C02 TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
Description
Class C02 encompasses technologies and processes for treating water, wastewater, sewage, and sludge to remove contaminants, improve water quality, or enable safe disposal and resource recovery. This includes physical, chemical, and biological treatment methods such as filtration, coagulation, disinfection, aeration, biological oxidation, and sludge processing. The classification covers both municipal and industrial water treatment applications, as well as specialized processes for specific contaminant removal (e.g., heavy metals, organic pollutants, nutrients). Adjacent classes address related but distinct areas such as desalination and demineralization under C02C and specific chemical processes applicable to water treatment under their respective chemistry classes.
Filing statistics
CPC C02 recorded 316,465 patent applications worldwide between 2013 and 2023, summed across its 1 subclasses. 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
1 direct subcode
Child Classifications
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- 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)
Top Applicants
Top 10 applicants by patent filings, 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