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:
Oct. 31, 1995
Filed:
Mar. 28, 1994
Robert G Guess, Beverly, MA (US);
Romar Technologies, Inc., Beverly, MA (US);
Abstract
A process for removing dissolved oils and greases from an aqueous solution which also may contain dissolved heavy metals is provided wherein the aqueous solution is mixed with a source of ferrous ion and dithionite ion in a first step at acidic pH to reduce and permit removal of solid heavy metal, is present and to separate oils and greases from the aqueous solution. Solution from the first step if reacted in a second step with hydroxide slurries obtained from third and fourth steps. A second step solution from the second step is reacted in a third step with an alkali composition and a third solution. Optionally, the third solution is reacted with a chelating agent for iron and an oxidizer in a fourth step. A solution of chelated iron from the fourth step, when practical is disposed of. Oils and greases are recovered from the first step such as by skimming.