JPH06190275A - Adsorbing and removing material of metallic compound - Google Patents

Abstract

PURPOSE:To remove a trace amount of nonionic metallic compound in water, and to use it for a ultrapure water purification system too, since TOC elution from a removing material is little, by using the adsorbing and removing material for netallic nonionic compound in water, consisting of a hydrohobic synthetic resin granulate. CONSTITUTION:The adsorbing and removing material for metallic compound is constituted of the hydrohobic synthetic resin granulate of polytetrafluoroethylene, etc. The nonionic metallic compounds of Fe, Al and Cu, etc., present on in a trace amount in water can efficiently be adsorbed and removed by bringing the adsorbing and removing material into contact with water. Also since the TOC elution from the material is little, it can used for the ultrapure water production system.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a separating material for adsorbing and removing a trace amount of nonionic metal compounds existing in water.

[0002]

2. Description of the Related Art Activated carbon and membranes are used as a separating material for nonionic substances in water.

[0003]

The conventional separation material as described above has a limited range of application because it contains a large amount of pollutants such as TOC components eluted from itself. For example, in an ultrapure water production system, activated carbon or a reverse osmosis membrane is used for the purpose of removing nonionic substances in a primary pure water system, but a separation material for such a purpose is usually used in a secondary pure water system. not being used. For this reason, in the secondary system, nonionic substances are adsorbed on the surface of the ion exchange resin and ultrafiltration membrane, which are its constituent units, and adversely affect their original purpose of removing ionic substances and fine particles. There is.

An object of the present invention is to solve the conventional problems and to provide a non-ionic metal compound adsorption / removal material which is less likely to elute TOC from a separation material and which can be used in an ultrapure water production system. .

[0005]

In the present invention, a hydrophobic synthetic resin granular material is used as a nonionic metal compound adsorption / removal material in water. As the hydrophobic synthetic resin, polytetrafluoroethylene (PTFE), polyethylene (PE),
Polypropylene (PP), polyetheretherketone (PEEK), polyvinyl difluoride (PVDF),
A highly hydrophobic synthetic resin such as polyvinyl chloride (PVC) can be used. The granular material preferably has a particle diameter of 50 μm to 5 mm, and the finer the particle, the larger the contact area. However, an appropriate particle diameter can be selected according to the place of use in consideration of the loss pressure during water passage.

Prior to use, the synthetic resin granules are washed in advance to be in a clean state. The cleaning is performed, for example, by contacting with acetone, a hydrochloric acid mixed solution, an alcohol solution, a hydrochloric acid solution, or the like. After washing with the solution, wash with pure water until the pH becomes neutral. The cleaned synthetic resin is effective for separating trace amounts of nonionic metal compounds present in water from water. As the nonionic compound, iron hydroxide, aluminum hydroxide, nickel hydroxide, copper hydroxide and the like are targeted, and are suitable for removing a metal present in water in a trace amount of ppm concentration or less.

[0007]

By filling the column with the hydrophobic synthetic resin of the present invention and passing water containing a trace amount of the nonionic metal compound through the column, the metal compound comes into contact with the resin and is adsorbed and removed. The water flow conditions may be arbitrary, and water is usually passed at an SV of about 10 to 50.

[0008]

【Example】

Example 1 A column having a diameter of 20 mm and a perforated plate (pore size 50 μm) at the bottom was placed in a column containing polytetrafluoroethylene (P
Granules of TFE (particle size 150 μm) were filled in such an amount that the layer height was 210 mm. Fill the column with alcohol and immerse it, and then pass 1 liter of water, followed by 10%
1 liter of hydrochloric acid was passed through, and ultrapure water was further supplied to wash it until the pH reached 7. Ferric chloride, aluminum chloride, and copper nitrate are dissolved in ultrapure water so that Fe, Al, and Cu are each 1000 ppm, and then diluted with ultrapure water until each metal reaches 10 ppb. And Raw water was passed down the column at a rate of 16 ml / min. The metal concentration of the treated water was measured by the flameless atomic absorption photometry. As a result, the concentration of each metal in the treated water was Fe 1.5 ppb, Al 1.5 ppb, Cu 3.
It was 0 ppb, and the removal effect was recognized.

Example 2 A column having a diameter of 70 mm and a height of 400 mm was packed with PTFE in an amount of 1500 cubic centimeters and washed with alcohol and hydrochloric acid in the same manner as in Example 1. Ultrapure water having a specific resistance of 16 MΩ · cm and a TOC concentration of 3 ppb was passed through this column. When the TOC of the treated water was measured, the TOC
The concentration was 3 ppb, and no TOC was eluted from the synthetic resin.

[0010]

As described above, according to the adsorption / removal material of the present invention, a nonionic metal compound present in a trace amount can be effectively separated and removed by contacting with water. Moreover, there is no TOC elution from the separation material, and it can be applied to an ultrapure water production system.

Claims (1)

[Claims] 1. A nonionic metal compound adsorption / removal material in water comprising a hydrophobic synthetic resin granular material.