JPH0796116B2 - 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 relates to a water treatment contact material used for immobilizing and purifying microorganisms in a biochemical purification treatment of waste water, rivers, etc., and particularly, unwound rock wool or The present invention relates to a water treatment contact material made from the waste cotton.

[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.

[0004]

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.

[0005] Plastic has low porosity and water absorption, 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.

Rock wool is produced by melting a large amount of blast furnace slag or natural stone such as basalt and andesite in a steelmaking process in a cupola or electric furnace, and then fiberizing it by centrifugal force or pressure such as air or steam. Has been done.
In the production thereof, various kinds of waste cotton are generated in a cotton making step, a granulating step, a sieving step, etc. Further, various kinds of waste cotton are also generated when manufacturing various products using rock wool. This waste cotton is a random aggregate of short glassy fibers made of blast furnace slag or natural rock.It is not a fiber array with directionality and regularity like rock wool products, but the fibers are entangled with each other and sponge-like. It is what is doing. Moreover, the waste cotton has irregular shapes due to its generation, and since it is lightweight and bulky, it cannot be effectively used as it is, and most of it has been disposed of by landfill. Although it is a part, it was only to the extent that clay and a binder were added to waste cotton to form a briquette, which was reused as a part of the rock wool raw material (see, for example, JP-A-1-192743).

The object of the present invention is to effectively utilize rock wool waste cotton, which has been mostly landfilled as described above, to obtain water having higher porosity and water absorption and better adhesion of microorganisms than ever before. It is to make the treated contact material economically obtainable.

[0009]

The water-treatment contact material of the present invention is prepared by mixing loose crushed fine powder of blast furnace or quick lime with 1 part by weight of rock wool or its waste cotton as a main raw material. Was used as a hydraulic binder of 0.1
It is formed by adding up to 0.4 parts by weight, adjusting the humidity and kneading, and granulating into a desired shape.

[0010]

[Function] The unwound rock wool or its waste cotton is
Since it is a short fiber-like aggregate having irregular shapes due to its generation, it has a high porosity and a large surface area when molded, so that a microbial film is easily formed. Further, rock wool is mainly produced by using blast furnace slag as a main raw material, and thus waste cotton also has the following properties like blast furnace slag.

The 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 Nitrogen is nitrated by circulating the treated water, and the treated water is acidified. In response to the acidification of the treated water, Ca ions eluted from the blast furnace slag act as a neutralizing agent, and an environment in which microorganisms can easily grow. Can be provided. Phosphorus, which is said to be the cause of eutrophication in lakes and marshes, reacts with Ca ions eluted from blast furnace slag and can be fixed in the form of calcium phosphate. The Ca ions eluted from the 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, blast furnace slag has a high magnesium content and a low phosphorus content.

[0012] Therefore, the rock wool obtained from such blast furnace slag or its waste cotton contains a large amount of CaO (CaO, SiO, and Al ₂ O ₃ are the main components), and therefore functions as a water treatment contact material. In such a case, Ca ions are eluted, nitrogen is nitrated by circulating the treated water, and the neutralizing action works in response to the acidification of the treated water, thereby providing an environment in which microorganisms can easily grow. it can. It also has the effect of promoting the coagulation-precipitation action of SS (suspended suspended solids) in the treated water.

Furthermore, since P (phosphorus), which is considered to be the cause of eutrophication in lakes and marshes, can be fixed and removed in the form of calcium phosphate, it exerts an effect which has not been provided by the water treatment contact materials provided hitherto. . Further, rock wool and its waste cotton also contain FeO and MgO, although they are present in a small amount, and these also promote the growth of microorganisms, so that the water treatment contact material of the present invention is said to have excellent affinity with microorganisms. Become.

However, the unwound rock wool or its waste cotton is a short fiber having an irregular shape and cannot be used as a water treatment contact material as it is. Therefore, a hydraulic binder is added to adjust the humidity. -After kneading, rolling granulation is performed to obtain a molded body. In this case, it is possible to use an organic binder such as lignin or molasses, but when it is used as a water treatment contact material, the organic matter is eluted and mixed into the water, resulting in an increase in COD and BOD of the treated water and secondary contamination. As a result, the original function of the water treatment contact material is not fulfilled. Furthermore, in the case of an organic binder, there are some which are dissolved when they come into contact with water and cannot retain the shape of the molded product. It is also possible to use cement as a hydraulic binder, but when it is solidified and molded with cement, the components that promote the growth of microorganisms (blast furnace slag) are wrapped in the cement as described above, and the effect is halved. Resulting in.

Therefore, in the present invention, granulated blast furnace fine powder having the same effect as blast furnace slag is adopted as a hydraulic binder that replaces cement. That is, the solidified molded product of the blast furnace slag with the granulated blast furnace fine powder as a binder, the blast furnace slag has a form in which granulated blast furnace fine powder having the same effect is wrapped, so that the effect of the blast furnace slag is not impaired Enables biochemical water treatment.

In some cases, if the binder is not the ground granulated blast furnace powder, it may not be possible to give the molded product sufficient initial strength. Therefore, in the present invention, quick lime is used as a stimulant. 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 added to the water treatment contact material of the present invention, the effects of neutralizing the treated water, accelerating the coagulation and precipitation of SS, removing phosphorus, etc. are similar to those of blast furnace slag and granulated blast furnace fine powder. Exert.

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 seawater (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.

The unwound rock wool or its waste cotton is sponge-like in random shape and easily collapsed, so that it is difficult to mold it into a briquette. That is, even if pressure is applied to the mold for molding, when the pressure is released, it returns to its original state due to elasticity and lacks flexibility, and therefore it is difficult to mold. Therefore, conventionally, clay minerals have been added as a binder as described above, and the clay has penetrated into the fibers of the waste cotton to form a briquette.

In the present invention, rolling granulation is carried out by utilizing the voids between the fibers of the unwound rock wool or its waste cotton. The unwound rock wool or its waste cotton becomes viscous when it absorbs water.Therefore, add pulverized blast furnace fine powder or a mixture of quicklime to it as a hydraulic binder, and adjust the humidity and knead it as described above. Rolling granulation is possible.

A general mixing device such as a concrete mixer or a roller mixer can be used for controlling the humidity and kneading. Even for rolling granulation, a conventional granulating device such as a pan type pelletizer or a drum type pelletizer can be used. It can be used. Unwound rockwool or its waste cotton can be molded by rolling granulation without lowering the porosity, and the surface of the molded product becomes a rough surface with severe irregularities, so that the adhesion of microorganisms becomes good. . However, when molded into a briquette, a binder such as clay mineral is required as described above, the porosity is remarkably reduced, and the surface of the molded product becomes smooth, so that the adhesion of microorganisms becomes difficult. Further, there are disadvantages that the bulk density becomes large, the surface area per unit weight becomes small, and the weight increases when it is inserted into the processing tank.

The amount of ground granulated blast furnace powder used as a hydraulic binder or a mixture of this and quicklime is 0.1 to 0.4 parts by weight based on 1 part by weight of loosened rock wool or its waste cotton. It is a department. If it is less than 0.1 parts by weight, the strength of the molded product will be insufficient, and it may collapse during handling such as transportation or when it is inserted into a treatment tank.
Is less eluted, 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 is improved, but the molded product becomes too dense and the porosity is decreased, so that the function as the water treatment contact material is decreased and the cost is increased.

[0023]

EXAMPLE FIG. 2 shows a procedure for producing a water treatment contact material according to the present invention. Compared to 85% waste cotton of the components shown in Table 1,
5% quicklime as a hydraulic binder, 10% ground granulated blast furnace powder, and an appropriate amount of water were mixed and kneaded in a kneader, and then granulated by rolling while adding water in a granulator. ~
A 30 mm spherical water treatment contact material was molded. The waste cotton used at this time is shown in FIG. After molding, it was cured in a curing room for 3 days to obtain a product having a diameter of 20 to 30 mm as shown in FIG. This product (first example) has a specific gravity of 1.38 and a water absorption of 2
It was 0%. Also, for the same waste cotton 85%, quick lime 10% and granulated blast furnace fine powder 5% (second example),
Granulated blast furnace fine powder of 15% (third example) was molded in the same manner as above.

[0024]

[Table 1]

The following experiment was conducted to confirm the effects of the above four kinds of products. As shown in FIG. 4, assuming the sprinkling filter method, a large number of water treatment contact materials 1 were filled in a cylindrical container 2 having an inner diameter of 80 mm and a height of 100 mm as shown in FIG. From the 100 mm water tank 3, the primary treatment wastewater as a target water is sprinkled on the upper part of the cylindrical container 2 by the metering pump 4, and the treated water that has passed through the water treatment contact material 1 is discharged from the lower outlet of the cylindrical container 2 to the water tank 3. Returned to. 7 is the recycled treated water. COD, BOD, T-N, T-P of the target water due to changes with time at this time
Was 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 far superior to conventional products in removing COD, BOD, TN and TP.

[0026]

[Table 2]

[0027]

[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.

[0029]

[Table 4]

[0030]

[Table 5]

[0031]

[Table 6]

In the experimental apparatus shown in FIG. 5, the target water was changed to tap water, three freshwater fish were put 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.

[0033]

[Table 7]

In Table 7, in Test No. 1, bubbling and subject 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 until the 40th day is 7-10
The value continued to show a low value of mg / l, but the value gradually increased from the 40th day onward, and became 18 mg / l or more on the 45th day, and the fish died.

In test No. 2, when only bubbling was performed from the beginning of the test, COD was 15 mg on the 7th day.
/ L and all the fish died on the 10th day. When the dead fish was removed and only bubbling was continued as it was, the COD reached a very high value of 50 mg / l on the 40th day. As a result of bubbling and circulating the contaminated target water to the water treatment contact material from the 40th day,
The COD gradually decreased, and on day 55, the COD recovered to 8 mg / l and the fish could be inhabited.

From this experiment, COD shows a low value while the target water is purified by using the water treatment contact material of the present invention, and the fish inhabit, 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.

[0038]

[Table 8]

[0039]

As described above, according to the water treatment contact material of the present invention, since the rock wool obtained from the blast furnace slag or its waste cotton is the main raw material, the treated water can be kept neutral. The COD, BOD, TN and TP removal performance is also very good. Moreover, the conventional water treatment contact material has a high C
Although the removal rate was high for OD water, it was less effective for low COD water, but the water treatment contact material of the present invention exerts sufficient purifying action even for low COD water, Since it is also harmless with respect to fish habits, it is highly safe. Furthermore, since the main raw material is rock wool that has been disentangled or waste cotton that has been conventionally landfilled, it is extremely inexpensive, contributes to resource saving, and is lightweight and has good workability. Moreover, since granulated blast furnace fine powder or a mixture of quick lime is used as the hydraulic binder, it is solidified and molded into the required shape without impairing the excellent biochemical water treatment performance and porosity of the rock wool component. it can.

[Brief description of drawings]

FIG. 1 is an actual photograph of waste cotton as a 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 test example.

[Explanation of symbols]

 1 Water Treatment Contact Material 2 Cylindrical 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-2-5852 (JP, A) JP-A-57-9840 (JP, A) JP-A-63-83231 (JP, A)

Claims (1)

[Claims] Claims: 1. As a main raw material of the unwound rock wool or its waste cotton, 1 part by weight thereof is ground granulated blast furnace powder or a mixture thereof with quick lime as a hydraulic binder of 0.1 to 0. A water treatment contact material, which is obtained by adding 4 parts by weight, adjusting the humidity and kneading, and granulating the mixture into a desired shape.