JPH06304409A - Green algae treatment agent and treatment method - Google Patents

Abstract

PURPOSE:To efficiently precipitate and remove green algae by providing a green algae treatment agent which consists of an acid together with a water-soluble aluminum salt or a water-soluble iron salt as effective components and specifying the composition of the agent with a certain range of the components ratio. CONSTITUTION:A treatment agent containing an acid together with a water-soluble aluminum salt or a water-soluble iron salt as effective components with the componental ratio; 3.4<H/M<40 (wherein H stands for the moles of hydroxide ion necessary for neutralization of the agent and M for moles of aluminum or iron) is added to water containing green algae in a range of 0.02-0.12mmol/l in terms of aluminum or iron to carry out flocculation. By keeping the resulting liquid treated for flocculation still, precipitation of the flocks is done well and even fine residues are scarcely left. The concentration of the supernatant liquid can be as low as 0.5 or lower and thus the load to the succeeding filtration process can be lessened and efficient water purifying treatment can be carried out. Meanwhile, the flocculated liquid is easy to be separated and even if it is filtered as it is, treated water is obtained with high removal efficiency of the flocculated matters.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION This invention is called Aoko.
The present invention relates to a treatment agent for water containing a large amount of cyanobacterial microcystis and a treatment method.

[0002]

2. Description of the Related Art In recent years, blue-green algae have been generated due to eutrophication of lakes and marshes, and their removal has become an issue. In particular, the blue-green alga Microcystis that composes water-bloom abundantly occurs from summer to autumn, causing many water purification disorders. When water-bloom occurs, the turbidity of the water is 10-2 when it is high.
It reaches 0 degrees. The turbidity standard of drinking water is 2 degrees, and in order to obtain drinking water from this water, it is required to remove 80 to 90% or more in terms of turbidity.

Generally, as a method for removing suspended solids from water, a method in which a flocculant is first added, flocculation and sedimentation are carried out, and then residual suspended matter in the supernatant is removed by filtration is adopted.

According to a report on the Sagami Lake system (Page 167 of the 37th Water Supply Research Presentation in 1986), when a large amount of microcystis is generated, the number of cells in the raw water is about 10,000 cells / ml or more. , The precipitation removal rate is 70 in normal treatment
%, The turbidity of the treated water can be reduced only to 1-2 degrees. On the other hand, in the jar test test, which can predict the precipitation removal rate, pack (polyaluminum chloride)
It is said that a high removal rate can be obtained by adding more than twice (0.2 mmol / l in terms of aluminum as 100 ppm of pack). However, this method cannot be adopted because it increases the load of the filtration process in the subsequent process.

When a large amount of microcystis is generated, its size is distributed from a single cell of 2-3 microns to a colony of 100 microns or more and has gas bubbles, so that it is not a conventional flocculating agent for clay-based colloids. The sedimentation is poor and it is difficult to remove. Although the current drinking water standard is turbidity of 2 degrees or less, cyanobacteria emit toxicity and odor.
It is desirable to remove the precipitate as much as possible.

As a countermeasure, many methods have been proposed as follows. 1. Method of stopping pre-chlorination and adding inorganic coagulant twice. Method of floating separation by using a large amount of inorganic coagulant. Method using biological flocculant 4. However, it is difficult to say that any of these methods can efficiently remove high-concentration blue-green algae, and many obstacles still occur.

That is, regarding the removal of high-concentration water-bloom, page 164 of the 37th Water Supply Research Presentation Material (Showa 6
According to (1 year), the precipitation removal rate is about 30% in the normal coagulation treatment, but the precipitation removal rate is about 7% due to the discontinuation of pre-chlorination.
It was improved to 0%. Furthermore, in order to improve the removal rate in the filtration process, a second coagulant is added (called a two-stage coagulation method).
After that, through a filtration process, a removal rate of 95% is finally obtained. However, in this case, the clogging in the filtration process was more severe than usual, and the filtration duration was halved.

JP-A-63-179809 proposes a water-soluble aluminum salt as a blue-green processing agent. The method is to add a larger amount of inorganic coagulant than usual (water-soluble aluminum salt is calculated as 0.2 to 0.8 mm in terms of aluminum).
ol / l), and the floating separation is performed. In this method, the water-bloom aggregates largely and floats up as flocs with a large amount of coagulant. According to the embodiment, the removal rate is 60-
Although it is 89%, the turbidity of the treated water is a high value of 5 degrees or more. The residual turbidity and the floating flocs are too heavy to be loaded in the usual filtration and dehydration processes, and the system is limited. Generally, when the amount of the aggregating agent added is large, the resulting aggregated particles have a poor sedimentation property and the sludge has a poor dewatering property, which makes the treatment difficult.

[0009] Despite the above improvement efforts, the treatment of water-bloom has not been solved yet. For example, Water Supply Association magazine 5
It is reported in Volume 9, No. 3, p. 30 (1992) that a large amount of algae causes an obstacle to water purification treatment. That is, 1) Algae have poor cohesiveness, and some of them do not settle and remain in the liquid, resulting in poor precipitation removal rate. 2)
It has been reported that the unprecipitated residue causes filtration leakage, clogging, and filtration blockage in the next filtration step, and 3) a two-stage aggregation treatment may be necessary.

As described above, the problem of the conventional technique is that the aggregation and precipitation are insufficient, and a large amount of the untreated residue is left in the treatment liquid. Therefore, how to remove a small amount of coagulant and to obtain a high precipitation removal rate is a subject of the water-bloom treatment.

[0011]

[Problems to be Solved by the Invention] By adding a small amount of metal ion (about 0.1 mmol / l or less) from water containing water-bloom (mainly containing a large amount of microcystis),
It is an object of the present invention to provide a treating agent capable of precipitating and removing water-bloom and a treating method using the treating agent.

Means for Solving the Problems [0012] In order to achieve this object, the inventors of the present invention examined natural water of Lake Suwa, Kasumigaura, and Tenryu River as raw water in a jar test, and found that it contained a large amount of microcystis. If water is treated with a small amount of inorganic coagulant as before, some of the water-blooms will not grow into appropriate flocs (aggregates of flocculate and coagulant) and will remain as fine particles. It was observed to float inside.

It was presumed that this fine water-bloom made it difficult to remove, and as a result of further investigation, a liquid containing a metal component and an acid was added to the raw water. Then, it was found that the water-bloom had a good sedimentation property and had a very small amount of fine residue, and thus the present invention was achieved.

That is, the invention of the coagulation treatment agent of Aoko is as follows.
An acid and a water-soluble aluminum salt or a water-soluble iron salt are used as active ingredients, and the component ratio (molar ratio) is 3.4 <H /
The composition is in the range of M <40 (where H represents the number of moles of hydroxide ions required to neutralize the present treatment agent, and M represents the number of moles of aluminum or iron), It is a coagulant treatment agent for Aoko.

The invention of the method for treating water-bloom has an acid and a water-soluble aluminum salt or a water-soluble iron salt as active ingredients, and the component ratio (molar ratio) is 3.4 <H / M <4.
0 (however, H indicates the number of moles of hydroxide ion required to neutralize the present treatment agent, M indicates the number of moles of aluminum or iron), and the treatment solution containing aluminum contained in the water. Or 0.02 to 0.12m in terms of iron
The gist is that it is added at a ratio in the range of mol / l and aggregating treatment is performed.

In the constitution of the present invention, the same effect can be obtained by directly adding the active ingredients of the treating agent to the water.

The amount of the treating agent added gives an optimum flocculating effect when the treating solution has a pH of 6 to 7.

[0018]

In general, when a large amount of water-bloom is generated due to eutrophication, the pH of the water for use increases. Due to photosynthesis during the daytime, the pH often exceeds 9, and at night it drops slightly. However, due to the mixing of rivers etc.
There is also water that has an H of 8 or less. The "water containing water-bloom" of the present invention includes both of them, but both are intended for water containing a large amount of microcystis (several thousands / ml or more). These water is COD due to blue water
(Chemical oxygen demand) is also high and often shows 5 ppm or more.

The present invention is based on the finding that microcystis efficiently aggregates when a mixture of a flocculant and an acid is added to such water.

The aggregating treatment agent of the present invention contains a large amount of acid component, and by simply adding a small amount to water containing water-bloom, mixing and stirring, the pH of the water is appropriately lowered, and water-bloom has a good sedimentation property. A flocculation treatment liquid that grows into flocs and has a small amount of fine residue can be easily obtained. The amount of the treating agent added in this case is 0.02 to 0.
A ratio in the range of 12 mmol / l is sufficient.

When the water containing water-bloom is treated according to the treatment method of the present invention, a good coagulation treatment liquid can be obtained.
At this time, a similar flocculation treatment liquid can be obtained by separately adding an acid as an active ingredient and a water-soluble aluminum salt or iron salt depending on the pH of the water and the degree of flocculation.

PH of the coagulation treatment liquid in the present invention
Shows an optimum aggregation state when 6 to 7 is exhibited, and the effect is exhibited even with a small amount of the treatment agent added.

When the coagulation treatment liquid obtained in the present invention is allowed to stand, the floc sedimentation property is good and the fine residue is small, so that the turbidity of the supernatant can be as low as 0.5 ° C. or less. The load can also be reduced.

[0024]

SUMMARY OF THE INVENTION The present invention relates to an efficient coagulating agent for water-bloom and a method for treating it with the agent.

First, the constituents of the agent for coagulation treatment of blue-green alga containing the acid and the water-soluble aluminum salt or water-soluble iron salt of the present invention as the active ingredient will be explained. The acid used in the present invention may be an organic acid, but it is industrially preferably an inorganic acid such as sulfuric acid, hydrochloric acid or carbonic acid.

The water-soluble aluminum salt or water-soluble iron salt is one or two selected from aluminum salts such as aluminum sulfate and basic aluminum chloride, and iron salts such as ferric sulfate and ferric chloride. The above mixture is referred to. These salts are generally used as an inorganic flocculant and are industrially produced and easily available compounds.

Secondly, the reason for limiting the component ratio of the aggregating treatment agent of the present invention will be explained. The compositional composition ratio of the coagulation treatment agent for blue-green alga that contains an acid and a water-soluble aluminum salt or a water-soluble iron salt as active ingredients is limited to the following range (molar ratio).

3.4 <H / M <40 (where H is the number of moles of hydroxide ion required to neutralize the treatment agent, M
Indicates the number of moles of aluminum or iron. )

When the component ratio H / M is smaller than 3.4,
The composition is close to that of the composition containing no acid (for example, aluminum sulfate has this ratio of 3), and like the conventional product, the coagulation ability is lowered, and the treatment agent has a large amount of unremoved water-bloom or floating components.

When the component ratio H / M is more than 40, the acid component becomes excessive and the aggregating effect is poor, or the pH of the aggregating treatment solution is excessively lowered and the pH is required to be adjusted after the treatment. .

Thirdly, a method for preparing the coagulation treatment agent of the present invention will be described. An acid and a water-soluble aluminum salt or a water-soluble iron salt are used as active ingredients, and the component ratio (molar ratio) thereof satisfies the range of 3.4 <H / M <40.
The aggregating treatment agent of the present invention can be produced by preparing an aluminum-containing acidic recovery liquid such as that of Aluminum Sash Industry Co., Ltd. based on a method other than the method of mixing each with a liquid or powder to form a solution.

However, when the water-blowing agent of the present invention is prepared in advance, a combination in which the acid and the coagulant do not react to cause precipitation is desirable for storage. For example, sulfuric acid and aluminum sulfate, hydrochloric acid and polyaluminum chloride, and the like.

Fourthly, the processing method of the blue-green alga of the present invention will be explained. When the water-containing water-blowing agent containing the water-bloom aggregating agent of the present invention is added and mixed at the same injection position as in the conventional case,
Blue water efficiently aggregates.

At this time, the necessary addition amount to the water for use depends on the concentration of water-bloom in the raw water, but it is converted to metal ion of the water-soluble aluminum salt or water-soluble iron salt as the active ingredient, and per 1 liter of water used. The range of 0.02 to 0.12 mmol (0.5 to 3 mg / l as aluminum in the case of a treating agent containing polyaluminum chloride as an active ingredient) is desirable.

If the addition amount is 0.02 mmol / l or less, the aggregating treatment agent becomes insufficient. This addition amount is 0.13m
If it is more than mol / l, the amount of flocs produced becomes excessive, which adversely affects the subsequent steps.

According to the treatment method of the present invention, the effect is exhibited in a wide range of pH of coagulated treated water from 8 to 5,
The effect is particularly remarkable when H is in the range of 7 to 6.

When the coagulation treatment agent of the present invention is added to water, the active ingredients can be separately injected. In this case, it is more effective to add the acid component first and then add the aluminum salt or iron salt.

[0038]

EXAMPLES The present invention will be described in more detail by way of examples. The treatment effect of water-bloom was determined by using a jar test. The conditions are as follows. (Jar test conditions) Put 1 liter of raw water containing water-bloom into a beaker,
Add an aggregating treatment agent, stir and allow to stand, and measure the turbidity of the supernatant. Rapid stirring 100 rpm, 1 minute Slow stirring 60 rpm, 10 minutes Static 10 minutes

Examples 1 and 2 The blue-green alga treating agent of the present invention was prepared in advance, and the blue-green alga was treated in the Jatest test. (1) Preparation of a flocculating agent Polyaluminum chloride (alumina content: 10 ml) was added to 10 ml of pure water.
%) 48 mg and hydrochloric acid were added to prepare the following two types of treating agents. Treatment agent A Aluminum content 0.1 mmol Acid component amount 0.62 mmol H / M = 6.4 Treatment agent B Aluminum content 0.1 mmol Acid component amount 0.68 mmol H / M = 7.0

(2) Coagulation treatment of water-bloom The surface water of Lake Suwa in the middle of September was sampled, and the water-bloom was treated with the treatment agent prepared above. Raw water quality pH 8.6 Turbidity 36 degrees Alkalinity 46 ppm (Example 1) Jar test and its results Treatment agent A was added in total amount Water temperature 24 degrees Supernatant turbidity 1.9 degrees Turbidity removal rate 95% Treatment solution pH 6 .8

(Example 2) Jar test and its result The total amount of the treating agent B was added. Water temperature 24 ° C Supernatant turbidity 0.7 ° Turbidity removal rate 98% Treatment liquid pH 6.4

As shown in the examples, a high removal rate was obtained. For comparison, the same treatment was carried out using only polyaluminum chloride, but the supernatant turbidity was 2 degrees or more, and the removal rate was low.

(Comparative Example 1) Treatment agent Polyaluminum chloride 48 mg Aluminum content 0.1 mmol Acid component amount 0.13 mmol H / M = 1.4 (treatment result) Supernatant turbidity 6.4 degrees Turbidity removal rate 82% Treatment liquid pH 7.3

Examples 3 and 4 The compositions of the raw water and the treating agent were the same as in Examples 1 and 2, but the components of the treating agent were separately added to the raw water for treatment. (1) Aggregation treatment agent Polyaluminum chloride (containing 10% alumina) 48 m
g and hydrochloric acid were combined. Treatment agent A Aluminum component amount 0.1 mmol Acid component amount 0.62 mmol H / M = 6.4 Treatment agent B Aluminum content 0.1 mmol Acid component amount 0.68 mmol H / M = 7.0

(2) Coagulation treatment of water-bloom First, hydrochloric acid was added, and then polyaluminum chloride was added. (Example 3) Jar test and its result Treatment agent Combination A Water temperature 24 degrees Supernatant turbidity 1.7 degree Turbidity removal rate 95% Treatment solution pH 6.8

(Example 4) Jar test and its results Treatment agent Combination B Water temperature 24 degrees Supernatant turbidity 0.5 degree Turbidity removal rate 99% Treatment solution pH 6.4

As shown in the examples, when the removal rate was high and the sedimentation was good, the turbidity of the supernatant reached 0.5 degrees.

Example 5 The water-bloom treating agent of the present invention was prepared in advance, and the water-bloom was treated in the Jatest test. (1) Preparation of Aggregation Treatment Agent The following treatment agent was prepared by adding 16 mg of aluminum sulfate (containing 8% alumina) and sulfuric acid to 10 ml of pure water. Treatment agent C Aluminum content 0.025 mmol Acid component amount 0.38 mmol H / M = 15

(2) Coagulation treatment of water-bloom The surface water of Lake Suwa at the end of October was sampled and the water-bloom was treated with the treatment agent prepared above. Raw water quality pH 7.3 Turbidity 13 degrees Alkalinity 41ppm COD 5ppm Jar test and its results Treatment agent C was added in total amount Water temperature 16 degrees Supernatant turbidity 1.5 degree Turbidity removal rate 89% Treatment solution pH 6.3

As shown in the examples, a high removal rate was obtained. For comparison, the same treatment was carried out using only aluminum sulfate, but the supernatant turbidity was 2 degrees or more, and the removal rate was low.

(Comparative Example 2) Treatment agent Aluminum sulfate 16 mg Aluminum content 0.025 mmol Acid component amount 0.08 mmol H / M = 3 (Treatment result) Supernatant turbidity 6.3 degrees Turbidity removal rate 52% pH 6.9 The treatment agent of the present invention is effective even though the raw water at October has a considerably reduced amount of microcystis.

Example 6 The pH of raw water was adjusted with the acid of the treating agent of the present invention, and then aluminum or iron was added. (1) Aggregation treatment agent Treatment agent D 11 mg of sulfuric acid and 48 mg of polyaluminum chloride were combined. Aluminum content 0.1 mmol Acid component amount 0.35 mmol H / M = 3.5 Treatment agent E Ferric chloride 8.6 mg and sulfuric acid 32 mg were combined. Iron content 0.053 mmol Acid component amount 0.79 mmol H / M = 15

(2) Coagulation treatment of water-bloom The surface water of Lake Suwa in the beginning of September was sampled and the water-bloom was treated with the treatment agent prepared above. Raw water quality pH 9.3 Turbidity 9.6 degrees Alkalinity 42ppm

(Example 6) Jar test and its result Treatment agent Combination D First, sulfuric acid was added to adjust the pH of raw water to 7.5, and then,
Polyaluminum chloride was added. Water temperature 24 degrees Supernatant Turbidity 0.7 degrees Turbidity removal rate 93% Treatment liquid pH 6.9

Example 7 Jar Test and Results Treatment Agent Combination E First, sulfuric acid was added to adjust the pH of raw water to 6.0, and then
Ferric chloride was added. Water temperature 24 degrees Supernatant turbidity 1.0 degree Turbidity removal rate 90% Treatment liquid pH 5.5

For comparison, using ferric chloride alone,
The same treatment was carried out, but the supernatant turbidity was 2 degrees or more, and the removal rate was low. (Comparative Example 3) Treatment agent Aluminum content 0.053 mmol Acid component amount 0.16 mmol H / M = 3 (Treatment result) Supernatant turbidity 7.3 degrees Turbidity removal rate 24% Treatment solution pH 7.7

Examples 8 and 9 Carbon dioxide and acetic acid were combined with polyaluminum chloride as the acid component of the treating agent of the present invention, and they were separately added to raw water for treatment. (1) Agglomeration treatment agent Treatment agent G 48 mg of polyaluminum chloride (alumina content 10%) was combined with carbon dioxide gas. Aluminum component amount 0.1 mmol Acid component amount 0.4 mmol H / M = 4 Treatment agent H Polyaluminum chloride (alumina content 10%) 48 mg and acetic acid were combined. Iron content 0.1 mmol Acid component amount 0.42 mmol H / M = 4.3

(2) Coagulation treatment of water-bloom Kasumigaura surface water was collected at the end of July, and water-bloom was treated with the treatment agent prepared above. Raw water quality pH 8.7 Turbidity 19 degrees Alkalinity 53ppm

(Example 8) Jar test and its results First, carbon dioxide gas was blown in, and then polyaluminum chloride was added. Treatment agent Combination G Water temperature 23 degrees Supernatant turbidity 0.5 degree Turbidity removal rate 97% Treatment solution pH 6.6

Example 9 Jar Test and Results First, acetic acid was added, followed by polyaluminum chloride. Treatment agent combination H Water temperature 23 degrees Supernatant turbidity 0.2 degree Turbidity removal rate 99% pH of treatment solution 6.4

For comparison, the same treatment was carried out using only polyaluminum chloride, but the supernatant turbidity was 2 degrees or more, and the removal rate was low. (Comparative Example 4) Treatment agent Aluminum content 0.1 mmol Acid component amount 0.14 mmol H / M = 1.4 (Treatment result) Supernatant turbidity 6.7 degrees Turbidity removal rate 65% Treatment solution pH 7.4

[0062]

EFFECTS OF THE INVENTION The agent for coagulating blue-green alga of the present invention can be manufactured at low cost from commercially available chemicals which are easily available. Moreover, since this treatment agent has good dilution stability, accurate injection is possible by dilution injection even in a small-scale apparatus.

On the other hand, according to the treatment method of the present invention, a coagulation treatment liquid having a good sedimentation property and a small amount of fine suspended matter can be obtained from water containing a large amount of microcystis.

If this coagulating liquid is left to stand, a high precipitation removal rate can be obtained. According to this method, for many water,
The supernatant turbidity easily falls below 1 degree. Therefore, if this supernatant liquid is filtered, there will be less filtration leakage and filtration load,
Efficient water purification treatment is possible.

Further, this coagulation liquid is easily separated later, and the treated water can be obtained with a high removal rate even if it is filtered as it is.

[Procedure amendment]

[Submission date] March 25, 1994

[Procedure Amendment 1]

[Document name to be amended] Statement

[Correction target item name] 0052

[Correction method] Change

[Correction content]

Examples 6 and 7 The pH of raw water was adjusted with the acid of the treating agent of the present invention, and then aluminum or iron was added. (1) Aggregation treatment agent Treatment agent D 11 mg of sulfuric acid and 48 mg of polyaluminum chloride were combined. Aluminum content 0.1 mmol Acid component amount 0.35 mmol H / M = 3.5 Treatment agent E Ferric chloride 8.6 mg and sulfuric acid 32 mg were combined. Iron content 0.053 mmol Acid component amount 0.79 mmol H / M = 15

[Procedure Amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0056

[Correction method] Change

[Correction content]

For comparison, using ferric chloride alone,
The same treatment was carried out, but the supernatant turbidity was 2 degrees or more, and the removal rate was low. (Comparative Example 3) Treatment agent Ferric chloride 8.6 mg Iron content 0.053 mmol Acid component amount 0.16 mmol H / M = 3 (treatment result) Supernatant turbidity 7.3 degree Turbidity removal rate 24% Treatment liquid PH of 7.7

[Procedure 3]

[Document name to be amended] Statement

[Correction target item name] 0060

[Correction method] Change

[Correction content]

Example 9 Jar Test and Results First, acetic acid was added, followed by polyaluminum chloride. Treatment agent combination H Water temperature 23 degrees Supernatant turbidity 0.2 degree Turbidity removal rate 99% pH of treatment solution 6.4

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0061

[Correction method] Change

[Correction content]

For comparison, the same treatment was carried out using only polyaluminum chloride, but the supernatant turbidity was 2 degrees or more, and the removal rate was low. (Comparative Example 4) Treatment agent Aluminum content 0.1 mmol Acid component amount 0.14 mmol H / M = 1.4 (Treatment result) Supernatant turbidity 6.7 degrees Turbidity removal rate 65% Treatment solution pH 7.4 Next In addition, the treatment agent of the present invention and a conventional flocculant were added to the treated p
A comparative test was conducted under the same H conditions. Example 10 (1) Preparation of aggregation treatment agent 20 mg of aluminum sulfate (containing 8% alumina) and sulfuric acid were added to 10 ml of pure water to prepare the following treatment agent. Treatment agent F Aluminum content 0.031 mmol Acid component amount 0.19 mmol H / M = 6.1 (2) Algae coagulation treatment In mid-August, water was sampled from the surface layer of Lake Suwa, where water-bloom had begun to occur, and the preparation was performed. The jar test was carried out using the treating agent. Water quality of raw water Blue water was finely suspended in water and did not grow enough to float on the surface, but COD reached 3 ppm. For pH6.7 comparison pH7.4 turbidity 11 ° alkalinity 31ppm water temperature 22 ° C. jar test and its result processing agent F the total amount added supernatant turbidity 0.6 degrees turbidity removal rate 95% treatment solution, aluminum sulfate Using only the same p
A comparative test was conducted by increasing the amount added so as to reach H. (Comparative Example 5) Treatment agent Aluminum sulfate 30 mg Aluminum content 0.047 mmol Acid component amount 0.14 mmol H / M = 3 (Treatment result) Supernatant turbidity 1.1 degree Turbidity removal rate 90% Treatment solution pH 6.7 Thus, in the comparative example, the pH after the treatment was the same as in Example 10.
However, the treatment agent of the present invention remains
The turbidity showed a double effect.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Minoru Tanaka 2 Daimei Chemical Industry Co., Ltd. 3685 Minamiminowa Village, Kamiina-gun, Nagano Prefecture

Claims (3)

[Claims] 1. An acid and a water-soluble aluminum salt or a water-soluble iron salt as active ingredients, and the component ratio (molar ratio) thereof.
From 3.4 <H / M <40 (where H is the number of moles of hydroxide ion required to neutralize the treatment agent, and M is the number of moles of aluminum or iron). A coagulation treatment agent for blue-green alga. 2. An acid and a water-soluble aluminum salt or a water-soluble iron salt as active ingredients, and the component ratio (molar ratio) thereof.
In the range of 3.4 <H / M <40 (where H represents the number of moles of hydroxide ion required to neutralize the treatment agent, and M represents the number of moles of aluminum or iron). To
A method for treating water-bloom, which comprises adding to water containing water-bloom at a rate of 0.02 to 0.12 mmol / l in terms of aluminum content or iron content and performing coagulation treatment. 3. The method for treating water-bloom according to claim 2, wherein the active ingredient of the treatment agent is separately added to water containing water-bloom.