text:
|Publication number
|Publication type
|Application number
|Publication date
|Nov 11, 2008
|Filing date
|Aug 31, 2004
|Priority date
|Jun 29, 2000
|Fee status
|Also published as
|Publication number
|Kent S. Sorenson, Jr.
|Original Assignee
|Srp Technologies, Inc.
|Export Citation
|BiBTeX, EndNote, RefMan
|Patent Citations (29), Non-Patent Citations (13), Referenced by (1), Classifications (10), Legal Events (3)
|External Links: USPTO, USPTO Assignment, Espacenet
This application is a continuation-in-part of U.S. application Ser. No. 09/895,430, filed Jun. 29, 2001, now U.S. Pat. No. 6,783,678, which claims the benefit of U.S. Provisional Application No. 60/214,957, filed Jun. 29, 2000, and U.S. Provisional Application No. 60/233,414, filed Sep. 18, 2000, which are hereby incorporated by reference.
This invention was made with United States Government support under Contract No. DE-AC07-99ID13727 awarded by the United States Department of Energy. The United States Government has certain rights in the invention.
This invention relates to remediation of environmental contamination. More particularly, the invention relates to methods for accelerating or enhancing in situ dehalogenation of nonaqueous halogenated solvents in ground water. These methods involve adding to the contaminated ground water a composition of matter that both functions as an electron donor for halorespiration processes carried out by indigenous or exogenously supplied bacteria, wherein the nonaqueous halogenated solvents are dehalogenated and degraded to innocuous compounds, and promotes mass transfer of the nonaqueous halogenated solvents from a source into the ground water where such solvents can be broken down.
For many years little care was taken in the handling of organic solvents and other materials that were used in industry and at government installations, such as military bases. Because of poor handling techniques and, occasionally, intentional dumping, many industrial sites and military bases now have contaminated areas containing relatively high concentrations of these contaminants. Chlorinated solvents, such as trichloroethylene (TCE), perchloroethylene (PCE), and other types of liquids, are common at such sites, and if not removed can infiltrate groundwater supplies, rendering the water unfit for consumption and other uses.
A variety of techniques have been used to promote the removal of such chemical contaminants, both from the soil and from the ground water. The principle method of ground water remediation currently used where dense, non-aqueous phase liquids (DNAPLs) are involved is what is commonly referred to as "pump-and-treat" remediation. According to this method, wells are drilled into the contaminated area and contaminated ground water is pumped above the surface, where it is treated to remove the contaminants.
The limitations of the pump-and-treat method have been documented in articles such as D. M. Mackay & J. A. Cherry, Groundwater Contamination: Pump and Treat Remediation, 23 Environ. Sci. Technol. 630-636 (1989). The authors of this article concluded that pump-and-treat remediation can only be relied on to contain ground water contamination through the manipulation of hydraulic gradients within an aquifer. The reasons for the failure of the pump-and-treat method to decontaminate aquifers are rooted in the limited aqueous solubility of many DNAPLs in ground water and other processes involving contaminant desorption and diffusion. Because of the low aqueous solubility of most DNAPLs, their removal by ground water extraction requires exceptionally long periods of time.
Due to the general impracticability of the pump-and-treat method, considerable attention has been paid recently to other methods for effecting remediation. One such process is commonly referred to as enhanced solubilization. This method uses micellar surfactants to increase the effective solubility of the DNAPLs to accelerate the rate of removal. The mechanism of solubilization displayed by surfactants arises from the formation of microemulsions by the surfactants, water, and the solubilized DNAPLs. For example, Table 1 shows solubilization of PCE by various nonionic and anionic surfactants. These data indicate that even dilute surfactants can significantly increase the aqueous solubility of PCE.
Solubilized (mg/l)
Nonylphenol ethoxylate and
its phosphate ester (1:1)
Sodium diamyl and dioctyl
sulfosuccinates (1:1) in 500 mg
Nonylphenol ethoxylate
A serious drawback with the surfactant-enhanced aquifer remediation is that the vertical mobility of the solubilized DNAPLs substantially requires that an aquiclude be present to catch any solubilized contaminant that migrates vertically. Many aquifers, however, lack such an aquiclude. If the traditional surfactant-enhanced aquifer remediation method were to be used with an aquifer lacking an aquiclude, there is a significant risk that the solubilized DNAPLs will spread vertically and contaminate an increasingly large volume. Another drawback of surfactant-enhanced aquifer remediation is the need to pump high concentrations of contaminated water above ground, which results in exposure risks to workers and the environment, and the need to dispose or recycle the surfactant.
Another method for effecting remediation of ground water contaminated with DNAPLs is known as enhanced bioremediation. Enhanced bioremediation, as opposed to intrinsic bioremediation, of halogenated solvent-contaminated ground water falls into the two broad categories of aerobic and anaerobic bioremediation. The aerobic processes, regardless of whether they are carried out in situ or in a bioreactor, require addition of (1) oxygen as the electron acceptor for catabolism of the halogenated solvents, and (2) a carbon source, such as methane, propane, phenol, toluene, or butane. The utilization of an appropriate carbon source induces an enzyme that fortuitously degrades many halogenated solvents, but without any immediate benefit to the microorganisms involved. This process has been applied in situ to aqueous contamination in several instances, and at least one patent has been granted for this approach (U.S. Pat. No. 5,384,048). It has also been used to treat aqueous contamination in above-ground bioreactors with numerous variations, especially using proprietary microorganisms and nutrient mixes. Many patents have been granted in this area, e.g., U.S. Pat. Nos. 5,057,221; 5,962,305; 5,945,331.
Anaerobic bioremediation of halogenated solvents is a fundamentally different process than aerobic bioremediation. Under appropriate anaerobic conditions, chlorinated solvents can be used directly by some microorganisms as electron acceptors through a process that has come to be known as "chlororespiration," or, more generally, "halorespiration." D. L. Freedman & J. M. Gossett, Biological Reductive Dechlorination of Tetrachloroethylene and Trichloroethylene to Ethylene Under Methanogenic Conditions, 55 Applied Environ. Microbiol. 2144-2155 (1989), first published the complete degradation pathway for chlorinated ethenes to ethene. In the following years, several publications reported evidence that the degradation could be achieved through microbial respiration, indicating that the microorganisms could actually grow by using chlorinated solvents directly as electron acceptors. The primary requirement to facilitate this process is the addition of a suitable electron donor or carbon source. Many electron donors have been described in the literature, including acetate, lactate, propionate, butyrate, formate, ethanol, hydrogen, and many others. U.S. Pat. No. 5,277,815 issued in 1994 for in situ electron donor addition along with control of redox conditions to effect the desired end products. U.S. Pat. No. 5,578,210 issued later for enhanced anaerobic in situ bioremediation using "biotransformation enhancing agents," i.e., electron donors such as propylene glycol, glycerol, glutamate, a mixture of proteose peptone, beef extract, yeast extract, malt extract, dextrose, and ascorbic acid, and mixtures thereof. Based primarily on what was publicly available in the scientific literature, studies of enhanced anaerobic in situ bioremediation of chlorinated solvents began in the mid-1990s. This approach generally includes electron donor addition, sometimes with other micronutrients, to facilitate biotransformation of aqueous-phase contaminants. To date, only a few large-scale studies have been published in the peer-reviewed literature, but environmental consulting companies and remediation contractors are increasingly using the general approach.
With one very recent exception, discussed below, all of the work done in this area to date has focused on the biodegradation of aqueous contaminants, because microorganisms cannot directly degrade nonaqueous contaminants. Consequently, bioremediation is not generally thought to be applicable to sites with residual DNAPLs in the subsurface. Therefore, the technologies currently in use include thermal technologies such as steam stripping, in situ chemical oxidation, surfactant flushing, or co-solvent flushing. Surfactant (or co-solvent) flushing, briefly described above, is a chemical process that aims to facilitate transport of nonaqueous contaminants, but without attention to biodegradation. At many sites, however, the pump-and-treat process continues to be used to hydraulically contain residual source areas although it is almost universally accepted that these systems will have to operate in perpetuity because of their inefficient removal of nonaqueous contaminants.
The notable recent exception to the focus of bioremediation on aqueous contaminants away from residual source areas is a study by C. S. Carr et al., Effect of Dechlorinating Bacteria on the Longevity and Composition of PCE-Containing Nonaqueous Phase Liquids under Equilibrium Dissolution Conditions, 34 Environ. Sci. Technol. 1088-1094 (2000), demonstrating that anaerobic bioremediation of tetrachloroethene (PCE) enhanced mass transfer from the nonaqueous phase to the aqueous phase and significantly shortened the longevity of the nonaqueous source. The mechanisms identified were (1) enhanced dissolution of PCE resulting from the continuous removal of the compound from the aqueous phase by bacteria, and (2) increased solubility of the intermediate chlorinated ethenes relative to PCE, allowing the total moles of chlorinated ethenes in the aqueous phase to increase due to biotransformation. This study is important because it identifies some of the advantages of enhancing mass transfer from the nonaqueous phase to the aqueous phase.
In view of the foregoing, it will be appreciated that providing methods for accelerating or enhancing in situ bioremediation of halogenated solvents in ground water would be a significant advancement in the art.
It is a feature of the present invention to provide a method for in situ remediation of DNAPLs in ground water wherein capital costs are low.
It is also a feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein mass transfer from the nonaqueous phase to the aqueous phase is enhanced.
It is another feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein the longevity of source areas is shortened.
It is still another feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein no extraction of contaminated water from the ground is required.
It is yet another feature of the invention to provide a method for in situ remediation of DNAPLs in ground water such that the concentrations of the solvents are restored to below regulatory limits and no follow-on remediation activities, other than perhaps monitored natural attenuation, are needed.
It is a still further feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein the DNAPLs are more rapidly removed from the ground water than with prior art methods and residual source areas are removed.
It is another feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein transport is facilitated and bioavailability of nonaqueous halogenated solvents is enhanced.
It is still another feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein the method is sustainable for low cost and has low maintenance requirements.
It is yet another feature of the invention to provide a method for in situ remediation of DNAPLs in ground water by adding a composition of matter that is both an electron donor and a surfactant or enhancer of mass transfer.
It is still further an feature of the invention to provide a method for remediation of DNAPLs in ground water wherein destruction of the DNAPLs occurs in situ.
It is a yet further feature of the invention to provide a method for in situ remediation of DNAPLs in ground water wherein an unobtrusive appearance is provided and it meets with public acceptance.
These and other advantages can be addressed by providing a method for enhancing in situ bioremediation of a nonaqueous halogenated solvent in ground water comprising adding to the ground water an amount of an electron donor sufficient for a halo-respiring microbe in the ground water to use the nonaqueous halogenated solvent as an electron acceptor, thereby reductively dehalogenating the nonaqueous halogenated solvent into innocuous compounds, wherein the electron donor enhances mass transfer of the nonaqueous halogenated solvents into solution. The electron donor functions as a surfactant or co-solvent. In cases where the electron donor is a functional surfactant, it can be added at a concentration above the critical micelle concentration in water, although this is not required. In cases where the electron donor is a functional co-solvent, there may be no critical micelle concentration, or if there is a critical micelle concentration in water, the electron donor can be added at a concentration below such critical micelle concentration. Illustrative electron donors for use in this method include C2-C4 carboxylic acids and hydroxy acids, salts thereof, esters of C2-C4 carboxylic acids and hydroxy acids, and mixtures thereof. In an illustrative embodiment of the invention, the electron donor is a member selected from the group consisting of lactic acid, salts thereof, lactate esters, and mixtures thereof. Illustrative salts of lactic acid include sodium lactate, potassium lactate, lithium lactate, ammonium lactate, calcium lactate, magnesium lactate, manganese lactate, zinc lactate, ferrous lactate, aluminum lactate, and mixtures thereof, wherein sodium lactate is especially illustrative. Illustrative targets of the method include nonaqueous chlorinated solvents, such as perchloroethylene (PCE), trichloroethylene (TCE), dichloroethylene (DCE), vinyl chloride (VC), 1,1,1-trichloroethane (TCA), carbon tetrachloride and less chlorinated derivatives thereof, and mixtures thereof. An illustrative aspect of the invention relates to enhancing the reductive dehalogenation activity of indigenous halo-respiring microbes present in the ground water. If halo-respiring microbes are absent or ineffective, then such microbes can be exogenously supplied to the ground water. Illustratively, the microbes are bacteria, such as Dehalococcoides ethenogenes strain 195, the Pinellas culture, and the like, and mixtures thereof. The method degrades the halogenated solvents into innocuous compounds such as ethylene, ethane, carbon dioxide, water, halogen salts, and mixtures thereof.
A method for enhancing mass transfer of a nonaqueous halogenated solvent present in a nonaqueous residual source of contamination into the aqueous phase comprises adding to the ground water an effective amount of a composition that donates electrons for reductive dehalogenation of the nonaqueous halogenated solvent and functions as a surfactant for solubilizing the nonaqueous halogenated solvent.
A method for enhancing bioremediation of a nonaqueous chlorinated solvent in ground water comprises adding to the ground water an amount of an electron donor sufficient for a chloro-respiring microbe to use the nonaqueous chlorinated solvent as an electron acceptor, thus reductively dechlorinating the nonaqueous chlorinated solvent, wherein said electron donor comprises, illustratively, about 0.025% to about 3% by weight, or about 0.1% to about 3% by weight, or about 1% to about 3% by weight, or about 60% to about 100% by weight, of a member selected from the group consisting of C2-C4 carboxylic acid and salts thereof, C2-C4 hydroxy acids and salts thereof, and mixtures thereof. Illustrative of such carboxylic and hydroxy acids are lactic acid, propionic acid, butyric acid, and mixtures thereof. The electron donor further can further comprise a member selected from the group consisting of esters of C2-C4 carboxylic acids, esters of C2-C4 hydroxy acids, and mixtures thereof, such as esters of lactic acid. The electron donor can comprise such esters in an amount of about 0.1 to about 10% by weight.
Another illustrative method for enhancing bioremediation of a nonaqueous chlorinated solvent in ground water comprises adding to the ground water an amount of an electron donor sufficient for a chloro-respiring microbe to use the nonaqueous chlorinated solvent as an electron acceptor, thus reductively dechlorinating the nonaqueous chlorinated solvent, wherein said electron donor comprises greater than about 150 times the minimum reducing equivalents necessary for complete reduction of PCE to ethene of a member selected from the group consisting of C2-C4 carboxylic acid and salts thereof, C2-C4 hydroxy acids and salts thereof, and mixtures thereof.
Still another illustrative method for enhancing bioremediation of a nonaqueous chlorinated solvent in ground water comprises adding to the ground water an amount of an electron donor sufficient for a chloro-respiring microbe to use the nonaqueous chlorinated solvent as an electron acceptor, thus reductively dechlorinating the nonaqueous chlorinated solvent, wherein said electron donor comprises greater than about 2500 times the concentration of the nonaqueous chlorinated solvent of a member selected from the group consisting of C2-C4 carboxylic acid and salts thereof, C2-C4 hydroxy acids and salts thereof, and mixtures thereof. Illustrative amounts of such carboxylic and hydroxy acids and mixtures thereof are in the range of about 0.025% to about 100% by weight.
Yet another illustrative method according to the present invention relates to a method for increasing desorption of sorbed-phase nonaqueous chlorinated solvent contamination in dissolved plume areas in ground water, the method comprising adding an electron donor to the ground water, wherein the electron donor comprises about 0.025% to about 100% by weight of a member selected from the group consisting of C2-C4 carboxylic acid and salts thereof, C2-C4 hydroxy acids and salts thereof, and mixtures thereof. Sodium lactate is illustrative of such electron donors.
Before the present methods for accelerating or enhancing in situ bioremediation of halogenated solvents in ground water are disclosed and described, it is to be understood that this invention is not limited to the particular configurations, process steps, and materials disclosed herein as such configurations, process steps, and materials may vary somewhat. It is also to be understood that the terminology employed herein is used for the purpose of describing particular embodiments only and is not intended to be limiting since the scope of the present invention will be limited only by the appended claims and equivalents thereof.
The publications and other reference materials referred to herein to describe the background of the invention and to provide additional detail regarding its practice are hereby incorporated by reference. The references discussed herein are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the inventors are not entitled to antedate such disclosure by virtue of prior invention.
It must be noted that, as used in this specification and the appended claims, the singular forms "a," "an," and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "an electron donor" includes reference to a mixture of two or more of such electron donors, reference to "a solvent" includes reference to one or more of such solvents, and reference to "a microbe" includes reference to a mixture of two or more of such microbes.
In describing and claiming the present invention, the following terminology will be used in accordance with the definitions set out below.
As used herein, "comprising," "including," "containing," "characterized by," and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps. "Comprising" is to be interpreted as including the more restrictive terms "consisting of" and "consisting essentially of."
As used herein, "consisting of" and grammatical equivalents thereof exclude any element, step, or ingredient not specified in the claim.
As used herein, "consisting essentially of" and grammatical equivalents thereof limit the scope of a claim to the specified materials or steps and those that do not materially affect the basic and novel characteristic or characteristics of the claimed invention.
As used herein, "PCE," "perchloroethylene," "tetrachloroethylene," and "tetrachloroethene" refer to Cl2C═CCl2.
As used herein, "TCE," "trichloroethylene," and "trichloroethene" refer to Cl2C═CH—Cl.
As used herein, "DCE," "dichloroethylene," and "dichloroethene" refer to Cl—HC═CH—Cl.
As used herein, "VC" and "vinyl chloride" refer to H2C═CH—Cl.
As used herein, "ethylene" and "ethene" refer to H2C═CH2.
As used herein, "chloroethenes" means PCE, TCE, DCE, VC, and mixtures thereof.
As used herein, "biotransformation" means a biological reduction in the number of halogen, e.g., chlorine, atoms covalently bound to an organic compound. For example, PCE can be biotransformed to TCE, which can be biotransformed to DCE, which can be biotransformed to vinyl chloride, which can be biotransformed to ethylene. If the rate of biotransformation is increased by adding an electron donor to the ground water, then the biotransformation is enhanced.
As used herein, "microbe" means a microscopic organism, such as bacteria, protozoa, and some fungi and algae. Bacteria are especially illustrative microbes according to the present invention. Biotransformation is enhanced, at least in part, by stimulating indigenous, naturally occurring microbes in the ground water. If indigenous, naturally occurring microbes are not present or are not sufficiently effective, then an appropriate microbe can be added to the ground water, as well as the electron donor of the present invention. The microbe can be added before, with, or after adding the electron donor to the ground water. Illustratively, the microbe is an anaerobic or facultatively anaerobic bacterium. Bacteria known to work within the current processes include Dehalococcoides ethenogenes strain 195 (X. Maymo-Gatell et al., Isolation of a Bacterium that Reductively Dechlorinates Tetrachloroethene to Ethene, 276 Science 1568-1571 (1997)), the Pinellas culture (M. R. Harkness et al., Use of Bioaugmentation To Stimulate Complete Reductive Dechlorination of Trichloroethene in Dover Soil Colunms, 33 Environmental Sci. Technol. 1100-1109 (1999); D. E. Ellis et al., Bioaugmentation for Accelerated In Situ Anaerobic Bioremediation, 34 Environmental Sci. Technol. 2254-2260 (2000)), and the like, and mixtures thereof. Other species, however, are known to function, and the present invention is not limited by the examples provided herein.
As used herein, "surfactant" means a substance that when dissolved in water or an aqueous solution reduces its surface tension or the interfacial tension between it and another liquid. Surfactants are characterized by a structural balance between one or more hydrophilic and hydrophobic groups. This amphiphilic nature causes them to be preferentially adsorbed at air-water, oil-water, and solid-water interfaces, forming oriented monolayers wherein the hydrophilic groups are in the aqueous phase and the hydrocarbon chains are pointed toward the air, in contact with the solid surfaces, or immersed in the oil phase. Surfactants are characterized by a critical micelle concentration (cmc), a concentration at which surfactant molecules begin to aggregate into micelles and above which more micelles are formed. Surfactants enhance solubility of nonpolar compounds in aqueous solutions by providing a microenvironment, i.e., the interior of micelles, where the nonpolar compounds can accumulate. In certain illustrative embodiments of the present invention, the electron donor is a surfactant.
As used herein, a "co-solvent" is a solvent present in a minor amount as compared to a solvent with which it is mixed. Co-solvents are like surfactants in that they decrease interfacial tension between two liquid phases, but they generally do not form micelles. Thus, co-solvents enhance solubility, but not to the extent of surfactants. In the context of in situ bioremediation, the rate of enhanced solubilization mediated by a co-solvent or co-solvents is less likely to overwhelm the rate of biotransformation. Thus, in certain illustrative embodiments of the invention, the electron donor is a co-solvent.
Chlorinated solvents represent two of the three most common ground water contaminants at hazardous waste sites in the United States, and with their degradation products they account for eight of the top 20. Unfortunately, chlorinated solvents are relatively recalcitrant compounds with low, but toxologically significant, solubilities in water. Historically, the conventional technology for ground water treatment has been pump-and-treat methodology. While the pump-and-treat approach can be useful for achieving hydraulic containment of a ground water contaminated with chlorinated solvents, it has very rarely been successful for restoration, largely because of the heterogeneity of the subsurface (i.e., preferential flow paths) and the presence of nonaqueous phase liquids. This has led to significant research in the last 10 years on in situ technologies for restoration of ground water contaminated with chlorinated solvents.
Residual chlorinated solvent source areas (where nonaqueous contaminants are present) in the subsurface are especially problematic because the combination of low contaminant solubilities and the lack of mixing in typical ground water flow makes them very long-lived (decades to centuries). As discussed above, the common perception that bioremediation cannot effect improvements to the slow mass transfer from the nonaqueous to the aqueous phase has limited its applications to aqueous-phase contaminated ground water plumes. Also mentioned above, the technology categories used for these areas other than pump-and-treat include thermal technologies such as stream-stripping, in situ chemical oxidation, surfactant flushing, or co-solvent flushing. While these approaches generally result in some rapid mass removal of contaminants and have worked to varying degrees, they all share a common disadvantage: they have a high capital cost in the early stages of remediation. In addition, all except chemical oxidation require extraction of contaminants from the ground with subsequent treatment. This creates new exposure pathways and increases costs. Finally, these technologies rarely restore ground water to contaminant concentrations below regulatory limits, so follow-on activities are generally required.
P. V. Roberts et al., Field Study of Organic Water Quality Changes during Ground Water Recharge in the Palo Alto Baylands, 16 Water Resources Research 1025-1035 (1982), reported one of the first field observations suggesting bioremediation of chloroethenes (PCE, TCE, DCE, and VC). E. J. Bouwer & P. L. McCarty, Transformation of 1- and 2-Carbon Halogenated Aliphatic Organic Compounds under Methanogenic Conditions, 45 Applied Environ. Microbiol. 1286-1294 (1983), confirmed biodegradation of PCE and TCE in the laboratory shortly thereafter. F. Parsons et al., Transformations of Tetrachloroethylene and Trichloroethylene in Microcosms and Groundwater, 76 J. Am. Water Works Ass'n 56-59 (1984), and T. M. Vogel & P. L. McCarty, Biotransformation of Tetrachloroethylene to Trichloroethylene, Dichloroethylene, Vinyl Chloride, and Carbon Dioxide under Methanogenic Conditions, 49 Applied Environ. Microbiol. 1080-1083 (1985), demonstrated that DCE and VC were generated during biodegradation of PCE under anaerobic conditions. Finally, Freedman and Gossett, supra, reported complete dechlorination of PCE to ethylene as follows: PCE→TCE→DCE→VC→ethylene. In each step of the process the compound was reduced (gaining two electrons) through substitution of a chlorine atom by a hydrogen atom. Hence this degradation pathway is often referred to as anaerobic reductive dechlorination (ARD).
In the anaerobic reductive dechlorination process, chloroethenes act as electron acceptors. This implies that the process can be limited in the field by the availability of sufficient suitable electron donors. In fact, reductive dechlorination also can be totally or partially inhibited by the presence of competing inorganic electron acceptors, such as oxygen, nitrate, iron, and sulfate. It is now widely accepted that anaerobic reductive dechlorination occurs to some extent at most field sites where chloroethene contamination exists in the presence of a sufficient supply of electron donors (P. L. McCarty, Biotic and Abiotic Transformations of Chlorinated Solvents in Groundwater, in Symposium on Natural Attenuation of Chlorinated Organics in Ground Water 5-9 (Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C., EPA/540/R-96/509, 1996); J. M. Gossett & S. H. Zinder, Microbiological Aspects Relevant to Natural Attenuation of Chlorinated Ethenes, in Symposium on Natural Attenuation of Chlorinated Organics in Ground Water 10-13 (Office of Research and Development, U.S. Environmental Protection Agency, Washington, D.C., EPA/540/R-96/509, 1996); T. H. Wiedemeier et al., Technical Protocol for Evaluating Natural Attenuation of Chlorinated Solvents in Groundwater, Draft—Revision 1 (Air Force Center for Environmental Excellence, Technology Transfer Division, Brooks Air Force Base, San Antonio, Tex., 1997).
Many oxidizable organic compounds potentially could make suitable electron donors. For a potential electron donor to be useful as an amendment for enhanced in situ bioremediation, however, it must be safe to use, facilitate the desired reaction, and be relatively inexpensive. Lactate is a potential electron donor having these properties. It is innocuous enough for use in the food and medical industries. It has been demonstrated to facilitate anaerobic reductive dechlorination of chlorinated solvents in several laboratory studies (e.g., W. P. DeBruin et al., Complete Biological Reductive Transformation of Tetrachloroethylene to Ethane, 58 Applied Environ. Microbiol. 1996-2000 (1992); S. A. Gibson & G. W. Sewell, Stimulation of Reductive Dechlorination of Tetrachloroethene in Anaerobic Aquifer Microcosms by Addition of Short-Chain Organic Acids or Alcohols 1392-1393 (1992), D. E. Fennel et al., Comparison of Butyric Acid, Ethanol, Lactic Acid, and Propionic Acid as Hydrogen Donors for Reductive Dechlorination of Tetrachloroethene, 31 Environ. Sci. Technol. 918-926 (1997). The cost-effectiveness of lactate has not been thoroughly evaluated, but preliminary testing suggests that it will be at least as cost-effective as other in situ remediation technologies.
While the use of lactate as an electron donor to facilitate anaerobic reductive dechlorination is well-established, it has only been applied for remediation of aqueous-phase contaminants because of the perception that bioremediation does not significantly enhance mass transfer of contaminants from the nonaqueous phase. It is shown herein, however, that the addition of high concentrations of a lactate solution not only facilitates reductive dechlorination of aqueous chloroethenes, but also significantly enhances mass transfer of nonaqueous contaminants, making them highly bioavailable. As used herein, "high concentrations" means high relative to the stoichiometric requirement for electron donor to degrade TCE to ethene. Thus, "high concentrations" means about 3-5 orders of magnitude greater than such stoichiometric requirements.
Facilitated transport and enhanced bioavailability of nonaqueous chlorinated solvents through addition of high concentrations of an appropriate electron donor, according to the present invention, take advantage of the natural processes that have made natural attenuation so popular, while also significantly reducing source longevity by enhancing mass transfer to the aqueous phase. The capital costs of the approach are minimal, because only a simple, potentially portable, injection system and monitoring wells are required. Initial mass removal may be slower than some of the other technologies, but it is sustainable for a relatively low cost and requires no extraction of contaminated ground water except for routine monitoring.
High concentrations of lactate, for example, not only provide an electron donor to expedite anaerobic reductive dechlorination, but also facilitate mass transfer of the nonaqueous chlorinated solvents into the aqueous phase in a manner that makes them highly bioavailable. The lactate appears to act as a surfactant or co-solvent that brings nonaqueous chlorinated solvents into solution. The intimate contact of the chlorinated solvents (electron acceptors) in solution with the lactate (electron donor) enhances bioavailability and leads to rapid biodegradation. The depletion of the residual contamination source is potentially greatly accelerated due to the surfactant or co-solvent effect. The use of lactate to facilitate transport of chlorinated solvents into the aqueous phase and dramatically increase their bioavailability opens up a wide range of applications for enhanced in situ bioremediation of chlorinated solvents present as nonaqueous phase liquids at residual saturation in ground water. The use of a relatively inexpensive compound that accomplishes the same thing as mild surfactants or co-solvents, but does not require extraction and above-ground treatment, combines the advantages of mass removal with those of enhanced bioremediation.
All of the advantages of bioremediation, such as low capital cost, in situ contaminant destruction, unobtrusive appearance, public acceptance, low maintenance requirements, and the like, can be applied to residual source areas because, using this process, source longevity can potentially be greatly reduced. Many of these benefits are enjoyed by owners of contaminated sites, but reduced risk of further releases of contaminants to the public and the environment is also important.
The most appropriate application of this process is to sites with residual chlorinated solvent source areas in the subsurface, comprising primarily nonaqueous contaminants at residual saturation. These are common at both federal and industrial facilities. When very large, mobile DNAPL pools are present, mass transfer rates may be too slow to effect remediation in a reasonable time frame, and more aggressive, capital-intensive approaches may be warranted.
A 1-year field evaluation of enhanced in situ bioremediation was performed at Test Area North ("TAN") of the Idaho National Engineering and Environmental Laboratory.
The initial electron donor addition strategy involved continuous injection of potable water at 37.85 liters/minute (10 gpm) into Well TSF-05. The electron donor was to be pulsed into this line biweekly. The potable water injection began on Nov. 16, 1998, at the beginning of the startup sampling period. Potable water injection was discontinued on Dec. 11, 1998, due to a significant depression of chlorinated ethene concentrations near the injection well. It was determined that the continuous injection of clean water at 37.85 liters/minute (10 gpm) overwhelmed the flux of contaminants from the secondary source. This condition was considered undesirable for evaluation of an in situ technology, so the electron donor addition strategy was modified such that potable water was only injected for 1 hour following injection of the electron donor solution to flush the solution into the formation surrounding the injection well. This was intended to prevent significant quantities of electron donor from collecting in the injection well and to help prevent biofouling.
The raw electron donor solution used was food grade sodium lactate. Table 2 presents the injection date, the sodium lactate concentration in percent by weight, the injection rate in units of gallons per minute, the total volume of electron donor injected in gallons, and the volume in gallons of potable water injected at 75.7 liters/minute (20 gpm) to flush the solution into the formation. Lactate injections began on Jan. 7, 1999, and were continued until Sep. 8, 1999. Four injection solution concentrations were used, each being more dilute than the previous solution. The dilutions were made in an effort to keep the lactate in the upper part of the aquifer, reducing density effects that cause the electron donor solution to sink to the base of the aquifer. Because the total mass of lactate was kept constant, and the injection flow rate was not dramatically increased, the duration of injection increased from 30 minutes to 4 hours.
Sodium Lactate
Total Volume
Rate (gpm)
Injected (gal)
Jan. 7, 1999
Jan. 12, 1999
Jan. 19, 1999
Feb. 2, 1999
Feb. 9, 1999
Feb. 16, 1999
Feb. 23, 1999
Mar. 2, 1999
Mar. 4, 1999
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Eleven monitoring wells (i.e., TAN-D2, TAN-9, TAN-10A, TAN-25, TAN-26, TAN-27, TAN-28, TAN-29, TAN-30A, TAN-31, and TAN-37) were sampled biweekly and analyzed for electron donors, biological activity indicators, competing inorganic electron acceptors and their reduced products, chloroethenes, ethene, pH, temperature, and specific conductivity.
Electron Donor Distribution. Because concentrated lactate solutions are denser than water, their injection into an aquifer can cause density-driven flow downward in the aquifer. At TAN, some density-driven flow was desirable during lactate addition because the zone to be treated was approximately 60 m thick but the injection well (TSF-05) was completed only in the upper 30 m. It was apparent after the first month of injections, however, that too much of the lactate solution was moving into the lower half of the zone before spreading horizontally in the upper half of the zone. For this reason, the concentration of the lactate was reduced and the injection duration was increased in steps over several months. The importance of the lactate addition strategy can be seen in well TAN-31, a cross-gradient well completed in the upper half of the treatment zone approximately 15 m from the injection well (
Redox Conditions and Reductive Dechlorination. The effect of lactate addition on redox conditions, and ultimately on reductive dechlorination, is evident in
Enhanced reductive dechlorination of TCE to ethene was observed in all wells receiving significant lactate concentrations.
Based on the results of the field evaluation, enhanced in situ bioremediation was selected to replace pump-and-treat for remediation of the residual contaminant source area at Test Area North. Of particular importance in the decision process was the fact that the process was effective not only for degrading chlorinated solvents in the aqueous phase, but also that the process seemed to have a significant impact on the residual source itself.
Enhanced Bioavailability. A surprising observation during the field evaluation was a dramatic increase in TCE concentrations deep in the aquifer soon after sodium lactate addition began (
A second possible explanation for increased TCE concentrations in well TAN-26 is that the lactate injection led to facilitated transport of the organic contaminants. Three hypotheses that could explain facilitated transport are as follows: (1) that the lactate solution acts as a co-solvent for the organic contaminants, (2) that the lactate acts as a surfactant, and (3) that the lactate solution, because of its high concentration, displaces sorbed chlorinated ethenes, driving them into solution. All of these mechanisms would result in facilitated transport of the chlorinated ethenes in intimate contact with the lactate solution and would make more of the chlorinated ethenes bioavailable. The behavior of the TCE in well TAN-26 after the peak concentration suggests that it was, in fact, extremely bioavailable. The drop in TCE concentration from the peak concentration to undetectable levels occurred with a TCE half-life of less than 20 days (assuming first-order kinetics for illustration). Just as important for the facilitated transport hypothesis, cis-DCE increased to a peak concentration within 20% of the peak TCE concentration (indicating an excellent mass balance), and then remained elevated near that peak concentration. The significance of this point is that the lactate injection was continuing, so if the hypothesis were valid it would be expected to continue bringing the organic contaminants with it as it migrated through the secondary source. After biological activity increased, the TCE was transformed to cis-DCE before reaching well TAN-26, but as shown in
The facilitated transport makes available for reductive dechlorination large quantities of the chlorinated ethenes that otherwise would remain associated with the secondary source. As shown by the well TAN-26 data, once made available by the lactate solution, the TCE was, in fact, rapidly degraded. Enhanced bioavailability of chlorinated ethenes in the secondary source would greatly decrease the longevity of the source.
Based on the field results presented in Example 1, laboratory studies were performed to confirm that the enhanced bioavailability of TCE observed in the field was due to co-solvent or surfactant behavior resulting from the use of high concentrations of sodium lactate. Two fundamental properties used to screen the co-solvent or surfactant properties of a solution are surface tension and interfacial tension. Surface tension measures the force per unit length along the interface between a liquid and air due to its tension. When a co-solvent or surfactant is present in an aqueous liquid at increasing concentrations, the surface tension of that liquid decreases. Interfacial tension is similar to surface tension except that it measures the force per unit length along the interface between two liquid phases arising from the surface free energy. The higher the interfacial tension between two liquids, the less likely one is to dissolve into the other, and the more difficult it is for one to be transported within the other. Thus, perhaps the most significant property of co-solvents and surfactants in the context of chlorinated solvent remediation is that they decrease the interfacial tension between the aqueous phase (groundwater) and the organic nonaqueous phase so that the solubility (or mobility for order-of-magnitude decreases) of the nonaqueous phase is enhanced.
The laboratory study performed to confirm the co-solvent properties of the high concentration electron donor solution measured the surface tension of electron donor solutions at various concentrations. Next, interfacial tensions between the same electron donor solutions and nonaqueous phase TCE were measured. Two types of electron donor solutions were used. The first was different concentrations of sodium lactate, the electron donor used in Example 1. The second was various mixtures of sodium lactate and ethyl lactate. Ethyl lactate was chosen because it is a lactate-based compound that is used in some industries as a solvent. Thus it was believed ethyl lactate might further enhance the co-solvent behavior observed, while still acting as a suitable electron donor for bioremediation. It is believed that mixtures of sodium lactate and ethyl lactate have never before been used for bioremediation. Surface and interfacial tension measurements were made using the pendant drop method (M. J. Rosen, ed., Structure/Performance Relationships in Surfactants, American Chemical Society, Washington D.C. 329 (1984); R. D. Bagnall & P. A. Arundel, The Profile Area of Pendant Drops, 82 J. Phys. Chem. 898 (1978)) coupled with real-time video imaging (M. D. Herd et al., Interfacial Tensions of Microbial Surfactants Determined by Real-Time Video Imaging of Pendant Drops, Proceedings paper number SPE/DOE 24206 513-519, SPE/DOE Eighth Symposium on Enhanced Oil Recovery, Tulsa, Okla. (1992)).
The results of the surface tension experiment are shown in
In an effort to decrease the sodium lactate concentrations required to lower the surface tension of the solution, mixtures with ethyl lactate were evaluated. As seen in
The results of the interfacial tension measurements are shown in
As ethyl lactate was added to the sodium lactate solutions, it is clear that the ethyl lactate concentration is the primary factor affecting interfacial tension.
Site Background. A site-wide Remedial Investigation (RI) identified a chlorinated solvent plume in a sandy aquifer approximately 35 to 60 feet (10.7 to 18.3 m) below ground surface at the 164th Airlift Wing at the Tennessee Air National Guard Site, Memphis, Tenn. The plume area targeted for treatment was over 2 acres (0.81 hectares). This unconfined saturated interval is overlain by an inorganic loess vadose zone and is separated from the deeper regional aquifer by a clay unit. PCE concentrations ranged from 5 to 1,000 μg/L in the target area, while TCE ranged from 100 to greater than 15,000 μg/L in the injection/monitoring wells. The aquifer initially exhibited conditions ranging from aerobic to mildly reducing. A pilot test of a sodium lactate injection system to enhance natural reductive dechlorination in the groundwater was approved by the Tennessee Department of Environment and Conservation, the Memphis and Shelby County Health Department, and the Shelby County Ground Water Control Board.
System Design. A three-dimensional model to simulate groundwater flow was developed using the MODFLOW simulator (U.S. Geological Survey). Once calibrated, model simulations were used to determine the optimal injection well locations, as well as the rate and duration of injection. Based on the results of other sodium lactate injection sites, a period of 60 days between injections was assumed. The optimal configuration was determined to be a 9-well injection system at an injection rate of 10 gallons per minute (gpm; 37.8 liters/minute) for 5 days. Results of the model (
Potable water was mixed with 60% sodium lactate to create a 1% solution. An existing 8-inch (20.3-cm) water line was tapped and connected to the distribution control header via a 4-inch (10.2-cm) line, which was housed in a portable 12-ft�14-ft (3.6-m�4.3-m) building. A double-check valve assembly was installed on the 4-inch (10.2-cm)water line to prevent back-siphoning of the injection solution into the 8-inch (20.3-cm) potable water line. Following a mixing zone with the potable water, the resulting 1% solution was delivered to the nine injection wells.
Individual valves for each injection well controlled flow leaving the distribution control header. Each line had its own flow meter and sampling port. The injection lines were approximately 2 feet (0.6 m) below grade for freeze protection. A directional boring machine was used to install most of the 2-inch (5.1-cm) diameter high-density polyethylene injection lines.
After review of all available site data, a required volume of approximately 450 gallons (1701 liters) of a sodium lactate solution per well was selected. This required mass loading, combined with the hydraulic requirements for dispersion generated by the model (10 gpm (37.8 liters/min) for 5 days), required injection of the 60% sodium lactate solution into the distribution control header at a feed rate of about 1.5 gpm (5.7 liters/min). The 1% sodium lactate solution was delivered to each of the nine individual injection wells at the required 10 gpm (37.8 liters/min). Following a 9-hour injection period, the sodium lactate pump was turned off, and 10 gpm (37.8 liters/min) per well of 100% potable water continued for 15 hours to ensure adequate distribution into the aquifer. This cycle was repeated four times. A fifth 9-hour injection was followed by 1-hour injection of 100% potable water to minimize biofouling.
Monitoring. The monitoring network included nine injection wells and six monitoring wells. Sampling was conducted bimonthly during the week prior to each lactate injection. Analysis was carried out for acetic acid, lactic acid, butanoic acid, propanoic acid, chemical oxygen demand (COD), alkalinity, ammonia, phosphate, nitrate, ferrous iron, sulfate, methane, volatile organic compounds, ethene, ethane, pH, specific conductivity, temperature, dissolved oxygen, oxidation/reduction potential, and static water level.
Electron Donor Distribution. The distribution of sodium lactate after injection into the nine injection wells was assessed using the COD parameter. The COD parameter provides an adequate representation of lactate and its degradation in the subsurface. H. Bullock, R. A. Wymore & K. S. Sorenson, Monitoring Enhanced In Situ Bioremediations in a Fractured Basalt Aquifer, in Contaminated Site Remediation: From Source Zones to Ecosystems, Proceedings of the 2000 Contaminated Site Remediation Conference 217-224 (C. D. Johnston ed., Centre for Groundwater Studies, Wembley W. A., Australia 2000).
As shown in
Redox Conditions. Despite some heterogeneity with respect to COD distribution, lactate injection had a significant impact on redox conditions throughout most of the entire treatment area. For anaerobic reductive dechlorination (ARD) of chloroethenes to proceed at a rate meaningful for full-scale remediation, the process must be energetically favorable. To be energetically favorable, the complete transformation of PCE to ethene by ARD requires the absence of the competing electron acceptors, oxygen, nitrate, iron, manganese, and sulfate. In other words, for ARD of TCE to proceed to ethene, the redox conditions within the aquifer must be methanogenic. Methanogenic conditions are indicated by the absence of nitrate and sulfate and the presence of ferrous iron and methane. Thus, the concentrations of nitrate, ferrous iron, sulfate, and methane were used to describe the redox conditions at locations through the treatment area to determine whether the conditions for complete ARD had been created.
Redox conditions in the treatment area were aerobic to mildly reducing prior to lactate injection (
The impact of lactate injection on redox conditions was immediate. Evidence of sulfate reduction was observed in 10 of 15 wells during the first sampling event following injection (about 6 weeks later), and methanogenesis was first observed within 6 months of lactate injection. After four lactate injections, significant methanogenic activity was observed throughout most of the entire treatment area (
Distribution of Dechlorination Activity.
Unlike IW-5, monitoring well 03-020MW appeared to be relatively buffered from hydraulic influences (
After 8 months and 4 lactate injections, TCE concentrations were below detectable levels and/or the maximum contaminant level (MCL), and cis-DCE was the dominant compound present in 10 of 15 wells. Three out of 15 wells showed concentrations of all chloroethenes below the respective MCLs. The remaining wells, 03-010MW and 03-020MW, still contained concentrations of TCE of approximately 50 and 130 μg/L, respectively; however, these wells also showed stoichiometric conversion of TCE to cis-DCE, and significant decreases from the pre-lactate TCE concentration of around 5,690 and 4,600 μg/L, respectively.
Finally, chloroethene concentrations at a monitoring well located approximately 100 feet downgradient of the treatment area were consistent with historical values, indicating that significant levels of primary contaminants were not being simply displaced downgradient due to lactate injection.
Extent of Dechlorination. As described above, ARD of TCE to cis-DCE was observed at the majority of wells within the treatment area. However, the dominant ARD product was cis-DCE. The advanced ARD products VC and ethene were not observed in significant concentrations during the test period. Prior to lactate injections, analyses were performed at six site wells for the presence of Dehalococcoides ethenogenes (DHE), the only organism isolated to date that is capable of the complete transformation of PCE to ethene. X. Maymo-Gatell et al., Isolation of a Bacterium That Reductively Dechlorinates Tetrachloroethene to Ethene, 276 Science 1568-1571 (1997). Real-time quantitative polymerase chain reaction with DHE-specific primers allowed for the detection of desired gene copies to less than two gene copies per milliliter.
Baseline sampling at the site did not indicate the presence of DHE in groundwater. The absence of DHE in baseline samples was not unexpected given that the conditions within the aquifer were aerobic/mildly reducing, generally not hospitable for the DHE organism. It was thought that the onset of lactate injection and the subsequent depletion of terminal electron acceptors would create an environment more hospitable for DHE and allow the organism to increase in abundance, if present.
There are two possibilities to explain the lack of significant ARD past reduction of TCE to cis-DCE to date. First, it is possible that insufficient time has passed for ARD of cis-DCE to occur. Second, it is possible that the organisms required for complete ARD to ethene are not present at this site. If this second possibility is the explanation for lack of complete ARD, bioaugmentation may be required to achieve complete ARD to ethene at this site.
Conclusions. Nine months of monitoring during lactate injection in a large-scale, mildly reducing aquifer achieved the following results. First, the injection system successfully delivered significant quantities of an electron donor throughout the treatment area. Second, methanogenic conditions were achieved throughout the treatment area. Third, stoichiometric anaerobic reductive dechlorination to cis-DCE was observed throughout the treatment area. Fourth, baseline DNA screening indicated the absence of Dehalococcoides ethenogenes in groundwater prior to electron donor injection at the site. Fifth, the absence of advanced anaerobic reductive dechlorination beyond cis-DCE may be the result of insufficient time for biomass growth or may be due to the absence of the organisms required for advanced anaerobic reductive dechlorination.
A biostimulation pilot-test program for in situ anaerobic bioremediation of chlorinated ethenes in groundwater was conducted at Installation Restoration (IR) Program Site 40, Naval Weapons Station Seal Beach, Calif. IR Site 40 includes a concrete pit in a locomotive shop building and a gravel area north of and adjacent to the building. Oil and solvents spilled during locomotive maintenance collected in the pit and discharged to the gravel area via a drainpipe (
The geologic units observed at IR Site 40 include three sand units at shallow depths. The interval selected for pilot-testing, known as the "second sand unit," comprised saturated sands to silty sands. Slug testing during previous investigations indicated that hydraulic conductivities in this unit were typical of unconsolidated silty sands to sands (R. A. Freeze J. A. Cherry, Groundwater (Prentice Hall, Inc. 1979)).
Natural anaerobic biodegradation was occurring, but the process was slow, and it was believed that it could be accelerated by enhancing biological activity by the addition of an electron donor to the groundwater.
The tests were conducted in the area interpreted to have the highest PCE concentrations in groundwater. The tests were conducted over an 8-month period from August 2001 through mid-March 2002. Approximately 210,000 liters (55,500 gallons) of 3 percent sodium lactate solution was injected. A direct injection system was selected over recirculation to avoid reinjection of untreated water into the test cell. A 60 percent sodium lactate solution (JRW Technologies, Lenexa, Kans.) was diluted to 3 percent with potable water using a proportional injector (Dosatron International, Bordeaux, France). Lactate was injected at an average rate of approximately 3,550 gallons per week for the first 2 months. The average injection rate was then adjusted to approximately 750 gallons per week to maintain optimum electron-donor concentrations. No clogging or fouling effects were observed over the course of the pilot test. Water level measurements were performed during injection to assess the induced gradient.
Effects were monitored in seven wells in the pilot-test area. Two wells are located crossgradient and five downgradient of the injection well at distances ranging from approximately 2 to 30 m. Pretest groundwater samples were collected to establish baseline conditions. Weekly groundwater samples were collected during and analyzed on-site using field test kits for sulfate, ferrous iron, alkalinity, chemical oxygen demand (COD) (Hach, Loveland, Colo.), nitrate, and carbon dioxide (CHEMetrics, Calverton, Va.) and direct reading instrumentation for pH, temperature, conductivity, oxidation-reduction potential, and dissolved oxygen (YSI, Yellow Springs, Ohio). Monthly groundwater samples were analyzed off-site for volatile organic compounds, alkalinity, COD, anions, cations, total dissolved solids (Columbia Analytical Services, Kelso, Wash.), and dissolved gases (Performance Analytical, Simi Valley, Calif.). Samples were periodically analyzed for organic acids (Idaho National Engineering and Environmental Laboratory [INEEL], Idaho Falls, Id.), phospholipid fatty acids (Microbial Insights, Rockford, Tenn.), and DNA typing using quantitative polymerase chain reaction (PCR) and terminal restriction fragment length polymorphisms (T-RFLP) analyses (University of California, Berkeley, Calif.), according to methods well known in the art.
Test results indicated that biological activity was stimulated in the pilot test area.
Favorable redox conditions were created for reductive dechlorination (
Reductive dechlorination correlated closely with sulfate reduction and methanogenesis (
Bacterial DNA characterization with D. ethenogenes specific primers indicated that this species of bacteria known to be capable of complete dechlorination from PCE to ethene was not present at IR Site 40. Real-time quantitative PCR allowed for the detection of desired gene copies to very low numbers (in this case, less than two gene copies per milliliter).
Water level measurements indicated that lactate injection produced a radial mounding effect in the aquifer during injection periods, with no appreciable influence by the relatively flat regional groundwater gradient. The radius of influence within which PCE was converted to DCE was approximately 6 m crossgradient and 8 m downgradient.
Partial dechlorination of PCE to DCE, as evidenced in this pilot test, is anticipated to accelerate the overall natural attenuation processes in the aquifer at IR Site 40. Lactate enhancement resulted in stimulation of biological activity and creation of appropriate redox conditions for complete reductive dechlorination. Bacterial DNA test results indicated that the most likely cause for incomplete dechlorination is that an appropriate microbial consortium for complete reductive dechlorination is not present at the site.
Bioaugmentation at this site by injecting a microbial culture containing D. ethenogenes later facilitated complete dechlorination at the site (J. H. French et al., Phased In Situ Biostimulation/Bioaugmentation Pilot Results from a Coastal Aquifer, Fourth Int'l Conference on Remediation of Chlorinated and Recalcitrant Compounds, Monterey, Calif. (2004). Sodium lactate was also injected to maintain electron donor concentrations appropriate for reductive dechlorination. Groundwater monitoring was conducted for approximately 6 months. Moreover, DNA testing using quantitative PCR and T-RFLP was used to track the survival and proliferation of the injected microbes.
This example shows that PCE concentrations increased greater than fifteen-fold in at least one well following injection of electron donor. No residual source areas were present at this site, thus desorption of sorbed phase contamination in dissolved plume areas was believed responsible for the observed increase in PCE concentrations. This suggests that desorption of sorbed phase contamination is a key enhanced transfer mechanism, promoted by addition of electron donor, in dissolved plume areas.
|Cited Patent
|Filing date
|Publication date
|May 25, 1984
|Apr 29, 1986
|Southern Research Institute
|Long-acting biocidal compositions and method therefor
|Nov 24, 1992
|Nov 23, 1993
|Plant Research Laboratories Inc.
|Use of metallic peroxides in biormediation
|May 4, 1992
|Jan 11, 1994
|E. I. Du Pont De Nemours And Company
|In situ biodegradation of groundwater contaminants
|Jan 14, 1993
|Mar 7, 1995
|Plant Research Laboratories
|Therapeutic and preventative treatment of anaerobic plant and soil conditions
|Dec 22, 1993
|Jul 18, 1995
|Korea Institute Of Science And Technology
|Biodegradable poly(lactic acid)s having improved physical properties and process for their preparation
|Apr 28, 1994
|Oct 17, 1995
|Samsung General Chemicals Co., Ltd.
|Highly active catalyst for the polymerization of olefins and method for the preparation of the same
|Apr 29, 1994
|Nov 7, 1995
|The United States Of America As Represented By The Secretary Of Agriculture
|Biologically pure culture of Actinomyces viscosus strain used for the bioremediation of chlorinated hydrocarbons
|Oct 7, 1994
|May 14, 1996
|Envirogen, Inc.
|Method of biodegrading hydrophobic organic compounds, particularly PCBS, and remediation thereof using a bioemulsifier
|Apr 13, 1995
|Oct 1, 1996
|Cosmetic and/or dermatological composition containing a glyceryl tri(.alpha.
|Nov 27, 1995
|Dec 24, 1996
|E. I. Du Pont De Memours & Company
|Chemical-biological process for dehalogenation of halogenated organic compounds
|Jun 7, 1995
|Feb 11, 1997
|Board Of Trustees Operating Michigan State University
|Method and compositions for remediation
|Dec 13, 1995
|Aug 19, 1997
|Canon Kabushiki Kaisha
|Method for biodegradation of polluting substance
|Nov 6, 1995
|Jul 21, 1998
|Battelle Memorial Institute
|Method of removing oxidized contaminants from water
|Aug 22, 1996
|Nov 10, 1998
|Auburn University
|Situ bioremediation of contaminated groundwater
|Dec 12, 1995
|Nov 24, 1998
|E. I. Du Pont De Nemours And Company
|Biological degradation of halogenated components in the unsaturated soil zone
|Mar 6, 1997
|Aug 3, 1999
|Twin Oaks Envirormental Ltd.
|Method for degradation of polychlorinated biphenyls in soil
|Sep 24, 1996
|Nov 30, 1999
|Canon Kabushiki Kaisha
|Method for biodegrading trichloroethylene and method for biodegrading chlorinated organic compound by microorganisms
|Jul 9, 1998
|Dec 14, 1999
|Rmt, Inc.
|In situ anaerobic dehalogenation
|Jan 27, 1998
|Jul 24, 2001
|Lynntech, Inc.
|Enhancement of soil and groundwater remediation
|Nov 12, 1998
|Jul 16, 2002
|Regenesis Bioremediation Products
|Polylactate release compounds and methods of using same
|May 14, 1999
|Oct 29, 2002
|The State Of Oregon Acting By And Through The State Board Of Higher Education On Behalf Of Oregon State University
|Slow release substrates for driving microbial transformations of environmental contaminants
|Aug 8, 2000
|May 13, 2003
|Groundwater Services, Inc.
|Enhanced anaerobic treatment zones in groundwater
|Oct 24, 2000
|Jul 8, 2003
|General Electric Company
|Method for treating contaminated media
|Jun 29, 2001
|Aug 31, 2004
|Bechtel Bwxt Idaho, Llc
|Halogenated solvent remediation
|Aug 20, 2003
|May 16, 2006
|Srp Technologies, Inc.
|Electron donors for chlorinated solvent source area bioremediation
|Feb 27, 2001
|Sep 27, 2001
|Perriello Felix Anthony
|Method and apparatus for anaerobically degrading pollutants with alkanes
|Nov 30, 1999
|Feb 7, 2002
|Michael Jarlath Brennan
|Bioremediation of halogenated hydrocarbons by inoculation with a dehalogenating microbial consortium
|Jun 29, 2001
|Feb 21, 2002
|Bechtel Bwxt Idaho, Llc
|Halogenated solvent remediation
|Nov 12, 1998
|May 20, 1999
|Regenesis Bioremediation Products
|Polylactate release compounds and methods of using same
|Bouwer, et al. "Transformations of 1- and 2- Carbon Halogenated Aliphatic Organic Compounds Under Methanogenic Conditions," Applied and Environmental Microbiology, Apr. 1983 pp. 1286-1294.
|Carr, et al., "Effect of Dechlorinating Bacteria on the Longevity and Composition of PCT-Containing Nonaqueous Phase Liquids under Equilibrium Dissolution Conditions," Environmental Science & Technology, vol. 34, No. 6, 2000 pp. 1088-1094.
|Distefano, et al., "Hydrogen as an Electron Donor for Dechlorination of Tetrachloroethene by an Anaerobic Mixed Culture," Applied and Environmental Microbiology, Nov. 1992 pp. 3622-3629.
|Distefano, et al., "Reductive Dechlorination of High Concentration of Tetrachloroethene to Ethene by an Anerobic Enrichment Culture in the Absence of Methanogenesis," Applied and Environmental Microbiology, Aug. 1991 pp. 2287-2292.
|Fennell, et al., "Comparison of Butyric Acid, Lactic Acid, and Propionic Acid as Hydrogen Donors for the Reductive Dechlorination of Tetrachloroethene," Environmental Science & Technology, vol. 31, No. 3, 1997 pp. 918-926.
|Fennell, et al., "Modeling the Production of an Competition for Hydrogen in a Dechlorinating Culture," Environmental Science & Technology, vol. 32, No. 16, 1998 pp. 2450-2460.
|Freedman, et al., "Biological Reductive Dechlorination of Tetrachloroethylene and Trichloroethylene to Ethylene under Methanogenic Conditions," Applied and Environmental Microbiology, Sep. 1989 pp. 2144-2151.
|Holliger, et al., "A Highly Purified Enrichment Culture Couples the Reductive Dechlorination of Tetrachloroethene to Growth," Applied and Environmental Microbiology, Sep. 1993 pp. 2991-2997.
|Howze, "Test at Tan Bioremediation of Groundwater Plume Shows Promise," iNEWS, Jul. 6, 1999.
|Maymo-Gatell, et al, "Isolation of a Bacterium That Reductively Dechlorinates Tetrachoroethene to Ethene," Sicence, vol. 276, pp. 1568-1571, (1997).
|McCray, et al., "Cyclodextrin-Enhanced Solubilization of Organic Contaminants with Implications for Aquifer Remedication," Winter 2000 GWMR, pp. 94-103.
|Sorenson, K.S., "Intrinsic and Enhanced In Situ Biodegradation of Trichloroethene in Deep, Fractured Basalt Aquifer," Dissertation, May 2000.
|Vogel, et al., "Biotransformation of Tetrachloroethylene to Trichloroethylene, Dichloroethylene, Vinyl Chloride, and Carbon Dioxide under Methanogenic Conditions," Applied and Environmental Microbiology, May 1985 pp. 1080-1083.
|Citing Patent
|Filing date
|Publication date
|Jul 22, 2010
|Clemson University
|Development of a Fermentative Enrichment Culture and Two Pure Isolates that Biotransform High Concentrations of Chloroform and Other Halomethanes
|U.S. Classification
|210/610, 435/262.5, 210/757
|International Classification
|Cooperative Classification
|European Classification
|Oct 6, 2008
Owner name: SRP TECHNOLOGIES, INC., COLORADO
Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:SORENSON, KENT S., JR.;REEL/FRAME:021638/0813
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text:
From Wikipedia, the free encyclopedia
|Look up homing in Wiktionary, the free dictionary.
Homing is the process of determining the location of something, sometimes the source of a transmission, and going to it.
More specifically, it may refer to:
- Guidance system, a device or group of devices used to navigate a ship, aircraft, missile, rocket, satellite, or other craft
- Homing (missile guidance)
- Infrared homing, a passive missile guidance system which uses the emission from a target of infrared electromagnetic radiation
- Semi-active radar homing, a common type of missile guidance system for longer-range air-to-air and surface-to-air missile systems
- Active radar homing, a missile guidance method in which a guided missile uses a radar transceiver to find and track its target autonomously
- Homing torpedo, "fire and forget" torpedoes can using passive or active guidance
- Homing (missile guidance)
- Acoustic homing, a system which uses sound to guide a moving object
- Homing (biology), the inherent ability of an animal to navigate towards an original location through unfamiliar areas
- Homing pigeon, a variety of domestic pigeon bred to find its way home over extremely long distances
- Homing beacon, sometimes homer, a beacon that transmits a signal to be homed on
Homing may also refer to:
- Multiple homing, two types of telephone connections of a terminal facility
- Homing (hematopoietic), a process of cellular migration
See also[edit]
|This disambiguation page lists articles associated with the title Homing.
If an internal link led you here, you may wish to change the link to point directly to the intended article.

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It is the iconic image of Brazil, one you've probably seen hundreds of times and likely will hundreds more over the coming weeks as NBC presents 6,755 hours of television and digital coverage of the 2016 Summer Olympics from Rio de Janeiro.
Follow our live coverage of Mike McCarthy's early morning news conference and the Packers' training camp practice. McCarthy speaks at 7:45 and players take to Ray Nitschke Field at 8:15 Saturday morning.
CNNPGA Championship: McIlroy left frustrated by 'pathetic' puttingCNN(CNN) Rory McIlroy didn't hold back when asked by reporters where it all went wrong after he missed the cut at the PGA Championship. The Northern Irishman and four-time major winner bogeyed the last at Baltusrol Golf Club in New Jersey to card a and more »
Phil Mickelson walked off the first green with a disgusted look on his face, as if he'd thrown away any shot at making the cut in the PGA Championship.


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Neo-Tokyo 2019. The city is well on the way to rebuilding after World War III. The central characters Kaneda and Tetsuo two high school drop-outs are members of a joy-riding motorcycle gang. In the opening scene Kaneda and Tetsuo stumble upon a secret government project to develop telekinetic humans apparently for use as weapons. Tetsuo learns of the existence of his peer Akira the projects most powerful subject and determines to challenge him...Check stock and price
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Sun, Aug 7 | 11 a.m.
A plucky young girl finds and befriends a small dog, despite local superstitions and her father's objections.
Free admission!
Through Aug 12
The Archive looks back at the Spanish Civil War 80 years later, presenting a diversity of genres and eras, from newsreels to features produced in Spain and Hollywood.
Through Sept 30
A tribute to legendary actor Kirk Douglas, who has enlivened American cinema with his portrayals of embattled and relatable individuals.
Jul 22 - Aug 6
French director Pialat forged a fiercely independent path for himself, eschewing lessons in morality in favor of raw, intensely personal reality.
Sat, Aug 13 | 7:30 p.m.
An ultra-rare double feature of two film noir classics, Leave Her to Heaven (1945) and Nightmare Alley (1947), presented in original 35mm nitrate prints!
To report problems, broken links, or comment on the website, please contact support
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Mad Bastards film soundtrack features this week
105.7 ABC Darwin and 783 Alice Springs new feature album of the week sees three Australian musicians teaming up for a Mad Bastards film soundtrack inspired by the landscape of Kimberley region
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Who are the Mad Bastards Trio?
Only three of Australia's most interesting musicians, teaming up together to compose the soundtrack to the new Australian feature film, Mad Bastards.
In what would other otherwise seem like an unlikely collaboration, hit-maker Alex Lloyd and Broome stalwarts, Alan and Stephen Pigram - have joined forces to create a moving soundtrack for Brendan Fletcher's movie.
The Mad Bastards Trio got together in the Kimberley region, where the film is set, and spent time together writing music, letting the landscape and film's narrative drive the song writing process.
Writing around the camp-fire, and on-set, the tracks chosen for the album reflect the natural camaraderie the musicians shared while working together, something that's seen them tour the country together, bringing The Mad Bastards Trio to most capital cities around the country.
On the Mad Bastards Soundtrack, Alex Lloyd gets down with bluesy bad self, and Stephan and Alan Pigram bring their trademark tropical charm to the mix - a collaboration that's enriching.
The Mad Bastards Soundtrack is our Album of the Week.
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— —
X-MAS IN JULY, 15096, Lyndhurst oh
This will be our 5th appearance at this storied event. It is by invitation only so GET ONE!
After 30 years, Thousands of miles, Hundreds of gallons of whisky
"POPPA"D" AND THE AGGRAVATORS have established themselves as the keeper of the flame of MODERN BLUES. The Common barriers facing a band of musicians doing the unconventional have been removed. What is left is a Fun,Zesty Music we call D - BLUES! Forget what you know about Blues Bands. We take elements from other popular Musical platforms to create a fresh approach. So there are no more excuses to not LOVE THE BLUES! This website is designed to keep you on the cutting edge of all things "D"! We will post concert dates, new videos and give you the chance to grab the latest sounds and fashions generated by the Aggravators!
Feel free to contact us anytime . You can request a Booking, suggest a venue or just say HI! so, strap in and come back often. We update daily. Greetings from POPPA "D" AND THE AGGRAVATORS, Sit back and ENJOY THE WEBSITE!
We Thank You….
Poppa D And The Aggravators
Have Won an International Music Award!
The Akademia Music Award for Best Blues Song for 'I Face My Troubles Alone' in the January 2016 Akademia Music Awards! VIEW OUR AWARD PAGE!
— —
X-MAS IN JULY, 15096, Lyndhurst oh
This will be our 5th appearance at this storied event. It is by invitation only so GET ONE!
Poppa "D"And The Aggravators
— —
Back at Edison's Pub one last time before we record TWISTED CITY!
— —
The Old Firehouse Winery , 5499 Lake Rd, Geneva-on-the-Lake, OH 44041
Come out to Geneva-on-the-Lake , August 20 from Noon to Midnight for Beer, Burgers and Blues — featuring music by Poppa D And the Aggravators and TWO Other Off the Chain blues Artists to be announced.Great food and some awesome microbrews to try too! We've got a stellar exhibitor line-up this weekend so plan to join us at the Old Firehouse Winery, 5499 Lake Road East, Geneva-on-the-Lake, OH 44041. Admission is FREE! See you in GOTL!
— —
It's September! Just Party!
CBS September Blues Jam
La Taqueria , 5115 Wilson Mills Rd., Suite 2, Richmond hts. Ohio 44143
No matter your skill or age you are welcome to jam with the some of best Blues Musicians in Northeast Ohio. Just bring your instrument or sticks and get on up!


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FREE SMOKE DETECTORS, INSTALLATION offered through program
The American Red Cross has joined forces with City Councilman Alex Garza and the T
NEW FEE SCHEDULE in place to penalize for excessive false alarms in community
Last year, Taylor Police and Fire had to respond to more than 2,000 false alarms in the community.
SAFETY TOWN returns for 2016! Sign up now
Safety Town 2016, brought to you to the Taylor Police Department, is scheduled for mor
ROBERT DICKERSON NAMED City's Chief of Staff
POSTED: April 26, 2016


text: Review Comprehensive Control of Atomic Motion Mark G. RaizenCenter for Nonlinear Dynamics and Department of Physics, The University of Texas at Austin, Austin, TX 78712, USA. E-mail: raizen{at}physics.utexas.edu Science 12 Jun 2009:Vol. 324, Issue 5933, pp. 1403-1406DOI: 10.1126/science.1171506 Mark G. RaizenFind this author on Google Scholar Find this author on PubMed Search for this author on this site Article Figures & Data Info & Metrics eLetters PDF Log in to view full text Username Enter your Sciencemag.org username. Password Enter the password that accompanies your username. Forgot your username or password?Log in Join/Subscribe Purchase Article Activate Member Account Renew Subscription Recommend a subscription to your library Help for librarians


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To be creepy in a sorta a terrific way.
Bob said I looked pretty in my new sweater, as he was licking his lips and scratching his balls...Creeparific
di Shanny P 12 dicembre 2007
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The Old Lady regains her roar
Ciaran Kelly discusses the resurgence of Juventus in Serie A.
Ciaran Kelly discusses the resurgence of Juventus in Serie A.
Ciaran Kelly believes that Roberto Di Matteo has done an excellent job at Chelsea since taking the reins.
Ciaran Kelly looks at how a crazy Italian has made a League One side his home.
The second part of Ciaran Kelly's look at the life and times of José Mourinho.
Ciaran Kelly takes an in depth look at the Special One, José Mourinho.
Back Page Football's UEFA Champions League correspondent Ger McCarthy looks back at the another week of last-sixteen first leg fixtures and makes some bold predictions about how each of the return games will go as we reach the business end of the competition.
Ciaran Kelly shares his thoughts on the decision by Paris St Germain to install Carlo Ancelotti as their new boss.
Ciaran Kelly looks at the Italian national team and believes that they are a better side than most people give them credit for.
Scott Parker has been drawing a lot of praise for his recent Spurs performances and Ciaran Kelly looks at the midfielder's career to date.
Ciaran Kelly looks at the weird and wonderful career of former Lazio and England boss Sven-Göran Eriksson.


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Homewood Suites By Hilton Oxnard/Camarillo
Homewood Suites By Hilton Oxnard/Camarillo
Hotel Guest Rating: 9.0/10
1950 Solar Drive
Oxnard, CA 93036
Hotel Freebies Available*
• On Sale Now -> Save 15% on select dates show dates
• Save $17 per night on select dates show dates
• Save $11 per night on select dates show dates
• Free Breakfast show dates
• Free Internet in Room show dates
• Free Parking show dates
Welcome to the Homewood Suites By Hilton Oxnard/Camarillo
Modern and elegant, Homewood Suites by Hilton Oxnard/Camarillo welcomes Priceline guests with free breakfast, an outdoor pool, and suites featuring flat-panel TVs and full kitchens.
Hotel Features
All 129 suites at the mid-rise Homewood offer sofa beds, work desks, flat-panel TVs, premium cable channels, high-speed internet access, luxury toiletries and full kitchens with granite countertops. Kick-start your day here at the complimentary breakfast. Guests with work in tow catch up in the 24-hour business center before heading to the outdoor pool and a hot tub. To keep in tip-top shape, visit the fitness room. For added fun, shoot hoops at the basketball court. Guest laundry is available. Parking is free.
Hotel Location
The Homewood is two blocks from Highway 101 and Saint John's Regional Medical Center. Local beaches are about six miles away, and the Camarillo Premium Outlets are 10 miles east. Not to be missed: you can watch whales swim into the sunset at Port Huenene Beach Park and Fishing Pier, nine miles from the hotel. Naval Base Ventura County Point Mugu is 10 miles away. Bob Hope Airport in Burbank is 52 miles east.
Guest Favorites
Priceline guests can expect full kitchens, an outdoor pool, staff that go "above and beyond" and easy access to area attractions at the "luxurious" Homewood Suites by Hilton Oxnard/Camarillo.
Homewood Suites By Hilton Oxnard/Camarillo Amenities
- Air conditioning
- Air conditioning individually controlled in room
- Alarm clock
- Buffet breakfast
- Business center
- Cable television
- Child programs
- CNN available
- Cocktail lounge
- Complimentary buffet breakfast
- Complimentary cocktails
- Complimentary coffee in lobby
- Complimentary in-room coffee or tea
- Conference facilities
- Desk with electrical outlet
- Direct dial telephone
- Evening reception
- Exercise gym
- Express check-in
- Express check-out
- Family plan
- Fire safety compliant
- Fitness center on-site
- Free high speed internet connection
- Free parking
- Grocery shopping service available
- Hairdryer
- Heated guest rooms
- Heated pool
- High speed internet access fee
- Interior corridors
- Iron
- Ironing board
- Jacuzzi
- Kitchenette
- Late check-out available
- Laundry/Valet service
- Lobby coffee service
- Meeting rooms
- Non-smoking
- Non-smoking rooms (generic)
- On-site business center
- On-site business center is staffed
- On-Site parking
- Outdoor pool
- Parking
- Parking lot
- Photocopy center
- Pool
- Public address system
- Public area air conditioned
- Remote control television
- Safe deposit box
- Security
- Valet cleaning
- Voice mail
- Welcome drink
- Whirlpool
Hotel Information
Upon check-in photo identification and credit card is required. All special requests are subject to availability upon check-in. Special requests cannot be guaranteed and may incur additional charges. Guests are required to show a photo identification and credit card upon check-in. Please note that all Special Requests are subject to availability and additional charges may apply.
Hotel Guest Reviews of the Homewood Suites By Hilton Oxnard/CamarilloOur hotel ratings and reviews are from real hotel guests. Priceline.com ensures that its reviews are guests-only by proactively sending hotel surveys to customers after they've completed their hotel stays. In the post-stay surveys, priceline.com hotel customers are asked a number of questions about their stay and the hotel. On a scale of 1-10 with 10 being the best, the survey asks guests to rate their overall experience and specifically rate the hotel's cleanliness, staff and location. Priceline.com does not allow site visitors to post unsolicited hotel reviews.
Sort by: All Travelers | Business Traveler(3) | Solo Traveler(1) | Traveling as Couple(8) | Family with Young Children(1) | Group Traveler(2)
Verified Hotel Guest from San Jose, CA
June 28, 2016
June 28, 2016
Nice accommodations and staff. Breakfast was pretty good also.
Salvador from Porter, TX
May 17, 2016
May 17, 2016
Clean place safe area frenly personal good breakfast
Not evertyning was perfet
Cedric from San Diego, CA
April 25, 2016
April 25, 2016
The conciere allowed us to check in 2 hours early! Cleanlinesss,location is readily accessible to various local stores and venues. The complimentary breakfast was nice and edible.
The Homewood is a nice stay. Our neighbors above us had some heavy feet. :-) nothing major
Reanne-Alysone from Daly City, CA
April 12, 2016
April 12, 2016
The hotel staff were very welcoming. The hotel was right off the freeway and a shopping center was nearby.
I would have preferred to have a room on a higher floor, but it was ok. Another thing was that the hallway doors were oddly centered. It wasn't a huge problem, but normally I'm used to hotels that have a long hallway that's not separated by a few doors.
Verified Hotel Guest from Encinitas, CA
December 9, 2015
Business Traveler
December 9, 2015
Business Traveler
Customer service was very helpful. The venue next door to the hotel had an event and the parking lot filled up. Lewis at the front desk allowed me to park my car in front of the entrance over night.
Some of the people at the front desk are not as pleasant as others.
Verified Hotel Guest from Canoga Park, CA
September 29, 2015
Family Traveling with Young Children
September 29, 2015
Family Traveling with Young Children
We just love everything about this hotel and will definitely come back!
Verified Hotel Guest from Carlsbad, CA
September 14, 2015
Group Traveler
September 14, 2015
Group Traveler
Large suite area with kitchenette
the location is average
Titinia from Oxnard, CA
August 25, 2015
August 25, 2015
New facility
Key card had to be replaced twice, chair in room was torn, and I have yet to receive a refund of my comp deposit of $ 200.00.
Ron from Anaheim, CA
June 28, 2015
Business Traveler
June 28, 2015
Business Traveler
My king room was just amazing loved it !
Decor, size , kitchen, bathroom, shower size !! Perfect!
Verified Hotel Guest from Fillmore, CA
March 27, 2015
March 27, 2015
The location, cleanliness and excellent service.
Reviews of Homewood Suites By Hilton Oxnard/Camarillo
(1 - 10 of 15 reviews)
(1 - 10 of 15 reviews)
from $151
- Hilton Garden Inn Oxnard/Camarillo from $249 (0mi)
- Grandstay Residential Suites Oxnard (0.1mi)
- Courtyard Oxnard Ventura from $154 (1.8mi)
- Vagabond Inn Oxnard from $74 (1.9mi)
- Flamingo Motel Oxnard from $69 (2.1mi)
- Outback Steakhouse (0.4mi)
- Tierra Sur at Herzog Wine Cellars (1.3mi)
- Baja Fresh Mexican Grill (1.9mi)
- Du-par's (1.9mi)
- In-N-Out Burger (2.2mi)
- Port Hueneme, CA (4.6 mi)
- Camarillo, CA (10.7 mi)
- Ventura, CA (11.2 mi)
- Santa Paula, CA (16.5 mi)
- Newbury Park, CA (19.4 mi)
- Oak View, CA (20.9 mi)
- Thousand Oaks, CA (24.8 mi)
- Ojai, CA (26.7 mi)
- Fillmore, CA (26.9 mi)
- Westlake Village, CA (26.9 mi)
- Agoura Hills, CA (29.7 mi)
- Simi Valley, CA (29.9 mi)
- Carpinteria, CA (29.9 mi)
Most Popular Guest-Rated Hotels in Oxnard
Most Popular Business-Friendly Hotels in Oxnard
- Residence Inn Oxnard River Ridge
- Grandstay Residential Suites Oxnard
- Homewood Suites By Hilton Oxnard/Camarillo
Most Popular Romantic Hotels in Oxnard
- Embassy Suites Mandalay Beach Hotel & Resort
- Homewood Suites By Hilton Oxnard/Camarillo
- Hampton Inn Channel Islands Harbor
Most Popular Family-Friendly Hotels in Oxnard
- Embassy Suites Mandalay Beach Hotel & Resort
- Residence Inn Oxnard River Ridge
- Homewood Suites By Hilton Oxnard/Camarillo


text:
- 익명
- 캐나다, 여성, 25-30
- 열혈 여행자
- 14 이용후기
The location was great and good value for money. The staff were super friendly and spoke decent English. The wifi was good, hot showers, huge common area, and they offered storage for when you want to go hiking. The things we didn't like were some of the in room lockers were broken, there was mold on the wall, and clearly the beds haven't been cleaned as there was stuff on my bed when I arrived. Otherwise, overall good experience.
- 익명
- 네덜란드, 남성, 18-24
- 초보 여행자
- 4 이용후기
Great hostel! Cozy hostel. The staff is very friendly, and can speak English. When i was arrived on the AirPort in Lijiang for my flight to Shanghai, did i lost my wallet. I did call the reception from this hostel and they found my wallet! But it was to short time for them to bring my wallet to the AirPort before my flight. But they were very friendly! They did help me with this problem very well by mail. They send my wallet to my hotel in Shanghai and 2 days later, i had my wallet! Thankyou!
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호스텔월드 모바일앱으로 예약하세요.


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The O-P-P are investigating a deadly crash this morning near Caledonia. They say two people were killed when a tractor-trailer collided with a pickup truck on Highway 6. The highway could remain closed from Argyle Street south to Fourth Line for several hours as police investigate the cause of the accident. The identities if the victims have not yet been released.
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American Songwriter is the perfect place to release new music from Colorado's celebrated band Paper Bird. The site premiered "I Don't Mind" from the band's new release PAPER BIRD, which hits September 9 on Thirty Tigers.
You could say Brian Langlinais' new recording, Right Hand Road, was birthed by an ice storm, but that would be getting ahead of the story
The 7th annual Highberry Music Festival took place this weekend after its trek up Mulberry Mountain from years prior at Byrds Adventure Center. Art, camping and a spectacular lineup brought patrons from all over the country to enjoy the gorgeous Arkansas scenery and the best company that has ever assembled on a mountain top. Minimal weather events kept the air cool while musicians the likes of Buckethead, Keller Williams, Wookiefoot and Yonde
The official music video for "Priceless" from Canadian electronic musicians MSTRKRFT made its premiere today, July 6, on
Hard Working Americans have announced opening acts ahead of its 2016 tour in support of the new album, Rest In Chaos. The dates will see The Mother Hips in 4 west coast cities, Aaron Lee Tasjan in Texas and Arkansas, Raelyn Nelson Band in Birmingham and Atlanta, and The Congress in Knoxville, Charlotte, Wilmington and Saxapahaw. A limited number of tickets for all shows remain.
After a newly formed partnership, The Rex Foundation and the Jake Peavy Foundation announced today their first benefit concert: Can't Stop The Train––A Tribute to Jerry Garcia, taking place Wednesday, August 17, 2016 at 9 p.m. at the Fillmore. The lineup features: Jackie Greene, Col.
Colorado based Americana Quintet The Drunken Hearts hosted their "Love & Thirst" album release party on a Thursday night at the Bluebird Theater in Denver. A far cry from the soulless popular music seeding festivals and stadiums, The Drunken Hearts played an intimate and emotional set.
Greener Grounds has been busy on the festival circuit, heavy touring, a new album "Momentous" as well as an even more touring supporting your new album.
With Dead and Company playing the first concerts in 15 years at CU's Folsom Field this weekend we wanted to give folks some ideas what else to do in Boulder before and after the show(s).
Go hiking! Yes – if you're coming to Boulder for the first time, we have some of the best hiking trails in our backyard. Some suggestions depending on your fitness level:
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