CN-122029133-A - Water treatment device and operation method for water treatment device

CN122029133ACN 122029133 ACN122029133 ACN 122029133ACN-122029133-A

Abstract

The water treatment device (1) has a plurality of unit devices for performing unit operations of water treatment, and each of the unit devices includes a reverse osmosis membrane device (6) to which water to be treated is supplied, and an electrically regenerated deionizing device (8) to which permeate water from the reverse osmosis membrane device (6) is supplied, and ions in the permeate water are removed to produce treated water, and concentrated water containing the removed ions is discharged. And cleaning at least one unit device other than the electrically regenerated deionizing device (8) among the plurality of unit devices using cleaning water containing concentrated water discharged from the electrically regenerated deionizing device (8).

Inventors

Chinese village courageously
TAKAHASHI KAZUSHIGE
SASAKI RYOSUKE

Assignees

奥加诺株式会社

Dates

Publication Date: 20260512
Application Date: 20240920
Priority Date: 20231023

Claims (10)

1. A water treatment apparatus having a plurality of unit devices for performing unit operations of water treatment, The plurality of unit devices includes: a reverse osmosis membrane device to which water to be treated is supplied, and An electrically regenerated deionizing device which removes ions in permeate water supplied to the reverse osmosis membrane device to generate treated water and discharges concentrated water containing the removed ions, The water treatment device cleans at least one unit device other than the electrically regenerative deionization device among the plurality of unit devices using cleaning water containing the concentrated water discharged from the electrically regenerative deionization device.
2. The water treatment device according to claim 1, wherein, The water treatment apparatus has an adjusting unit that adjusts pH on a front stage side of the electrically regenerative deionization apparatus so that the concentrated water discharged from the electrically regenerative deionization apparatus is alkaline.
3. A water treatment apparatus according to claim 2, wherein, The operation conditions of the electrically regenerative deionization apparatus are set so that the pH value of the concentrated water discharged from the electrically regenerative deionization apparatus is higher than the pH value of the permeate water of the reverse osmosis membrane apparatus.
4. A method of operating a water treatment apparatus according to claim 3, wherein, The operation conditions of the reverse osmosis membrane device and the electrically regenerative deionization device are set so that the pH of the permeate water of the reverse osmosis membrane device becomes 8 or more and the pH of the concentrate water discharged from the electrically regenerative deionization device becomes 9 or more.
5. A water treatment apparatus according to claim 2, wherein, The water treatment device comprises: An alkali adding device for adding an alkali agent to the water to be treated, and A pH meter for measuring a pH value of the permeate water of the reverse osmosis membrane device or the concentrate water discharged from the electrically regenerated deionization device, The water treatment device adjusts the addition amount of the alkaline agent added by the alkaline addition device so that the measured value of the pH meter becomes a given value or more.
6. The water treatment apparatus according to claim 5, wherein, The water treatment apparatus includes a control unit that adjusts the amount of the alkaline agent to be added so that the pH of the permeate water of the reverse osmosis membrane apparatus becomes 8 or more or the pH of the concentrated water discharged from the electrically regenerative deionization apparatus becomes 9 or more based on the measured value of the pH meter.
7. The water treatment device according to any one of claims 1 to 6, wherein, The water treatment device is provided with a medicine adding device, and the medicine adding device adds more than one of an acid agent, an alkaline agent, an oxidant, a dispersing agent and a slime control agent to the cleaning water.
8. The water treatment device according to any one of claims 1 to 6, wherein, The water treatment device comprises: A washing water tank for storing the concentrated water discharged from the electrically regenerative deionization device as the washing water; a water quality measuring section for measuring the water quality of the concentrated water discharged from the electrically regenerated deionizing device, and A storage tank provided on an inlet side of any one of the plurality of unit devices on a front stage side of the electrically regenerative deionization device, When the measured value of the water quality measuring unit exceeds a threshold value, the water treatment device switches the supply destination of the concentrated water discharged from the electrically regenerative deionization device from the washing water tank to the storage tank.
9. The water treatment device according to any one of claims 1 to 6, wherein, The water treatment device comprises: A washing water tank for storing the concentrated water discharged from the electrically regenerative deionization device as the washing water; A water level gauge for measuring the water level of the cleaning water stored in the cleaning water tank, and A storage tank provided on an inlet side of any one of the plurality of unit devices on a front stage side of the electrically regenerative deionization device, When the measured value of the water level gauge exceeds a threshold value, the water treatment device switches the supply destination of the concentrated water discharged from the electrically regenerative deionization device from the washing water tank to the storage tank.
10. A method of operating a water treatment apparatus having a plurality of unit devices for performing unit operations of water treatment, The plurality of unit devices include a reverse osmosis membrane device to which water to be treated is supplied, and an electrically regenerated deionizing device to which permeate water of the reverse osmosis membrane device is supplied, which removes ions in the permeate water to generate treated water, and which discharges concentrated water containing the removed ions, In the method of operating the water treatment apparatus, at least one unit apparatus other than the electrically regenerative deionization apparatus among the plurality of unit apparatuses is cleaned using cleaning water containing the concentrated water discharged from the electrically regenerative deionization apparatus.

Description

Water treatment device and operation method for water treatment device Technical Field The present invention relates to a water treatment apparatus and a method of operating the same. Background As a water treatment apparatus for producing primary purified water, a water treatment apparatus equipped with an RO-EDI system including a Reverse Osmosis (RO) membrane apparatus and an electrically regenerative deionization apparatus (EDI) is known. In the RO-EDI system, water to be treated is supplied to the RO membrane device, and permeate water from the RO membrane device is treated with EDI. In general, pretreatment such as sand filtration, coagulation, turbidity removal, activated carbon, softening, ion exchange, and decarbonation is performed at the stage preceding the RO membrane apparatus. Patent document 1 describes an RO-EDI system comprising a brine RO membrane device for treating concentrated water of each of the RO membrane device and EDI, and returning permeate water of the brine RO membrane to the water to be treated. Patent document 2 describes a technique for returning the EDI concentrated water used for producing pure water to the water to be treated. In the RO-EDI system described above, unit devices (for example, a sand filtration device, an activated carbon device, a decarbonation device, an RO membrane device, etc.) that perform unit operations of water treatment are contaminated with impurities (turbidity, particles, organic matter, organisms, biological metabolites, scale components, etc.) during the treatment. Therefore, it is necessary to clean the unit device with clear water or cleaning water to which a cleaning chemical is added. Although not an RO-EDI system, patent document 3 describes a technique in which a multistage RO membrane apparatus is provided, permeate water of each RO membrane apparatus is stored in a tank, and the stored water stored in the tank is used as washing water to wash each RO membrane apparatus. Prior art literature Patent literature Patent document 1 Japanese patent laid-open publication No. 2020-146618 Patent document 2 Japanese patent laid-open No. 11-244854 Patent document 3 Japanese patent application laid-open No. 2017-209554 Disclosure of Invention Technical problem to be solved by the invention In the RO-EDI system described above, in the case of cleaning a unit device that performs a unit operation, if the cleaning water is neutral, a sufficient cleaning effect may not be obtained. On the other hand, the cleaning effect can be improved by cleaning the unit device by preparing cleaning water to which a chemical is added. However, in this case, there is a problem that the equipment cost and the medicine cost are increased. When permeate water of the RO membrane device is used as the washing water, an increase in equipment cost and medicine cost can be suppressed. However, in this case, if the washing water is neutral, there is a problem that a sufficient washing effect cannot be obtained. The present invention aims to provide a water treatment apparatus and an operation method thereof, which can solve the above problems, inhibit the increase of equipment cost and medicine cost, and improve the cleaning effect of a unit device for unit operation. Technical scheme for solving technical problems In order to achieve the above object, according to one aspect of the present invention, there is provided a water treatment apparatus including a plurality of unit devices for performing a unit operation of water treatment, the plurality of unit devices including a reverse osmosis membrane device to which water to be treated is supplied, and an electrically regenerated deionizing device to which permeate water of the reverse osmosis membrane device is supplied, for removing ions in the permeate water to generate treated water, and for discharging concentrated water containing the removed ions, the water treatment apparatus cleaning at least one unit device other than the electrically regenerated deionizing device among the plurality of unit devices using cleaning water containing the concentrated water discharged from the electrically regenerated deionizing device. According to another aspect of the present invention, there is provided a method for operating a water treatment apparatus including a plurality of unit apparatuses for performing a unit operation of water treatment, the plurality of unit apparatuses including a reverse osmosis membrane apparatus to which water to be treated is supplied, and an electrically regenerated deionizing apparatus to which permeate water of the reverse osmosis membrane apparatus is supplied, for removing ions in the permeate water to generate treated water, and for discharging concentrated water containing the removed ions, wherein at least one unit apparatus other than the electrically regenerated deionizing apparatus among the plurality of unit apparatuses is cleaned using cleaning water containing the concentrated water dischar