C02F
Treatment of water, waste water, sewage, or sludge
Official title: TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE (separation in general B01D; special arrangements on waterborne vessels of installations for treating water, waste water or sewage, e.g. for producing fresh water, B63J; adding materials to water to prevent corrosion C23F; treating radioactively-contaminated liquids G21F9/04; regeneration of reactants for recirculation into processes, see the relevant places for the processes)
C02F (Treatment of water, waste water, sewage, or sludge) appears on 42,420 US grants and 41,760 published applications in this corpus.
Search patents in C02F- Granted patents
- 42,420
- Published applications
- 41,760
- Assignees
- 16,718
- Inventors
- 77,987
- Latest grant
- 6 Oct 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 558 | 0 |
| 1977 | 498 | 0 |
| 1978 | 494 | 0 |
| 1979 | 370 | 0 |
| 1980 | 500 | 0 |
| 1981 | 526 | 0 |
| 1982 | 419 | 0 |
| 1983 | 367 | 0 |
| 1984 | 386 | 0 |
| 1985 | 373 | 0 |
| 1986 | 363 | 0 |
| 1987 | 461 | 0 |
| 1988 | 478 | 0 |
| 1989 | 562 | 0 |
| 1990 | 534 | 0 |
| 1991 | 612 | 0 |
| 1992 | 662 | 0 |
| 1993 | 705 | 0 |
| 1994 | 639 | 0 |
| 1995 | 696 | 0 |
| 1996 | 719 | 0 |
| 1997 | 732 | 0 |
| 1998 | 754 | 0 |
| 1999 | 812 | 0 |
| 2000 | 846 | 0 |
| 2001 | 935 | 197 |
| 2002 | 818 | 849 |
| 2003 | 778 | 1013 |
| 2004 | 699 | 1129 |
| 2005 | 603 | 1205 |
| 2006 | 652 | 1213 |
| 2007 | 696 | 1207 |
| 2008 | 698 | 1348 |
| 2009 | 663 | 1339 |
| 2010 | 860 | 1564 |
| 2011 | 827 | 1565 |
| 2012 | 886 | 1594 |
| 2013 | 957 | 1728 |
| 2014 | 1080 | 1958 |
| 2015 | 1094 | 1931 |
| 2016 | 1180 | 1986 |
| 2017 | 1348 | 1990 |
| 2018 | 1532 | 2020 |
| 2019 | 1679 | 2087 |
| 2020 | 1750 | 2258 |
| 2021 | 1643 | 2223 |
| 2022 | 1552 | 2095 |
| 2023 | 1439 | 2010 |
| 2024 | 1505 | 2003 |
| 2025 | 1524 | 1840 |
| 2026 | 956 | 1408 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Main groups
Granted patents with any code in the group
- C02F 1/00Treatment of water, waste water, or sewage33,979
- C02F 2103/00Nature of the water, waste water, sewage or sludge to be treatedIndexing code12,582
- C02F 2101/00Nature of the contaminantIndexing code9,011
- C02F 3/00Biological treatment of water, waste water, or sewage8,271
- C02F 2201/00Apparatus for treatment of water, waste water or sewageIndexing code8,195
- C02F 2303/00Specific treatment goalsIndexing code7,962
- C02F 2209/00Controlling or monitoring parameters in water treatmentIndexing code7,435
- C02F 9/00Multistage treatment of water, waste water or sewage4,179
All 15 main groupsShow fewer
- C02F 11/00Treatment of sludge3,333
- C02F 2301/00General aspects of water treatmentIndexing code3,322
- C02F 2305/00Use of specific compounds during water treatmentIndexing code2,706
- C02F 5/00Softening water2,345
- C02F 2307/00Location of water treatment or water treatment deviceIndexing code1,946
- C02F 2203/00Apparatus and plants for the biological treatment of water, waste water orIndexing code655
- C02F 7/00Aeration of stretches of water289
Recent patents
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- Preparation method of high-efficiency gel for seawater desalination6 Oct 2026US 12,752,249 B2Shanghai Maritime University
- Silica-based nanoparticles for PFAS remediation6 Oct 2026US 12,752,323 B2Regents of the University of Minnesota
- Composite filter and water purifier including same6 Oct 2026US 12,753,091 B2Coway Co., Ltd.
- Automated liquid dispensing device8 Oct 2026US 2026/0305569 A1Automated Pet Care Products, LLC d/b/a WHISKER
- Evaporator for ambient water bodies, and related system and method8 Oct 2026US 2026/0306964 A1Resource West, Inc.
- Filtration manifold with integrated bypass8 Oct 2026US 2026/0307010 A1Midea Group Co., Ltd.
- Salt-rejecting continuous passive solar thermal desalination via thin-film condensation8 Oct 2026US 2026/0307012 A1The Regents of the University of California
- Contorted polyamide membranes and methods of use thereof8 Oct 2026US 2026/0307019 A1University of Houston System
Most cited
By later US patents
- Purification of saline water838US 4,036,749 A1977
- Methods and systems for improved dosing of a chemical treatment, such as chlorine dioxide, into a fluid stream, such as a wastewater stream595US 6,949,196 B2Fkos, LLC · 2005
- UV-emitting phosphor and lamp containing same525US 7,396,491 B2Osram Sylvania Inc. · 2008
- Hot water disinfection of dialysis machines, including the extracorporeal circuit thereof490US 5,591,344 AAksys, Ltd. · 1997
- Magnetic iron-dextran microspheres466US 4,452,773 ACanadian Patents and Development Limited · 1984