Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Response to Arguments
Applicant's arguments filed December 2nd, 2025 have been fully considered but they are not persuasive.
Applicant argues that Cunningham (US10493427B2) cannot serve as a primary reference because it does not expressly mention PFAS and is instead directed to “conventional organics”. This argument is not persuasive. Cunningham discloses a multi-stage powdered activated carbon treatment (PACT) system combined with wet air regeneration (WAR) and downstream separation, configured to remove contaminants from water and to regenerate and recycle carbon solids within the system. Cunningham expressly teaches that the contaminants removed include a wide range of organic contaminants and further makes clear that the disclosed system is a general wastewater treatment architecture, not a chemistry-specific process limited to any particular contaminant species. Obviousness under 35 U.S.C. §103 does not require that a primary reference expressly name the same contaminant as recited in the claims. Rather, it is sufficient that the reference discloses the structural and functional framework of the claimed system, with additional references supplying teachings directed to a particular contaminant of interest. Here, Cunningham provides the foundational treatment train (PACT, WAR, separation, recycle), while Nelson (WO2017218335A1), Duckworth (AU2020289754B2) and Chiang (WO2018097875A1) provide known teachings regarding PFAS concentration and destruction. The Office has not impermissibly substituted PFAS into Cunningham, but has instead relied on the combined teachings of the applied references as a whole, which was within the ability of a person of ordinary skill in the art.
Applicant asserts that the rejection relies on impermissible hindsight because PFAS-specific references are used to modify Cunningham. This argument is not persuasive. As set forth in MPEP §2143, a conclusion of obviousness may be based on a combination of references where each reference contributes a known element or function, and where the combination yields predictable results. The Office’s rejection does not rely on Applicant’s disclosure as a blueprint. Rather, the Office relies on independent prior-art teachings establishing that (i) activated carbon systems are used to remove contaminants from water (Cunningham), (ii) PFAS are known to be adsorbed, concentrated and managed using known physical and chemical processes (Nelson and Duckworth), and (iii) electro-oxidation is a known technique for destruction of PFAS in treated or concentrated streams (Chiang). The rationale for combination arises from the known problem of PFAS persistence in water and the well-established use of modular treatment trains to address emerging contaminants. This represents routine engineering adaptation, not hindsight reconstruction.
Applicant argues that the Office has failed to articulate a convincing motivation to combine the references. The Examiner disagrees. At the time of the invention, PFAS were well-known to be persistent, difficult to degrade contaminants requiring multi-step treatment approaches, often involving adsorption of concentration followed by destruction. Cunningham teaches a system expressly designed to remove contaminants from wastewater while regenerating and recycling activated carbon using WAR and separation processes. Nelson and Duckworth teach methods for concentrating PFAS to improve downstream handling, and Chiang teaches electro-oxidation as a destruction mechanism for PFAS in treated streams. A person of ordinary skill in the art would have been motivated to combine these teachings to adapt an existing, known contaminant-removal architecture (Cunningham) for the treatment of PFAS by incorporating known PFAS-specific concentration and oxidation steps, thereby improving overall PFAS management efficiency. Such motivation arises from the recognized inadequacy of single-step PFAS treatment methods and the known benefits of modular, staged treatment systems.
Applicant further argues that a person of ordinary skill in the art would lack a reasonable expectation of success due to alleged incompatibilities between the systems. This argument is not persuasive. The applied references do not teach that the disclosed systems are incompatible or inoperable when combined. While Applicant identifies differences in operating conditions, energy usage, and contaminant sensitivity, such differences represent design considerations and optimization issues, not technical incompatibilities. A reasonable expectation of success does not require certainty of optimal performance, but only that the combination would be expected to function for its intended purpose. Here, the references collectively teach that contaminants can be adsorbed onto carbon, regenerated, separated, concentrated, and subsequently oxidized. The fact that process parameters may need to be adjusted to accommodate PFAS does not negate the reasonable expectation that the combined system would operate to remove and destroy PFAS.
Applicant contends that Nelson and Duckworth teach away from combination with Cunningham. The Examiner disagrees. Nelson’s discussion of limitations associated with certain remediation approaches does not constitute a teaching away from upstream or downstream treatment integration. Rather, Nelson identifies shortcomings in existing approaches and proposes alternative PFAS concentration techniques, which would naturally motivate integration with additional treatment stages. Similarly, Duckworth’s preference for lower-energy processes does not amount to a teaching away from higher-energy treatment steps, particularly where such steps are applied after concentration or volume reduction. Preferences for efficiency do not arise to the level of discouraging or criticizing the claimed combination.
Applicant argues that Chiang discourages electro-oxidation in the presence of bulk wastewater constituents. However, Chiang teaches electro-oxidation for treated or conditioned streams, which is consistent with the Office’s reliance on separation and concentration steps prior to electro-oxidation. Cunningham itself teaches separation of regenerated carbon solids from waste liquor, thereby providing streams suitable for further treatment. Potential fouling or efficiency concerns would have been recognized by a person of ordinary skill as routine engineering challenges to be addressed through known conditioning, separation, or pretreatment techniques, not as barriers to combination.
Applicants arguments regarding dependent claims rely entirely on the alleged allowability of the independent claims. As the independent claims remain unpatentable for the reasons set forth above, the dependent claims remain unpatentable as well.
For the reasons stated above, Applicant’s arguments have been fully considered but are not persuasive. The applied references, when properly combined, render the claimed subject matter obvious under 35 U.S.C. §103. Accordingly the rejections are maintained.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-3, 5-12 and 15-19 are rejected under 35 U.S.C. 103 as being unpatentable over Cunningham (US10493427B2) in view of Nelson (WO2017218335A1), and further in view of Duckworth (AU2020289754B2), Chiang (WO2018097875A1) and Thoreson (US-20210170363-A1).
Regarding claim 1, Cunningham discloses a water treatment system (Cunningham col. 1 line 56) comprising: a powdered activated carbon treatment (PACT) system comprising an amount of powdered activated carbon therein (Cunningham col. 2 line 64), wherein the PACT system is configured to treat an amount of water comprising a concentration of organic contaminants to remove at least a portion of the organic contaminants (Cunningham col. 3 lines 11-14) from the amount of water and produce a spent carbon material having the organic contaminants adsorbed thereon (Cunningham col. 3 lines 61-64); a wet air regeneration (WAR) system in fluid communication with the PACT system and configured to regenerate the spent carbon material while destroying biological solids (Cunningham col. 4 lines 6-13 and lines 35-37); a separation station in fluid communication with the WAR system to separate an effluent from the WAR system (Cunningham col. 4 line 54) into a regenerated carbon solids fraction (Cunningham col. 4 lines 54-55 “cleaned carbon solids fraction”) and a waste liquor containing the organic contaminants (Cunningham col. 4 line 56).
Cunningham does not disclose the organic contaminant is a concentration of per- and polyfluorinated alkyl substances (PFAS). Cunningham also does not disclose a concentrator in fluid communication with the separation station to concentrate the PFAS in the waste liquor and provide a PFAS concentrate fraction and an effluent stream; and an electro-oxidation unit in fluid communication with the concentrator and configured to oxidize at least a portion of the PFAS in the PFAS concentrate fraction to provide an electro- oxidation effluent stream.
Nelson discloses treating PFAS-contaminated water by foam fractionation to selectively concentrate PFAS into a reduced-volume concentrate stream and produce a treated effluent stream, thereby teaching a concentrator suitable for placement downstream of an existing treatment system (Nelson abstract and p. 1 par. 1). Nelson discloses that the perfluorinated carbon tail and an ionic headgroup that causes PFAS to preferentially accumulate at air-water interfaces and traditional in-situ remediation technologies such as chemical reduction, chemical oxidation, and bioremediation have not been shown to be effective in treating PFAS.
Duckworth discloses an above-ground low-energy foam fractionation process (Duckworth abstract) with multiple vessels to generate progressively concentrated PFAS waste streams and clean water streams (Duckworth p. 13 lines 16-29) followed by solar drying/evaporation for further concentration (Duckworth p. 18 lines 30-31). Duckworth further teaches that PFAS concentration may be performed by these multiple stages to generate progressively enriched PFAS waste streams, confirming that foam fractionation is effective for concentrating PFAS from complex aqueous streams and reinforcing a reasonable expectation of success when applied to waste liquor streams generated by other treatment processes.
Chiang discloses the use of electrochemical oxidation for treatment of per-and polyfluoroalkyl substances in an effluent stream (Chiang abstract and title). Chiang discloses that while electro-oxidation may be used to directly treat these contaminants it is more efficient to pre-concentrate the pollutants (Chiang abstract) into concentrate streams prior to electro-oxidation, thereby expressly motivating placement of an electro-oxidation unit downstream of a concentrator to improve treatment efficiency.
Cunningham is relied upon as it discloses a contaminant-agnostic powdered activated carbon treatment and regeneration architecture configured to remove persistent organic contaminants from water and to generate concentrated waste liquor steams suitable for downstream treatment, regardless of the specific identity of the organic contaminant.
Further, Thoreson teaches that per- and polyfluoroalkyl substances adsorbed to activated carbon may be concentrated and subsequently destroyed using electrochemical processes, and explicitly recognizes powdered activated carbon treatment systems as prior art, thereby reinforcing that a person of ordinary skill in the art would have reasonably expected success in integrating PFAS concentration and electro-oxidation steps with Cunningham’s PACT/WAR system.
It would have been obvious to one of ordinary skill in the art at the time of filing to combine the PACT/WAR/separation system of Cunningham with the PFAS concentration teachings of Nelson and Duckworth and the PFAS electro-oxidation teachings of Chiang to achieve the claimed invention. Cunningham already generates a waste liquor stream from the WAR separation that contains concentrated organic contaminants. Duckworth and Nelson teach that PFAS in such waste streams can be effectively concentrated by foam fractionation to reduce disposal volume while Chiang further teaches that these concentrates are preferable for efficient electro-oxidation destruction.
Combining these references would have been a straightforward substitution and integration of known PFAS treatment steps such as concentration followed by destruction or removal, into Cunningham’s existing wastewater treatment system. Each step is already known to improve overall PFAS management efficiency and would have yielded predicable results. A person of ordinary skill in the art would have been motivated to integrate these teachings to address the well-recognized problem of persistent PFAS contamination using a staged treatment approach, wherein adsorption and regeneration generate a concentrated waste stream, concentration reduces disposal volume, and electro-oxidation provides destruction of the concentrated PFAS. The applied references collectively teach that each step performs its known function in such a treatment train, and their combination would have involved routine system integration.
Regarding claim 2, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 1, wherein the WAR system comprises an outlet fluidly connected to the PACT system to provide the regenerated carbon solids fraction to the PACT system to treat additional water (Cunningham col. 6 lines 4-8).
Regarding claim 3, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 1, further comprising a separator fluidly connected downstream of the PACT system and fluidly connected upstream of the WAR system (Cunningham Fig. 1), wherein the separator provides a clean water stream (Cunningham col. 4 “cleaned carbon solids faction” meaning that a liquid portion comprising byproducts from the effluent is removed from the effluent such that a remaining carbon solids portion includes a reduced amount of the byproducts from the WAR process) and a PFAS-containing slurry (Cunningham col. 4 “waste liquor” would contain remaining PFAS by suggestion of Nelson, Duckworth and Chiang), and wherein the PFAS-containing slurry is directed to the WAR system and the clean water stream is output from the water treatment system (Cunningham Fig. 1 shows plainly that the “water liquor” is directed to the WAR system from stage 1 of the PACT while the clean water stream is conducted from the system as polished water 115).
Regarding claim 5, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 1, wherein the electro-oxidation unit comprises an outlet fluidly connected to the PACT system to provide the electro-oxidation effluent stream to the PACT system for additional treatment by the PACT system (Chiang par. [0011] describes the option of recycling EO effluents into upstream treatment stages).
Regarding claim 6, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 1, wherein the concentrator comprises a foam fractionation unit (Duckworth p. 13 line 16).
Regarding claim 7, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 1, further comprising a precipitation unit configured to recover a nutrient fraction from the PFAS concentrate fraction (Duckworth p. 13 line 17 states the second vessel may be a foam fractionator which moves substances in the liquid to the foamate phase where it can be reclaimed and in p. 8 lines 8-17 describe the additional removal of total nitrogen by means of a second active aeration).
Regarding claim 8, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 7, wherein the precipitation unit is fluidly coupled downstream of the WAR system and upstream of the PACT system (Duckworth precipitation unit is fluidly coupled downstream of WAR system and upstream of the electro-oxidation system of Chiang who suggest in par. [0011] the option of recycling EO effluents into upstream treatment stages).
Regarding claim 9, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose a method for removing per- and polyfluorinated alkyl substances (PFAS) from water, the method comprising: treating an amount of water containing PFAS in a powdered activated carbon (PACT) system (Cunningham col. 2 line 64 where the organic contaminant is PFAS by suggestion of Nelson, Duckworth and Chiang), wherein the treating removes PFAS from the water and produces a spent carbon material having the PFAS adsorbed thereon (Cunningham col. 3 lines 61-64); directing an amount of the spent carbon material having the PFAS adsorbed thereon to a wet air regeneration (WAR) system for regeneration of the spent carbon material and destruction of biological solids (Cunningham col. 4 lines 6-13 and lines 35-37); separating an effluent from the WAR system (Cunningham col. 4 line 54) into a regenerated carbon solids fraction (Cunningham col. 4 lines 54-55 “cleaned carbon solids fraction”) and a waste liquor containing the PFAS (Cunningham col. 4 line 56); directing the waste liquor to a concentrator to concentrate the PFAS (Duckworth p. 13 lines 20-22 “foam fractionator”), wherein the concentrator produces a PFAS concentrate fraction (Duckworth p. 13 line 34-p. 14 line 1 “produces a waste stream comprising a concentration of PFAS) and an effluent stream (Duckworth p. 14 line 1 “first water stream”); providing the PFAS concentrate fraction to an electro-oxidation unit configured to oxidize at least a portion of the PFAS in the PFAS concentrate fraction to provide an electro- oxidation effluent stream (Chiang claim 1); and directing the electro-oxidation effluent stream to the PACT system (Chiang par. [0011] suggests the option of recycling EO effluents into upstream treatment stages).
Regarding claim 10, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 9, further comprising directing the regenerated carbon solids fraction to the PACT system (Cunningham col. 6 lines 4-8).
Regarding claim 11, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 9, further comprising directing the effluent stream from the concentrator to the PACT system (Duckworth foam fractionator provides concentrated effluent stream to the electro-oxidation system of Chiang who suggest in par. [0011] the option of recycling EO effluents into upstream treatment stages by this suggestion directs this effluent back to the PACT system).
Regarding claim 12, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 9, further comprising separating the spent carbon material having the PFAS adsorbed thereon into a clean water stream (Cunningham col. 4 “cleaned carbon solids faction” meaning that a liquid portion comprising byproducts from the effluent is removed from the effluent such that a remaining carbon solids portion includes a reduced amount of the byproducts from the WAR process) and a PFAS-containing slurry (Cunningham col. 4 “waste liquor” would contain remaining PFAS by suggestion of Nelson, Duckworth and Chiang), and wherein the PFAS-containing slurry is directed to the WAR system and the clean water stream is provided as an output (Cunningham Fig. 1 shows plainly that the “water liquor” is directed to the WAR system from stage 1 of the PACT while the clean water stream is conducted from the system as polished water 115).
Regarding claim 15, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 9, further comprising recovering a nutrient fraction from the PFAS concentrate fraction (Cunningham col. 5 lines 14-19 “nitrogen containing contaminants…treat and/or remove”).
Regarding claim 16, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 15, wherein the nutrient fraction is provided prior to concentrating the PFAS from the waste liquor (the separation station of Cunningham where nutrient fraction is provided occurs prior to the concentration step of Duckworth).
Regarding claim 17, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 9, wherein the electro-oxidation effluent stream is combined with an additional amount of water (Chiang par. [0005] “effluent can be diluted”).
Regarding claim 18, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 9, further comprising separating an amount of ash from the regenerated carbon solids fraction or the waste liquor (Cunningham col. 6 line 37).
Regarding claim 19, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose a water treatment system for treating water (Cunningham col. 1 line 56) comprising a concentration of per- and polyfluorinated alkyl substances (PFAS)(By suggestion of Nelson, Duckworth and Chiang) comprising: an amount of powdered activated carbon (Cunningham col. 2 line 64) configured to adsorb at least a portion of the PFAS (Cunningham col. 3 lines 11-14 by suggestion of Nelson, Duckworth and Chiang the organic contaminant is PFAS), thereby forming a spent carbon material having the PFAS adsorbed thereon (Cunningham col. 3 lines 61-64); a wet air regeneration (WAR) system configured to regenerate the spent carbon material (Cunningham col. 4 lines 6-13 and lines 35-37); a separation station in fluid communication with the WAR system (Cunningham col. 4 line 54) to separate an effluent from the WAR system into a regenerated carbon solids fraction (Cunningham col. 4 lines 54-55 “cleaned carbon solids fraction”) and a waste liquor containing the PFAS (Cunningham col. 4 line 56); a concentrator in fluid communication with the separation station (Duckworth p. 13 line 16 “Foam fractionator”) to concentrate the PFAS in the waste liquor and provide a PFAS concentrate fraction (Duckworth p. 13 line 34-p. 14 line 1 “produces a waste stream comprising a concentration of PFAS) and an effluent stream (Duckworth p. 14 line 1 “first water stream”); and an electro-oxidation unit in fluid communication with the concentrator and configured to oxidize at least a portion of the PFAS in the PFAS concentrate fraction (Chiang claim 1) to provide an electro- oxidation effluent stream (Chiang p. 4 line 3 “effluent of this EO process”).
Claims 4 and 13-14 are rejected under 35 U.S.C. 103 as being unpatentable over Cunningham (US10493427B2) in view of Nelson (WO2017218335A1), and further in view of Duckworth (AU2020289754B2), Chiang (WO2018097875A1) and Thoreson (US-20210170363-A1) as applied to claim 3 and 12 above, and further in view of EPA, "PFAS Treatment in Drinking Water and Wastewater-State of the Science".
Regarding claim 4, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the water treatment system of claim 3.
The combination of Cunningham, Nelson, Duckworth, Chiang or Thoreson do not disclose wherein the separator comprises an ultrafiltration (UF) membrane.
However, the EPA, in a review of the “State of the Science” discloses that suitable treatments of PFOS include high pressure membranes, which includes devices such as ultrafiltration, nanofiltration and reverse osmosis (EPA review p. 10).
A person of ordinary skill in the art would have been motivated to combine the teachings of the EPA review’s membrane disclosure to substitute a UF membrane separator, since doing so would predictably reduce suspended solids and provide high-quality effluent prior to concentration or destruction, consistent with the goals of reducing disposal volumes and achieving PFAS compliance.
Regarding claim 13, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 12, wherein the separating comprising using an ultrafiltration (UF) membrane (EPA review p. 10 “high-pressure membranes”).
Regarding claim 14, Cunningham in view of Nelson, Duckworth, Chiang and Thoreson disclose the method of claim 12, wherein the clean water stream is free of PFAS (Cunningham col. 6 line 2 “substantially free of contaminants”).
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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/W.A.G./ Examiner, Art Unit 1779
/Bobby Ramdhanie/ Supervisory Patent Examiner, Art Unit 1779