Patent Application
20240399432
The present disclosure relates to an improved treatment systems and methods for removing, isolating, or separating a substance from water or aqueous solutions. In particular, the present disclosure relates to the separation of perfluoroalkyl or polyfluoroalkyl substances from water. Embodiments of the present disclosure can also be applied can also be applied to the removal of non-organic materials or contaminants from all types of contaminated water sources. In particular, the present disclosure relates to the separation and removal of perfluoroalkyl or polyfluoroalkyl substances, volatile organic compounds, non-organic materials, or other contaminants from all types of contaminated water sources.
The systems, methods, and related apparatuses of the present disclosure relate to the removal of contaminants through the use of foam fractionation processes with gas recycling capabilities.
Moreover, the system, method, and related apparatuses of the present disclosure relates to the removal of contaminants from a contaminated water source through the use of foam fractionation processes. More particularly, aspects and embodiments of the present disclosure disclosed herein are related to a sustainable and efficient removal and elimination of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from water using continuous, multistage foam fractionation processes.
In some embodiments, aspects and embodiments of the present disclosure disclosed herein are related to a sustainable and efficient removal and elimination of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from water using foam fractionation processes with flexibility to meet required flexibility to meet output requirements in terms of concentration, flow, and combinations thereof.
Moreover, the system, method, and related apparatuses of the present disclosure relates to the removal of contaminants from a contaminated source through the use of foam fractionation processes. More particularly, aspects and embodiments of the present disclosure disclosed herein are related to a sustainable and efficient removal and elimination of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from water using continuous, multistage foam fractionation processes.
Further, the present disclosure relates to the removal of total organic carbon from PFAS-contaminated sources during the process of destroying the PFAS in the contaminated source.
In particular, the present disclosure relates to the separation of perfluoroalkyl or polyfluoroalkyl substances from water, as well as non-organic materials and contaminants found in various water sources affected by industrial, municipal, or natural processes. Embodiments of the present disclosure can also be applied can also be applied to the removal of non-organic materials or contaminants from all types of contaminated water sources.
Moreover, the system, method, and related apparatuses of the present disclosure relate to the removal of contaminants from a contaminated water source through the use of foam fractionation processes. More particularly, aspects and embodiments of the present disclosure disclosed herein are related to a sustainable and efficient removal and elimination of perfluoroalkyl and polyfluoroalkyl substances (PFAS) from water using continuous, multistage foam fractionation processes. Within the context of environmental remediation, this disclosure emphasizes the use of continuous, multistage foam fractionation processes to produce a PFAS-rich foam and chemically reactive agents such as calcium oxide (CaO) or magnesium oxide (MgO) with enhanced reactivity to produce a pollutant free stream.
Furthermore, the present disclosure relates to destruction of contaminates with reactive oxides. In particular, the present disclosure includes systems and methods for the destruction of contaminated sources, such as containers, streams, and soils, by using the processes for destruction of PFAS compounds via mineralization with reactive oxides.
None.
Perfluoroalkyl and polyfluoroalkyl materials (PFAS) are a class of compounds that have been used in the manufacture of consumer and industrial chemicals. The PFAS chemical class comprises thousands of human-made chemicals. In fact, current estimates by the Organization for Economic Cooperation and Development (“OECD”) predict that there are over 4,700 distinct PFAS chemicals. The most commonly utilized PFAS are perfluorooctanoic acid (“PFOA”) and perfluorooctane sulfonic acid (“PFOS”).
The feature that makes all of these chemicals fall within the class of PFAS is a particular kind of bond present within the chemical. Specifically, each of these chemicals has at least one atom of carbon bound to a fluorine atom (a C—F bond). This short polar-covalent chemical bond makes these substances extremely strong. Most PFAS—including the once commonly utilized chemicals of PFOA and PFOS—break down exceptionally slowly and remain in the environment, leading to PFAS being noted as “forever chemicals.”
For a longstanding period of time, the public was unaware of the toxicity of PFAS. In stark contrast to the environmental hazard that PFAS are currently viewed as posing, PFAS were considered a useful addition to the commercial industry when first introduced in the 1940s. PFAS were durable, resistant to extreme temperatures, hydrophobic, and oleophobic. Because of these qualities, PFAS were quickly incorporated into a variety of products: microwavable food packaging, stain-resistant carpet coating, Teflon cookware, and firefighting foam.
Mass amounts of these products were manufactured and subsequently stored or disposed of worldwide. In particular, aqueous film-forming foams (AFFF) has been used extensively as a fire suppressant. In fact, AFFF was a longstanding primary fire suppressant utilized by global military fire training bases. AFFF works by covering a fuel spill, cooling surfaces, and preventing re-ignition. After product use, PFAS would disperse into the ecosystem. In particular, the AFFF, when used for training firefighters, military use, and at-home fire protection, were intentionally routed to run-off to the nearest water system. These practices resulted in PFAS deposits into soil, rivers, lakes, well water and drinking water.
The widespread, long-term use of PFAS compounds in products such as firefighting foams has led to extensive contamination of soil and groundwater. But, there are also situations in which a small area of soil may quickly become highly contaminated, such as for instance, if a few buckets of AFFF were spilled. In these situations, there is a need for a system that can quickly and efficiently destroy PFAS directly in a small quantity of highly contaminated soil.
PFAS has been proven toxic when introduced into the human body. PFAS introduced into the body through ingestion of drinking contaminated water will not decompose and instead will bioaccumulate. The bioaccumulation results in PFAS entering the bloodstream, which can result in long-term, adverse health effects in humans, such as cancer, and developmental health effects, such as low birth weight.
Moreover, beyond human effects, PFAS can contaminate animal bloodstreams as well. PFAS has been found in mammals' milk and animal offspring, leading to dairy farm shutdowns. The consumption of contaminated milk, from either humans or other mammals exposed to PFAS, by babies and young children was also shown to lead to negative developmental health effects.
In 2016, the U.S. Environmental Protection Agency (EPA) issued the following Health Alerts (HA) for PFOA and PFOS: the sum of the individual components and concentrations for PFOS and PFOA, respectively, is 0.07 .mu.g/L. In response to the increasing harms being linked to PFAS, the United States Agency for Toxic Substances and Disease Registry conducted a study on the health effects of PFAS and developed estimate minimal risk levels for common PFAS. The study revealed that even low concentrations of PFAS may be associated with adverse health outcomes. In particular, the study noted that drinking water containing concentrations for PFOA of 78 parts per trillion (ppt) for adults and 21 ppt for children, and for PFOS of 52 ppt for adults and 14 ppt for children, would lead to health problems.
While the harms associated with PFAS are now recognized, addressing and correcting the problems associated with PFAS remains a difficulty—especially when attempting to handle the decontamination of PFAS-contaminated sources in large quantities. Because of PFAS's extreme stability, based on the above-mentioned carbon-fluorine bonds, the PFAS contaminants are highly resistant to degradation. Accordingly, to decontaminate exposed water and aqueous solutions, processes must involve targeted removal of PFAS.
Most of the available conventional water treatment systems and methods of removing PFAS from water have proven ineffective. Specifically, conventional systems and methods that attempt to remove PFAS also include biological treatment, air stripping, reverse osmosis and advanced oxidation. All of these conventional techniques are inefficient and often are extremely expensive in practice.
Foam fractionation is a chemical process in which hydrophobic molecules are preferentially separated from a liquid solution using rising columns of air bubbles, with a resulting foam layer on top of the solution trapping the hydrophobic molecule. In general two mechanisms provide for effective removal of molecules from a solution, first a target molecule adsorbs to a bubble surface, and then the bubbles travel up a column and form a foam layer on top which can be collected and disposed of.
Further, streams containing volatile organic compounds can also contaminate aqueous sources after such compounds are produced by industrial processes. The contamination from volatile organic compounds may arise from the transfer of liquids from one containment body to another due to the displacement of air or liquid, by their volatilization during the industrial process, or by contaminated soil remediation or other environmental cleanup operations. Air used in processes for the removal of volatile organic compounds may become saturated with vapors containing volatile organic compounds that can cause environmental damage or health issues if released into the atmosphere.
Foam fractionation predominantly removes surfactant contaminant molecules (molecules that have polar and non-polar ends). At the air-water interface of the bubbles the surfactant molecules orientate themselves so that the non-polar hydrophobic end of the surfactant molecules is in air and the polar hydrophilic end of the molecule is in water. As the bubbles rise to the top of the fractionating column they remove the contaminants and settle at the top of the column as a foam.
Many organic substances can be removed by foam fractionation and larger biological material, such as algae, bacteria and viruses can also be removed. Particles present in the water can also be removed. Inorganic material can also be removed based on the formation of a bond between the inorganic material with the organic matter or a surfactant in the water. For example, calcium carbonate and calcium phosphate complexes can collect organic matter in the water forming micro-flocs that can get trapped in the film surrounding the air bubbles. Metal ions can also form ligands with organic molecules, and glycoproteins have a high affinity for trace metals and therefore facilitate removal of metal ion species from water.
Efficient contaminant removal is complex and depends on many factors including air to water ratio; column height; air bubble diameter; air/water contact time; air bubble flow rate; foaming agent; foam wetness; downward water flow rate; foam stability; and collision speed between the water and the rising gas. Foam stability is also an important factor and can be defined as the resistance to water and contaminant drainage from the foam, without foam rupturing. The foam must be stable enough to be removed from the fractionating column, without leaching of the contaminant molecules into the water.
Efforts to use foam fractionation for the removal of PFAS contaminants often relies on batch processes, which can prove difficult to both scale and to operate. When attempting to scale batch processes for using foam fractionation to remove PFAS from water and aqueous solutions, operators are necessary to control feedback and intervention in the process. Moreover, those using foam fractionation systems are in need of a flexible system that can meet their output requirements in terms of concentration, flow, or a combination thereof. Moreover, those using foam fractionation systems are in need of a flexible system that can meet their output requirements in terms of concentration, flow, or a combination thereof.
Additionally, foam fractionation often requires large volumes of foam-forming gas. Foam fractionation processes typically use compressed air in a pass-through mode, in which air is used only once to form a foam and then the air is vented to atmosphere.
The single use of air poses significant problems because the vented air may be contaminated with volatile water pollutants. For instance, the single use may contain short carbon chain PFAS compounds, other volatile organic compounds, or combinations thereof. Prevention of the release of contaminant compounds into the atmosphere requires the costly addition of an air purification method.
Moreover, the single use of air in a foam fractionation system poses significant problems because of the processing of volatile or flammable liquid streams, for instance water mixed with solvents, using air can be dangerous. While the use of inert gases would lead to a safer system, these gases are prohibitively expensive to use only once and then vent in a process to produce foam.
Accordingly, there is a need to develop a PFAS removal system and method that can extract, separate, or isolate PFAS from water or aqueous solutions in a manner that is effective, low-cost, scalable, and safe to operate. There is also a need to develop a mobile system that can be controlled in terms of flow capacity and concentration capability. Specifically, there is a need to develop a PFAS removal system and method that can extract, separate, or isolate PFAS from water or aqueous solutions in a manner that is effective, low-cost, scalable, and safe to operate. There is also a need to develop a mobile system that can be controlled in terms of flow capacity and concentration capability.
Moreover, PFAS and PFOA destruction also may pose challenges related to concentration, functional groups, and co-contaminants in the materials requiring treatment. Prior practices have often led to the generation of vapors, corrosion, and undesirable outcomes. There is a need for a system that can eradicate PFAS material without impacting the equipment or the environment, operating at ambient pressure and relatively low temperature, addressing these challenges without the need for exotic materials of construction or high energy demand.
In fact, prior practices for PFAS destruction face significant hurdles to widespread adoption and are not suitable for all types of PFAS-contaminated waste. For example, supercritical water oxidation (SCWO) suffers from corrosion and plugging issues if the influent contains certain problematic contaminants or solids. Combatting this problem requires filtering, costly consumables, and analytical testing, as well as preventive maintenance downtime and careful batch testing. Electrochemical methods can consume large amounts of energy and have the potential to form toxic byproducts. Moreover, in many situations, such as with the plastic buckets that are used to store aqueous film-forming foam (AFFF), it is not feasible to clean containers sufficiently such that they can be re-used or discarded in a regular landfill. Therefore, a versatile, scalable, cost-effective system that destroys PFAS without producing toxic byproducts is needed.
In fact, prior practices for PFAS destruction face significant hurdles to widespread adoption and are not suitable for all types of PFAS-contaminated waste. For example, supercritical water oxidation (SCWO) suffers from corrosion and plugging issues if the influent contains certain problematic contaminants or solids. Combatting this problem requires filtering, costly consumables, and analytical testing, as well as preventive maintenance downtime and careful batch testing. Electrochemical methods can consume large amounts of energy and have the potential to form toxic byproducts. Moreover, in many situations, such as with the plastic buckets that are used to store aqueous film-forming foam (AFFF), it is not feasible to clean containers sufficiently such that they can be re-used or discarded in a regular landfill. Therefore, a versatile, scalable, cost-effective system that destroys PFAS without producing toxic byproducts is needed.
Accordingly, there is a need to develop a PFAS removal system and method that effectively, affordably, and safely extracts, separates, or isolates PFAS from water or aqueous solutions, while also addressing the destruction of PFAS in containers such as plastic buckets used for storing AFFF. As such, there is a need for a system capable of handling both large-scale and small-scale contaminations, ensuring minimal environmental and equipment impact.
Accordingly, there is a need to develop a PFAS removal system and method that can extract, separate, or isolate PFAS from water or aqueous solutions in a manner that is effective, low-cost, scalable, and safe to operate.
Moreover, there exists a need for a system and method for PFAS and PFOA removal from gas and vapor streams that overcomes challenges related to concentration, functional groups, co-contaminants, and undesirable byproducts. Such a system should operate at ambient pressure and relatively low temperature, ensuring minimal equipment and environmental impact. Additionally, it should offer cost-effective and safe removal methods, producing an effluent stream that is essentially inert.
Moreover, the need extends to a system and method for PFAS and PFOA removal from gas and vapor streams, particularly in high-temperature waste treatment systems. When operating at high temperatures, a portion of the PFAS to be treated will end up in the atmosphere of the waste treatment system. Thus, there is a critical requirement for a method to destroy PFAS in the flue gas of high-temperature waste treatment systems to prevent environmental emission. Such a system should operate efficiently at ambient pressure and relatively low temperature, ensuring minimal equipment and environmental impact while offering a cost-effective and safe removal method, producing an effluent stream that is essentially inert.
The present disclosure relates to system and methods for using foam fractionation to remove a PFAS contaminant from a water source. In accordance with one or more embodiments, the systems and methods disclosed herein relate to the separation, concentration, and destruction of PFAS from a source of water that is contaminated with PFAS.
The present invention is, in certain embodiments, directed to a method and system for using a continuous foam fractionation process to remove PFAS from AFFF. From this, in some embodiments, the method and system may be utilized to remove PFAS compounds from highly contaminated streams. In some embodiments, prior to the removal and destruction of the PFAS compounds from the highly contaminated source, the method and system may include the removal of total carbon content from the highly contaminated source, such as AFFF.
In general, in one embodiment, the disclosure features a system for the destruction of PFAS compounds through mineralization with reactive oxides. The system includes an acquisition unit for obtaining reactive oxides; a mixing unit operatively connected to the acquisition unit, where the mixing unit is configured to combine PFAS-contaminated waste with the reactive oxides. The system also includes a high-temperature treatment unit operatively connected to the mixing unit, where the high-temperature treatment unit is configured to subject the mixture of PFAS-contaminated waste and reactive oxides to a chemical reaction. The system also includes a cooling unit operatively connected to the high-temperature treatment unit, where the cooling unit is configured to cool the mixture post high-temperature treatment to create a cooled mixture. The system also includes a waste collection receptacle connected to the cooling unit, where the cooled mixture is directed for disposal. The system also includes one or more particulate vapor treatment systems connected to the high-temperature treatment unit and the cooling unit, where PFAS-contaminated atmospheres from the high-temperature treatment unit and the cooling unit are captured to prevent emissions to the environment.
In general, in another embodiment, the invention features a method for treating highly contaminated soil using a PFAS mineralization system. The method includes obtaining a quantity of highly contaminated soil, where the highly contaminated soil comprises PFAS compounds. The method also includes mixing the obtained soil with reactants selected from the group consisting of oxides, hydroxides, or a combination thereof. The method also includes placing the mixture into a high-temperature treatment unit to allow for chemical decomposition of the PFAS compounds, where the placing the mixture into a high-temperature treatment unit results in a treated mixture. The method also includes cooling the treated mixture to create a cooled mixture. The method also includes disposing of the cooled mixture.
In general, in one embodiment, the disclosure features a method for the destruction of AFFF and other wastes containing PFAS compounds. The method includes introducing a contaminated source, where the contaminated source includes PFAS contaminants, non-PFAS contaminates, and an aqueous solution. The method also includes oxidizing the non-PFAS contaminates in the introduced contaminated stream, thereby leaving most of the PFAS contaminants in their original form and decomposing non-PFAS contaminants present in the contaminated stream. The method also includes utilizing foam fractionation-based separation and concentration of PFAS compounds. The method also includes, resultant from utilizing foam fractionation-based separation, producing a first stream comprising concentrated PFAS compounds and a second stream comprising purified water. The method also includes destroying the concentrated PFAS compounds in the first stream.
In general, in another embodiment, the disclosure features a method for removing total organic carbon (TOC) prior to supercritical water oxidation of a contaminated stream, the method including introducing a contaminated stream including PFAS contaminants and non-PFAS contaminants, where the non-PFAS contaminants include TOC. The method also includes diluting the introduced stream to a level suitable for measuring the TOC. The method also includes applying an applied amount of UV radiation to reduce a content of the TOC; oxidizing the non-PFAS contaminants, leaving most of the PFAS compounds in the contaminated stream.
Other advantages of the present invention will be apparent from the following detailed description of the invention in conjunction with embodiments as illustrated in the accompanying drawings, in which:
The present disclosure relates to system and methods for using foam fractionation to remove a PFAS contaminant from a water source. In accordance with one or more embodiments, the systems and methods disclosed herein relate to the separation, concentration, and destruction of PFAS from a source of water that is contaminated with PFAS.
As discussed above, the man-made PFAS chemical compounds are highly stable because of the mentioned carbon-fluorine bonds, which are longstanding and do not readily decompose in the environment. Additionally, PFAS—especially PFAS from products in which it was used as a repellant and protective coating—has cumulated in various water supplies. Even with largescale efforts to phase out the use of PFAS compounds, elevated levels of the “forever chemicals” remain present throughout the environment. PFAS may be found in areas near prevalent uses of prior PFAS products (such as near fire training facilities) and in locations where PFAS has migrated through water and air.
In some non-limiting embodiments, prevalent PFAS, such as PFOS and PFOA, may be removed from water using the methods and systems disclosed herein.
Additionally, based on the EPA's revised guidelines published in May 2016 and recent regulation efforts, water distribution and filtering facilities are now aware of the limits of a combined lifetime exposure of 70 parts per trillion (ppt) for PFOS and PFOA. In some cases, the systems described herein can maintain a concentration of PFAS in treated water to be below the regulated and advised levels.
In certain embodiments, the overall process, can be characterized by taking a PFAS-concentration of at least 100 ppm PFAS by weight (in some embodiments at least 500 ppm or at least 1000 ppm PFAS) to 1 ppm or less, or 0.1 ppm or less, or 0.01 ppm or less. Alternatively, by taking a PFOA-concentration of at least 100 ppm PFOA by weight (in some embodiments at least 500 ppm or at least 1000 ppm PFOA) to 1 ppm or less, or 0.1 ppm or less, or 0.01 ppm or less, or 1.0 ppb or less, or 0.1 ppb or less, or 0.01 ppb or less PFOA; in some embodiments in the range of 1 ppm to 5 ppt (part per trillion) PFOA. Alternatively, by taking a PFOS-concentration of at least 100 ppm PFOS by weight (in some embodiments at least 500 ppm or at least 1000 ppm PFOS) to 1 ppm or less, or 0.1 ppm or less, or 0.01 ppm or less, or 1.0 ppb or less, or 0.1 ppb or less, or 0.01 ppb or less PFOS; in some embodiments in the range of 1 ppm to 5 ppt (part per trillion) PFOS. The process can also be characterized by the same levels of destruction beginning with a PFAS concentration of less than 100 ppm. In some embodiments, PFAS-contaminated water comprising at least 1000 ppt of at least one (or at least 3 or at least 4 or at least 5 or at least 6) compound selected from the group consisting of PFHxA (perfluorohexanoic acid), PFHpA (perfluoroheptanoic acid), PFOA, PFBS (perfluorobutane sulfonate), PFHxS (perfluorohexane sulfonate), PFHpS (perfluoroheptane sulfonate), and PFOS and combinations thereof, treated by the process is (are) reduced by at least 2 (or at least 3 or at least 4 or at least 5) orders of magnitude. In some embodiments, PFAS-contaminated water comprising at least 100 ppt of at least one (or at least 3 or at least 4 or at least 5 or at least 6) compound selected from the group consisting of PFBA (perfluorobutanoic acid), PFPeA (perfluoropentanoic acid), PFHxA, PFHpA, PFOA, 6:2 FTS (6:2 fluorotelomer sulfonate), and 8:2 FTS (8:2 fluorotelomer sulfonate) and combinations thereof, treated by the process is (are) reduced by at least 2 (or at least 3 or at least 4 or at least 5) orders of magnitude and/or reduced to 5 ppt (or 1 ppt) or less.
In some embodiments, separation of PFAS from a source of contaminated water may be achieved using foam fractionation. In such an embodiment, and in accordance with the system shown in
In some embodiments, the gas introduced to the system of
In some embodiments, the gas is introduced from the base of the container that houses the contaminated water. Further, in some embodiments, the pressure of the container can operate to facilitate the movement of the gas bubbles through the contaminated water and help to form a foam layer.
Further, as depicted in
Further, in some embodiments, the system can discharge the feed stream, which can then be referred to as the cleaned stream, once it has a sufficient amount of the PFAS removed. For example, in some embodiments, the cleaned stream can be removed from the system when there is less than 70 parts per trillion (i.e., below the regulatory recommended amount from the EPA's guidance) of PFAS remaining in the cleaned stream. In certain embodiments, the final amount of PFAS left in the cleaned stream may be 1 ppm or less, or 0.1 ppm or less, 0.01 ppm or less, 0.001 ppm (1 ppb) or less, 0.0001 ppm (0.1 ppb) or less, 0.00001 ppm (0.01 ppb) or less, or 0.000001 ppm (0.001 ppb or 1 ppt) or less.
As is also shown in
In the embodiment depicted in
In some embodiments, the system as depicted in
In some embodiments, where the later columns in the system generate an insufficient amount of foam due to depletion of surfactant from the feed stream in the earlier columns, the system and process can further include adding additional surfactant into various columns throughout the system, which ensures that sufficient surfactant is present in all columns of the system. In such an embodiment, there can be a significant benefit of allowing for the addition of more columns to the system. Accordingly, in some embodiment, the foam fractionation system include ports for surfactant addition throughout the foam fractionation columns to achieve the target separation.
As shown in
In some embodiments, surfactants can also be effectively utilized for the destruction of AFFF. In such embodiments, by introducing specific surfactants at various stages within the foam fractionation system, the breakdown and removal of these contaminants in AFFF can be significantly enhanced. The surfactants can be particularly useful in treating the complex mixture of pollutants found in AFFF, ensuring that PFAS levels are reduced to safe limits before the treated water is reintroduced into the environment.
In some embodiments of the system, once a contaminated water source is identified, the contaminated water source is then fed to the system in a feed stream, as is shown in
In some embodiments, the system of
In some embodiments, the foam fractionation system of
In some embodiments, the specific requirements include, but are not limited to, the amount of wastewater to be processed, the flow at which the processing needs to be carried out, and a degree of PFAS concentration required.
There can be a variety of possible arrangements for the process, one embodiment of such process shown in
A preferred system 300 is illustrated in
The oxidant 324 can be in either stream 302 or 306. In preferred embodiments, the oxidant 324 is in stream 306 to prevent premature reaction. Combined stream 308 passes into Supercritical Water Oxidation (SCWO) reactor 310. In some embodiments, the SCWO reactor 310 is a vertical tube, in respect to gravity, surrounded by insulation and heating means for start-up. Temperature in the SCWO reactor 310 in certain embodiments is in the range of 500 to 700° C.
The effluent 312 can passes into a salt separator 314 where salt can be removed manually or through exhaust system 316. In such an embodiment, the system is left as brine 318. Salt can be a mixture of sodium chloride, sodium fluoride, sodium sulfate, sodium nitrate or corresponding salts of other alkali or alkaline earth elements.
Fluid 320, in certain embodiments, leaves the separator and is routed through a heat exchanger 322, in the direction indicated such that temperature of fluid 320 is highest where the clean water 306 leaves the heat exchanger.
In some embodiments, after passing the heat exchanger, the clean water 306 may optionally be passed through heater 326 to heat the water to 600° C. or higher. After passing through the heat exchanger, effluent 328 can leave the system and optionally be neutralized at any point after exiting the SCWO reactor 310. In some embodiments, all or a portion of the effluent can also be recycled into the system and/or released into the environment or a water treatment facility.
Referring to
As shown in
At step 404, the method includes introducing the feed stream into an interior of the active column. For example, in such an embodiment, the feed stream can be housed within a column for foam fractionation. At step 406, the method includes flowing gas through a base of the active column into the interior of the active column. In some embodiments, the gas may be introduced via a porous gas nozzle. In certain embodiments, the gas may be introduced via a venturi device where the compressed gas drives water flow, which in turn can mix the gas and water streams. In other embodiments, the gas may be introduced via a water vacuum pump device where water flow generates suction that introduces gas stream into a water stream. Moreover, in some embodiments, the gas can be introduced near an impeller, a mixer, or a combination thereof to generate gas-water mixing.
The gas, in certain embodiments, may be compressed air, oxygen, nitrogen, carbon dioxide, or combinations thereof. In some embodiments, the gas may be any gaseous phase chemical composition that will allow for contaminant adsorption on the surface of gas bubbles of the gas.
At step 408, the method includes, as a result of the flowing of the gas into the interior of the active column, rising gas through the feed stream in the interior of the active column to form gas bubbles in the feed stream.
At step 410, as a result of the gas bubbles in the feed stream, the method includes forming a foam layer. In some embodiments, the foam layer is situated atop the feed stream in the interior of the active column. In certain embodiments, the foam layer can include at least a part of the PFAS contaminant that was initially present in the feed stream. After the foam layer is formed, in some embodiments, the interior of the active column can include both the foam layer and a purified stream, where the purified stream is the result of the PFAS contaminant being removed from the feed stream.
At step 412, the method includes passing the purified stream into a next column. In some embodiments, the next column operates as the active column and the purified stream operates as the feed stream.
Following, at decision block 414, the method progresses to determine whether the solution flowing through the system as the filtered stream contains a sufficiently low level of contaminant to result in a cleaned stream. In some embodiments, the decision block 414 determinations are decided prior to the construction of a system for conducting the method 400. In such an embodiment, the calculation of the quantity of PFAS contaminant removed at each column can be performed. In this embodiment, based on the calculation, the system is designed to contain the number of columns that will achieve a cleaned stream containing a sufficiently low level of contaminant. Such an embodiment will have a static number of columns that the feed stream and/or filtered stream will pass through in the system.
If the decision at block 414 is negative (i.e., the purified stream contains an amount of PFAS that may pose a health risk or is greater than a pre-determined amount of PFAS contaminant), then the method restarts at step 404.
If the decision at block 414 is affirmative (i.e., there is a sufficiently minimal amount of PFAS remaining in the purified stream such that the water in the stream does not pose either a health risk or is less than a pre-determined amount of PFAS contaminant), then the method continues to step 416. In some embodiments, as the number of columns in the system performing the method is predetermined, the decision at block 414 does not change the architecture of the system performing method 400.
At step 416, the method includes collecting the foam layer. At step 418, the method includes disposing of the foam layer.
As shown in
The number of systems in parallel determines the total flow capacity, as shown in
In some embodiments, as shown in
In certain embodiments, the system can include modular components that may be freely movable, such that the modular components allow portions of the foam fractionation system to be taken out of a housing and expanded in number to increase flow or concentration as needed on site. In such an embodiment, the process can involve placing the foam fractionation columns on modular skids that can be fit into housings and taken out as needed. As shown by
In some embodiments, the system for foam fractionation can include a containerized system with external skids. Such a system could be deployed to increase either concentration or flow. Further, such an embodiment can be utilized to provide temporary increase in capability. In some embodiments, the system could be utilized to progressively increase the capacity of a system as need increases. Moreover, in some embodiments, the system may increase concentration where destruction is not available to save on storage space until destruction of the PFAS contaminants is available.
As shown earlier in respect to
In some embodiments, to increase effective foam fractionation, the process can produce and utilize a relatively dry foam. A dry foam can increase the efficiency of the foam fractionation because the concentration of the target molecules in the foamate is maximized when the volume of water is minimized. Moreover, drainage from bubble breakage increases solute concentrations in the foam due to the elevated solute concentrations in liquid that originates from bubbles.
Accordingly, as shown in
As shown in
The process of
In certain embodiments, the UV would include oxidants. In some embodiments, the process can include using a UV (185 nm) with peroxide or ozone. In other embodiments, the UV can be used without oxidants. In some embodiments, the process can include using a UV (185 nm) solely. In other embodiments, the process may include using UV emitting 15 nm to 220 nm with ammonium or sodium persulfate.
In some embodiments, the oxidation step can leave all or most of PFAS compounds in their original form but will decompose the non-PFAS surfactants and solvents present in the AFFF. In certain embodiments, the oxidation does not affect inorganic materials that may be introduced by use of hard water in AFFF formulations.
Following the oxidation, as shown in
As discussed in respect to
For the highly concentrated PFAS stream or foam, the process may continue with the destruction of the PFAS compounds by either supercritical water oxidation, in accordance with
In some embodiments, the disposal of the foam layer is through the treatment of the PFAS/PFOA-contaminated foam stream using a reactive metal oxide.
PFAS and PFOA compounds can be decomposed using calcium compounds at moderate temperatures of 300-700° C., with the reaction producing non-toxic calcium fluoride (CaF2) as a main solid product. The general reaction between PFAS/PFOA compounds and calcium oxide can be described as:
PFAS/PFOA+CaO→CaF2+H2O+CO2+immobilized solid products
In certain embodiments, the reaction does not require elevated pressures and there is no evidence of corrosion caused by formation of hydrofluoric acid (HF).
Furthermore, the synthesis of calcium oxide (CaO) with enhanced chemical reactivity can maximize its effectiveness in PFAS destruction. Methods such as thermal decomposition of calcium hydroxide (Ca(OH)2) at 400-500° C. have been established to produce highly reactive CaO, a crucial factor in efficient PFAS removal.
Accordingly, in embodiments of the present disclosure, calcium hydroxide (Ca(OH)2) can serve as a decomposing agent for PFAS, and this equivalence enables the development of PFAS destruction processes using both CaO and Ca(OH)2. Additionally, magnesium oxide (MgO) shares similar chemical properties with CaO, providing an alternative for PFAS removal processes. Reactive MgO can be produced through the thermal decomposition of magnesium hydroxide (Mg(OH)2) at around 400-500° C., offering potential utility in PFAS elimination.
Significantly, the method of the present disclosure may operates at atmospheric pressure, eliminating the need for high-pressure equipment and associated safety concerns. Furthermore, the risk of corrosion due to hydrofluoric acid (HF) formation can be significantly reduced or eliminated. The mineralization process effectively converts fluorine into CaF2, a non-corrosive solid, negating the requirement for expensive, corrosion-resistant alloys. Beyond PFAS/PFOA treatment and destruction, this process displays the capability to decompose various toxic compounds, making it suitable for treating complex waste streams containing multiple pollutants.
A general approach to continuously treat PFAS/PFOA contaminated foam streams with reactive metal oxides is presented schematically in
In certain embodiments, such as those where incoming stream is delivered at lower temperature, a suitable heater or heat exchanger can be used to pre-heat the foam contaminated with PFAS/PFOA and other pollutants. In other embodiments, heat may be delivered directly to the reactor. Several types of reactors can be used including packed bed, kiln (calciner) fluidized bed, belt furnace, or spouted bed reactors. The reaction can be carried out at any pressure, for example atmospheric or near atmospheric pressure. Assuming the mineralization system is properly designed, the effluent, pollutant-free gas stream can be released directly to atmosphere. In some cases, a gas effluent purification equipment may be used to further reduce possibility of PFAS releases.
In the first step, shown schematically on
The vessel can be at room or slightly elevated temperature, which both allow for formation of hydroxides via reaction between metal oxide and water. In such an embodiment, the reaction can effectively convert the foam stream into a solid hydroxide mixed with PFAS/PFOA compounds as well as with other pollutant potentially present in the foam form the foam fractionation process.
In some embodiments, the foam immobilization temporarily converts the foam stream into a solid which can be further treated at a later time. Such temporary storage can be convenient for low volume from streams that can be treated periodically once sufficient quantities are collected. As the reaction between metal oxides and water is exothermic, especially if CaO is used, in some embodiments, the system and method further include the application and use of a suitable heat removal mechanism.
In the second step, shown schematically in
The second vessel containing fresh metal oxide, in preferred in embodiments, is heated first to temperature required for PFAS/PFOA compounds, such as for example but not limited to between approximately 300 to 700° C. Once the oxide is heated to this temperature, the oxide will be highly reactive towards PFAS/PFOA and towards other pollutants. At the same time, the oxide loses its reactivity towards water since it is at above the decomposition temperature of its hydroxide form. Accordingly, in such an embodiment, the metal oxide at high temperature acts effectively as a selective reactor/filter, reacting with pollutants but allowing for free passage of water vapor.
In some embodiments, the release of foam components previously immobilized can be realized by a controlled heating of the collection vessel. The process, for example, can release PFAS/PFOA compounds, other pollutants, water vapor, and combinations thereof.
In some embodiments, and as shown in
As shown in
The apparatus may further contain venting, through for example but not limited to a ventilation tube, for venting water steam and the gaseous reaction products. In some embodiments, and displayed in
In collected condensed product can include solid waste, which will be inorganic salt residue produced by evaporation of the aqueous solution containing PFAS/PFOA pollutants. Accordingly, in some embodiments, the pollutant-free solid reaction products may be easily disposed.
A system for destroying PFAS compounds using mineralization with reactive oxides can be used on a wide variety of PFAS-contaminated waste, including but not limited to, concentrated foam from a foam fractionation system, AFFF, soil, water from washing soil, plastic containers that are contaminated with PFAS, or combinations thereof.
As shown in
In some embodiments, such as the embodiment of
The next stage of the process, as shown in
Following, in the process shown in
In the fourth and final block shown in
In some embodiments, once the mixture has been sufficiently cooled, the mixture can be removed from the system and appropriately disposed of. In some embodiments, the mixing, high temperature treatment, and cooling steps could all be performed within a single equipment vessel, such as a kiln of sufficient length.
The size and type of equipment selected for the process shown in
The process shown in
As shown in the embodiment of
The system and process of
As shown in
As such, in some embodiments, the treatment of these plastic pieces in this system can occur through a high-temperature process, distinct from incineration. In some embodiments, such a high-temperature process may be performed at atmospheric pressure. This high-temperature treatment can then result in the decomposition of the plastic, contributing to the effective management of PFAS-contaminated materials. Such process represents can be utilized as a safe, environmental responsible, and efficient treatment for contaminated materials.
The system and process of
As shown in
Consistent with the above disclosure, the examples of systems and methods enumerated in the following clauses are specifically contemplated and are intended as a non-limiting set of examples.
Clause 1. A method for using foam fractionation to remove a PFAS contaminant from a water source, the method includes providing a feed stream to an inlet of an active column, where the feed stream comprises the PFAS contaminant and water; introducing the feed stream into an interior of the active column; flowing gas through a base of the active column into the interior of the active column; as a result of the flowing of the gas into the interior of the active column, rising gas through the feed stream in the interior of the active column to form gas bubbles in the feed stream; as a result of the gas bubbles in the feed stream, forming a foam layer, wherein the foam layer is situated atop the feed stream in the interior of the active column, the foam layer comprises at least a part of the PFAS contaminant, and after the foam layer is formed, the interior of the active column comprises the foam layer and a purified stream; passing the purified stream into a next column, wherein the next column operates as the active column and the purified stream operates as the feed stream; continuously repeating foam fraction steps until the feed stream becomes a cleaned stream, wherein a cleaned stream comprises water and at or below a final concentration of the PFAS contaminant; collecting the foam layer; and disposing of the foam layer.
Clause 2. The method of any foregoing clause further including adding an effective amount of a surfactant to the feed stream.
Clause 3. The method of any foregoing clause further comprising, after collecting the foam layer, utilizing the foam layer as the feed stream.
Clause 4. The method of any foregoing clause further including interacting the surfactant the PFAS contaminant to create a complexing agent, where the foam layer comprises the complexing agent.
Clause 5. The method of any foregoing clause, where the PFAS contaminant in the feed stream has an initial PFAS concentration, the at least a part of the PFAS contaminant in the foam layer has removed PFAS concentration, and a remaining PFAS contaminant in the cleaned stream has a final PFAS concentration.
Clause 6. The method of any foregoing clause, where the initial PFAS concentration is equal to that of the removed PFAS concentration added to the final PFAS concentration, and where the removed PFAS concentration is greater than or equal to the final PFAS concentration.
Clause 7. The method of any foregoing clause, where the foam fractionation is continuous.
Clause 8. The method of any foregoing clause, where disposing of the foam layer comprises sending the foam layer to a supercritical water oxidation reactor.
Clause 9. The method of any foregoing clause further including releasing the cleaned stream into an environment.
Clause 10. A system for using foam fractionation to remove a PFAS contaminant from a water source, the system including a feed stream comprising water and one or more contaminants; a gas, where the gas is operable to induce a plurality of bubbles to form in the feed stream, and create a foam layer to form at and above the interface of the feed stream, where the foam layer comprises the one or more contaminants in the feed stream; and a plurality of columns, where each column in the plurality of columns comprises a feed inlet, wherein the feed inlet is configured to receive the feed stream, each column in the plurality of columns is operably configured to separate the one or more contaminants in the feed stream into a foam layer and a purified stream, each column in the plurality of columns comprises a gas inlet, wherein the gas inlet is configured to allow the gas to enter the column, each column in the plurality of the columns comprises a foam outlet, each column in the plurality of the columns comprises a feed outlet, wherein the feed outlet is configured to discharge the purified stream, and each column in the plurality of the columns is coupled to one or more other column in the plurality of the columns to allow a continuous passage of the feed stream through the plurality of columns.
Clause 11. The system of any foregoing clause, where the one or more contaminants comprise PFAS.
Clause 12. The system of any foregoing clause, where the foam outlet is operatively connected to a foam storage tank.
Clause 13. The system of any foregoing clause, where the foam storage tank is operatively connected to a device for destroying the one or more contaminants.
Clause 14. The system of any foregoing clause further comprising a supercritical water oxidation reactor.
Clause 15. The system of any foregoing clause further comprising a removal device for removing at least a portion of the foam layer from each column in the plurality of columns.
Clause 16. The system of any foregoing clause, where the feed inlet is configured to introduce the feed stream into each column in the plurality of columns through an upper region of each column in the plurality of columns.
Clause 17. The system of any foregoing clause, where the feed outlet is configured to introduce the discharge stream into each column in the plurality of columns through a lower region of each column in the plurality of columns.
Clause 18. A method for using foam fractionation to remove a PFAS contaminant from a water source, the method including selecting a feed stream, where the feed stream comprises the PFAS contaminant and water; providing the feed stream to a column, where the column is operatively connected to a series of fractionation columns, the series of fractionation columns perform continuous foam fractionation, and the column and each fractionation column in the series of fractionation columns operate at an operating pressure, where the operating pressure is identical between the column and each fractionation column in the series of fractionation columns; super-saturating the feed stream with air; resultant from the operating pressure of the column, generating a plurality of bubbles in the feed stream; resultant from the generating of a plurality of bubbles, creating a foam layer; collecting the foam layer; and passing the foam layer through a supercritical water oxidation reactor.
Clause 19. The method of any foregoing clause further comprising adding an effective amount of a surfactant to the feed stream.
Clause 20. The system of any foregoing clause further comprising, after collecting the foam layer, discharging a cleaned stream from a final column in the series of fractionation columns.
Clause 21. The system of any foregoing clause, where the PFAS contaminant in the feed stream has an initial PFAS concentration, the foam layer has a removed PFAS concentration, and the cleaned stream has a final PFAS concentration.
Clause 22. The system of any foregoing clause, where the initial PFAS concentration is equal to that of the removed PFAS concentration added to the final PFAS concentration, and where the removed PFAS concentration is greater than or equal to the final PFAS concentration.
Clause 23. The method of any foregoing clause further comprising releasing the cleaned stream into an environment.
Clause 24. A flexible and modular system for utilizing foam fractionation to remove a PFAS contaminant from a water source, the system including a feed stream including water and one or more contaminants; a gas, operable to induce a plurality of bubbles to form in the feed stream, and create a foam layer at and above the interface of the feed stream, where the foam layer includes the one or more contaminants in the feed stream; a plurality of foam fractionation columns, where each column in the plurality of columns includes a feed inlet, configured to receive the feed stream, each column is operably configured to separate the one or more contaminants in the feed stream into a foam layer and a purified stream, each column includes a gas inlet, configured to allow the gas to enter the column, each column includes a foam outlet, each column includes a feed outlet, configured to discharge the purified stream, each column is coupled to one or more other columns to allow a continuous passage of the feed stream through the plurality of columns, and the system is configurable in a variety of arrangements; a plurality of inlet ports, where the system allows for the flow to be routed based on the use of the plurality of inlet ports; and a plurality of modular components, where the plurality of modular components are configured to be removed from a housing to allow for increased concentration.
Clause 25. The system of any foregoing clause, where one or more foam fractionation columns in the plurality of foam fractionation columns are connected in parallel.
Clause 26. The system of any foregoing clause, where the plurality of foam fractionation columns include a number of foam fractionation systems, where the number of foam fractionation systems are physically adjustable to meet a pre-determined need.
Clause 27. The system of any foregoing clause, where the plurality of foam fractionation columns includes a number of foam fractionation systems, where a width established by the number of foam fractionation systems determines the total flow capacity.
Clause 28. The system of any foregoing clause, where the plurality of foam fractionation columns includes a number of foam fractionation systems, where the number of foam fractionation systems in series determines the total degree of water purification.
Clause 28. The system of any foregoing clause, where the plurality inlet ports are configured to affect the flow and increase concentration of the one or more contaminants in the foam layer.
Clause 30. The system of any foregoing clause, where the plurality of foam fractionation columns are oriented to route the flow through additional stages in the multistage process, where the routing allows for increased flow and increased concentration.
Clause 31. The system of any foregoing clause, where the modular components are freely movable.
Clause 32. The system of any foregoing clause, where the modular components allow for one or more foam fractionation columns in the plurality of foam fractionation columns to be taken out of a housing.
Clause 33. The system of any foregoing clause, where the modular components are operatively configured to be received by skids that fit into containers, where the skids are removable from the containers.
Clause 34. The system of any foregoing clause, where removing the foam fractionation columns and portions of the system from a housing allows for increased concentration.
Clause 35. The system of any foregoing clause, further including a containerized system with external skids.
Clause 36. The system of any foregoing clause, where the containerized system with external skids are configured to be deployed to increase either concentration or flow.
Clause 37. The system of any foregoing clause, where the containerized system provides a temporary increase in capability.
Clause 38. The system of any foregoing clause, where the containerized system progressively increases the capacity as need increases.
Clause 39. An angled foam fractionation column for removing one or more PFAS contaminants from a water source, the column comprising: a feed inlet configured to receive a feed stream comprising water, one or more PFAS contaminants, and an effective amount of a surfactant, wherein the surfactant interacts with the PFAS contaminant to form a complexing agent facilitating the removal of light PFAS; a gas inlet configured to allow the entry of a gas operable to induce a plurality of bubbles in the feed stream and create a foam layer at and above the interface of the feed stream, wherein the foam layer comprises the complexing agent and the one or more contaminants; a foam outlet for discharging the foam layer; a feed outlet configured to discharge a purified stream; and a top portion angled at an angle (a) with respect to the vertical axis of the column, wherein the angled top portion decreases the vertical distance a retained water molecule needs to travel, facilitating the drainage of water from the foam and resulting in a more concentrated foamate.
Clause 40. The angled foam fractionation column of any foregoing clause, where the angle (a) of the top portion is approximately 45 degrees to optimize the drainage of water from the foam.
Clause 41. The angled foam fractionation column of any foregoing clause, where the angling of the top portion results in minimizing the volume of water retained in the foam, thereby producing a relatively dry foam.
Clause 42. The angled foam fractionation column of any foregoing clause, where the production of a relatively dry foam increases the concentration of the target PFAS contaminants in the foamate.
Clause 43. The angled foam fractionation column of any foregoing clause, where the increased concentration of PFAS contaminants in the foamate is facilitated by the elevated solute concentrations in the liquid that originates from bubble breakage.
Clause 44. The angled foam fractionation column of any foregoing clause further including a mechanism for injecting compressed air into the liquid phase at the bottom of the column to generate foam.
Clause 45. The angled foam fractionation column of any foregoing clause, where the compressed air induces a plurality of bubbles in the feed stream, creating a foam layer at and above the interface of the feed stream.
Clause 46. The angled foam fractionation column of any foregoing clause, where the foam layer comprises a complexing agent formed by the interaction of the surfactant and the one or more PFAS contaminants, facilitating the removal of light PFAS.
Clause 47. The angled foam fractionation column of any foregoing clause, where the decreased vertical distance a retained water molecule needs to travel due to the angled top portion facilitates the drainage of water, leading to a more concentrated foamate.
Clause 48. The angled foam fractionation column of any foregoing clause, where the column is part of a system comprising a plurality of such columns, each coupled to one or more other columns allowing continuous passage of the feed stream and comprising ports for surfactant addition located throughout various columns to optimize the volume of foam produced in each stage and ensure sufficient surfactant presence.
Clause 49. A system for using foam fractionation to remove a PFAS contaminant from a water source, the system comprising a feed stream comprising water, one or more PFAS contaminants, and an effective amount of a surfactant, wherein the surfactant interacts with the PFAS contaminant to form a complexing agent facilitating the removal of light PFAS; a gas, operable to induce a plurality of bubbles in the feed stream and create a foam layer at and above the interface of the feed stream, wherein the foam layer comprises the complexing agent and the one or more contaminants; a plurality of columns, wherein each column comprises a feed inlet configured to receive the feed stream and a gas inlet configured to allow the gas to enter, each column is operably configured to separate the contaminants into a foam layer and a purified stream, each column comprises a foam outlet and a feed outlet configured to discharge the purified stream, each column is coupled to one or more other columns allowing continuous passage of the feed stream, the plurality of columns comprise a plurality of ports for surfactant addition, wherein the plurality of ports are located throughout various columns in the plurality of columns to optimize the volume of foam produced in each stage and ensure sufficient surfactant presence, and the plurality of ports for adding surfactants are installed in a configuration enabling the addition of surfactants at different columns, such as every other column.
Clause 50. The system of any foregoing clause, where the system is adaptable to incorporate different surfactant amounts and/or types at different points, enabling the addition of more columns for enhanced separation.
Clause 51. The system of any foregoing clause, where at least one column in the plurality of columns comprises an angled top portion, where the angled top portion is disposed at an angle (a) with respect to the vertical axis of the column, facilitating the drainage of water from the foam and resulting in a more concentrated foamate; the decrease in vertical distance a retained water molecule needs to travel due to the angled top portion enhances the efficiency of foam fractionation by maximizing the concentration of target molecules in the foamate; and the angle (a) is configured to minimize the volume of retained water in the foam, thereby producing a relatively dry foam and increasing solute concentrations in the foamate from the drainage of bubble breakage; and
Clause 52. The system of any foregoing clause, wherein the angle (a) is approximately 45 degrees.
Clause 53. A method for the destruction of AFFF and other wastes containing PFAS compounds, the method including: introducing a contaminated source, where the contaminated source includes PFAS contaminants, non-PFAS contaminates, and an aqueous solution; oxidizing the non-PFAS contaminates in the introduced contaminated stream, thereby leaving most of the PFAS contaminants in their original form and decomposing non-PFAS contaminants present in the contaminated stream; utilizing foam fractionation-based separation and concentration of PFAS compounds; resultant from utilizing foam fractionation-based separation, producing a first stream comprising concentrated PFAS compounds and a second stream comprising purified water; destroying the concentrated PFAS compounds in the first stream.
Clause 54. The method any foregoing clause, where the oxidation of non-PFAS contaminants in the introduced contaminated stream includes use of ultraviolet (UV) radiation, ozone, hydrogen peroxide, sodium persulfate, phosphoric acid, or a combination thereof.
Clause 55. The method any foregoing clause, where the ultraviolet (UV) radiation used in the oxidation process is in the range of 15 nm to 220 nm.
Clause 56. The method any foregoing clause, where the UV radiation is combined with use of peroxide, ozone, ammonium, sodium persulfate, or combinations thereof.
Clause 57. The method any foregoing clause further including using a recycle stream to dilute the contaminated source, thereby preventing a build-up of oxidizable contaminants.
Clause 58. The method any foregoing clause, where the introduced contaminated stream is diluted to a level suitable for measuring incoming total organic carbon (TOC).
Clause 59. The method any foregoing clause, where the foam fractionation-based separation utilizes co-surfactants to enhance PFAS concentration and suppress concentration of inorganic materials.
Clause 60. The method any foregoing clause, where the foam fractionation-based separation produces a first stream that is a highly concentrated PFAS stream or foam, and a second stream that is a disposable water stream free of PFAS compounds.
Clause 61. The method any foregoing clause, where the destruction of the concentrated PFAS compounds in the first stream is carried out by supercritical water oxidation.
Clause 62. The method any foregoing clause, where the destruction of the concentrated PFAS compounds in the first stream is carried out by high temperature, low pressure, mineralization using metal oxides with enhanced reactivity.
Clause 63. A method for removing total organic carbon (TOC) prior to supercritical water oxidation of a contaminated stream, the method including introducing a contaminated stream including PFAS contaminants and non-PFAS contaminants, where the non-PFAS contaminants include TOC; diluting the introduced stream to a level suitable for measuring the TOC; applying an applied amount of UV radiation to reduce a content of the TOC; oxidizing the non-PFAS contaminants, leaving most of the PFAS compounds in the contaminated stream.
Clause 64. The method of any foregoing clause further comprising separating and concentrating the remaining PFAS compounds using foam fractionation.
Clause 65. The method of any foregoing clause further comprising destroying the concentrated PFAS compounds using supercritical water oxidation.
Clause 66. The method of any foregoing clause, where the UV emits approximately 185 nm.
Clause 67. The method of any foregoing clause, where the UV emits in a range between approximately 15 nm and approximately 220 nm.
Clause 68. The method of any foregoing clause, where the UV is introduced in the presence of an oxidant.
Clause 69. The method of any foregoing clause, where the oxidant is peroxide.
Clause 70. The method of any foregoing clause, where the oxidant is ozone.
Clause 71. The method of any foregoing clause further comprising utilizing a recycle stream to dilute the feed, thereby preventing a build-up of oxidizable contaminants in the recycle loop.
Clause 72. A system for the destruction of PFAS compounds through mineralization with reactive oxides, the system including an acquisition unit for obtaining reactive oxides; a mixing unit operatively connected to the acquisition unit, where the mixing unit is configured to combine PFAS-contaminated waste with the reactive oxides; a high-temperature treatment unit operatively connected to the mixing unit, where the high-temperature treatment unit is configured to subject the mixture of PFAS-contaminated waste and reactive oxides to a chemical reaction; a cooling unit operatively connected to the high-temperature treatment unit, where the cooling unit is configured to cool the mixture post high-temperature treatment to create a cooled mixture; a waste collection receptacle connected to the cooling unit, where the cooled mixture is directed for disposal; and one or more particulate vapor treatment systems connected to the high-temperature treatment unit and the cooling unit, where PFAS-contaminated atmospheres from the high-temperature treatment unit and the cooling unit are captured to prevent emissions to the environment.
Clause 73. The system of any foregoing clause, where the reactive oxides comprise metal oxides.
Clause 74. The system of any foregoing clause, where the reactive oxides or hydroxides are selected from the group consisting of CaO, MgO, Ca(OH)2, Mg(OH)2, or a mixture thereof.
Clause 75. The system of any foregoing clause, where the acquisition unit operates at a first temperature in a range between approximately 300° C. and approximately 800° C.
Clause 76. The system of any foregoing clause, where the PFAS-contaminated waste is selected from the group consisting of concentrated foam from a foam fractionation system, AFFF, soil, water from washing soil, plastic containers contaminated with PFAS, or combinations thereof.
Clause 77. The system of any foregoing clause, where the mixing is performed using equipment selected from the group consisting of conventional mixers, rotary kilns, calciners, fluidized beds, or a combination thereof.
Clause 78. The system of any foregoing clause, where the high-temperature treatment unit operates at a second temperature between approximately 400° C. and approximately 650° C.
Clause 79. The system of any foregoing clause, where the high-temperature treatment unit comprises furnaces, belt furnaces, rotary kilns, fluidized beds, or combinations thereof.
Clause 80. The system of any foregoing clause, where the cooling unit and the high-temperature treatment unit are a single unit.
Clause 81. The system of any foregoing clause, where the cooling unit and the high-temperature treatment unit are two separate units.
Clause 82. The system of any foregoing clause, where the PFAS-contaminated waste comprises solid waste.
Clause 83. The system of any foregoing clause, where the PFAS-contaminated waste comprises PFAS-contaminated containers.
Clause 84. The system of any foregoing clause further including a shredding unit configured to reduce the PFAS-contaminated waste into smaller pieces, facilitating the mixing with reactive oxides.
Clause 85. The system of any foregoing clause, where the PFAS-contaminated containers are plastic containers used to store AFFF.
Clause 86. The system of any foregoing clause, where the shredding unit is connected to a closed storage system designed to contain the shredded pieces and minimize the hazards associated with plastic dust and PFAS emissions.
Clause 87. The system of any foregoing clause, where the shredded pieces of PFAS-contaminated waste stored in the closed storage system are transported to the mixing unit for combination with the reactive oxides.
Clause 88. The system of any foregoing clause, where the high-temperature treatment unit operates at atmospheric pressure.
Clause 89. The system of any foregoing clause, where the treatment of PFAS-contaminated waste in the high-temperature treatment unit results in the decomposition of the waste, distinct from incineration.
Clause 90. The system of any foregoing clause, where the reactive oxides used in the acquisition unit are metal oxides obtained through thermal decomposition of metal hydroxides selected from the group consisting of Ca(OH)2, Mg(OH)2, or a mixture thereof.
Clause 91. The system of any foregoing clause, where the metal hydroxides are decomposed at a decomposition temperature in a range between approximately 300° C. and approximately 800° C.
Clause 92. A method for treating highly contaminated soil using a PFAS mineralization system, the method including obtaining a quantity of highly contaminated soil, where the highly contaminated soil comprises PFAS compounds; mixing the obtained soil with reactants selected from the group consisting of oxides, hydroxides, or a combination thereof, placing the mixture into a high-temperature treatment unit to allow for chemical decomposition of the PFAS compounds, where the placing the mixture into a high-temperature treatment unit results in a treated mixture; cooling the treated mixture to create a cooled mixture; and disposing of the cooled mixture.
Clause 93. The method of any foregoing clause, where the high-temperature treatment unit is a batch oven, kiln, fluidized bed, or combination thereof.
Clause 94. The method of any foregoing clause, where the high-temperature treatment unit is configured to optimize the chemical decomposition of the PFAS in the soil.
Clause 95. The method of any foregoing clause, where the mixing of the highly contaminated soil with reactants is performed thoroughly to ensure uniform reaction during high-temperature treatment.
Clause 96. The method of any foregoing clause, where the disposing further comprises measures to ensure safe disposal in accordance with environmental regulations.
Clause 97. The method of any foregoing clause, where the mixture is allowed to cool to a predetermined temperature before disposal.
Clause 98. The method of any foregoing clause, where the reactants used for mixing with the highly contaminated soil are pre-determined based on the level of contamination in the soil.
Clause 99. The method of any foregoing clause, where the high-temperature treatment is configured to specifically target the decomposition of PFAS compounds present in the soil.
Clause 100. The method of any foregoing clause further including a step of monitoring the temperature during the high-temperature treatment to ensure optimal decomposition of PFAS.
Clause 101. A system for treating PFAS-contaminated soil, comprising a foam fractionation unit for separating PFAS from contaminated soil water mixture, resulting in a PFAS-enriched foam and clean water; and a mineralization unit for treating the PFAS-enriched foam to destroy PFAS using reactive oxide mineralization processes, wherein the clean water generated from the foam fractionation unit is reused for further washing of PFAS-contaminated soil.
Clause 102. The system of any foregoing clause, wherein the foam fractionation unit utilizes surfactants to enhance the separation of PFAS into the foam.
Clause 103. The system of any foregoing clause, further comprising a soil agitation mechanism to facilitate the release of PFAS into the washing water.
Clause 104. The system of any foregoing clause, wherein the mineralization unit includes a catalyst to accelerate the destruction of PFAS.
Clause 105. The system of any foregoing clause, wherein the foam fractionation unit is capable of operating under variable pressure conditions to optimize PFAS capture.
Clause 106. The system of any foregoing clause, wherein the mineralization unit operates at elevated temperatures to enhance PFAS destruction.
Clause 107. The system of any foregoing clause, further comprising a monitoring system for detecting PFAS concentration levels in the clean water and foam.
Clause 108. The system of any foregoing clause, wherein the foam fractionation and mineralization units are modular and can be scaled according to the extent of soil contamination.
Clause 109. The system of any foregoing clause, where the clean water undergoes filtration to remove any residual particulates before being reused.
Clause 110. The system of any foregoing clause, including a waste handling system for the byproducts of the PFAS destruction process.
Clause 111. The system of any foregoing clause, wherein the foam fractionation unit includes a feedback loop to adjust operational parameters based on the quality of the output water and foam.
Clause 112. The system of any foregoing clause, equipped with a control system using artificial intelligence to optimize the process parameters based on real-time data.
Clause 113. The system of any foregoing clause, including an energy recovery system to utilize heat generated during the mineralization process.
Clause 114. A method for remediating PFAS-contaminated soil, comprising the steps of: (a) washing the PFAS-contaminated soil with water to dissolve PFAS into the water; (b) pumping the PFAS-containing water into a foam fractionation unit to separate PFAS from the water, producing clean water and PFAS-enriched foam; (c) reusing the clean water to wash additional PFAS-contaminated soil; and (d) processing the PFAS-enriched foam through a mineralization unit to destroy the PFAS.
Clause 115. The method of any foregoing clause, wherein the step of washing PFAS-contaminated soil includes adding surfactants to the water to improve PFAS dissolution.
Clause 116. The method of any foregoing clause, further comprising the step of agitating the PFAS-contaminated soil to enhance PFAS release into the water.
Clause 117. The method of any foregoing clause, wherein the mineralization process is catalyzed by adding specific catalysts to the mineralization unit.
Clause 118. The method of any foregoing clause, wherein the clean water is treated with UV light before being reused for soil washing.
Clause 119. The method of any foregoing clause, wherein the PFAS-enriched foam is subjected to multiple cycles of mineralization to ensure complete PFAS destruction.
Clause 120. The method of any foregoing clause, including the use of reactive oxides selected from the group consisting of magnesium oxide, zinc oxide, and titanium dioxide in the mineralization process.
Clause 121. The method of any foregoing clause, where the washing water's pH is adjusted to optimize PFAS dissolution.
Clause 122. The method of any foregoing clause, wherein the mineralization unit uses a combination of reactive oxides to target different PFAS compounds.
Clause 123. A method for the destruction of perfluoroalkyl or polyfluoroalkyl substances (PFAS) in flue gases of high-temperature waste treatment systems, comprising: injecting one or more basic oxides and/or hydroxides into the flue gas at one or more stages of the incineration process to facilitate decomposition of PFAS compounds.
Clause 124. The method of any foregoing clause, wherein the basic oxides and/or hydroxides are selected from the group consisting of CaO, Ca(OH)2, MgO, and Mg(OH)2.
Clause 125. The method of any foregoing clause, wherein the injection takes place into the air intake of the incinerator.
Clause 126. The method of any foregoing clause, wherein the injection takes place directly into the flame within the incinerator.
Clause 127. The method of any foregoing clause, wherein the injection takes place into the hot exhaust post-incineration.
Clause 128. The method of any foregoing clause, further including the step of adjusting the quantity of basic oxides and/or hydroxides injected based on the concentration of PFAS in the flue gas.
Clause 129. The method of any foregoing clause, wherein the basic oxides and/or hydroxides are injected as dry powders.
Clause 130. The method of any foregoing clause, further including a preliminary step of analyzing the flue gas composition to identify predominant PFAS compounds.
Clause 131. The method of any foregoing clause, further including a step of post-treatment analysis to assess the effectiveness of PFAS decomposition.
Clause 132. The method of any foregoing clause, wherein the injection is performed continuously during incineration operations.
Clause 133. A PFAS destruction system for high temperature waste treatment systems, comprising: an injection means for introducing basic oxides and/or hydroxides into the flue gas at one or more points in the incineration process; and a control unit configured to regulate the amount and timing of the injection based on flue gas characteristics.
Clause 134. The system of any foregoing clause, further comprising a separator configured to remove powder from the treated flue gas before release into the environment, where the separator is a cyclone, an electrostatic precipitator, or a bag filter.
Clause 135. The system of any foregoing clause, where the separator is equipped with a cleaning mechanism to prevent clogging by the injected materials.
Clause 136. The system of any foregoing clause, further comprising a monitoring unit for real-time detection of PFAS compounds in the flue gas.
Clause 137. The system of any foregoing clause, wherein the injection means includes a plurality of nozzles positioned at strategic locations within the incineration system.
Clause 138. The system of any foregoing clause, further comprising feedback control loops that adjust the injection based on measured flue gas composition.
Clause 139. The system of any foregoing clause, further comprising a data storage unit for recording injection parameters and flue gas composition for analysis and optimization.
Clause 140. The system of any foregoing clause, where the separator is equipped with a cleaning mechanism to prevent clogging by the injected materials.
Clause 141. The system of any foregoing clause, where the control unit is programmed with algorithms to optimize injection timing and quantity based on historical data.
Clause 142. A dry scrubbing method for reducing PFAS compounds in the flue gas of incineration systems, comprising: identifying stages in the incineration process where PFAS concentrations in flue gas are elevated; and injecting a predetermined quantity of basic oxides and/or hydroxides into the flue gas at the identified stages to decompose PFAS compounds.
Clause 143. The method of any foregoing clause, where the injection of basic oxides and/or hydroxides additionally facilitates the capture of sulfur oxides and other acid gases.
Clause 144. The method of any foregoing clause, further including the step of modifying injection points based on flue gas flow dynamics to optimize PFAS decomposition.
Clause 145. The method of any foregoing clause, wherein the basic oxides and/or hydroxides are pre-treated or activated to enhance their reactivity with PFAS compounds.
Clause 146. A system for mineralizing per- and polyfluoroalkyl substances (PFAS) present in solid waste containers, comprising: a shredder for reducing PFAS-contaminated containers into small pieces; a mixing unit for combining the shredded pieces with reactive oxides; a treatment chamber for exposing the mixture to high temperature conditions sufficient to decompose PFAS compounds.
This application claims priority to U.S. Appl. Ser. No. 63/587,092, filed Sep. 30, 2023, entitled “Systems and Methods for AFFF Destruction,” which patent application is commonly owned by the owner of the present invention. This application claims priority to U.S. Appl. Ser. No. 63/587,102, filed Sep. 30, 2023, entitled “Methods And Systems For PFAS Destruction And Mineralization,” which patent application is commonly owned by the owner of the present invention. This application is a continuation-in-part application and claims priority to U.S. patent application Ser. No. 18/642,499, filed Apr. 22, 2024, entitled “Systems and Methods for Utilizing Foam Fractionation to Separate and Eliminate PFAS,” which claims priority to U.S. Patent Appl. Ser. No. 63/470,631, filed Jun. 2, 2023, entitled “Systems and Methods for Utilizing Foam Fractionation to Separate and Eliminate PFAS,” and U.S. Patent Appl. Ser. No. 63/587,097, filed Sep. 30, 2023, entitled “Systems and Methods for Flexible Foam Fractionation,” and U.S. Patent Appl. Ser. No. 63/587,095, filed Sep. 30, 2023, entitled “Systems and Methods for Foam Draining Using Angled Foam Fractionation Columns,” which patent applications are commonly owned by the owner of the present invention. These patent applications are incorporated herein in their entirety.
| Number | Date | Country | |
|---|---|---|---|
| 63587092 | Sep 2023 | US | |
| 63587102 | Sep 2023 | US | |
| 63470631 | Jun 2023 | US | |
| 63587097 | Sep 2023 | US | |
| 63587095 | Sep 2023 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 18642499 | Apr 2024 | US |
| Child | 18680812 | US |
