JP4545408B2 - Water treatment material, nitrate nitrogen treatment material and production method thereof - Google Patents

Description

  The present invention relates to a sulfur-alkali (earth) metal carbonate-based nitrate nitrogen treatment material, and to a treatment material for denitrifying nitrate nitrogen in water by biological treatment with sulfur-oxidizing bacteria.

  Autotrophic sulfur oxidation is a technology that removes nitrate nitrogen in domestic wastewater, industrial wastewater, livestock wastewater, agricultural wastewater, and aquaculture wastewater that cause eutrophication in rivers, lakes, closed water areas, closed sea areas, etc. Unlike the system using heterotrophic denitrifying bacteria, the nitrate nitrogen removal system using denitrifying bacteria (hereinafter referred to as sulfur-oxidizing bacteria) does not require high maintenance costs such as the addition of methanol. Attention has been paid.

Regarding nitrate nitrogen removal system using sulfur-oxidizing bacteria (hereinafter referred to as denitrification system), for example, Japanese Patent Publication No. 62-56798, Japanese Patent Publication No. 63-45274, Japanese Patent Publication No. 60-3876, Japanese Patent Publication No. 1 -31958, JP 4-9199, JP 4-74598, JP 4-151000, JP 4-197498, JP 6-182393, etc. .
Patent Documents 1 and 2 below propose a denitrification system in which a sulfur-oxidizing bacterium is contained in a molten mixture of sulfur and limestone, and are excellent in terms of ease of maintenance and cost for denitrification treatment. Is shown. Patent Document 3 proposes a method of granulating with a press by mixing sulfur and limestone without heating without the steps of heating, melting, and rapid solidification of the denitrification material.

However, in the above-described method of integrating sulfur and limestone by heating and melting, limestone powder to be mixed and other additives are gradually added so as not to solidify again the sulfur dissolved in the heating kneader. In addition, it is necessary to preheat powder raw materials other than sulfur, and finally, it takes time and effort to cool and crush and classify, which may cause problems in productivity. Furthermore, the surface of the treated material produced by heating and melting of the sulfur is quite smooth, it may become unsuitable as a place bacteria breed since sulfur oxidizing bacteria by water flow or vibration is in the state easily disengaged .

  In addition, the method of mixing and pressing sulfur and limestone without heating as in Patent Document 4 can be applied not only to the batch type but also to continuous molding, so there is no need for pulverization and classification processes, and the productivity of the treated material is reduced. Can be improved. However, in the method of granulating only with the press, the binding force between the powders is weak, and the treatment capacity decreases or the processing material is replenished by gradually peeling and flowing out as sulfur and limestone powder from the surface during water treatment. Such a problem remains.

  In addition, when nutrient sources such as nitrogen and phosphorus are discharged to lakes and marshes, etc., they are gradually fertilized and algae grow and proliferate, causing so-called eutrophication. In addition, phenomena such as red tide, where the water quality deteriorates cumulatively, is a problem in terms of water quality conservation, and once the water quality has progressed, it becomes difficult to recover. In other words, in lakes and marshes, in addition to deterioration in aesthetics due to a decrease in transparency and a change in light blue, various problems such as filtration problems in the water supply and off-flavors are caused. In the sea area, damage to fisheries due to red tide and blue tide is becoming serious. Therefore, in order to prevent water pollution due to eutrophication and to preserve water quality, environmental standards related to nitrogen and phosphorus have been set and are becoming increasingly severe in recent years. However, a method for easily removing nitrogen and phosphorus at the same time has not yet been found. Although some water quality improvements in lakes and marshes are being observed due to the development of sewers and the regulation of industrial wastewater, many seas and lakes still do not improve water quality.

  Conventional dephosphorization methods include dialysis of phosphorus-containing salts by disposing an anion exchange membrane and a cation exchange membrane between the two plates using carbon for the positive plate and stainless steel for the negative plate. A separation method, a two-stage anaerobic treatment process and an aerobic treatment process are connected in series, a dephosphorization method of waste water formed by adding a flocculant (Patent Document 5), and after mixing septic tank sludge, A method of adding a polymer flocculant and biologically nitrifying and denitrifying the separated water (Patent Document 6), an aggregation dephosphorizing method of adding a specific proportion of lime to wastewater (Patent Document 7), and lime as a primary treatment As a secondary treatment, there is a dephosphorization method in which a polymer flocculant is added (Patent Document 8). However, none of these are sufficient in dephosphorization rate, dephosphorization efficiency, and the like. For example, for Patent Document 5, etc., the facilities are excessive, and the capital investment and operating costs increase. The agglomeration method using lime as disclosed in Patent Document 6 takes time to agglomerate and is not suitable for mass processing. There is also a dephosphorization method using a mixture of slag and magnesia adsorbent (Patent Document 9) and a mixture of slag and cement (Patent Document 10). However, since these are also in a powder form, so-called slime is generated by the dephosphorization process, and equipment such as a large thickener is required.

Japanese Patent Laid-Open No. 2001-47086 Japanese Patent Laid-Open No. 2001-104993 JP 2002-66592 A JP 2002-66592 A Japanese Patent Laid-Open No. 5-185091 JP-A-6-226290 Japanese Patent Laid-Open No. 54-129757 Japanese Unexamined Patent Publication No. 57-187092 JP 61-28491 A JP-A-61-64392

  Accordingly, an object of the present invention is to provide a relatively strong nitrate-nitrogen treatment material that is capable of continuous granulation, easily propagates bacteria, and is difficult to detach and has an excellent denitrification ability. It is another object of the present invention to provide a treatment material that can easily and simultaneously remove nitrate nitrogen and phosphorus which are causative substances of such environmental pollution.

  As a result of intensive studies in order to solve such problems, the present inventors have not separately used sulfur alone as a binder in the sulfur-carbonate system, but separately formulated a water-insoluble organic binder. Thus, the inventors have found that the above object can be achieved, and completed the present invention.

The present invention is a nitrate nitrogen treatment material used for denitrification of nitrate nitrogen by biological treatment with sulfur-oxidizing bacteria, comprising 30 to 70 parts by weight of calcium carbonate powder and 30 to 70 parts by weight of sulfur powder. A water-insoluble or hardly soluble organic binder derived from an organic polymer dispersed or dissolved in water or an organic solvent for integrating the powder with respect to a total of 100 parts by weight of both. It is a nitrate nitrogen processing material characterized by mix | blending 1-30 weight part. In addition, the present invention is the above-described nitrate nitrogen treatment material in which calcium carbonate powder and sulfur powder are integrated with an organic binder or attached to and supported on a support surface. Furthermore, this invention is said nitrate nitrogen processing material containing 1-100 weight part of inorganic additives with respect to a total of 100 weight part of calcium carbonate powder and sulfur powder.

  The method for producing a nitrate nitrogen-treated material according to the present invention comprises mixing an alkaline (earth) metal carbonate powder and a sulfur powder in an organic binder solution that gives a water-insoluble or hardly soluble organic binder, and uniformly kneading the mixture. And then removing the liquid.

  Furthermore, the water treatment material of the present invention is a water treatment material that denitrifies nitrate nitrogen by biological treatment with sulfur-oxidizing bacteria and also performs dephosphorization treatment, and the alkaline (earth) metal carbonate powder 30 ~ 70 parts by weight and 30 to 70 parts by weight of sulfur powder, and 0.1 to 30 parts by weight of a water-insoluble or hardly soluble organic binder for integrating the powder with respect to a total of 100 parts by weight of both. It is a water treatment material characterized by being mixed and dephosphorizing as well as denitrifying.

Hereinafter, the present invention will be described in detail.
The nitrate nitrogen treatment material or nitrate nitrogen and phosphorus treatment material (hereinafter also referred to as water treatment material) of the present invention is used as a denitrification material or a denitrification material / dephosphorization material. This water treatment material contains alkali (earth) metal carbonate (hereinafter also referred to as carbonate) powder, sulfur powder and water-insoluble or hardly soluble organic binder (hereinafter also referred to as organic binder) as essential components. Depending on the case, it can be composed of a carrier for supporting them or an inorganic additive added to them.

  Alkali (earth) metal carbonate is a compound that has carbonic acid as a carbon source for sulfur-oxidizing bacteria. Carbonate of alkaline earth metal such as calcium and magnesium, carbonate of alkali metal such as sodium, potassium and lithium. Examples thereof include salts, bicarbonates, and mixtures thereof. However, among them, calcium carbonate is abundant in nature as limestone, and has an appropriate water insolubility, so that it is particularly useful from the viewpoint of the life of the treatment material.

  The particle diameter of the carbonate powder is not particularly limited, but is preferably about several μm to several hundred μm. Originally, considering that microorganisms consume sulfur and carbonate, it is preferable to make the particles smaller in order to increase the contact area, but if it is too small, it tends to be difficult to handle. Moreover, since a large amount of binder is required for bonding, the above range is appropriate.

Examples of sulfur include, but are not limited to, sulfur recovered from petroleum desulfurization and coal desulfurization plants, natural sulfur, and the like.
The particle size of the sulfur powder is preferably about several μm to several hundred μm for the same reason as the particle size of the carbonate powder.

Conventionally, when such sulfur powder and carbonate powder are integrated, sulfur is melted and used as a binder, but in the present invention, an organic binder is separately used. As an organic binder, these powders can be adhered, and in order to treat nitrate nitrogen in water such as lakes, it is inevitably insoluble or hardly soluble in water.
As the binder, ceramic adhesives such as alumina and zirconia, and inorganic binders such as cement and gypsum can be considered. When adhering, it is disadvantageous because a considerable amount of addition is required. On the other hand, the organic binder has the advantages that the specific gravity is smaller than that of the inorganic binder, so that the addition amount is small, the granulation can be made uniform, and the adhesive strength is high.

  Examples of the organic binder used in the present invention include thermoplastic resins, thermosetting resins, and natural polymers. When such an organic binder acts as a binder with a curing reaction or the like like a thermosetting resin, it may be water-insoluble or hardly soluble after the curing reaction or the like. In the case of acting as a binder after evaporation of the solvent or solidification by cooling like a thermoplastic resin, it may be water-insoluble or hardly soluble before and after that.

  It is convenient to use an organic polymer dispersed or dissolved in water or an organic solvent because it is simple and can be granulated uniformly. That is, the state of the organic polymer used for granulation is preferably a dispersion dispersed in water and a state dispersed or dissolved in an organic solvent. Those organic polymers dispersed in water include, for example, styrene, acrylic, epoxy, urethane, vinyl chloride emulsion, natural rubber latex, synthetic rubber latex such as chloroprene rubber and styrene butadiene rubber, or Examples include bituminous emulsions such as asphalt and paraffin. The organic polymer dissolved in the organic solvent includes amorphous thermoplastic resins such as styrene, acrylic and polycarbonate, thermosetting resins before curing such as epoxy and urethane, Examples include natural polymers such as asphalt and natural rubber. Examples of organic solvents include aromatic solvents such as toluene and xylene, ketones such as acetone and ethyl acetate, hydrocarbon solvents such as ester solvents and petroleum ether, and natural solvents such as limonene. Absent.

  The water treatment material of the present invention is preferably obtained by integrating and granulating carbonate powder and sulfur powder with an organic binder. The grains are effective for increasing the contact area between the microorganisms (bacteria) living on the treatment material and the treatment liquid. The size of the grains is, for example, 1 to 100 mm, preferably 2 to 50 mm. On the other hand, if the powder is finer than the above particles, the contact area is larger and the denitrification effect is higher, but it is practically difficult to handle and easily flows out during use.

  Denitrification proceeds if carbonate powder and sulfur powder are uniformly present on the surface of the carrier, even if it is not a grain, so that it may be supported by carbonate powder and sulfur powder on the surface of the carrier. preferable. In this case, the size of the water treatment material is, for example, 1 to 100 mm, preferably 2 to 50 mm. By using the carrier, not only the amount of carbonate powder and sulfur powder used can be reduced, but also a complicated shape can be obtained, so that the surface area can be increased.

  The carrier is not particularly limited as long as it can support sulfur powder and carbonate powder on the surface of the carrier with an organic binder. Accordingly, as the carrier, there are a relatively small carrier that can be kneaded simultaneously with the sulfur powder and the like, and a relatively large carrier that can be kneaded simultaneously with the sulfur powder and the like so that a slurry such as the sulfur powder is applied, and both can be used. In terms of diameter, it is a single particle with a powdery (granular or fibrous) one that looks under 5 mm, a small carrier, and a one that exceeds 5 mm with a molded product or a coarsely crushed product that is a large carrier. The small carrier may be particles or fibers, and the large carrier may be a processed product or a crushed product thereof.

  By using a carrier having a large particle size, the sulfur powder and carbonate powder can be coated on this surface to be a nitrate nitrogen treatment material adhered and supported on the surface of the carrier. As the coating method, a method of adhering or applying a liquid or slurry containing sulfur powder, carbonate powder and an organic binder to a carrier and drying or cooling is preferably exemplified. Examples of such carriers include woven fabrics and nonwoven fabrics of various fibers, molded products, other minerals, polymer materials, wood, charcoal, metal, ceramic molded products, organisms such as pumice or shells, bones, corals, etc. It is not limited.

  When a carrier having a small particle size is used, the sulfur powder, carbonate powder and carrier are mixed almost uniformly and integrated with an organic binder to obtain a water treatment material. In this case, it can be formed into a specific shape. Examples of small carrier particles include sand, coral sand, perlite, granulated slag, zeolite, diatomaceous earth, fly ash, shirasu balloon, mica and other various mineral particles. The fibers include natural mineral fibers such as wollastonite, sepiolite, asbestos, artificial mineral fibers such as rock wool, glass wool, ceramic fibers and carbon fibers, or organic fibers such as cellulose, nylon, polypropylene and polyethylene. It is not limited to.

Since the surface of the water treatment material of the present invention has a microscopically uniform sulfur powder and carbonate powder as an aggregate of particles, it has severe irregularities and a large amount of voids in the particles. Therefore, the specific surface area is much higher than that of the sulfur heating and melting method, the microorganisms are easy to propagate, and they are not easily lost even by an impact such as water flow or vibration.
In the present invention, the term “carrier” refers to a case where it usually occupies 50% or more of the whole when the carrier has a small particle size. It is possible to use a plurality of types of carriers, and in this case, the above calculation refers to the total. Moreover, the component normally added in less than 50v% is called an additive.

It is also preferable that the treatment material of the present invention contains an equal amount or less of an inorganic additive with respect to the sum of sulfur powder and carbonate powder. Such a treatment material is preferably a granulated powder obtained by integrating carbonate powder, sulfur powder and an inorganic additive with an organic binder. The size of the grains is, for example, 1 to 100 mm, preferably 2 to 50 mm.
Such an inorganic additive has the same components as those of the small carrier, but is not included when acting as a carrier. In addition, flame retardants such as aluminum hydroxide and magnesium hydroxide, hydrogen sulfide generation inhibitors such as iron oxide, and the like may be added as necessary.

  As each content contained in the water treatment material of this invention, 0.1-30 (weight)% of an organic type binder is good first. If it is less than 0.1%, carbonate powder such as sulfur and limestone cannot be firmly adhered, and the powder may be peeled off during denitrification. On the other hand, if it exceeds 30%, the powder can be firmly adhered, but carbonates such as sulfur and limestone necessary for denitrification are covered with organic polymers and cannot be used effectively, and the voids in the grains are reduced. Can not increase the activity of microorganisms. When no carrier or additive is used, the blending amounts of sulfur, carbonate and organic binder are determined within the above range.

  When using a carrier, the amount of the carrier is determined according to the method of using the treatment material (for example, just immersing it in the treated water, sprinkling the treated water, fluidized bed type, circulation method, etc.), capacity, shape, volume and weight of the carrier. Varies by That is, if the amount of sulfur powder is very small compared to the carrier (for example, about one thin skin), the contact area is enormous and the processing speed becomes very high. . Therefore, when importance is attached to the lifetime, the sulfur powder and the like should be increased from the support, and in order to increase the processing speed, the sulfur powder and the like should be decreased from the support.

  The water treatment material of the present invention is preferably a granulated granule, and may have a uniform size or shape, may be irregularly shaped and have a size distribution, and has an average diameter. It is desirable to be in the range of 1-50 mm. The method of granulating (pulverized) is preferably exemplified by a method of kneading and granulating with a continuous extruder, for example, before removing water or an organic solvent.

In the method for producing a nitrate nitrogen denitrification material of the present invention, carbonate powder and sulfur powder are blended with an organic binder dispersed or dissolved in a liquid such as water or an organic solvent and uniformly kneaded. Later, this is a method of drying. In this case, it is preferable to perform granulation after kneading to obtain a predetermined particle size.
For example, an organic binder dispersed in a predetermined amount of water or an organic solvent and a predetermined amount of sulfur, carbonate powder, and a carrier or additive such as particles and fibers added as necessary, are added to the treatment material manufacturing container, After uniformly kneading with a kneader, for example, a homogenizer, a kneader, or a stirrer, the nitrate nitrogen denitrification treatment material can be produced by removing moisture and organic solvent by drying with a dryer, blower or natural drying.

Improvement of the curing or adhesion of the organic binder proceeds by drying, heating, etc., but it is preferable to gradually cure without heating. For example, in the case of a liquid epoxy resin, if a main agent and a curing agent are mixed, the liquid epoxy resin is cured without applying high heat and has sufficient strength in the present invention. Thermoplastic resins are in a solidified state at room temperature, but some are dissolved in an emulsion or an organic solvent dispersed in water. Such thermoplastic resins are solidified when water or the solvent is exhausted. Given that the sulfur powder is flammable, it is desirable to avoid heating.
After removing water or the organic solvent, it may be an appropriate particle size by pulverization or the like. The method for removing water or the organic solvent may be a known method such as natural drying, high temperature drying or vacuum drying.

  Furthermore, as a method of adhering sulfur powder and carbonate powder to the surface of the carrier, after applying or spraying slurry prepared by mixing sulfur powder, carbonate powder and organic polymer at the same time, water or organic solvent is removed. It can be made to adhere by doing. Alternatively, the carrier can be adhered to a dispersion or solution impregnated or wetted with an organic polymer in advance by applying water or an organic solvent after applying sulfur powder and carbonate powder, It is not limited to this method. The method for removing water or the organic solvent may be a known method such as natural drying, high temperature drying or vacuum drying, as in the case of granulating.

  In the case of integrating (adhering) sulfur powder or the like with an organic binder and in the case of further integrating the carrier, it is possible to carry sulfur or the like on the carrier surface by kneading simultaneously with the sulfur powder or the like in a relatively small carrier. In the case of a relatively large carrier, it is difficult to carry it at a time, and it is preferable to first form a sulfur powder or the like in a slurry state and then apply this slurry to the carrier.

  There is no limitation on the method of removing nitrate nitrogen using the water treatment material of the present invention or removing phosphorus simultaneously, and the method of use described in the above-mentioned publications can be employed. When removing phosphorus such as phosphoric acid at the same time, alkali (earth) metal is also consumed by phosphoric acid, etc., so the blending amount of alkali (earth) metal carbonate is within the above range with respect to sulfur. It is better to make more.

  The nitrate nitrogen treatment material (water treatment material) of the present invention can exhibit excellent denitrification ability, its production is simple, and treatment for denitrification of nitrate nitrogen in water by biological treatment with sulfur-oxidizing bacteria Excellent as a material. Furthermore, it is a water treatment material that can easily and simultaneously remove nitrate nitrogen and phosphorus, which are environmental pollutants, and is extremely useful for water quality environmental conservation.

Nitric acid nitrogen treatment materials are sulfur (200 mesh, manufactured by Karuizawa Seisen), calcium carbonate (T-200, manufactured by Nichetsu), various carriers: non-woven fabric (PET fiber, manufactured by Toa Anticorrosion), rock wool (S fiber granular cotton, Nippon Steel) Chemical), granulated slag (average particle size 1 mm, manufactured by Nippon Steel Chemical Co., Ltd.) and organic binder (polystyrene resin, urethane resin) were prepared according to the formulation shown in Table 1.
The compounding quantity of an organic binder shows the numerical value as solid content. The polystyrene resin as the organic binder is a 5% solution of Toyo Styrene's high impact polystyrene (product name: XL4) diluted in toluene, and the urethane resin as the thermosetting resin is Dainippon Ink & Chemicals ( A water dispersion type urethane resin (product name: 1980NS) manufactured by Co., Ltd., adjusted to a resin content of 2 to 20% was used.

Example 1 (reference example), Example 2
Put a predetermined amount of sulfur powder and calcium carbonate powder in a 1000 ml glass beaker, mix well, adjust to a predetermined concentration with water or toluene, add an organic binder, and evenly with a metal spatula so that the whole powder gets wet well Stir and mix. In a constant temperature layer of 60 ° C., it was left to stand for one day and night to completely remove water or organic solvent, and a lump of the solidified treatment material was lightly beaten with a mallet and pulverized. The granular water treatment material used for the denitrification treatment was 5 to 20 mm. In addition, since Example 1 has a large amount of organic binder, the concentration of nitrate ions after 3 days is slightly high, which is a reference example.

Example 3
Nonwoven fabric was used as the carrier. First, the carrier is thoroughly moistened with a predetermined amount of an organic binder adjusted to a predetermined concentration with water, and then a powder mixed with a predetermined amount of sulfur and calcium carbonate is uniformly applied to the surface of the nonwoven fabric carrier with a metal spatula. . The coating amount was 6 g per 100 cm ^{2 of} nonwoven fabric in terms of weight after drying. In a constant temperature layer of 60 ° C., it was left for one day and night to completely remove water.

Examples 4-8
Fiber or slag was used as the carrier. A fiber or slag carrier is added, and an organic binder is added in an amount adjusted to a predetermined concentration with water or toluene so that the carrier is fully wetted. Next, a mixture of a predetermined amount of sulfur and calcium carbonate is added and mixed uniformly with a metal spatula. In a constant temperature layer of 60 ° C., it was left for one day and night to completely remove water or an organic solvent, and a lump of the solidified treatment material was lightly beaten with a mallet and pulverized. The granular water treatment material used for the denitrification treatment was 5 to 20 mm.

Comparative Examples 1-3
Except that the organic binder was not used (Comparative Example 1), the organic binder was too little (Comparative Example 1), on the contrary, the amount was too much (Comparative Example 3), and the blending ratio was as shown in Table 1. In the same manner as in Example 1, a water treatment material was obtained.

Comparative Examples 4-7
A treated material was obtained in the same manner as in Examples 4 to 8 except that the composition shown in Table 3 was used.

  The nitrate nitrogen treatment materials of Examples 1 to 8 and Comparative Examples 1 to 3 were used to remove nitrate nitrogen in water. That is, 100 ml of a solution of 200 mg / l of nitrate ion adjusted with potassium nitrate is added to 200 ml of polyvin, and 20 g of each treatment material shown in the table (the amount excluding the carrier when there is a carrier) is added, and further stirred. After deaeration, 0.1 g of dry sludge containing sulfur-oxidizing bacteria prepared in advance was added and stirred well, left in a thermostatic bath at 25 ° C. for 3 days, and nitrate ion was determined by ion chromatography. The concentration of was measured.

Tables 1 to 3 show blending ratios and denitrification treatment results. In the table, the number indicating the blending amount is part by weight. The applicability means workability and strength (whether powder is likely to be generated after drying) when a slurry made of sulfur powder or the like is adhered to the surface of the carrier. The granulation property is the granulation property when no carrier is used, and is determined according to the following criteria.
Evaluation of granulation property: ○: Can be easily manufactured, × 1): It takes time and effort by the conventional heating and melting method of sulfur and calcium carbonate. The granulated product is hard but generates a large amount of powder. × 2) Since there is too little binder, a large amount of powder is generated and granulation is impossible.

Example 9 and Comparative Example 8
200 g of each of the water treatment materials obtained in the same manner as in Example 2 and Comparative Example 1 was put into a 500 ml beaker together with 300 ml of nitric acid solution of 880 mg / l nitrate ion adjusted with potassium nitrate, and further pre-adjusted sulfur oxidation 1.0 g of dried sludge containing bacteria was added and stirred well, and left in a thermostatic bath at 25 ° C. for 10 days. As a result, a water treatment material carrying sulfur-oxidizing bacteria was obtained, and this water treatment material was used as a simultaneous removal material for nitrate nitrogen and phosphoric acid.
That is, 500 ml of a solution of nitrate ion 200 mg / l and phosphate ion 100 mg / l adjusted with potassium nitrate and sodium phosphate was placed in a circulating treatment tank, and this solution was treated with 200 g of the water treatment material for 32 hours. Denitrification performance and dephosphorization performance were performed by measuring the concentration of nitrate ion and phosphate ion by ion chromatography.
In this case, circulation was performed intermittently at a rate of 1 minute / 4 hours using a pump of 600 ml / min.
The results are shown in Table 4 below.

  From this, it is clear that a water treatment material using an organic binder not only has a higher ability to treat nitrate nitrogen than a material not using an organic binder, but can also treat more phosphoric acid at the same time.

Claims (5)

A nitrate nitrogen treatment material used to denitrify nitrate nitrogen by biological treatment with sulfur-oxidizing bacteria, comprising 30 to 70 parts by weight of calcium carbonate powder and 30 to 70 parts by weight of sulfur powder, 0.1-30 weight of water-insoluble or hardly soluble organic binder derived from an organic polymer dispersed or dissolved in water or an organic solvent for integrating the powder with respect to 100 parts by weight of both A nitrate nitrogen treatment material characterized by being partly blended. The nitrate nitrogen treatment material according to claim 1, wherein the calcium carbonate powder and the sulfur powder are integrated with an organic binder. 2. The nitrate nitrogen treatment material according to claim 1, wherein the calcium carbonate powder and the sulfur powder are adhered and supported on the surface of the carrier by an organic binder. The nitrate nitrogen treatment material according to any one of claims 1 to 3 , comprising 1 to 100 parts by weight of an inorganic additive with respect to 100 parts by weight of the total of calcium carbonate powder and sulfur powder. An organic system containing 30 to 70 parts by weight of calcium carbonate powder and 30 to 70 parts by weight of sulfur powder and dispersed or dissolved in water or an organic solvent for integrating the powder with respect to a total of 100 parts by weight of both. It contains 0.1-30 parts by weight of a water-insoluble or hardly soluble organic binder derived from a polymer, and is used for denitrification of nitrate nitrogen by biological treatment with sulfur-oxidizing bacteria. In producing a nitrogen-treated material, calcium carbonate powder and sulfur powder are mixed in an organic binder solution that gives a water-insoluble or hardly soluble organic binder, and after kneading uniformly, the liquid is removed. Manufacturing method of nitrate nitrogen treatment material.