WO2021096529A1 - Method of capturing an organofluorine - Google Patents

Abstract

The present invention resides in a method of capturing an organofluorine from a liquid. The method includes the steps of contacting the liquid comprising the organofluorine with a sorbent to form an organofluorine sorbed material, and contacting the organofluorine sorbed material with one or more binders to form an organofluorine captured material.

Description

TITLE

METHOD OF CAPTURING AN ORGANOFLUORINE

FIELD OF THE INVENTION [001] The present invention relates to the field of purification. More particularly, the invention relates to a method of capturing an organofluorine.

BACKGROUND TO THE INVENTION

[002] It will be clearly understood that, if a prior art publication is referred to herein, this reference does not constitute an admission that the publication forms part of the common general knowledge in the art in Australia or in any other country.

[003] Organofluorines (compounds which include a C-F bond), and especially alkylfluorines, are produced industrially for a wide range of applications, including as surfactants, polymers (such as Teflon™), firefighting foams, and in medicinal and agricultural products. However, alkyl C-F bonds are very strong, and are typically extremely stable, being resistant to hydrolysis, photolysis, microbial degradation and metabolism by vertebrates. Whilst fluorine is very electronegative, when a carbon atom is substituted by many fluorine atoms (such as in perfluoroalkyl compounds) the dipole moment of each C-F bond can cancel each other, and can result in a relatively non-polar (and non-reactive) compound. Furthermore, the fluorine in an alkyl C-F bond can sterically shield the carbon atom to which it is attached, and the three pairs of non bonding electrons in fluorine’s outer electronic shell can also protect the C-F bond, further improving the stability of alkylfluorines. C-F bonds are not common in nature, and consequently there are few biological pathways to break down alkyl C-F bonds. Consequently, alkylfluorines are often very stable and have a half-life spanning decades. It can be very difficult to degrade such alkylfluorines, or to separate them from liquids including water.

[004] Due to extensive use, organofluorines, and especially per- and polyfluoroalkyl substances (PFASs), are frequently found in groundwater, landfill leachates, and industrial wastes. PFASs have accordingly attracted increasing attention as emerging contaminants of global concern.

[005] For example, a 2016 study covering two-thirds of drinking water supplies in the United States found levels of fluorosurfactants above safe drinking water guidelines in 194 out of 4,864 water supplies in thirty three (33) U.S. states, with thirteen (13) states accounting for almost 75% of the detections (Hu, X.C. et al. (2016) Environ. Sci. Technol. Lett., 3(10), 344-350). Firefighting foam was singled out as a major contributor. Sixty-six of the public water supplies examined, serving six million people, had at least one water sample that measured at or above the EPA safety limit of 70 parts per trillion (ng/L) for two types of PFASs, perfluorooctanesulfonic acid (PFOS) and perfluorooctanoic acid (PFOA). Concentrations ranged as high as 349 ng/L for PFOA (Warminster, PA) and 1,800 ng/L for PFOS (Newark, DE).

[006] Discharge of effluents from municipal wastewater treatment plants is a primary route for the introduction of refractory and persistent organic contaminants into marine and freshwater aquatic environments. Earlier studies have reported the occurrence of perfluorinated compounds (PFCs) in effluents from wastewater treatment plants. Common examples of these PFCs include Perfluorobutane sulfonate (PFBS), PFHxS (Perfluorohexane sulfonate), PFOS (Peril uorooctane sulfonate), Perfluorobutanoate (PFBA) and Perfluorooctanoate (PFOA).

[007] PFOS also results from the chemical or metabolic hydrolysis of some fluorosurfactants and can form salts with monovalent metallic cations, many of which appear to be resistant to further degradation under normally occurring environmental conditions. This leaves PFOS as the ultimate degradation product from many fluorochemicals and it will generally persist in that form. Unfortunately, PFOS is known to be both toxic, (affecting hormonal metabolism and reproduction in test species) and bio-accumulative (showing biomagnification in the food chain). PFOS is also so chemically stable that it is able to withstand hot nitric or sulphuric acid for 24 hours without decomposition.

[008] PFOA is a similar surfactant widely associated with fluorocarbon manufacture and firefighting foams. The strength and characteristics of the carbon- fluorine bond insures that the molecule once formed is relatively inert and persists in the environment for long periods. The detrimental health effects of PFOA have been widely documented and there has been an increasing need to remove this chemical from ground water sources.

[009] Presently organofluorines contaminants are isolated and incinerated at high temperatures. However, this can lead to the formation of other perfluorinated species. Additionally, destruction of organofluorines can be energy intensive and expensive. Furthermore, isolation of organofluorines in solid substrates can also lead to organofluorine leaching, which is undesirable.

[0010] It would be advantageous to overcome or at least alleviate one or more of the above issues, or at least provide the consumer with a useful or a commercial alternative.

SUMMARY OF THE INVENTION

G00111 In a first aspect, although it need not be the only or indeed the broadest form, the invention resides in a method of capturing an organofluorine from a liquid, including the steps of: a) contacting a liquid comprising an organofluorine with a sorbent to form an organofluorine sorbed material; and b) contacting the organofluorine sorbed material with one or more binders to form an organofluorine captured material, to thereby capture the organofluorine from the liquid.

G00121 In a second aspect, the present invention relates to a method of capturing an organohalogen from a liquid, including the steps of: a) contacting a liquid comprising the organohalogen with a sorbent to form an organohalogen sorbed material; and b) contacting the organohalogen sorbed material with one or more binders to form an organohalogen captured material, to thereby capture the organohalogen from the liquid. [0013] In one embodiment, the organohalogen is selected from the group consisting of organofluorine, organochlorine, organobromine and organofluorine. In some embodiments, the organohalogen is organofluorine.

G00141 To the inventors’ knowledge efforts to date of disposing of organofluorines have involved methods of destroying the organofluorines. In stark contrast, the present application is directed toward methods in which the organofluorines can be safely disposed of without destruction.

100151 In some embodiments, the liquid comprising the organofluorine is produced by a pre-concentration step. The pre-concentration step may include an electrochemical and/or a chemical process. In embodiments wherein the liquid comprising the organofluorine is not pre-concentrated then the method may be considered a method of treating a liquid contaminated with an organofluorine.

[00161 In some embodiments, the liquid comprising the organofluorine is a liquid foam. [00171 In one embodiment, the sorbent is selected from the group consisting of charcoal, peat, biochar, lignin, zeolite (including attapulgite, bentonite or similar), ion exchange resins, metal oxide. Preferably, the sorbent is activated carbon.

[00181 In certain embodiments, the binder is selected from the group consisting of concrete, cement, polymer modified concrete, polymers, sol-gel-silicates, silicate, lime, plaster, clays, starches, lignosulfonates, molasses, bitumen, fly ash, calcium aluminate, cellulose gum, fuller’s earth, asphalt material, sucrose, waste paper, wax, and silica.

[00191 Without wishing to be bound by theory, the inventors believe that one reason why cement is an effective binder is because the internal pH of cement is basic, which keeps the organofluorine in an ionised form and held within the captured material. [00201 In an embodiment, the sorbent is an absorbent.

[00211 In an alternative embodiment, the sorbent is an adsorbent.

[00221 In some embodiments, step a) and b) are performed substantially concurrently.

[00231 In an embodiment, step a) is performed first and then step b) is performed. 10024] In some embodiments, the method further includes step al) filtering the organofluorine sorbed material.

100251 In an embodiment, the method further includes the step c) applying a sealant to the organofluorine captured material. In one embodiment, step c) is performed substantially concurrently with steps a) and b). In another embodiment, step c) is performed after steps a) and b).

10026] In another aspect, the invention resides in an organofluorine captured material formed by the method of the first aspect, or in an organohalogen captured material formed by the method of the second aspect. [0027] In one embodiment, the organofluorine captured material is pavement and/or construction material.

[0028] The various features and embodiments of the present invention referred to in the individual sections above and in the description which follows apply, as appropriate, to other sections, mutatis mutandis. Consequently, features specified in one section may be combined with features specified in other sections as appropriate.

[0029] Further features and advantages of the present invention will become apparent from the following detailed description.

BRIEF DESCRIPTION OF THE DRAWINGS [0030] To assist in understanding the invention and to enable a person skilled in the art to put the invention into practical effect, preferred embodiments of the invention will be described by way of example only with reference to the accompanying drawings, in which:

FIG 1 is a schematic of a comparative test between the present invention and a control (no sorbent).

DETAILED DESCRIPTION OF THE INVENTION

[0031] Embodiments of the present invention reside primarily in a method of capturing an organofluorine. Accordingly, the method steps have been illustrated in concise schematic form in the drawings, showing only those specific details that are necessary for understanding the embodiments of the present invention, but so as not to obscure the disclosure with excessive detail that will be readily apparent to those of ordinary skill in the art having the benefit of the present description.

[0032] In this specification, adjectives such as first and second, left and right, and the like may be used solely to distinguish one element or action from another element or action without necessarily requiring or implying any actual such relationship or order.

[0033] As used herein, terms such as “comprises” or “includes” are intended to define a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed, including elements that are inherent to such a process, method, article, or apparatus.

[0034] As used herein, the term ‘about’ means the amount is nominally the number following the term ‘about’ but the actual amount may vary from this precise number to an unimportant degree.

[0035] The invention is predicated on, in part, the finding that a sorbent can be utilized to sorb organofluorine compounds from a liquid source. This organofluorine sorbed material may be combined with a binder to form an organofluorine captured material, and this organofluorine captured material has been advantageously found to not significantly leach the captured organofluorine back into groundwater or the water supply generally. As such, the organofluorine captured material may be utilized in numerous uses without organofluorine leaching being a significant environmental concern.

[0036] As used herein, the term ‘sorbent’ refers to a substance which has the property of collecting molecules of another substance by sorption. It will be appreciated that the term ‘sorbent’ includes within its scope ‘absorbent’ and ‘adsorbent’. In this regard, the term ‘absorbent’ refers to a substance which takes in another substance, and the term ‘adsorbent’ refers to a substance which adheres another substance onto its surface.

[0037] It will be appreciated that the present method could be utilized with ‘absorption’ (the process by which one substance is absorbed by another) and ‘adsorption’ (the process by which a solid adheres molecules of a gas or liquid on a surface thereof). As such, the term ‘sorption’ and the like can be used interchangeably with terms ‘absorption’, ‘adsorption’ and ‘absorption and/or adsorption’. Similarly, the term ‘sorbent’ and the like may be used interchangeably with the terms ‘absorbent’, ‘adsorbent’ and ‘adsorbent and/or adsorbent’.

[0038] It will be appreciated that the reference to “a liquid comprising an organofluorine” includes any substance with a not insignificant liquid component and also comprising at least one organofluorine. While aqueous solutions of organofluorines are therefore explicitly considered, so are substances with a lower liquid content such as foams and the like.

[0039] In one aspect, the present invention resides in a method of capturing an organohalogen from a liquid, including the steps of: a) contacting a liquid comprising an organohalogen with a sorbent to form an organohalogen sorbed material; and b) contacting the organohalogen sorbed material with one or more binders to form an organohalogen captured material; to thereby capture the organohalogen from the liquid.

[0040] In one embodiment, the organohalogen is selected from the group consisting of an organofluorine, an organochlorine, an organobromine and an organofluorine. In some embodiments, the organohalogen is an organofluorine.

[0041] As used herein, the term “organofluorine” refers to substances or compounds that includes a carbon-fluorine bond. In some embodiments, an organofluorine includes a fluoroalkyl group, and may be an fluoroalkyl substance or compound. The “fluoroalkyl group” is an alkyl group (as defined below) which is substituted by at least one fluorine. The fluoroalkyl may be optionally substituted. The fluoroalkyl may be a polyfluoroalkyl or a peril uoroalkyl. In one embodiment, at least 10% of the carbon atoms in the substance or compound is substituted by a fluorine, especially at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80% or at least 90% of the carbon atoms in the substance or compound is substituted by a fluorine. In one embodiment, all carbon atoms in the substance or compound are substituted by a fluorine. [0042] In one embodiment, the organofluorine or fluoroalkyl group has a degree of fluorination of at least 10%, especially at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80% or at least 90%. The organofluorine or fluoroalkyl group may have a degree of fluorination of 100%. As used herein, the term “degree of fluorination” refers to a percentage of the number of fluorine atoms covalently bonded to carbon atoms in the organofluorine, divided by the total number of sites at which a fluorine could be bonded to a carbon in the organofluorine (including sites where monoatoms are bonded (such as hydrogen and other halogens), but not including sites where functional groups including more than one atom are bonded (such as amino groups, nitro groups, sulfate groups, and other alkyl groups)). For example, perfluorooctanoate, and perfluorooctane sulphonamide both have a degree of fluorination of 100%. Trichlorofluoromethane would have a degree of fluorination of 25%, and 1,1,2-trichlorotrifluoroethane would have a degree of fluorination of 50%.

[0043] The organofluorine may include an ionic group. The ionic group may be an anionic group or a cationic group. The ionic group may be ionic at a pH of about 7. An anionic group (or a group that carries a negative charge) may include, for example, an acidic group. The anionic group may include, for example, a sulfate, a nitrate, a phosphate, or a carboxylate. A cationic group (or a group that carries a positive charge) may include, for example, basic group. The cationic group may include, for example, a nitrogen containing group such as an amine, an imine or a nitrogen-containing heterocycle (such as an indole, imidazole, purine or pyrimidine). Exemplary cycloalkyl groups may include cyclopropyl, cyclobutyl, cyclopentanyl, cyclohexanyl, cycloheptanyl, cyclooctanyl, decahydronaphthalyl, bicyclo[3.1.0]hexanyl, bicyclo[4.1.0]heptanyl, bicyclo[3.1.1]heptanyl, bicyclo[2.2. l]heptanyl, adamantanyl and spiranes such as spiro[4.5]decane.

[0044] As used herein the term “alkyl” refers to a straight chain, branched or cyclic saturated hydrocarbon group. The alkyl group may have from 1 to 24 carbon atoms, especially from 1 to 12 carbon atoms, more especially from 1 to 6 carbon atoms or from 7 to 12 carbon atoms. Where appropriate, the alkyl group may have a specified number of carbon atoms, for example, Cl-6alkyl which includes alkyl groups having 1, 2, 3, 4, 5 or 6 carbon atoms in a linear, branched or cyclic arrangement. Examples of suitable alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, i-propyl, n-butyl, t-butyl, i-butyl, n-pentyl, 2-methylbutyl, 3-methylbutyl, 4-methylbutyl, n-hexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 5-methylpentyl, 2-ethylbutyl, 3-ethylbutyl, heptyl, octyl, nonyl, decyl, undecyl and dodecyl. The alkyl group may include 7, 8, 9, 10, 11 or 12 carbon atoms. The alkyl group may be a straight chain or branched alkyl group. The alkyl group may be a cycloalkyl group.

[0045] The organofluorine and/or the alkyl group may be optionally substituted, for example, with one or more of an alkyl (including Cl -6 alkyl), halo (including chloro, bromo or iodo), nitro, cyano, alkenyl, hydroxy, alkynyl, -O-Ri, sulfate, carboxyl, -CO-O- Ri, -O-CO-Ri, aryl, heterocyclyl, heteroaryl, -S-Ri, -SO2NH2, amino, -NH-Ri, -N-(R_I)2 or a phosphate, wherein Ri is selected from the group consisting of an alkyl, alkenyl, alkynyl, aryl, heteroaryl or heterocyclyl; wherein the alkyl, alkenyl, alkynyl, aryl, heteroaryl or heterocyclyl groups may be optionally substituted with one or more substituents selected from cyano, hydroxyl, nitro, halo, alkyl, haloalkyl, alkenyl, alkynyl or -O-alkyl groups.

[0046] As used herein, the term “alkenyl” refers to refers to a straight-chain, branched or cyclic hydrocarbon group having one or more double bonds between carbon atoms. The alkenyl group may have from 2 to 12 carbon atoms. Where appropriate, the alkenyl group may have a specified number of carbon atoms. For example, C2-C6 as in "C2-C6 alkenyl" includes groups having 2, 3, 4, 5 or 6 carbon atoms in a linear, branched or cyclic arrangement. Examples of suitable alkenyl groups include, but are not limited to, ethenyl, propenyl, isopropenyl, butenyl, butadienyl, pentenyl, pentadienyl, hexenyl, hexadienyl, heptenyl, octenyl, nonenyl, decenyl, undecenyl and dodecenyl.

[0047] As used herein, the term “alkynyl” refers to a straight-chain, branched or cyclic hydrocarbon group having one or more triple bonds between carbon atoms and having 2 to 12 carbon atoms. Where appropriate, the alkynyl group may have a specified number of carbon atoms. For example, C2-C6 as in "C2-C6 alkynyl" includes groups having 2, 3, 4, 5 or 6 carbon atoms in a linear, branched or cyclic arrangement. Examples of suitable alkynyl groups include, but are not limited to, ethynyl, propynyl, butynyl, pentynyl, hexynyl, octynyl, nonynyl, decynyl, undecynyl and dodecynyl.

[0048] As used herein, the term “aryl” refers to any stable, monocyclic, bicyclic or tricyclic carbon ring of up to 7 atoms in each ring, wherein at least one ring is aromatic. When more than one ring is present, the rings may be fused to one another. Examples of aryl groups include, but are not limited to, phenyl, naphthyl, tetrahydronaphthyl, indanyl, biphenyl, binaphthyl, anthracenyl, phenanthrenyl, phenalenyl and fluorenyl.

[0049] As used herein, the term "heterocyclyl" refers to a cycloalkyl or cycloalkenyl group in which one or more carbon atoms have been replaced by heteroatoms independently selected from N, S and O. For example, between 1 and 4 carbon atoms in each ring may be replaced by heteroatoms independently selected from N, S and O. The heterocyclic group may be monocyclic, bicyclic or tricyclic in which at least one ring is heterocyclic. When there are two or three rings, each ring is linked to one or more of the other rings by sharing one or more ring atoms forming a spirane or fused ring system. The heterocyclyl group may also include a carbonyl group attached to an unsaturated ring carbon, Examples of heterocyclyl groups may include tetrahydrofuranyl, tetrahydrothiophenyl, pyrrolidinyl, 2-pyrrolidonyl, pyrrolinyl, dithiolyl, 1,3-dioxolanyl, pyrazolinyl, imidazolinyl, imidazolidonyl, 1,4-dioxanyl, 1,3- dioxanyl, dioxinyl, piperidinyl, piperazinyl, morpholinyl, thiomorpholinyl, pyranyl, 1,4- dithiane, 1,3,5-trithiane, quinuclidine and tetrahydropyranyl.

[0050] As used herein, the term "heteroaryl" refers to a stable monocyclic, bicyclic or tricyclic ring of up to 7 atoms in each ring, wherein at least one ring is aromatic and at least one ring contains from 1 to 4 heteroatoms selected from the group consisting of O, N and S. When more than one ring is present the rings may be fused. The heteroaryl group may also include a carbonyl group attached to an unsaturated carbon in the ring system. Examples of heteroaryl groups include pyrrolyl, furanyl, thienyl, pyrazolyl, imidazolyl, pyridinyl, pyridazinyl, pyrimidinyl, indolyl, benzimidazolyl, benzopyranyl, quinolinyl, tetrahydroquinolinyl, isoquinolinyl, quinazolinonyl, and quinazolindionyl.

[0051] As used herein, the term “foam” relates to a gas entrained in another continuous phase. The foam may include gaseous bubbles of any suitable diameter. In one embodiment, the foam includes gaseous bubbles of a diameter (or the foam includes bubbles of an average diameter) of at least 300 pm; especially at least 400 pm, at least 500 pm, or at least 600 pm; more especially at least 700 pm or at least 800 pm.

[0052] The organofluorine may be of formula (I):

R-Y

Formula (I) wherein R is a fluoroalkyl group, and wherein Y is an ionic group. The fluoroalkyl group may be optionally substituted. The fluoroalkyl group may be as defined above. The ionic group may be as defined above.

[0053] The sorbent is suitably an absorbent and/or an adsorbent. The sorbent is a material that is able to capture organofluorines. Suitable commercial sorbents may be chosen on the basis of their known properties to either take up liquid materials, such as organofluorine-containing liquids, or to hold such organofluorines on their surface on a physical or chemical attraction basis. Suitable examples of sorbents include, but are not limited to, charcoal, peat, biochar, lignin, zeolite, ion exchange resins, metal oxide.

[0054] Non-limiting examples of peat include, humin and humic acids. Non-limiting examples of ion exchange resins include anion exchange resins such as Oasis WAX Plus. Non-limiting examples of the metal oxide include aluminum oxide (acid and base forms), iron oxide, titanium dioxide (both rutile and anatase), alkaline earth oxides, red mud mixtures, manganese oxide, zinc oxides, copper oxides, sol-gel metal oxides, silicon oxides, derivatized silicon oxides, oxide supported ion exchange resins, tungsten oxides tin oxides and combinations thereof. Preferably, the sorbent is activated carbon. In one embodiment, the activated carbon is granular activated carbon. It will be appreciated that sorbents functionalized to sorb specific target materials will be dependent on the functionality of the sorbent.

[0055] Without being bound by any theory, it is postulated that the sorbent has an affinity for organofluorines. In this regard, it is postulated that the organofluorine can be adsorbed onto the surface of an adsorbent and/or the organofluorine can be absorbed into an absorbent. Once adsorbed or absorbed, the organofluorine is associated and/or bound to the absorbent and/or adsorbent.

[0056] Testing indicates that when the organofluorine sorbed material is combined with one or more binders, the organofluorine in this organofluorine captured material advantageously does not exhibit significant leaching into water. As such, it is postulated that organofluorines captured in this manner do not require the organofluorine to be destroyed or degraded as it is unavailable to the environment. Additionally, the environmental issues associated with organofluorines are alleviated. The organofluorine of the organofluorine captured material can be slowly left to decompose without exhibiting substantial leaching or, otherwise, remain in a captured state. [0057] As the organofluorine captured material does not appear to leach significant amounts of organofluorine, it is postulated that, in addition to the organofluorine not being required to be destroyed, the organofluorine sorbed material may be utilized in other uses. One non-limiting example is that the organofluorine sorbed material may be utilized as pavement and/or a construction material.

[0058] The binder may be an organic binder or an inorganic binder. Suitably, the binder is in the form of a flake, granule or powder. Typical binders will produce strong final agglomerates, permanently bound particles that can withstand the rigors of storage, handling, packaging and shipping.

[0059] Non-limiting examples of the binder include concrete, cement, polymer modified concrete, polymers, sol-gel-silicates, silicate, lime, plaster, clays, starches, lignosulfonates, molasses, bitumen, fly ash, calcium aluminate, cellulose gum, fuller’s earth, asphalt material (gilsonite), sucrose, waste paper, wax, and silica. Non-limiting examples of the clays include bentonite, siliceous clay material (Fuller’s earth) and attapulgite, palygorskite or similar clay minerals. A non-limiting example of the cement include magnesium phosphate cements and Portland cement. A non-limiting example of starch is com starch. Non-limiting examples of silicates include sodium silicate and alumina silicate. A non-limiting example of lime is hydrated lime. Non-limiting examples of the polymer include synthetic polymers (solid, solution or dispersion form; ‘Alcotac’), cellulose-derived water soluble polymer (‘Peridur’), polyvinyl alcohol (PVA), liquid polybutadiene emulsion (‘Terravesf ). In one embodiment, the binder is cement or concrete.

[0060] Shown in FIG 1 is tests performed for foam water containing organofluorine (discussed in more detail hereinafter). The sorbent used in these experiments are activated carbon (experiments 1193-012 and 1193-013), biochar/charcoal (experiments 1193-014 and 1193-015), zeolites (experiments 1193-016 and 1193-017) and a control with no sorbent (experiment 1193-010).

[0061] The foam water (liquid comprising organofluorine) was first mixed with the sorbent (or lack thereof) for 1 day or overnight. The resultant sorbed material was then added to binder cement/carbon to form an organofluorine captured material (experiments 1193-010; 1193-012; 1193-014; and 1193-016). A second test was completed wherein the organofluorine captured material was coated with an epoxy resin to further prevent ingress of water (experiments 0093-011; 1193-013; 1193-015; and 1193-017). The epoxy resin was present as the cement sets. It is believed that the epoxy resin acts as both sealant and is a contributor to structural stability. This was allowed to cure for 4 days before being subjected to a 7-day distilled water leachate test.

[0062] In light of the above, the method may further include the step of applying a sealant to the organofluorine captured material. This is believed to prevent the ingress of water, and thus further alleviates the problem of leaching of organofluorine.

[0063] The sealant may be suitably a polymer. Non-limiting examples of the polymer include epoxies, acrylates, methacrylates, shellacs, glass ionomer sealants, urethanes, siliconates and polyethylenes. In one embodiment, the sealant is a superplasticizer. The superplasticizer may be derived from sulfonated melamine formaldehyde condensate, sulfonated naphthalene formaldehyde condensate, acetone formaldehyde condensate or polycarboxylate ethers. In one embodiment, the sealant may comprise organofluorine sorbed material as described hereinabove.

[0064] In one embodiment, step a) and step b) of the method are completed substantially concurrently. That is, an organofluorine is contacted with the sorbent and the binder in a ‘one-pot’ step to capture the organofluorine. In another embodiment, steps a), b) and c) are completed substantially concurrently. For example, when the sealant is a superplasticizer, it is believed that the sealant is able to simultaneously bond with the sulfonate or carboxylate structure of the organofluorine and the divalent charged alkaline earth components of the binder mixtures which may include (for example) cement.

[0065] In another embodiment, step a) and step b) of the method are completed sequentially. That is, the liquid comprising the organofluorine is first contacted with the sorbent, and allowed to mix for set period of time. The resultant organofluorine sorbed material is then contacted and/or mixed with a binder and allowed to cure.

[0066] In an embodiment, step a) is performed for a period of at least about 30 minutes, at least about 1 hour, at least about 2 hours, at least about 4 hours, at least about 6 hours, at least about 8 hours, at least about 10 hours, at least about 12 hours, at least about 14 hours, at least about 16 hours, at least about 18 hours, at least about 20 hours, at least about 22 hours or at least about 24 hours. Preferably, step a) is contacted or mixed overnight or for about 24 hours.

[0067] In one embodiment, step b) is left for a period of at least about 12 hours, at least about 1 day, at least about 2 days, at least about 3 days or at least about 4 days, Preferably, step b) is left for a period of about 4 days to cure.

[0068] In the embodiment where step a) and b) are completed concurrently, step a) and b) is mixed and/or left for a total of at least about 12 hours, at least about 1 day, at least about 2 days, at least about 3 days or at least about 4 days. Preferably, step a) and step b) is mixed and/or left for a total of about 4 days.

[0069] In one embodiment, the method further includes step al) filtering the organofluorine sorbed material. In this regard, the organofluorine sorbed material may be separated from the liquid components of the liquid. The organofluorine sorbed material will likely be a solid and can be used as an aggregate with the one or more binders.

[0070] Alternatively, it will be appreciated that both the liquid component and the organofluorine sorbed material may be utilized with the one or more binders. For example, the water component of the liquid component could be used as the hydrating component for cement or concrete.

[0071] The liquid comprising the organofluorine may be, for example, a groundwater, a landfill leachate, or an industrial waste. For example, groundwater from airports and military installations may be contaminated with firefighting foams which may require treatment. The liquid may be an aqueous liquid which includes an organofluorine. The liquid may comprise more than one type of organofluorine and, in embodiments, may comprise one or more organofluorines from those described herein.

[0072] The liquid comprising the organofluorine may be obtained by a pre concentration method. The pre-concentration may include electrochemical (discussed in more detail hereinafter) and/or chemical processes. Non-limiting examples of the pre concentration methods include electrochemically enhanced foam fractionation, metal saponification enhanced foam fractionation, electrochemical or saponification methods combined with evaporation, electrochemical or chemical ionization combined with electrophoresis, pre-concentration based on adsorption, and pre-concentration based on partitioning combined with evaporation.

[0073] In an embodiment, the liquid comprising the organofluorine is obtained by electrochemically treating a liquid to thereby produce a foam and an electrically treated liquid. The foam includes the organofluorine, and may be separated from the liquid component. The collected foam can then be contacted with the sorbent.

[0074] The method may include the step of electrochemically treating the liquid using an electrochemical treatment apparatus. The electrochemical liquid treatment apparatus may include a treatment chamber including at least one inlet for entry of a liquid to be treated, and at least one outlet for exit of electrochemically treated liquid, and a plurality of electrodes positioned within the treatment chamber for electrochemical treatment of the liquid.

[0075] Electrochemical treatment takes advantage of the characteristics of any organofluorines to separate out the organofluorines, or at least concentrate the organofluorines. Electrochemical treatment provides a charged state in the organofluorine which gives the organofluorine more surfactant-like properties. In this regard, an organofluorine in a charged state increases the hydrophilicity of the hydrophilic group and this increases its affinity for polar substances. During electrochemical treatment, a gas can be bubbled through the liquid, or alternatively the electrochemical treatment may be configured to produce gas bubbles (for example, hydrogen gas may be generated at the electrodes). The gas bubbling through the liquid interacts with the organofluorines present in the liquid and becomes entrained with the organofluorine, resulting in the production of a foam. The now buoyant foam including the organofluorine floats to the surface of the liquid, where it may then be collected to separate the organofluorine.

[0076] Advantageously, while some organofluorines may be degraded due to the electrochemical treatment, the electrochemical treatment may be effective without degrading the organofluorine (and organofluorine degradation products may also produce foams in the electrochemical treatment). For example, for an organofluorine surfactant, the method takes advantage of the surfactant properties of the organofluorine to produce a foam in the electrochemical treatment and effect separation (the organofluorine surfactant stabilises the foam). Furthermore, some organofluorines may not produce a foam in the electrochemical treatment (either due to the characteristics of the organofluorine, or due to the conditions under which the electrochemical treatment is performed). However, foam-forming organofluorines may draw non-foaming organofluorines into the foam layer, thereby improving separation.

[0077] Some organofluorines or degradation products thereof may also not be drawn into the foam layer; instead Hoc may be produced during the electrochemical treatment which includes such organofluorines or degradation products thereof. After the electrochemical treatment such Hoc may settle out of the treated liquid where it may be separated (for example the Hoc may be drained from the treated liquid and the resulting contaminated sludge then passed through a screw press for subsequent disposal as an essentially dry cake).

[0078] As used herein, the term “Hoc” relates to a solid material initially dispersed in the liquid phase. For the avoidance of doubt, gaseous bubbles may be entrained in the Hoc resulting in a temporary flotation of the solid material. However, bubbles which nucleate on a dispersed solid are not a foam as the solid does not form a continuous boundary around the gas. The solid material may be formed, for example, by reaction between suspended metal oxide species (for example from the anode) and contaminants in the liquid.

[0079] For avoidance of doubt, the foam produced during electrochemical treatment may not include all organofluorine, but the foam would include at least a portion of the organofluorine from the liquid. The organofluorine may preferentially be part of the foam over the electrochemically treated liquid.

[0080] The foam may suitably be separated from the liquid and then ‘defoamed’. This decreases the volume of foam (or bubbles) after electrochemical treatment and facilitates easy transfer of the liquid to be treated by the sorbent.

[0081] The electrochemical process and apparatus for electrochemical treatment are described in Australian provisional patent application No. 2018904387 (and PCT Application No. PCT/AU2019/051263) which is incorporated in its entirety by reference.

[0082] In an embodiment, the liquid is obtained by chemically treating a liquid to thereby produce a foam and a chemically treated liquid. The foam includes the organofluorine.

[0083] Surfactants in general are described as being amphiphilic (molecules that have distinct regions within the molecule which are more hydrophilic or hydrophobic). The most common type of surfactant material has a headgroup which is normally thought of as hydrophilic and a long tail which is chemically considered hydrophobic. In a mixture of immiscible phases, these physical characteristics result in a preferred orientation of these molecules such that the molecule tends to orient itself such that the hydrophilic region of the molecule resides in the aqueous region and the hydrophobic part of the molecule resides in the immiscible non-aqueous phase. This arrangement can only be realized at an interface between the two phases.

[0084] Soap is the most recognized example of a surfactant. Soaps are created in a process called saponification where a fatty acid (nominally a weak organic acid) is caused to react with a strong base under elevated temperature conditions. The original fatty acid has only weak surfactant tendencies due to the relatively weak ionization of the headgroup. After saponification the ionized form (conjugate base form of the fatty acid) is produced. The ionized form of the molecule has a much stronger interaction with the aqueous environment and as such the molecule acquires a much greater surfactant tendency. In surface chemistry one quantifies this surfactant tendency with the term HLB or hydrophile lipophile balance.

[0085] Perfluorocarbon surfactant materials are different in that the fluorinated region of the molecule is neither hydrophilic nor oleophilic. The perfluorinated region is most stable outside of the solvated environment. This suggests that these materials are most prone to segregate to gas-liquid interfaces and this is consistent with the use of these materials in firefighting foams. To function as a surfactant a regional headgroup of hydrophilic character is necessary. In perfluorocarbon acids this regiospecific hydrophilic group is the acidic functionality. Similar to the normal organic soaps this acidic headgroup may be a strong or weak acid (i.e. the ionization constant K_a can be larger or smaller). The ionized form of the molecule has a much stronger affinity for the aqueous environment and thus is a more powerful surfactant. Chemical conditions which drive ionization are most conducive to segregation of the surface-active molecule to an interface. For a fluorocarbon acid this means that a basic environment is most conducive to generation of the molecular moiety with greatest surfactant tendencies. Similarly, for a fluorocarbon base, an acidic environment will produce a more surfactant prone moiety. For derivatized species, such as amides and esters, chemical environments which cleave the weaker bonds producing free acids and bases are preferred chemical environments for separation. [0086] Once the equilibrium has been shifted to generate the largest fraction of highly surface-active materials by appropriate chemical means, then segregation is achieved by generation of the appropriate immiscible phase followed by physical separation of the two immiscible phases. For perfluorocarbon molecules this can be by gas generation, introduction of smaller diameter bubbles being the preferred method as these bubbles have the greatest surface to volume ratio. The methods include:

Electrochemical gas generation

External introduction of gas

Use of a dissolved air flotation device

Chemical gas generation for example by liberation of CO2 by chemical means

[0087] Other examples of generation of an immiscible phase would be the introduction of a solid material for which the normally hydrophilic headgroup has even greater attraction and then separation of this material using dissolved air flotation, or the use of an ion exchange resinous material which preferentially binds the ionized headgroups followed by physical separation.

[0088] In one embodiment, a gas is used as the immiscible phase by a combination of methods (chemical, electrochemical and external gas introduction into the reactor where the surfactant form is being generated). The stabilized form phase is enriched in the perfluorocarbon species and is separated by taking advantage of the density and surface tension of the foam phase. As the liquid/foam mixture flows across a wire mesh surface the more dense phase passes through the mesh and the less dense phase does not. A vacuum system is used to collect the surfactant rich foam phase. If the air speed in the vacuum collection system is sufficient, a benefit of this collection method is that the aerodynamic instability of the bubbles comprising the foam causes the foam to collapse into a much smaller collection volume.

[0089] In one embodiment, the organofluorine sorbed material is not a low volume activated carbon stream which carries the bulk of the PFOA contaminant, and is not absorbed to a largely inert ferric sludge or similar waste cementation / encapsulation process. In one embodiment, the sorbent is not activated carbon and/or the binder is not cement. Further information regarding the electrochemical process

[0090] The electrochemical process comprises a method that may include the step of removing or depleting ammonia or ammonium from the liquid prior to the electrochemical treatment. Suitable ways of removing or depleting ammonia or ammonium from a liquid would be known to a skilled person. For example, air or steam stripping or chemical precipitation may be used. The step may include basifying the liquid, for example by adding a base to bring the pH of the liquid above 9, especially above 10, more especially above 11, most especially above 11.5. The basic liquid may be heated, for example to at least 30 °C, especially at least 40 °C, more especially at least 50 °C, most especially at least 60 °C. The heated liquid may be cooled. The basic liquid may be acidified, for example by adding an acid to bring the pH of the liquid below 11, especially below 10, more especially below 9 or below 8, most especially between about 5 to 9, or about 6 to 8, or to about 7.

[0091] In another example, the method may include the step of removing or depleting ammonia / ammonium by chemical precipitation. For example, a magnesium salt (such as magnesium chloride) and/or a phosphate salt (such as sodium phosphate) may be added to form a precipitate such as a magnesium ammonium phosphate precipitate (such as struvite). The precipitate may be relatively insoluble in water. The chemical precipitate may be settled and/or filtered from the liquid.

[0092] In some embodiments, removal or depletion of ammonia or ammonium may be advantageous to decrease or minimise the production of sulfonamides which may not separate into the foam.

[0093] The method may include the step of filtering the liquid prior to the electrochemical treatment. The step of filtering the liquid may remove large particulate solids from the fluid stream that could otherwise become lodged between electrodes and disrupt the functioning of an electrochemical treatment apparatus.

[0094] The method may include the step of electrochemically treating the liquid using an electrochemical treatment apparatus. The electrochemical liquid treatment apparatus may include a treatment chamber including at least one inlet for entry of a liquid to be treated, and at least one outlet for exit of electrochemically treated liquid, and a plurality of electrodes positioned within the treatment chamber for electrochemical treatment of the liquid. The electrochemical liquid treatment apparatus is as described in Australian provisional patent application No. 2018904387 (and PCT Application No. PCT/AU2019/051263). [0095] The method may include the step of introducing a liquid to be treated. The method may include the step of applying a voltage to at least two of a plurality of electrodes to provide at least one cathode and at least one anode to thereby electrochemically treat the liquid. The method may include the step of removing electrochemically treated liquid. [0096] The method may include the step of generating floe as the liquid is electrochemically treated. The method may include the step of removing floe. The method may also include the step of introducing at least one treatment agent, especially in which the treatment agent is a gas or an oxidant or reductant. The treatment agent may be as described below. The method may also include the step of applying a treatment enhancer. In a further embodiment, the method includes the step of reversing the polarity of the at least one cathode and the at least one anode during the electrochemical treatment.

[0097] The liquid may be electrochemically treated at any suitable temperature or pressure. However, the electrochemical treatment is especially performed at atmospheric temperature and pressure.

[0098] During the electrochemical treatment, iron in the electrodes (if present) may be released into the liquid from the anode as Fe²⁺ or Fe³⁺. Meanwhile at the cathode water may break down into hydrogen gas and hydroxyl ions.

[0099] As hydrogen gas is a reducing agent, the gas would mean that the iron in the solution is more likely to be Fe²⁺ (and therefore the floe is more likely to be ferrous floe). Furthermore, the hydrogen gas may form bubbles with the organofluorine, which thereby produces foam.

[00100] During the electrochemical treatment the pH may be raised due to the formation of hydroxyl ions. However, under relatively basic conditions (pH 7-10) most metal oxides and hydroxides become less soluble, which results in the formation of suspended metal oxy-hydroxide species. The stability of these suspensions may be determined by various factors including the zeta potential (or electric potential) in the interfacial double layer surrounding the metal oxy-hydroxide particle and the liquid. The presence of other charged material in the liquid (such as dissolved contaminants, especially dissolved ionic contaminants) may lower this zeta potential, decrease the stability of the suspended metal oxy-hydroxide and cause aggregation and Hoc formation. This aggregate or Hoc can form over a wide pH range, and Hoc from electrochemical (or electrocoagulation) reactions may have physical properties that are more disperse and easily compacted than aggregates formed by chemical coagulation. This means that the greater special extent of floes formed electrochemically provide more capacity to entrain contaminants.

[00101] The electrochemical treatment may be performed at any suitable residence time, effective voltage per cell and flow rate. Suitable residence times, effective voltages per cell and flow rates are discussed below.

[00102] The method may include the step of adding a treatment agent to the liquid. Treatment agents may be as described below. The use of treatment agents may assist in the production of solids including fluorine. The use of treatment agents may assist in the initial separation of fluorine from the liquid and/or in the partitioning to either a generated foam or to a miscible polymeric liquid used to remove (or strip) fluorine containing compounds from the foam. The liquid can be separated following this treatment as outlined below. Treatment agents might also be used for the partitioning of generated fluorine to a solid Hoc or layered ferro, ferri-hydroxy, hydrotalcite, ettringite or similar layered hydroxide sludge. For example, suitable treatment agents may include chlorine-containing agents (such as chlorine salts such as sodium or potassium chloride). Without wishing to be bound by theory, it is believed that the chlorine, especially in combination with hydroxyl, sulfate and similar highly active radicals, may be able to displace fluorine in the organofluorine during the electrochemical treatment (or energetically displace fluorine from organofluorine compounds and intermediates encountered during the electrochemical treatment). Another suitable treatment agent may include alkaline earths, such as calcium or magnesium-containing agents (such as magnesium salts such as magnesium chloride). Without wishing to be bound by theory, it is believed that the alkaline earths (especially magnesium) may react with fluorine generated in the electrochemical treatment, especially to form highly insoluble magnesium fluoride compounds. Gaseous treatment agents may also be used in the electrochemical treatment to increase foam production (which may assist in capture and separation of fluorine containing contaminants present as surfactants). Furthermore, at least some chlorine gas may be formed at the anode from chloride ions and may react with molecular dioxygen to form dioxygen dichloride, which could assist in oxidising fluorine compounds. Treatment agents such as defoaming liquids may also be chosen to have a high affinity to fluorinated hydrocarbons present as foam (and may remain immiscible to a varying extent with cleaner water by virtue of relative insolubility - as will be known to those skilled in the art). Defoaming liquids may be chosen such that they preferentially absorb or react with dissolved fluorocarbons regardless of chain length whilst being separable from the cleaned, treated water by virtue of either their lower density or switchable miscibility at the oil-water interface encountered during treatment.

[00103] The electrochemical treatment may involve substantially laminar flow of liquid between the electrodes or turbulent flow of liquid between the electrodes; especially substantially laminar flow.

[00104] During the electrochemical treatment the electrodes may switch from anode to cathode. This may assist in the electrochemical treatment as when the electrodes switch reaction products previously close to an anode are now close to a cathode.

[00105] If needed, the efficiency of the electrochemical treatment in removing or depleting organofluorines may be improved by increasing the residence time, increasing the current applied to the liquid, slowing the flow rate or increasing the contact time of fluorine containing compounds (especially active fluorine containing compounds) with magnesium ions present or added. However, generally these steps may also decrease the throughput or increase the energy consumption of the system, which may not be desirable.

[00106] Without wishing to be bound by theory, it is also believed that longer chain organofluorines (such as perfluorooctanoate) may be more likely to form foam during the electrochemical treatment. However, shorter chain organofluorines (such as perfluorobutanoate) may be more likely to become part of the Hoc. Accordingly, it may be preferable to utilise dissolved air flotation (DAF) in combination with treatment agents (such as those described above and below) to maximise removal of fluoridated compounds from the liquid being treated.

[00107] Very strong oxidants may be needed to break C-F bonds due to their strength. Advantageously, in the electrochemical treatment free radicals (such as sulfate and hydroxyl) may be formed which are highly chemically reactive, but which have a very short lifetime. The electrochemical treatment may extend the lifetime of the free radicals due to the development of free radical chain reactions in the liquid being treated. If the lifetime of the free radicals are extended, then this can provide a more persistent oxidative potential in the electrochemical treatment. In any case, and without wishing to be bound by theory, it is believed that the free radicals in the electrochemical treatment may be able to attack C=C bonds and C-F bonds. Consequently, the electrochemical treatment may be effective in degrading the organofluorine compounds. Furthermore, it is believed that at least some chlorine gas formed at the anode from chloride ions may react with molecular dioxygen to form dioxygen dichloride, which could assist in oxidising fluorine compounds. Again, without wishing to be bound by theory, other chemicals which may form in the electrochemical treatment which may assist in degrading organofluorine compounds include oxygen difluoride (OF2) and chloride trifluoride (CIF3).

[00108] In one embodiment, the method further includes the step of removing Hoc from the electrochemically treated liquid. This step may include clarifying the electrochemically treated liquid in a clarifier. Floe may not settle in the electrochemical treatment (especially due to the residence time in the treatment), however given time the Hoc may settle in the clarifier. If necessary an oxidant (such as oxygen gas) may be bubbled through the clarifier to oxidise dissolved ferrous ions (Fe²⁺) to ferric ions (Fe³⁺). Ferric ions have greater affinity for some fluorinated compounds and consequently this (possibly in combination with oxygen or another treatment agent) may assist in further depleting the concentration of organofluorine compounds in the liquid.

[00109] In one embodiment, the method further includes the step of further treating the electrochemically treated liquid. In one example, the method may include the step of performing a second electrochemical treatment on the liquid to thereby produce foam and an electrochemically treated liquid, wherein the foam includes the organofluorine and/or degradation products thereof. In this example, the method may further include the step of separating the foam from the electrochemically treated liquid. In another example, the method may include the step of treating the electrochemically treated liquid with an adsorptive system or process. An adsorptive system or process may include treating the electrochemically treated liquid with activated carbon (including a granular activated carbon (GAC)). At present, organofluorine treatment processes may employ an adsorptive system or process without first separating or depleting the amount of organofluorine present in the liquid. Advantageously, the method of the present invention decreases the concentration of organofluorines present in a liquid that requires treatment. By taking this step, the lifespan of the adsorptive system or process can be extended (these systems and processes are often expensive). Furthermore, the electrochemical treatment may remove or deplete other contaminants from the liquid (such as oils, greases, humic and other organic acids) which would otherwise compete for binding sites on, for example, an activated carbon or layered double hydroxide (LDH) mineral such as hydrotalcite.

[00110] In one embodiment, the method may include the step of treating the separated foam. The method may include the step of degassing (or substantially degassing) the foam. The method may include the step of transferring the foam to a vessel, and the vessel may have a pressure below atmospheric pressure.

[00111] In one embodiment, the present invention further includes treating a liquid including an organohalogen, comprising: electrochemically treating the liquid to thereby produce foam and an electrochemically treated liquid, wherein the foam includes the organohalogen and/or degradation products thereof; and separating the foam from the electrochemically treated liquid.

[00112] Such a foam may be used as the liquid comprising the organofluorine which is to be captured, as per the first aspect. [00113] In one embodiment, the organohalogen is an organofluorine, an organochlorine, an organobromine or an organoiodine. The organohalogen may be mono, poly or per-halogenated. The organohalogen may be an organohalogen surfactant.

Examples Test Method Test method 1

[00114] Cement (Sakrete) and foam water (liquid comprising organofluorine) from the CWC 2018 pilot program were used to fabricate solid samples, in accordance with the cement water mix ratios recommended by the manufacturer. This manufacturer specifies a 1:1 cement/water mixture.

[00115] In an exemplary experiment 1 kg of the Portland cement mixture was mixed with lkG of the foam water (i.e. pre-concentrated organofluorine produced by an electrochemical method). The mixture was cast into a disposable aluminum baking pan (10.75” X 15.25” X 2.125”) and produced a thin slab of concrete after setting. The concrete slab was dislodged from the baking pan and crumbled. 50 grams of the crumbled concrete was mixed with 200mL of PFAS free water (obtained from ALS Kelso Washington Laboratory) in a PFOA free container and allowed to soak according to the TCEQ modified TCLP method. After the leaching procedure the liquid portion of the sample was filtered through a 0.45 pm filter into a PFAS sample bottle supplied by the Kelso lab and analyzed.

[00116] Organofluorine captured material samples in accordance to the present invention were prepared in a similar fashion, with the exception that modified aggregate was created by allowing 200 g of the sorbent (activated carbon) to stir overnight in 1 L of the foam water. After stirring overnight, the solid material was filtered from the suspension and added as an aggregate in a concrete mixture (3 parts of the aggregate mixed with 1 part cement (by weight)). PFOA free water was used to hydrate the cement in a proportion of 1 : 1 by weight of the Portland cement. A slab was cast as before and subjected to the same leaching protocol.

[00117] Shown in the Table 1 are the results from a leaching test completed on the sample without sorbent of Test Method 1: Table 1 - Leaching results from raw concrete

[00118] Shown in Table 2 are the results from a leaching test completed on the organofluorine captured material of Test Method 1.

Table 2 - Leaching results from aggregate modified samples of Test Method 1

[00119] It should be appreciated from these results that the use of a sorbent significantly decreased the degree of organofluorine leaching. As such, these results indicate that an organofluorine sorbed material may be used in conjunction with a binder to alleviate the problem of organofluorine leaching. Furthermore, it will be appreciated that such materials are envisaged to be utilized in paving and construction material.

Test Method 2

[00120] 520.5 g Portland cement, 150.7 g of activated carbon (Reef Spec) and 500mL of the foam water were stirred vigorously to produce a cement slurry in a single step. The mixture was cast into a disposable aluminum baking pan (10.75” X 15.25” X 2.125”) and produced a thin slab of concrete after setting. The concrete slab was dislodged from the baking pan and crumbled. 50 grams of the crumbled concrete was mixed with 200mL of PFAS free water (obtained from ALS Kelso Washington Laboratory) in a PFOA free container and allowed to soak according to the TCEQ modified TCLP method. After the leaching procedure the liquid portion of the sample was filtered through a 0.45 pm filter into a PFAS sample bottle supplied by the Kelso lab and analyzed.

[00121] Shown in Table 3 are the results from a leaching test completed on the organofluorine captured material produced from Test Method 2.

Table 3 - Leaching results from samples of Test Method 2

[00122] Similar to Test Method 1, a significant reduction in organofluorine leaching is observed. Common Organfluorine compounds

[00123] Shown in Table 4 are common organofluorine compounds, their acronyms, formula and carbon chain length.

Table 4 - Organofluorine Acronyms

Example method of forming an organofluorine captured material

[00124] Organofluorine sorbed material was prepared by adding 150g of activated charcoal (1000 m²/g density 0.48g/mL) to 1 L of drained foam concentrated PFOA solution. This mixture was allowed to stir overnight with the organofluorine sorbed material was collected via filtration but not dried.

[00125] The organofluorine captured material was then formed by mixing 35.5 mL cement (TXI Portland cement), and 71.0 g of the collected organofluorine sorbed material. No water except that present in the collected organofluorine sorbed material was added.

[00126] 23.8 mL of epoxy resin mixture (DGEBA-Epoxy resin CAS # 25068-38-6) prepared as described in the suppliers directions (nominally 12mL of epoxy resin mixed with 12mL epoxy hardener solution) was applied.

[00127] Other compositions as described in Figure 1 were prepared similarly. Example method of the chemical process

[00128] 8L of landfill leachate water was treated with sufficient caustic (50% NaOH solution in water) to raise the pH to 11.5. The temperature of this solution was raised to 140°F (60°C). The resulting solution was pumped into a rectangular vessel, dimensions (3” x3.75” x 14 “). Fluid was pumped into the bottom of the vessel with outflow at the top of the vessel. The vessel was fitted with an aeration stone (0.5 micron stainless steel aeration stone) at the bottom of the vessel. Plumbing was constructed so that gas flow to the aeration stone and liquid flow into the vessel was collinear with the liquid filling and immediately impinging on the aeration stone. Liquid and gas flow were both controlled via plumbing controls so that both liquid and gas (air) were supplied at 1.1 L/min. 13 parallel metal plates were fixed in the vessel insuring laminar combined flow in the vessel. Liquid residence time in the tower as constructed was 60 seconds. Outflow of the liquid/foam mixture from the vessel exited via a spillway. A 20 mesh metal screen was affixed to the exit spillway such that the foam/liquid effluent cascaded across the mesh. The denser liquid material passed through the mesh and the less dense foam remained on top of the mesh and was collected using a vacuum collector. [00129] The above description of various embodiments of the present invention is provided for purposes of description to one of ordinary skill in the related art. It is not intended to be exhaustive or to limit the invention to a single disclosed embodiment. As mentioned above, numerous alternatives and variations to the present invention will be apparent to those skilled in the art of the above teaching. Accordingly, while some alternative embodiments have been discussed specifically, other embodiments will be apparent or relatively easily developed by those of ordinary skill in the art. Accordingly, this invention is intended to embrace all alternatives, modifications and variations of the present invention that have been discussed herein, and other embodiments that fall within the spirit and scope of the above described invention.

Claims

1. A method of capturing an organofluorine from a liquid, including the steps of: a) contacting a liquid comprising an organofluorine with a sorbent to form an organofluorine sorbed material; and b) contacting the organofluorine sorbed material with one or more binders to form an organofluorine captured material, to thereby capture the organofluorine from the liquid.

2. The method of claim 1, wherein the liquid comprising the organofluorine is produced by a pre-concentration step.

3. The method of claim 2, wherein the pre-concentration step includes an electrochemical and/or a chemical process.

4. The method of any one of the preceding claims, wherein the sorbent is selected from the group consisting of charcoal, peat, biochar, lignin, zeolite, ion exchange resins, and metal oxide.

5. The method of any one of the preceding claims, wherein the sorbent is activated carbon.

6. The method of any one of the preceding claims, wherein the binder is selected from the group consisting of concrete, cement, polymer modified concrete, polymers, sol-gel-silicates, silicate, lime, plaster, clays, starches, lignosulfonates, molasses, bitumen, fly ash, calcium aluminate, cellulose gum, fuller’s earth, asphalt material (gilsonite), sucrose, waste paper, wax, and silica.

7. The method of any one of the preceding claims, wherein the binder is concrete and/or cement.

8. The method of any one of the preceding claims, wherein the sorbent is an absorbent.

9. The method of any one of claims 1 to 7, wherein the sorbent is an adsorbent.

10. The method of any one of the preceding claims, wherein steps a) and b) are performed substantially concurrently.

11. The method of any one of claims 1 to 9, wherein step a) is performed first and then step b) is performed subsequently.

12. The method of claim 11, further including step al) filtering the organofluorine sorbed material.

13. The method of any one of the preceding claims, further including step c) applying a sealant to the organofluorine sorbed material.

14. The method of any one of the preceding claims, wherein the liquid comprising the organofluorine is a liquid foam comprising the organofluoride.

15. An organofluorine captured material formed by the method of any one of the preceding claims.

16. The organofluorine captured material of claim 15, wherein the organofluorine captured material is pavement and/or construction material.

17. A method of capturing an organohalogen from a liquid, including the steps of: a) contacting a liquid comprising an organohalogen with a sorbent to form an organohalogen sorbed material; and b) contacting the organohalogen sorbed material with one or more binders to form an organohalogen captured material, to thereby capture the organohalogen from the liquid.

18. The method of claim 17, wherein the organohalogen is selected from the group consisting of an organofluorine, an organochlorine an organobromine, and an organoiodine.