Prosecution Insights
Last updated: April 19, 2026
Application No. 18/475,317

REMOVING BIVALENT IONS FROM PRODUCED WATER

Non-Final OA §103§112
Filed
Sep 27, 2023
Examiner
PATEL, PRANAV N
Art Unit
1777
Tech Center
1700 — Chemical & Materials Engineering
Assignee
Saudi Arabian Oil Company
OA Round
1 (Non-Final)
68%
Grant Probability
Favorable
1-2
OA Rounds
3y 0m
To Grant
90%
With Interview

Examiner Intelligence

Grants 68% — above average
68%
Career Allow Rate
433 granted / 637 resolved
+3.0% vs TC avg
Strong +22% interview lift
Without
With
+22.2%
Interview Lift
resolved cases with interview
Typical timeline
3y 0m
Avg Prosecution
45 currently pending
Career history
682
Total Applications
across all art units

Statute-Specific Performance

§101
0.4%
-39.6% vs TC avg
§103
50.9%
+10.9% vs TC avg
§102
17.0%
-23.0% vs TC avg
§112
26.5%
-13.5% vs TC avg
Black line = Tech Center average estimate • Based on career data from 637 resolved cases

Office Action

§103 §112
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 claims 1-16 in the reply filed on 01/06/2026 is acknowledged. Claims 17-19 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 01/06/2026. Claim Rejections - 35 USC § 112 Claims 12-14 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention. The term “low-pressure discharge” in claim 12 is a relative term which renders the claim indefinite. The term “low-pressure” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. Claims 13-14 are dependent of claim 12. 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. This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention. Claim(s) 1-3, 5, 10 and 15-16 is/are rejected under 35 U.S.C. 103 as being unpatentable over Whitson et al. (US 2024/0343612A1), in view of Ji et al. (Environmental Science and Pollution Research (2023) 30:23372–23385), and Bekri-Abbes et al. (J Polym Environ (2006) 14:249–256). Regarding claim 1, Whitson teaches a method directed to purifying a produced water (refer abstract disclosing removal of at least one metal from produced water) using a sorbent, comprising: placing the sorbent into an aqueous solution (Refer step 110 in fig. 1); injecting carbon dioxide into the aqueous solution (Refer [0008]; and adsorbing bivalent alkaline earth cations on the surface of the sorbent in a solution (refer [0011]). Whitson does not teach that solution comprising carbonate ions (CO3-2 ) to form carbonate crystals on the surface of the sorbent. However, injecting CO2 in produced water having metal ions (such as sodium, calcium) would result in carbonate ions which reacts with metal ions to form metal crystals. Whitson does not teach that the sorbent comprises nanomembrane made from polymeric waste, wherein the nanomembrane is functionalized with carboxyl groups. Ji teaches removal of heavy metal ions from aqueous solution using polyacrylonitrile nanofibers (refer abstract), wherein the nanofibers are functionalized with carboxyl group (Refer page 23374). It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of Whitson to use polymeric nanofibers functionalized with carboxylic groups to provide excellent properties such as high elasticity, high strength, excellent heat resistance, good acid resistant, low price, and wide application range as taught by Ji (Refer Page 233373/left column). Modified Whitson does not teach that the nanomembrane is formed from polymeric waste, however, Bekri-Abbes discloses converting polymeric waste into cation exchange resin for removal of metals from aqueous solution (Refer abstract). It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of modified Whitson to use polymeric waste in making of nanomembrane to enable recycling of polymeric waste as taught by Bekri-Abbes (Refer abstract, P249). Regarding claims 2-3, Modified Whitson teaches limitations of claim 1 as set forth above. Ji discloses advantages of sorbent being in nanofiber form (refer 233373/left column), and Bekri-Abbes teaches recycling of polymeric waste in making of sorbent. In view of advantages disclosed by Ji and Bekri-Abbes, it would have been obvious to one of ordinary skill in the art to make the nanofibrous membrane from waste polymer for removal of ions from produced water. Regarding claim 5, Modified Whitson teaches limitations of claim 1 as set forth above. Whinston further teaches exposing the sorbent to HCl to enable removal of salts (Refer [0053]). Regarding claim 10, Modified Whitson teaches limitations of claim 1 as set forth above. Bekri-Abbes teaches that the polymeric waste is polystyrene. Regarding claims 15-16, Modified Whitson teaches limitations of claim 1 as set forth above. Whinston teaches placing the sorbent in wastewater stream in a tank (refer fig. 1). Claim(s) 6-7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Whitson et al. (US 2024/0343612A1), in view of Ji et al. (Environmental Science and Pollution Research (2023) 30:23372–23385), and Bekri-Abbes et al. (J Polym Environ (2006) 14:249–256) as applied to claim 1 above, and further in view of Al-Ahmed et al. (US 2017/0233265A1). Regarding claims 6-7, Modified Whitson teaches limitations of claim 1 as set forth above. Modified Whitson does not teach that the method comprising regenerating the nanomembrane by mechanical treatment, wherein the mechanical treatment comprises subjecting the nanomembrane to sonication. Al-Ahmed teaches a method for removing cations from aqueous solution by contacting the aqueous solution with an adsorbent (abstract). Al-Ahmed also teaches that regeneration of the sorbent can be achieved by soaking the adsorbent in the HCl solution with agitation or ultra-sonication for a period of time (refer [0113]). It would have been obvious to one of ordinary skill in the art to use a known method of sonication as taught by Al-Ahmend in the method of modified Whitson. The Supreme Court in KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 415-421, 82 USPQ2d 1385, 1395-97 (2007) identified a number of rationales to support a conclusion of obviousness which are consistent with the proper "functional approach" to the determination of obviousness as laid down in Graham. Examples of rationales that may support a conclusion of obviousness that apply in this istance: Use of known technique to improve similar devices (methods, or products) in the same way, and applying a known technique to a known device (method, or product) ready for improvement to yield predictable results. Claim(s) 8-9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Whitson et al. (US 2024/0343612A1), in view of Ji et al. (Environmental Science and Pollution Research (2023) 30:23372–23385), and Bekri-Abbes et al. (J Polym Environ (2006) 14:249–256) as applied to claim 1 above, and further in view of Arrosyid et al. (ACS Omega June 2023 8 (26), 23664-23672). Regarding claims 8-9, Modified Whitson teaches limitations of claim 1 as set forth above. Ji teaches combining polymeric nanofibers with activated carbon fiber felt (Refer abstract, Scheme 2). Modified Whitson does not teach electrospinning the polymeric waste into nanofibers. Arrosyid teaches making of water filtration nanofiber membrane from polymeric (polystyrene) waste using electrospinning method (abstract). One of ordinary skill in the art would have had a reasonable expectation of success in using electrospinning method in making of the nanofiber membrane in the method of modified Whiston because Arrosyid discloses that it is known in the art of water treatment to use nanofibers made from electrospinning method. Applying heat or other means of joining/fusing the nanofibers to provide a form that can be used in the method would have been an obvious matter of design choice to one of ordinary skill in the art. Claim(s) 4, and 11-14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Whitson et al. (US 2024/0343612A1), in view of Ji et al. (Environmental Science and Pollution Research (2023) 30:23372–23385), and Bekri-Abbes et al. (J Polym Environ (2006) 14:249–256) as applied to claim 1 above, and further in view of Lin et al. (Journal of CO2 Utilization 53 (2021) 101752). Regarding claims 4, and 11-14, Modified Whitson teaches limitations of claim 1 as set forth above. Modified Whitson does not teach functionalizing surface of nanomembrane by CO2 plasma treatment comprising low-pressure discharge using a plasma equipment forming carboxyl groups on the surface of the nanomembrane. Lin teaches CO2 based plasmas for surface modification of polymeric membrane (abstract), wherein the plasma treatment resulted in carboxyl functional group on surface of the membrane (refer abstract). Lin discloses that in order to form uniform films with high molecular weight, plasma polymerization are carried out at low pressures (refer page 2, left column). It would have been obvious to one of ordinary skill in the art before the effective filing date of invention to modify the method of modified Whitson to functionalizing surface of nanomembrane by CO2 plasma treatment comprising low-pressure discharge using a plasma equipment forming carboxyl groups on the surface of the nanomembrane to provide hydrophilicity and functionalization to membrane surface as taught by Lin. Conclusion Any inquiry concerning this communication or earlier communications from the examiner should be directed to PRANAV PATEL whose telephone number is (571)272-5142. The examiner can normally be reached M-F 6AM-4PM. Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice. If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Bobby Ramdhanie can be reached at (571) 270-3240. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300. Information regarding the status of published or unpublished applications may be obtained from Patent Center. Unpublished application information in Patent Center is available to registered users. To file and manage patent submissions in Patent Center, visit: https://patentcenter.uspto.gov. Visit https://www.uspto.gov/patents/apply/patent-center for more information about Patent Center and https://www.uspto.gov/patents/docx for information about filing in DOCX format. For additional questions, contact the Electronic Business Center (EBC) at 866-217-9197 (toll-free). If you would like assistance from a USPTO Customer Service Representative, call 800-786-9199 (IN USA OR CANADA) or 571-272-1000. /PRANAV N PATEL/Primary Examiner, Art Unit 1777
Read full office action

Prosecution Timeline

Sep 27, 2023
Application Filed
Mar 17, 2026
Non-Final Rejection — §103, §112 (current)

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Study what changed to get past this examiner. Based on 5 most recent grants.

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Prosecution Projections

1-2
Expected OA Rounds
68%
Grant Probability
90%
With Interview (+22.2%)
3y 0m
Median Time to Grant
Low
PTA Risk
Based on 637 resolved cases by this examiner. Grant probability derived from career allow rate.

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