JPH02233196A - Material for decoloring and cleaning of water and its preparation - Google Patents

Abstract

PURPOSE:To obtain a material for decoloring and cleaning of water at high efficiency by heating a gamma-MnO2 under certain conditions after the gamma-MnO2 is treated with an acidic solution. CONSTITUTION:A gamma-MnO2, which is treated with an acidic solution, is heated to give a water cleaning material of the resulting porous molded gamma-MnO2. Even when the material is used in water for a long period, it keeps its shape and high decoloring efficiency. A molded material of active gamma-MnO2 for decoloring and cleaning of water is thus prepared by relatively simple processes.

Description

[Detailed Description of the Invention] [Industrial Field of Application] The present invention relates to a decolorizing water purifying material and a method for producing the same, and more specifically to γ-type dioxide for removing amber components contained in well water, river water, ground water, etc. The present invention relates to a decolorizing water purifying material made of manganese and a method for producing the same.

[Prior Art] In recent years, environmental pollution, particularly water pollution caused by wastewater, has become significant, and natural waters such as well water, river water, and groundwater often turn discolored.

These blue colors include those caused by colloidal fine particles such as iron, manganese, or hardness components, and those caused by humic acid, and various removal devices have been devised.

In Japan, raw water with a chromaticity of 20 degrees or higher according to the water quality standard mulberry under the Water Supply Law is said to exist at approximately 3,400,000 tons/day (Water Supply Statistics I published in 1986), but Commercial water is specified to have a chromaticity of 5 degrees or less, and there is an urgent need to find a way to efficiently convert this raw water into clean water.

Conventionally, common raw water treatment methods include an oxidation method using ozone or an oxidizing agent, a method using activated carbon, a contact filtration method, and a coagulation sedimentation method.

However, these methods have the following problems. That is, the oxidation method is expensive, and there is a risk of air pollution due to the processing agent used. In the method using activated carbon, activated carbon has a low suction ability for the manganese and iron contents ('7-■) in raw water, and also does not have a high ability to decolorize colored components. For example, zeolite 1, which has manganese dioxide attached to its surface, is expensive, and the adhesion of manganese dioxide is weak, resulting in severe loss and deterioration due to desorption and outflow of manganese dioxide.Also, coagulation-precipitation method So, the more coloring ingredients there are, the more
As the amount of pollution generated increases, large-scale pollution treatment equipment becomes necessary and costs increase.

[Lesson 2l for inventions to solve! ¥i] An object of the present invention is to provide an efficient water decolorizing water purifying material that has relatively few of the above-mentioned problems.

[Means for Solving the Problems] As a result of various studies on water purification materials using manganese dioxide, the inventors of the present invention discovered that by heating γ-manganese dioxide treated with an acidic solution under certain conditions, a material made of γ-manganese dioxide can be produced. They discovered that an efficient water purifying material could be obtained and completed the present invention.

That is, the present invention relates to a decolorizing water purifying material made of shaped γ-type manganese dioxide obtained by kneading γ-type manganese dioxide with an acidic sulfuric acid solution and heating the mixture in a humid atmosphere.

Next, the present invention will be further explained.

It has long been generally accepted that manganese dioxide has the effect of decolorizing rock-colored water, but blocks of electrolytic manganese dioxide that have been simply crushed and processed have a small effective reaction surface area, and they cannot be used as inorganic binders. The problem with molded products is that the active manganese dioxide surface is covered with the binder, resulting in poor decolorizing effect. Also,
It is known that there are three types of crystalline forms of manganese dioxide, and the resolution of humic acid, which is one of the color components of water, is as follows.

7 -MnO > a -MnO ≧β-M n0
2 The present inventors investigated a method for obtaining γ-Mn02 powder in a shape suitable for handling without using a binder, and as a result, discovered the following method.

■) Add an acidic solution to the raw material γ-Mn02 powder and knead it. A method of heating the kneaded material in a humidified state, 2) γ of the raw material
In this method, a predetermined acidic solution is added to MnO* powder, kneaded, granulated in advance (for example, 20 to 42 mesh), and the granulated product is heated in a humidified state.

It has been found that by such a method, molded γ-M n0 2 that is macroscopically bolus, strong, and has an active surface can be obtained.

That is, the present invention heat-treats γ-M nO 2 using an acidic solution to form a bolus shaped γ-M
It is characterized by being a water purifying agent consisting of n 0 2.

γ-M n0 2 used in the present invention is preferably obtained by electrolysis and has a particle size of 200 to 400 mesh. Also, this γ-MnO. is mixed with an acidic solution and kneaded. The acidic solution added during this kneading is preferably a sulfuric acid acidic solution that does not contain other cations such as metal ions (for example, pure water with a specific resistance of ioxto'Ω・C■ or more). The amount used is γ-MnO.

It is 10 to 30 parts by weight per 100 parts by weight, and the concentration of the sulfuric acid acidic solution used is preferably 5 to 10 g/1. In the present invention, the above-mentioned kneaded product is heated as it is, or it is formed into granules or pellets using a conventional method. At this time, by heating in a humidified state, the i゛1 water purifying material is mixed with water. A molded article that does not disintegrate even when touched and used can be obtained. Furthermore, if the above-mentioned kneaded product is simply heated in the atmosphere, the moisture will immediately evaporate, intergranular solidification will not proceed, and the product will only become brittle lumps or granules.

Further, the water purifying material of the present invention is characterized by being made of γ-MnO2 as described above, but by adjusting the heating conditions of the present invention, it is possible to make a strong water purifying material made of such γ-MnO2. I can do it.

The conditions for the above heat treatment are a temperature of 90 to 100 at normal pressure.
℃ and relative humidity of 90% or higher, and the treatment time is from 1 hour to 40 hours. Moreover, if a slight amount of pressure is applied when heating the molded product, the molded product will become even stronger. The pressurizing conditions at this time are 30 to 100 pa.

By such a method, a molded γ-M n0 2 which is macroscopically bolus, strong and surface active is obtained. The water purifying material of the present invention is. , from the X-ray diffraction of this material, approximately 1
00% of γ-Mn02.

[Effects of the Invention] As described above, the present invention maintains its original shape even when used underwater for a long time, and has a high decolorizing effect. Furthermore, a molded decolorizing water purifying material made of active γ-MnO2 can be obtained through a relatively simple process.

[Example] Examples will be described below, but the present invention is not limited thereto.

Example 1 5 kg of 320 mesh electrolytic manganese dioxide was
O410g#! After kneading using the acidic solution 1i, the kneaded product was heat-treated at 100° C. for 24 hours under a pressure of 50 KPa while keeping it in a humidified state with a relative humidity of 95% to obtain bulk manganese dioxide. This material was washed with water and then neutralized with caustic soda to obtain a 20-40 mesh water purification cage. i
The X-ray diffraction pattern of the recycled wood is shown in Figure 1.

Example 2 5 kg of 320 mesh electrolytic manganese dioxide was added to 11. S
After kneading with an acidic solution 11 of O4+og/β, the kneaded product was made into granular manganese dioxide of 20 to 40 mesh. This granulated product was heat-treated at 100° C. for 10 hours in a humidified state with a relative humidity of 95% to obtain granular manganese dioxide having the same shape as the raw material. Furthermore, this was washed with water, and then neutralized with caustic soda to obtain a purified water shrine.

The X-ray diffraction pattern of the obtained agent is shown in Figure 2.

Comparative Example 1 5 kg of 320 mesh electrolytic manganese dioxide was
SO lOg#! , I+,, SO410g#! After kneading with acidic solution 11', granulate (20 to 40 mesh)
This granulated product was heated at 100° C. for 72 hours while being kept in a humidified state of +11 to 95% humidity to obtain granular manganese dioxide. This material was washed with water and then neutralized with caustic soda to obtain a water purifying material. The X-ray diffraction pattern of the obtained material showed that it contained α-M n 0 2 .

Comparative Example 2 5 kg of electrolytic manganese dioxide of 32 romesh was added to K S
After kneading with 1 fl of an acidic solution containing 10 g/i of O and 10 g/4 of II2SO4, it was granulated (20 to 40 mesh), and the granulated product was kept in a humidified state with a humidity of 95% and heat-treated at 100°C for 100 hours. , granular manganese dioxide was obtained.

Furthermore, water purification material was obtained by washing with water and then neutralizing with caustic soda. The obtained material contained β-MnO2 from the X-ray diffraction pattern.

Example 3 Example and comparative example. We conducted a performance comparison experiment using the water purifying material obtained by the method.

In the experiment, the column was washed with SV-10 (*) at 7.
This was a water flow test for 7 days, and a comparative evaluation was performed using the treated water after water flow for 7 days.

*SV (Space Velocity) [
l/l+r]: Space velocity, the value obtained by dividing the amount of water passing through the layer per hour by the amount of water purifying material.

However, the amount of chlorine added was 10mg/1.

The results are shown in Table-1. From Table I, it is clear that the decolorizing effect of Example 1.2 is superior to that of Comparative Examples 1 and 2.

[Brief explanation of the drawing]

Figures 1 to 4 In order, Example 1, Example 2, Comparative example 1, Engraving of drawings (no changes to content) X-ray diffraction of the cleaning agent obtained in Comparative Example 2. FIG.

Claims (1)

[Scope of Claims] 1) A decolorizing water purifying material made of molded γ-type manganese dioxide kneaded with an acidic sulfuric acid solution and heated under pressure in a humid atmosphere. 2) A method for producing a decolorizing water purifying material made of γ-type manganese dioxide, which comprises kneading γ-type manganese dioxide with an acidic sulfuric acid solution, heating and molding the mixture in a humidified atmosphere. 3) The manufacturing method according to claim 2), wherein the granulated product is kneaded with an acidic sulfuric acid solution and heated in a humid atmosphere.