Issued Patents All Time
Showing 26–27 of 27 patents
| Patent # | Title | Co-Inventors | Date |
|---|---|---|---|
| 6325933 | Process for biological purification of waste water under sludge retention | Marinus Nielsen | 2001-12-04 |
| 6238562 | Process for biological purification of waste water with reversing operation | Marinus Nielsen | 2001-05-29 |