JPH0122037B2 - - Google Patents

Description

[Detailed description of the invention]

(Field of the Invention) The present invention relates to a filter medium for water purification, and more specifically, a filter medium for water purification that removes undesirable components such as manganese, iron, and coloring components contained in lake water, river water, underground water, etc.
The present invention relates to a water purification filter material made of macroscopically porous and surface-active granular manganese dioxide containing manganese dioxide alone or a mixture of β-type manganese dioxide and γ-type manganese dioxide. (Background of the Invention) In recent years, lake water, rivers, etc. have been significantly contaminated, and an increasing number of water sources are unsuitable as water supply sources for drinking water. Along with this, purification processing equipment has also become more complex, and processing costs have also increased. Conventionally, methods commonly used to remove manganese, iron, and coloring components from raw water include () oxidation methods using ozone and oxidizing agents;
Treatment methods include () an adsorption method using activated carbon, () a contact filtration method using manganese-impregnated zeolite, () a coagulation sedimentation method using a flocculant, or a combination of these methods. However, each of the conventional removal methods described above has the following problems. First, the oxidation method using ozone or an oxidizing agent increases the cost, and the treatment method using ozone in particular causes the problem of air pollution, so equipment to prevent this is also required. Furthermore, although activated carbon is good in terms of adsorbing other components, it has almost no ability to adsorb manganese and iron, and also has a low ability to adsorb colored components. Next, in the contact filtration method, conventionally, manganese zeolite with manganese dioxide attached to the surface has been mainly used. This is usually produced by immersing zeolite in a solution containing divalent manganese ions and then adding an oxidizing agent such as potassium permanganate to adhere manganese dioxide to the surface of the zeolite. However, this method requires a considerable amount of expensive chemicals such as potassium permanganate, resulting in high processing costs, and if the raw water contains a large amount of manganese, a good removal effect cannot be expected. Furthermore, since the adhesion force of manganese dioxide on the zeolite surface is not so strong, loss and deterioration due to desorption and outflow of manganese dioxide is significant. On the other hand, in the coagulation-sedimentation method, as the amount of colored components increases, the amount of sludge generated increases, and the cost of sludge treatment also increases. (Object of the Invention) The present invention was made to solve these problems, and is a water purification device that efficiently and economically removes manganese, iron, or coloring components from raw water such as lake water, river water, and groundwater. The purpose is to provide filter media. As a result of studies in line with the above objectives, the present inventors have found that by using manganese dioxide having specific properties obtained by a specific method as a filter medium for water purification,
The present invention was developed based on the discovery that this method is extremely effective in removing manganese, iron, coloring components, etc. from water. (Structure of the Invention) That is, the present invention provides γ-type or γ-type manganese dioxide powder with a metal ion selected from the following (a) or (b): copper, zinc, cobalt, nickel, cadmium. , strontium, indium, aluminum, bismuth, tin, chromium, silver, lithium,
at least one ion selected from the group consisting of gallium, thallium, sodium and potassium; (b) manganese ion and/or magnesium ion; and copper, zinc, cobalt, nickel, cadmium, strontium, indium, aluminum, bismuth, At least one kind of ion selected from the group consisting of tin, chromium, silver, lithium, gallium, thallium, sodium, and potassium is kneaded and granulated with an acidic solution containing the following, and the mixture is heated in a humid atmosphere. , or β-type manganese dioxide alone or a mixture of β-type manganese dioxide and γ-type manganese dioxide obtained by further immersing in an acidic solution containing metal ions selected from (a) or (b) above after heating. The water purification filter medium is made of granular manganese dioxide which is macroscopically porous and has an active surface. First, in order to use manganese dioxide as a filter medium, it is necessary to make it an appropriate particle size in order to provide the necessary water flow rate. In order to make manganese dioxide to an appropriate particle size, conventionally, electrolytic manganese dioxide blocks are roughly crushed and sized, or
Alternatively, it is possible to mold manganese dioxide powder using an inorganic binder, such as alumina cement. However, coarsely pulverized electrolytic manganese dioxide blocks have the disadvantage of having a small effective reaction surface area. In addition, products molded using an inorganic binder have a problem in that the water purifying effect is poor because the active manganese dioxide surface is covered with the binder. Therefore, in the water purification filter medium of the present invention, in order to obtain macroscopically porous and surface-active granular manganese dioxide containing β-type manganese dioxide alone or a mixture of β-type manganese dioxide and γ-type manganese dioxide, for example, , the following method is used. First, using manganese dioxide powder as a raw material,
This is granulated by adding a predetermined acidic solution, heat-treated, and formed into manganese dioxide granules. Manganese dioxide powder includes electrolytic manganese dioxide,
Chemical manganese dioxide and natural manganese dioxide, which are said to have a so-called γ-type or mainly γ-type crystal form, are used, and these are kneaded with an acidic solution containing metal ions to obtain the particle size necessary for water purification filter media. For example, granulation is performed to 20 to 42 meshes. By heating this granulated material in a humidified state,
Alternatively, by immersing the material in an acidic solution containing the above metal ions after heating, granular manganese dioxide which is macroscopically porous, strong, and has an active surface can be obtained. Here, the reason why the particles of manganese dioxide powder solidify together due to heat treatment is due to the phenomenon accompanying the transition from γ type to β type, and similar heat treatment is performed using β type manganese dioxide powder. It does not harden even after aging. Therefore, when β-type or mainly β-type manganese dioxide is used as a raw material, granules that do not disintegrate in water cannot be obtained even through the same treatment steps as in the present invention. Next, metal ions, acid, and temperature are important factors for the transition of manganese dioxide from the γ type to the β type, and in the present invention, prior to heat treatment, an acidic solution containing metal ions is added to the granular manganese dioxide. In addition, knead and granulate. As for the metal ions to be made to coexist in the acidic solution used here, in Japanese Patent Application No. 192424/1989, previously filed by the present inventors, an acidic solution containing divalent manganese ions and/or magnesium ions was used. We proposed a method for producing strong manganese dioxide for water purification. As a result of subsequent research, manganese ions and/or
Or in addition to magnesium ion, the above (a) or
It has been found that metal ions selected from (b) can also be used. (a) Copper, zinc, cobalt, nickel, cadmium, strontium, indium, aluminum, bismuth, tin, chromium, silver, lithium,
at least one ion selected from the group consisting of gallium, thallium, sodium and potassium; (b) manganese ion and/or magnesium ion; and copper, zinc, cobalt, nickel, cadmium, strontium, indium, aluminum, bismuth, An acidic solution containing at least one ion selected from the group consisting of tin, chromium, silver, lithium, gallium, thallium, sodium and potassium, and thus a metal ion selected from (a) or (b) above. It has been discovered that it is possible to produce granular manganese dioxide as a filter medium for water purification, which has the same color removal performance as when manganese ions and/or magnesium ions are used. As a result, in manufacturing the water purification filter medium of the present invention, it has become possible to appropriately select easily available metal ions or combinations thereof. During granulation, the amount of the acidic solution added may be the same as the amount normally used for granulation. The higher the concentration of metal ions and acid in an acidic solution, the faster the solidification tends to occur. Next, by heating the above granules in a humidified state, it is possible to obtain granules that do not disintegrate even when placed in water; however, if the granules are simply heated in the air, the water evaporates immediately and β-ization progresses. First, when placed in water, most of the material becomes granular, which disintegrates, and the presence of moisture is extremely important during heat treatment. In addition, the longer the heat treatment time, the stronger the granules become after treatment, and the heat treatment time is usually 1~
3 days is appropriate. In the present invention, by further immersing the heat-treated granular manganese dioxide in an acidic solution containing the above-mentioned metal, the particles in the granular body are bonded to each other, and even stronger granular manganese dioxide can be obtained. The longer the immersion time, the stronger the strength. Even if the immersion time is the same, the strength of the granules will vary depending on the type of metal ion in the acidic solution, but usually about 3 days is sufficient. If the strength of the granules is somewhat weak depending on the type of metal ion, the strength can be further improved by lengthening the immersion time. The higher the temperature of the acidic solution, the better, and preferably 90°C or higher. Next, the granules are washed with water so that the water that has passed through the granules falls within the hydrogen ion concentration (PH) standard, which is one of the water quality standards for tap water, and then a neutralizing agent such as caustic soda is added. Neutralize using Through this neutralization treatment, the PH value of the treated water becomes about 6 to 7 even at the initial stage of water flow, and it can fully satisfy the water quality standard value of 5.8 to 8.6 for tap water. The strength of the granules was measured by the abrasion rate test, which is one of the test items in the water filter sand test method (JWWAA103), and the strength of the granules was 3 to 50% when heated in a humidified state. Those heated in a humidified state and then further immersed in an acidic solution containing metal ions have a concentration of 0.5 to 5%, indicating that the strength is significantly improved by immersion in an acidic metal ion solution. Note that the smaller the abrasion rate, the stronger the sand. The filter medium for water purification according to the present invention is macroporous and forms strong granules by utilizing the properties of manganese dioxide without using a binder that would impair the activity of manganese dioxide. Since many acicular or columnar manganese dioxide crystals are formed on the surface, it is thought that this increases the reaction area on the surface and achieves a large water purification ability due to the fact that it is macroscopically porous. It will be done. In addition, if an oxidizing agent such as chlorine or potassium permanganate is added to the raw water in combination with the filter medium for water purification of the present invention, the color removal ability in particular can be extremely improved. In addition, metal ions used in the manufacture of filter media are completely prevented from adhering to the filter media by thorough washing and neutralization treatment, and these metal ions are not detected in the treated water even during water flow tests. It was not done. (Examples of the Invention) The present invention will be described in more detail below based on Examples, Comparative Examples, Reference Examples, and Experimental Examples, but the present invention is not limited thereto. Example 1 45g of copper ions per electrolytic manganese dioxide powder,
After adding and kneading a sulfuric acid acidic solution containing 50 g of sulfuric acid, granulation was performed to obtain granular manganese dioxide of 20 to 42 meshes. This granulated product was heated at 100° C. for 2 days while being kept in a humidified state to obtain granular manganese dioxide that did not disintegrate even when placed in water. Furthermore, for deoxidation, the material was first washed with water and then neutralized with caustic soda to obtain a filter material for water purification that was macroscopically porous and had needle crystals on the surface. Example 2 An acidic solution having the same composition as that used in Example 1 was added to electrolytic manganese dioxide powder, kneaded, and then granulated to obtain granular manganese dioxide having 20 to 42 meshes. While keeping this granulated material in a humidified state,
By heating at ℃ for 4 days, granular manganese dioxide which does not disintegrate even when placed in water was obtained. Furthermore, for deoxidation, neutralization was carried out in the same manner as in Example 1 to obtain a filter material for water purification that was macroscopically porous and had needle-shaped crystals on the surface. Example 3 The granular manganese dioxide obtained in Example 1 was immersed in an acidic sulfuric acid solution containing 45 g of copper ions and 50 g of sulfuric acid, and left to stand for 3 days while maintaining the temperature of the solution at 90° C. or higher. For deoxidation, water washing and neutralization were performed in the same manner as in Example 1. Electron micrographs of the water purification filter medium thus obtained are shown in FIGS. 1a and 1b. In addition, a is 30
times, b is a magnification of 10,000 times. As shown in FIG. 1, the filter medium for water purification of the present invention was macroscopically porous, and needle-like and columnar crystals grew on the surface, further increasing the reaction surface area. Example 4 The granular manganese dioxide obtained in Example 1 was immersed in an acidic solution containing 20 g of copper ions and 20 g of sulfuric acid, and left to stand for 3 days while maintaining the temperature of the solution at 90°C or higher, followed by desorption. Because of the acid, water washing and neutralization were carried out in the same manner as in Example 1 to obtain a filter material for water purification that was macroscopically porous and had needle-like and columnar crystals. Example 5 Chemical manganese dioxide powder with copper ion 45g/,
A filter medium for water purification which was macroscopically porous and had needle-like and columnar crystals was obtained by the same treatment method as in Example 3 using an acidic solution containing 50 g of sulfuric acid. Example 6 45g of zinc ions/electrolytic manganese dioxide powder
After adding and kneading a sulfuric acid acidic solution containing 50 g of sulfuric acid, granulation was performed to obtain granular manganese dioxide of 20 to 42 meshes. This granulated product was heated at 100°C for 2 days while being kept in a humidified state to obtain granular manganese dioxide that would not disintegrate even when placed in water. Add this to 45g of zinc ions/50g of sulfuric acid/
The temperature of the solution was 90℃.
After allowing the material to stand still for 3 days under the above conditions, it was washed with water and neutralized in the same manner as in Example 1 to deoxidize it, thereby producing a filter material for water purification that is macroscopically porous and has acicular and columnar crystals on its surface. Obtained. Example 7 Using electrolytic manganese dioxide powder as a raw material, the same treatment as in Example 3 was carried out using an acidic solution containing 45 g of cobalt ions and 50 g of sulfuric acid, resulting in a material that was porous macroscopically and had acicular and columnar shapes on the surface. A filter medium for water purification having crystals was obtained. Example 8 Using electrolytic manganese dioxide powder as raw material, manganese ions 20g/, copper ions 25g/, sulfuric acid 50g/
The same treatment as in Example 3 was carried out using an acidic solution containing the following, to obtain a filter medium for water purification that was macroscopically porous and had needle-like and columnar crystals on the surface. Comparative Examples 1 to 3 and Reference Example 1 Conventionally proposed or used filter media () formed by molding γ-type manganese dioxide powder together with alumina cement (Comparative Example 1), () coarsely crushed γ-type electrolytic manganese dioxide block , sized filter medium (Comparative Example 2), () Manganese impregnated zeolite (Comparative Example 3)
were prepared by known methods. Also, the patent application filed in 1983, which was filed earlier by the present inventors,
The acidic solution containing manganese ions proposed in No. 192424 and manganese dioxide powder were kneaded and granulated, heat treated in a humidified state, and then immersed in the acidic solution containing manganese ions to obtain a filter medium ( Reference example 1). Experimental Example 1 The water purification filter media obtained in Examples 1 to 8, the water purification filter media of Comparative Examples 1 to 3 that have been proposed or used in the past, and the water purification filter media of Reference Example 1 proposed in a previous application by the present inventors. We compared the performance of removing chromaticity using filter media for water purification. The test conditions were as follows: 100 c.c. of each filter medium was packed in a column, and raw water whose chromaticity was adjusted to 40 degrees was passed through at a rate of 1000 c.c./Hr. The results are shown in Table 1.

[Table] As shown in Table 1, the water purification ability was highest in Examples 1 to 8 using the water purification filter medium of the present invention and Reference Example 1 proposed in a previous application by the present inventors, followed by manganese The order is Comparative Example 3 using impregnated zeolite, Comparative Example 2 using a filter medium made by coarsely crushing and sizing electrolytic manganese dioxide blocks, and Comparative Example 1 using a filter medium made from electrolytic manganese dioxide powder molded with alumina cement. . Comparative Example 3, which has the best water purification ability among the comparative examples, takes about 3 days to exceed the chromaticity of 5 degrees, which is the water quality standard for tap water, whereas Comparative Example 3, which has the best water purification ability among the examples, takes about 3 days. Even in Example 5, which is inferior, it takes about 5.5 days, and in Example 2, which has the best water purification performance, it takes about 8 days, which shows that the filter medium for water purification of the present invention has significantly superior water purification ability compared to conventional filter media. When the filter medium for water purification according to the present invention is used in combination with an oxidizing agent such as chlorine, the life of the filter medium is dramatically improved, and it is thought that the filter medium has a life span of several years or more. In addition, the PH value of the treatment liquid in Examples 1 to 8 is the PH value of the raw water.
The values were almost the same. Experimental Example 2 A strength test was conducted using the water purification filter media obtained in Examples 1 to 8 and the filter media of Comparative Examples 1 and 3. The test method was conducted according to the abrasion rate test method in the water filter sand test method (JWWAA103). That is, we weighed 50g of filter media, charged it into a steel cylinder, added 5 steel balls with a diameter of 9mm, sealed it, and left it for 1 minute.
It was violently vibrated for 5 minutes at a rate of 250 times. After finishing, it is sieved, the weight (Wg) of the filter medium remaining on the sieve is determined, and the attrition rate is calculated using the following formula. Wear rate (%) = (50-W) x 2 The results are shown in Table 2.

[Table] As is clear from Table 2, Examples 1 and 2 obtained by heat treatment in a humidified state are
In terms of chromaticity removal performance, the performance is superior compared to Examples 3 to 8, but it is somewhat weaker in terms of strength.
The wear rate is also higher than that of Comparative Examples 1 and 3. However, in Examples 3 and 4, which were obtained by further immersing the granular material of Example 1 in an acidic solution containing metal ions, the wear rate was significantly reduced.
It turns out that immersion treatment in an acidic solution containing metal ions is very effective in improving strength. Although the strength of Examples 3 to 8 differs somewhat depending on the type of metal ion, the strength is sufficient to be used as a filter medium for water purification. In addition, Example 5, which used chemical manganese dioxide as a raw material, had a higher wear rate than Example 3, which used electrolytic manganese dioxide as a raw material and underwent the same treatment.
From the viewpoint of strength, electrolytic manganese dioxide is preferable as a raw material. Example 3 When iron tubes of electrolytic manganese dioxide, chemical manganese dioxide, and granular manganese dioxide obtained in Examples 2 to 4 and 7 (filter medium for water purification of the present invention), which are raw materials for the water purification filter medium of the present invention, are used. The X-ray diffraction patterns of are shown in FIGS. 2a to 2f, respectively. γ-type manganese dioxide shows a broad diffraction pattern on the diffraction plane at 2θ=28°, and β-type manganese dioxide shows a broad diffraction pattern at 2θ=28°.
It is characterized by a sharp diffraction pattern appearing on the 36° diffraction surface. Figure 2a, which is the X-ray diffraction pattern of electrolytic manganese dioxide, which is a raw material, shows the γ type, and Figures 2c and 2, which are the X-ray diffraction patterns of the granular manganese dioxide of Example 2 and Example 4. Figure e shows a mixture of β and γ types. Furthermore, it was confirmed that the X-ray diffraction patterns of granular manganese dioxide in Examples 3 and 7, shown in FIGS. 2d and 2f, are of the β type. Although not shown, the manganese dioxide obtained in Example 1 was a mixture of γ-type and β-type, and the manganese dioxide obtained in Examples 5 to 6 and 8 was β-type. In addition, in Figure 2b, which is the X-ray diffraction pattern of chemical manganese dioxide, which is the raw material, an amorphous peak appears at the location of 2θ = 31°, but this is due to the γ and ρ type dioxide. It is said to be manganese. Experimental Example 4 Using the water purification filter material obtained in Example 3 and the manganese-impregnated zeolite used in Comparative Example 3, the performance of manganese and iron removal was compared. Raw water with divalent manganese content adjusted to 5 ppm and iron ion content adjusted to 5 ppm was used, and the measurement method was the same as in Experimental Example 1. Comparing the total amount of water treated until the residual manganese reaches the water quality standard of 0.3 ppm, the amount of water treated using manganese-impregnated zeolite (Comparative Example 3) is about 20, whereas that of the water purifying filter material of the present invention was about 20. (Example 3) had a value of about 360, clearly confirming the superiority of the water purification filter medium of the present invention not only in terms of chromaticity but also in terms of manganese removal performance. Regarding iron, residual manganese is 0.3ppm.
It remained below 0.1ppm until it reached . Note that Examples 1 to 2 and 4 to 8 had almost the same performance as Example 3. In addition to the metal ions used in the above examples, nickel, cadmium, strontium, indium,
When using aluminum, bismuth, tin, chromium, silver, lithium, gallium, thallium, sodium, and potassium ions, or a combination of these ions and manganese ions and/or magnesium ions in an acidic solution It was also confirmed that the chromaticity and ability to remove manganese and iron of the filter media for water purification were almost the same as those of Examples 1 to 8. (Effects of the Invention) As explained above, manganese dioxide powder of the γ type or mainly of the γ type is kneaded and granulated with an acidic solution containing the above metal ions, and the resulting product is heated in a humidified atmosphere. A macroscopically porous and surface-active material containing either β-type manganese dioxide alone or a mixture of β-type manganese dioxide and γ-type manganese dioxide, obtained by heating and then immersing in an acidic solution containing the above metal ions. The water purification filter medium of the present invention, which is made of granular manganese dioxide, has extremely high purification ability and low processing cost for raw water, so it can be used for lake water, marsh water,
It is suitably used as a filter medium for water purification to remove colored content, manganese content, and iron content from river water, underground water, etc.

[Brief explanation of drawings]

Figures 1a and 1b are electron micrographs showing the particle structure of the surface of the water purification filter medium of the present invention obtained in Example 3, in which a shows a magnification of 30x and b shows a magnification of 10,000x, respectively. Figures a to f are graphs showing the X-ray diffraction patterns of electrolytic manganese dioxide, chemical manganese dioxide, and granular manganese dioxide obtained in Examples 2 to 4 and 7, respectively, which are used as raw materials in the present invention.

Claims (1)

[Claims] 1. γ-type or γ-type manganese dioxide powder is mixed with metal ions selected from the following (a) or (b): copper, zinc, cobalt, nickel, cadmium, strontium, Indium, aluminum, bismuth, tin, chromium, silver, lithium,
at least one ion selected from the group consisting of gallium, thallium, sodium and potassium; (b) manganese ion and/or magnesium ion; and copper, zinc, cobalt, nickel, cadmium, strontium, indium, aluminum, bismuth, obtained by kneading and granulating with an acidic solution containing at least one ion selected from the group consisting of tin, chromium, silver, lithium, gallium, thallium, sodium, and potassium, and heating this in a humid atmosphere. A filter material for water purification characterized by being made of macroscopically porous and surface-active granular manganese dioxide containing β-type manganese dioxide alone or a mixture of β-type manganese dioxide and γ-type manganese dioxide. 2 γ-type or γ-type manganese dioxide powder is mixed with metal ions selected from the following (a) or (b): copper, zinc, cobalt, nickel, cadmium, strontium, indium, aluminum, bismuth, tin, chromium, silver, lithium,
at least one ion selected from the group consisting of gallium, thallium, sodium and potassium; (b) manganese ion and/or magnesium ion; and copper, zinc, cobalt, nickel, cadmium, strontium, indium, aluminum, bismuth, At least one ion selected from the group consisting of tin, chromium, silver, lithium, gallium, thallium, sodium, and potassium is kneaded and granulated with an acidic solution, heated in a humid atmosphere, and then Macroscopically porous β-type manganese dioxide alone or a mixture of β-type manganese dioxide and γ-type manganese dioxide obtained by further immersion in an acidic solution containing metal ions selected from (a) or (b). , and the surface thereof is made of active granular manganese dioxide.