JPS5843158B2 - Mizushiyorihou - Google Patents

Description

[Detailed description of the invention] The present invention relates to water treatment methods.

More specifically, magnetically sensitive adsorbent substances, biologically treated substances such as activated sludge, flocculants, ion exchange resins, chelate resins, alumina, silica gel, clay minerals, or bauxite (hereinafter these will be conveniently combined with other water (abbreviated as treated water) coexists in one system to treat the water to be treated,
This paper relates to water treatment methods that simplify the water treatment process and improve its economic efficiency.

The term "magnetically sensitive adsorptive material" herein is a general term for magnetically sensitive activated carbon and magnetically sensitive carbide-like substances having cation exchange ability, and magnetically sensitive activated carbon was previously invented by the present inventors and patent application No. 50-86004 (Special Publication No. 58-28203)
□ Magnetically sensitive activated carbon composition, which is thought to have a ferromagnetic material dispersed and supported very evenly on activated carbon, for which a patent application has been filed as □ Magnetically sensitive carbide that has cation exchange ability A ferromagnetic material is a type of intermediate material during the production of shrinkable activated carbon, and is a type of material in which a ferromagnetic material is very evenly dispersed and supported on a carbide-like material that has cation exchange ability. By activating it, it becomes magnetically sensitive activated carbon.

Today's water treatment methods generally include primary treatment using sedimentation tanks, secondary treatment using biological treatment such as activated sludge, or coagulation sedimentation treatment using flocculants, activated carbon, ion exchange resins, or chelate resins. It is considered to be broadly divided into tertiary processing that uses processing.

Conventionally, as a combination of secondary treatment and tertiary treatment or a combination of two different types of tertiary treatment, for example, water treatment has been carried out by combining treatment with activated sludge and treatment with activated carbon, or treatment with a flocculant, It is known to treat water by combining treatment with an ion exchange resin or treatment with a chelate resin and treatment with activated carbon.

This type of combined treatment uses activated sludge,
This method uses activated carbon to adsorb and remove substances that cannot be removed by treatment with a flocculant, ion exchange resin, or chelate resin, and is a preferred method because the water to be treated is further purified.

However, in conventional combined treatments using activated carbon and other water treatment products, the treatment with activated carbon and the treatment with other water treatment products are generally performed as separate processes in separate tanks or equipment. There is.

Such conventional methods have disadvantages in that the process is complicated and the equipment used is expensive.

Conventionally, treatment with activated carbon and treatment with other water treatment products are performed in separate processes.When activated carbon and other water treatment products are mixed and used in one system, only the activated carbon is separated from the system. The main reason for this is that it is difficult to recover, and in order to use activated carbon economically and effectively, it is essential to separate and recover activated carbon, regenerate it, and recycle it.

The present invention aims to simplify the water treatment process, improve its efficiency, and ultimately improve its economic efficiency.The present invention aims to simplify the water treatment process, improve its efficiency, and ultimately improve its economic efficiency. A water treatment method in which treatment with activated carbon and treatment with other water treatment products can be performed in one step in one system, and activated carbon can be easily separated and recovered from the water treatment system. It provides:

The present invention utilizes magnetically sensitive activated carbon as the activated carbon,
Water to be treated can be treated in the coexistence of magnetically sensitive activated carbon and other water treatment products, in which case the generally accepted water treatment effects of other water treatment products will not be impaired, and the The adsorption capacity (ability to remove substances contained in water to be treated) is not impaired, and only the magnetically sensitive activated carbon can be easily separated and recovered from the water treatment system using magnetism, and furthermore, the magnetically sensitive activated carbon can be used together with or in place of the magnetically sensitive activated carbon. If a magnetically sensitive carbide-like material with cation exchange ability is used, cations can be removed by the carbide-like material, and the carbide-like material can also be easily separated and recovered from within the water treatment system using magnetism. This was completed based on the knowledge of the present inventors, such as what is possible.

That is, the gist of the present invention is to provide at least one magnetically sensitive adsorptive substance selected from magnetically sensitive activated carbon and magnetically sensitive carbide-like substances having cation exchange ability, a biologically treated product, a flocculant, an ion exchange resin, Treatment of water to be treated with the magnetically sensitive adsorptive substance and the water treatment product in one system, by coexisting at least one type of water treatment product selected from chelate resin, alumina, silica gel, clay minerals, and bauxite. The present invention relates to a water treatment method characterized in that a magnetically sensitive adsorptive material obtained by treating water to be treated is recovered using magnetism.

Among the magnetically sensitive adsorptive substances used in the present invention, magnetically sensitive activated carbon is used in the above-mentioned Japanese Patent Application No. 50-86004 (
The magnetically sensitive activated carbon described in Japanese Patent Publication No. 58-28203 (Japanese Patent Publication No. 58-28203) can be used, and these can be used in the production of ordinary activated carbon in which carbon-containing substances are fired and activated, with or without pretreatment as required. , carbon-containing substances and/or
Alternatively, it can be obtained by adding and mixing at least one compound containing an iron group metal and an iron group element to the carbon-containing material after the pretreatment when the pretreatment is performed.

The manufacturing method of magnetically sensitive activated carbon itself is outside the scope of the present invention and is described in detail in the above-mentioned Japanese Patent Application No. 50-86004 (Japanese Patent Publication No. 58-28203). Grass coal, lignite, brown coal, bituminous coal, anthracite, semi-formed coke, coconut shell,
Bone powder, wood powder, charcoal, activated carbon, rubber tires, vinyl chloride resin, and other carbon-containing substances are combined with metal powders of iron, cobalt, or nickel, or compounds containing these elements, such as red mud, iron sulfide, iron oxide, iron sand, magnetite, Powders such as magnetite, hematite, or blast furnace dust (hereinafter referred to as magnetic sensitizing substances) are added and mixed, and then molded into a desired shape as necessary or not molded, according to a normal activated carbon manufacturing method. It can be produced by firing and activating the mixture.

At this time, the carbon-containing material may be pretreated, if necessary, thermally or with a sulfonating agent, such as sulfuric acid, oleum, sulfuric anhydride, or chlorosulfonic acid, before or after the addition of the magnetism-imparting substance.

Another method is to add and mix a magnetically sensitizing substance to a carbon-containing substance such as heavy petroleum oil, asphalt, asphalt pitch, coal tar pitch, or sulfuric acid sludge, and then add and mix the sulfonating agent or sulfur or by first adding and reacting a sulfonating agent or sulfur to such a carbon-containing substance and performing an infusibility pretreatment to make it react, and then imparting magnetic sensitivity to the infusible pretreated product. It can also be produced by adding and mixing substances, then molding into a desired shape as necessary, or firing and activating without molding.

In the pretreatment with the sulfonating agent or sulfur, the treatment can be carried out more smoothly by using an organic reaction medium if necessary.

Furthermore, although firing and activation can be performed in separate steps, they may also be performed in one step.

Further, activation is preferably carried out by steam activation, and after activation, it is preferable to cool the activated carbon product in a neutral or reducing atmosphere, for example in steam, until the surface of the activated carbon product becomes 200° C. or lower.

Although the detailed structure and composition of the magnetically sensitive activated carbon thus obtained are not clear, it is considered to be a composition in which a ferromagnetic material is very evenly dispersed and supported on the activated carbon.

In addition, the magnetically sensitive carbide-like substance having cation exchange ability is a type of intermediate substance during the production of the magnetically sensitive activated carbon described above, and is produced by adding a sulfonating agent to a mixture of a carbon-containing substance and a substance imparting magnetic properties. A sulfonating agent is added to a carbide-like material or a carbon-containing material obtained by reacting, molding it into a desired shape if necessary, and/or firing it to the extent that ion exchange ability is not lost. It is possible to use a carbide-like material obtained by adding and mixing a magnetism-imparting substance, preferably molding it into a desired shape, and then firing it to an extent that the ion exchange ability is not lost.

These carbide-like substances are magnetically sensitive substances that have cation exchange ability, but have poor or almost no adsorption ability for organic substances, and can be turned into magnetically sensitive activated carbon with excellent adsorption ability by activation. Although its detailed structure and composition are not clear, it is thought that the ferromagnetic material is very evenly dispersed and supported on a carbide-like material with ion exchange ability.

The magnetically sensitive activated carbon and the magnetically sensitive carbide-like substance having cation exchange ability may be used alone or in combination as required.

In the present invention, other water-treated products that coexist with the magnetically-sensitive adsorptive substance include biological water-treated products such as activated sludge or sludge containing anaerobic microorganisms, light bread, aluminum sulfate, sodium aluminate, iron sulfate, Inorganic or organic flocculants such as chlorinated green bread, slaked lime, sodium alginate, polyethyleneimine, sodium polyacrylate, ion exchange resins, chelate resins (@adsorption resins), alumina, silica gel, clay minerals or bauxite. Water treated products commonly used for water treatment can be used.

In addition, when using a flocculant, it is also possible to use a flocculation accelerator such as kaolin, bentonite, etc., which is generally used in water treatment by the flocculation-sedimentation method, and these combinations are also within the scope of the present invention. It goes without saying that it belongs.

In addition, a plurality of other water-treated products such as those mentioned above can be used at the same time if necessary.

The amount or ratio of the above-mentioned magnetically-sensitive adsorptive substances and other water treatment substances to be used is arbitrary, including the type and content of the substances to be removed in the water to be treated, the purpose of purification and degree of purification of the water to be treated, etc. It may be determined as necessary.

In carrying out the present invention, the magnetically sensitive adsorptive material and the other water treatment product are made to coexist, and the water to be treated is mixed with the magnetically sensitive adsorptive material and the other water treatment material in one system using a conventional method. All you have to do is bring it into contact and treat it.

In this case, the magnetically sensitive adsorptive substance and other water-treated substances may coexist in any state, such as a mixed state, an unmixed state forming a layer, or an intermediate state between these. .

That is, the present invention is directed to the use of known biological treatment methods, coagulation-sedimentation methods, treatment methods using ion exchange resins, chelate resins, etc., in which a magnetically sensitive adsorptive substance coexists with the water treated products of these treatment methods. It can be carried out by

After treatment of the water to be treated, magnetically sensitive adsorptive substances can be easily separated and recovered from the water treatment system using magnetism, that is, a magnetic device.

Regarding the magnetism used for this separation and collection, it is desirable to consider the magnetic flux density depending on the size of the particles of the magnetically sensitive adsorptive substance, the content of ferromagnetic material therein, and the like.

For example, in the case of a magnetically sensitive adsorbent material that contains 6% by weight of ferromagnetic material as pure iron and has a particle size of 0.5 to 3 degrees φ, the magnetically sensitive adsorbent material has a magnetic flux density of 300 Gauss or less. Although the substance cannot be sufficiently separated and recovered, if the magnetic flux density is 400 Gauss or more, the magnetically sensitive adsorptive substance can be sufficiently separated and recovered, and the recovery rate is 99% by weight or more.

Further, as the device having magnetism, for example, a magnetic separation device such as a magnetic drum or a magnetic belt can be used.

Separation and recovery of magnetically sensitive adsorptive substances can be carried out in various ways using these magnetic separation devices.

For example, in a treatment tank where a flocculant or activated sludge coexists with a magnetically sensitive adsorptive substance, the water to be treated is stirred, agitated, and aerated, and the treated water contains magnetically sensitive substances. If adsorbent substances and aggregates or activated sludge are suspended, the treated water should be passed through a channel such as a ditch or pipe, and if necessary, a channel equipped with a pump. The water to be treated is introduced into the magnetic drum via the magnetic drum, and the treated water is passed through the magnetic drum.

In this way, the magnetically sensitive adsorptive substance is selectively captured and recovered from the suspended matter in the water to be treated after treatment in the magnetic drum.

In another embodiment, a magnetic belt is installed directly in the processing tank,
It is also possible to capture and recover only the magnetically sensitive adsorptive substance from the water to be treated after the above treatment using the magnetic belt.

At this time, only the magnetically sensitive adsorptive material is captured from the suspended matter containing the magnetically sensitive adsorptive material in the water to be treated using a magnetic belt that continues stirring, agitation, and aeration even after the treatment.
It is also possible to recover the sludge (containing the magnetically sensitive adsorbent) generated at the bottom of the treatment tank by temporarily stopping stirring or stirring and aeration after treatment, and allowing the suspension containing the magnetically sensitive adsorbent to settle. It is also possible to capture and recover only the magnetically sensitive adsorptive substances from the slurry.

In addition, as a modification of this embodiment, the water to be treated after treatment is guided from the treatment tank to another tank, for example, a sedimentation tank, and a magnetic belt is installed in this other tank, and the magnetically sensitive adsorbent material is removed in the same manner as described above. It is also possible to capture and collect only.

In such a case, when the magnetic belt captures the magnetically sensitive adsorptive material, the suspended matter or sediment other than the captured magnetically sensitive adsorptive material will be removed from the surface of the water to be treated after the magnetic belt has processed it. While rising to the top, it falls back into the water to be treated, and only the magnetically sensitive adsorptive material is separated and recovered.

Note that these aspects can be adopted as necessary, not only when a flocculant or activated sludge is used in combination, but also when other water treatment products other than these are used in combination with a magnetically sensitive adsorptive substance. Needless to say.

In a further embodiment, for example, a magnetically sensitive adsorptive substance and an ion exchange resin or other adsorbent are packed in a packed tower as a mixture or in layers, and the water to be treated is passed through the packed tower. If such treatment is being carried out, after the treatment of the water to be treated, the packed material is extracted from the packed tower, and only the magnetically sensitive adsorbent material is captured from the packed material using a magnetic belt or magnetic drum. It can be recovered.

The magnetically sensitive adsorptive material thus recovered after treatment of the water to be treated is processed using the normal activated carbon regeneration method, i.e. 800 to 900
It can be regenerated into magnetically sensitive activated carbon with excellent adsorption ability by contacting it with water vapor at ℃.

When the magnetically sensitive adsorptive material to be regenerated contains or consists of a magnetically sensitive carbide-like material having cation exchange ability, this magnetically sensitive carbide-like material having cation exchange ability is similar to that of ordinary activated carbon. It is converted into magnetically sensitive activated carbon by a regeneration method, ie, by this regeneration step.

During this regeneration, it is desirable to cool the magnetically sensitive activated carbon in a neutral or reducing atmosphere until the surface temperature of the regenerated activated carbon becomes 200° C. or less.

The regenerated magnetically sensitive activated carbon can be reused in the method of the present invention by adding a magnetically sensitive carbide-like substance having cation exchange ability if necessary.

Furthermore, for example, in the case where the recovered magnetically sensitive adsorptive material is composed of a magnetically sensitive carbide-like material having cation exchange ability, it can be regenerated by a normal cation exchanger regeneration method, for example, by washing with an acid, It can also be reused in the method of the invention.

In the present invention, other water-treated products used in combination with the magnetically sensitive adsorptive substance can also be recovered by a normal method suitable for each case after collecting the magnetically sensitive adsorptive substance, and if necessary, by a normal method suitable for each case. can be recycled and reused in the present invention.

Further, aggregates and the like generated when a flocculant is used may be treated by a conventional method.

According to the present invention, treatment with a magnetically sensitive adsorptive substance and other water treatment products can be performed simultaneously in one system,
In addition, the magnetically sensitive adsorptive substance can be easily isolated from the water treatment system and used effectively, thereby simplifying the water treatment process, improving its efficiency, and ultimately improving its economic efficiency.

For example, it is not necessary to perform treatment with activated carbon and treatment with other water treatment products in two steps as in conventional methods;
This can be carried out in the process, for example, by using water treatment equipment using conventional activated sludge, flocculants, or ion exchange resins, and by using magnetically sensitive adsorptive substances together with each of these water treatment products. There is also the advantage that the invention can be put into practice, and the cost of equipment for water treatment can be reduced.

EXAMPLES Hereinafter, the present invention will be further explained with reference to Examples, but the present invention is not limited to these Examples.

Example l Contains 6% by weight of ferromagnetic material as pure iron and has a particle size of 0.5
General domestic wastewater was treated by combining granular magnetically sensitive activated carbon between 3 and 3 with an activated sludge method known as an aerobic treatment method among biological treatment methods.

That is, TOC is 55 ppm, BOD is 105
The above magnetically sensitive activated carbon was added to 300 ppm of raw domestic wastewater.
ppm and activated sludge were added at 10% by volume, the domestic wastewater was treated for 6 hours while aerating the inside of the tank, and then the treated water was passed through a pipe into a magnetic drum (diameter: 140 gauss) with a magnetic flux density of 1000 gauss. Magnetically sensitive activated carbon was captured, separated, and recovered by feeding the activated carbon at a rate of 10 tons per minute.

The recovery rate of magnetically sensitive activated carbon was 99.6% by weight.

In addition, the TOC of the treated water after treatment is 4 ppm, B
OD was 10 ppn.

For comparison, when the above domestic wastewater was treated using only the above magnetically sensitive activated carbon at 300 ppm, the TOC of the treated water after treatment was 13 ppm.

The BOD was 20 ppm, and when activated sludge was used alone at 10% by volume for treatment, the TOC of the treated water after treatment was 7 pP and the BOD was 16 ppm.

From this fact, it is clear that the treatment effects of both magnetically sensitive activated carbon and activated sludge are obtained in the above examples.

Example 2 Contains 10% by weight of ferromagnetic material as pure iron and has a particle size of 0.
Granular magnetically sensitive activated carbon of 5 to 311 tons was combined with an activated sludge method to treat phenol-containing factory wastewater.

That is, COD is 500 ppm, BOD is 220
500 ppm of the magnetically sensitive activated carbon was added to phenol-containing factory wastewater with a phenol concentration of 136 ppm.
The factory wastewater was treated for 5 hours by adding 20% by volume of PM and activated sludge while aerating the inside of the tank, and then a magnetic belt (belt width 150 mm ) was driven at a speed of 4 m/min to capture, separate, and recover magnetically sensitive activated carbon from the bottom of the tank.

The recovery rate of magnetically sensitive activated carbon was 99.6% by weight.

In addition, the COD of the treated water after treatment is 5 ppm, and the BOD is 2.
The ppm1 residual phenol concentration was 0.

For comparison, when the above factory wastewater was treated using only the above magnetically sensitive activated carbon at 500 ppm, the COD of the treated water after treatment was 10 ppm.

BOD is 7ppm, residual phenol concentration is 10ppm
When activated sludge was used alone at 20% by volume, the COD of the treated water after treatment was 12 p.
pm, B OD is 6 ppm, residual phenol concentration is 8
It was ppm.

From this fact, it is clear that the treatment effects of both magnetically sensitive activated carbon and activated sludge are obtained in the above examples.

Example 3 Contains 10% by weight of ferromagnetic material as pure iron and has a particle size of 0.
Granular magnetically sensitive activated carbon of 5 to 3 liters was combined with a flocculation sedimentation method to treat papermaking white water.

That is, 500 ppm of the magnetically sensitive activated carbon and 15 ppm of slaked lime were added to the raw paper white water with a COD of 60 ppm.
, 30 ppm of light bread, and 2 ppm of sodium alginate were added, and the mixture was treated with stirring for 2 hours, after which it was passed through a pipe into a magnetic drum (diameter 1
The magnetically sensitive activated carbon was captured, separated, and recovered by feeding the activated carbon at a rate of 4 tons per minute.

The recovery rate of magnetically sensitive activated carbon was 99.6% by weight.

The COD of the water to be treated after treatment was 5 pP.

For comparison, when the above papermaking white water was treated using only the above magnetically sensitive activated carbon in the same amount as above, the COD of the treated water after treatment was 35 ppm, and the above 3.
When the treatment was carried out using only the same type of flocculant in the same amount as above, the COD of the treated water after treatment was 30 pP.

From this fact, it is clear that the treatment effects of both the magnetically sensitive activated carbon and the flocculant were obtained in the above examples.

Example 4 Contains 10% by weight of ferromagnetic material as pure iron and has a particle size of 0.
Granular magnetically sensitive activated carbon of 5 to 3 mm in size was combined with an ion exchange method to treat plating wastewater in the automobile manufacturing process.

That is, to the plating wastewater having a chromium concentration of 35 ppm and a cyanide concentration of 11 ppm, 500 ppm of the magnetically sensitive activated carbon and 11,000 ppm of a strong basic anion exchange resin were added, and the mixture was treated with stirring for 1 hour. The magnetically sensitive activated carbon was captured, separated, and recovered by supplying it at a rate of 4 tons per minute to a magnetic drum (diameter: 140 mm, width: 150 mm) with a magnetic flux density of 1000 Gauss via the rear pipe.

The recovery rate of magnetically sensitive activated carbon was 99.6% by weight.

Neither chromium nor cyanide was found in the treated water after treatment.

For comparison, when the plating wastewater was treated using only the magnetically sensitive activated carbon at 500 ppm,
The removal of chromium was incomplete, and when the above ion exchange resin was used alone at 11,000 pp,
Cyan removal was incomplete.

From this fact, it is clear that the treatment effects of both the magnetically sensitive activated carbon and the strongly basic anion exchange resin were obtained in the above examples.

Claims (1)

[Claims] 1 At least one magnetically sensitive adsorptive substance selected from magnetically sensitive activated carbon and magnetically sensitive carbide-like substances having cation exchange ability, a biologically treated product, a flocculant, an ion exchange resin,
Treatment of water to be treated with the magnetically sensitive adsorptive substance and the water treatment product in one system, by coexisting at least one type of water treatment product selected from chelate resin, alumina, silica gel, clay minerals, and bauxite. A water treatment method characterized by using magnetism to recover a magnetically sensitive adsorptive material from treated water.