WO2020181141A1

WO2020181141A1 - In situ destruction of pfas compounds

Info

Publication number: WO2020181141A1
Application number: PCT/US2020/021272
Authority: WO
Inventors: Thomas Boving; Soni PRADHANANG
Original assignee: University Of Rhode Island Board Of Trustees
Priority date: 2019-03-05
Filing date: 2020-03-05
Publication date: 2020-09-10

Abstract

The invention provides a method of reducing and degrading PFAS pollutants in water by combining plasma light and energy (high-density) with persulfate ions under dynamic conditions.

Description

In Situ Destruction of PFAS Compounds

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims priority to and the benefit of co-pending U. S. provisional patent application Serial No. 62/814,202, filed March 5, 2019, which application is incorporated herein by reference in its entirety.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

[0002] This invention was made with government support under NA/NI18HMFPXXXXG019 awarded by USDA/NIFA. The government has certain rights in the invention.

FIELD OF THE INVENTION

[0003] The invention relates to chemical and pollutant degradation and removal technologies that can be used to treat organic pollutants in water sources. More specifically, the invention relates to decontamination methods that use plasma light to destroy organic, water-contaminating chemicals from the per/polyfluoroalkyl substance (PFAS) family.

BACKGROUND OF THE INVENTION

[0004] Per- and Poly-fluoroalkyl Substances (PFAS) have been manufactured and used extensively in a variety of industries around the globe, including in the United States since the 1940s. Until recently, one of their most important uses was in flame-retardants. Other industrial uses of PFAS included, e.g., as a surfactant, a surface treatment agent, or for coating metals. Of the many PFAS compounds produced, perfluorooctanesulfonic acid (PFOS) and

perfluorooctanoic acid (PFOA) are the most extensively studied. Both compounds are difficult to degrade by natural or anthropogenic means and, therefore, tend to accumulate in the environment and in the human body. Their presence in sources for drinking water is or parucuiar concern uue to persistent presence and demonstrated toxicity to humans and wildlife including various forms of cancer. See, e.g., Post, G. B. et al. Environ. Sci. Eur ., 23(1), 1-52 (2011). The current U.S. Environmental Protection Agency (EPA) health advisory for PFAS in drinking water is 70 ppb (as PFOS and/or PFOA). Across the globe, however, PFAS have been detected at much higher levels in sources for public drinking water suppliers at many locations, and hence pose a worrisome environmental threat.

[0005] Because PFAS contaminants are extremely recalcitrant and resist most degradation methods, the most often used method to remove them from water is by means of activated carbon filtration, which is very expensive. To that end, this invention discloses a novel and more economical process leading to the degradation and destruction of PFAS in polluted bodies of water, e.g., surface water, ground water, industrial, agricultural or residential runoffs, wastewater, brooks, rivers, ponds, lakes, and oceans.

[0006] The present invention makes significant improvements to a water treatment technology that can be characterized as an Advanced Oxidation Process (AOP). See, Glaze, W.H. et al. Ozone: Science & Engineering, 9(4), 335-352 (1987). AOPs utilize primary oxidation reactions to produce hydroxyl and/or sulfate radicals as byproducts leading to further oxidation via secondary reactions. Common AOP technologies include classic and modified Fenton’s reagent (Fe(II) + H2O2), peroxone, and activated persulfate. See, Huling & Pivetz, In-Situ

Chemical Oxidation , U.S. EPA, Office of R&D, National Risk Management Research Laboratory (2006). Sulfate radical based AOPs (i.e., activated persulfate) have been shown to degrade long and short chain PFAS via electron transfer. See Kutsuna & Hori, Int’l J of Chem Kinetics , 39(5), 276-288 (2007).

[0007] Different means exist to activate the oxidation power of persulfate ions, including peroxone (O₃ + H2O2), iron or other catalysts, pH-altering chemicals, the use of microwave or ultraviolet (UV) light, or heat. For example, in U.S. Patent No. 7667087, a method is disclosed for treating contaminated soils and water with a combination of (a) persulfate and ozone; or (b) persulfate, ozone and hydrogen peroxide. However, under this approach, ozone is first generated separately and then mixed with the persulfate solution. The time it takes to produce ozone in a separate device and to transfer and mix it with a second reagent (e.g., persulfate) significantly diminishes the ozone concentration available for PFAS breakdown. According to McClurkin et al. J of Stored Products Research 55, 41-47 (2013), the ozone half-life time is omy aooui JO ro minutes. In large-scale water processing facilities where ozone generation and mixing take anywhere from 15 to 30 minutes or even longer, the fast diminishing in ozone’s oxidative power poses a great challenge to the task of degrading recalcitrant fluorinated chemicals such as PFAS.

[0008] Therefore, there is a strong need for improvement in the existing AOPs to activate and harness the oxidation power of persulfate more effectively or an AOP with a novel approach.

SUMMARY OF THE INVENTION

[0009] The present invention meets this challenge by devising a process that relies on the in situ formation of chemical radicals to interact with PFAS, which eventually leads to the degradation and destruction of PFAS. In this process, chemical radicals with oxidative power are generated on site or in close proximity to the target contaminants such that they interact in a time-sensitive fashion. According to a preferred embodiment of the invention, water and associated surfaces (e.g., soil) that are confirmed or suspected of being polluted with PFAS are dosed with dissolved sodium persulfate solution immediately prior to, simultaneous with, or shortly after (e.g., within 1, 2, 5, 10, 15 minutes) entering a reactor unit that generates

high-intensity plasma light, which emits irradiation including light in the UV spectrum at a high level of energy density. While not wishing to be bound by any particular theory, we believe the ensuing decontamination likely takes place as follows: the plasma light interacts with water to produce ozone in situ ; ozone interacts immediately with water under UV irradiation, and generates radicals such as hydroxyl radials (OH·). Meanwhile, the presence of sodium persulfate in the water leads to the formation of sulfate radicals (SOT·), under photolysis conditions.

Together, these radicals attack the PFAS compound, breaking it up. In comparison to

conventional UV irradiation, the process according to the invention is amplified by an overall greater energy density that can be generated by applying plasma light and the option of using different noble gas mixtures for modulating the electromagnetic energy spectrum of the plasma light. These unique properties set the present invention apart from other, conventional means of electromagnetic irradiation, such as those relying on Mercury lamps to produce UV. Treatment according to principles of the invention results in lower or negligible PFAS concentrations in the water exiting from the unit. [00010] In one aspect, the invention relates to a method of reducing rne eoneenrrauon or

PFAS in a body of polluted or contaminated water, comprising the steps of: (a) adding persulfate ions to the body of water found or suspected to be polluted with at least one chemical member of the PFAS family; and (b) directing the body of water containing persulfate ions to pass adjacent a generator that generates plasma light such that sufficient amounts of persulfate ions are activated in situ and thereby reduce the concentration of the at least one chemical member of the PFAS family in the body of water, preferably by a significant amount, e.g., about 5, 10, 20, 30, 40, 50, 60, 70, 80, 90 per cent or more.

[00011] In one embodiment, the plasma light generator interacts with the water being treated to produce ozone in situ such that the oxidative power of the persulfate is fully harnessed. In various embodiments, the plasma light generator generates high concentrations of extreme UV irradiation, or, irradiation under about 193 nm, or no greater than about 185 nm in wavelength.

[00012] In another aspect, the invention features a dynamic system where the water being treated is made to flow continuous past the plasma light generator, and preferably inside a reactor unit made of a housing that can sustain long-term exposure to strong oxidative and/or reducing agents.

[00013] In an embodiment, the invention provides a decontamination apparatus for reducing the concentration of a PFAS compound in a body of liquid, the device including:

(a) a housing for holding a body of liquid found or suspected to be polluted with at least one chemical member of the PFAS family;

(b) a plasma light generator situated in or near the housing, wherein the plasma light generator, when electrically powered, emits plasma light at high energy density; and

(c) a pump for making the body of liquid flow by the generator to receive plasma light.

[00014] In a feature, the plasma light generator in inventive embodiments can be a Light Emitting Plasma (LEP) lamp, or, generates plasma by exciting noble gas mixtures. In some embodiments, the plasma light generator utilizes radio frequency energy.

[00015] The foregoing and other objects, aspects, features, and advantages of the invention will become more apparent from the following description and from the claims. BRIEF DESCRIPTION OF THE DRAWINGS

[00016] The objects and features of the invention can be better understood with reference to the drawings described below, and the claims. The drawings are not necessarily to scale, emphasis instead generally being placed upon illustrating the principles of the invention. In the drawings, like numerals are used to indicate like parts throughout the various views.

[00017] FIG. 1 schematically illustrates exemplary embodiments of a method to reduce the concentration of a pollutant in water according to the invention.

[00018] FIG. 2A (PFOS) and FIG. 2B (PFOA) illustrate the chemical formula for two members of the PFAS family.

[00019] FIG. 3 illustrates exemplary embodiment of a plasma light generator useful in practicing the present invention.

[00020] FIG. 4 illustrates another exemplary embodiment where a plasma light generator is employed in practicing the present invention.

DETAILED DESCRIPTION OF THE INVENTION

I. DEFINITION

[00021] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as is commonly understood by one of ordinary skill in the art to which this invention belongs.

[00022] As used in the specification and claims, the singular form“a”,“an”, or“the” includes plural references unless the context clearly dictates otherwise. For example, the term“a unit” includes a plurality of units including mixtures of different kinds thereof. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as support for the recitation in the claims of such exclusive terminology as “solely,”“only” and the like in connection with the recitation of claim elements, or use of a “negative” limitations, such as“wherein [a particular feature or element] is absent,” or“except for [a particular feature or element],” or“wherein [a particular feature or element] is not present (included, etc.)...”.

[00023] When a dimensional measurement is given for a part herein, the value is, unless explicitly stated or clear from the context, meant to describe an average for a necessary portion of the part, i.e., an average for the portion of the part that is needed for the srareu purpose iy accessory or excessive portion is not meant to be included in the calculation of the value.

[00024] As used herein, the recitation of a numerical range for a variable is intended to convey that the invention may be practiced with the variable equal to any of the values within that range. Thus, for a variable which is inherently discrete, the variable can be equal to any integer value within the numerical range, including the end-points of the range. Similarly, for a variable which is inherently continuous, the variable can be equal to any real value within the numerical range, including the end-points of the range. As an example, and without limitation, a variable which is described as having values between 0 and 2 can take the values 0, 1 or 2 if the variable is inherently discrete, and can take the values 0.0, 0.1, 0.01, 0.001, or any other real values >0 and <2 if the variable is inherently continuous.

[00025] As used herein,“about” means within plus or minus 10%. For example,“about 1” means“0.9 to 1.1”,“about 2%” means“1.8% to 2.2%”,“about 2% to 3%” means“1.8% to 3.3%”, and“about 3% to about 4%” means“2.7% to 4.4%”

[00026] As used herein, the term“persulfate” refers to both monopersulfate and

dipersulfate, and is typically in the form of an aqueous solution. Examples include sodium, potassium or ammonium dipersulfate, sodium or potassium monopersulfate, or a mixture thereof.

[00027] As used herein, the term“ in situ” refers to an on site (action) or the characteristic of close proximity that allows interaction within a relatively short period of time, preferably, under a minute and even instantaneously. Such periods of time may differ under varying settings depending on factors such as temperature, viscosity, pressure, and the existence or absence of a physical barrier or enclosure that affect how elements at concern intermingle and disperse.

[00028] As used herein, the term“plasma light” refers to light and energy generated by exciting one or more gases to an ionized or partly ionized state, and can include full spectrum light spanning from infrared, visible light and/or ultraviolet radiation, often with higher outputs of electromagnetic energy per reference area/volume than conventional UV irradiation.

[00029] The present invention provides a more effective method than conventional methods for degrading and eliminating a stubborn water pollutant that is harmful to human health and wildlife at large. In one aspect, the present invention adds plasma light to the arsenal of an environmental engineer who wants to degrade and reduce PFAS contamination in water.

Exposure to plasma light in situ generates ozone and a set of chemical radicals in the very body of water being treated. In another aspect, the polluted water is also dosed wirn persuuare ions, suen that when ozone is generated in situ, it is done in the presence of persulfate ions. As a result, reaction time between fresh ozone and persulfate ions is maximized to produce more radicals. These radicals serve as strong oxidants that tear apart bonds in PFAS compounds, breaking them into fluoride, water and carbon dioxide, rendering the water under treatment clean or less polluted.

[00030] Referring now to FIG. 1, in a schematic representation, an embodiment of the present invention can be summarized as including the following steps: to a body of water that has been polluted by at least one member of the PFAS chemical family, persulfate is added. The water being treated is pumped or otherwise caused to flow past, preferably continuously, a source of plasma light irradiation, e.g., by being continuously pumped through a treatment or reactor unit that contains one or more of such irradiation source 10. After sufficient treatment, which may require multiple rounds of cycling through the same reactor unit(s) or serially passing through multiple, different reactor units, or a combination of the above, treated water exits the facility with significantly lower level of the PFAS chemical, preferably below levels set by relevant health and environmental regulation and certifiably safe for consumption. The broken down products of PFAS may include fluoride ions (F ) or hydrogen fluoride (HF), water, CO₂, and sulfate ions (SO₄ ² )

[00031] Common examples of PFAS pollutants found in water and soil include PFOS and PFOA (FIGS. 2A and 2B). Methods of the present invention are designed to break down the F-C chains in PFAS compounds through an oxidative and/or reductive process, with end products that are less harmful or harmless. Persulfate is used as part of the oxidant solution to degrade PFAS because of, among other things, strong oxidative power and relatively long half-life. It may be introduced to water or its surroundings as a liquid reagent, e.g., in the form of an aqueous solution of sodium persulfate or other salts that contains persulfate ions. The amount or concentration of resulting persulfate concentration in the water being treated is within the knowledge of one skilled in the art. As a guideline, in general, the persulfate dosage should be adjusted based on the initial PFAS concentration, throughput, and the ultimate use for the treated water. In a method embodiment of the invention, a higher initial PFAS concentration (pre-treatment) may require a higher persulfate concentration, while treating a potential drinking water source will require that the persulfate dosages not to exceed the sulfate (SO₄ ² ) maximum contaminant levels (MCL) set by the U.S. EPA. If treatment time is not a concern, slower flow rates can maKe up ior lower persulfate concentrations. Overall, one skilled in the art can adjust these and other values to optimize PFAS treatment.

[00032] However, the oxidative power from persulfate needs to be activated in order to break up an organic compound. The polluted water 15 is fed through a treatment facility that includes one or more plasma light generators 10 housed inside one or more reactor units 20 so that energy from the plasma irradiation can be used to activate persulfate and generate oxidative radicals to attack the contaminants (FIG. 4). In an embodiment, the reactor unit(s) includes one or more pumps 18 to process water at a flow rate of 5 gpm or more, preferably at least 10 gpm, and even more preferably at least 20, or 25 gpm. In an exemplary embodiment, each reactor unit has a housing 25 made of one or more materials that can sustain extended periods of exposure to strong oxidizers, e.g., durable polymers such as high-density polyethylene (HDPE). Alternatively, the housing 25 can be fabricated of glass.

[00033] Any suitable plasma light (PL) generator can be used for practicing the present invention. Referring to FIGS. 3 and 4, an exemplary PL generator 10 uses radio frequency energy driven by a solid-state power amplifier to ionize gases (e.g., noble gases) inside an electrodeless quartz bulb. In a preferred, smaller embodiment that is intended for household use, a

commercially available PL generator runs on household-strength electricity (e.g., 110 V in the U.S.), with a maximum energy output of about 1.5 KW or 2.0 KW. A particular example of such a PL generator is a commercially available Light Emitting Plasma (LEP) lamp (FIG. 4) which is based on using radiofrequency and a ceramic resonator to stimulate a quartz lamp. The liquid flow speed when this embodiment is processing water can be, e.g., about 1 L/min.

[00034] In embodiments of the invention, the PL generator may produce full spectrum light from infrared to ultraviolet, and we have found it much more powerful and effective than using UV light alone in activating persulfate. The typical wavelength of UV used in conventional methods for activating persulfate is around 254 nm, which has shown limited success in degrading PFAS and other fluorinated organic compounds. According to studies in Lutze H. V. et al, Water Research 129:509-519 (2018), the energy demand required for generating SO4 radicals by photolysis of S2O8² (UV/ S2O8² ) is“very high”: a 90% degradation of a perfluorinated carboxylic acid (PFCA) by UV/ S2O8² was estimated to be 55 kW h m^-3 in pure water. [00035] In contrast, plasma-generated UV radiation used in the present invention uiners from conventional UV, as reactive species are present in high concentrations with higher energy density in the former. For example, at the same energy input, say 100 Watts, plasma light generates a higher energy output compared to conventional UV light, as shown by studies of LEP lamps where these lamps are found to achieve efficacies above 90 lumens per watt. In particular, extreme ultraviolet radiation (EUV or XUV), electromagnetic radiation with wavelength < about 193 nm in the spectrum, can only be created from plasma. Extreme ultraviolet radiation can be generated by the sun corona naturally, or, as in the present invention, via a PL generator.

[00036] While not wishing to be bound by any particular theory, our experiments have lead to belief in the following working theory involving multiple oxidative radicals attacking PFAS chemicals. In chemistry, a radical is an atom, molecule, or ion that has an unpaired valence electron. The proposed reaction pathway that leads to the destruction of PFAS is initiated by exposure of polluted water to a high intensity Plasma light, which produces ozone when operating at a wavelength of about 185 nm (UV spectrum). The light source could be a commercially available Microwave Plasma UV Lamp (MPUVL) or Light Emitting Plasma (LEP) lamp as illustrated in FIG. 4. The ozone (O3) molecules react with water to form hydroxyl radials (OH·):

3O3 + 3H₂0 2 OH· + 40₂ + 2H₂0

[00037] A second OH· generation pathway relies on the UV light exciting the water molecule at about 100-280 nm range:

H₂0— > OH· + H

In addition to the hydroxyl radials (OH·) produced here, the hydride ion (H ) is a strong reducing agent and may also play a role in the PFAS degradation.

[00038] Furthermore, we have evidence that the sulfate radical (SO4 ·) is also involved in the PFAS degradation as follows: First, it forms from persulfate ions (S₂0x^2-) via photolysis according to prior research (Dogliotti and Hyon, J of Physical Chem , 71(8), 2511- 2516, 1967):

S₂0₈ ² — > 2 S0₄ ·

[00039] Once produced, SO4 · interacts with water to produce additional OH·:

S0₄ · + H₂0 HSO4 + OH· [00040] The sulfate radical exhibits a nonselective oxidation pattern anu can quicKiy decompose most organic pollutants in water. Sulfate radicals will transform to non-toxic sulfate subsequent to the oxidation reaction, eliminating the need for special disposal considerations.

[00041] Besides the production of OH· by SO4 ·, our work further suggests that sulfate radical forms when persulfate is combined with ozone (see Cashman, M. el al.“Identification of hydroxyl and sulfate free radicals involved the reaction of 1,4-dioxane with peroxone activated persulfate oxidant,” J Haz. Mat. 380: 120875 (2019).

[00042] While the PFAS destruction pathway is not fully understood yet, our work suggests that it likely involves a step-wise defluorination. The overall reaction can be

approximated by:

PFAS + S0₄ · + OH· F + H2O + HSO4 + C0₂

[00043] In Liang et al. Remediation, 28: 127-134 (2018), data is presented on PFAS defluorination rates when oxidizing with electrochemical oxidation. The group reported rapid degradation where half time is about an hour. Also, defluorination was quantitative. See also, Yang et al., PLOS ONE, 8: 10, e74877 (2013); Trojanowicz et al., Chem Engineering J,

336: 170-199, (2018).

[00044] Our data confirms that defluorination by peroxone activated persulfate was rapid and resulted in stoichiometric defluorination (data not published). In a preferred embodiment, full defluorination of PFAS is achieved within minutes.

[00045] Besides the stated advantage of an aggressive treatment process where reactive species such as ozone is directly generated in the polluted water in situ, the present invention is also advantageous in that treatment according to embodiments of the invention results in complete defluorination, and only non-toxic by-products will be created, including fluoride, carbon dioxide and sulfate species.

[00046] The present invention can also be used in combination with other methods for degrading organic pollutants, especially other AOPs, are included in various embodiments. For example, other reagents that can be added to the system of the invention include, but are not limited to: Fenton’s regent, iron powder, and hydrogen peroxide. In order to confirm the presence of pollutants in the water, embodiments of the water treatment methods according to the present invention may include steps for testing to detect the presence of the at least one chemical member of the PFAS family, before, during and/or after the treatment. Such testing is wen wumn me knowledge of one skilled in the art and is not further described here.

[00047] EXAMPLE

[00048] [Use of Inventive Method to Mineralize Six PFAS Compounds]:

[00049] Experiments were carried out using a method embodiment of the present invention to test if plasma light/energy can mineralize six of the EPA-listed PFAS compounds with or without sodium persulfate.

[00050] Stock solutions (1 Liter) of five PFAS compounds listed by the EPA under the Unregulated Contaminant Monitoring Rule (UCMR) were prepared in Milli-Pure water. The five PFAS compounds were: Perfluoroheptanoic Acid (PFHpA), PFOA, Perfluorononanoic Acid (PFNA), PFOS, and Perfluorohexanesulfonic Acid (PFHxS). An additional, non-UCMR listed PFAS compound (Perfluorodecanoic Acid; PFDA) was included to test the degradation of longer-chained, higher molecular weight PFAS. These solutions were then shipped to a certified third-party laboratory for testing. Table 1 summarizes the respective PFAS concentrations in the stock solutions.

[00051]

[00052] Table 1: Aqueous phase stock solutions (1 Liter) of UCMR-6 PFAS compounds

[00053] A second, persulfate solution (~50 ml) containing 6.19 g Sodium Persulfate (available from Klozur) was prepared in Milli-Pure water. As noted below, a volume of 1 ml of the Sodium Persulfate solution is added to 100 ml of PFAS stock solution immediately prior to the plasma experiment. [00054] For each of the six PFAS compounds, four samples are tested under plasma irradiation as follows:

[00055] (a) Aqueous blank solution containing no PFAS spike (Milli-Pure water)-negative control;

[00056] (b) PFAS stock solution with no persulfate added;

[00057] (c) PFAS stock solution: 1 ml of sodium persulfate solution added per 100 ml of

PFAS stock solution (immediately prior to irradiation, e.g., within 30 seconds or a minute); and [00058] (d) Diluted persulfate solution: 1 ml sodium persulfate solution added per 100 ml

Milli-Pure water.

[00059] Each of these solutions is plasma-irradiated using an LEP lamp for three durations, i.e., 1 minute, 10 minutes and 60 minutes, all in 125 ml sample volume.

[00060] Sampling Matrix: A total of 12 samples, each 125 ml of sample volume, are generated (see Table 2), including a duplicate of the PFAS stock solution (before irradiation) and a duplicate of PFAS stock solution with persulfate added after 60 min of plasma exposure.

[00061]

[00062] Table 2: Number of samples generated per matrix solution.

[00063] Sampling is conducted using PFAS-free, high-density polyethylene (HDPE) 125-ml containers with unlined caps made of HDPE or polypropylene. Care is taken not to use polytetrafluoroethylene products (tubing, sample containers, and sampling tools). Glass is used in conducting plasma-reactor testing. Care is taken to decontaminate the reactor vessel after each experiment to avoid cross-contamination. [00064] Analytics: The analysis of PFAS liquid samples is conducted by a commercial laboratory that is NELAP accredited for the DoD QSM compliant method and that analyzes PFAS by LCMSMS Compliant protocol with QSM 5.1 Table B-15.

[00065] After the six PFAS compounds (PFDA, PFHpA, PFhxS, PFOA, PFOS, PFNA) are analyzed, methods of the invention are used to reduce or eliminate additional PFAS compounds found in solution form. The PFAS compounds covered in the extended lab protocol largely overlap with the EPA’s Method Development Analyte List (see ERDP ESTCP QA QC

Guidelines Final November 2018).

[00066] Results: During treatment using plasma light, the aqueous solutions respectively containing the six PFAS compounds become cloudy and change color, providing visual indication that reactions are taking place. Following the intended durations of treatment time, samples are individually tested via a liquid chromatography/tandem mass spectrometry

(LC-MS/MS) method that is compliant with the DoD/DoE Quality Systems Manual (QSM) for Environmental Laboratories QSM 5.1, for amounts of PFAS compounds that remain. The analytical results indicate significant reduction in the levels of the PFAS compounds tested.

[00067] While the present invention has been particularly shown and described with reference to the structure and methods disclosed herein and as illustrated in the drawings, it is not confined to the details set forth and this invention is intended to cover any modifications and changes as may come within the scope and spirit of the following claims. All publications and patent literature described herein are incorporated by reference in entirety to the extent permitted by applicable laws and regulations.

Claims

What is claimed is:

1. A method of reducing the concentration of a per- or poly-fluoroalkyl substance (PFAS) in a body of water, the method comprising the steps of:

(a) adding persulfate ions to the body of water found or suspected to be polluted with at least one chemical member of the PFAS family; and

(b) directing the body of water containing persulfate ions to pass adjacent a generator that generates plasma light such that sufficient amounts of persulfate ions are activated in situ and thereby reducing the concentration of the at least one chemical member of the PFAS family in the body of water.

2. The method of Claim 1, wherein step (a) comprises adding sodium persulfate solution to the body of polluted water.

3. The method of Claim 1, wherein the plasma light generator is housed in a reactor unit.

4. The method of Claim 3, wherein the reactor unit is made of high-density polyethylene

(HDPE) or glass.

5. The method of Claim 1, wherein the plasma light generator comprises a Light Emitting

Plasma (LEP) lamp.

6. The method of Claim 1, wherein the plasma light generator generates plasma by exciting noble gas mixtures.

7. The method of Claim 1, wherein the plasma light generator generates extreme ultraviolet light.

8. The method of Claim 1, wherein the plasma light generator generates irradiation with a

wavelength under about 193 nm.

9. The method of Claim 1, wherein the plasma light generator generates irradiation with a

wavelength around or under 185 nm.

10. The method of Claim 1, wherein the plasma light generator uses radio frequency energy.

11. The method of Claim 1, wherein, in step (b), the plasma light interacts with the water to

produce ozone in situ.

12. The method of Claim 1, wherein step (b) further comprises causing the body of water to flow continuously past the plasma light generator.

13. The method of Claim 1, wherein the body of polluted water is selected from the group consisting of surface water, ground water, industrial, agricultural or residential runoffs, wastewater, brooks, rivers, ponds, lakes, and oceans.

14. The method of Claim 1, further comprising adding hydrogen peroxide to the body of polluted water.

15. The method of Claim 1, further comprising adding Fenton’s regent or iron powder to the body of polluted water.

16. The method of Claim 1, further comprising testing to detect the presence of the at least one chemical member of the PFAS family to confirm success of treatment.

17. A decontamination apparatus for reducing the concentration of a per- or poly-fluoroalkyl substance (PFAS) in a body of liquid, the device comprising:

18. The decontamination apparatus of Claim 17, wherein the housing is made of high-density polyethylene (HDPE) or glass.

19. The decontamination apparatus of Claim 17, wherein the plasma light generator comprises a Light Emitting Plasma (LEP) lamp.

20. The decontamination apparatus of Claim 17, wherein plasma light generator generates plasma by exciting noble gas mixtures.

21. The decontamination apparatus of Claim 17, wherein the plasma light generator generates extreme ultraviolet light.

22. The decontamination apparatus of Claim 17, wherein the plasma light generator generates irradiation with a wavelength under about 193 nm.

23. The decontamination apparatus of Claim 17, wherein the plasma light generator generates irradiation with a wavelength around or under 185 nm.

24. The decontamination apparatus of Claim 17, wherein the plasma light generator uses radio frequency energy.