JPH08318283A - Water treatment method and apparatus for removing iron component - Google Patents

Abstract

PURPOSE: To enhance the removing rate and recovery properties of a precipitated ion component from water by continuously passing water to be treated through a treatment part packed with a filter medium containing an alkali component possible to elute while aerating the same and subsequently passing the same through a magnet arranged treatment part to attract and remove the precipitated iron component by a magnet. CONSTITUTION: First and second treatment parts 1, 2 are arranged side by side in a horizontal direction and the first treatment part 1 is packed with a mineral filter medium 3 containing a large quantity of a Ca component capable of being eluted into water. A plurality of electromagnets 5 are arranged to the second treatment part 2 in a predetermined arranging pattern. Air is supplied to the first treatment part 1 from the bottom part thereof by an air diffusion pipe 4 to aerate the water to be treated in the first treatment part 1 to precipitate an iron component. The water to be treated wherein the iron component is precipitated is sent to the second treatment part 2 and the precipitated iron component is attracted and removed by the electromagnets 5. The air diffusion pipe 4 is also extended to the bottom part of the second treatment part 2 to diffuse air.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a water treatment technique for removing iron dissolved in water.

[0002]

2. Description of the Related Art For example, an artificial "stream" may be provided in a park or garden by pumping up groundwater. In this case, depending on the type of groundwater, the iron content is high, and this iron content causes the river bed of the "brook" to become reddish as a whole, impairing the landscape. In addition, the groundwater that springs out during construction work may also contain a large amount of iron, and if this is discharged as is to nearby rivers, it will cause redness on the riverbed of the river, causing a kind of environmental damage. Such "reddish phenomenon" caused by iron-containing water can be prevented by removing iron from the iron-containing water. However, there is a problem in its removal method.

Various methods are known for removing iron and other dissolved components from water, such as an ion exchange method, an electrodialysis method, and a reverse osmosis method. However, these are all intended for advanced treatment and require a great deal of cost, and are not generally suitable for treatment of water used for the above-mentioned artificial "stream" or construction wastewater.

Under these circumstances, the applicant of the present application has previously proposed Japanese Patent Application No. 4-284918 (Japanese Patent Laid-Open No. 6-114385).
No.) as a new water treatment technology. This water treatment technology converts iron dissolved in water in the state of ferrous hydroxide [Fe (OH) ₂ ] into insoluble ferric hydroxide [Fe (OH) ₃ ] by aeration, The precipitated iron that precipitates is removed from the water with a filter medium.

This technique has achieved quite good results in that the water treatment for removing iron is carried out without complicated equipment and expensive costs. However, since the removal rate of ferric hydroxide by the filter medium is slow, that is, the removal efficiency per unit time is low, it is necessary to increase the amount of filter medium in order to increase the throughput per unit time. If there are many, there is a drawback that the device structure becomes large. Further, in order to prevent the removal power of the filter medium from being saturated, it is necessary to recover the iron content retained by the filter medium by backwashing or the like, but there is room for improvement in that the burden of this work is large.

[0006]

SUMMARY OF THE INVENTION The present invention has been made in view of such circumstances, and the above-mentioned Japanese Patent Application No. 4-2849.
The purpose is to improve the technology in No. 18, especially to improve the removal rate of the precipitated iron from water, which is a factor of increasing the size of the apparatus structure, and to improve the recoverability of the precipitated iron removed from the water.

[0007]

To this end, in the present invention, a filter medium containing a non-hazardous alkaline component such as Ca, Na, K, and Mg that can be eluted is filled. Further, the water to be treated is allowed to pass continuously through the first treatment unit having the air diffuser and the second treatment unit having the magnet, and the water is treated by the first treatment unit which is performing aeration by the air diffuser. Provided is a water treatment method and apparatus in which iron is deposited from target water, and the deposited iron is adsorbed by a magnet in a second treatment section to be removed from water.

In this water treatment method and apparatus, as the first step, similar to the technique of Japanese Patent Application No. 4-284918,
The iron content dissolved in water in the state of ferrous hydroxide [Fe (OH) ₂ ] is changed to insoluble ferric hydroxide [Fe (OH) ₃ ]. This change is promoted by the contact of the water to be treated with the filter medium containing the alkali component that can be eluted in the first treatment section and the aeration by the aeration means. That is, the alkali content from the filter medium is efficiently eluted by being promoted by the presence of oxygen supplied by aeration, and the above-mentioned change rapidly progresses due to the eluted alkali content. Then, as the second stage,
The iron component deposited as ferric hydroxide [Fe (OH) ₃ ] is removed from the water by forcibly adsorbing it to the magnet by its magnetic force.

Therefore, in this water treatment device, the precipitated iron component can be removed from water with much higher efficiency than the removal by the filter medium, and as a result, the treatment amount per unit time can be increased with a compact device structure. . The iron adsorbed by the magnet can be easily recovered by scraping it off. Therefore, the recoverability can be greatly improved.

As the magnet used in the present water treatment apparatus, either a permanent magnet or an electromagnet can be used, but in terms of workability of recovering the adsorbed iron component, it is particularly preferable to use an electromagnet whose magnetic force can be adjusted. preferable.

[0011]

Embodiments of the present invention will be described below. The first embodiment is an example of a water treatment device suitable for treating natural running water such as river water. This is schematically shown in FIG. As can be seen in FIG. 1, a first processing section 1 and a second processing section 2 each of which is divided into a box shape by a concrete wall or the like.
It has a structure in which are arranged side by side in the horizontal direction. Further, the water to be treated, whose flow is indicated by an arrow, is supplied to the first treatment unit 1 from the upper side, and this flows down the first treatment unit 1 to the second side from the bottom side.
It flows into the processing section 2, then rises in the second processing section 2 and flows out from the upper side thereof.

In the first treatment section 1, Ca that can be dissolved in water is used.
It is filled with a mineral-based filter medium 3 containing a large amount of components. An air diffuser 4 is provided at the bottom of the first processing unit 1 as an air diffuser. The air diffuser 4 is also extended to the bottom of the second processing section 2 so that air supplied from a blower (not shown) at a predetermined pressure is ejected to both processing sections.

The second processing section 2 is provided with a plurality of electromagnets 5, 5, ... Having a proper size arranged in a predetermined array pattern. These electromagnets 5 are connected to a power source 6,
Generates a predetermined magnetic force when activated.

FIG. 2 shows a water treatment apparatus according to the second embodiment, which has a structure suitable for treating spring water at a construction site. Specifically, the whole is formed in a tank shape, and the inside is partitioned by the partition wall 11,
One of them is the first processing unit 12, the other is the second processing unit 13, and the lower side of these two processing units is the communication unit 14. Also in this case, as in the first embodiment, the water to be treated is supplied to the first treatment section 12 from the upper side, and
The structure is such that the processing section 12 flows down, flows into the second processing section 13 from the bottom side through the communication section 14, and then the second processing section 13 rises and flows out from the upper side.

The first processing section 12 is filled with the same filter medium 3 as in the first embodiment, and the second processing section 13 is provided with an electromagnet 15 connected to the power source 6 in the same manner as in the first embodiment. It is arranged. The electromagnet 15 is also arranged in the communication section 14, and therefore the communication section 14 also functions according to the second processing section 13. Further, both of the processing units 12 and 13 are provided with an air diffuser 16 common to the bottoms thereof in the same manner as in the first embodiment.

[0016]

As described above, the water treatment method and apparatus according to the present invention can be completed with a compact apparatus structure even if the treatment amount per unit time is large, and the recoverability of iron removed from water can be achieved. Can be greatly improved.

[Brief description of drawings]

FIG. 1 is a configuration diagram of a water treatment device according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram of a water treatment device according to a second embodiment of the present invention.

[Explanation of symbols]

 1, 12 1st treatment part 2, 13 2nd treatment part 3 Filter media 4, 16 Air diffuser 5, 15 Magnet

Claims (2)

[Claims] 1. A water treatment method for removing iron from iron-containing water, which comprises a first treatment part filled with a filter medium containing an elutable alkaline component and having an aeration means, and a second treatment having a magnet. Parts are continuously provided, and iron is precipitated from the water to be treated by passing through the first treatment part while performing aeration with a diffuser, and the precipitated iron component is adsorbed to the magnet in the second treatment part. A water treatment method characterized by: 2. A water treatment device for removing iron from iron-containing water, comprising a first treatment part filled with a filter medium containing an elutable alkaline component and having an aeration means, and a second treatment having a magnet. And an aeration means for performing aeration by passing through the first treatment section to precipitate iron from the water to be treated, and the precipitated iron is adsorbed to the magnet in the second treatment section. Water treatment device characterized by: