Desalination system and desalination method

Patent metadata

Field	Value
Publication number	US-9988294-B2
Application number	US-201715403661-A
Country	US
Kind code	B2
Filing date	Jan 11, 2017
Priority date	Aug 26, 2011
Publication date	Jun 5, 2018
Grant date	Jun 5, 2018

Abstract

This desalinization system, which obtains industrial-use water and drinking water from seawater and wastewater, is provided with: a purification device that purifies wastewater by removing activated sludge therefrom; a first RO membrane that removes salt from the output of the purification device by transferring said salt to first concentrated water, thereby producing industrial-use water; a UF membrane that seawater passes through and that removes particulates from said seawater; a second RO membrane that removes salt from the treated output of the UF membrane by transferring said salt to second concentrated water, producing drinking water; an agitation device to which the second concentrated water from the second RO membrane and the first concentrated water from the first RO membrane are sent to be agitated; and a third RO membrane removing salt from the liquid mixture agitated by the agitation device by transferring said salt to third concentrated water, producing industrial-use water.

First claim

The invention claimed is:

1. A sea-water desalination method for preparing industrial water and drinking water from sea-water and sewage water, the method comprising
producing a first stream of industrial water by making the sewage water permeate a permeation apparatus and a first RO membrane;
producing drinking water by making sea-water permeate a UF membrane and a second RO membrane;
producing a mixture fluid by mixing a first concentrated water removed by the first RO membrane and a second concentrated water removed by the second RO membrane; and
producing a second stream of industrial water by making a the mixture fluid permeate a third RO membrane,
wherein the drinking water is prepared exclusively from the sea-water.

2. A sea-water desalination method according to claim 1 , comprising recovering at least either of pressure energy of the second concentrated-water removed by the second RO membrane or pressure energy of a third concentrated-water removed by the third RO membrane.

Assignees

• Hitachi Ltd

Inventors

• SEKINE Yasunori
• Noto Kazuhiko
• Sasaki Akira
• Kitamura Kotaro

Classifications

• C02F3/1268

  Membrane bioreactor systems · CPC title

• C02F2303/10

  Energy recovery · CPC title

• B01D61/145

  Ultrafiltration · CPC title

• B01D61/58

  Multistep processes · CPC title

• C02F1/441 Primary

  by reverse osmosis · CPC title