JPH0796115B2 - Water treatment contact material - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention uses, as a raw material, a water treatment contact material used for immobilizing and purifying microorganisms in a biochemical purification treatment of wastewater, rivers, etc., particularly granulated blast furnace slag. Water treatment contact material.

[0002]

2. Description of the Related Art In recent years, eutrophication of lakes and marine rivers has become a social problem in Japan, and the main source of pollution is not only purification of domestic wastewater and industrial wastewater but also polluted lake water. Purification of river water is also an urgent task.

As one of the methods for purifying these sewage,
There is a method in which a water treatment contact material such as gravel, plastic, zeolite, ceramics, and coke is submerged in water and biochemically treated by a microbial film formed on the surface.

By the way, most of the granulated blast furnace slag obtained by blowing a large amount of molten slag produced as a by-product in the iron making process is effectively used for various aggregates and the like. This granulated blast furnace slag contains components that promote the growth of microorganisms such as calcium, magnesium, iron and phosphorus.
It is also used as a raw material for the water treatment contact material for the above purpose.

Conventionally, as a water treatment contact material using granulated blast furnace slag, for example, those described in the following publications are known. <JP-A-57-75189> Granulated blast furnace slag having a diameter of 5 mm or more is used as it is. <JP-A-63-77596> A product obtained by mixing clay and a pore-forming material with ground granulated blast furnace powder having a particle size of about 40 to 150 μm, followed by molding and firing.

<JP-A-63-296891> A granulated blast furnace powder having an average particle size of about 200 μm and a synthetic resin are kneaded and molded into a saddle shape or a ring shape. <JP-A-63-296895> An adhesive layer is formed on the surface of a carrier material formed in a saddle or ring shape, and granulated blast furnace fine powder having an average particle size of about 20 to 500 µm is adhered to the adhesive layer. thing.

[0007]

However, the conventional water treatment contact material has the following problems. The gravel itself has a low porosity and water absorption rate per se, so that the adhesion of microorganisms is poor, and there are many areas where microorganisms do not adhere.
Small effective surface area per weight. Further, since the weight is heavy, it is difficult to handle, and since the particle size range is wide, the porosity in the tank becomes small when it is inserted into the processing tank, and there are disadvantages such that clogging is fast.

[0008] Plastic has a low porosity and a low water absorption rate, and its surface is too smooth, so that the adhesion stability of microorganisms is poor. Ceramics and zeolites are difficult to mold and expensive. Coke is not inferior to any of the above raw materials in terms of porosity and water absorption, but it is pulverized and clogged during use, and since it is originally used as a fuel, cost is low. It is expensive and not suitable for large-scale use as a water treatment contact material.

When the above raw materials are used,
In order to increase the surface area and facilitate the attachment of microorganisms, the shape of the water treatment contact material is string-shaped, tubular, net-shaped, honeycomb structure, etc., but the manufacturing cost increases because of the complicated shape and structure. Was inevitable.

When the granulated blast furnace slag having a diameter of 5 mm or more is used as it is, the shape of the blast furnace is not constant, and the unevenness of the surface is large, so that the treated water is unevenly flowed and the particle size composition is wide. However, there are drawbacks such as clogging.

A product obtained by mixing granulated blast furnace fine powder with clay and a pore-forming material and molding and baking it requires high-temperature treatment, and thus is costly. Further, the granulated blast furnace fine powder and synthetic resin are kneaded and molded into a saddle shape or a ring shape,
Porosity and water absorption are low. Furthermore, the one in which the granulated blast furnace granulated powder is adhered to the adhesive layer on the surface of the carrier material shaped like a saddle or ring requires the carrier material manufacturing step, the step of crushing granulated blast furnace slag, and the bonding step. However, the manufacturing cost is very high because the manufacturing process is complicated and an expensive adhesive is required.

[0012] Therefore, the object of the present invention is to obtain inexpensively by using granulated blast furnace slag, high porosity and water absorption and good adhesion of microorganisms, but less clogging, Another object of the present invention is to provide a water treatment contact material that is lightweight and has good workability.

[0013]

The water treatment contact material according to the present invention comprises, as a main raw material, a granulated blast furnace granulated slag having a particle size adjusted to 1 to 5 mm to 1 part by weight of the granulated blast furnace fine powder or this 0.1 to 0.4 parts by weight of a mixture of quick lime and a hydraulic binder is added, the humidity is adjusted and the mixture is kneaded, and the mixture is molded into a desired shape.

[0014]

The water treatment contact material according to the present invention is mainly composed of granulated blast furnace slag. The molten slag produced as a by-product in the iron-making process has various properties depending on the cooling method.
As one of the methods, when blast furnace slag in a molten state is flown through a blowing apparatus and cooled with pressure water of 1 to ³ kg / cm ² , it is instantly granulated to form granulated blast furnace slag. Most of the granulated blast furnace slag in this case is sandy, and the appearance is mostly grayish yellow glassy particles, and the particles have an infinite number of bubbles and have an angular shape. Therefore, it has a high porosity and a large surface area.

The granulated blast furnace slag contains calcium, magnesium, iron, phosphorus and the like, and the effects of these components on the treated water are as follows. (1) Calcium Corresponding to the fact that nitrogen is nitrated by circulating the treated water and the treated water is acidified, Ca ions eluted from the granulated blast furnace slag act as a neutralizing agent to grow microorganisms. An easy environment can be provided. Phosphorus, which is said to be the cause of eutrophication in lakes and marshes, reacts with Ca ions eluted from granulated blast furnace slag and can be fixed in the form of calcium phosphate. The Ca ions eluted from the granulated blast furnace slag have the effect of promoting the coagulation and precipitation action of SS (suspended suspended solids) in the treated water. (2) Magnesium, iron and phosphorus Magnesium, iron and phosphorus have the function of promoting the growth of microorganisms. In particular, granulated blast furnace slag has a high magnesium content and a low phosphorus content.

[0016] However, when granulated blast furnace slag is put into a packed bed in a mere form or in a grained state to remove powder, and the target water is passed through, the range of particle size composition is reduced in the case of a solid form. Since it is wide, the SS content affects and causes clogging, and since the grain preparation has a large surface, it has the drawback of causing a nonuniform flow of treated water. Therefore, it is conceivable to add cement to the granulated blast furnace slag to mold it into a desired shape and reduce the flow resistance.However, when the granulated blast furnace slag is solidified with cement, the growth of microorganisms as described above is performed. The granulated blast furnace slag, which has a component that promotes slag, is wrapped in cement and its effect is halved.

Therefore, in the present invention, granulated blast furnace fine powder having the same effect as granulated blast furnace slag is adopted as a hydraulic binder in place of cement. That is, the solidified molded product of the granulated blast furnace slag using the granulated blast furnace slag as a binder has a form in which the granulated blast furnace granulated slag is wrapped with the granulated blast furnace granulated slag having the same effect, Biochemical water treatment is possible without impairing the efficacy of.

In addition, quick lime is used as a stimulant in the present invention, if necessary, since the binder may not be able to have a sufficient initial strength when the ground granulated blast furnace powder is used alone. The reason why quick lime is selected from various stimulants is that Ca ions eluted from it have the effects described above. That is,
Quick lime reacts with ground granulated blast furnace powder to promote latent hydraulicity, maintain the shape of the molded product, and its main component is C
Since it is aO, when it is blended with the water treatment contact material of the present invention, like blast furnace granulated slag and blast furnace granulated fine powder,
It exerts effects such as neutralization of treated water, promotion of coagulation and precipitation of SS, and removal of phosphorus.

Sulfates are widely present in lakes, groundwater, and the ocean, and these sulfates react with calcium hydroxide produced by cement to produce calcium sulfate.
Next, generate a d [pi] n guide reacts alone hydrate _{4CaO · Al 2 O 3 · XH} 2 O in 3CaO · _Al 2 _{O 3} where part of the calcium sulfate is due to gypsum deficient (aluminum calcium oxide) At that time, a large volume expansion is caused to destroy the molded body. However, although the ground granulated blast furnace powder has much more Al ₂ O ₃ content than Portland cement, the sulfate resistance of this mixed cement is rather superior to that of Portland cement. The reason seems to be due to the difference in composition and structure of the aluminate phase.

On the other hand, the water treatment contact material of the present invention is used not only for the treatment of fresh water but also for treatment of sea water (for example, water for fish farming).
For the above-mentioned reason, the water treatment material using Portland cement as a binder may expand and collapse due to the sulfate in seawater. In view of the above, the present invention uses, as a binder, granulated blast furnace fine powder or a mixture thereof with quicklime.

As the method for molding the water treatment contact material of the present invention, a rolling granulation method using a pan type pelletizer and a compression molding method using a briquette machine are generally used. Since the fine particles are required for the raw material, the granulated blast furnace slag cannot be molded as it is, and can be molded only by grinding it. Moreover, the finished molded body becomes dense,
When it is used as a water treatment contact material, the treated water does not reach the inside of the molded body sufficiently, resulting in extremely low efficiency in contact with microorganisms.

In the present invention, in order to solve such a problem, granulated blast furnace slag is sieved and used to have a particle size adjusted to 1 to 5 mm as a raw material. If the particle size is 1 mm or less, the molded body becomes dense and the water permeability deteriorates.
When it is m or more, the surface area of the particles constituting the molded body becomes small, the treatment efficiency deteriorates, and the strength becomes weak. 1
In addition to being able to fully exhibit the above-mentioned properties of the granulated blast furnace slag, that is, the angular properties having innumerable bubbles, when the particle size is adjusted to ~ 5 mm, even if it is formed into a molded body, The particle size is appropriate for fixing with a hydraulic binder and maintaining the shape of the molded product.

Molding is performed by adding granulated blast furnace granulated slag with hydraulic granulated blast furnace granulated powder or a mixture of quick lime to this as a hydraulic binder, and adjusting the humidity and kneading (mixing with water) Pour into the frame. When adjusting the humidity and kneading,
A general mixing device such as a concrete mixer or a roller mixer, or a casting mold such as a wooden mold or a mold having a required shape and size can be used for the casting.

Since the molded product is, so to speak, a milled rice-like molded product rich in water permeability, it does not lower the porosity of the granulated blast furnace slag, and the molded surface and the inside are also porous, so that the microbial The adhesion is very good.

In the present invention, granulated blast furnace slag is used as the main raw material, but the purpose is to improve the grain size composition for the purpose of improving the moldability during casting into a mold and to improve the porosity of the molded product. A non-standard item of rock wool produced from blast furnace slag as a raw material, so-called waste cotton, may be added to the granulated blast furnace slag.

The amount of ground granulated blast furnace powder which is a hydraulic binder or a mixture of quick lime mixed with this is 0.1 to 0.4 part by weight per 1 part by weight of granulated blast furnace granulated slag. When the amount is 0.1 parts by weight or less, the strength of the molded product is insufficient, and there is a risk of collapsing during handling such as transportation or when inserted into a processing tank, and CaO elution is small, and the above effects are diminished. On the other hand, when the content is 0.4 parts by weight or more, the strength of the molded product improves, but the molded product becomes too dense and the porosity decreases, so that the function as a water treatment contact material decreases and the cost increases. .

[0027]

EXAMPLE FIG. 2 shows a procedure for producing a water treatment contact material according to the present invention. The granulated blast furnace slag having the components shown in Table 1 was sieved by a sieving machine only in a range of particle size of 1 to 5 mm. Fig. 1 shows granulated blast furnace granulated slag. To 85% of the granulated blast furnace slag having a particle size of 1 to 5 mm, 5% of quick lime as a hydraulic binder and 10% of granulated blast furnace fine powder, and an appropriate amount of water were added and kneaded in a kneader,
Pour into formwork, length 70mm, width 70mm, height 20m
m plate-shaped water treatment contact material was molded. After molding, the product was aged in a curing room for 3 days and taken out from the mold to obtain a product as shown in FIG. The specific gravity of this product (first example) was 1.40, and the water absorption rate was 27%. Further, with respect to 85% of granulated blast furnace slag having a particle size of 1 to 5 mm, quick lime 10% and granulated blast furnace fine powder 5% (second example), granulated blast furnace fine powder 15% (third example) Examples) were molded into the same size as above.

[0028]

[Table 1]

The following experiment was conducted to confirm the effects of the above four kinds of products. As the experimental method, as shown in FIG. 4, assuming that a sprinkling filter method is used, a large number of water treatment contact materials 1 are provided in a rectangular container 2 having an inner dimension of 80 mm × 80 mm and a height of 100 mm.
Fill inside, length 300mm, width 300mm, height 100
From the water tank 3 of mm, the primary treatment wastewater of the human waste treatment plant is sprayed on the upper portion of the rectangular container 2 by the metering pump 4 as the target water, and the treated water that has passed through the water treatment contact material 1 is discharged from the lower outlet of the rectangular container 2 to the water tank 3. Returned to. Reference numeral 7 indicates the recycled treated water. COD and BO of the target water due to changes with time at this time
D, TN and TP were measured. The same measurement was performed on the conventional product made of spherical plastic. The measurement results are shown in Tables 2 and 3. As can be seen from these tables, the water treatment contact material according to the present invention is COD, BOD, TN, TP.
It is far superior to conventional products in terms of removing.

[0030]

[Table 2]

[0031]

[Table 3]

Further, an experiment as shown in FIG. 5 was conducted. That is, assuming a dipping filter method, a large number of water treatment contact materials 1 are filled in a treatment tank 5 having an outlet of 200 mm in length, 300 mm in width, and 250 mm in height at the upper end, and 300 mm in length, 500 mm in width, and height. Primary treatment wastewater of a human waste treatment plant was put into a 400 mm water tank 3 as target water, the water was sent to a treatment tank 5 by a metering pump 4, and the treated water that passed through the water treatment contact material 1 was returned to the water tank 3. Further, in the water tank 3, bubbling with air was performed by the aeration device 6, and COD, BOD, T-N, and T-P of the target water with the lapse of time were measured. The same measurement was performed on the conventional product made of spherical plastic. The measurement results are shown in Tables 4 to 6. Also in this case, the water treatment contact material according to the present invention is COD, BOD, T-.
It is far superior to conventional products in removing N and T-P.

[0033]

[Table 4]

[0034]

[Table 5]

[0035]

[Table 6]

In the experimental apparatus shown in FIG. 5, the target water was replaced with tap water, three freshwater fish were placed in the water tank 3 as shown in FIG. 6, and bubbling and target water circulation were performed as shown in Table 7 to obtain COD. We observed the habitation of freshwater fish with changes.

[0037]

[Table 7]

In Table 7, in Test No. 1, bubbling and target water circulation to the water treatment contact material were performed from the beginning of the test, and from the 40th day, the circulation to the water treatment contact material was stopped and only bubbling was performed. COD by the 40th day is 6.8 ~
The value continued to show a low value of 9.7 mg / l, but the value gradually increased from the 40th day onward, and became 17 mg / l or more on the 47th day, and the fish died.

In test No. 2, when only bubbling was performed from the beginning of the test, COD was 16 mg on the 7th day.
/ L, and all the fish died on the 9th day. When the dead fish was removed and only bubbling was continued as it was, COD reached a very high value of 52 mg / l on the 40th day. From the 40th day, this contaminated target water was bubbled and circulated to the water treatment contact material.
The OD gradually decreased, and on day 55, it was recovered to 7.4 mg / l to a condition where fish could live.

From this experiment, COD shows a low value while the target water is purified using the water treatment contact material of the present invention, and the fish live but the bubbling alone causes C
It was found that the OD value gradually increased, and after a few days, the fish died. It was also found that the water treatment contact material of the present invention is harmless to fish inhabitation.

In the experimental apparatus shown in FIG. 5, the target water was replaced with river water having a low COD value, bubbling and circulation of the target water were performed, and the purification capacity of the water treatment contact material of the present invention was confirmed. Measurement items are COD, BOD, T-
Table 8 shows the measurement results for N and T-P. As can be seen from this table, the water treatment contact material of the present invention exhibits a remarkable purifying action even for low COD water.

[0042]

[Table 8]

[0043]

As described above, according to the water treatment contact material of the present invention, since the porous blast furnace granulated slag is used as the main raw material, the treated water can be kept neutral, and COD, BO
The removal performance of D, T-N, and T-P is also very good. Further, although the conventional water treatment contact material has a high removal rate for high COD water, it has little effect on low COD water, but the water treatment contact material of the present invention is effective for low COD water. However, it has a high degree of safety because it exerts a sufficient purification action and is harmless to fish habitat. Furthermore, since the main raw material is granulated blast furnace slag whose particle size is adjusted to 1 to 5 mm, it can be obtained at a low cost, and since the binder also uses blast furnace granulated fine powder and quick lime, it is an excellent organism for granulated blast furnace slag. In addition to being able to be solidified and molded into a desired shape without impairing the chemical water treatment performance and porosity, it is highly economical overall and is light in weight, so workability is good.

[Brief description of drawings]

FIG. 1 is an actual photograph of granulated blast furnace slag with a controlled particle size, which is the main raw material of the present invention.

FIG. 2 is a flowchart showing a manufacturing procedure of the water treatment contact material of the present invention.

FIG. 3 is an actual photograph of an example of the water treatment contact material of the present invention.

FIG. 4 is an explanatory view showing a performance test example of the water treatment contact material of the present invention.

FIG. 5 is an explanatory diagram of another test example.

FIG. 6 is an explanatory diagram of still another trial example.

[Explanation of symbols]

 1 Water Treatment Contact Material 2 Square Container 3 Water Tank 4 Metering Pump 5 Treatment Tank 6 Aeration Device 7 Recycled Water

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Katsuo Hattori 1 Kimitsu, Kimitsu-shi, Chiba Prefecture, in Tetsuhara Kimitsu Co., Ltd. (72) Inventor Noriyuki Kato 1 Kimitsu, Kimitsu-shi, Chiba Within Kumihara Kimitsu Branch (72) Inventor, Yoji Maekawa 1-4-4 Fujimi, Chiyoda-ku, Tokyo Iron and steel company (56) References JP-A-63-296891 (JP, A) JP-A-57-9840 (JP, A) JP-A-63-83231 (JP, A) JP-A-63-287596 (JP, A)

Claims (1)

[Claims] 1. A granulated blast-furnace slag having a particle size adjusted to 1 to 5 mm as a main raw material to 1 part by weight of the granulated blast-furnace pulverized powder or a mixture thereof with quick lime as a hydraulic binder. A water treatment contact material, characterized in that 1 to 0.4 parts by weight is added, the humidity is adjusted and kneaded, and the product is formed into a desired shape.