|
| US4278547 | 9 Abr 1979 | 14 Jul 1981 | | Conservation of momentum in a barrier oxidation ditch |
| US4394268 | 14 Sep 1979 | 19 Jul 1983 | | Conversion of plug flow and complete mix aeration basins to barrier oxidation ditches |
| US4443338 | 30 Sep 1982 | 17 Abr 1984 | | Conversion of plug flow and complete mix aeration basins to barrier oxidation ditches |
| US4460471 | 5 Mar 1982 | 17 Jul 1984 | | Flow-control process for an oxidation ditch |
| US4532038 | 11 May 1983 | 30 Jul 1985 | | Flow control apparatus for aerobic sewage treatment |
