C02F 3/1257
Oxidation ditches
Official title: {Oxidation ditches}
C02F3/1257 (Oxidation ditches) appears on 135 US grants and 51 published applications in this corpus.
Search patents in C02F- Granted patents
- 135
- Published applications
- 51
- Assignees
- 69
- Inventors
- 211
- Latest grant
- 3 Mar 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 8 | 0 |
| 1977 | 3 | 0 |
| 1978 | 1 | 0 |
| 1979 | 3 | 0 |
| 1980 | 4 | 0 |
| 1981 | 6 | 0 |
| 1982 | 2 | 0 |
| 1983 | 3 | 0 |
| 1984 | 10 | 0 |
| 1985 | 7 | 0 |
| 1986 | 4 | 0 |
| 1987 | 3 | 0 |
| 1988 | 4 | 0 |
| 1989 | 6 | 0 |
| 1990 | 7 | 0 |
| 1991 | 1 | 0 |
| 1992 | 3 | 0 |
| 1993 | 2 | 0 |
| 1994 | 2 | 0 |
| 1995 | 3 | 0 |
| 1996 | 4 | 0 |
| 1997 | 3 | 0 |
| 1998 | 3 | 0 |
| 1999 | 1 | 0 |
| 2000 | 0 | 0 |
| 2001 | 1 | 1 |
| 2002 | 1 | 1 |
| 2003 | 1 | 0 |
| 2004 | 0 | 0 |
| 2005 | 0 | 1 |
| 2006 | 0 | 1 |
| 2007 | 1 | 1 |
| 2008 | 2 | 2 |
| 2009 | 1 | 2 |
| 2010 | 3 | 4 |
| 2011 | 3 | 1 |
| 2012 | 3 | 4 |
| 2013 | 0 | 1 |
| 2014 | 1 | 2 |
| 2015 | 3 | 4 |
| 2016 | 1 | 5 |
| 2017 | 1 | 5 |
| 2018 | 2 | 3 |
| 2019 | 3 | 0 |
| 2020 | 4 | 4 |
| 2021 | 3 | 5 |
| 2022 | 4 | 1 |
| 2023 | 1 | 3 |
| 2024 | 0 | 0 |
| 2025 | 0 | 0 |
| 2026 | 3 | 0 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Integrated dual circulation oxidization ditch apparatus for municipal wastewater and treatment method3 Mar 2026US 12,565,435 B2Guizhou University
- System and method for indirect measurement of oxygen utilization rate and influent load for aeration control24 Feb 2026US 12,559,396 B2Xylem Water Solutions U.S.A., Inc.
- Distributed wastewater collection, treatment and reuse system with integrated, intelligent wildfire defense20 Jan 2026US 12,527,981 B2
- Biological phosphorus and nitrogen removal in activated sludge processing7 Nov 2023US 11,807,562 B2Dentro-P, LLC
- Sludge dehydration system and sludge dehydration method2 Aug 2022US 11,401,188 B2Ishigaki Company Limited
- System and Method for Indirect Measurement of Oxygen Utilization Rate and Influent Load for Aeration Control4 May 2023US 2023/0139472 A1Xylem Water Solutions U.S.A., Inc.
- Distributed wastewater collection, treatment and reuse system with integrated, intelligent wildfire defense23 Mar 2023US 2023/0091027 A1
- Integrated dual circulation oxidization ditch apparatus for municipal wastewater and treatment method26 Jan 2023US 2023/0024100 A1Guizhou University
- Biological phosphorus and nitrogen removal in activated sludge processing18 Aug 2022US 2022/0259084 A1Dentro-P, LLC
- Method for ecologic configuration of oil production high-salt wastewater artificial wetland to realize up-to-standard operation in winter30 Dec 2021US 2021/0403355 A1Dongying Zhengze Environmental Technology Co., Ltd.
Most cited
By later US patents
- Waste treatment system having integral intrachannel clarifier111US 4,446,018 AArmco Inc. · 1984
- Improvements in and relating to waste water treatment96US 3,964,998 ASouth African Inventions Development Corporation · 1976
- Solid-liquid separator92US 5,451,317 AKubota Corporation · 1995
- Gas production by accelerated in situ bioleaching of landfills80US 4,323,367 AInstitute of Gas Technology · 1982
- Aquaculture wastewater treatment system and method of making same70US 6,447,681 B1Kent Sea Tech Corporation · 2002