EP1144315A1 - Biological permeable barrier to treat contaminated groundwater using immobilized cells - Google Patents
Biological permeable barrier to treat contaminated groundwater using immobilized cellsInfo
- Publication number
- EP1144315A1 EP1144315A1 EP00978309A EP00978309A EP1144315A1 EP 1144315 A1 EP1144315 A1 EP 1144315A1 EP 00978309 A EP00978309 A EP 00978309A EP 00978309 A EP00978309 A EP 00978309A EP 1144315 A1 EP1144315 A1 EP 1144315A1
- Authority
- EP
- European Patent Office
- Prior art keywords
- tcp
- pva
- columns
- gac
- immobilized
- 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
Links
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/10—Reclamation of contaminated soil microbiologically, biologically or by using enzymes
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B09—DISPOSAL OF SOLID WASTE; RECLAMATION OF CONTAMINATED SOIL
- B09C—RECLAMATION OF CONTAMINATED SOIL
- B09C1/00—Reclamation of contaminated soil
- B09C1/002—Reclamation of contaminated soil involving in-situ ground water treatment
-
- C—CHEMISTRY; METALLURGY
- C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
- C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
- C02F2103/06—Contaminated groundwater or leachate
Definitions
- This invention relates to biological permeable barriers for creating a "bio-trench” or “bio-curtain” to clean contaminated groundwater.
- the present invention relates to an apparatus and method to biodegrade contaminates in groundwater as the groundwater contacts and passes through the immobilized cells of the "bio-trench” or “bio-curtain” during groundwater flow or movement.
- permeable barriers An alternative to conventional groundwater treatment processes is the use of barriers which are permeable to water, but prevent the migration of contaminants. They are referred to as permeable barriers.
- In-situ permeable barriers are a relatively new cost-effective technology that can be used in groundwater remediation of shallow aquifers.
- Permeable barriers are installed as permanent, semi-permanent, or replaceable units across the flow path of a contaminant plume. Permeable barriers allow water to move passively through while precipitating, sorbing, or degrading the contaminants.
- These mechanically simple barriers may contain metal-based catalysts for degrading volatile organics, chelators for immobilizing metals, nutrients and oxygen for microorganisms to enhance bioremediation, or other agents.
- Degradation reactions may break down the contaminants in the plume into harmless byproducts.
- Crushed limestone, peat, and powdered activated carbon are also several effective barrier mediums that have been used to adsorb or precipitate contaminants. Advantages of these barriers include the following: simple installation, simple recovery and replacement of the material, low operation maintenance, less surface disruption, less labor, and less energy are required than other remediation technologies; and comparatively quick installation and containment of contaminants.
- non-biological permeable barrier is a mixture of powdered activated carbon (PAC) and sand.
- PAC powdered activated carbon
- sand a mixture of powdered activated carbon
- the PAC/sand mixture has been shown to be a successful medium for benzene removal in trench-based permeable barrier.
- the physical uptake of different mixtures (3% and 10%) of PAC/sand and nonabsorbent material such as sand and zeolite have been used.
- Another non-biological permeable barrier containing an iron-based catalyst has been used to reduce the concentration of trichloroethene (TCE) by 95% and the tetrachloroethene (PCE) concentration by 91%.
- TCE trichloroethene
- PCE trachloroethene
- Rael evaluated possible permeable barrier media designed to remove benzene in-situ from ground water. Effectiveness of several common material including coal, powdered-activated carbon (PAC), peat, and zeolite were evaluated in a series of batch and column studies with an initial benzene concentration of 50 mg/L. Silica sand was used as an inert matrix and was mixed with PAC to produce either 3 % (by weight) or 10 % PAC/sand mixtures. Based on their results, a mixture of PAC and sand was considered the most successful candidate. However, these authors observed that when the barrier reached its treatment capacity it had to be replaced with fresh media. The barrier medium allowed the flow of contaminated water but adsorbed the contaminant preventing further migration. This technology is limited to the depth accessible by trenching equipment and therefore would be applicable in shallow aquifer systems of less than 30 m.
- Bioremediation One known method to completely destroy the contaminants into the harmless by products. in the water is biological degredation. Biological processes are carried out by bacterial species that are capable of using organic compounds as their carbon source. Because of numerous advantages of biological processes, bioremediation has emerged as a viable technology to use microorganisms as effective agents to remove organic compounds from groundwater. The most common approach for large-scale bioremediation has been to inject nutrients into the ground water to simulate contaminant-degrading organisms. This approach has not proven to be reliable due to biofouling the stimulated population and contaminants into contact.
- bioagugmentation involves the addition of bactera and nutrients to contaminated ground water.
- the microorganisms are exposed to the stress conditions in the environment where they are introduced.
- the losses of viable microorganisms as a result of stress conditions and migration of microorganisms are the major problems with this technology. Inadequate controls over the microorganisms under specific environmental conditions limit the biological process and result in incomplete contaminant transformation.
- Cell immobilization can be defined as any technique that limits the free movement of cells. Cell mobility can be restricted by aggregating the cells or by confining them into, or attaching them to, a solid support. Historically, immobilized cells have been widely used in the wastewater treatment industry, generally through the use of undefined mixed cultures immobilized by natural flocculating tendencies or as films on solid surfaces. Polyvinyl alcohol has proved to be a useful means of immobilization of cells. PVA-immobilization of cells is the entrapment of microorganisms within a porous polymeric matrix of polyvinyl alcohol. The porous matrix captures the microorganism cell and allows diffusion of contaminate substrates toward the cells where they can be metabolized by the cells. The matrix also permits metabolism products the pass from the entrapped microorganisms. It has been determined that entrapped microorganisms are protected against the effects of toxic chemicals compared to free cells.
- Granular Activated Carbon(GAC) immobilization of cells is the attachment or adsorption of microorganisms on the surface of activated carbon.
- the activated carbon operates like a "buffer and depot.” It protects the microorganisms and sets low quantities of toxicant for biodegradation.
- activated carbon allows storage of substances that are difficult to biodegrade. Such storage provides a longer contact time between the microbial population and the substrates and could promote microbial acclimation and subsequent biodegradation.
- the polymeric materials tested included cellulose triacetate (mono-carrier), polyacrylamide, K-carrageenan and a combination of cellulose triacetate and calcium alginate (bi-carrier).
- the mono-carrier was used to determine long term operational performance because it had better mechanical strength.
- the bi- carrier was more porous and more elastic than the mono-carrier. It was determined that K-carrageenan and calcium alginate were weak in mechanical strength.
- Immobilized Pseudomonas sp. in alginate and polyacrylamide-hydrazide (PAAH) has been used to degrade phenol at initial concentrations of up to 2 g/L in less than two days.
- a sieve-like container within a fermenter held the immobilized cells in order to simulate entrapped microorganisms in a packed column. It was found that immobilization acts as a protective cover against phenol toxicity.
- Sofer has studied an activated sludge of a mixed microbial population immobilized in calcium alginate gel for biodegradation of chlorophenol. Sofer was able to obtain a physically strong bead structure by optimizing the concentrations of sodium alginate and calcium chloride. The immobilized cells in Sofer's study showed the ability to degrade chlorophenol in various concentrations (up to 100 ppm).
- the method developed by Hashimoto and Furukawa does not produce PVA beads which are long lasting and which can withstand the stress and pressures presented when the PVA beads formed by the method of Hashimoto and Furukawa are formed into a permeable barrier.
- the Hashimoto and Furukawa method beads fracture and compress under the pressure and generally will dissolve in less than thirty (30) days.
- the PVA-boric acid method is inexpensive compared to other methods and allows operation of an immobilized cell system at 2-3 times the contaminate loading rate of conventional systems. Since activated sludge cells become surrounded by extracellular polymer, microbial activity is not reduced during the immobilization process where the pH was 4.0 for 24 hours.
- Wu and Wisecarver have prepared PVA beads using a modification of the PVA- boric acid method but added a small amount of sodium alginate to prevent or minimize the tendency for the beads to agglomerate.
- the viability of Pseudomonas immobilized cells was demonstrated by utilizing them in a fluidized bed bioreactor for a period of two weeks. The beads were able to withstand high shears with no sign of breakage when an 8-L fluidized bed column was sparged at an air flow rate of 1.4 L/min.
- Kindzierski investigated the use of activated carbon and two other synthetic ion- exchange resins as support materials for an anaerobic phenol-degrading microorganisms. Rapid adsorption of phenol on activated carbon without bacteria occurred over the first 33 minutes. The adsorption of phenol on activated carbon with bacteria was 3.9 times smaller than on activated carbon without bacteria. Kindzierski demonstrated that activated carbon exhibited favorable qualities as a biological support for the rapid development of attached biomass. Also, a substantial decrease in the rate of phenol adsorption by activated carbon due to the colonization of the bacteria was observed.
- Ehrhardt and Rehm studied the adsorption of phenol as well as Pseudomonas sp. and Candida sp. on activated carbon, and the phenol degradation by these immobilized microorganisms was compared to that of free microorganisms. They observed that one gram of activated carbon adsorbed 4x10E9 Pseudomonas cells and 3x10E8 Candida cells in about 10 hours. Results of the degradation studies showed that free cells did not tolerate more than 1.5 g/L phenol, while the immobilized microorganisms survived at temporary 2.0 hour of high phenol concentrations up to 15 g/L, and they ultimately degraded about 90% of the adsorbed phenol.
- the polymeric materials tested included cellulose triacetate (mono-carrier), polyacrylamide, K-carrageenan and a combination of cellulose triacetate and calcium alginate (bi-carrier).
- the mono-carrier was used to determine long term operational performance because it had better mechanical strength.
- the bi-carrier was more porous and more elastic than the mono-carrier. It was determined that K-carrageenan and calcium alginate were weak in mechanical strength.
- activated carbon allows storage of substances that are difficult to biodegrade. Such storage provides a longer contact time between the microbial population and the substrates and could promote microbial acclimation and subsequent biodegradation.
- the invention has advantages over the prior art in that, (1) it can reduce organic contaminants into harmless by-products by using immobilized cells; (2) it has demonstrated continuous high stability and control under many different operating conditions than previous methods; (3) it provides a very cost effective process for treatment of contaminated groundwater; (4) it has demonstrated high tolerance against environmental stresses.
- the present invention solves or substantially reduces in critical importance problems in the prior art by providing a biological processes that uses immobilized cells system to treat contaminated groundwater efficiently and cost-effectively.
- immobilized cells can limit the movement of microorganisms and protect them against environmental stresses.
- the present invention encompasses a method of providing a biological permeable barrier comprising a permeable barrier of encapsulated microorganisms having an affinity for a contaminate that is polluting a water supply.
- the invention provides decontamination of a water supply, such as a groundwater, by allowing the groundwater to flow through the biological permeable barrier comprising an encapsulated microorganism so that the microorganism selected for use in the permeable barrier can biodegrade the contaminate. During the biodegradation the microorganism converts the contaminate into a less harmful or non-harmful moiety.
- This invention entails immobilizing microbial organisms which are acclimated to the target contaminants in unique immobilized systems.
- Immobilization is key to the ability of this process to concentrate a large active bacteria mass for treatment of contaminated water. This superior ability to concentrate active bacterial mass in the barrier offers considerable benefits to the performance of the barrier. Entrapped or encapsulated cells are shielded from their surroundings while the target pollutants still can flow into the supports and be metabolized there. Immobilization can be a form of biocontainment since it provides a way to control the spreading of recombinant cells in the environment. Additionally, the immobilization of high cell densities in compact reactors results in enhanced biodegradation rates when compared to conventional systems. Since such a system is much less dependent on the growth rates of the microorganisms involved, short retention times can be applied and thus high removal rates attained.
- the present invention is demonstrated by immobilizing microorganisms on example carrier materials or matrices.
- a carrier material to produce PVA-immobilized cells.
- a second example of a suitable carrier material is Granular Activated Carbon (GAC) which is used to provide GAC-immobilized cells.
- GAC Granular Activated Carbon
- the present invention thereby fulfills the following objectives: providing a biological permeable barrier media comprising a carrier material and a microorganism suitable to biotransformation of a contaminate in groundwater; providing a biological permeable barrier media which is easy to operate and lower in cost than previously used methods of treating contaminated groundwater.
- biodegradation of 2,4,6 trichlorophenol is demonstrated using polyvinyl alcohol (PVA)-immobilized cells and granular activated carbon (GAC)-immobilized cells as biological permeable barrier media.
- PVA polyvinyl alcohol
- GAC granular activated carbon
- the method involves the entrapment of active microorganisms into a media that would provide controlled environment for their attachment and growth.
- a further object of the invention is to provide a very stable and efficient process to treat contaminated groundwater by using immobilized cells without formation of any harmful by-products.
- Fig. 1 is a schematic representation of a biological permeable barrier placed to intercept underground water for treatment by immobilized cells.
- Fig. 2 is a schematic representation of a small biological permeable barrier (column) placed above ground for treatment of contaminated groundwater
- Fig. 3 is a graph showing TCP removal by PVA on Column 1.
- Fig. 4 is a graph showing TCP removal by PVA on Column 2.
- Fig. 5 is a graph showing TCP removal by GAC on Column 3.
- Fig. 6 is a graph showing TCP removal by GAC on Column 4.
- Fig. 7 is a graph showing dissolved oxygen uptake by PVA on Column 1.
- Fig. 8 is a graph showing dissolved oxygen uptake by PVA on Column 2.
- Fig. 9 is a graph showing dissolved oxygen uptake by GAC on Column 3.
- Fig. 10 is a graph showing dissolved oxygen uptake by GAC on Column 4.
- Fig. 11 is a graph showing a comparison of the percent removal of TCP by PVA Column 1 , as measured and calculated from gas chromatograph.
- Fig. 12 is a graph showing percent TCP removal by PVA on Column 2, as measured and calculated from gas chromatograph results.
- Fig. 13 is a graph showing a comparison of percent TCP removal by GAC
- Fig. 14 is a graph showing percent TCP removal by GAC Column 4, as measured and calculated from gas chromatograph results.
- Fig. 15 is a graph showing pH drop by PVA on Column 1.
- Fig. 16 is a graph showing pH drop by PVA on Column 2.
- Fig. 17 is a graph showing pH drop by GAC on Column 3.
- Fig. 18 is a graph showing pH drop by GAC on Column 4.
- Fig. 19 is a graph showing TCP concentrations on PVA Column 2 in response to the high shock loads of TCP.
- Fig. 20 is a graph showing dissolved oxygen changes during high shock loads on PVA Column #2.
- Fig. 21 is a graph showing chloride release changes during high shock loads on
- Fig. 22 is a graph showing pH changes during high shock loads on PVA Column 2.
- Fig. 23 is a graph showing TCP concentrations in response to high shock loads on GAC Column #4.
- Fig. 24 is a graph showing dissolved oxygen changes on GAC Column #4 during high shock loads.
- Fig. 25 is a graph showing chloride release changes during high shock loads on GAC Column #4.
- Fig. 26 is a graph showing pH changes during the high shock loads on GAC Columns.
- Fig. 27 is a graph showing effluent TCP concentrations as a response to low dissolved oxygen.
- Fig. 28 is a graph showing dissolved oxygen uptake responses to influent dissolved oxygen interruptions.
- Fig. 29 is a graph showing chloride releases during and after influent dissolved oxygen upsets on PVA Column #1.
- Fig. 30 is a graph showing effluent pH changes during and after influent dissolved oxygen upsets on PVA Column #1.
- Fig. 31 is a graph showing TCP concentrations in response to low dissolved oxygen on GAC Column #3.
- Fig. 32 is a graph showing dissolved oxygen uptake responses to influent dissolved oxygen interruptions on GAC Column #3.
- Fig. 33 is a graph showing chloride releases during and after influent dissolved oxygen upsets on GAC Column #3.
- Fig. 34 is a graph showing effluent pH changes during and after influent dissolved oxygen upsets on GAC Column #3.
- Fig. 35 is a scanning electron micrograph showing biofilm formation inside of a PVA bead at nine months.
- Fig. 36 is a scanning electron micrograph showing microcolonies inside PVA beads at nine months.
- Fig. 37 is a scanning electron micrograph showing immobilized cells on GAC at
- Fig. 38 is a scanning electron micrograph showing bacteria colonization on GAC.
- Fig. 39 is a gas chromatograph with attached mass spectrometer analysis of the column influent.
- Fig. 40 is a gas chromatograph with mass spectrometer attached analysis of the effluent of PVA Column #1.
- Fig. 41 is a gas chromatograph with mass spectrometer attached analysis of the effluent of Column #2.
- Fig. 42 is a gas chromatograph with mass spectrometer attached analysis of the effluent of GAC Column #3.
- Fig. 43 is a gas chromatograph and mass spectrometer analysis of the effluent of GAC Column #4.
- the present invention comprises a biological permeable barrier comprising a microorganism that is immobilized on a carrier material, or matrix, to provide biotransformation of a contaminate molecule or substance contained in groundwater.
- the groundwater can be treated with the permeable barrier in-situ or it can be treated by removal of the groundwater from the ground and allowing the groundwater to flow across the biological permeable barrier of the invention.
- the groundwater is allowed to flow across the biological permeable barrier of the invention by excavating a hole or trench in the ground to intercept the direction of flow of the groundwater and filling the hole or trench with the biological permeable barrier having a microorganism immobilized thereon which is capable of biotransformation of the contaminate in the groundwater.
- the microorganism is immobilized on a solid or semi-sold carrier material or matrix which provides structure and stability to the microorganism colonies.
- the carrier material or matrix can be of any suitable material which provides a surface to which the microorganism colonies can attach and grow.
- the carrier material or matrix need not provide any nutrients for the microorganism.
- suitable carrier materials provide a convolute structure having clefts or holes or tunnel spaces in which the microorganism can take hold and be somewhat protected from exposure to the contaminate. In this manner the microorganism can tolerate contact with much higher concentrations of the contaminate than would be possible when the microorganism is directly presented with the contaminate.
- a further feature of the carrier material is that it also provides a physically resilient structure for the microorganism and allows the cell colony to be placed in a trench or a test column for experiments without causing compression and damage to the microorganism colonies.
- Two embodiments of the biological permeable barrier were prepared and used to demonstrate the effectiveness of the barrier on a contaminate.
- the contaminate selected for these examples of the invention was 2,4,6 trichlorophenol (TCP).
- TCP 2,4,6 trichlorophenol
- the aerobic degradation of pathway involves the dehogenation or degradation of TCP to dichlorophenol to 4-chlorophenol, which in turn produces 1 ,2,4-benzenetriol, and finally a mixture of polyquinoid acids.
- a microorganism was selected which had received previous exposure to higher than normal environmental concentrations of TCP and the microorganism was immobilized on two different carrier media: a polyvinyl alcohol bead (PVA beads); and granulated activated carbon (GAC).
- PVA beads polyvinyl alcohol bead
- GAC granulated activated carbon
- Activated sludge containing microorganisms was obtained from the Georgia- Pacific Leaf River Pulp Mill, New Augusta, Mississippi.
- the activated sludge was obtained from the recirculation line where there is a high cell concentration.
- the mill operation included a bleaching process which would unintentionally produce some chlorophenols.
- the microorganisms from this mill were assumed to have had some exposure to chlorophenols which would allow quicker acclimation for the purpose of this project.
- the microorganisms were further acclimated by feeding them TCP (10 mg/L) as their sole carbon source with continuous aeration and additional nutrients consisting of a phosphate buffer solution, a magnesium sulfate solution, a calcium chloride solution, and a ferric chloride solution.
- TCP 10 mg/L
- additional nutrients consisting of a phosphate buffer solution, a magnesium sulfate solution, a calcium chloride solution, and a ferric chloride solution.
- the carbon source for microorganisms is TCP.
- the activated sludge was centrifuged using an international Equipment Co. Clinical Centrifuge for 10 minutes at 4000 rpm to obtain biomass for immobilization into polyvinyl alcohol and granular activated carbon.
- Distilled water was added to 43.7 g of PVA to obtain a 330 mL solution.
- the solution was heated to 60 degree C while stirring constantly until the PVA was dissolved.
- a 3.5 mL volume of a 1 -3% sodium alginate solution was added to the PVA solution.
- the PVA-sodium alginate solution was cooled to 35 degree C.
- the centrifuged cells (43.7 g wet weight) and 10 mLs distilled water mixed with 1.3 mLs of nutrient medium were added to the cooled PVA-sodium alginate solution and stirred thoroughly.
- the solution was then drawn through tygon tubing (ID 3.1 mm) by a peristaltic pump (Cole- Parmer 7553-30) and extruded through a tubing connector with a 1.0 mm diameter opening inserted into the end of the tubing. As droplets formed, they fell into a gently stirred boric acid solution to form beads. The beads were cured in the gently stirred boric acid solution for 24 hours. The beads were then rinsed and soaked thoroughly in distilled water several times to remove all of the boric acid solution from the beads.
- the PVA beads were prepared using this method produced porous, rubber-like, elastic beads for the purpose of immobilizing cells and using them as a biological permeable barrier medium. A bed of beads was characterized with its density, porosity, permeability, and compressibility or deformation.
- GAC was washed with distilled water several times and dried completely in 103° C oven before use.
- the amount of biomass used for immobilization on both permeable barriers (GAC and PVA beads) was 43.7 grams for short columns and 86.0 grams for the long columns.
- the amounts of GAC for short and long column were 21.0 and 10.5 grams, respectively, for the 3% mixture of GAC/sand.
- the biomass and GAC were then agitated vigorously in 100 mLs distilled water for 24 hours.
- the GAC that settled by gravity was mixed with sand and used in column studies (3% GAC /sand mixture).
- Silica sand was washed with distilled water and oven dried at 103°C separately. The two materials were then blended to achieve the desired weight ratio.
- the present invention proposes a method of use of PVA-immobilized cells and 3%GAC- immobilized cells/sand mixture as two novel candidates for biological permeable barrier media to biodegrade contaminated groundwater.
- Table 3 Summarizes the eight different operating conditions to simulate biodegradation of TCP contaminated groundwater using PAV and GAC immobilized cells as biological permeable barriers.
- a total of four acrylic columns were set up as aerobic, continuous flow packed-bed reactors.
- Columns #1 and #2 consisted of 10 and 20-cm beds of PVA -immobilized cells beads (3-5 mm)
- Columns #3 and #4 consisted of 10 and 20-cm beds of 3% GAC immobilized cells and 97% clean silica sand. These columns had an inside diameter of 5.0 cm.
- a 5.0 cm diameter 200-sieve mesh copper screen was placed at the top and bottom of each of the columns.
- the groundwater was spiked with TCP to provide the various TCP concentrations used during these studies and was prepared in 25.0 liter bottles and covered to prevent photolytic degradation.
- Nutrient solutions were added to the TCP- spiked groundwater: phosphate buffer solution; magnesium sulfate solution; calcium chloride solution; and ferric chloride solution.
- a peristaltic pump (Cole-Parmer 7553-30) with four heads (Model 7013) and tygon tubing was used to pump the groundwater into the base of the columns (upflow mode).
- a schematic diagram of the columns used in the study is shown in FIG. 2.
- the effects of external disturbances such as a high shock load and low dissolved oxygen (DO) were evaluated on PVA and GAC immobilized cells systems.
- DO dissolved oxygen
- PVA columns #1 and #2 reduced the influent TCP concentration to zero on day 17 and 13, respectively.
- PVA column #2 with a 20.0-cm bed height provides longer contact time between cells and TCP than PVA column #1 with a 10.0-cm bed height. Both PVA columns maintained 100% TCP removal for remaining time of this experiment.
- the Cl " concentrations in the effluents of all four columns showed an increase of about 6.0 to 8.0 mg/L.
- the increase in chloride concentration supports aerobic dehalogenation of TCP.
- 0.54 mg of chloride is expected to be release based on stiochiometry.
- Aerobic dehalogenation of TCP produced HCl which would cause the drop in effluent pH.
- the influent feed solution had a pH range from 8.1 - 8.3.
- the approximate average pH in the effluents from columns #1 , #2, #3, and #4 are 7.7, 7.7, 7.9, and 7.6, respectively.
- the estimated amounts of CI " concentration in the effluents of columns #1 , #2, #3, and #4 needed to cause the observed drops in pH are 10.6, 10.6, 7.1 , and 12.4 mg/L, respectively.
- the Cl- concentrations obtained from the pH curve are (15-35 %) higher than CI"concentrations measured which ranged from 6.0 -8.0 mg/L chloride.
- the possible explanation could be the formation of acids other than HCl.
- the drop in pH supports the dehalogenation of TCP and formation of HCl.
- Both PVA columns were able to remove TCP from the influent for up to a week.
- TCP was detected in the effluent of both PVA columns.
- the effluent TCP concentration in column #1 was 1.2 mg/L on day 40.
- the TCP effluent concentration in column #1 continued to rise and reached 6.5 mg/L on day 58.
- the TCP effluent concentration in column #2 also started to rise on day 40 and reached its maximum concentration of 4.9 mg/L on day 58.
- the removal efficiencies of column #1 and #2 reduced from 100% to 68.0 % and 76.0 %, respectively.
- the explanation for this occurrence during this period is that the dissolved oxygen (DO) was insufficient for complete biodegradation of 20.0 mg/L of TCP.
- the effluents of PVA columns #1 and #2 have an average effluent DO of 2.9 ⁇ 0.5 mg/L and 3.1 ⁇ 0.4 mg/L, respectively. This was a clear indication of biological activity occurring in both PVA columns.
- the cells in PVA columns #1 and #2 were able to consume about 66% and 64% of the average 8.6 mg/L DO in the influent, respectively.
- the average DO provided for this experiment is about 50% less than the DO needed for aerobic mineralization of 20.0 mg/L TCP.
- the effluents of GAC columns #3 and #4 had an average DO of 3.0 mg/L and 3.1 mg/L, respectively.
- the cells in GAC columns #3 and #4 were also able to consume about 66% and 64%, respectively, of the average 8.6 mg/L DO in the influent.
- the drop in pH for the first 11 days was greater than for the last 14 days for all four columns.
- the approximate average effluent pH for the first 11 days of the experiment for columns #1 , #2, #3, and #4 were 7.6, 7.4, 7.7, and 7.6, respectively.
- the effluent pHs for all four columns were 8.1.
- the drop in pH tends to support the concept of dehalogenation of TCP and formation of HCl in the effluents.
- the smaller drop in pHs of all four columns from day 11 to day 58 correlates well with the smaller chloride release measured possibly due to insufficient DO for complete mineralization of 20.0 mg/L TCP.
- Average chloride releases in the PVA columns #1 , #2 and GAC columns #3, #4 were 9.19 ⁇ 2.11 , 10.25 ⁇ 1.97 and 10.73 ⁇ 2.5, 11.1 ⁇ 1.8 mg/L, respectively.
- the measured chloride concentration in both PVA and GAC columns effluents were very close in value to the theoretical chloride release expected for dehalogenation of 20.0 mg/L of TCP.
- the C:N:P nutrient ratio used in the first three column studies was 100:18:188.
- the standard ratio for C:N:P for microorganisms to grow is 100:10:3. In order to avoid unnecessary addition of nutrients, the C:N:P ratio was adjusted from 100:18:188 to
- the influent feed solution had an approximate average pH of 7.9.
- the approximate average of the effluent pH for both PVA columns #1 and #2 was 7.5.
- the approximate average of the effluent pH for both GAC columns #3 and #4 was 7.6.
- the drop in pH from 7.9 to 7.5 shows that a 2.9 mL volume of 0.1 N HCl would be required. This is a 10.3 mg/L chloride concentration (2.9 mL/L X
- the removal efficiency of all four columns was evaluated as TCP concentration increased to 30.0 mg/L.
- the flow rate for all columns remained at 1 mL/min.
- the applied loading for the columns (#1 , #3) and (#2, #4) were 0.22 g L "1 d _ and 0.11 g L "1 d "1 , respectively.
- the influent feed solution was aerated with pure oxygen for 10.0 -
- the immobilized cells in all four columns were able to use DO efficiently and removed 30.0 mg/L of TCP during the entire course of this experiment.
- Average chloride concentrations in the effluent for columns #1 ,#2,#3, and #4 were 15.7 ⁇ 4.5, 17.1 ⁇ 4.9, 18.1 ⁇ 3.3, and 18.9 ⁇ 3.2 mg/L, respectively. Aerobic dehalogenation of 30.0 mg/L of TCP should release 16.2 mg/L chloride.
- the measured values for all four columns are close to theoretical chloride release for 30.0 mg/L TCP.
- the influent feed solution had approximate average pH of 8.0.
- the approximate average effluent pH for both PVA column #1 , #2 was 7.2.
- An approximate average effluent pH for both GAC columns #3 and #4 was 7.3.
- the drop in pH from 8.0 to 7.2, and 7.3 show that 5.0 mL and 4.0 mL volume of 0.1 N HCl would be required.
- both GAC columns #3 and #4 were expected to release 14.2 mg/L chloride (4.0 mL/L X3.55 mg/mL).
- the drop in pH supports inorganic chloride release which resulted from dehalogenation of TCP and formation of HCl.
- the influent feed solution had an average pH of 7.9.
- the approximate average effluent pH for PVA column #1 during the transition period (days 113-119) was 7.5.
- a drop in pH from 7.9 to 7.5 shows that 2.0 mL volume of 0.1 N HCl would be required. This is a 7.1 mg/L chloride concentration (2.0 mL/L X 3.55 mg/mL). This was expected due to partial TCP removal and high DO reading during the transition period.
- An approximate average pH value for columns #2, #3, and #4 was 7.3. This equals 10.7 mg/L of chloride (3.0 ml_/L X 3.55 mg/mL) which is similar to the theoretical chloride concentration of 10.8 mg/L expected from the dehalogenation of 20.0 mg/L TCP.
- the drop in pHs supports the concept of dehalogenation of TCP and release of chloride (HCl).
- the removal efficiency of all four columns where the TCP concentration was increased to 40.0 mg/L was examined.
- the flow rate for all columns remained at 4 mL/min.
- the applied loading for columns (#1 , #3) and columns (#2, #4) was 1.2 and 0.6 g L- 1 d _1 , respectively.
- the influent feed bottle was aerated with pure oxygen for 10.0 -15.0 minutes every day to maintain DO of around 27.0 mg/L.
- the influent bottle was completely capped to prevent the loss of oxygen.
- the average influent feed TCP concentration was 40.6 ⁇ 0.71 mg/L.
- An average effluent TCP concentration for PVA columns #1 and #2 was 15.5 ⁇ 3.6 and 8.9 ⁇ 1.2 mg/L, respectively.
- the change of influent TCP concentration had an impact on both PVA columns in terms of TCP removal efficiency.
- the overall removal efficiency of PVA columns # 1 and # 2 was decreased to 61% and 80%, respectively.
- TCP removal by PVA column #1 improved over the course of this experiment.
- TCP removal efficiency for PVA column #1 over the first week was 54% and increased to 67% during the last 10 days of the experiment.
- PVA column #2 had a removal efficiency of 76% in the first week which was increased to 81 % during the last 10 days of the experiment.
- Dissolved oxygen provided was around 27.8 mg/L, which are about 22 % less than DO needed. This may have had an impact on the PVA columns removal efficiency of 40.0 mg/L TCP.
- the average inorganic chloride release for columns #1 , #2, #3, and #4 was 12.5 ⁇
- the influent feed solution had an approximate average pH 8.2.
- An approximate average pH for PVA columns #1 and #2 was 7.0 and 6.9, respectively.
- An approximate average pH for the GAC columns #3 and #4 was 6.7 and 6.9, respectively.
- the drop in pH from 8.2 to 7.0, 6.9, 6.7 shows that an 8.0, 8.0, and 11.0 mL volume of 0.1 N HCl would be required, respectively to account for such a pH change.
- the expected chloride concentration in columns #1 , #2, #3, and #4 should have been 28.4, 28.4, 28.4, and 42.6 mg/L, respectively, which is about 24 - 50 % higher than the theoretical chloride release.
- the anaerobic activity might be present as localized pockets (since DO in the effluent was between 4 and 9 mg/L) in the columns which would also cause the release of acids.
- the release of acids should show up in effluent pH value.
- the dissolved oxygen consumption of the PVA columns decreased on day 113 due to flow rate increase and partial TCP removal.
- the oxygen consumption of both PVA columns and GAC columns decreased by increasing applied loading during periods 6-8 (column study 6-8).
- the impact of high loading on the PVA column #1 was greater than the PVA column #2.
- the decrease in oxygen consumption of both GAC columns (#3 and #4) during periods 6-8 (column study 6-8) had no impact on their elimination capacities.
- the consumption of dissolved oxygen by the columns is clear indication of biological activity under aerobic conditions. The results are presented in Figs. 7, 8, 9, and 10.
- the PVA (long) column #2 and GAC (long) column #4 were subjected twice (at two different times) to a high concentration (> 550 mg/L) of TCP for 50.0 hr. During this 50.0 hr period, the PVA (short) column #1 and GAC (short) column #3 were subjected to low DO ( ⁇ 2.0 mg/L) conditions. This external disturbance study lasted 74 days.
- the TCP influent feed concentration was around 40.0 mg/L. With a flow rate of 2 mL/min, this resulted in the TCP loading of 0.3 g L -1d -1 for both PVA and GAC immobilized columns.
- the feed bottle was oxygenated by bottled pure oxygen everyday (during 74 days) for at least 15 minutes.
- the influent bottle was capped to prevent oxygen loss.
- TCP concentration in the effluent of PVA column #2 increased and decreased in the same pattern as in the first shock load. This time, the recovery time was much shorter.
- the recovery time of the PVA column #2 from the second shock load was about 5 days.
- TCP influent-effluent
- the mass balance on TCP (influent-effluent) during the second shock load indicate that the cells were active and biodegrade 169 mg of TCP which is about 15% of total 1154 mg of influent TCP.
- the cells in the PVA column remained active indicated by DO uptake, chloride release, and pH drop in the effluent during the second shock load.
- the results also indicate that the process recovered within 5 days as seen by 100% removal of TCP in the effluent. Simultaneous oxygen uptake, chloride releases, and pH drop of the effluent shown in Figs. 20, 21 and 22. gave further support to the occurrence of TCP biodegradation by PVA column #2.
- the effluent average pH drop from 8.1 to 6.6 would have required a 23 mL volume of 0.1 N HCl to have the same pH drop. This is 60.4 mg/L Cl" concentration which was close to the chloride measured (57 mg/L) during this period.
- the pH drop in the effluent along with chloride release (measured) supports complete dehalogenation of TCP.
- Aerobic mineralization of 40.0 mg/L TCP requires at least 35.6 mg/L of DO to release
- the immobilized cells in GAC column #4 continued to biodegrade already adsorbed TCP until day 213.
- the samples taken on day 217 indicated that there was no extra chloride release in the effluent which was consistent with rise of the effluent pH. Therefore, the cells remained active and survived the shock load and continued bioregenerate the carbon completely during 19 days under DO deficiency (anaerobic condition).
- the GAC column #4 adsorbed a total of 3120 mg TCP out of 3237 mg TCP applied in the influent.
- the immobilized cells remained very active during the second shock load and continued to dehalogenate TCP.
- the cells were able to biodegrade (aerobic condition) approximately 32.0 mg/L of TCP with the corresponding DO usage, chloride release, and effluent pH drop.
- the immobilized cells started to biodegrade TCP already adsorbed on GAC column during the second shock load.
- the extra chloride released by GAC column and the effluent pH drop during 233-240 followed the same pattern as seen during days 194-213.
- the immobilized cells in GAC column #4 remained active during the second shock load and continued to biodegrade TCP under both aerobic and anaerobic conditions.
- immobilized cells in PVA column #1 recovered within 11 days and reduced TCP concentration by 90% with corresponding DO consumption, chloride release and pH drop in the effluent as shown in Figs. 28, 29 and 30. These results demonstrated the sensitivity of immobilized cells in PVA column and, at same time, the tolerance of the immobilized cells toward the low DO influent.
- the GAC column also reacted to the interruption of DO.
- the influent TCP continued to be biodegraded despite the deficiency of dissolved oxygen as indicated by chloride release, effluent pH drop, and 100% TCP removed as shown in Fig. 31.
- Both anaerobic activity and adsorption were responsible for the removal of influent TCP during the deficiency of DO as indicated by chloride release and pH drop of the effluent.
- the results support the partial removal of TCP by anaerobic bacteria.
- the amount of chloride release and pH drop in the effluent correspond with only 40% of influent TCP dehalogenated by anaerobic bacteria (insufficient DO).
- Adsorption and anaerobic dehalogenation were responsible for 100% removal of TCP on days 224 and 225. It is theorized that anaerobic dehalogenation of some TCP resulted in the effluent chloride release and pH drop during the second DO interruption. These results demonstrated the sensitivity of aerobic immobilized cells and, at the same time, the tolerances of these cells toward low DO.
- the PVA-immobilized cells were unable to degrade TCP during oxygen upset. In both cases of DO interruption, increases and recoveries of effluent TCP concentrations followed the same pattern. The second time recovery times were shorter.
- the GAC column #3 offered both adsorption and anaerobic biodegradation during the interruptions of DO.
- the adsorption capacity of GAC offered 100% removal of TCP.
- the TCP adsorbed onto carbon subsequently was released and consumed by bacteria (bioregeneration).
- Insufficient DO promoted the activity of anaerobic bacteria which resulted to biodegradation of TCP, release of chloride, and drop of pH. Since anaerobic bacteria are slower growers they could not grow to a significant enough number in 50 hrs to do any good for TCP removal so then either they are present in the column all the time or some of the degraders may be facultative.
- the GAC immobilized cells resumed their activity and continued to biodegrade TCP.
- GAC-immobilized cells responses to insufficient DO are shown in Figs. 31 , 32, 33 and 34.
- Jarvinen et al. (1994) concluded that aerobic chlorophenol biodegradation does not result in partially dechlorinated metabolites. They claim mineralization of chlorophenols (CP) since all CP removals were confirmed by chloride release and no chlorinated intermediates were found. Makinin et al. (1993) concluded that the chloride release and H+ generation (pH decrease) is an indication of chlorophenol mineralization. The results of this research can be directly compared to the above studies. The results of GC/MS confirm that no chlorinated intermediates or phenol was found in the PVA and GAC columns effluent.
- PVA-immobilized cells Biological permeable barriers using PVA-immobilized cells and 3% GAC- immobilized cells are able to biodegrade contaminates, of which TCP is merely one, from groundwater under various operational conditions.
- the immobilized cells are protected against toxic shock loads of contaminates by the PVA and GAC.
- PVA- immobilized cells system is a successful media for use in a trench-based permeable barrier to remove contaminates.
- PVA-immobilized cells can tolerate low DO and recovered (100% efficiency) within 11 -21 days.
- PVA-immobilized cells and 3% GAC-immobilized cells demonstrate the following advantages of PVA-immobilized cells and 3% GAC-immobilized cells as biological permeable barriers.
- PVA-immobilized cells and 3% GAC-immobilized cells are two successful media for use in a trench-based permeable barrier to remove TCP and/or other contaminates from groundwater either in-situ or ex-situ.
- PVA-immobilized cells provided up to 100% removal efficiency for TCP loading up to 300 mg/liter per day and GAC-immobilized cells provided 100% removal efficiency for TCP loading up to 1200 mg/liter per day.
- Microorganisms were protected against high shock loads by immobilization on PVA beads and recovered to steady state conversion within 11 -21 days. PVA- immobilized cells tolerated deficiency of dissolved oxygen and regained their activity once they received adequate DO.
- GAC maintained substantial adsorption capacity even with development of bacterial growth.
- the survival of the immobilized cells in spite of the addition of a shock load was the result of rapid adsorption of the contaminate by GAC.
- Bioregeneration occurred as the adsorbed contaminate was desorbed and metabolized by immobilized cells. Bioregeneration was shown by the extra chloride release, with corresponding pH drop in the effluent, after adsorption capacity of GAC was exhausted by a high shock load of contaminate.
- PVA-immobilized cells were unable to offer any of the adsorption advantages provided by GAC-immobilized cells.
- Stability, control, detoxification of contaminants, and high performance shown by both PVA-immobilized and GAC-immobilized cells systems under variety of operating conditions represent biological permeable barrier systems that eliminate the need to excavate and replace the media from trench reclamation sites which represents a substantial improvement over the prior art barriers.
- FIGS. 35 and 36 are scanning electron micrographs of the beads after 240 days showing mirocolonies formed inside the PVA beads.
- Figures 37 and 38 are scanning electron micrographs of GAC-immobilized cells showing microcolonies of the cells on inner surfaces of GAC.
- PVA-immobilized cells remained permeable and structurally sound over time (240 days). PVA-immobilized cells tolerated high shock load, low DO and resumed its biological activity to a steady state in a matter of a few days. PVA-immobilized cells remained 100-91% efficient at applied loadings of 300 mg L _1 .d “1 and 600 " , respectively.
- TCP selected contaminate
- PVA-immobilized cells completely dehalogenated TCP without formation of chlorinated intermediates or phenol. The lack of chloride intermediates or phenols is demonstrated in Figs. 39, 40, 41 , 42 and 43 which are gas chromatograph/mass spectra readouts of PVA column effluents.
- GAC-immobilized cells offered 100% removal of TCP by a combination of biological degradation and physical adsorption.
- the cells functioned as biological processors and the GAC functioned as a support and adsorbent barrier.
- GAC- immobilization protected cells from high shock loads by rapid TCP adsorption.
- the use of PVA-immobilized cells and 3% GAC-immobilized cells/sand as two biological permeable barrier media to remove contaminates from groundwater is an important improvement over the prior art methods and provides important operational benefits such as no precipitation of solid contaminates, no need to replace the barrier, no need to remove the barrier once it has been in operation due to collection of contaminates, no by-product contaminates are produced, complete detoxification of the contaminate can be obtained, low operation cost and maintenance cost of the barrier is presented, no sludge is produced which must be removed from the site and destroyed and no hazardous waste is produced.
Landscapes
- Engineering & Computer Science (AREA)
- Life Sciences & Earth Sciences (AREA)
- Soil Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- Health & Medical Sciences (AREA)
- Water Supply & Treatment (AREA)
- Hydrology & Water Resources (AREA)
- Biomedical Technology (AREA)
- Biotechnology (AREA)
- General Health & Medical Sciences (AREA)
- Microbiology (AREA)
- Molecular Biology (AREA)
- Mycology (AREA)
- Biological Treatment Of Waste Water (AREA)
- Purification Treatments By Anaerobic Or Anaerobic And Aerobic Bacteria Or Animals (AREA)
Abstract
Description
Claims
Applications Claiming Priority (3)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
US432090 | 1999-11-01 | ||
US09/432,090 US6809774B1 (en) | 1998-11-06 | 1999-11-02 | Wrist-carried camera and watch-type information equipment |
PCT/US2000/030006 WO2001032566A1 (en) | 1999-11-02 | 2000-10-31 | Biological permeable barrier to treat contaminated groundwater using immobilized cells |
Publications (2)
Publication Number | Publication Date |
---|---|
EP1144315A1 true EP1144315A1 (en) | 2001-10-17 |
EP1144315A4 EP1144315A4 (en) | 2003-03-26 |
Family
ID=23714736
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP00978309A Ceased EP1144315A4 (en) | 1999-11-02 | 2000-10-31 | Biological permeable barrier to treat contaminated groundwater using immobilized cells |
Country Status (3)
Country | Link |
---|---|
EP (1) | EP1144315A4 (en) |
CA (1) | CA2372253C (en) |
WO (1) | WO2001032566A1 (en) |
Families Citing this family (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
CN111440786A (en) * | 2020-03-31 | 2020-07-24 | 青岛农业大学 | Method for removing soil 2,4, 6-trichlorophenol by biomass charcoal immobilized high-efficiency degrading strain |
Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5290693A (en) * | 1992-07-08 | 1994-03-01 | National Science Council | Immobilization of microorganisms or enzymes in polyvinyl alcohol beads |
EP0692319A1 (en) * | 1994-07-15 | 1996-01-17 | Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno | Method and device for cleansing chemically polluted ground |
US5626437A (en) * | 1994-07-11 | 1997-05-06 | Foremost Solutions Inc. | Method for in-situ bioremediation of contaminated ground water |
Family Cites Families (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5057227A (en) * | 1990-10-09 | 1991-10-15 | University Of South Carolina | Method for in-situ removal of hydrocarbon contaminants from groundwater |
-
2000
- 2000-10-31 WO PCT/US2000/030006 patent/WO2001032566A1/en active Application Filing
- 2000-10-31 EP EP00978309A patent/EP1144315A4/en not_active Ceased
- 2000-10-31 CA CA002372253A patent/CA2372253C/en not_active Expired - Fee Related
Patent Citations (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US5290693A (en) * | 1992-07-08 | 1994-03-01 | National Science Council | Immobilization of microorganisms or enzymes in polyvinyl alcohol beads |
US5626437A (en) * | 1994-07-11 | 1997-05-06 | Foremost Solutions Inc. | Method for in-situ bioremediation of contaminated ground water |
EP0692319A1 (en) * | 1994-07-15 | 1996-01-17 | Nederlandse Organisatie Voor Toegepast-Natuurwetenschappelijk Onderzoek Tno | Method and device for cleansing chemically polluted ground |
Non-Patent Citations (1)
Title |
---|
See also references of WO0132566A1 * |
Also Published As
Publication number | Publication date |
---|---|
WO2001032566A1 (en) | 2001-05-10 |
CA2372253C (en) | 2008-06-17 |
EP1144315A4 (en) | 2003-03-26 |
CA2372253A1 (en) | 2001-05-10 |
WO2001032566A8 (en) | 2002-04-11 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
US6337019B1 (en) | Biological permeable barrier to treat contaminated groundwater using immobilized cells | |
US6214607B1 (en) | Method and apparatus for treating perchlorate-contaminated drinking water | |
US6331300B1 (en) | Compositions for providing a chemical to a microorganism | |
Gingras et al. | Biological reduction of perchlorate in ion exchange regenerant solutions containing high salinity and ammonium levels | |
Zilouei et al. | Biological degradation of chlorophenols in packed-bed bioreactors using mixed bacterial consortia | |
Shin et al. | Removal of polychlorinated phenols in sequential anaerobic–aerobic biofilm reactors packed with tire chips | |
Leduc et al. | Biotic and abiotic disappearance of four PAH compounds from flooded soil under various redox conditions | |
US6458276B1 (en) | Method and apparatus for biodegradation of alkyl ethers and tertiary butyl alcohol | |
Yang et al. | Packed entrapped mixed microbial cell process for removal of phenol and its compounds | |
Kapoor et al. | Integrative Strategies for Bioremediation of Environmental Contaminants, Volume 2: Avenues to a Cleaner Society | |
Stoner | Biotechnology for the treatment of hazardous waste | |
AU772883B2 (en) | Biological permeable barrier to treat contaminated groundwater using immobilized cells | |
US6203703B1 (en) | Method and system for bioremediation of hydrocarbon contaminated water | |
Khodadoust et al. | Solvent washing of PCP contaminated soils with anaerobic treatment of wash fluids | |
CA2372253C (en) | Biological permeable barrier to treat contaminated groundwater using immobilized cells | |
Cha et al. | Treatment technologies | |
US20030085174A1 (en) | On-site biological treatment of contaminated fluids | |
Nath et al. | Bioregeneration of spent activated carbon: effect of physico-chemical parameters | |
Razavi‐Shirazi et al. | Development of a Biological Permeable Barrier To Remove 2, 4, 6‐Trichlorophenol from Groundwater Using Immobilized Cells | |
Pichtel | Biofilms for Remediation of Xenobiotic Hydrocarbons—A Technical Review | |
JP3533296B2 (en) | Organic compound decomposition method | |
Dey et al. | Immobilized chromate reducing bacteria and their enzymes in bioremediation of hexavalent chromium | |
Razavi-Shirazi | Development of Biological Permeable Barrier to Treat Contaminated Groundwater Using PVA-Immobilized Cells | |
Portier et al. | Bioremediation of pesticide‐contaminated groundwater | |
Shim | BTEX degradation by a coculture of Pseudomonas putida and Pseudomonas fluorescens immobilized in a fibrous-bed bioreactor |
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 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL |
|
AX | Request for extension of the european patent |
Free format text: AL;LT;LV;MK;RO;SI |
|
17P | Request for examination filed |
Effective date: 20011102 |
|
A4 | Supplementary search report drawn up and despatched |
Effective date: 20030212 |
|
17Q | First examination report despatched |
Effective date: 20030514 |
|
APAZ | Date of receipt of statement of grounds of appeal deleted |
Free format text: ORIGINAL CODE: EPIDOSDNOA3E |
|
APBN | Date of receipt of notice of appeal recorded |
Free format text: ORIGINAL CODE: EPIDOSNNOA2E |
|
APBR | Date of receipt of statement of grounds of appeal recorded |
Free format text: ORIGINAL CODE: EPIDOSNNOA3E |
|
APBR | Date of receipt of statement of grounds of appeal recorded |
Free format text: ORIGINAL CODE: EPIDOSNNOA3E |
|
APBK | Appeal reference recorded |
Free format text: ORIGINAL CODE: EPIDOSNREFNE |
|
APAF | Appeal reference modified |
Free format text: ORIGINAL CODE: EPIDOSCREFNE |
|
APBT | Appeal procedure closed |
Free format text: ORIGINAL CODE: EPIDOSNNOA9E |
|
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: 20080310 |