C02F 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)
Description
Covers chemical and physical processes for purifying, conditioning, or processing water, waste water, sewage, and sludge streams. Includes desalination, softening, disinfection, removal of suspended solids and dissolved contaminants, odor control, and sludge dewatering or disposal methods. This subclass encompasses treatment technologies such as coagulation, filtration, ion exchange, biological treatment, and oxidation processes applied across municipal, industrial, and agricultural applications.
Filing statistics
CPC subclass C02F recorded 316,465 patent applications worldwide between 2013 and 2023. Annual filings grew from 12,795 in 2013 to 28,600 in 2023 (+124%), peaking at 39,882 applications in 2018. The most active applicants in class C02 are CHINESE ACADEMY OF SCIENCES (2,531 applications), SINOPEC (CHINA PETROCHEMICAL CORPORATION) (1,700 applications) and KURITA WATER IND (1,287 applications).
Source: EPO PATSTAT, worldwide filings
15 direct subcodes
Child Classifications
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- C02F 1/00 Treatment of water, waste water, or sewage (C02F3/00 - C02F9/00 take precedence)
- C02F 11/00 Treatment of sludge; Devices therefor
- C02F 2101/00 Nature of the contaminant
- C02F 2103/00 Nature of the water, waste water, sewage or sludge to be treated
- C02F 2201/00 Apparatus for treatment of water, waste water or sewage
- C02F 2203/00 Apparatus and plants for the biological treatment of water, waste water or sewage
- C02F 2209/00 Controlling or monitoring parameters in water treatment
- C02F 2301/00 General aspects of water treatment
- C02F 2303/00 Specific treatment goals
- C02F 2305/00 Use of specific compounds during water treatment
- C02F 2307/00 Location of water treatment or water treatment device
- C02F 3/00 Biological treatment of water, waste water, or sewage
- C02F 5/00 Softening water; Preventing scale; Adding scale preventatives or scale removers to water, e.g. adding sequestering agents (softening using ion-exchange C02F1/42)
- C02F 7/00 Aeration of stretches of water
- C02F 9/00 Multistage treatment of water, waste water or sewage
Top Applicants
Top 10 applicants by patent filingsfor class C02, 2013–2023, worldwide · Source: EPO PATSTAT
- CHINESE ACADEMY OF SCIENCES 2,531
- SINOPEC (CHINA PETROCHEMICAL CORPORATION) 1,700
- KURITA WATER IND JP 1,287
- TONGJI UNIVERSITY 1,040
- CHANGZHOU UNIVERSITY 928
- ECOLAB US 904
- HARBIN INSTITUTE OF TECHNOLOGY 904
- BEIJING UNIVERSITY OF TECHNOLOGY 878
- HOHAI UNIVERSITY 862
- EVOQUA WATER TECHNOLOGIES US 842