activated carbon, or other vegetable based materials. A denitrification system as claimed in any one of claims 4 to 9 further comprising a computing system arranged to determine nitrate removal efficiency.
- 11. A denitrification system as claimed in claim 10 wherein the computing system is arranged to control the flow rate into the containment area.
- 12. A method of controlling a denitrification process, substantially as herein described with reference to the accompanying drawings.
- 13. A denitrification system, substantially as herein described with reference to the accompanying drawings. Dated this 8 th day of September 2005 INSTITUTE OF GEOLOGICAL NUCLEAR SCIENCES LTD By Their Attorneys: 204672 C5 12 204672J2.DOC 12 COMS ID No: SBMI-01476110 Received by IP Australia: Time 10:26 Date 2005-09-08
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| NZ535179A NZ535179A (en) | 2004-09-08 | 2004-09-08 | Nitrate removal in waste water systems |
| NZ535179 | 2004-09-08 |
Publications (3)
| Publication Number | Publication Date |
|---|---|
| AU2005209603A1 true AU2005209603A1 (en) | 2006-03-23 |
| AU2005209603B2 AU2005209603B2 (en) | 2011-01-27 |
| AU2005209603B8 AU2005209603B8 (en) | 2011-05-26 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2005209603A Ceased AU2005209603B8 (en) | 2004-09-08 | 2005-09-08 | Nitrate removal in waste water systems |
Country Status (2)
| Country | Link |
|---|---|
| AU (1) | AU2005209603B8 (en) |
| NZ (1) | NZ535179A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113044956A (en) * | 2020-10-16 | 2021-06-29 | 同济大学 | Stacked biological purification device for high-salinity wastewater and purification method thereof |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0509152A1 (en) * | 1991-04-17 | 1992-10-21 | Ecotechniek B.V. | Method and apparatus for processing manure |
| US5288407A (en) * | 1992-04-06 | 1994-02-22 | Henderson And Bodwell | Denitrification system |
| US6875355B2 (en) * | 2001-03-20 | 2005-04-05 | Mcgrath Michael B. | Denitrification system for nitrified wastewater or nitrified water |
-
2004
- 2004-09-08 NZ NZ535179A patent/NZ535179A/en not_active IP Right Cessation
-
2005
- 2005-09-08 AU AU2005209603A patent/AU2005209603B8/en not_active Ceased
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN113044956A (en) * | 2020-10-16 | 2021-06-29 | 同济大学 | Stacked biological purification device for high-salinity wastewater and purification method thereof |
| CN113044956B (en) * | 2020-10-16 | 2021-11-02 | 同济大学 | Stacked biological purification device for high-salinity wastewater and purification method thereof |
Also Published As
| Publication number | Publication date |
|---|---|
| AU2005209603B2 (en) | 2011-01-27 |
| AU2005209603B8 (en) | 2011-05-26 |
| NZ535179A (en) | 2005-12-23 |
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Free format text: THE NATURE OF THE AMENDMENT IS: ADD THE NAME OF THE CO-INVENTOR SCHIPPER, LOUIS ALBERT |
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| FGA | Letters patent sealed or granted (standard patent) | ||
| TH | Corrigenda |
Free format text: IN VOL 25, NO 4, PAGE(S) 452 UNDER THE HEADING APPLICATIONS ACCEPTED - NAME INDEX UNDER THE NAME INSTITUTE OF GEOLOGICAL & NUCLEAR SCIENCES LTD, APPLICATION NO. 2005209603, UNDER INID (54) CORRECT THE TITLE TO READ NITRATE REMOVAL IN WASTE WATER SYSTEMS |
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| MK14 | Patent ceased section 143(a) (annual fees not paid) or expired |