Granted Patent
Utility
US 5,314,621 · App. 07/850,610
Method for the biological purification of wastewater
Inventor:
Franck Rogalla
Patented Case
View Patent ↗
Granted: May 24, 1994
Filed: Mar 13, 1992
Inventor
Franck Rogalla
Assignee (at issue)
OTV Omnium de Traltements et de Valorisation S.A.
This patent predates the USPTO's electronic file wrapper — prosecution documents from this era exist only in the Patent Office's paper records. A certified copy of the file history can be ordered from the USPTO's paper archives.