UV Water Purification System and Method

Abstract

The present invention provides a method for removing contaminants from an aqueous solution using ultraviolet light having a wavelength of 230 nm or less under reducing conditions.

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority of U.S. Provisional Application No. 63 / 345,784, filed May 25, 2022. The entire content of the above - mentioned application related to this application is hereby incorporated by reference herein.

[0002] Statement Regarding Federally Sponsored Research This invention was made with government support under Grant No. 2131745 awarded by the National Science Foundation. The government has certain rights in this invention.

Background Art

[0003] Perfluoroalkyl and polyfluoroalkyl compounds (PFAS) have been widely detected in terrestrial, aquatic, and atmospheric environments due to their wide range of applications, such as manufacturing, firefighting activities, food packaging, and household products, as well as improper disposal. Long-term exposure to PFAS-contaminated environments has led to the widespread detection of PFAS in human serum, posing a major threat to public health. The US EPA has issued lifetime health advisories of 0.004 parts per trillion (ppt) for perfluorooctanoic acid (PFOA) and 0.02 ppt for perfluorooctane sulfonic acid (PFOS) in drinking water, and national drinking water standards for PFOA and PFOS are expected to be issued soon. The EPA has proposed designating PFOA and PFOS as hazardous substances under the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA). State agencies have proposed various regulatory and notification levels for PFAS compounds in drinking water. For example, in New Jersey, the maximum contaminant levels (MCLs) for PFOS and perfluorononanoic acid (PFNA) are set at 13 ppt, and the MCL for PFOA is 14 ppt. Massachusetts has established an MCL of 20 ppt for the sum of six PFAS compounds, including PFOA, PFOS, perfluorohexane sulfonic acid (PFHxS), PFNA, perfluoroheptanoic acid (PFHpA), and perfluorodecanoic acid (PFDA). The newly established US EPA Unregulated Contaminant Monitoring Rule, 5th Edition (UCMR5) requires the monitoring of 29 PFAS compounds in public drinking water systems.

[0004] Regulatory measures adopted for PFAS at the federal and state levels strongly promote the development of technologies for PFAS treatment in different environmental settings. Commonly used physical treatment technologies such as activated carbon adsorption, ion exchange, and membrane separation (i.e., nanofiltration and reverse osmosis) separate PFAS from raw water into a solid or liquid medium based on phase separation. Therefore, secondary waste streams concentrated in PFAS are generated, and destructive treatment is required before discharge. So far, there is a lack of efficient and sustainable technologies for completely destroying PFAS. Conventional destruction technologies using chemical reagents and microorganisms are not effective in decomposing PFAS because of their limited ability to break the C-F bonds of fluoroalkyl chains. High-temperature incineration can destroy PFAS compounds but suffers from intensive energy consumption and high operating costs.

[0005] Reductive treatment using highly reducing species is one of the most effective approaches for cleaving C-F bonds and destroying PFAS compounds. Hydrated electrons (i.e.,

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[0006] Vacuum ultraviolet light (VUV)-driven photolysis of water provides a promising photochemical platform for the treatment of PFAS. Compared to conventional UV light in the 245 - 400 nm range, VUV light specifically refers to the wavelength range of 100 - 200 nm. Far-UVC light specifically refers to the wavelength range of 200 - 220 nm. High-energy UV photons (λ ≤ 220 nm) are strongly absorbed by water molecules, photolyzing water to a mixture of both oxidative and reductive reactive species including hydroxyl radicals (HO·), hydrogen atoms (H·), and

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[0007] Currently, there is a need for improved methods for removing contaminants from water (e.g., drinking water, industrial waste, hazardous waste). In particular, methods that can be effectively and economically implemented on a commercial scale are needed. More effective and energy-efficient methods are needed.

Summary of the Invention

[0008] To overcome the drawbacks of conventional UV photochemical systems, an adjustment strategy for the UV water photolysis system has been developed that minimizes the scavenging effect and converts unwanted reactive species into hydrated electrons, increasing the yield of hydrated electrons and enhancing the reducing polarity. It has been found that the formation and abundance of reactive radical species can be chemically regulated by environmentally sustainable solutes, creating a highly polarized reducing environment that can significantly promote the degradation of contaminants (e.g., defluorination of PFAS compounds). Specifically, environmentally sustainable adjustable chemicals (e.g., N 2 , H 2, alcohol or carboxylic acid) can stabilize hydrated electrons or convert HO· to highly reduced species (e.g., H· and

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[0009] To selectively generate hydrated electrons from water to destroy pollutants (e.g., PFAS) and avoid generating secondary by-products that require further treatment, an adjustable, sustainable, and highly effective UV photochemical system has been developed. Hydrogen gas (H 2 ) was selected as an adjustable chemical for the UV photochemical system considering its ability to convert HO· to

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[0010] PFOA and PFOS were selected as model PFAS compounds. PFOA and PFOS are the first two PFASs expected to be regulated by the US EPA. These are two of the most stable PFAS compounds and are common end products due to the degradation of other PFAS precursor compounds. The effects of H 2 and water chemical parameters (e.g., solution pH and coexisting components) on the degradation and defluorination of PFOA and PFOS were investigated. LC-HRMS / MS was used to monitor the degradation products of PFOA and PFOS.

[0011] Thus, in one embodiment, the present invention provides a method comprising treating an aqueous solution containing contaminants with ultraviolet light having a wavelength of 220 nm or less under reducing conditions to remove at least 75% of the contaminants from the solution.

[0012] In another embodiment, the present invention provides an aqueous solution containing contaminants, adjusts the aqueous solution by adding an adjustable chemical, optionally adjusts the pH of the adjusted solution to be about 7 to about 12, and irradiates the adjusted solution with UV light having a wavelength of about 100 nm to about 230 nm until at least 75% of the contaminants are removed from the solution.

[0013] In another embodiment, the present invention provides an aqueous solution containing contaminants, sprays H 2 gas into the aqueous solution to provide a sprayed solution, optionally adjusts the pH of the sprayed solution to be about 7 to about 12, and irradiates the sprayed solution with UV light having a wavelength of about 100 nm to about 230 nm until at least 75% of the contaminants are removed from the solution.

[0014] In another embodiment, the present invention Providing an aqueous solution containing contaminants, Adjusting the aqueous solution by adding adjustable chemicals, Optionally, adjusting the pH of the adjusted solution to be about 7 to about 12, Irradiating the adjusted solution with UV light having a wavelength of about 100 nm to about 220 nm until at least 75% of the contaminants are removed from the solution, and providing a method.

[0015] In another embodiment, the present invention is, Providing an aqueous solution containing contaminants, Spraying H 2 Gas into the aqueous solution to provide a sprayed solution, Optionally, adjusting the pH of the sprayed solution to be about 7 to about 12, Irradiating the sprayed solution with UV light having a wavelength of about 100 nm to about 220 nm until at least 75% of the contaminants are removed from the solution, and providing a method.

[0016] In another embodiment, the present invention provides a method comprising irradiating an aqueous solution containing contaminants with vacuum ultraviolet rays and bubbling a gas into the aqueous solution.

[0017] In another embodiment, the present invention provides an apparatus comprising a container for holding an aqueous solution containing contaminants, a high vacuum ultraviolet transmissive quartz sleeve housing and electromagnetic radiation, and a mechanical device component for introducing adjustable chemicals into the container.

Brief Description of the Drawings

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Mode for Carrying Out the Invention

[0019] As used herein, the term "contaminant" includes organic contaminants, metals, metalloids, oxyanions, fluorinated compounds, radionuclides, and microbial contaminants. Non-limiting examples of organic contaminants include chlorinated compounds (e.g., trichloroethylene), 1,4-dioxane, pesticides, and nitroaromatic compounds. Non-limiting examples of metals include hexavalent chromium and pentavalent vanadium. Non-limiting examples of metalloids include selenium and arsenic. Non-limiting examples of fluorinated compounds include fluoroalkyls and perfluoroalkyls (e.g., perfluoroalkyl carboxylates, perfluoroalkyl sulfonates, and fluorotelomers). Non-limiting examples of oxyanion compounds include nitrates, bromates, perchlorates, and chlorates. Non-limiting examples of radionuclide compounds include compounds containing uranium. Non-limiting examples of microbial contaminants include bacteria and viruses.

[0020] When the solution has a pH of from about 7 to about 12, the pH can be at least about 7, at least about 8, at least about 9, at least about 10, or at least about 11. In one embodiment, when the solution has a pH of from about 7 to about 12, the pH is at least about 9.

[0021] When the solution has a pH of from about 2 to about 7, the pH can be less than about 6, less than about 5, less than about 4, or less than about 3. In one embodiment, when the solution has a pH of from about 7 to about 12, the pH is at least about 9.

[0022] The term "aqueous solution" includes solutions containing water. In one embodiment, the aqueous solution contains at least about 25 weight percent water. In one embodiment, the aqueous solution contains at least about 50 weight percent water. In one embodiment, the aqueous solution contains at least about 75 weight percent water. In one embodiment, the aqueous solution contains at least about 90 weight percent water. In one embodiment, the aqueous solution is water. Aqueous solutions include, but are not limited to, municipal wastewater, drinking water, industrial wastewater, rainwater, landfill leachate, concentrated brine wastewater, and the like.

[0023] In one embodiment, at least 85% of the contaminants are removed from the aqueous solution. In one embodiment, at least 90% of the contaminants are removed from the aqueous solution. In one embodiment, at least 95% of the contaminants are removed from the aqueous solution.

[0024] As used herein, the term "removed from the aqueous solution" includes the destruction of the contaminants and / or the conversion of the contaminants into one or more entities that are less toxic than the contaminants.

[0025] As used herein, the term "adjustable chemical" includes any substance that can increase the yield of hydrated electrons and / or minimize the scavenging effect. Electron-donating solutes selectively convert electrons to species that highly reduce electron-deficient oxidative reactive species (e.g., hydroxyl radicals), such as hydrated electrons, and eliminate the scavenging effect of common water components (e.g., dissolved oxygen), thereby increasing the reducing polarity of the reaction system for the reduction treatment of environmental contaminants. In one embodiment, the adjustable chemical is selected from the group consisting of gases, alcohols, and carboxylates. In one embodiment, the electron-donating substance is N 2 gas, H 2 gas, ethanol, isopropanol, and carboxylic acid. In one embodiment, the adjustable chemical is an environmentally sustainable adjustable chemical.

[0026] As used herein, the term "reducing conditions" includes a reaction environment containing hydrated electrons, hydrogen atoms, and / or carbon-centered radicals (e.g., ·CO 2 - ). In one embodiment, the reducing conditions include hydrated electrons. In one embodiment, the reducing conditions are species that highly reduce HO· (e.g., H· and

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[0027] In one embodiment, the wavelength of the light is from about 100 nm to about 230 nm.

[0028] In one embodiment, the wavelength of the light is from about 100 nm to about 220 nm.

[0029] In one embodiment, the wavelength of the light is from about 100 nm to about 200 nm.

[0030] As used herein, the term "drinking water" includes groundwater, surface water, reclaimed water, and rainwater that can be used for human consumption.

[0031] As used herein, the term "industrial waste" includes wastewater discharged from various manufacturing industries and brine wastewater generated from various industrial processes (e.g., ion exchange regeneration brine, reverse osmosis concentrate, and oil and gas produced water).

[0032] As used herein, the term "hazardous waste" includes water-soluble waste containing substances at harmful levels that are regulated or will be regulated in the near future (e.g., organic pollutants, toxic heavy metals, metalloids, radionuclides).

[0033] Here, the present invention is illustrated by the following non-limiting examples.

Example

[0034] Example 1. Photochemical experiment The photochemical decomposition and defluorination of PFOA and PFOS were carried out in a cylindrical borosilicate glass reactor (Ace Glass, 7841 - 05) using a cooling jacket to maintain the temperature of the reaction solution. Three VUV lamps (14W, GPH287T5VH / 4) and one VUV lamp (10W, GPH212T5VH / 4) were packed together to function as a light source. The light source emitted a combination of 185 nm and 254 nm. The irradiance of VUV light at 185 nm was 8% compared to the irradiance of UVC light at 254 nm, which was the active VUV wavelength investigated in this study. The lamps were housed in synthetic quartz sleeves (Suprasil 310, Heraeus) with high UV and VUV transmittance and were immersed in 500 mL of the reaction solution. 2 To minimize the attenuation of VUV light by O 2 high - purity N 2 gas was purged from the air inside the quartz sleeves and flowed continuously through the quartz sleeves during the reaction. The heat generated from the lamps was absorbed by the reaction solution cooled by tap water passing through the cooling jacket.

[0035] Typically, a 500 mL solution containing 25 μM of the PFAS compound was sparged with H 2 for 30 minutes before irradiation. The pH of the solution was adjusted to a target level between 7 and 12. H 2 gas was continuously bubbled through the solution during the reaction process. Buffer solutions were not used to maintain the solution pH because they could potentially trap reactive species in the VUV photochemical system. At predetermined times, 6 mL of the reaction solution was removed from the reactor and transferred to a glass vial. To confirm the role of reactive species in the VUV photochemical system, control experiments were carried out by sparging the solution with N 2 , air, or other selected gases containing N 2 O. Using a low initial concentration of 2.5 μM for PFOA, H 2The effect of pH on an adjusted VUV photochemical system was studied. This level of PFOA functions as the upper limit of highly contaminated groundwater near PFAS industrial discharge sites or some military sites that frequently conduct firefighting activities, and also functions as a typical level of PFAS in industrial wastewater. To investigate the effect of coexisting components, 5 mM of chloride, 5 mM of sulfate, 5 mM of carbonate, or 5.4 mg-C / L of Suwannee River fulvic acid was added to a 25 μM PFOA solution saturated with H 2 at pH 12.0. To evaluate the applicability of a VUV system with H 2 permeation of PFAS-affected drinking water, trace amounts of 1300 ng / L of PFOA or 580 ng / L of PFOS were added to Riverside CA tap water, and the destruction of PFAS during VUV treatment was evaluated.

[0036] Sample analysis The concentration of fluoride ions was measured by an ion-selective electrode (ISE, Fisherbrand accumet solid-state) connected to a Thermo Scientific Orion Versa Star meter. Total ion strength adjustment (TISAB) buffer was added to an equal volume of the sample solution to mask the slight difference in ionic strength between samples and buffer to a final pH value of 5 - 5.5. For sample solutions with a pH of 12.0 or higher, the TISAB buffer did not have sufficient buffering capacity to adjust the pH value of the sample solution to the expected range. To remove interference from hydroxide ions, a small amount of 1 M hydrochloric acid was added to neutralize the sample solution. F - The accuracy of the fluoride ISE for measurement was verified by ion chromatography. The percentage of defluorination (DeF%) was calculated by Equation 1.

Equation

[0037] Results and Discussion The cleavage of the C-F bond in the PFAS alkyl chain is an important indicator for evaluating the effectiveness of destructive technologies for PFAS treatment. The defluorination of PFOA was investigated in a gas-saturated alkaline solution under irradiation with VUV (λ = 185 nm) and conventional UV light (λ = 254 nm) (Figure 1). Under irradiation with conventional UV light at 254 nm, negligible defluorination (less than 4%) was observed. Similarly, when the VUV system was not adjusted with chemical additives, negligible defluorination (less than 20%) was observed under irradiation with VUV light at 185 nm, indicating that the conventional VUV system was not effective for PFAS destruction. In contrast, when the VUV system was adjusted with hydrogen gas, the defluorination percentage increased significantly from 23% to 92% in 180 minutes. The VUV system adjusted with nitrogen gas (N 2 ) also enhanced the defluorination of PFOA, but to a lesser extent (i.e., the defluorination rate increased from 23% to 77%). Adding nitrous oxide gas (N 2 O) as a candidate for the adjustment chemical to the VUV system was not effective.

[0038] The influence of the sparging gas on the defluorination of PFOA was due to their chemical conditioning effect on the speciation and abundance of reactive species in the aqueous phase. At pH 12, VUV photons photolyzed mainly water molecules and hydroxide anions into HO· and

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[0039] In previous studies,

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[0040] Such a strong scavenging effect was observed for

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[0041] The adjustment effect of H on the formation and abundance of reactive species in the aqueous phase 2 was

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[0042] In defluorination

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[0043] H 2 When replaced with N 2 O, the defluorination rate decreases from 92% to 19%, which indicates that

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[0044] The actual water matrix also contains other inorganic and organic components that can affect the radical chemistry in the VUV photochemical system and thus its performance for PFAS treatment. H 2 The effects of common water components on the defluorination of PFOA in a tuned VUV photochemical system were investigated. When the coexisting components were at levels relevant to the groundwater matrix, H 2 the saturated VUV photochemical system exhibited PFOA defluorination efficiency equal to or higher than that in the absence of coexisting components (Figure 2). Specifically, the presence of chloride and sulfate anions promoted defluorination by 4 - 6%, which resulted in nearly 100% defluorination after 180 minutes of reaction. Humic acid had no effect on defluorination. Carbonate reduced the defluorination rate more significantly, but ultimately more than 80% defluorination was achieved.

[0045] The effects of anions and dissolved organic matter on the defluorination of PFOA were due to H 2 their effects on the speciation and abundance of reactive species in the saturated VUV photochemical system. Chloride and sulfate anions can strongly absorb VUV light

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[0046] PFAS - contaminated water can be nearly neutral (e.g., groundwater) or highly alkaline (e.g., ion - exchange regeneration brine). H 2The effect of pH on the defluorination and mineralization of PFOA in an adjusted VUV photochemical system was investigated. The results showed that the solution pH affected the reactivity of the system and that alkaline conditions were favorable for PFAS destruction (Figure 3). Specifically, when the pH exceeded 9, more than 80% defluorination was achieved within 60 minutes. The defluorination percentage decreased to 60% at pH 9 and 40% at pH 7. The mineralization of PFOA decelerated below pH 10, but more than 85% of PFOA was removed within 40 minutes regardless of the solution pH. pH mainly affected the

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[0047] H 2The performance of the tuned VUV photochemical system was evaluated for the abatement of trace levels of PFAS in drinking water. PFAS-impacted drinking water was simulated by spiking typical water constituents (e.g., chloride, sulfate, bicarbonate, and nitrate) having concentrations five orders of magnitude higher than the PFAS compound concentrations with PFOA and trace levels of PFOA into tap water collected from Riverside, California. The concentration profiles, H 2 - The tuned VUV photochemical system was shown to efficiently reduce the levels of PFOA and PFOS in tap water within short reaction times. Specifically, after 30 minutes of irradiation, the concentration of PFOA decreased dramatically from 1300 to 65 ng / L, and the concentration of PFOS decreased significantly from 580 ng / L to 66 ng / L. Over 95% of the PFAS compounds were removed from tap water within 45 minutes.

[0048] Meaning A tunable VUV photochemical system using hydrogen gas and a special reactor design was developed to create a highly reducing environment for destroying PFAS, and excellent efficiency for PFOA removal under various hydrochemical conditions was demonstrated. Additional research found that the VUV photochemical system also has excellent performance for treating more recalcitrant PFAS compounds, namely PFOS. Compared to the benchmark UV / sulfite system, H 2 since a clean H 2 is used instead of sulfite in the saturated VUV photochemical system, the introduction of sulfate into the solution is eliminated, and higher defluorination and minimization of the formation of recalcitrant intermediates can be achieved. Considering that the irradiance of effective VUV light at 185 nm is only 8% of the UV irradiance at 254 nm, the VUV photochemical system is more energy-efficient than the UV / sulfite system. By applying a light source with high UV irradiance in the VUV region, the treatment and energy efficiency of the newly developed system can be significantly improved. The VUV photochemical system can be used as a large-scale throughput flow-through reaction system for PFAS-impacted drinking water sources and concentrated waste streams containing PFAS generated from membrane separation and ion exchange processes.

[0049] Any publications, patents, and patent applications are hereby incorporated by reference as if each were individually incorporated by reference. The present invention has been described with reference to various specific preferred embodiments and techniques. However, it should be understood that many changes and modifications are possible within the spirit and scope of the present invention.

Claims

1. A method comprising treating an aqueous solution containing a contaminant under reducing conditions with ultraviolet light having a wavelength of 230 nm or less to remove at least 75% of the contaminant from the solution.

2. The method according to claim 1, wherein the reducing conditions include hydrated electrons.

3. The method according to claim 1 or 2, wherein the reducing conditions include a highly polarized reducing environment generated by an adjustable chemical substance.

4. The method according to any one of claims 1 to 3, further comprising adding an adjustable chemical substance as an electron-donating solute to the aqueous solution containing the contaminant.

5. The method according to claim 4, wherein the electron-donating solute is selected from the group consisting of a gas, an alcohol, and a carboxylate.

6. wherein the electron-donating solute is N ２ gas, H ２ The method according to claim 4, selected from the group consisting of gas, ethanol, isopropanol, and formic acid.

7. Providing an aqueous solution containing a contaminant; H ２ adjusting the aqueous solution by adding an adjustable chemical substance selected from the group consisting of alcohol and carboxylic acid; Optionally, adjusting the pH of the adjusted solution to be about 7 to about 12; Irradiating the adjusted solution with UV light having a wavelength of about 100 nm to about 230 nm until at least 75% of the contaminant is removed from the solution, the method according to claim 1.

8. The method according to any one of claims 1 to 7, wherein the contaminant is an organic contaminant, a metal, a metalloid, a nutrient, an oxyanion, a fluorinated compound, a radionuclide, or a microbial contaminant.

9. The method according to claim 8, wherein the organic contaminant is a chlorinated compound, 1,4-dioxane, a pesticide, or a nitroaromatic compound.

10. The method according to claim 8, wherein the metal is hexavalent chromium or pentavalent vanadium.

11. The method according to claim 8, wherein the metalloid is selenium or arsenic.

12. The method according to claim 8, wherein the fluorinated compound is a perfluoroalkyl carboxylate, a perfluoroalkyl sulfonate, or a fluorotelomer.

13. The method according to claim 8, wherein the oxyanion is a nitrate, a bromate, a perchlorate, or a chlorate.

14. The method according to claim 8, wherein the radionuclide contains uranium.

15. The method according to claim 8, wherein the microbial contaminant is a bacterium or a virus.

16. The method according to any one of claims 1 to 15, wherein the aqueous solution or spraying solution has a pH of about 7 to about 12.

17. The method according to any one of claims 1 to 15, wherein the aqueous solution or spraying solution has a pH of from about 2 to about 7.

18. The method according to any one of claims 1 to 15, wherein the aqueous solution or spraying solution has a pH of at least about 8.

19. The method according to any one of claims 1 to 15, wherein the aqueous solution or spraying solution has a pH of at least about 9.

20. The method according to any one of claims 1 to 15, wherein the aqueous solution or spraying solution has a pH of at least about 10.

21. The method according to any one of claims 1 to 15, wherein the aqueous solution or spraying solution has a pH of at least about 11.

22. The method according to any one of claims 1 to 21, wherein at least 85% of the contaminants are removed from the solution.

23. The method according to any one of claims 1 to 21, wherein at least 90% of the contaminants are removed from the solution.

24. The method according to any one of claims 1 to 21, wherein at least 95% of the contaminants are removed from the solution.

25. A method comprising irradiating an aqueous solution containing contaminants with vacuum ultraviolet light in a highly polarized reducing environment.

26. The method according to claim 25, wherein an adjustable chemical is added to the aqueous solution to provide the highly polarized reducing environment.

27. The method according to claim 26, wherein the adjustable chemical is selected from the group consisting of gases, alcohols, and carboxylates.

28. wherein the adjustable chemical substance is N ２ gas, H ２ The method according to claim 26, selected from the group consisting of gas, ethanol, isopropanol, and formic acid.

29. A method comprising irradiating an aqueous solution containing contaminants with vacuum ultraviolet light and bubbling a gas into the aqueous solution.

30. The method according to claim 29, wherein irradiating the aqueous solution containing the contaminants with the vacuum ultraviolet light comprises flowing a gas through a high vacuum ultraviolet transmissive quartz sleeve containing an electromagnetic radiation source.

31. Flowing the gas through the high-vacuum ultraviolet-transmissive quartz sleeve that houses the electromagnetic radiation source includes flowing N ２ The method according to claim 30, including flowing a gas.

32. The method according to claim 29, wherein bubbling the gas into the aqueous solution comprises spraying the gas into the aqueous solution, or converting the gas into nanobubbles and injecting the nanobubbles into the aqueous solution, and / or bubbling the gas into the aqueous solution substantially continuously.

33. Substantially continuously bubbling the gas into the aqueous solution involves introducing H into the aqueous solution ２ The method according to claim 32, comprising substantially continuously bubbling the gas.

34. The method according to claim 29, further comprising cooling the aqueous solution.

35. The method according to claim 34, further comprising adjusting the pH of the solution having a pH to be about 7 to about 12.

36. The method according to claim 34, further comprising adjusting the pH of the solution having a pH to be about 2 to about 7.

37. The method according to any one of claims 1 to 36, wherein the aqueous solution is drinking water.

38. The method according to any one of claims 1 to 36, wherein the aqueous solution is industrial waste.

39. The method according to any one of claims 1 to 36, wherein the aqueous solution is hazardous waste.

40. A container for holding an aqueous solution containing contaminants, a high vacuum ultraviolet transmissive quartz sleeve housing and an electromagnetic radiation source for providing vacuum electromagnetic radiation to the aqueous solution, An apparatus comprising.

41. The apparatus according to claim 34, further comprising a cooling structure thermally coupled to the container.

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