C02F 3/121
Multistep treatment
Official title: {Multistep treatment}
C02F3/121 (Multistep treatment) appears on 237 US grants and 176 published applications in this corpus.
Search patents in C02F- Granted patents
- 237
- Published applications
- 176
- Assignees
- 169
- Inventors
- 545
- Latest grant
- 25 Aug 2026
Filings by year
| Year | Granted patents | Published applications |
|---|---|---|
| 1976 | 6 | 0 |
| 1977 | 5 | 0 |
| 1978 | 5 | 0 |
| 1979 | 4 | 0 |
| 1980 | 3 | 0 |
| 1981 | 3 | 0 |
| 1982 | 1 | 0 |
| 1983 | 4 | 0 |
| 1984 | 6 | 0 |
| 1985 | 2 | 0 |
| 1986 | 3 | 0 |
| 1987 | 3 | 0 |
| 1988 | 1 | 0 |
| 1989 | 4 | 0 |
| 1990 | 6 | 0 |
| 1991 | 8 | 0 |
| 1992 | 5 | 0 |
| 1993 | 4 | 0 |
| 1994 | 5 | 0 |
| 1995 | 5 | 0 |
| 1996 | 2 | 0 |
| 1997 | 3 | 0 |
| 1998 | 3 | 0 |
| 1999 | 4 | 0 |
| 2000 | 4 | 0 |
| 2001 | 7 | 0 |
| 2002 | 0 | 2 |
| 2003 | 3 | 5 |
| 2004 | 6 | 3 |
| 2005 | 4 | 2 |
| 2006 | 3 | 4 |
| 2007 | 1 | 5 |
| 2008 | 5 | 6 |
| 2009 | 5 | 2 |
| 2010 | 2 | 4 |
| 2011 | 2 | 8 |
| 2012 | 3 | 5 |
| 2013 | 2 | 4 |
| 2014 | 5 | 15 |
| 2015 | 3 | 10 |
| 2016 | 10 | 8 |
| 2017 | 2 | 9 |
| 2018 | 11 | 15 |
| 2019 | 14 | 10 |
| 2020 | 18 | 17 |
| 2021 | 8 | 15 |
| 2022 | 7 | 7 |
| 2023 | 6 | 4 |
| 2024 | 7 | 7 |
| 2025 | 1 | 6 |
| 2026 | 3 | 3 |
By publication year. Applications have been published since 2001. 2026 runs to 8 Oct.
Recent patents
- Multiple chamber septic tank with a plurality of large and small access ports25 Aug 2026US 12,715,798 B2KleanTu LLC
- Process and system for simultaneous nitrification and denitrification2 Jun 2026US 12,643,803 B2Fluence Water Products and Innovation Ltd
- Method and device to optimize plug flow in an aerobic biological wastewater treatment reactor24 Mar 2026US 12,583,777 B2HaskoningDHV Nederland B.V.
- Combined mixed-cell and raceway aquaculture device, system and method of use thereof, and method for growing fish thereby25 Nov 2025US 12,478,047 B2Jlh Consulting Inc.
- Container-type apparatus with a suspended particle system for wastewater treatment10 Dec 2024US 12,161,953 B2Wesdon-Tienda Environmental Sciences Co. Ltd.
- Process and system for simultaneous nitrification and denitrification17 Sep 2026US 2026/0274723 A1Fluence Water Products and Innovation Ltd
- Methods and systems for producing water from a waste stream9 Jul 2026US 2026/0193118 A1Cambrian Innovation, Inc.
- Process and system for simultaneous nitrification and denitrification19 Mar 2026US 2026/0078035 A1Fluence Water Products and Innovation Ltd
- Water treatment device and water treatment method20 Nov 2025US 2025/0353764 A1Organo Corporation
- Granular activated carbon (gac) reactivation waste product enhanced activated sludge system for removing per- and polyfluoroalkyl substances (pfas) from a flow of wastewater and/or landfill leachate30 Oct 2025US 2025/0333340 A1
Most cited
By later US patents
- Multiple zone batch treatment process102US 5,192,442 AZimpro Passavant Environmental Systems, Inc. · 1993
- Wastewater treatment system90US 5,364,529 ALevel Valley Dairy Company · 1994
- Method and system for nitrifying and denitrifying wastewater86US 7,147,778 B1I. Kruger Inc. · 2006
- Method and apparatus for treating wastewater using membrane filters84US 6,863,818 B2CH2M Hill, Inc. · 2005
- Method and apparatus for treating wastewater using membrane filters80US 6,517,723 B1CH2M Hill, Inc. · 2003