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 .
Election/Restrictions
Applicant’s election without traverse of Group I, claims 1-8, in the reply filed on July 15, 2026 is acknowledged.
Claims 9-10 withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on July 15, 2026.
Priority
Acknowledgment is made of applicant’s claim for foreign priority (CN202310374819.3, filed on April 10, 2023) under 35 U.S.C. 119 (a)-(d). Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Objections
Claim 1 objected to because of the following informalities:
In Step (a), the phrase “adding a calcium-magnesium precipitant to the ROC[[,]] and mixing[[,]] to remove hardness” should be corrected to read “adding a calcium-magnesium precipitant to the ROC and mixing the resulting mixture to remove hardness” for proper grammar.
In Step (b), the phrase “filtering a resulting mixture after hardness” should be corrected to read “filtering a resulting mixture after hardness removal” for proper wording.
In Step (b), the phrase “which is realized by forming a filter membrane” should be corrected to read “wherein the filtering is realized by forming a filter membrane” to clarify the grammatical antecedent.
In Step (b), the phrase “organic matter” should be corrected to read “organic matter” for proper grammar.
Claim 2 objected to because of the following informalities:
The phrase “[[a]] precipitation is conducted for 20 min to 50 min” should be corrected to read “precipitation is conducted for 20 min to 50 min” for proper grammar.
Claim 3 objected to because of the following informalities:
The phrase “after continuously cycling for 5 min to 10 min” should be corrected to read “after continuous circulation for 5 min to 10 min” for clarity and consistency.
The phrase “the ROC after hardness” should be corrected to read “the ROC after hardness removal” for proper wording.
The phrase “is introduced by switching a valve to continuously intercept the precipitate” should be corrected to read “is introduced by switching a valve, and the precipitate is continuously intercepted” for proper grammar.
Claim 4 objected to because of the following informalities:
The phrase “the acid and the alkali regenerated from the resource treatment of the ROC” should be corrected to read “the acid and the alkali generated from the resource treatment of the ROC” for consistency.
Claim 8 objected to because of the following informalities:
The phrase “ ROC circulating water, electrode liquid circulating water, acid liquid circulating water, and alkali liquid circulating water” should be corrected to read “ROC circulating water, electrode liquid circulating water, acid liquid circulating water, and alkali liquid circulating water” for proper mass-noun grammar.
The phrase “to not more than 3.0 bar separately” should be corrected to read “to not more than 3.0 bar individually” for proper wording.
Appropriate correction is required.
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 text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
Determining the scope and contents of the prior art.
Ascertaining the differences between the prior art and the claims at issue.
Resolving the level of ordinary skill in the pertinent art.
Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1-8 are rejected under 35 U.S.C. 103 as being unpatentable over LIU et al. (CN101928088A, hereinafter LIU) in view of REN et al. (CN203108308U, hereinafter REN) and ZHANG et al. (CN114149106A, hereinafter ZHANG) and YI et al. (CN103341322A, hereinafter YI).
Regarding Claim 1, LIU discloses a method for the deep treatment and reuse of industrial wastewater, specifically reverse osmosis concentrate (ROC) from petrochemical enterprises (¶[0002]).
Reference to FIG. 1, the treatment method is applied to reverse osmosis concentrate (ROC) having high total hardness and COD, and the process includes adding NaOH to the nanofiltration concentrate to remove magnesium hardness, followed by adding Na₂CO₃, precipitation, and solid-liquid separation to remove calcium hardness. The concentrate after magnesium and calcium hardness removal is subjected to microfiltration, and hydrochloric acid is added to the microfiltration permeate to adjust the pH before further reverse osmosis treatment (¶¶[0012], [0014]–[0016]).
Based on the disclosure, it is reasonable to interpret that the amount of hydrochloric acid added to the microfiltration permeate would be adjusted according to the pH required for the subsequent treatment process. Accordingly, when the subsequent treatment is performed under acidic conditions, a person skilled in the art would optimize the amount of hydrochloric acid to adjust the resulting filtrate to be acidic. The foregoing disclosures fully correspond to steps (a) and (c) and partially correspond to step (b).
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FIG. 1 of LIU (Translated)
However, LIU does not explicitly disclose using a diatomaceous earth filter for the microfiltration treatment.
REN discloses a diatomaceous earth filtration water treatment device (¶[0002]). The filtration device circulates water through a filter column containing filter elements coated with a diatomaceous earth film. Diatomaceous earth slurry is pumped into the filter column to form a uniform coating on the filter elements, and the water is filtered through the coating before being discharged from the filter column (¶¶[0012]–[0013]).
The diatomaceous earth filter disclosed by REN improves the removal of algae and small-molecule organic matter while providing higher filtration efficiency and accuracy through a smaller system that reduces secondary pollution, head loss, energy consumption, and water use without requiring flocculants (¶¶[0005]–[0006]). In view of LIU’s generic microfiltration of the concentrate, a person skilled in the art would incorporate the diatomaceous earth filter into the treatment to predictably improve the removal of small-molecule organic matter and increase filtration efficiency and accuracy.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the diatomaceous earth filter, as disclosed by REN, into the microfiltration treatment step of the wastewater treatment method by LIU.
However, modified LIU does not explicitly disclose electro-Fenton treatment followed by bipolar membrane electrodialysis for generating acid and alkali.
ZHANG discloses a method for treating high-salinity organic wastewater (¶[0001]). In Example 2, with reference to FIG. 1, electrochemical catalytic oxidation and iron-carbon microelectrode treatment reduce the COD by 90% when the initial COD is 6000 mg/L, or by 92% when the initial COD is 7000 mg/L. The wastewater then enters an electro-Fenton unit, after which the COD is reduced to 5 mg/L. The resulting concentrate enters a bipolar membrane electrodialysis acid-base regeneration system, which produces acid and alkali (¶¶[n0032]–[n0034]).
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FIG. 1 of ZHANG (Translated)
Based on the disclosed values, the electrochemical catalytic oxidation and iron-carbon microelectrode treatment leaves 600 mg/L or 560 mg/L COD in the wastewater entering the electro-Fenton unit. Reducing those COD concentrations to 5 mg/L corresponds to COD removal rates of approximately 99.2% and 99.1%, respectively, which fall within the recited “not less than 97%” COD removal rate.
The electro-Fenton treatment and bipolar membrane electrodialysis disclosed by ZHANG provide strong oxidation and high treatment efficiency for high-salinity wastewater while producing corresponding acids and alkalis during desalination to achieve wastewater treatment and resource recovery with reduced equipment investment, energy consumption, and secondary pollution (¶[n0006]). In view of modified LIU’s treatment process, a person skilled in the art would incorporate the electro-Fenton treatment followed by bipolar membrane electrodialysis into the treatment process to predictably reduce COD through strong oxidation while generating acid and alkali during desalination for resource recovery.
Regarding the limitation “feeding a resulting acidic filtrate into an electro-Fenton process,” adjusting the pH of the resulting filtrate is considered an optimization of a known process condition. Electro-Fenton treatment relies on dissolved Fe²⁺/Fe³⁺ cycling to activate H₂O₂ and generate hydroxyl radicals. Under acidic conditions, iron remains soluble and available for the reaction, whereas increasing the pH promotes hydrolysis and precipitation of Fe³⁺ as Fe(OH)₃, reducing hydroxyl-radical generation and oxidation efficiency. A person skilled in the art would therefore optimize the pH of the resulting filtrate to be acidic before electro-Fenton treatment to predictably maintain soluble iron species and effective hydroxyl-radical generation for COD removal. The foregoing disclosures fully correspond to steps (d) and (f).
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the electro-Fenton treatment followed by bipolar membrane electrodialysis, as disclosed by ZHANG, into the wastewater treatment method by modified LIU.
However, modified LIU does not explicitly disclose a polypropylene microporous filter before bipolar membrane electrodialysis.
YI discloses a pretreatment method for producing acid and alkali from sodium sulfate waste liquid of viscose fiber by bipolar membrane electrodialysis (¶[0002]). In the pretreatment process, the sodium sulfate solution exiting the ion exchange resin system is further filtered through a polypropylene microporous filter to obtain a treatment solution suitable for entering the bipolar membrane electrodialysis module (¶[0051]). The polypropylene filter removes smaller particles from the sodium sulfate solution, and the treated liquid then enters the sodium sulfate channel of the bipolar membrane electrodialysis unit while demineralized water enters the acid and alkali channels, respectively (¶¶[0056]–[0057]). The treated solution undergoes bipolar membrane electrodialysis to obtain a sulfuric acid solution having a concentration of 1 g/L and a sodium hydroxide solution having a concentration of 5 g/L (¶[0061]).
The polypropylene microporous filter in the pretreatment disclosed by YI prevents flow-channel blockage and increased membrane resistance while improving acid and alkali regeneration and recovery, extending membrane life, and ensuring smooth operation of the bipolar membrane electrodialysis unit (¶¶[0011], [0014]). In view of modified LIU’s feeding of the electro-Fenton effluent into bipolar membrane electrodialysis in the wastewater treatment method, a person skilled in the art would incorporate a polypropylene microporous filter to predictably remove smaller particles from the electro-Fenton effluent, prevent flow-channel blockage and increased membrane resistance, and improve acid and alkali regeneration and recovery.
Therefore, it would have been obvious to a person having ordinary skill in the art, prior to the effective filing date of the claimed invention, to incorporate the polypropylene microporous filter, as disclosed by YI, between the electro-Fenton treatment and bipolar membrane electrodialysis of the wastewater treatment method by modified LIU.
Regarding Claim 2, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 1. LIU discloses adding NaOH to remove magnesium hardness, followed by adding Na₂CO₃, precipitation, and solid-liquid separation to remove calcium hardness. The resulting concentrate has a pH of 9.0–11.5 (¶¶[0014]–[0015]), which overlaps the claimed "pH value of 11 to 12."
Regarding the claimed weight percentages of NaOH and Na₂CO₃ and the precipitation time, these parameters are considered result-effective variables. LIU uses NaOH and Na₂CO₃ to precipitate magnesium and calcium hardness and obtains a resulting concentrate having a pH of 9.0–11.5, which overlaps the claimed pH range. Although LIU does not expressly disclose the claimed weight percentages and precipitation time, these parameters affect the resulting pH and the extent of precipitation. A person skilled in the art would therefore optimize the respective weight percentages of NaOH and Na₂CO₃ and the precipitation time through routine experimentation to select values that produce LIU’s already-disclosed overlapping pH and effective hardness removal (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 3, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 1. QIU discloses adding diatomaceous earth at 0.5 g/L to 1.0 g/L and pumping the resulting slurry into a diatomaceous earth filter column to pre-coat a filter element. The pre-coating cycle is conducted for 5 min to 10 min until a uniform diatomaceous earth coating is formed on the filter element. After pre-coating, the valves are switched to the filtration loop, where suspended impurities and organic matter are intercepted by the diatomaceous earth coating (¶[0031]). The disclosed amount of 0.5 g/L to 1.0 g/L overlaps the claimed “0.8 g/L to 1.0 g/L.”
Furthermore, based on the disclosure, it is reasonable to apply the known filtration process disclosed by QIU to LIU’s ROC after hardness removal, such that the ROC is introduced by switching the valves and the precipitate is continuously intercepted by the formed diatomaceous earth coating.
Regarding the claimed particle size of 6 μm to 25 μm, the particle size of the diatomaceous earth is considered a result-effective variable. The particle size affects the packing and pore structure of the formed coating, which affects filtration accuracy and flow resistance. A person skilled in the art would optimize the particle size through routine experimentation to obtain a diatomaceous earth coating having suitable filtration accuracy and flow characteristics (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 4, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 1. LIU discloses adding hydrochloric acid to the microfiltration permeate to adjust its pH before subsequent treatment (¶[0016]). ZHANG discloses that bipolar membrane electrodialysis produces hydrochloric acid, sulfuric acid, and sodium hydroxide during desalination of high-salinity wastewater. The generated acids and alkalis can be reused for cleaning equipment and membranes or further concentrated for resource utilization (¶[n0006]).
Regarding the claimed residence time of 10 min to 20 min and pH of 2 to 4, these parameters are considered result-effective variables. It is well known that electro-Fenton treatment operates optimally at a pH of about 2.8 to 3.0, which falls within the claimed range. The residence time affects the time available for the hydrochloric acid to mix with the microfiltration permeate and stabilize the resulting filtrate at the selected pH. In view of LIU’s pH-adjustment stage and ZHANG’s regeneration of acid and alkali by bipolar membrane electrodialysis, a person skilled in the art would reuse the regenerated acid as the pH adjuster in LIU’s process and optimize the residence time through routine experimentation to obtain the desired pH range (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 5, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 1. ZHANG discloses electro-Fenton treatment using an iron anode and a graphite cathode at a current density of 20 A/m² to 60 A/m² for a reaction time of 60 min to 120 min (¶[n0013]), which overlaps the claimed “20 min to 100 min.”
Regarding the claimed pH value of 2.5 to 3.5, as previously discussed, the well-known optimal pH range for electro-Fenton treatment is about 2.8 to 3.0, which falls within the claimed range.
Regarding the claimed voltage of 10 V to 30 V, the applied voltage is considered a result-effective variable. The applied voltage affects the resulting current density in the electro-Fenton cell and, consequently, the generation of hydroxyl radicals for oxidation. In view of ZHANG’s current-controlled electro-Fenton treatment at a current density of 20 A/m² to 60 A/m², a person skilled in the art would optimize the applied voltage through routine experimentation to provide and maintain the disclosed current density and effective oxidation (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 6, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 1. YI discloses PP microporous filtration in which the microporous filter membrane has a pore size of 0.22 μm to 1 μm (¶[0028]), which overlaps the claimed “0.2 μm to 1.0 μm.”
Regarding Claim 7, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 1. ZHANG discloses a bipolar membrane electrodialysis system comprising three membrane stacks connected in series, each including a cation exchange membrane, an anion exchange membrane, and a bipolar membrane. The inlet flow rates of the acid, alkali, and salt chambers are 3 m³/h to 4 m³/h, and the system operates at a direct-current voltage of 90 V to 120 V (¶[n0014]).
Regarding the claimed flow rate of 60 L/h to 240 L/h and direct-current voltage of 1 V to 3 V applied to each group of membranes, these parameters are considered result-effective variables. ZHANG demonstrates bipolar membrane electrodialysis operated under controlled flow and voltage conditions to produce acid and alkali from wastewater following electro-Fenton treatment achieving greater than 99% COD removal. The flow rate affects residence time and ion transport within the acid, alkali, and salt chambers, while the voltage applied to each group of membranes affects the electric field driving water dissociation and ion migration. The appropriate flow rate and voltage depend on the membrane area, number of membrane groups, number of membrane stacks, and treatment capacity. A person skilled in the art would therefore optimize the flow rate and voltage applied to each group of membranes through routine experimentation to obtain effective desalination and acid and alkali production for the selected system scale and configuration (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding Claim 8, modified LIU makes obvious the reverse osmosis concentrated brine treatment method of Claim 7.
LIU discloses treating ROC having a pH of 7.0 to 10.0, a conductivity of 3000 μS/cm to 7000 μS/cm, a total hardness of 1000 mg/L to 3000 mg/L, and a COD of 20 mg/L to 200 mg/L (¶[0012]).
ZHANG discloses high-salinity wastewater containing sodium, calcium, chloride, and sulfate ions, which provide favorable conditions for electrochemical treatment (¶[n0004]). Bipolar membrane electrodialysis converts the salts into hydrochloric acid, sulfuric acid, and sodium hydroxide, and the generated acids and alkalis can be reused or concentrated for resource utilization (¶[n0006]).
The bipolar membrane acid-base regeneration system includes three membrane stacks connected in series, each including a cation exchange membrane, an anion exchange membrane, and a bipolar membrane. The acid, alkali, and salt chambers have inlet pressures of 1.0 MPa to 1.2 MPa, outlet pressures of 0.4 MPa to 0.8 MPa, and inlet flow rates of 3 m³/h to 4 m³/h. The electrode chamber has an inlet pressure of 0.8 MPa to 1.0 MPa, an outlet pressure of 0.5 MPa to 0.8 MPa, and an inlet flow rate of 6 m³/h to 8 m³/h. The system operates using direct current at a voltage of 90 V to 120 V (¶[n0014]).
During operation, the flow rates and pressures of the acid, alkali, salt, and electrode chambers are stabilized before power is turned on. The initial acid concentration is 0.03 mol/L to 0.05 mol/L HCl, the initial alkali concentration is 0.03 mol/L to 0.05 mol/L NaOH, and the electrode chamber concentration is 0.2 mol/L to 0.4 mol/L Na₂SO₄. The flow ratio of the acid, alkali, and salt streams is 1:1:1, and the electrode-water flow rate is the sum of the acid and alkali flow rates. The system operates at a constant current with a membrane current density of 30 mA/cm² to 60 mA/cm², while the pressure difference across the system is maintained within 0.2 MPa (¶[n0015]).
Regarding the claimed use of sulfuric acid as the initial acid liquid, ZHANG uses HCl as the initial acid liquid but also discloses sulfate-containing wastewater and the production of sulfuric acid by bipolar membrane electrodialysis. HCl and H₂SO₄ are known mineral acids suitable for providing an acidic and electrically conductive solution in the acid chamber. A person skilled in the art would therefore select H₂SO₄ as the initial acid liquid when treating sulfate-containing wastewater and producing sulfuric acid, with predictable results.
Regarding the claimed initial mass concentrations of 3.5% to 20% ROC, 1% to 3% Na₂SO₄ electrode liquid, 1% to 5% acid liquid, and 1% to 5% NaOH alkali liquid, these concentrations are considered result-effective variables. ZHANG operates the bipolar membrane electrodialysis system using high-salinity wastewater and initial Na₂SO₄, acid, and NaOH solutions. The concentrations affect conductivity and ion transport within the respective liquids. A person skilled in the art would optimize the concentrations through routine experimentation to obtain stable electrical operation and effective acid and alkali production (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding the claimed constant-voltage operation and current limit of 10 A to 15 A, the voltage and current limit are considered result-effective variables. ZHANG discloses controlled direct-current operation at a specified membrane current density. The voltage and current limit affect the resulting current density and ion migration through the membranes. A person skilled in the art would optimize these parameters through routine experimentation to obtain effective ion transport and acid and alkali production for the selected membrane-stack configuration (In re Aller, 220 F.2d 454, 456–57; 1955).
Regarding the claimed balanced circulation pressures not exceeding 3.0 bar, ZHANG discloses circulating the liquids under controlled flow and pressure conditions. The limitation merely sets an upper limit on the water-flow pressure generated during circulation and does not require a separate high-pressure treatment step. The circulation pressure depends on ordinary hydraulic operating conditions, including pump output, valve position, flow rate, and membrane-stack resistance. A person skilled in the art would adjust these conditions to maintain balanced circulation at a pressure not exceeding 3.0 bar, with predictable results.
Regarding the claimed circulation time of 10 min to 20 min, the circulation time is considered a result-effective variable. ZHANG stabilizes the flow rates and pressures before energizing the system. The circulation time affects flow stabilization and removal of air from the membrane stack. A person skilled in the art would optimize the circulation time through routine experimentation to obtain stable circulation before electrical operation (In re Aller, 220 F.2d 454, 456–57; 1955).Top of Form
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TAK L. CHIU whose telephone number is (703)756-1059. The examiner can normally be reached M-F: 9:00am - 6:00pm (CST).
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/TAK L. CHIU/Examiner, Art Unit 1771
/PREM C SINGH/Supervisory Patent Examiner, Art Unit 1771
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