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:
Apr. 07, 1981
Filed:
Nov. 15, 1978
John D Cassidy, Ambler, PA (US);
Lester Steinbrecher, Southampton, PA (US);
Amchem Products, Inc., Ambler, PA (US);
Abstract
A process is disclosed for the removal of chrome from waste water containing chrome in addition to at least one chelating agent for trivalent chromium. The chrome-containing waste water is treated at low pH with both a reducing agent suitable for converting hexavalent chrome to trivalent chrome and with a ferric or aluminum sulfate or chloride salt. Following the reduction step, the pH of the now acidic solution is raised, using an inorganic base, to a pH sufficient to cause the formation of chromic hydroxide. The process of this invention is particularly suitable where rapid sedimentation processes, such as are achievable by the use of the lamella separator, are contemplated.