The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Aug. 28, 1979
Filed:
Jan. 05, 1978
Wolfgang Zimmermann, Kelkheim, DE;
Hermann Schindler, Hofheim am Taunus, DE;
Hoechst Aktiengesellschaft, Frankfurt am Main, DE;
Abstract
In order to protect the environment from pollution, it is desirable to keep the polyvinyl alcohol content in waste waters as low as possible. Polyvinyl alcohol may be removed from waste waters by means of microorganisms on the the one hand, and on the other according to chemical/mechanical methods by salting-out and precipitation and subsequent separation of the solids. Advantageous is the precipitation in the form of a polyvinyl alcohol/boric acid/didiol complex, especially by means of alkaline earth metal hydroxides in an alkaline medium. Calcium hydroxide is a particularly suitable alkaline earth metal hydroxide.