Low temperature decomposition of PFAS in molten alkaline hydroxides

Abstract

A method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), includes grinding two alkaline hydroxides into a fine powder creating an alkaline mixture, the two alkaline hydroxides are present in a molar ratio equivalent to a melting temperature at a eutectic point, obtaining a PFAS in powder form, mixing the alkaline mixture and the PFAS together, and heating the sample to a reaction temperature that is slightly above the eutectic point of the alkaline mixture, wherein the temperature is less than 200 °C.

Description

Atty. Docket No. U-8712TGEN013 FP309AWOLOW TEMPERATURE DECOMPOSITION OF PFAS IN MOLTEN ALKALINE HYDROXIDES CROSS-REFERENCE TO RELATED APPLICATION

[0001] This application claims priority to and the benefit under 35 U.S.C. § 119(e) of U.S.Provisional Application No. 63 / 737,987, filed on December 23, 2024, entitled "LOW TEMPERATURE DECOMPOSITION OF PFAS IN MOLTEN ALKALINE HYDROXIDES," the disclosure of which is hereby incorporated herein by reference in its entirety.FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to methods for defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), and more particularly to defluorination and degradation methods for PFAS in low temperature conditions conducted in a molten mixture of alkaline hydroxides while minimizing the production of secondary waste products and pollutants.BACKGROUND

[0003] Per- and poly-fluoroalkyl substances (PFAS), also known as "forever chemicals", are an emerging class of pollutants widely present in surface / ground waters and soils. These compounds have been used for over 60 years in hundreds of industrial applications and consumer products [e.g., carpet, apparel, upholstery, cookware, food wrappers, and aqueous fire-fighting foams (AFFFs)]. The term "forever chemicals" reflects the high chemical stability of PFAS, which renders them highly resistant to hydrolysis, biodegradation, metabolism, photolysis (sunlight), and other degradation processes. Due to the toxicity and tendency to bioaccumulate, the United States Environmental Protection Agency (EPA) has prioritized them astop unregulated contaminants. Thechemical stability of PFAS compoundsisowed to the stable carbon-fluorine bonds in their structure. The U.S. and European countries have begun to ban the manufacturing and use of many PFAS, but efforts to remediate the global spread of PFAS will likely take several decades.

[0004] Current methods for treatment of PFAS include thermolysis, pyrolysis in an inert atmosphere or combustion in the presence of oxygen, to destroy the PFAS molecules. Thermolysis can lead to inefficient degradation and generation of secondary pollutants. During thermolysis, many volatile PFAS compounds, especially those with shorter carbon chains (less than seven carbons), can escape into the atmosphere along with vapor emissions. These volatiles maybe the original PFAS compounds or byproducts from incomplete thermal decomposition. The byproducts include short -chain (between four to seven carbons) andultrashort-chain (between two and three carbon chains) perfluoroalkanes and alkenes, along with non-PFAS fluorocarbons. The release of these volatile compounds into the environment creates further pollution concerns. Given the high thermal stability of PFAS, thermolysis is generally not an effective method for complete destruction. Even at temperatures exceeding 800°C, full decomposition cannot be guaranteed. Therefore, thermolysis is not ideal for defluorination, which is crucial for the detoxification of PFAS.SUMMARY OF THE DISCLOSURE

[0005] According to one aspect of the present disclosure, a system for defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS) includes a reaction vessel, an alkaline mixture disposed within the reaction vessel, the alkaline mixture includes two alkaline hydroxides present in a molar ratio correspondingto around a eutectic melting point temperature of the alkaline mixture, solid PFAS disposed within the reaction vessel and in contact with the alkaline mixture, a heating element thermally coupled to the reaction vessel and configured to maintain the reaction vessel at a reaction temperature above the eutectic melting point temperature of the alkaline mixture.

[0006] According to another aspect of the present disclosure, an apparatus for treating an orga nofluorine compound in mild conditions, includes, a vessel, a powdered mixture disposed within the vessel, the powdered mixture comprising sodium hydroxide in a first molar equivalent between 40 and 60, and potassium hydroxide in a second molar equivalent between 40 and 60, a powdered organofluorine compound disposed withinthe vessel and in contact with the powdered mixture, a heating element operatively coupled to the vessel and configured to maintainthe powdered mixture andthe powdered organofluorine at a reaction temperature between room temperature and 300 °C for a reaction duration of at least 2 hours.

[0007] Accordingto yet another aspect of the present disclosure, a method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), includes grinding two alkaline hydroxides into a fine powder creating an alkaline mixture, the two alkaline hydroxides are present in a molar ratio equivalentto a melting temperature at a eutectic point, obtaininga PFAS in powder form, mixing the alkaline mixture and the PFAS together, and heating the sample to a reaction temperature that is slightly above the eutectic point of the alkaline mixture, wherein the temperature is less than 300 °C.

[0008] According to another aspect of the present disclosure, a method of treating an orga nofluorine compound in mild conditions, includes obtaining a mixture of sodium hydroxide and potassium hydroxide at a molar ratio of around 51:49 in a powder, mixing the mixture of sodium hydroxide and potassium hydroxide with a powdered form of the orga nofluorine compound, heatingthe sample to a reaction temperature to between room temperature and 300 °C, and reacting of the organofluorine compound for at least 2 hours.

[0009] These and other features, advantages, and objects of the present disclosure will be further understood and appreciated by those skilled in the art by reference to the following specification, claims, and appended drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0010] In the drawings:

[0011] FIG. 1 is an illustration of several fluorine-19 nuclear magnetic resonance (19F-NMR) spectra in dimethyl sulfoxide-d6of the reaction progress of perfluorooctanesulfonic acid (PFOS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C, according to aspects of the present disclosure;

[0012] FIG. 2 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum in deuterium oxide of the reaction of perfluorooctanesulfonic acid (PFOS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C at 24 hours, according to aspects of the present disclosure;

[0013] FIG. 3 is a linear fit for the first order kinetics of the degradation of perfluoroocta nesulfonicacid (PFOS) by sodium hydroxide and potassium hydroxide ata molar ratio of 51:49 at 173 °C, according to aspects of the present disclosure;

[0014] FIG. 4 is a linearcalibrationcurvefor the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for varying concentrations of fluoride ions in a reaction solution of perfluorooctanesulfonic acid (PFOS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49, according to aspects of the present disclosure;

[0015] FIG. 5 is a linearcalibration curve usinga standard addition method forthe integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorooctanesulfonic acid (PFOS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49, accordingto aspects of the present disclosure;

[0016] FIG. 6 is a line graph showingthe percent of fluoride recovery and the degradation of perfluorooctanesulfonic acid (PFOS) for the reaction of PFOS with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 dependent on time, according to aspects of the present disclosure;

[0017] FIG. 7 is an illustration of several fluorine-19 nuclear magnetic resonance (19F-NMR) spectra in dimethyl sulfoxide-d6of the reaction progress of perfluorobutane sulfonic acid (PFBS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C, according to aspects of the present disclosure;

[0018] FIG. 8 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum in deuterium oxide of the reaction of perfluorobutane sulfonic acid (PFBS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C at 24 hours, according to aspects of the present disclosure;

[0019] FIG. 9 is a linear fit for the first order kinetics of the degradation of perfluorobutane sulfonicacid (PFBS) by sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C, according to aspects of the present disclosure;

[0020] FIG. 10 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between perfluorobutane sulfonic acid (PFBS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49, accordingto aspects of the present disclosure;

[0021] FIG. 11 is an illustration of several fluorine-19 nuclear magnetic resonance (19F-NMR) spectra in dimethyl sulfoxide-d6of the reaction progress of perfluorohexanesulfonic acid (PFHxS) with sodium hydroxideand potassium hydroxide ata molarratio of 51:49 at 173 °C, according to aspects of the present disclosure;

[0022] FIG. 12 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum in deuterium oxide of the reaction of perfluorohexanesulfonic acid (PFHxS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C at 24 hours, according to aspects of the present disclosure;

[0023] FIG. 13 is a linear fit for the first order kinetics of the degradation of perfluorohexanesulfonic acid (PFHxS) by sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C, according to aspects of the present disclosure;

[0024] FIG. 14 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrumfor the reaction between perfluorohexanesulfonic acid (PFHxS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49, accordingto aspects of the present disclosure;

[0025] FIG. 15 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum in deuterium oxide of the residual product of the reaction of perfluorohexanesulfonic acid (PFHxS) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C at 24 hours, according to aspects of the present disclosure;

[0026] FIG. 16 is an image of the result of grinding a mixture of polyvinylidenefluoride (PVDF) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at room temperature, according to aspects of the present disclosure;

[0027] FIG. 17 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum in deuterium oxide of the reaction of polyvinylidene fluoride (PVDF) with sodium hydroxide and potassium hydroxide at a molar ratioof 51:49 at room temperature at 2 hours, according to aspects of the present disclosure;

[0028] FIG. 18 is a linear calibration curve using a standard addition method for the integrated area of the fluoride ion peak on a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum for the reaction between polyvinylidene fluoride (PVDF) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49, accordingto aspects of the present disclosure; and

[0029] FIG. 19 is an illustration of a fluorine-19 nuclear magnetic resonance (19F-NMR) spectrum in deuterium oxide of the reaction of polytetrafluoroethylene (PTFE) with sodium hydroxide and potassium hydroxide at a molar ratio of 51:49 at 173 °C at 24 hours, according to aspects of the present disclosure.DETAILED DESCRIPTION

[0030] The present illustrated embodiments reside primarily in combinations of method stepsand apparatus components related to defluorination and degradation methods for per- and poly-fluoroalkyl substances (PFAS) in low temperature conditions conducted in a molten mixture of alkaline hydroxides while minimizingthe production of secondary waste products and pollutants. Accordingly, the apparatus components and method steps have been represented, where appropriate, by conventional symbols in the drawings, showing only those specific details that are pertinent to understandingthe embodiments of the present disclosure so as not to obscure the disclosure with details that will be readily apparent tothose of ordinary skill in the art having the benefit of the description herein. Further, like numerals in the description and drawings represent like elements.

[0031] For purposes of description herein, the terms "upper," "lower," "right," "left," "rear," "front," "vertical," "horizontal," and derivatives thereof, shall relate to the disclosure as oriented in FIG. 1. Unless stated otherwise, the term "front" shall refer to a surface of the device closest to an intended viewer, and the term "rear" shall referto a surface of the device furthest from the intended viewer. However, it is to be understood that the disclosure may assume various alternative orientations, except where expressly specified to the contrary. It is also to be understood that the specific devices and processes illustrated in the attached drawings, and described in the following specification are simply exemplary embodiments of the inventive concepts defined in the appended claims. Hence, specific dimensions a nd other physical characteristics relatingto the embodiments disclosed herein are not to be considered as limiting, unless the claims expressly state otherwise.

[0032] The terms "including," "comprises," "comprising," or any other variation thereof, are intended to covera non-exclusive inclusion, such thata process, method, article, orapparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element preceded by "comprises a . . . " does not, without more constraints, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0033] The present disclosure relates to a method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS).The method includes grinding two alkaline hydroxides into a fine powder creating an alkaline mixture, the two alkaline hydroxides may be present around a molar ratio equivalent to a melting temperature at a eutectic point. A PFAS in powderform is then mixed with thealkaline mixture.Thesample isthen heatedtoa reaction temperature that is slightly above the eutectic point of the alkaline mixture. The temperature may be less than 200 °C.

[0034] The present disclosure further relates to the defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS) using a mixture of alkaline hydroxides at low temperatures and breakingthe substances down into ions such as fluoride ions (F ) or small molecules. In some examples, the alkaline hydroxides mixture may act as a base. The target PFAS include but are not limited to perfluorooctanesulfonic acid (PFOS),perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonic acid (PFBS), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), perfluorooctanoic acid (PFOA), pefluorononanoicacid (PFNA), and an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™). In some implementations, the target substances may include other orga nofluorine compounds or polymers. These methods of defluorination and degradation are conducted under mild conditions, such as ambient pressure and relatively low temperatures around and less than 200°C, without the use of intense reaction conditions involving high-energy UV light, electron beams, plasma, or oxygen free (e.g. under argon protection) as required for photocatalytic reduction. In some examples, the mixture of alkaline hydroxides is sodium hydroxide (NaOH) and potassium hydroxide (KOH). In some examples, the mixture of NaOH and KOH may be around the eutectic point. In still some further examples, the mixture of NaOH and KOH is in a molar ratio of about 51:49.

[0035] The composition of NaOH and KOH in a molar ratio of 51:49 corresponds to the eutectic point in the phase diagram, providingthe lowest melting point of the binary system (i.e. 170 °C) compared to the significantly higher melting points of the individual components, NaOH: 319 °C; KOH: 405 °C. The sameeutecticcompositionand resulting lower melting point also apply to mixtures of other alkaline hydroxides, such as lithium hydroxide (LiOH), rubidium hydroxide (RbOH), and cesium hydroxide (CsOH), either in combination with each other or in a combination with NaOH and KOH. Potential alkaline mixtures include, but are not limited to, NaOH and KOH, NaOH and LiOH, NaOH and RbOH, NaOH and CsOH, KOH and LiOH, KOH and RbOH, KOH and CsOH, LiOH and RbOH, LiOH and CsOH, and RbOH a nd CsOH .The reaction may be run as a neat reaction, where the chemical reaction takes place without the use of a solvent. In some aspects, complete degradation of PFAS may be achieved within 20 hours. In some further aspects, the temperature may be room temperatu re.

[0036] Without wishingto be bound by theory, the reaction between PFAS and a mixture of alkaline hydroxides may breakthe carbon-fluorine (C-F) bond and may liberate fluoride ions (F ). Further, the reaction may break the carbon-carbon (C-C) bond and may produce small fluorine-free molecules. Other methods prove the difficulty of the degradation of PFAS due to a high thermal stability of these molecules. The high thermal stability is attributed to the strength ofthe C-F bond, resulting from a bond energy of 485 kJ / mol. The C-F bond is much stronger than bonds found in some other common organic molecules, such as C-C bond (347 kJ / mol) and carbon-hydrogen (C-H) bond (413 kJ / mol). Other methods of defluorinationand / or degradation of PFAS often use intense reaction conditions involving high temperatures (e.g., >500 °C), high-energy UV light, electron beams, or plasma, require high energy inputs, orgenerate secondary pollutants. The method of the current disclosure may not only be effective in achieving complete defluorination but may also be environmentally sustainable by minimizing the production of secondary waste or pollutants, which may help to reduce the energy consumption and overall cost relevant to safety and quality control.

[0037] The degradation of a PFAS in the presence of a molten mixture of two alkaline hydroxides, for example, NaOH and KOH, with a molar ratio of 51:49 may be modeled as first (1st) order if the concentration of the base is in excess compared to the PFAS. In excess may be defined at a molar ratio of around 100:1 as presented herein. A reaction rate constant k may be calculated from the linear 1storder kinetics fitting. The 1storder reaction may be defined using equation (I):C = Coe~kt(I)wherein Cis the concentration of the PFAS measured at a given reaction time t, Cois the initial concentration of the PFAS at time zero, k is the reaction rate constant (or efficient). The reaction rate constant k, has units of 1 / time (e.g., 1 / hour). Equation (I) may be rearranged to give equation (II):In A = -kt (II)cowherein C is the concentration of PFAS measured at a given reaction time t, Cois the initial concentration of the PFAS at time zero, k is the reaction rate constant. Equation (II) implies cthata plot of ln(— ) vs. t mayfit intoa linearrelationship.Theslopeofthe linearrelationship oobtained from a linear fitting would give the value of the reaction rate constant k.

[0038] A reaction progress of the present disclosure may be tracked using nuclear magnetic resonance (NMR). An integral area of NMR peaks may be used to determine the concentration of a chemical (ions or molecules) being measured. This method relies on a principle that peak intensity or area is proportional to an analyte concentration; thus a linear relationship that serves as a calibration curve may be developed. The reaction progress of a defluorination reaction may accordingly be quantified using fluorine-19 nuclear magnetic resonance (19F- NMR) measurements to quantify the amount of free fluoride ions in the reaction.

[0039] During a defluorination reaction, the reaction solution may continually change regardingthe concentration ofa PFAS compound and a base, as well as other characteristicsof the solution. Therefore, a calibration curve established under fixed conditions cannot be directly applied forthe quantitative analysis of fluorine ions in real reaction samples. Standard addition method, which is typical in analytical chemistry, used to accurately determine the concentration of an analyte within complex samples, especially where matrix effects could interfere with results may be used. The procedure may proceed by measuring the initial response (here a fluoride ion peak around -122 ppm using19F-NMR analysis) of the sample containingthe unknown concentrationoffluoride ions. Subsequently, known concentrations of fluoride ion, which may be added to the solution as sodium fluoride (NaF), may be added incrementallyto separate portionsofthe sample. It may be appropriate, aftereach addition, to measure the19F-NMR spectrum multiple times, to give an average value of an integral area under the fluoride ion peak. This approach may effectively account for any interference from a sample matrix, allowingfora more accurate determination of fluoride ion in the solution at a given time within a defluorination reaction compared to a total fluorine initially present from a starting concentration of PFAS. This measurement may yield a fluoride recovery efficiency (%), by plotting the concentration of fluoride ions at a given time over the total initial fluorine present against the time of a reaction. The fluoride recovery efficiency may be used to assess the effectiveness of the defluorination and degradation of a PFAS.EXAMPLES

[0040] Example 1: Defluorination and Degradation of Perfluorooctanesulfonic Acid (PFOS)

[0041] The bases sodium hydroxide (NaOH) and potassium hydroxide (KOH) were reacted as a mixture in the presence of perfluorooctanesulfonic acid (PFOS). KOH and NaOH pellets were finely ground in a porcelain mortar-pestle. Afine powderof KOH (13.74 g, 0.24 mol), a fine powder of NaOH (10.19 g, 0.25 mol), and PFOS (1.30 g, 0.0024 mol) were taken in a mortarpestle and mixed thoroughly to form a reaction mixture. The mixed reaction mixture was transferred into a 50 mL polypropylene tube and stored for further use. Several amounts of approximately 1 g of the solid mixture were placed in individual alumina crucibles and transferred to a preheated oven maintained at 173 °C. The reaction mixtures were maintained at the same temperature for varying durations, ranging from 0 to 24 hours, to measure the reaction progress. The reaction was conducted at 173 °C, ensuringthe mixture of NaOH and KOH (51:49) remained in a molten state.

[0042] FIG. 1 shows the reaction progress of PFOS with NaOH and KOH as described above.To monitor the reaction progress, at a designated time, the mixture was allowed to coolnaturally to room temperature and was then dispersed in 5 mL of dimethyl sulfoxide. A 100 pL aliquot of each dispersion was transferred to an NMR tube, followed by the addition of 400 pL of dimethyl sulfoxide-d6(DMSO-d6). The residual PFOS content at different time intervalswas analyzed using19F-NMR spectroscopy with a 400 MHz instrument. Asshown in FIG. 1, the PFOS peaks decreased and after 20 hours no fluorine peaks were observed, indicating complete defluorination and degradation of PFOS. Any fluoride ions generated in the degradation reaction described above are not soluble in DMSO-d6, but the fluoride ions are soluble in deuterium oxide (D2O). FIG. 2 showsthe reaction product in D2O after 24 hours of reaction. The fluoride peak detected around -122 ppm suggests effective defluorination, producing fluoride ions due to the cleavage of the carbon-fluorine (C-F) bonds, mineralizing PFOS into fluoride ions within the testing time at 173 °C.

[0043] The degradation of PFOS as described in the reaction herein follows a first (1st) order reaction kinetics. The reaction kinetics may be modeled as 1storder since the concentration of the bases, for example NaOH and KOH, is in excess (e.g. 100:1). The reaction rate constant k may be calculated. The 1storder reaction may be defined using equation (I):C = Coe~kt(I)

[0044] wherein C is the concentration of PFOS measured at a given reaction time t, Cois the initial concentration of PFOS at time zero, k is the reaction rate constant (or efficient). The reaction rate constant k has units of 1 / time. Equation (I) may be rearranged to give equation (II):In A = -kt (II)co

[0045] wherein C is the concentration of PFOS measured at a given reaction time t, Cois the initial concentration of PFOS at time zero, k is the reaction rate constant. Equation (II) may cimply that a plot of ln(— ) vs. t may fit into a linear relationship. The slope of the linear relationship obtained from a linearfitting would give the value of the reaction rate constant k.

[0046] FIG. 3 showsthe lstorderkineticsfittingofthedata obtainedfromthedegradationof PFOS by NaOH and KOH at a molar ratio of 51:49 at 173 °C. The concentration of the PFOS at a given time was determined by integration of peaks using19F-NMR. As pea kintensity or area within an NMR spectrum is proportional to an analyte concentration, the area under the curve of an analyte at a given time A and the area under the curve for an analyte at time zero AoA Cwould resultin — beingofequivalentvalueas— . Theslopeofthefitted linear model yielded AQ CQthe reaction constant kfor this specific reaction and temperature, which yielded 0.2177 h1.

[0047] The integral area of NMR peaks may be used to determine the concentration of a chemical being measured as an analyte. This relationship relies on the principle that peak intensity or peak area is proportional to the analyte concentration, creating a linear relationship that serves as a calibration curve. To verify this principle,19F-NMR measurements were executed with a series of solutions spiked with varying concentrations of fluoride (F ) ions. Referring to FIG. 4, a linear calibration curve was generated by plotting the integral area of the fluoride ion peak at -122 ppm in the19F-NMR spectrum in D2O as a function of the spiked concentrationsof sodium fluoride (Na F). The spiked concentration was in the range of 0 to 50 mM. The linearity of the plot may imply the feasibility of using19F-NMR spectrometry for the quantitative analysis of fluoride ions produced in the defluorination reactions described herein.

[0048] During the defluorination process, the reaction solution may continually change with time regarding the concentration of PFOS, the concentration of the bases, and potentially other metrics of the solution. Quantitative analysis of fluoride ions was performed using a standard addition method formore accurate measurements. The integral area of the fluoride peak (-122 ppm) in the19F-NMR spectrum was plotted as a function of the spiked concentrations of sodium fluoride (NaF), generating a linear curve. By extrapolating the line down to Y=0 (i.e., the zero value of integral area of fluoride peak), the interception thus obtained on the X-axis corresponds to the concentration of fluoride ion in the reaction sample. This standard addition approach effectively accounts for any interference from the sample matrix, a I lowing for a more accurate determination of fluoride ion concentration. FIG.5 shows standard addition measurements applied to the analysis of fluoride ions generated after a 24 h reaction at 173 °C of PFOS with NaOH and KOH at a molar ratio of 51:49. The concentration values marked represent the fluoride concentrations in the NMR solution, which are diluted 10X from the reaction solution of the bases. The total fluorine available from the initial PFOS concentration was 719.4 mM. FIG. 5 provides a high level of linearity of fitting, enabling a reliable determination of fluoride ion concentration.

[0049] Referring now to FIG. 6, using the model from the standard addition measurements, the amount of fluoride ion calculated may then be compared to the total fluorine initiallypresentfrom the starting concentrationofPFOS, yieldingthe fluoride recovery efficiency (%) at varying reaction times. FIG. 6 shows the fluoride recovery efficiency (%) dependent on time of the reaction of the degradation of PFOS with NaOH and KOH at a molar ratio of 51:49, resulting in a final fluoride recovery of 98.4%. Given the standard deviation of the measurements, the final level of fluoride recovery may reasonably suggest full or complete defluorination of PFOS. Further, FIG. 6 shows the time-dependent degradation of PFOS with the corresponding fluoride recovery at the different tested time intervals.

[0050] Example 2: Defluorination and Degradation of Perfluorobutane sulfonic acid (PFBS)

[0051] The bases sodium hydroxide (NaOH) and potassium hydroxide (KOH) were reacted as a mixture in the presence of perfluorobutane acid (PFBS). KOH and NaOH pellets were finely ground in a porcelain mortar-pestle. Afine powderof KOH (13.74 g, 0.24 mol), a fine powder of NaOH (10.19 g, 0.25 mol), and PFBS (0.0024 mol) were taken in a mortar-pestle and mixed thoroughly. The mixed reaction mixture was transferred into a 50 mL polypropylene tube and stored for further use. Several amountsofapproximatelylg of the solid mixture were placed in individual alumina crucibles a nd transferred to a preheated oven maintained at 173 °C. The reaction mixtures were maintained at the same temperature for varying durations, ranging from 0 to 24 hours, to measure the reaction progress. The reaction was conducted at 173 °C, ensuring the mixture of NaOH and KOH (51:49) remained in a molten state.

[0052] FIG. 7 shows the reaction progress of PFBS with NaOH and KOH as described above.To monitor the reaction progress, at a designated time, the mixture was allowed to cool naturally to room temperature and was then dispersed in 5 mL of dimethyl sulfoxide. A 100 pL aliquot of each dispersion was transferred to an NMR tube, followed by the addition of 400 pL of dimethyl sulfoxide-d6(DMSO-d6). The residual PFBS content at different time intervalswas analyzed using19F-NMR spectroscopy with a 400 MHz instrument. Asshown in FIG. 7, the PFBS peaks decreased, and after 20 hours, no fluorine peaks were observed, indicating complete or near-complete defluorination and degradation of PFBS. Any fluoride ionsgenerated in the degradation reaction described above are not soluble in DMSO-d6, but the fluoride ions are soluble in deuterium oxide (D2O). FIG. 8 shows the reaction product in D2O after 24 hours of reaction. The fluoride peak detected around -122 ppm suggests effective defluorination, producing fluoride ions due to the cleavage of the carbon-fluorine (C-F) bonds, mineralizing PFBS into fluoride ions within the testing time at 173 °C.

[0053] The degradation of PFBS as described in the reaction herein follows a first (1st) order reaction kinetics. The reaction kinetics may be modeled as 1storder since the concentration ofthe bases, forexample NaOH and KOH, is in excess (e.g. 100:1). The reaction kinetics model to determine the reaction constant k is found in Example 1 using equations (I) and (II). FIG. 9 showsthe lstorder kinetics fittingof the data obtained from the degradation of PFBS by NaOH and KOH at a molar ratio of 51:49 at 173 °C. The concentration ofthe PFBS at a given time was determined by integration of peaks using19F-NMR. As peak intensity or area within an NMR spectrum is proportional to an analyte concentration, the area under the curve of an analyte at a given time A and the area under the curve for an analyte at time zero Aowould A Cresult in — beingof equivalent va I ue as—, where C is the concentration of PFBS measured at AoCoa given reaction time t, and Cois the initial concentration of PFBS at time zero. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature, which yielded 0.2357 h1.

[0054] During the defluorination process, the reaction solution may continually change with time regarding the concentration of PFBS, the concentration of the bases, and potentially other metrics of the solution. Quantitative analysis of fluoride ions was performed using a standard addition method formore accurate measurements. The integral area of the fluoride peak (-122 ppm) in the19F-NMR spectrum was plotted as a function of the spiked concentrations of sodium fluoride (NaF), generating a linear curve. By extrapolatingthe line down to Y=0 (i.e., the zero value of integral area of fluoride peak), the interception thus obtained on the X-axis corresponds to the concentration of fluoride ion in the reaction sample. This standard addition approach effectively accounts for any interference from the sample matrix, a I lowing for a more accurate determination of fluoride ion concentration. FIG.10 shows standard addition measurementsappliedto the ana lysis of fluoride ions generated after a 24 h reaction at 173 °C of PFBS with NaOH and KOH at a molar ratio of 51:49. The concentration values marked represent the fluoride concentrations in the NMR solution, which are diluted 10X from the reaction solution of the bases. The total fluorine available from the initial PFBS concentration was 190.4 mM. FIG. 10 providesa high level of linearity of fitting, enabling a reliable determination of fluoride ion concentration. Using the model from the standard addition measurements, the amount of fluoride ion calculated may then be compared to the total fluorine initially present from the starting concentration of PFBS,yielding the fluoride recovery efficiency (%) at varying reaction times, resulting in a final fluoride recovery of 98.2%.

[0055] Example 3: Defluorination and Degradation of Perfluorohexanesulfonic acid (PFHxS)

[0056] The bases sodium hydroxide (NaOH) and potassium hydroxide (KOH) were reacted as a mixture in the presence of perfluorohexanesulfonic acid (PFHxS). KOH and NaOH pellets were finely ground in a porcelain mortar-pestle. A fine powder of KOH (13.74 g, 0.24 mol), a fine powder of NaOH (10.19 g, 0.25 mol), and PFHxS (0.0024 mol) were taken in a mortarpestle and mixed thoroughly. The mixed reaction mixture was transferred into a 50 mL polypropylene tube and stored for further use. Several amounts of approximately 1 g of the solid mixture were placed in individual alumina cruciblesand transferred to a preheated oven maintained at 173 °C. The reaction mixtures were maintained at the same temperature for varyingdurations, ranging from Oto 24 hours, to measurethe reaction progress. The reaction was conducted at 173 °C, ensuring the mixture of NaOH and KOH (51:49) remained in a molten state. The reaction was carried out in a sealed condition.

[0057] FIG. 11 showsthe reaction progress of PFHxS with NaOH and KOH asdescribed above.To monitor the reaction progress, at a designated time, the mixture was allowed to cool naturally to room temperature and was then dispersed in 5 mL of dimethyl sulfoxide. A 100 pL aliquot of each dispersion was transferred to an NMR tube, followed by the addition of 400 pL of dimethyl sulfoxide-d6(DMSO-d6). The residual PFHxS content at different time intervalswas analyzed using19F-NMR spectroscopy with a 400 MHz instrument. Asshown in FIG. 11, the PFHxS peaks decreased, and after 16 hours, no fluorine peaks were observed, indicating complete defluorination and degradation of PFHxS. Any fluoride ions generated in the degradation reaction described above are not soluble in DMSO-d6, but the fluoride ions are soluble in deuterium oxide (D2O). FIG. 12 shows the reaction product in D2O after 24 hours of reaction. The fluoride peak detected around -122 ppm suggests effective defluorination, producing fluoride ions due to the cleavage of the carbon-fluorine (C-F) bonds, mineralizing PFHxS into fluoride ions within the testing time at 173 °C.

[0058] The degradationof PFHxS as described in the reaction herein followsa first (1st) order reaction kinetics. The reaction kinetics may be modeled as 1storder since the concentration ofthe bases, forexample NaOH and KOH, is in excess (e.g. 100:1). The reaction kinetics model to determine the reaction constant k is found in Example 1 usingequations(l)and (II). FIG. 13 shows the 1storder kinetics fitting of the data obtained from the degradation of PFHxS byNaOH and KOH at a molar ratio of 51:49 at 173 °C. The concentration ofthe PFHxS at a given time was determined by integration of peaks using19F-NMR. As peakintensityorarea within an NMR spectrum is proportional to an analyte concentration, the area under the curve of an analyte at a given time A and the area under the curve for an analyte at time zero Aowould A Cresult in — beingof equivalent value as where C is the concentration of PFHxS measured A0at a given reaction time t, and Cois the initial concentration of PFHxS at time zero. The slope of the fitted linear model yielded the reaction constant k for this specific reaction and temperature, which yielded 0.3738 h1.

[0059] During the defluorination process, the reaction solution may continually change with time regarding the concentration of PFHxS, the concentration of the bases, and potentially other metrics of the solution. Quantitative analysis of fluoride ions was perfo rmed using a standard addition method formore accurate measurements. The integral area of the fluoride peak (-122 ppm) in the19F-NMR spectrum was plotted as a function of the spiked concentrations of sodium fluoride (NaF), generating a linear curve. By extrapolatingthe line down to Y=0 (i.e., the zero value of integral area of fluoride peak), the interception thus obtained on the X-axis corresponds to the concentration of fluoride ion in the reaction sample. This standard addition approach effectively accounts for any interference from the sample matrix, a I lowing for a more accurate determination of fluoride ion concentration. FIG.14 shows standard addition measurementsappliedto the ana lysis of fluoride ions generated after a 24 h reaction at 173 °C of PFHxS with NaOH and KOH at a molar ratio of 51:49. The concentration values marked represent the fluoride concentrations in the NMR solution, which are diluted 10X from the reaction solution of the bases. The total fluorine available from the initial PFHxS concentration was 257.9 mM. FIG. 14 providesa high level of linearity of fitting, enabling a reliable determination of fluoride ion concentration. Using the model from the standard addition measurements, the amount of fluoride ion calculated may then be compared to the total fluorine initially present from the starting concentration of PFHxS, yielding the fluoride recovery efficiency (%) at varying reaction times, resulting in a final fluoride recovery of 47.3%.

[0060] The low fluoride recovery observed by standard addition of sodium fluoride may be attributed to two possible reasons: one is that some fluorine-containing byproducts are generated but they are not soluble in DMSO, this would also show a lack of peaks shown inthe19F-NMR spectra as shown in Figure 12 which confirms the complete disappearance of PFHxS peaks; the other is that there may be fluorine-containing byproducts generated that are volatile, and therefore evaporated during the reaction. Referring now to FIG. 15, to confirm the first possibility, the19F-NMR spectral measurement in D2O was conducted at a higher scan rate (e.g. a longer duration) to identify any fluorine-containing byproducts generated at low concentrations. As shown in FIG. 15, additional fl uoride signals were detected compared to FIG. 12, confirmingthe formation of side products alongside inorganic fluoride ions. This may ultimately explain the low fluoride recovery observed using the standard addition method. Toachieve full recovery of fluoride ion (i.e., full mineralization of original PFAS), a long reaction time and a sealed reaction system maybe needed for practical systems.

[0061] Example 4: Defluorination and Degradation of polyvinylidene fluoride (PVDF)

[0062] The bases sodium hydroxide (NaOH) and potassium hydroxide (KOH) were reacted as a mixture in the presence of polyvinylidenefluoride (PVDF). KOH and NaOH pellets were finely ground in a porcelain mortar-pestle. Afine powderof KOH (13.74 g, 0.24 mol), a fine powder of NaOH (10.19 g, 0.25 mol), and PVDF (0.0024 mol) were taken in a mortar-pestle and mixed thoroughly. Upon grinding the PVDF powderwith the base mixture at room temperature, a rapid change in color was observed asshown in FIG. 16. The reaction mixture was maintained at room temperature for 2 hours. The rapid color change may indicate a rapid degradation reaction. The reaction mixture was measured after 2 hours of reaction at room temperature using19F-NMR spectroscopy on a 400 MHz instrument in a deuterium oxide (D2O) solvent. FIG. 17 shows a strong fluoride peak near -122 ppm, which may suggest effective defluorination producing fluoride ions, due to the cleavage of the carbon -fluorine (C-F) bonds present in PVDF polymer. This implies that the base mixture used in the experiment can effectively break the C-F bonds even at room temperature, mineralizing PVDF into fluoride ions within the testing time frame. It is expected that the degradation may be expedited dramatically if the reaction was conducted at an elevated temperature.

[0063] During the defluorination process, the reaction solution may continually change with time regarding the concentration of PVDF, the concentration of the bases, and potentially other metrics of the solution. Quantitative analysis of fluoride ions was performed using a standard addition method for more accurate measurements. The integral area of fluoride peak (-122 ppm) in the19F-NMR spectrum was plotted as a function of the spikedconcentrations of sodium fluoride (NaF), generating a linear curve. By extrapolating the line down to Y=0 (i.e., the zero value of integral area of fluoride peak), the interception thus obtained on the X-axis corresponds to the concentration of fluoride ion in the reaction sample. This standard addition approach effectively accounts for any interference from the sample matrix, a I lowing for a more accurate determination of fluoride ion concentration. FIG.18 shows standard addition measurements applied to the analysis of fluoride ions generated after a 2 h reaction at room temperature of PVDF with NaOH and KOH at a molar ratio of 51:49. The concentration values marked represent the fluoride concentrations in the NMR solution, which are diluted 10X from the reaction solution of the bases. The total fluorine available from the initial PVDF concentration was 51.32 mM. FIG. 18 provides a high level of linearity of fitting, enabling a reliable determination of fluoride ion concentration. Usingthe model from the standard addition measurements, the amount of fluoride ion calculated may then be compared to the total fluorine initially present from the starting concentration of PVDF, yielding the fluoride recovery efficiency (%) at varying reaction times, resultingin a final fluoride recovery of 66.2%. FIG. 18 indicates that complete fluoride recovery was not achieved. Longer reaction times or higher temperatures may help achieve the complete defluorination (mineralization), resulting in full recovery of the fluoride ions.

[0064] Example 5: Defluorination and Degradation of Polytetrafluoroethylene (PTFE)

[0065] The bases sodium hydroxide (NaOH) and potassium hydroxide (KOH) were reacted as a mixture in the presence of polytetrafluoroethylene (PTFE). KOH and NaOH pellets were finely ground in a porcelain mortar-pestle. Afine powderof KOH (13.74 g, 0.24 mol), a fine powder of NaOH (10.19 g, 0.25 mol), and PTFE (0.0024 mol) were taken in a mortar-pestle and mixed thoroughly. The mixed reaction mixture was transferred into a 50 mL polypropylene tube and stored for further use. Several amounts of approximately 1 g of the solid mixture were placed in individual alumina cruciblesand transferred to a preheated oven maintained at 173 °C. The reaction mixtures were maintained at the same temperature for varyingdurations, ranging from Oto 24 hours, to measure the reaction progress. The reaction was conducted at 173 °C, ensuring the mixture of NaOH and KOH (51:49) remained in a molten state. The reaction was carried out in a sealed condition.

[0066] The residual PTFE content was analyzed using19F-NMR spectroscopy with a 400 MHz instrument. FIG. 19 shows the reaction progress of PTFE with NaOH and KOH as described above after 24 hours. Multiple peaks were observed in the19F-NMR spectra in a D2O solvent,potentially indicating the formation of water-soluble fl uorine-containing byproducts from the degradation of PTFE in the molten base treatment. However, the absence of a peak near -122 ppm may indicate that no anionicfluoride wasformed during the reaction. A longer reaction time and / or using a smaller particle size of PTFE (thus increasing reaction surface area) may help facilitate the defluorination reaction.

[0067] The will be understood by one having ordinary skill in the art that construction of the described disclosure and other components is not limited to any specific material. Other exemplary embodiments of the disclosure disclosed herein may be formed from a wide variety of materials, unless described otherwise herein.

[0068] According to one aspect of the present disclosure a method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS) includes grinding two alkaline hydroxides into a fine powder creating an alkaline mixture, the two alkaline hydroxides are presentin a molar ratioequivalenttoa meltingtemperature at a eutectic point, obtaininga PFAS in powder form, mixing the alkaline mixture and the PFAS together, and heating the sample to a reaction temperature that is slightly above the eutectic point of the alkaline mixture, the temperature is less than 300 °C.

[0069] Accordingto another aspect of the present disclosure, the two alkaline hydroxides are any combination of sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, or cesium hydroxide.

[0070] Accordingto yet another aspect of the present disclosure, the two alkaline hydroxides are sodium hydroxide and potassium hydroxide.

[0071] According to another aspect of the present disclosure, the sodium hydroxide and potassium hydroxide are present in a molar ratio of 51:49.

[0072] Accordingto yet another aspect of the present disclosure, the reaction temperature is less than 200 °C.

[0073] Accordingto yet another aspect of the present disclosure, the reaction temperature is around 173 °C.

[0074] Accordingto anotheraspect ofthe present disclosure, the alkaline mixture is in molar excess of the PFAS.

[0075] According to yet another aspect of the present disclosure, a byproduct of the defluorination is fluoride ions.

[0076] According to another aspect of the present disclosure, a recovery of fluoride ions from said defluorination and degradation is up to 100% recovery.

[0077] According to yet another aspect of the present disclosure, said PFAS is perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonicacid (PFBS), polyvinylidenefluoride (PVDF), polytetrafluoroethylene (PTFE), perfluorooctanoicacid (PFOA), pefluorononanoicacid (PFNA), or an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™).

[0078] According to another aspect of the present disclosure, a method of treating an orga nofluorine compound in mild conditions, includes obtaining a mixture of sodium hydroxide and potassium hydroxide at a molar ratio of around 51:49 in a powder, mixing the mixture of sodium hydroxide and potassium hydroxide with a powdered form of the orga nofluorine compound, heatingthe sample to a reaction temperature to between room temperature and 300 °C, and reacting of the organofluorine compound for at least 2 hours.

[0079] According to yet another aspect of the present disclosure, the reaction temperature is less than 200 °C.

[0080] According to yet another aspect of the present disclosure, an operating pressure of the reaction is ambient pressure.

[0081] According to another aspect of the present disclosure, the reacting of said organofluorine compound is a neat reaction.

[0082] According to yet another aspect of the present disclosure, the reaction temperature is high enough to maintain the mixture of sodium hydroxide and potassium hydroxide in a molten state.

[0083] According to anotheraspectof the present disclosure, the organofluorine compound comprises a per- and poly-fluoroalkyl substance.

[0084] For purposes of this disclosure, the term "coupled" (in all of its forms, couple, coupling, coupled, etc.) generally means the joining of two components (electrical or mechanical) directly or indirectly to one another. Such joining may be stationary in nature or movable in nature. Such joining may be achieved with the two components (electrical or mechanical) and any additional intermediate members being integrally formed as a single unitary body with one another or with the two components. Such joining may be permanent in nature or may be removable or releasable in nature unless otherwise stated.

[0085] It is also important to note that the construction and arrangement of the elements of the disclosure, as shown in the exemplary embodiments, is illustrative only. Although only a few embodiments of the present innovations have been described in detail in this disclosure, those skilled in the art who review this disclosure will readily appreciate that many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departingfrom the novel teachings and advantages of the subject matter recited. For example, elements shown as integrally formed may be constructed of multiple parts, or elements shown as multiple parts may be integrally formed, the operation of the interfaces may be reversed or otherwise varied, the length or width of the structures and / or members or connector or other elements of the system may be varied, the nature or numberof adjustment positions provided between the elements may be varied. It should be noted that the elements and / or assemblies of the system may be constructed from any of a wide variety of materials that provide sufficient strength or durability, in any of a wide variety of colors, textures, and combinations. Accordingly, all such modifications are intended to be included within the scope of the present innovations. Other substitutions, modifications, changes, and omissions may be made in the design, operating conditions, and arrangement of the desired and other exemplary embodiments without departing from the spirit of the present innovations.

[0086] It will be understood thatanydescribed processesorstepswithindescribed processes may be combined with other disclosed processes or steps to form structures within the scope of the present disclosure. The exemplary structures and processes disclosed herein are for illustrative purposes and are not to be construed as limiting.

Claims

What is claimed is:

1. A system for defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), comprising:a reaction vessel;an alkaline mixture disposed within the reaction vessel, wherein the alkaline mixture comprises two alkaline hydroxides present in a molar ratio corresponding to around a eutectic melting point temperature of the alkaline mixture;a solid PFAS disposed within the reaction vessel and in contact with the alkaline mixture;a heating element thermally coupled to the reaction vessel and configured to maintain the reaction vessel at a reaction temperature above the eutectic melting point temperature of the alkaline mixture.

2. The system fordefluorination and degradation of per-and poly-fluoroalkyl substances (PFAS) of claim 1, wherein the reaction temperature is below 300 °C.

3. The system fordefluorination and degradation of per-and poly-fluoroalkyl substances (PFAS) of either one of claims lor 2, wherein the two alkaline hydroxides a re any combination of sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, orcesium hyd roxide.

4. The system fordefluorination and degradation of per-and poly-fluoroalkyl substances (PFAS) of any one of claims 1-3, wherein the two alkaline hydroxides are sodium hydroxide and potassium hydroxide.

5. The system fordefluorination and degradation of per-and poly-fluoroalkyl substances (PFAS) of claim 4, wherein the sodium hydroxide and potassium hydroxide are present in a molar ratio of 51:49.

6. The system fordefluorination and degradation of per-and poly-fluoroalkyl substances (PFAS) of claim 5, wherein the reaction temperature is less than 200 °C.

7. The system fordefluorination and degradation of per-and poly-fluoroalky I substances (PFAS) of any one of claims 1-6, wherein the reaction temperature is 173 °C.

8. The system fordefluorination and degradation of per-and poly-fluoroalky I substances (PFAS) of any one of claims 1-7, wherein the alkaline mixture is in molar excess of the PFAS.

9. The system fordefluorination and degradation of per-and poly-fluoroalky I substances (PFAS) of any one of claims 1-8, wherein a recovery of fluoride ionsfrom said defluorination is up to 100% recovery.

10. The system fordefluorination and degradation of per-and poly-fluoroalky I substances (PFAS) of any one of claims 1-9, wherein a reaction time for said defluorination and degradation is less than 20 hours.

11. The system fordefluorination and degradation of per-and poly-fluoroalky I substances (PFAS) of any one of claims 1-10, wherein said PFAS is perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonic acid (PFBS), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), perfluorooctanoic acid (PFOA), pefluorononanoicacid (PFNA), or an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™).

12. An a pparatusfor treating an orga nofluorine compound in mild conditions, comprising:a vessel;a powdered mixture disposed within the vessel, the powdered mixture comprising sodium hydroxide in a first molarequivalent between 40and 60, and potassium hydroxide in a second molar equivalent between 40 and 60;a powdered organofluorine compound disposed within the vessel and in contact with the powdered mixture;a heating element operatively coupled to the vessel and configured to maintain the powdered mixture and the powdered organofluorine at a reaction temperature between room temperature and 300 °C for a reaction duration of at least 2 hours.

13. The apparatus for treating an orga nofluorine compound in mild conditions of claim 12, wherein the first molar equivalent is 51 and the second molar equivalent is 49.

14. The apparatus fortreating an organofluorine compound in mild conditions of either one of claims 12 or 13, wherein the reaction temperature is less than 200 °C.

15. The apparatus for treating an orga nofluorine compound in mild conditions of anyone of claims 12-14, wherein an operating pressure of the reaction is ambient pressure.

16. The apparatus for treating an orga nofluorine compound in mild conditions of anyone of claims 12-14, wherein the vessel is sealed to the ambient environment.

17. The apparatus for treating an orga nofluorine compound in mild conditions of anyone of claims 12-16, wherein said apparatus is free of a liquid solvent.

18. The apparatus for treating an orga nofluorine compound in mild conditions of anyone of claims 12-17, wherein the organofluorine compound comprises a per- a nd poly-fluoroalkyl substance.

19. The apparatus for treating an orga nofluorine compound in mild conditions of anyone of claims 12-17, wherein the organofluorine compound comprises a fluorinated polymer.

20. The apparatus for treating an organofluorine compound in mild conditions of claim 19, wherein the fluorinated polymer is polyvinylidene fluoride.

21. A method of defluorination and degradation of per- and poly-fluoroalkyl substances (PFAS), the method comprising:grinding two alkaline hydroxides into a fine powder creating an alkaline mixture, wherein the two alkaline hydroxides are present in a molar ratio equivalent to a melting temperature around a eutectic point of the alkaline mixture;obtaining a PFAS in powder form;mixing the alkaline mixture and the PFAS together; andheating the sample to a reaction temperature that is slightly above the eutectic point of the alkaline mixture, wherein the reaction temperature is less than 300 °C.

22. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 21, wherein the two alkaline hydroxides are any combination of sodium hydroxide, potassium hydroxide, lithium hydroxide, rubidium hydroxide, or cesium hyd roxide.

23. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 22, wherein the two alkaline hydroxides a re sodium hydroxide and potassium hyd roxide.

24. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 23, wherein the sodium hydroxide and potassium hydroxide are present in a molar ratio of 51:49.

25. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claims 23-24, wherein the mixing of the alkaline mixture and the PFAS together includes grinding the alkaline mixture and the PFAS together.

26. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claims 21-25, wherein the reaction temperature is less than 200 °C.

27. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 26, wherein the reaction temperature is around 173 °C.

28. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of any one of the claims 21-27, wherein the alkaline mixture is in molar excess of the PFAS.

29. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 21, wherein a byproduct of said defluorination is fluoride ions.

30. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 21, wherein a recovery of fluoride ions from said defluorination and degradation is up to 100% recovery.

31. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of claim 21, wherein a recovery of fluoride ions from said defluorination and degradation is greater than 60%.

32. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of any one of claims 21-31, wherein a reaction time for said defluorination and degradation is less than 20 hours.

33. The method of defluorination and degradation of per- and poly-fluoroalky I substances (PFAS) of any one of claims 21-32, wherein said PFAS is perfluorooctanesulfonic acid (PFOS), perfluorohexanesulfonic acid (PFHxS), perfluorobutanesulfonic acid (PFBS), polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), perfluorooctanoic acid (PFOA), pefluorononanoicacid (PFNA), or an ammonium salt of hexafluoropropylene oxide dimer acid (GenX™).

34. A method of treating an organofluorine compound in mild conditions, the method comprising:obtaining a mixture of sodium hydroxide and potassium hydroxide at a molar ratio around 51:49 in a powder;mixing the mixture of sodium hydroxide and potassium hydroxide with a powdered form of said organofluorine compound;heatingthe sample to a reaction temperature to between room temperature and 300 °C; andreacting of said organofluorine compound for at least 2 hours.

35. The method of treatingan organofluorine compound in mild conditions of claim 34, wherein the reaction temperature is less than 200 °C.

36. The method of treatingan organofluorine compound in mild conditionsof claims 34- 35, wherein an operating pressure of the reaction is ambient pressure.

37. The method of treatingan organofluorine compound in mild conditionsof claims 34- 36, wherein the reacting of said organofluorine compound is a neat reaction.

38. The method of treatingan organofluorine compound in mild conditionsof claims 34-36, wherein the reacting of said organofluorine compound is free of a liquid solvent.

39. The method of treatingan organofluorine compound in mild conditions of claim 34, wherein the reaction temperature is high enough to maintain the mixture of sodium hydroxide and potassium hydroxide in a molten state.

40. The method of treating organofluorine compounds in mild conditions of any one of claims 34-39, wherein the organofluorine compound comprises a per- and poly-fluoroalkyl substance.

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