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. 08, 2002
Filed:
Feb. 22, 2000
Riad A. Al-Samadi, Burlington, Ontario, CA;
Other;
Abstract
Disclosed is an economical single stage membrane process intended to provide very high overall water recoveries from natural sources or wastewater containing high concentrations of hardness and other inorganic scale-forming compounds while preventing scale formation on the membrane and prolonging the useful life of the membrane. The water is first pre-treated in order to separate all suspended matter using a suitable oil separation device, dissolved air flotation, coagulation, flocculation, clarification, single or multi-media filtration, ultra-filtration, micro-filtration or a suitable combination of these pre-treatment steps. The pre-treated water is then purified using a simple, economical single stage membrane system operating at a suitable pressure depending on the water TDS and desired permeate recovery. In order to prevent scale formation on the membranes, the membrane concentrate is softened using a “low-cost” ion exchange softening resin with high selectivity for hardness precursors. The softened, suspended solids free, high TDS concentrate is recycled at a sufficient rate and blended with the high-hardness Influent Water in order to provide further, purification, thus achieving the desired high permeate recoveries while preventing scale formation. A small volume of membrane concentrate is bled out of the system in order to control the osmotic pressure.