Water treatment system and water treatment method

Patent metadata

Field	Value
Publication number	US-2016122219-A1
Application number	US-201414894816-A
Country	US
Kind code	A1
Filing date	Jul 1, 2014
Priority date	Jul 3, 2013
Publication date	May 5, 2016
Grant date	—

Abstract

This water treatment system comprises: a reverse osmosis device ( 2 ); a biofilm treatment device ( 4 ) that has a media on the surface of which a biofilm is formed and that treats water to be treated ( 3 ) before passing through the reverse osmosis device ( 2 ); an oxidizing agent addition device ( 5 ) that adds an oxidizing agent to the water to be treated ( 3 ) at a stage before treatment with the biofilm treatment device ( 4 ) or adds an oxidizing agent to the water to be treated ( 3 ) at a later stage after treatment with the biofilm treatment device ( 4 ) and before treatment with the reverse osmosis device ( 2 ); and a reducing agent addition device ( 6 ) that neutralizes the oxidizing agent by adding a reducing agent to the early stage water to be treated ( 3 ) or the later stage water to be treated ( 3 ).

First claim

1 - 4 . (canceled)

5 . A water treatment system comprising a reverse osmosis membrane device configured to separate water to be treated into concentrated water having a high solute concentration and fresh water, the water treatment system comprising:
a biofilm treatment device comprising a media having biofilm formed on a surface thereof and configured to treat the water to be treated before the water passes through the reverse osmosis membrane device; an oxidizing agent addition device configured to add an oxidizing agent to the water to be treated of a pre-stage before treatment by the biofilm treatment device or the water to be treated of a post-stage before treatment by the reverse osmosis membrane device and after treatment by the biofilm treatment device; and a reducing agent addition device configured to add a reducing agent to the water to be treated of the pre-stage when the oxidizing agent addition device adds the oxidizing agent to the water to be treated of the pre-stage before treatment by the biofilm treatment device, or add a reducing agent to the water to be treated of the post-stage when the oxidizing agent addition device adds the oxidizing agent to the water to be treated of the post-stage before treatment by the reverse osmosis membrane device and after treatment by the biofilm treatment device to neutralize the oxidizing agent.

6 . The water treatment system according to claim 5 , further comprising a mixing device configured to mix the water to be treated to which at least one of the oxidizing agent and the reducing agent of the pre-stage or the post-stage is added.

7 . A water treatment method comprising:
a fresh water separation process of separating water to be treated into concentrated water having a high solute concentration and fresh water by a reverse osmosis membrane; a biofilm treatment process of treating the water to be treated by biofilm formed on a surface of a media before the water passes through the reverse osmosis membrane; an oxidizing agent addition process of adding an oxidizing agent to the water to be treated of a pre-stage before treatment by the biofilm treatment process or the water to be treated of a post-stage before treatment by the fresh water separation process and after treatment by the biofilm treatment process; and a reducing agent addition process of adding a reducing agent to the water to be treated of the pre-stage when the oxidizing agent addition device adds the oxidizing agent to the water to be treated of the pre-stage before treatment by the biofilm treatment device, or adding a reducing agent to the water to be treated of the post-stage when the oxidizing agent addition device adds the oxidizing agent to the water to be treated of the post-stage before treatment by the reverse osmosis membrane device and after treatment by the biofilm treatment device to neutralize the oxidizing agent.

8 . The water treatment method according to claim 7 , further comprising a mixing process of mixing the water to be treated to which at least one of the oxidizing agent and the reducing agent of the pre-stage or the post-stage is added.

Assignees

• Aqua Systems Ltd
• Mitsubishi Heavy Ind Ltd

Inventors

• Tabata Masayuki
• Ito Yoshiaki
• Matsui Katsunori
• Tokunaga Kiichi
• Ike Takashi
• Takeuchi Kazuhisa
• Iwahashi Hideo
• Yasunaga Takeshi
• Kishi Masahiro

Classifications

• B01D61/04 Primary

  Feed pretreatment · CPC title

• B01D61/025

  Reverse osmosis; Hyperfiltration · CPC title

• C02F1/441

  by reverse osmosis · CPC title

• C02F2303/18

  Removal of treatment agents after treatment · CPC title

• C02F1/70

  by reduction {(C02F1/4676 takes precedence)} · CPC title