JPS6049007B2 - filtration material - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a filter material, and particularly to a filter material suitable for use in a pond water purifier.

Conventionally, sponges, granular zeolites, and the like have been used as filter materials for this type of pond water purifier. However, since these have large voids, it has been difficult to capture algae (the size of which is about 10 μm) that grows rapidly in the summer.

As a result, pond water becomes cloudy green and its visibility decreases, making it difficult to view fish and other fish, which has been a source of trouble for pond water enthusiasts.
For example, installing a large-scale sand filter tank to purify the pond water can solve this problem, but it is costly and difficult to clean when the filter sand becomes clogged. Therefore, there has been a strong demand for the development of a filter material that is easy to handle and maintain, and is capable of trapping and separating algae.

As a means to deal with this, the present applicant has previously developed a new filter material as disclosed in Patent Application No. 1286 of 1978.

This filter material is made by mixing and molding a filter aid, an adsorbent, and a fiber, and examples of its components include:
These are diatomaceous earth, zeolite and bulb.

However, the characteristics of this filter material are that algae can be filtered and separated at low operating pressure, and that ammonia nitrogen and organic matter can also be removed using an adsorbent.

However, since the filter material consists of powder and valves, its mechanical strength is not sufficient, and LN (Lin
When earVelOcity) was set high, the filter medium was sometimes damaged.

One way to improve the strength of this filtration material is to apply adhesive, but this may clog the pores in the filtration material, increasing filtration resistance, or the surface of the adsorbent (such as zeolite) may become adhesive. However, there are some drawbacks such as reduced adsorption performance due to being covered with agents, and the original characteristics of the developed filtration media have not yet been fully utilized. The present invention
In view of the above points, the object is to employ a reinforcing agent that can improve the strength without impairing filtration resistance or adsorption ability, and to provide a filtration material obtained thereby.

A feature of the present invention is a filter material composed of a filter aid, an adsorbent, and a valve, in which a colloidal reinforcing agent is added and heated to improve mechanical strength.

In short, the present invention incorporates a reinforcing agent (such as silica sol and alumina sol!) as a means to overcome the lack of strength of the pond water purifier filtration material developed above.

Regarding one embodiment of the present invention, referring to the drawings, next,
Explain in detail.

First, to provide a supplementary explanation of the filter material according to Patent Application No. 12861 filed in 1978, which was developed by the present applicant, as its constituent components are a powder and a valve, mechanical Although it was not strong enough, it has excellent ability to capture suspended particles and adsorb soluble nitrogen compounds, and at the same time, it has the characteristics of being able to perform filtration treatment at low operating pressure4. , without sacrificing these advantages,
A method to improve mechanical strength has been desired.

That is, FIG. 1 shows the tensile strength of the filter material developed above, and its components are diatomaceous earth and valve. Here, tensile strength is calculated by dividing the tensile load when cutting the filter material by the cross-sectional area of the filter material, and as shown in the figure, the tensile strength increases as the valve content increases. I understand that.

This is because the fiber entanglement of the bulb increases. However, considering the SS concentration of the permeated water in Figure 2, which shows the relationship between the SS concentration of the permeated water and the content of the bulb, if the content of the bulb is increased, the pores of the filter medium will be enlarged, resulting in clearer Improving the strength of the filter medium by increasing the content of paper bulbs cannot be said to be an optimal method, since no permeated water can be obtained. In addition, the content of the valve in the filter material suitable for pond water purification must be kept to 70% or less from the viewpoint of the SS concentration (10 ppm) of the permeated water, and a significant improvement in tensile strength cannot be expected.

In addition, in the above, the SS concentration is referred to as ゛SL]S
The suspended solids concentration refers to the suspended solids concentration, and as shown in Figure 2, the filter material components are diatomaceous earth and a valve, and the SS concentration in the raw water is 126 ppm. The filtration pressure was constant at 0.26 k9/d, and the thickness of the filter material was 3 wm.

Therefore, in one embodiment of the present invention, the application of silica sol was studied and adopted.

That is, the silica sol referred to here is a hydrophilic sol in which fine particles of silica (silicon) are dispersed in water.

The fine particles have a size of 1 to 100 μm and are stabilized in water. This sol mixes well when added to the mixture of filter media materials in the embodiments of the present invention, that is, bulbs, zeolite, and diatomaceous earth as a filter aid. As an example, per 1 d of filter material area, 200 y of bulbs, 100 y of zeolite, 5 diatomaceous earth
24 silica sol consisting of 20% SlO2 was added to 00y.
Add 0ml and mix well with appropriate amount of water.

After molding this to a thickness of 2Tfr1n, it is dried to complete a filter medium.

The chart in FIG. 3 shows the results when the drying conditions were changed in this case.

That is, as shown in FIG. 3A, the predetermined upper limit is The heating means using the heating conditions of rapid heating 1, which maintains the heating temperature after reaching the heating temperature of around 150°C, is the most excellent, and provides a filter medium with high mechanical strength. In addition, in Figure 3. The numbers indicate the tensile strength under each heating condition of rapid heating 1, stage heating 2, and slow heating 3 described above. Therefore, there are two methods for adding the silica sol: mixing it together with other materials as described above, and impregnating a filter material manufactured without adding silica sol with silica sol afterwards and drying it. There are several methods, which can be adopted depending on your needs.

Next, FIG. 4 is a chart showing the results of an actual pond purification experiment in which this filter material was used to purify pond water in an actual pond.

In the figure, 4 is a pond water purifier, 5 is a pond, the capacity of the pond 5 is 200e (46 goldfish), the treatment method is circulation treatment, and the experiment period is from July to August. As a result, the difference in water quality between using and not using a purifier incorporating this filtration material is remarkable, proving the superiority of this filtration material.

Furthermore, Figure 5 A shows the content of silica sol when silica sol is used as a reinforcing agent for the filter medium.
It shows the change in tensile strength and filtration pressure, and its components are diatomaceous earth, valve, and silica sol, the amount of permeated water is 100e/Mln/7t1, and the raw water is tap water.

In other words, the tensile strength improves as the silica sol content increases, but does not change when the silica sol content exceeds about 50%, and this value reaches about 6 times that of the case where no silica sol is added. be.

Furthermore, the filtration pressure, which indicates the filtration resistance of the filter medium, remains almost unchanged until the silica sol content reaches 50%, but increases rapidly when the silica sol content exceeds 50%. Therefore, it is possible to improve the strength of the filter material without increasing the filtration resistance, and the component ratio of the silica sol at that time is 30 to 40% (dry weight).
is optimal. The next step was an underwater strength test of the filter material, in which a parallel water flow was applied to the surface of the filter material, and the underwater strength of the filter material was evaluated based on the critical flow velocity that would cause damage. That is, the table in FIG. 6 shows the results.

As a result, it was confirmed that the filtration medium containing silica sol had significantly increased failure flow velocity and improved mechanical strength even under water. Finally, FIG. 7 shows the relationship between the silica sol content and the total nitrogen removal rate, and is an investigation of the influence of silica sol on the nitrogen adsorption performance of the filter medium.

The components are zeolite, bulb, and silica sol, and the total nitrogen in the raw water is 25.3 ppm, and the filtration rate is L.
．． V. This is related to 357TL/Hr.

According to this, no decrease in the nitrogen adsorption performance of zeolite was observed due to the addition of silica sol.・However, when the filter material added with silica sol and heated and dried is observed under a microscope,
As schematically shown in FIG. 8, it can be seen that silica is in a crosslinked state between other components and has pores of several microns. This crosslinked state improves the mechanical strength of the filter medium. In addition, in FIG. 8 above, 6 is diatomaceous earth, zeolite, 7 is bulb fiber,
8 is silica sol. Furthermore, since the pores are maintained, the filter material does not lose its ability as a filter material, and there is no problem in removing nitrogen.

That is, by adding silica sol, the mechanical strength of the filter medium can be improved, and suspended matter removal and nitrogen removal can be maintained, which is an ideal result for a filter medium.

In addition, in the above example, silica sol was used as the reinforcing agent, but in addition to this, anorumina sol,
Alternatively, the same properties and effects as above can be obtained by using a mixture of silica sol and alumina sol.

Taking all the points mentioned above into consideration, according to the present invention, 7.
It is possible to obtain an ideal filtering material having excellent multifaceted properties and accompanying exceptional effects, and it can be said to be an outstanding invention in terms of practical effects.

Brief explanation of the drawings Figure 1 is a diagram showing the relationship between the content of valves in the filter medium and tensile strength, Figure 2 is a diagram showing the relationship between the content of valves in the filter medium and the SS concentration of permeated water, and Figure 3 is a diagram showing the relationship between the content of valves in the filter medium and the SS concentration in permeated water.
Figure A and Figure 4 are curve diagrams of each condition of atmospheric temperature and time during drying, including the case according to an embodiment of the present invention, and a table of tensile strength under each heating condition. Table and explanatory diagram of the actual pond purification experiment results according to one example, Figure 5 A,
Figure 6 is a graph showing the relationship between silica sol content, tensile strength, and filtration pressure, also according to one example.
FIG. 7 is a table of the underwater strength test results of the same example, and FIG. 8 is a relationship diagram between the silica sol content and total nitrogen removal rate of the same example. FIG.

6...Diatomaceous earth, zeolite, 7...Bulb fiber, 8...Urikasol.

Claims (1)

[Scope of Claims] 1. A filtration material composed of a filter aid, an adsorbent, and pulp, characterized in that the mechanical strength is improved by adding and heating a colloidal reinforcing agent. 2. The filter material according to claim 1, wherein the colloidal reinforcing agent is silica sol, alumina sol, or a mixture of silica sol and alumina sol. 3. The filter medium according to claim 1, in which the amount of colloidal reinforcing agent added is 20 to 40% of the total weight of the filter medium on a dry weight basis. 4 In claim 1, the heating condition is such that the temperature is maintained after reaching a predetermined upper limit heating temperature,
A filter material having the above-mentioned upper limit heating temperature of around 150°C.