Abstract: A method of making a polyurea by reacting an aliphatic diamine with trimelisocyanatosilane under pressure in a closed vessel at a temperature sufficiently high and for a time sufficiently long to produce a substantial quantity of the polyurea.
Type:
Grant
Filed:
March 31, 1975
Date of Patent:
February 24, 1976
Assignee:
The United States of America as represented by the Secretary of the Army
Abstract: Total removal of cellulose nitrate particles from a waste water stream is accomplished by a combination of chemical and biological treatments which result in an effluent having a greatly reduced concentration of nitrogen compounds and having an acceptable BOD. The first step in the process requires that the insoluble, non-biodegradable cellulose nitrate particles be chemically digested with alkali to produce soluble products. Following digestion, the waste stream is supplemented with domestic raw sewage and a microbially utilizable carbon source and the supplemented waste stream is subjected first to an anaerobic microbial denitrification treatment to eliminate the oxidized forms of nitrogen and then to an aerobic microbial treatment to reduce BOD and to oxidize reduced nitrogen compounds.
Type:
Grant
Filed:
February 4, 1975
Date of Patent:
February 17, 1976
Assignee:
The United States of America as represented by the Secretary of the Army