JPH09187775A - Hard-to-disintegrate magnesia ph adjustor for improving water quality and bottom quality - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve the inhabitation environment for fish and aqueous organisms by forming a pH adjustor of specified several kinds of magnesia materials and constituting so that the powdering rate after the pH adjustor is mixed in water and the specified time has passed may be at most a set %. SOLUTION: A hard-to-disintegrate magnesia pH adjustor for improving the water quality and bottom quality is composed of one or two kinds or more of magnesia materials. The powdering rate after putting the pH adjustor into water and one hour having passed is specified as 10% or less. The bulk density of the pH adjustor is set beyond 2.3g/cm<3> . A magnesium oxide material heated up to 1000 deg.C or over can be used. Also a formed material or a crushed material of a powdery raw material formed by heating natural magnesia ores at the decomposition temperature or over can be used. The pH can be increased by 0.5% or more by scattering the material all over a zone to be improved at the rate of 1kg per 1m<2> . Also the pH can be increased by 0.5 by adding the material at the rate of 50g per 1m<3> . Also the pH can be increased by 0.5 or more by applying water of SV=1 or more into a filled layer.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to fish and fish by keeping the pH of water in the inland sea, inner bay, lakes, rivers and breeding aquariums, etc. The present invention relates to a magnesia-based pH adjusting agent for improving the habitat of aquatic organisms.

[0002]

2. Description of the Related Art In recent years, in closed water areas such as inland seas, inland bays, lakes and marshes, which have large pollution sources in the hinterland, inflowing pollution load is large and pollutants are easily accumulated. , Water and bottom sediment is becoming more polluted. In particular, in the closed waters such as the Seto Inland Sea and Ise Bay, phosphorus and nitrogen that have flowed in are stagnant, and red tides cause damage to the fishing industry, which has a great impact on the fishing environment. In addition, in lakes that are the source of drinking water represented by Lake Biwa,
Abnormal occurrence of freshwater red tide and blue-green alga causes problems of filtration failure and offensive odor in water supply facilities. In rivers, eutrophication occurs due to inflow of domestic wastewater and factory wastewater,
The water quality and bottom quality are deteriorated, giving off a foul odor and making it impossible for aquatic organisms to survive. In order to deal with this, the Water Pollution Control Law, Seto Inland Sea Environmental Conservation Special Measures Law, and drainage regulations for nitrogen and phosphorus related to lakes and marshes have been established and implemented. Moreover, due to the inflow of acidic hot spring water into rivers called acidic rivers, the pH of the water quality is extremely lowered, and there are places where living things cannot live.

[0003] In the farm, poisonous hydrogen sulfide is generated from the bottom sediment due to the generation of red tide and oxygen-deficient water mass, and it has been reported that a large amount of cultured fish is killed.

In the aquaculture industry for fish and aquatic organisms, eggs are artificially hatched in an aquarium or the like installed on land or the like, bred until they grow to a certain size, and then moved to another farm to be marketed. It is cultivated until it is shipped to. In addition, fish and aquatic organisms are bred all year round in aquariums and other aquariums. In these breeding aquariums, nitrate ions, etc. accumulate due to the accumulation of food residue (remaining food) and excrement from organisms that are provided for the growth of organisms, which leads to deterioration of water quality and sediment quality, and especially pH. Was a problem.

This decrease in pH directly affects the breeding organisms, resulting in slow growth of the breeding organisms, a high death rate during the breeding period, and a decrease in the yield when landing, leading to aquaculture. Was suffering a lot of damage.

There are two types of breeding water tanks, a circulating water tank and a running water tank. The former is a system in which water is circulated by using a pump, and the latter constantly overflows water to generate new water. It is an aquarium that has been replaced.

In the former circulation type water tank, as a measure against pH decrease, it is conventionally used by replacing with fresh water or by filling quick lime, slaked lime, coral sand, and oyster shell as a pH adjusting agent in order to raise the pH. However, it was not possible to stably maintain the pH of water / sediment at an alkaline level by the conventional method. This is p of conventional quick lime and slaked lime
This is because with the H regulator, the regulator was disintegrated and pulverized while circulating water, which was a cause of polluting the water quality in the circulating water tank. Further, while the pH of ordinary seawater is around 8.2, it is difficult to raise the pH of water to pH 8 with these pH adjusters because the main components of coral sand and oyster shells are calcium carbonate.

[0008] In the latter type of running water tank, especially when breeding creatures inhabiting the bottom, the pH of the breeding water was maintained at a normal pH because new water was constantly replaced, but the bottom of the aquarium kept residual food and Excreta, etc. were accumulated, which caused deterioration of bottom sediment. Therefore, there has been a problem of pH decrease. As a measure against this pH drop, the same conventional pH as the former
Although the regulator has been used, since there is a water stream constantly flowing out of the system, the regulator that is conventionally disintegrated after being poured into water is discharged out of the system by this water stream. For this reason, it was not possible to stably maintain the pH of the sediment at an alkali (for example, seawater at pH 8.1) for a long period of time.

In addition, in the circulation-type aquarium,
There is a method of replacing with new water as a measure for lowering the pH, but in the case of an aquarium laid in an aquarium, offshore seawater is required, and frequent replacement requires a large amount of money. In addition, lime-based regulators such as quick lime and slaked lime used as a method for increasing pH are strong alkalis, and have a great adverse effect on the habitat of fish and aquatic organisms.
Further, calcium carbonate is generated by the reaction with carbon dioxide gas in water and coats the surface of the regulator, so that the period for raising the pH is very short. For this reason, it was necessary to constantly add an adjusting agent in order to raise the pH. Further, there has been a problem that the produced compound such as calcium carbonate is deposited.

In a running-water-type rearing tank, coral sand, oyster shells, etc. are composed mainly of calcium carbonate, and a pH is raised because a precipitate is formed on the surface by reaction with phosphate ions in water. The period of time during which it can be treated is very short, and the pH is limited to 7.8-7.9.
There was a problem that it could not recover from 1 to 8.3. Furthermore, in the conventional pH adjusting agents for quick lime and slaked lime,
During the circulation of water, the water was disintegrated and pulverized, the water quality in the circulating water tank was polluted, and the environmental deterioration of the breeding organisms became a problem. In addition, when a creature living at the bottom is kept in a running water aquarium, a decrease in pH due to deterioration of the sediment causes an increase in bacteria and viruses, and the creature in the aquarium becomes ill, resulting in a decrease in yield.

Further, in the inland sea, inland bay, lakes, rivers, etc., the above-mentioned conventional p is used for the purpose of improving the bottom and water quality.
When the H-conditioning agent is poured into water, it immediately disintegrates and becomes powdery and scattered at the bottom. Therefore, when the storm blows, the bottom is washed out and flows out of the feeding area to modify the target area. Therefore, the economical problem was caused such that it was necessary to spray the pH adjusting agent again. Also,
Lime-based materials such as quick lime, slaked lime, coral sand, oyster shell and limestone, which are conventional pH adjusters, are used for inland sea, inner bay, lakes,
Sulfate ions dissolved in the water of rivers easily formed hardly soluble gypsum (calcium sulfate), which covered the surface of the regulator. Therefore, the effect of the pH adjuster is lost, and it is impossible to adjust the pH for a long period of time. Therefore, the appearance of a material capable of raising the pH of low-pH water to a high pH over a long period of time by spraying once has been awaited.

In view of the above problems, the inventors of the present invention have made diligent studies, and as a result, by spraying or filling the water quality and bottom sediment pH of the above-mentioned inland sea, inland bay, lake, river and breeding aquarium once for a long period of time. We have developed a magnesia-based pH adjuster that can improve the habitat of fish and aquatic organisms by maintaining it at an alkaline level.

[0013]

DISCLOSURE OF THE INVENTION The present invention for solving the above-mentioned problems is composed of one or more materials of magnesia type, and has a pulverization rate 1 hour after being placed in water. A magnesia-based pH adjuster characterized by being 10% or less, preferably having a bulk density of more than 2.3 g / cm ³ , and the magnesium-oxide-based magnesia-based material obtained by heating the above-mentioned magnesia-based material at 1000 ° C. or more. The material is a material obtained by heat-treating a naturally occurring magnesia-based ore at a decomposition temperature or higher, and is further characterized by being a molded product of a granular material mainly composed of a magnesium compound or a crushed product thereof. 1 kg or more per 1 m ^{2 of} quality zone The pH can be raised by 0.5 or more by spraying the modifier, and the pH can be raised by 0.5 or more by adding 50 g or more per 1 m ^{3 of the} water to be reformed. SV = 0 pH by more than passing water.
It is a hard-to-disintegrate magnesia-based pH adjuster for improving water quality and sediment that can be increased by 5 or more.

The hard-to-disintegrate magnesium-based pH adjusting agent of the present invention does not immediately disintegrate and powder even when added to water, and therefore does not pollute the water quality and the bottom material during use. Also, unlike the lime type, the magnesia type does not form a hardly soluble substance even when it reacts with sulfate ions etc. dissolved in water, so it is possible to maintain alkalinity for a long period of time. It becomes possible to provide a living environment for living things.

The present invention will be described in detail below.
Magnesium oxide, which is the present invention, is magnesium oxide,
Examples include one or more magnesium-containing material materials such as magnesium hydroxide and magnesium carbonate.

Magnesium oxide is once heated to a melting point or higher by a naturally occurring sintered magnesia clinker obtained by thermally decomposing brucite (hydrotalcite) and magnesite (rhydromethorite) which are naturally produced, and an electric arc. After melting, solidified natural fused magnesia or synthetic magnesium hydroxide obtained by adding alkaline raw material such as lime milk to magnesium-containing aqueous solution such as seawater, bitter juice and brackish water is heated and decomposed to be oxidized. Examples thereof include a sintered body of magnesium (synthetic sintered magnesia clinker) or an electromelted product (synthetic fused magnesia).

Furthermore, brucite, which is a naturally occurring magnesia-based ore, mainly made of magnesium hydroxide, is decomposed at a decomposition temperature of 350.
Also included is a magnesium oxide-based material usually called light-burning magnesia, which is obtained by treating magnesite mainly composed of magnesium carbonate at a heating temperature of ℃ or higher or at a decomposition temperature of 900 ℃ or higher. The main constituent mineral of these materials is periclase (magnesium oxide crystal), but usually contains undecomposed magnesite and brucite. However, these can be applied as the hardly soluble magnesia-based pH adjuster of the present invention without impairing the function as the magnesia-based pH adjuster of the present invention.

In addition, it is possible to use the natural magnesia-based ore as it is.

Further, naturally-occurring dolomite, the same heat-treated dolomite clinker, or a mixture of magnesium hydroxide and slaked lime, which are generally called synthetic dolomite, and heat-treated, etc. may be mentioned.

Of these magnesia-based materials, preferably 100
It is desirable to use a magnesium oxide-based material that is heated at a temperature of 0 ° C. or higher and sintered or electrofused. Since these magnesium oxide-based materials have a high MgO content per material, the input amount per unit area or unit volume is small, and it is considered to be a more economical material. This 10
Examples of the magnesium oxide-based material which is heated at a temperature of 00 ° C. or higher and sintered or electrofused include the above-mentioned naturally-produced sintered magnesia clinker, naturally-produced electro-fused magnesia, synthetic sintered magnesia clinker and synthetic electro-fused magnesia. Is mentioned.

Further, a granulated product obtained by molding a powder or granular material such as magnesium hydroxide or magnesium oxide, and a crushed product thereof can also be mentioned. In some cases, it is possible to add a binder during molding.

Further, it is desirable that the present material preferably has a size of 1 mm or more. In the improvement of bottom sediment, the larger the particle size is, the easier it is to sink, and when the bottom sediment is sludge-like, it is easy to be buried inside the sludge. It is because it becomes difficult to be washed away by being buried in the water.

Among the magnesium-based pH adjusters of the present invention, the bulk density of the granulated product immediately after molding is closely related to the disintegration property, and the higher the bulk density, the more the disintegration property is lost. Therefore, in order to prevent the material from collapsing after being poured into water, it is preferable that the bulk density is more than 2.3 g / cm ³ . This is because if the bulk density is 2.3 g / cm ³ or less, the material is likely to collapse immediately after being poured into water, and the effect of adjusting the pH is lost for a long period of time. One of the reasons for this is that when this material is put into the above-mentioned running water breeding aquarium or a water area with a fast flow, it is discharged out of the system by the flow.

It is important that the magnesia-based pH adjusting agent of the present invention has a pulverization rate of 10% or less at the time when 1 hour has elapsed after being put into water. The pulverization rate as used herein refers to the rate of generation of particles smaller than the particle size before the addition, which is caused by disintegration, in the material that has been placed in water for 1 hour. Therefore, the smaller this value is, the more difficult it is to collapse. When the pulverization rate exceeds 10%, the specific surface area of the material increases, so that the pH adjusting function increases, but the material dissolves and disappears quickly, and the effect of adjusting the pH is lost for a long period of time. Therefore, it is necessary to add the pH adjusting agent again, which causes an economic problem.

The magnesia-based pH adjusting agent of the present invention contains 1 kg per 1 m ² of water to be reformed and the area to be reformed of the bottom sediment.
It is preferable that the above-mentioned spraying is performed. If the amount of spraying is less than 1 kg, the pH adjustment capability is small, and thus the increase in pH becomes insufficient.

Further, when there is no communication with the outside of the system and the pH of water is increased to 0.5 or more, such as in a water storage tank,
It is preferable to add 50 g or more of the present modifier to 1 m ^{3 of} water that requires modification. If the amount added is less than 50 g, the increase in pH will be insufficient. In addition, when the present regulator is used as a filling layer or a part of the material constituting the filling layer, SV
It is preferable to pass the water to be reformed at a water flow rate of 1 or more. When the SV is less than 1, the pH after passing water does not change so much and it is uneconomical.

[0027]

EXAMPLES Hereinafter, detailed description will be given with reference to examples.
The measurement items described in the examples were obtained by the following methods.

(Bulk Density) “Gakushin-shin 2 Method for Measuring Apparent Porosity, Apparent Specific Gravity and Bulk Specific Gravity of Magnesia Clinker” determined by the 124th Committee Test Method Subcommittee of the Japan Society for the Promotion of Science (1981, Refractories) The volume density was calculated by using the following calculation formula.

[0029]

[Equation 1]

(Powdering rate after 1 hour from the introduction into water) The sample was put in a metal basket having an opening of the same size as the minimum particle size of the sample.
The basket was slowly put into water, the basket was taken out after a lapse of one holding period, the sample remaining in the basket was dried, and the weight of the sample after drying was measured. The difference between the weight before the test and the weight after drying was taken as the amount peeled from the sample by pulverization, that is, the amount pulverized by pouring in water. The value obtained by dividing the difference (weight reduction amount) by the weight before the test was defined as the pulverization rate (%).

Examples 1 to 5 Five types of magnesia-based materials, which are the pH adjusters of the present invention, were prepared and immersed in seawater for 1 hour. Table 1 shows main constituent substance names, bulk densities, MgO contents, material particle sizes and pulverization rates.

[0032]

[Table 1]

Comparative Examples 1 and 2 Quick lime and sintered calcia clinker which are non-magnesium type materials
Was immersed in seawater for 1 hour as in Examples 1 to 5. Table 2 shows the results.

From these results, the powders of the magnesia-based materials of Examples 1 to 5 had a pulverization rate of 1 hour after being placed in water, and Comparative Examples 1 and 2
It was found that the amount was very small as compared with, and it was difficult to disintegrate into powder.

[0035]

[Table 2]

Example 6 A glass beaker containing 2 liters of seawater (pH 7.5) at a water temperature of 20 ° C. was used as a pH adjusting agent for the magnesium-based material of the present invention (heat treatment (sintering) at a temperature of 2000 ° C.). Synthetic sintered magnesia clinker (MgO content 98%, bulk density 3.4 g / cm
³ , particle size 1 to 4.75 mm)), and as a comparative sample, 200 g of shredded husks (particle size 1 to 10 mm) containing calcium carbonate as a main component, which is a conventional pH adjuster, respectively, are added.
The pH of seawater was measured daily. The change in pH of seawater is shown in FIG. From this result, the pH of the seawater in which the conventional pH adjuster, oyster shell, was added was around 7.9 even after 10 days, but when the magnesia-based material of the present invention was added, It exceeded pH 8 in about 30 minutes, exceeded pH 9.5 one day later, and remained around pH 10 after the third day. It was confirmed that the pH adjuster according to the present invention has an excellent ability to raise pH and can be maintained as compared with the conventional pH adjuster, that is, oyster shell.

Example 7 and Comparative Examples 3 to 312 312 flounders were released under the following three conditions in a concentrate tank containing 18 m ^{2 of} area and 0.6 m in height of seawater, and raised for 67 days. did. (1) Example 7: Sand and 500 kg of the same magnesia-based pH adjusting agent of the present invention as in Example 6 were sprayed on the bottom. (2) Comparative Example 3: The test was carried out with the concrete surface as it was without any damage on the bottom. (3) Comparative Example 4: Only the bottom was sanded. Table 3 shows the experimental results. As a result, in the experimental results using the magnesia-based material of the present invention, the number of mortality was smaller than that of the water tank in which other magnesia-based materials were not added, and the yield was improved. Etc., was confirmed to be effective.

[0038]

[Table 3]

Example 8 A glass column (diameter 24 mm, length 300 mm) was packed with 50 g (volume 25 cm ³ ) of the material of Example 1 and SV = 10.
Seawater (pH 8.0) was continuously flowed for 30 days at the water flow rate of, and the pH of the seawater after passing through the column was measured. The result is shown in FIG. The pH of seawater after the treatment always showed a value around 0.7 higher than that of the seawater before the treatment. No collapse of the material in the column was observed.

Comparative Example 5 With respect to the material of Comparative Example 1, a water flow experiment was conducted in the same manner as the experiment in Example 8. Quick lime exhibited a rapid exothermic reaction immediately after passing water, while strong alkaline seawater having a pH of 11 or more was discharged from the column. The quicklime disintegrated into powder and was discharged from the column out of the system. Therefore, the experiment was completed 30 minutes after the start.

From the results of Example 8 and Comparative Example 5, it was shown that the present magnesia-based material of Example 8 is more resistant to disintegration than quick lime, which is a conventional pH adjuster, and it has a strong alkalinity like quick lime. It was also confirmed that no water was produced.

Example 9 2 l of strongly acidic water having a temperature of 70 ° C and pH 1 was placed in a 3l glass beaker in a warm bath kept at 70 ° C, and the magnesia-based material used in Examples 1 and 8 was added thereto. 1 kg (volume 0.5 l) was charged, and the pH of the water deposited on the bottom of the material was measured while stirring the water on the top with a stirring force such that the material did not move.

Comparative Example 6 Using the same strongly acidic water of pH 1 as in Example 9 and the experimental method, 1 kg (volume 0.5 l) of limestone having a particle size of 1 to 9.52 mm was added and the pH was measured.

The changes in pH of Example 9 and Comparative Example 6 are shown in FIG.
Shown in In the case of the material of the present invention, water has a high pH rapidly after being charged.
After 1 hour, the pH exceeded 3 and pH exceeded 6 after 6 hours. The limestone of Comparative Example 6 increased to about pH 2.0 after being charged, but after that, it did not change and maintained strong acidic water. It was confirmed that the magnesia-based material is also effective for increasing the pH of strongly acidic water.

Example 10 Magnesite, which is a naturally occurring magnesia-based ore, was heated at a temperature of 950 ° C.
After heat treatment and cooling to room temperature, it is crushed to a particle size of 1-4.75 mm
Screened. The results of evaluation of this magnesia-based material in the same manner as in Examples 1 to 5 are shown in Table 4, and the water temperature was 20 ° C. and p
30 g of this material was added to 1 liter of H7.9 seawater, and the pH was measured by the same method as in Example 9. The results are shown in FIG.

Example 11 Magnesite ore having a grain size of 9.52 mm or more is calcined by using an electric furnace at a temperature of 900 ° C. for 30 minutes, calcined, cooled to room temperature, and ground to a powder of 0.1 mm or less. did. When the constituent minerals of the obtained calcined product were identified by powder X-ray diffraction method,
In addition to periclase (magnesium oxide), undecomposed magnesite (magnesium carbonate) was found. The powder was made into a columnar molded product at a pressure of 392 MPa, and this was crushed to obtain a crushed product having a particle size of 1 to 4.75 mm. Table 4 shows the results of testing the crushed product by the same evaluation method as in Example 10. Also, as in Example 10, p after being added to seawater
When H was measured, it was slightly lower than the rate of increase in pH of Example 10 until 1 hour immediately after the start of the experiment, but thereafter, almost the same pH value was shown.

From Examples 10 and 11, even when a natural magnesia-based ore is heat-treated at a temperature of decomposition temperature or higher, it does not disintegrate even if it is put into water, and it has an effect of increasing the pH of water. Was confirmed.

[0048]

[Table 4]

Example 12 Magnesium hydroxide powder was molded under a pressure of 588 MPa,
After crushing, it was sieved to 1 to 4.75 mm to obtain a material having a bulk density of 2.4 g / cm ³ . Table 5 shows the MgO content and pulverization rate of this material.
When 20 g of this material was added to 1 liter of seawater having a water temperature of 25 ° C. and a pH of 7.6, the pH of the seawater increased without disintegrating and dispersing. The transition of pH is shown in FIG.

Example 13 3% of magnesium salt was added to magnesium hydroxide powder, homogeneously mixed, molded at a pressure of 196 MPa, crushed and crushed to obtain a bulk density of 1.8 g / cm ³ having a particle diameter of 1 to 4.75 mm and a magnesia system. Got the material. This was left at 30 ° C. for 30 days. MgO of this material
The content rate and the pulverization rate are shown in Table 5 as in Example 12. Furthermore, as in Example 12, 20 g of this material was added to 1 liter of seawater having a water temperature of 20 ° C. and a pH of 7.6, and the pH was measured. The pH of the seawater suddenly increased to high immediately after the addition, reached pH 9 after 2 hours, and thereafter, a very gentle rising curve was drawn. No disintegration of this material was observed after it was placed in seawater.

From Examples 12 and 13, it was also confirmed that even a granulated product mainly composed of magnesium hydroxide has an effect of increasing the pH of water without disintegrating after being poured into water.

[0052]

[Table 5]

[0053]

As described above, when the hardly-disintegrating magnesia-based pH adjusting agent of the present invention is administered to water and sediment having a lowered pH, it can be poured into water rather than the conventional lime-based pH adjusting agent. It was found that it is difficult to disintegrate and has the effect of increasing the pH for a long period of time. It was also found that the pH adjusting ability was superior to that of the conventional lime-based pH adjusting agent. Furthermore, it was confirmed that the addition of this material improves the yield and the like of the organisms cultivated. Therefore, in improving the habitat of fish and aquatic organisms, p is more efficient than conventional pH adjusters.
It was recognized that it is possible to adjust H.

[Brief description of the drawings]

FIG. 1 is a diagram showing a change over time in pH transition in Example 6 of the present invention.

FIG. 2 is a diagram showing a change with time of pH transition in Example 8 of the present invention.

FIG. 3 is a diagram showing a change with time of pH transition in Example 9 of the present invention and Comparative Example 6.

FIG. 4 is a diagram showing a change with time of pH transition in Example 10 of the present invention.

FIG. 5 is a diagram showing a change with time of pH transition in Example 12 of the present invention.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kunio Watanabe 1985, Kozugushi, Ube City, Yamaguchi Prefecture Ube Chemical Industry Co., Ltd.

Claims (8)

[Claims] 1. A powder composed of one or two or more materials of a magnesia type material, and having a pulverization rate of 1 hour after being placed in water for 1 hour.
A non-disintegrating magnesia-based pH adjuster for improving water quality and bottom sediment, which is 0% or less. 2. The hardly-disintegrating magnesia-based pH adjusting agent for improving water quality and bottom sediment according to claim 1, wherein the pH adjusting agent has a bulk density of more than 2.3 g / cm ³ . 3. The hard-to-disintegrate magnesia for improving water quality and bottom sediment according to claim 1 or 2, wherein the magnesia-based material is one or more magnesium oxide-based materials heated at 1000 ° C. or higher. System pH adjuster. 4. The hardly-disintegrating magnesia-based pH adjusting agent for improving water quality and bottom sediment according to claim 1, wherein the magnesia-based material is a material obtained by heat-treating naturally occurring magnesia-based ore at a decomposition temperature or higher. . 5. The hardly-disintegrating magnesia-based pH adjuster for improving water quality and bottom sediment according to claim 1, wherein the magnesia-based material is a molded product of magnesium-based compound powder or a crushed product thereof. 6. A reforming target area 1 m ² per a high pH reduction, p
The pH of the pre-reforming pH can be increased by 0.5 or more by adding 1 kg or more of the H-adjusting agent, and the water-resistant and bottom sediment-improving disintegration according to claim 1-5. Magnesium based pH adjuster. 7. The pH per m ^{3 of the} water to be reformed for increasing the pH
The disintegration property for improving water quality and bottom sediment according to claim 1, wherein the pH can be increased by 0.5 or more from the pH before reforming by spraying 50 g or more of the regulator. Magnesium-based pH adjuster. 8. An SV in a packed bed composed of a pH adjusting agent.
It is possible to raise the pH by 0.5 or more than the pH before the reforming by passing water at a rate of = 1 or more. Magnesium-based pH adjuster.