EP0946431A1 - Assainissement de l'eau souterraine a l'aide de diffuseurs microporeux - Google Patents

Assainissement de l'eau souterraine a l'aide de diffuseurs microporeux

Info

Publication number
EP0946431A1
EP0946431A1 EP97913956A EP97913956A EP0946431A1 EP 0946431 A1 EP0946431 A1 EP 0946431A1 EP 97913956 A EP97913956 A EP 97913956A EP 97913956 A EP97913956 A EP 97913956A EP 0946431 A1 EP0946431 A1 EP 0946431A1
Authority
EP
European Patent Office
Prior art keywords
gas
bubbles
bubble
aquifer
water
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.)
Ceased
Application number
EP97913956A
Other languages
German (de)
English (en)
Inventor
William B. Kerfoot
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
K-V Associates Inc
Original Assignee
K-V Associates Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from PCT/US1996/018464 external-priority patent/WO1997039984A1/fr
Priority claimed from US08/756,273 external-priority patent/US5855775A/en
Priority claimed from US08/921,763 external-priority patent/US6312605B1/en
Application filed by K-V Associates Inc filed Critical K-V Associates Inc
Publication of EP0946431A1 publication Critical patent/EP0946431A1/fr
Ceased legal-status Critical Current

Links

Classifications

    • 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

Definitions

  • the present invention relates to sparging apparatus, systems and methods of in-situ groundwater remediation for removal of contamination including dissolved chlorinated hydrocarbons and dissolved hydrocarbon petroleum products.
  • the present invention is directed to the use in injection wells of microfine bubble generators, matched to substrates of selected aquifer regions, for injection and distribution of said microfine bubbles containing oxidizing gas through said aquifer.
  • the present invention relates to selectively encapsulating multiple gases including oxygen and ozone in said microfine bubbles to form "gas-gas" bubbles which, in the presence of co-reactant substrate material acting as a catalyst, are effective to encourage biodegradation of leachate plumes which contain biodegradable organics, or Criegee decomposition of leachate plumes containing dissolved chlorinated hydrocarbons.
  • U.S. Patent No. 4,614,596 to Wyness discloses a method for dissolving a gas in an aqueous stream which comprises diffusing a gas in an aqueous stream to produce small gas bubbles which are rotated to provide a long flow distance over which the bubbles have increased contact time.
  • the figures show that the bubbles are dispersed within and outward from a vessel, or well casing, by maximizing the dispersal of bubbles from a well casing and maximizing contact with the bubbles.
  • Wyness also teaches an enhanced dissolved aqueous reaction.
  • the prior art fails to show matching of micron sized bubble formation with substrate material of a selected aquifer or to show the beneficial effect of uniform distribution of sized bubbles through such a formation by means of a pulsed wave form without fracturing said substrate.
  • the present invention accomplishes this by injecting micron size bubbles containing an ozone oxidizing agent by means of microporous diffusors into aquifer regions, in combination with substrate materials acting as a catalyst to encourage biodegradation of leachate plumes which contain biodegradable organics by means of a gas/gas/water reaction which overcomes at least some of the disadvantages of prior art.
  • the present invention relates to injection of oxidizing gas in the form of microfine bubbles into aquifer regions by means of a sparging apparatus, systems and methods which includes one or more injection wells to encourage in-situ remediation of subsurface leachate plumes by means of a gas-gas-water reaction.
  • the present invention is directed to sparging apparatus, systems and methods of in-situ groundwater remediation in combination with co-reactant substrate materials acting as a catalyst to encourage biodegradation of leachate plumes for removal of dissolved chlorinated hydrocarbons and dissolved hydrocarbon petroleum products. Remediation of saturated soils may also be obtained by employment of the present invention.
  • the sparging system of the present invention encourages biodegradation of leachate plumes which contain biodegradable organics or Criegee decomposition of leachate plumes containing dissolved chlorinated hydrocarbons.
  • said apparatus includes microporous bubble generators adapted to generate micron sized gas-gas bubbles for injection into aquifer regions by means of one or more vertically arranged injection wells having a bubble chamber configured to control the size of said bubbles.
  • the present invention is directed to sparging apparatuses for employing microporous diffusers for injecting micro-fine bubbles containing encapsulated gas bubbles into aquifer regions to encourage biodegradation of leachate plumes which contain biodegradable organics, or Criegee decomposition of leachate plumes containing dissolved chlorinated hydrocarbons.
  • the sparging apparatuses of the present invention employing microporous diffusers for injecting an encapsulated multi-gas oxidizing agent, are particularly useful in that the apparatuses promote extremely efficient removal of poorly biodegradable organics, particularly dissolved chlorinated solvents, without vacuum extraction of undesirable by-products of remediation and wherein remediation occurs by employing encapsulated multi-gas oxidizing agents for destroying organic and hydrocarbon material in place without release of contaminating vapors.
  • the groundwater and soil remediation system comprises oxidizing gas encapsulated in microbubbles generated from microporous diffusers matched to soil porosity.
  • a unique bubble size range is matched to underground formation porosity and achieves dual properties of fluid-like transmission and rapid extraction of selected volatile gases, said size being selected so as to not to be so small as to lose vertical mobility.
  • a prior site evaluation test procedure is devised to test effectiveness of fluid transmission at the site to be remediated.
  • the advantage of controlled selection of small bubble size is the promotion of rapid extraction of selected volatile organic compounds, such as PCE, TCE, or DCE by incorporating the exceptionally high surface to gas volume ratio.
  • the dual capacity of the small production and rise time is matched to the short lifetime of an oxidative gas, such as ozone, to allow rapid dispersion into water saturated geological formations, and extraction and rapid decomposition of the volatile organic material.
  • an oxidative gas such as ozone
  • the unique apparatus of the present invention provides for extraction efficiency with resulting economy of operation by maximizing contact with oxidant by selective rapid extraction providing for optimum fluidity to permit bubbles to move like a fluid through media which can be monitored.
  • microporous bubble generators provides a more even distribution of air into a saturated formation than the use of pressurized wells.
  • a microfine sparge system installed to remediate contaminated groundwater is made more cost-effective by sparging different parts of the plume area at sequenced times.
  • Bubble generator locations and sequence control Through the proper placement of bubble generator locations and sequence control, any possible off-site migration of floating product is eliminated.
  • water mounding is used to advantage in preventing any off-site escape of contaminant. The mounding is used to herd floating product toward extraction sites.
  • the concept of microfine sparge system manipulation is predicated upon a thorough knowledge of the features of the groundwater or saturated zones on a site selected for remediation.
  • Balancing the volume of air to the microfine system sparge loci enables control of sparging efficiency and balancing of any downgradient movement of a contaminated plume while remediation is accomplished.
  • Critical to microfine sparge system design and accomplishment of any of the above points is the initial performance of a "sparge point test" for the purpose of evaluating the characteristics of the site for matching purposes.
  • the invention employs the well recognized Criegee mechanism which describes the gaseous reaction of ozone with the incoming PCE, TCE, DCE, and vinyl chloride into microbubbles produced by bubble generators with the resultant products then hydrolysed, i.e., reacted with water to decompose into HCl and CO 2 . It is this physical/chemical reaction which produces the rapid removal rate employed by the present invention (see reference Maston S 1986, “Mechanisms and Kinetics of Ozone Hydroxal Radical Reactions with Model Alafadic and Olanfadic Compounds", Ph.D. Thesis, Harvard University, Cambridge, MA).
  • the contaminated groundwater is injected with an air/ozone mixture wherein microfine air bubbles strip the solvents from the groundwater and the encapsulated ozone acts as an oxidizing agent to break down the contaminants into carbon dioxide, very dilute HCl and water.
  • This process is also known as the C-SpargerTM system, which is directed to low-cost removal of dissolved chlorinated hydrocarbon solvents such as percolate from contaminated soil and groundwater aquifers.
  • the C-SpargerTM system employs microporous diffusers, hereinafter Spargepoints® for producing micro-fine bubbles containing an oxidizing agent that decomposes chlorinated hydrocarbons into harmless byproducts.
  • the C-SpargerTM system comprise pumps for pumping a multi-gas oxidizing mixture through a) the Spargepoint diffusors into groundwater in a soil formation; b) a bubble production chamber to generate bubbles of differing size, c) a timer to delay pumping until large bubbles have segregated from small bubbles by rise time, wherein fine bubbles and liquid are forced into the formation.
  • the pump intermittently agitates the water in the well in which the C-Sparger is installed.
  • a unique bubble size range is matched to underground formation porosity and achieves dual properties of fluid-like transmission and rapid extraction of selected volatile gases, said size being so selected so as to not to be so small as to lose vertical mobility.
  • a prior site evaluation test procedure is devised to test effectiveness of fluid transmission at the site to be remediated.
  • the dual capacity of the small bubble production pulsed injection and rise time is matched to the short lifetime of an oxidative gas, such as ozone to allow rapid dispersion into predominantly water-saturated geological formations, and extraction and rapid decomposition of the volatile organic material.
  • the unique apparatus of the present invention provides for extraction efficiency with resulting economy of operation by maximizing contact with oxidant by selective rapid extraction providing for optimum fluidity to permit bubbles to move like a fluid through media which can be monitored.
  • the micro-fine bubbles produced by the Spargepoint diffusors contain oxygen and ozone which oxidize the chlorinated hydrocarbons to harmless gases and weak acids. High initial concentrations of these dissolved organics have been, under some specific circumstances, reduced to levels of 1 ppb or less in periods of a few weeks. None of the models to date are designed for explosive environments.
  • microporous diff ⁇ sor points provides a more even distribution of air into a saturated formation than the use of pressurized wells.
  • a sparge system installed to remediate contaminated groundwater is made more cost-effective by sparging different parts of the plume area at sequenced times. Through the proper placement of sparge locations and sequence control, any possible off-site migration of floating product is eliminated. With closely spaced sparge points, water mounding is used to advantage in preventing any off-site escape of contaminant. The mounding is used to herd floating product toward extraction sites.
  • the present invention employs a plurality of configurations consisting of Series 3500 and
  • the 3600 Series is larger and has more capacity. Specifically, the 3600 Series has a better compressor rated for continuous use, a larger ozone generator, a second spargepoint below the first in each well, and larger diameter gas tubing. Both model series have control units that can support: one (Models 3501 & 3601), two (Models 3502 & 3602) and three separate wells (Models 3503 & 3603). The differences between the one, two, and three well models are in the numbers of relays, internal piping, external ports and programming of the timer/controller.
  • Normal operation for C-SpargerTM systems includes carrying out, in series for each well, the following functions on a timed basis: pumping air & ozone through Spargepoint diffusers into the soil formation, pumping aerated/ozonated water in the well into the soils, and recovering treated water above. Treatment is followed by a programmable period of no external treatment and multiple wells are sequenced in turn. Agitation with pumped water disturbs the usually inverted cone-shaped path of bubbles through the soils and disperses them much more widely This increases contact and greatly improves efficiency and speed of remediation. Vapor capture is not normally necessary.
  • Series 3500 and 3600 systems include a control Module (Box), one to three well assemblies depending on specific model selected, a submersible pump power-gas line for each well, and a flow meter (to check spargepoint flow rates).
  • Model Series 3500 & 3600 Control Modules have been successfully deployed outdoors in benign and moderate environments for prolonged periods of time. The Control Module must be firmly mounted vertically on 4 x 4 posts or a building wall near the wells.
  • Microfine bubbles accelerate the transfer rate of PCE from aqueous to gaseous state
  • the bubble rise transfers the PCE to the vadose zone
  • the ten-fold difference in surface-to-volume ratio of Spargepoint diffusor microbubbles compared to bubbles from well screens results in a four-fold improvement in transfer rates.
  • a microprocessor system shuttles an oxidizing gas through the vadose zone to chemically degrade the transported PCE. Elimination rate of PCE Relative to Ozone Content"
  • the object and purpose of the present invention is to provide microporous diffusors for in-situ removal of contaminants from soil and associated subsurface ground water aquifer, without requiring applying a vacuum for extraction biodegradation by-products
  • Another object is to provide multi-gas systems to be used in combination with the microporous diffusors to promote an efficient removal of poorly biodegradable organics, particularly dissolved chlorinated solvents, without vacuum extraction.
  • a further object is to provide that remediation occurs by destroying organic and hydrocarbon material in place without release of contaminating vapors to the atmosphere.
  • a further object is to provide for economical and efficient remediation of contaminated groundwater by providing a calculated plan of sparging different parts of a plume area at sequenced times.
  • Another object is to provide microfine sparge system manipulation predicated on performance of a site evaluation test
  • a further object is to provide that remediation occurs by destroying organic and hydrocarbon material in place without release of contaminating vapors to the atmosphere
  • Another object is to provide a microfine sparge system providing for optimum fluidity to permit bubbles to move like a fluid through media.
  • FIG. 1 is a cross sectional schematic illustration of a soil formation showing the system of the present invention.
  • Figure 2 shows an enlarged piping schematic of the present invention of Figure 1 showing the unique fine bubble production chamber
  • Figure 3. is an electrical schematic for a 3 well system of the present invention of Figure 1
  • Figure 4. shows an internal layout of the Control Module box for a three well system of the present invention of Figure 1,
  • Figure 5A shows the geometry of the bottom panel on the Control Module identifying the external connections and ports for three well units of the invention of Figure 1;
  • Figure 5B is the left side view of Figure 5 A;.
  • Figure 6. is a schematic illustration of a soil formation showing the method for the present invention.
  • Figure 7. is a graph illustrating pore size compared with air bubble size.
  • Figure 8. is an illustration of radiation of bubbles from standard .010 (10 Slot) well screen compared to microporous diffusor.
  • Figure 9. is an illustration of permeability of glass beads compared with permeability of soil fractions.
  • Figure 10 is a plan view of three different types of bubble generators and installations of the present invention.
  • Figure 11. is an illustration of flow chart for a sparge test according to the present invention
  • Figure 12. is a schematic illustration of apparatus used in in-situ sparge test according to the present invention.
  • Figure 13 is a graph illustrating pressure/flow relationship observed in different formations.
  • Figure 14. is a graph illustrating influence of depth and pressure on radius of bubble zone.
  • Figure 15. is a graphical illustration of PCE removal rate as function of bubble size.
  • Figure 16. is an illustration of flushmount wellhead assembly in roadbox according to the present invention.
  • Figure 17. is a schematic illustration of the use of zone control in the present invention.
  • Figure 18. is a schematic illustration of depiction of bubble zone and mounding.
  • Figure 19 is a schematic illustration of bubble zone and mounded area above the active aeration according to the present invention.
  • Figure 20 is an illustration of sequential rise in water table from bubbling and concentric zones permitting containment of any floating contaminant - side view.
  • Figure 21 is schematic illustration of sequential rise in water table from bubbling and concentric zones permitting containment of any floating contaminant - top view
  • Figure 22A is a schematic illustration of contrast between aeration gaps with non-overlapping and thirty percent (30%) overlapping sparged zones.
  • Figure 22B is a cross sectional schematic illustration of bubble generator (Spargepoint®) apparatus well pumping above.
  • Figure 23 is a plan view of a "C-SpargerTM system.
  • Figure 24 is a cross sectional schematic illustration of an inwell assembly.
  • Figure 25 is a top view of a ten point diffusor installation.
  • Figure 26 is a cross sectional schematic illustration of deep slant-well installations to create selective bubble fence using equal spacing often diffusors.
  • Figure 27 is a graphical illustration of PCE concentrations.
  • Figure 28 shows movement of microbubbles through saturated pores as diameter of bubble increases, showing coalescing
  • Figure 29 is a graphical illustration of rapid reaction of gas/gas mixture when passing through moistened sand.
  • Figure 30 is a schematic diagram of gas/gas/water reactions contrasted with previous known ozone reactions.
  • Figure 31 is a diagram of ozone reactions illustrating Criegee mechanism for gas/gas/water reaction with tetrachloroethene (PCE).
  • Figure 32. shows a microbubble generator column chamber and process.
  • FIG. 33 shows pressure waves created by C-SpargerTM unit during operation.
  • Figure 34 is a graphical illustration of frequency of microbubbles entering monitoring well screen at 15 ft. distance compared to pressure wave from C-SpargerTM unit during water pumpage (pump), lower bubble generator (Spargepoint®) operation (lover SP) and in-well bubble generator (Spargepoint®) operation (in-well SP).
  • Figure 35. shows induced recirculation from bubble distribution.
  • Figure 36 is a graphical illustration of expanding zone of influence when air and then air/ozone mixtures are injected with C-SpargerTM recirculation system.
  • Figure 37. shows remote C-SpargerTM process interrogator and controller.
  • Figure 38. shows a pass-through threaded microporous spargepoint assembly.
  • FIG. 1 there is shown a microfine sparge apparatus, system and method employing oxidizing gas encapsulated in microbubbles generated from microporous diffusors matched to soil porosity in a wave form employing a co-reactant in the form of substrate material for use with injection wells known as the C-SpargerTM system.
  • Said system consists of the following components: referring to the Figures 1 through 6 there is shown a Sparge System 10 consisting of multiple microporous diffusors in combination with an encapsulated multi-gas system, the system 10 consists of a master unit 12 and one or more in- well sparging units 14.
  • master unit 12 can operate up to a total of three wells simultaneously and treat an area up to 50 feet wide and 100 feet long. Actual performance depends upon site conditions. Vapor capture is not normally necessary.
  • master unit 12 consists of the following: a gas generator 16, a gas feed line 15, a compressor 18, a power source 19, a pump control unit 20, a timer 22.
  • the master unit 12 must be firmly mounted on 4 x 4 posts or a building wall near in- well sparging units 14.
  • a heavy-duty power cable 44 may be used to run from the power source to the master unit 12.
  • the in- ell sparging unit 14 consists of a casing 56, an inlet screen 50 an expandable packer 52, an upper site grout 54, an outlet screen 58, and lower grout 62.
  • Each in- well unit 14 includes a fixed packer 24, at least two diffusors 26 hereinafter "SpargepointTM diffusors" 26, a water pump 28, ozone line 30, check valve 32, and fittings.
  • the diffusor 26 employs a microporous diffusor in place of standard slotted well screen to improve dispersion of bubbles 60 through soil shown at 84 and improve rate of gaseous exchange.
  • a normal 10-slot PVC well screen contains roughly twelve percent (12%) open area. Under pressure most air exits the top slits and radiates outward in a starlike fracture pattern, evidencing fracturing of the formation. Referring to Fig.
  • FIG. 2 there is shown a fine bubble production chamber 46 positioned in the well casing 56 between the upper well screen 50 positioned immediately below fixed packer 24 consisting of a removable closure plug and the lower plug 48 consisting of the fine bubble production chamber 46 containing bubbles 60 including upper SpargepointTM 26 positioned above lower well screen 58 including pump 28 and check valve 32.
  • Fig. 4 there is shown the internal layout of the control module box 12 including an AC/DC power converter 71, and ozone generator 72, well gas relays 73 (three wells shown), a compressor 74, a master relay 75, a main fuse 76.
  • each spargepoint is bundled (spaghetti tube approach) or the spargepoints are constructed in a unique way which allows interval tubing connections with flow and pressure control for each spargepoint region.
  • the spargepoints pass through the spargepoint internally without interfering with function of producing small bubbles on a smooth external surface.
  • the tubing penetration reduces the internal gas volume of the spargepoint, thereby reducing residence time for oxidative gases (important since ozone has only a certain lifetime before decomposition), and allows 3 to 4 spargepoints to be operated simultaneously with equal flow and pressure.
  • Each spargepoint can also be programmed to pulse on a timed sequencer, saving electrical costs and allowing certain unique vertical and horizontal bubble patterns.
  • Spargepoint diffusors can be fitted with F480 Thread with internal bypass and compression fittings. This arrangement has the advantages that it fits standard well screen, allows individual flow/pressure control, reduces residence time, and allows casing/sparge instead of continuous bubbler
  • Injectable Points configured as Molded 18 Inch 40 inch HDPE molded into 1/4 inch pp tubing or HDPE tubing allows smooth tube to be inserted into push probe with detachable point
  • Rotometer/mirror Mirror assembly for flush-mounted rotometer (flowmeter) allows reading from vertical down, and controls flow off lateral lines to adjust to back pressure from varying types of formations (silt, sand, gravel) below
  • the use of microporous mate ⁇ als in the "SpargepointTM 26 to inject gases into groundwater saturated formations has special advantages for the following reasons 1 Matching permeability and channel size, 2 Matching porosity, and 3 Enhancing fluidity, which can be determined in-situ
  • the most effective range of pore space for the diffusor material selected depends upon the nature of the unconsolidated formation to be injected into, but the following serves as a general guide 1 Porosity of porous material thirty percent (30%), 2 Pore space 5-200 microns, a 5-20 very fine silty sand, b 20-50 medium sand, and c 50-200 coarse sand and gravel
  • the surrounding sand pack placed between the spargepoint 26 and natural material to fill the zone of drilling excavation should also be compatible in channel size to reduce coalescing of the produced bubbles
  • the permeability range for fluid injection function without fracturing would follow (1) 10 2 to 10 "6 cm/sec, corresponding to 2 to 2000 Darcy's, (2) 20 2 to 10 "6 cm/sec, or (3) 100 to 01 ft/day hydraulic conductivity
  • Permeability is the measure of the ease of movement of a gas through the soil
  • the ability of a porous soil to pass any fluid, including gas depends upon its internal resistance to flow, dictated largely by the forces of attraction, adhesion, cohesion, and viscosity Because the ratio of surface area to porosity increases as particle size decreases, permeability is often related to particle I EVALUATION TEST
  • the first step in preparing a site for treatment is to conduct an evaluation test to determine whether or not an aquifer has characteristics which make it suitable for treatment by the microbubble sparging system of the present invention
  • the test employs one or more microporous bubble generators known as SpargepointsTM which produce extremely fine bubbles and are sized to penetrate fine sands by matching the bubble size to the soil porosity
  • SpargepointsTM microporous bubble generators known as SpargepointsTM which produce extremely fine bubbles and are sized to penetrate fine sands by matching the bubble size to the soil porosity
  • ⁇ ng wells Prior to conducting an evaluation test, reconnaissance steps normally performed at a site include 1) soil coring to establish the extent of volatile organic carbon (vocn) contamination and 2) soil types with depth and hydrocarbon content Monito ⁇ ng wells are usually installed for later observation points, typically having well screens which extend five to seven feet below static water with one to three feet above, depending upon historic record of water level changes for the area If floating nonaqueous liquid petroleum is observed (greater than sheen thickness), efforts to remove the product should be undertaken prior to evaluation testing. Oil corings are commonly scanned with a PLD detector to establish the three-dimensional extent of petroleum contamination Subsamples can be forwarded to a laboratory to determine precise chemical composition
  • the next step is to prepare a site map, noting the distances between the test point and adjacent wells Immediately prior to conducting the test, check water elevation in monitoring wells and/or point piezometers
  • the following is a list of the materials and a stepwise procedure (see Figure 11) for conducting a sparge test with the micro-bubbler generator 3/4- ⁇ nch OD x 18 inch (for 5 inch ID schedule 90 PVC), Wellhead surface assembly, (1/4 inch connections, 0-2 5 cfrn), Gas tank regulator, (acetylene torch type, zero air or nitrogen, 0- 100 psi adjustable, 0-3 cfm flow capacity, male 1/4 inch NPT connector), Zero air tank (medium, 500 cf, 15600 to 2000 psi) 90 lbs , 1/4 inch compression fittings, 1/4 inch copper tube (See Figure 12 for assembly of parts )
  • C. Connect 1/4 inch compression fitting to wellhead stickup 0.5 inch PVC pressure cap (either glue or screw top to casing, leaving enough for later completion); D. Bring pressure down to 10 psi; (1) Slowly open valve b; (2) Check flow (yield) on flowmeter, in cfph (cubic ft. per hour). Divide by 60 to get cfm. (3) If yield is less than .3 cfm, increase pressure valve to 15 psi; maintain for 5 minutes, opening valve b to maximum flow (4) Maintain for 30 minutes if flow is near .5 cfm. (5) Check observation wells with electronic dip meter to record water levels at 15 minute intervals. Check surface with flashlight for bubbles reaching surface. Verify with transparent bailers.
  • the injection of air into an aquifer closely approaches Darcian flow, as long as fracturing pressures are not exceeded.
  • the initial bubble can be sized below or matching the interparticle pore space, allowing gas conductivity to more approximate fluid conditions (Kerfoot, 1993).
  • the injection of air then approximates the more familiar injection of water, exhibiting mounding and outward movement until equilibrium is reached.
  • bubbling occurs when the gas pressure overcomes the hydraulic head (depth of water from static elevations to bottom of bubbler), the line friction, the membrane resistance of the bubbler wall, and the back pressure of the formation.
  • the hydraulic head is converted to psi equivalents by multiplying depth of water by .43.
  • the resistance of a half (1/2) inch tube is negligible under ten feet.
  • the membrane resistance of a three quarter (3/4) inch bubble generator is roughly two psi.
  • the critical bubbling pressure would be the following:
  • the most crucial pressure to overcome is the formation back pressure which varies with the surface to volume relationship of the pore spaces and the extent of their occlusion by fines.
  • Gas is a fluid that, unlike water, is compressible. Vapor flow rates through porous material, such as soil, are affected by the material's porosity and permeability, as well as the viscosity, density, and pressure gradient of the gas. The movement of gas through soil can be approximated by Darcy's law.
  • a simple formulation of Darcy's law for saturated gas flow in one dimension is:
  • V n An un where:
  • V seepage velocity (cm/sec)
  • V gas yield (cm 3 )/ (cm 2 )(sec))
  • q flow rate (cm 3 /sec)
  • k gas permeability (cm 2 ) (Darcies)
  • A cross-sectional area (cm 2 )
  • u viscosity (g/(cm)(sec))
  • dP/dm pressure gradient (g/cm)(sec 2 )/cm
  • n specific porosity (i.e., void nonwetted volume)
  • Darcy is defined as the permeability that will lead to a specific discharge (v) of 1 cm/sec for a fluid with a viscosity of 1 centipoise under a pressure gradient that makes the term pg/u (dp/dl) equal to 1 atmosphere, where p is density, u viscosity, and g is the force of gravity.
  • A cross-sectional flow area (ft 2 )
  • a normal 10-slot PVC well screen contains roughly twelve percent (12%) open area. Under pressure most air exits the top slits and radiates outwards in a starlike fracture pattern, evidencing fracturing of the formation.
  • the effectiveness of treatment is dependent upon uniformity of dispersion of the gas as it travels through the formation.
  • a porous structure with appropriate packing matches the condition of the pores of the soil with thirty percent (30%) pore distribution.
  • the dispersion of bubbles as a fluid can be checked with Darcy's equation.
  • the use of microporous materials to inject gases into groundwater saturated formations has special advantages for the following reasons: (1) Matching permeability and channel size: (2) Matching porosity; (3) Enhancing fluidity, which can be determined in-situ.
  • Pore Space 5-200 microns: (a) 5-20 very fine silty sand; (b) 20-50 medium sand; (c) 50-200 coarse sand and gravel.
  • the surrounding sand pack placed between the bubble generator and natural material to fill the zone of drilling excavation should also be compatible in channel size to reduce coalescing of the produced bubbles.
  • the permeability range for fluid injection function without fracturing would follow: (1)
  • Permeability is the measure of the ease of movement of a gas through the soil.
  • the ability of a porous soil to pass any fluid, including gas, depends upon its internal resistance to flow, dictated largely by the forces of attraction, adhesion, cohesion, and viscosity. Because the ratio of surface area to porosity increases as particle size decreases, permeability is often related to particle size, see Figure 9.
  • EQUIPMENT 1 Unique Microporous Diffusors - types a. Direct substitute for well screen, 30% porosity 5-50 micron channel size resistance to flow only 1 to 3 psi, can take high volume flow, need selective annular pack (sized to formation). High density polyethylene or polypropylene is light weight, inexpensive. b. Diffusor on end of narrow diameter pipe riser KVA 14-291. This reduces the residence time in the riser volume. c. Shielded microporous diffusor which is injected with a hand-held or hydraulic vibratory hammer. The microporous material is molded around an internal metal (copper) perforated tubing and attached to an anchor which pulls the bubble generator out when the protective insertion shaft is retracted.
  • Thin Spargepoint bubble generators with molded tubing can be inserted down narrow shaft for use with push or vibratory tools with detachable points. The shaft is pushed to the depth desired, then the bubble generator inserted, the shaft is pulled upwards, pulling off the detachable drive point and exposing the bubble generator.
  • Microporous diffusor/pump combination placed within a well screen in such a manner that bubble production and pumping is sequenced with a delay to allow separation of large bubbles from the desired fine "champagne" bubbles. The pressure from the pump is allowed to offset the formation back pressure to allow injection of the remaining fine bubbles into the formation.
  • the back pressure from the aquifer and radius of bubbling represent some of the major unknowns in the sparging system field design.
  • the following test was designed and field tested to evaluate the capacity of the aquifer for sparging and to provide critical design information.
  • a microporous bubbler of known characteristics is placed by injection or hollow stem auger a fixed distance below static water.
  • a gas tank zero air or nitrogen
  • a flowmeter provides the source of gas.
  • the pressure is increased in a stepwise manner while observing flow.
  • the yield versus pressure is then recorded.
  • the shape of the curve indicates the pressure range of normal formation acceptance of flow under Darcian conditions and non
  • the gas flow to the bubble generator (Spargepoint®) also increases (see Figure 13).
  • the gas yield (flow) was measured with the bubbler in air, the main resistance being through the porous sidewalls of the cylinder.
  • the resistance to flow may be so low that a shallow curve of pressure versus flow occurs. If so, assume that the radius of bubbling will increase by the square root of 2 (i.e., 1.4) times each time the flow volume is doubled.
  • Critical bubbling pressure pressure to initiate bubbling
  • Pc (psi) [0.43 x depth below water (ft)] + 3.5 (psi).
  • Input bubble generator depth below static groundwater level. 10.0 (ft);
  • Critical bubbling pressure is calculated as 6.0 (psi);
  • Critical bubbling radius is calculated as 20.0 (ft); Input proposed delivery pressure to spargepoints 12 (psi);
  • Bubbling zone radius based on input pressure 12.0 and volume (20 scfrn) . . . . 30 (ft);
  • the microsparge process involves generation of fine bubbles which can enter and pass through the torturous pathways of the substrate (aquifer structure) and promote rapid gas/gas/water reactions with volatile organic compounds which the substrate participates in, instead of solely enhancing dissolved (aqueous) disassociations and reactions.
  • the microsparging process encompasses the following unique aspects:
  • the injected air/water combination moves as a fluid through the aquifer without fracturing or channeling, which interfere with even distribution and efficiency of exchange.
  • the injected gas/water combination is pulsed in such a way to move the bubbles on a pressure wave for lateral distribution.
  • the wave form has an amplitude which falls above critical bubbling pressure but below fracturing pressure for formation.
  • the pulsing is done to create short-term tidal waves in three dimensions.
  • the combination of recirculating the water also assists in creating and promoting vertical airlift which induces the generation of a three-dimensional eddy current adjacent to the spargewell, greatly assisting in evening the reaction rate throughout a broad aquifer region.
  • Remote Process Controller and Monitor This allows for the capacity for sensor feedback and remote communication to the Timer/Sequencer ozone (or oxygen or both) generator to achieve a certain level of gaseous content (e.g., dissolved oxygen, ozone, or other gas) and rate of mixing to promote efficient reactions. This is done by sensors placed in monitoring wells at certain distances from the central spargewell. A groundwater flow meter and pressure sensor monitors rate and direction of rotation of a three-dimensional gyre (or eddy) produced by pulsing the unit. The unique combination of pressure and flow allows a quick determination of where and how fast mixing will occur.
  • gaseous content e.g., dissolved oxygen, ozone, or other gas
  • Oxygen content, redox potential, and dissolved VOC concentration of the water can be monitored at a nearby monitoring well or top well screen of the spargewell.
  • the operator can access the information, modify operations and diagnose the condition of the unit by telephone modem or satellite cell phone. This provides on-site process evaluation and adjustment without operator presence.
  • microfine bubbles substantially accelerate the transfer rate of volatile organic compounds like PCE from aqueous to gaseous state.
  • the bubble rise has the potential to transfer the PCE to the watertable surface and above (vadose zone).
  • the ten-fold difference in surface-to-volume ratio of bubble generator (Spargepoint®) microbubbles compared to bubbles from well screens results in at least four-fold improvement in transfer rates.
  • the microporous bubbles exhibit an exchange rate of ten times the rate of a comparable bubble from a standard ten slot well screen.
  • the loss of efficiency from spherical to elongate cylinder can be shown by contrasting the ratios of transforming from one quarter (1/4) pore size (given as 1 0) to ten (10) times pore size for a constrained gas bubble
  • pore size given as 1 0
  • A/V ratio of 24
  • the ratio decreases to an A/V ratio of six (6)
  • the bubble volume becomes larger it is forced to elongate into a cylinder
  • the A/V ratio shrinks further and begins to converge between 2 0 and 4 0
  • the surface to volume ratio has reduced to about one-twelfth (spheroid) or one-sixth (cylinder) of that found with spherical (or mini-cylinders) of one quarter
  • CYLINDER (diameter is constant at 1 0, for h g reater than 1
  • the two-film theory of gas transfer states the rate of transfer between gas and liquid phases is generally proportional to the surface area of contact and the difference between the existing concentration and the equilibrium concentration of the gas in solution. Simply stated, if we increase the surface to volume ratio of contact, we increase the rate of exchange. If, secondly, we consume the gas (VOC) entering the bubble (or micropore space bounded by a liquid film), the difference is maintained at a higher entry rate than if the VOC is allowed to reach saturation equilibrium.
  • VOC gas
  • A area through which gas is diffusing
  • Soil vapor concentrations are related to two governing systems: water phase and (non-aqueous) product phase.
  • Henry's, and Raoult's Laws (DiGiulio, 1990) are commonly used to understand equilibrium-vapor concentrations governing volatization from liquids. When soils are moist, the relative volatility is dependent upon Henry's Law. Under normal conditions (free from product) where volatile organic carbons (VOCs) are relatively low, an equilibrium of soil, water, and air is assumed to exist.
  • VOCs volatile organic carbons
  • PCE tetrachloroethene
  • Figure 15 plots a curve of the removal rate of PCE for an aqueous solution equivalent to 120 ppb, subjected to differing bubble sizes. The air volume and water volume was held constant. The only change was the diameter of bubbles passed through the liquid from air released from a diffusor.
  • XIV. PCE REMOVAL RATE AS FUNCTION OF BUBBLE SIZE OZONE ENCAPSULATION - C-SPARGINGTM
  • Ozone is an effective oxidant used for the breakdown of organic compounds in water treatment. The major problem in effectiveness is a short lifetime. If ozone is mixed with sewage containing water above ground, the half-life is normally minutes. Ozone reacts quantitatively with PCE to yield breakdown products of hydrochloric acid, carbon dioxide, and water.
  • the ozone could be injected with microporous diffusors, enhancing the selectiveness of action of the ozone.
  • vdx/dt K v (Q-X) which is the ratio between the amount of substance entering the given volume per unit time and quantity V (Q-X) needed to reach the asymptotic value.
  • the rate which the quantity K,QV of the substance flows in one unit of time from aqueous solution into the bubble is proportional to Henry's Constant.
  • the unique combination of microbubble extraction and ozone degradation can be generalized to predict the volatile organic compounds amenable to rapid removal.
  • the efficiency of extraction is directly proportional to Henry's Constant. Multiplying the Henry's Constant (the partitioning of VOCs from water to gas phase) times the reactivity rate constant of ozone for a particular VOC yields the rate of decomposition expected by the microbubble process.
  • the concentration of HVOC expected in the bubble is a consequence of rate of invasion and rate of removal.
  • the ozone concentration is adjusted to yield 0 concentration at the time of arrival at the surface.
  • the saturation concentration of a VOC in wastewater is a function of the partial pressure of the VOC in the atmosphere in contact with the wastewater.
  • H c Henry's Constant The rate of decomposition of an organic compound C g , (when present at a concentration
  • Rate of decomposition is now adjusted to equal the total HVOC entering the bubble.
  • P CJ - Ko OJtCJ equation 5
  • Table 4 gives the Henry's Constants (H c ) for a selected number of organic compounds and the second rate constants (RJ for the ozone radical rate of reaction observed in solely aqueous reactions where superoxide and hydroxide reactions dominate.
  • H c Henry's Constants
  • RJ rate constants
  • the eligible compounds for the C-SpargerTM process are normally unsaturated (double bond), halogenated compounds like PCE, TCE, DCE, Vinyl Chloride, EDB, or aromatic ring compounds like benzene derivatives (benzene, toluene, ethylbenzene, xylenes).
  • halogenated compounds like PCE, TCE, DCE, Vinyl Chloride, EDB
  • aromatic ring compounds like benzene derivatives (benzene, toluene, ethylbenzene, xylenes).
  • Criegee reactions with the substrate and ozone appear effective in reducing certain saturated olefins like trichloro alkanes (1,1-TCA), carbon tetrachloride (CC1 4 ), and chlorobenzene, for instance
  • XVI. SITE DESCRIPTION The field test is positioned in a small park area midway on a long plume of predominantly trichloroethene (TCE) originating at a commercial building and traveling over 800 ft. across a predominantly commercial and residential area.
  • TCE trichloroethene
  • the plume region lies in a thick fine sand deposit which contains gravel (streambed) deposits.
  • Groundwater exists at a depth of 7.5 ft. (2.5 m) below grade. About one half of the area of groundwater overlying the TCE plume is contaminated with dissolved hydrocarbons (BTEX) from a nearby commercial fuel spill. Soil borings taken by Tauw Engineering in the vicinity of the plume showed a shallow surface loam extending to 6 feet (2 m) deep.
  • the location of the monitoring wells were varied in distance and depth from the test spargewell (TW) to be able to give a 3 -dimensional picture of the test results.
  • the larger diameter (2-inch ID) wells allowed groundwater flow measurements as well as pressure change to be monitored during treatment. A variety of physical and chemical measurements were performed during the test. TABLE 5. GROUNDWATER MONITORING DURING PILOT TEST
  • Groundwater Flow HVOCs including PCE, TCE, DCE, Vc, DCA
  • VOCs including benzene, toluene, xylenes, ethylbenzene, ozone concentration
  • the C-SpargerTM double-screen well with lower bubble generator was installed with a recirculating water system and casing. A small flow (2 gal min) was obtained from a shallow fire well for makeup water.
  • the lower bubble generator was set at a depth of 7.8 ft. (2.6 m).
  • a one-half inch tubing extended to the surface from a compression fitting on the bubble generator.
  • a four inch ID triple-screened well extended from 69 ft. (23 m) to one foot above grade. 6 ft. long
  • the middle casing between the two lower screens received 3 ft ( 1 m) of bentonite grout, 3 ft ( 1 m) of cement bentonite, and 3 ft. (1 m) of bentonite to seal the annular space to prevent "short-circuiting" of water. Water and fine bubbles are injected into the formation from the lowest screen and return water enters the middle screen. The uppermost screen collects gases from just above the water table (2.5 m) to assure vapor control
  • the C-SpargerTM system is designed to achieve the injection and distribution of microbubbles into the aquifer to be treated.
  • the injection of the air/ozone approximates the injection of water, exhibiting mounding and outward movement until equilibrium is reached.
  • Tables 6 and 7 give the results of field measurements taken during sampling.
  • the bubble zone was still expanding during the ten day test. Based upon the time sequence, a long axis extending outwards about 100 ft. (30 m) in a westerly and easterly direction would be reached, with a minor axis (at right angles) of about 56 ft. (18 m). Each well would then treat a region 200 ft. long by about 100 ft. wide and 90 ft. (30 m) deep. Although an elliptic zone is considered here, the occurrence of bubbles at miniwell 126 about day 5 complicates the picture.
  • the outward gyre would reach a maximum velocity at about 36 ft. (12 m).
  • the vertical eddy for mixing appeared to reach a velocity with a diameter of about 60 ft. (20 m) by day 10 of the test, with an estimated velocity of about 10 ft/day (3.3 m/d). This is slow by normal standards and probably the result of loss of pressure along the narrow gravel streambed, intercepted between 60 ft. and 75 ft. deep (20 and 25 m).
  • HVOCs HVOCs
  • Wells TM, D, 129 Concentration of HVOCs (VOCs) located in the gravel zone underwent immediate rapid reduction (wells TM, D, 129).
  • Wells TM, D, 129 Nearby wells located at right angles (probably in fine sands) to the buried gravel streambed, showed a slower removal, converging on a logarithmic decay rate.
  • Those in the outlying wells mainly requiring recirculation to treat the groundwater, tended to show decaying oscillating concentrations with time, reflecting the circular water movement.
  • Elimination and detoxification processes correspond to first order reactions where the rate of decrease in concentration of the toxic substance is directly proportional to the concentration of the substance.
  • t 1/2 corresponds to the length of time needed for the concentration of Co to decrease by 50% ; i.e.. t 1/2 is the half-life of the substance in the groundwater.
  • HVOC removal rates fell between .09 and .14t.
  • BTEX removal rates fell between .07 and
  • the time to bring core region concentrations to 1 ⁇ g/l-ppb ranged from 50 to 100 days.
  • the level ranged between 20 to 60 days.
  • the HVOC removal rate is somewhat slower since the beginning concentration of 2000 ppb total HVOC is higher than the starting point of the BTEX compounds (50-70 ppb)
  • BUBBLE CHAMBER SELECTOR AND INJECTOR
  • a recirculating liquid flow system under pressure was combined with a porous cylinder, with counter-gravity flow (for segregating bubble size) to create a micro-bubble production chamber.
  • the combination of flow across porous plates has been known to fractionate bubbles to produce small bubbles (Adler, Bourbigot, and M. Faivre, 1985).
  • the partial water flow was pressurized, saturated with ozone and then released, producing fine bubbles with a size between 50 to 200 ⁇ m (Boisoon, Faivere, and Martin, 1995).
  • step A generation of a large range of bubble sizes at one time
  • step B the segregation step when larger bubbles segregate out and form a gas space at the top
  • step C the fine bubbles remaining are then pumped out the lower well screen as water under pressure is introduced from the top.
  • INDUCTION OF MICROBUBBLE MOVEMENT The induction of microbubble flow through a sandy saturated deposit (aquifer) can be compared to that of transferring electron movement through alternating current. An alternating wave of pressure is created where the amplitude varies continuously.
  • P ma the maximum pressure in inches (cm) of water
  • ⁇ the angle at which pressure is being calculated
  • the pulsing pressure wave can be seen at distance from the C-SpargerTM well (figure 33). Cycle time can vary from 30 minutes to 10 minutes.
  • Microbubbles being less dense than water, will tend to rise, resulting in a parabolic upwards pathway.
  • the rising rate (velocity) produces a displacement of water upwards which creates an inflow of lower water, inducing an eddy and mixing with a particular radius of the installed spargewell.
  • the lateral extent of treatment depends upon the distance between the lower bubble generator and the topmost well screen. Generally, the cross-sectional area of influence is about 2.5 times the vertical distance between the lower sparge bubble generator and the upper screen.
  • the mixing capacity of recirculation allows mechanics to be used equivalent to Diffused-Air Aeration Process Mechanics.
  • the three-dimensional recirculation cell can be considered similar to the boundaries of a tank (figure 35). If groundwater flow is very slow, the cell is considered a fixed reactor with only circulation and no inflow. If groundwater movement is significant, the transfer into the cell is equivalent to inflow and the loss of groundwater downgradient, the discharge effluent.
  • the C-SpargerTM unit is equipped with a telephone modem diagnostic sensor unit and monitoring well sensor which feed back to the sequencer to control the groundwater/soil remediation process.
  • a remote unit can then monitor the extent of treatment and induced groundwater mixing and determine when to move to another spargewell.
  • An operator can dial the unit and receive past and ongoing data on groundwater condition and machine operation. The recorded data can be dumped for graphic presentation.
  • the rise time of bubbles of different sizes was computed for water, giving the upwards gravitational velocity.
  • the upwards velocity provides the positive pressure to push the bubbles through the porous media, following Darcy's equation.
  • the actual rise time is dependent upon the size of the bubble, the frequency of agritation (pulsing) and pressure differential during pulses.
  • the rise time proportional to upwards pressure, can be calculated.
  • rise time in medium to coarse sand based upon 15 minute pulse cycles of generation with an equivalent pressure differential of 20 psi at the source, .5 ft. change at 30 ft. radius from generation (Table 7).
  • the reaction of ozone and PCE in the air bubbles is a gas reaction.
  • the molecular weight of PCE is 168 gm/mole; ozone is 48 gm/mole.
  • a mass of 3.5 grams of PCE reacts with one gram of 0 3 needed to react with 1 mole PCE.
  • the total mass of dissolved PCE in the treated water column is computed. Assuming a porous cylinder of 8 meters radius and 2 meters deep (contaminated zone), the liquid volume of medium sand (.30 porosity) is about 60,000 liters.
  • reaction rate is dependent upon the total number of bubbles (area of extraction), the efficiency of distribution of the bubbles, and the rate of transfer into the bubbles
  • rate of decomposition within the bubbles is a ratio proportional to concentration, i.e., it slows as concentration decreases.
  • XXV ⁇ i USE OF SPECIALLY-DESIGNED WELLHEADS
  • a resistance element like a needle valve, may be placed inline with a flowmeter to allow the flow to be equalized to each point.
  • the capacity to maintain pressure at the wellhead is simultaneously measured by a pressure gauge.
  • the wellheads are often installed at the top of the bubble generator to limit the number of individual lines back to the compressor/ozonator. Placed in a wellhead, a vertical mount block flow meter cannot be easily read. To allow easy reading, a 45 degrees angle mirror was installed and the scale printed in mirror image to allow for easy reading.
  • the simplest sparging system attaches ten or twenty sparging points to one gas supply
  • the individual flow controllers adjust each sparging point for even air flow and sparging.
  • a zone control system adds an electronic or mechanical programmable timer that opens and closes valves to direct the air supply to the appropriate manifold.
  • the zone control is added to the system to expand the system and improve control of the sparging. Sequential periods of aeration improve the sparging action and expand the capabilities of a single air source for the system. If, for example, one microfine sparge system can provide adequate gas supply to 10 sparge bubblers, zone control can increase this to 20, 30 or more.
  • Concentric zones of sparging centers activated for different lengths of time and volumes of air, will form a barrier to off-site product migration.
  • a contaminated region with overlapping zones of sparging contains a plume.
  • the midpoint of Region A is located just outside the contaminated zone.
  • the sequence of sparging involves first zone A, then zone B, and finally zone C. Greater volume and/or duration of sparging in zone A forms a barrier ridge, forcing product toward the center of zone C.
  • Figure 21 Individual sparge bubble generator effects are shown graphically as the location of introduced bubbles in the saturated zone.
  • the shape of the bubbled zone is composed of the original groundwater zone plus an area above static water level where water is mounded and is governed by the air pressure and volume. Higher pressure and greater volume gives a wider diameter of influence while lower pressure and lower volume influence a smaller diameter area.
  • the function of the inverted pump also adds two additional advantages to normal microbubble production: (1) the periodic outwards pressure enlarges the bubble radius over that of a microporous point alone and, (2) the alternating of water pulsing after bubble production decreases the formation of air channels which tend to enlarge with continual air injection

Landscapes

  • Treatment Of Water By Oxidation Or Reduction (AREA)

Abstract

Le procédé et l'appareil faisant l'objet de cette invention, qui servent à l'assainissement de l'eau souterraine, ont recours à des diffuseurs microporeux pour éliminer la contamination, constituée notamment par les hydrocarbures chlorés dissous et par les produits pétroliers à base d'hydrocarbures dissous, ainsi qu'à des puits d'injection composés de générateurs de fines microbulles, adaptés aux substrats des régions aquifères sélectionnées, afin d'injecter et de distribuer ces bulles, contenant un gaz oxydant, à travers la nappe aquifère et afin d'encapsuler sélectivement les gaz tels que l'oxygène et l'ozone dans des bulles à deux gaz qui, en présence du matériau de substrat coréactif agissant comme catalyseur, ont pour effet de stimuler la biodégradation des panaches de lixiviat qui contiennent des substances organiques biodégradables ou de stimuler la décomposition Criegee des panaches de lixiviat contenant des hydrocarbures chlorés dissous, ledit matériau de substrat agissant comme coréactif avec le gaz, en vue de décomposer les composés organiques volatils par une réaction gaz/gaz/eau. Ledit appareil comprend plusieurs puits d'injection s'étendant jusqu'à une certaine profondeur d'une nappe aquifère sélectionnée; cet appareil fonctionnant en introduisant un agent oxydant comprenant de l'ozone mélangée à de l'air ambiant pour former un gaz multi-élément au moyen de diffuseurs microporeux, sans appliquer de dépression pour obtenir l'extraction de produits séparés ou la biodégradation de sous-produits, lesdits diffuseurs formant de fines microbulles contenant ce gaz multi-élément, lequel oxyde, par séparation et décomposition, les hydrocarbures chlorés en les séparant de la nappe aquifère, ainsi que les formations géologiques saturées circonvoisines, pour les transformer en sous-produits inoffensifs; cet appareil comprenant également une pompe agitant l'eau dans le puits et injectant les microbulles dans la nappe aquifère, ce qui modifie la trajectoire des fines microbulles à travers une formation solide poreuse, de sorte que le contact accru entre l'agent oxydant contenu dans chaque microbulle par séparation des agents polluants de la solution dans l'eau ambiante à l'intérieur de la mini-atmosphère de chaque bulle a pour effet d'accroître l'efficacité et la vitesse d'assainissement d'un site.
EP97913956A 1996-11-15 1997-10-29 Assainissement de l'eau souterraine a l'aide de diffuseurs microporeux Ceased EP0946431A1 (fr)

Applications Claiming Priority (7)

Application Number Priority Date Filing Date Title
WOPCT/US96/01846 1996-11-15
PCT/US1996/018464 WO1997039984A1 (fr) 1996-04-25 1996-11-15 Procede et appareil permettant la biorestauration souterraine
US756273 1996-11-25
US08/756,273 US5855775A (en) 1995-05-05 1996-11-25 Microporous diffusion apparatus
US08/921,763 US6312605B1 (en) 1995-05-05 1997-08-26 Gas-gas-water treatment for groundwater and soil remediation
US921763 1997-08-26
PCT/US1997/019907 WO1998021152A1 (fr) 1995-05-05 1997-10-29 Assainissement de l'eau souterraine a l'aide de diffuseurs microporeux

Publications (1)

Publication Number Publication Date
EP0946431A1 true EP0946431A1 (fr) 1999-10-06

Family

ID=56289799

Family Applications (1)

Application Number Title Priority Date Filing Date
EP97913956A Ceased EP0946431A1 (fr) 1996-11-15 1997-10-29 Assainissement de l'eau souterraine a l'aide de diffuseurs microporeux

Country Status (3)

Country Link
EP (1) EP0946431A1 (fr)
AU (1) AU5101098A (fr)
CA (1) CA2271844C (fr)

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109710959A (zh) * 2018-08-23 2019-05-03 上海市水利工程设计研究院有限公司 一种水资源引清调度水体置换效果数值模拟方法
CN110090856A (zh) * 2019-03-26 2019-08-06 清华大学 土壤地下水联动处理装置及其处理方法
CN110220743A (zh) * 2019-06-28 2019-09-10 苏州中车建设工程有限公司 一种便携式取水装置
CN110220742A (zh) * 2019-06-28 2019-09-10 苏州中车建设工程有限公司 一种野外定深快速取水方法
CN110369481A (zh) * 2019-07-02 2019-10-25 南华大学上虞高等研究院有限公司 一种铀污染土壤多级修复用预埋包及其使用方法
CN115477392A (zh) * 2022-10-28 2022-12-16 中絮生物技术(武汉)有限公司 一种基于同时硝化反硝化的立体叠层生化处理装置及工艺方法

Families Citing this family (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN106807736B (zh) * 2017-03-01 2022-03-01 北京建工环境修复股份有限公司 一种土壤及地下水固相浅层搅拌原位化学氧化修复方法
CN109271675B (zh) * 2018-08-24 2023-03-17 中煤科工集团西安研究院有限公司 单指数模型矿区生态临界地下水位动态预测方法及装置
CN110304668B (zh) * 2019-07-02 2021-12-28 太原理工大学 一种可调节地下水修复药剂注入深度的自动控制装置

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5167806A (en) * 1990-07-03 1992-12-01 International Environmental Systems, Inc. Gas dissolving and releasing liquid treatment system
US5205927A (en) * 1987-09-25 1993-04-27 Battelle Memorial Institute Apparatus for treatment of soils contaminated with organic pollutants
WO1997039984A1 (fr) * 1996-04-25 1997-10-30 K.V. Associates, Inc. Procede et appareil permettant la biorestauration souterraine

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5205927A (en) * 1987-09-25 1993-04-27 Battelle Memorial Institute Apparatus for treatment of soils contaminated with organic pollutants
US5167806A (en) * 1990-07-03 1992-12-01 International Environmental Systems, Inc. Gas dissolving and releasing liquid treatment system
WO1997039984A1 (fr) * 1996-04-25 1997-10-30 K.V. Associates, Inc. Procede et appareil permettant la biorestauration souterraine

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
See also references of WO9821152A1 *

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109710959A (zh) * 2018-08-23 2019-05-03 上海市水利工程设计研究院有限公司 一种水资源引清调度水体置换效果数值模拟方法
CN109710959B (zh) * 2018-08-23 2023-08-18 上海市水利工程设计研究院有限公司 一种水资源引清调度水体置换效果数值模拟方法
CN110090856A (zh) * 2019-03-26 2019-08-06 清华大学 土壤地下水联动处理装置及其处理方法
CN110220743A (zh) * 2019-06-28 2019-09-10 苏州中车建设工程有限公司 一种便携式取水装置
CN110220742A (zh) * 2019-06-28 2019-09-10 苏州中车建设工程有限公司 一种野外定深快速取水方法
CN110220742B (zh) * 2019-06-28 2021-06-15 苏州中车建设工程有限公司 一种野外定深快速取水方法
CN110220743B (zh) * 2019-06-28 2021-06-15 苏州中车建设工程有限公司 一种便携式取水装置
CN110369481A (zh) * 2019-07-02 2019-10-25 南华大学上虞高等研究院有限公司 一种铀污染土壤多级修复用预埋包及其使用方法
CN115477392A (zh) * 2022-10-28 2022-12-16 中絮生物技术(武汉)有限公司 一种基于同时硝化反硝化的立体叠层生化处理装置及工艺方法

Also Published As

Publication number Publication date
CA2271844C (fr) 2007-02-20
CA2271844A1 (fr) 1998-05-22
AU5101098A (en) 1998-06-03

Similar Documents

Publication Publication Date Title
US6827861B2 (en) Gas-gas-water treatment system for groundwater and soil remediation
US6312605B1 (en) Gas-gas-water treatment for groundwater and soil remediation
US5855775A (en) Microporous diffusion apparatus
US6306296B1 (en) Groundwater and soil remediation with microporous diffusion apparatus
US8302939B2 (en) Soil and water remediation system and method
AU679482B2 (en) Removing VOCs from groundwater
EP1315675B1 (fr) Procede de biorestauration d'aquiferes
CA2108128A1 (fr) Separation des composes organiques volatils contenus dans les eaux souterraines
Gvirtzman et al. The concept of in-situ vapor stripping for removing VOCs from groundwater
US7666316B2 (en) Permanganate-coated ozone for groundwater and soil treatment with in-situ oxidation
US6818136B1 (en) Groundwater remediation system
CA2271844C (fr) Assainissement de l'eau souterraine a l'aide de diffuseurs microporeux
EP0851843B1 (fr) Procede et appareil permettant la biorestauration souterraine
USRE43350E1 (en) Microporous diffusion apparatus
AU661321C (en) Removing volatile organic compounds from groundwater
Chao Aqueous-vapor phase mass transfer of VOCs in saturated porous media under air sparging conditions
Abouodah An innovative, effective and cost-efficient soil and groundwater remedial system

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 19990514

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AT BE CH DE DK ES FR GB GR IE IT LI LU NL PT SE

17Q First examination report despatched

Effective date: 20001120

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION HAS BEEN REFUSED

18R Application refused

Effective date: 20030523