JPH10165825A - Cleaning agent for contaminated waste water - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simultaneously decompose and remove not only SS in a contaminated waste water but also contaminants which are dissolved and present in a contaminated waste water. SOLUTION: This cleaning treating agent is produced by compounding 30 to 50 pts.wt. of aluminum sulfate, 5 to 10 pts.wt. of aluminum chloride and 20 to 40 pts.wt. of alkali metal carbonate into 100 pts.wt. or the main component. The main component consists of 30 to 50wt.% natural mineral essentially comprising alumina silicate, 45 to 65wt.% calcium sulfate, and 1 to 5wt.% org. flocculant.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a purification agent for polluted effluent, and more particularly, it is dissolved in effluent regardless of whether the effluent to be treated is organic or inorganic. For example, dissolved pollutants such as metals and suspended suspended solids (SS) can be sedimented and separated at the same time. As a result, the polluted wastewater can be purified and converted into treated water of excellent quality. The present invention relates to a novel pollutant treatment agent for polluted wastewater.

[0002]

2. Description of the Related Art Conventionally, polluted wastewater is treated by adding various inorganic coagulants and / or organic coagulants to the wastewater to coagulate SS in the wastewater into sludge, and then treating the sludge with the sludge. Separated with water. Then, the treated water is discharged after being adjusted in pH, for example, so as to satisfy a predetermined water quality standard, and the separated sludge is dewatered, solidified, and discarded.

[0003] The main purpose of the flocculant used at this time is to effectively flocculate SS in the waste water, regardless of whether it is an inorganic flocculant or an organic flocculant.
Therefore, when a coagulant is introduced into a polluted wastewater in which metals such as Cr, Pb, and Cd are dissolved, some of these metals are separated while being surrounded by SS sludge. In addition, the added flocculant itself does not have the ability to fix and separate these metals, so that these dissolved pollutants cannot be effectively removed. That is, another treatment system is required to remove the dissolved pollutants in the polluted wastewater.

[0004] Separated sludge obtained by conventional wastewater treatment is generally easily soluble in water. Therefore, when the above-mentioned metals and the like are contained in the separated sludge, these dissolved pollutants are re-eluted from the separated sludge, which may cause new environmental pollution.

[0005]

SUMMARY OF THE INVENTION It is an object of the present invention to provide a powder purification agent which can solve the above-mentioned problems in the conventional treatment of polluted wastewater. Specifically, the polluted wastewater can be separated into sludge and clean treated water in a very short time, and even if the polluted wastewater is acidic or alkaline, it has a purification treatment capacity, and Since the treated water is neutral, it is not necessary to adjust the pH of the treated water as in the past, and simultaneously realize the fixation / separation of the dissolved pollutants in the polluted wastewater and the coagulation / separation of SS. It is another object of the present invention to provide a novel purification treatment agent for polluted effluent, in which separated sludge is stable and hardly soluble in water, so that re-elution of pollutants can be suppressed.

[0006]

In order to achieve the above-mentioned object, the present invention relates to a method for producing natural minerals mainly composed of alumina and silicate in an amount of 30 to 50% by weight and calcium sulfate 45.
Aluminum sulfate, 30 to 50 parts by weight per 100 parts by weight of the main component consisting of
1 part by weight, 5 to 10 parts by weight of aluminum chloride, and 20 to 40 parts by weight of an alkali metal carbonate are provided.

[0007]

BEST MODE FOR CARRYING OUT THE INVENTION The purification agent of the present invention comprises a natural mineral mainly composed of alumina and silicate, calcium sulfate and an organic coagulant as main components. Then, aluminum sulfate, aluminum chloride, and alkali metal carbonate are further blended as essential components with this main component.

First, alumina / silicon in the above main component
Natural minerals mainly composed of acid salts include, for example,
Lonite (Al_5/3Mg_1/3Si_FourO_Ten(OH)_TwoW_1/3・ M
H_TwoO), pyrophyllite (Al_TwoSi_FourO_Ten(O
H)_Two), Kaolinite (Al_TwoSi_TwoO_Five(OH)_Four),Halo
Isite (Al_TwoSi_TwoO_Five(OH)_Four), Sericite (K
_1.0(H _ThreeO)_1.0Al_Four(SiAl)₈O₂₀(OH)_Four), Masco
Knight (KAl_Two(OH)_Two[Al / Si_ThreeO_Ten]), Parago
Knight (NaAl_Two(OH)_Two[Al / Si_ThreeO_Ten])
I can give it. Each of these natural minerals alone
They may be used, or two or more kinds may be used as a mixture.

This natural mineral is considered to exhibit the following effects. That is, alumina and silicate, which are the main components of these natural minerals, are amphoteric compounds. When they come into contact with polluted wastewater, they are initially suspended in the polluted wastewater and then dissolved over time. As the dissolution proceeds, the polluted wastewater exists as a cation when it is in an acidic region and as an anion when it is in an alkaline region, and exhibits its own ion exchange ability. Therefore, for dissolved pollutants such as metals and cyanide and organometallic components dissolved in the polluted wastewater, for example, in the form of ions,
It exerts the effect of sorbing and fixing them. And
At the same time as the dissolution proceeds, the polymer itself becomes polymerized, and separation from the polluted wastewater proceeds.

[0010] These natural minerals also contain a wide variety of mineral trace elements (mineral components), and these mineral components elute with time in polluted wastewater. When water-soluble organic substances are present in the polluted wastewater, the eluted mineral components act on dissolved oxygen and dissociated acid ions in the wastewater that oxidize and decompose the organic substances, and some of them become salts. Combines with the organic substance, thereby converting the water-soluble organic substance into a solid which is hardly soluble in water, thereby promoting the separation of the organic substance component. Further, the re-elution in the separated sludge is suppressed. The above-mentioned effects of the mineral component are particularly useful for treating polluted wastewater containing organic matter whose decay has progressed.

The above-mentioned effect of the natural mineral is effectively exhibited in the range of pH of the polluted wastewater in the range of 3 to 9, that is, in any of the acidic region, the neutral region and the alkaline region. Next, as the calcium sulfate constituting the main component,
Specifically, gypsum can be given. Examples of the gypsum include one type such as dihydrate gypsum, hemihydrate gypsum, and anhydrous gypsum, or a mixture thereof.

The calcium sulfate is suspended in the polluted waste water or, although very slow, a part of the calcium sulfate is dissolved to neutralize an acid component dissociated from aluminum sulfate or aluminum chloride, which will be described later. The resulting salt acts as a nucleus to promote the aggregation reaction. That is, it functions as an aggregation aid. The type of organic coagulant constituting the main component is not particularly limited, and any organic coagulant such as an anionic, cationic, or nonionic, which has been commercially available, may be used.

The organic coagulant functions to adsorb and crosslink fine aggregates formed by the action of other components to form coarse aggregates, thereby promoting the effect of separating the aggregates. Aluminum sulfate and aluminum chloride, which are other essential components in the purification treatment agent of the present invention, are dissolved and hydrolyzed immediately upon contact with the polluted wastewater,
In the case of aluminum sulfate, aluminum oxide and sulfuric acid
In the case of aluminum chloride, it dissociates into aluminum oxide and hydrochloric acid.

The aluminum oxide is converted into ionized colloidal polycondensed aluminum hydroxide,
By exerting the action of lowering the ζ potential on the S surface, the SS is agglomerated into fine particles. Further, in the alkaline region, it also has a function of mineralizing organic metal components and the like present in the polluted wastewater and sorbing and fixing dissolved pollutants such as metals.

Next, examples of the alkali metal carbonate include oxides such as sodium carbonate, calcium carbonate, magnesium carbonate, and dolomite. These alkali metal carbonates dissolve immediately upon contact with the polluted wastewater, and neutralize the acid component generated by the dissociation of aluminum sulfate and aluminum chloride. That is, it functions as a neutralizing agent.

In the purification treatment agent of the present invention, the main components are 30 to 50% by weight of a natural mineral and 45 to 50% of calcium sulfate.
It comprises 65% by weight and 1 to 5% by weight of an organic coagulant. If you have less than 30% by weight of natural minerals,
The above-mentioned effects of natural minerals are not sufficiently exhibited, and sorption / fixation / separation of dissolved pollutants, flocculation and separation of SS, and suppression of re-elution of separated sludge cannot be sufficiently realized. Also 5
When the content is more than 0% by weight, the above-mentioned effects of the natural mineral are saturated and not only the amount of use is wasted, but also the treated water starts to become cloudy and the relative proportion of other components is reduced to reduce the content of those components. The above effects are sacrificed. A preferred ratio is 35 to 45% by weight.

When the content of calcium sulfate is less than 30% by weight, the effect of promoting the aggregation of calcium sulfate as an agglomeration aid becomes insufficient, and the density of the agglomerates becomes low, so that the time required for the wastewater treatment becomes long, and the weight of 65% by weight. %, The above effect is saturated and not only wastes the amount of use, but also the treated water begins to become cloudy, and the relative proportion of other components is reduced, thereby reducing the effect of the component. Is done. Preferably, it is 50 to 60% by weight.

When the amount of the organic coagulant is less than 1% by weight, the above-mentioned action and effect of the organic coagulant is not sufficiently exhibited. Difficulty in post-processing. In the purification treatment agent of the present invention, aluminum sulfate, aluminum chloride, and alkali metal carbonate are further added to the above-mentioned main components.

In this case, the amounts of these essential components are determined in relation to the pH value of the polluted wastewater to be treated. For example, when the polluted wastewater is in the acidic region, a treatment is taken such that the blending amount of aluminum sulfate and aluminum chloride is reduced while the blending amount of the alkali metal carbonate is increased, so that the treated water becomes neutral. . Conversely, when the polluted wastewater is in the alkaline region, the content of aluminum sulfate and aluminum chloride is increased, and the content of alkali metal carbonate is reduced at the same time. In any case, the amounts of these three components are selected so that the treated water becomes neutral.

Since the above-mentioned specific action and effect of the natural mineral as the main component is effectively exerted in the pH range of 3 to 9, the compounding amount of the above three components depends on the amount of the obtained purification agent. The amount is set so that the pH value of the wastewater becomes 3 to 9 when the wastewater is charged into the polluted wastewater to be treated. Specifically, based on 100 parts by weight of the main component, 30 to 50 parts by weight of aluminum sulfate, 5 to 10 parts by weight of aluminum chloride, and 20 to 40 parts by weight of alkali metal carbonate are set. At this time, the pH value of the polluted wastewater falls within the range of 3 to 9, and the problem that the specific action and effect of the natural mineral is inhibited does not occur.

The above three components are adjusted to increase or decrease the amount of the treated water in order to make the treated water neutral within the above range of the amount of the main component. The purification treatment agent of the present invention is produced by mixing powders of the above-described components at a predetermined ratio. In use, it may be charged into the polluted wastewater and the whole may be stirred. The amount used at that time varies slightly depending on the properties of the polluted wastewater to be treated, but usually, the concentration for the polluted wastewater is 50 to 500 mg.
/ L.

It is preferable that the stirring is performed vigorously. Aggregates produced using the purification treatment agent of the present invention are hard and dense, and do not collapse or re-dissolve even with stirring,
Rather, the more the stirring is performed, the more effectively the above-mentioned effects of the respective components are exerted.

[0023]

【Example】

1. Preparation of Purification Agent Mixed powder consisting of montmorillonite, pyrophyllite, and kaolinite in a weight ratio of 8: 8: 7: 39.3
% By weight, anhydrous gypsum powder: 57.1% by weight, acrylamide coagulant and alginic acid coagulant in a weight ratio of 1.5:
Organic coagulant powder mixed at 0.5: 3.6% by weight was mixed to form the main component.

Next, with respect to 100 parts by weight of the main component,
39.3 parts by weight of aluminum sulfate powder, 7.1 parts by weight of aluminum chloride powder, 30.4 parts by weight of a mixed powder obtained by mixing sodium carbonate, calcium carbonate and dolomite in a weight ratio of 8: 4: 5. Were mixed to prepare a purification agent of the present invention. This purifying agent can be used for wastewater having a pH value of 4 to 9.

For comparison, the following flocculants were prepared.
In the main component of the above embodiment, alumina cement powder: 39.3% by weight, anhydrous gypsum powder: 57.1% by weight, acrylamide-based coagulant and alginic acid-based coagulant in a weight ratio of 1.5: 0.5. Organic coagulant powder mixed by 3.
The main component was constituted by mixing 6% by weight.

Next, with respect to 100 parts by weight of the main component,
39.3 parts by weight of aluminum sulfate powder, 7.1 parts by weight of aluminum chloride powder, 30.4 parts by weight of a mixed powder obtained by mixing sodium carbonate, calcium carbonate and dolomite in a weight ratio of 8: 4: 5. Was mixed to prepare a flocculant of Comparative Example. 2. Using these purification treatment agents, the following pollution wastewater treatment was performed.

1) Sewage treatment A Purification treatment agent of the present invention was added to the primary treated water obtained from the first sedimentation basin of the sewage treatment plant A and having the properties shown in Table 1.
And the whole was stirred. Table 1 shows the properties of the obtained supernatant. The results of the treatment with the coagulant of Comparative Example are also shown in Table 1.

[0028]

[Table 1]

Further, to the secondary treated water obtained from the final sedimentation basin and having the properties shown in Table 2, the treating agent of the present invention and the comparative flocculant were added in amounts shown in Table 2, respectively. About 1
Aeration for 0 hours was performed. Table 2 shows the obtained results.

[0030]

[Table 2]

2) Treatment of water tank sludge (tap water) Water tank sludge (tap water) having the properties shown in Table 3 was used as raw water, to which the treating agent of the present invention was added, and the whole was stirred. Table 3 shows the properties of the obtained supernatant. Further, the filtrate obtained after the water tank sludge was subjected to a dehydrator was used as raw water, and the treating agent of the present invention was added thereto and the whole was stirred. The properties of the obtained treated water are also shown in Table 3.

[0032]

[Table 3]

As is evident from Table 3, the treating agent of the present invention has an excellent ability to separate and remove not only SS but also dissolved metals. 3) Septic tank sludge treatment Septic tank sludge having the properties shown in Table 4 was selected as polluted wastewater, and this was treated with the treating agent of the present invention and the treating agent of the comparative example, respectively. Table 4 shows the properties of the obtained treated water in each case.

[0034]

[Table 4]

The same treatment was applied to the separated water from the sludge drawn from the septic tank. The properties of the obtained treated water are shown in Table 5.

[0036]

[Table 5]

Recently, septic tanks have become widespread, and with this, the amount of drawn sludge has increased, and measures for treating the sludge have become a problem. If the treating agent of the present invention is used in the sludge treatment, not only SS but also organic components are effectively separated and removed, and the supernatant can be purified to have a transparency of 30 or more. 4) Treatment of polluted effluent in the sewage treatment plant Sewage was stored in the digestion tank for 30 days, and the desorbed liquid at that time was selected as the polluted effluent, and this was treated with the treating agent of the present invention and the comparative example flocculant, respectively. . Table 6 shows the properties of the obtained treated water in each case.

[0038]

[Table 6]

The desorbed solution was subjected to aeration treatment, and the resulting treated water was treated with the treating agent of the present invention and the coagulant of Comparative Example, respectively. Table 7 shows the obtained results.

[0040]

[Table 7]

At present, in a human waste treatment plant, a liquid removed from a digestion tank is diluted 10 to 20 times with well water or river water and then treated in an aeration tank. However, in recent years, regulations such as pumping of well water have become strict, and in many cases, the above-mentioned treatment has been difficult. As is clear from the table, when the treating agent of the present invention is used, the desorbed solution can be subjected to aeration treatment without dilution, and from the properties of the obtained treated water, it can be used as dilution water for the desorbed solution. Can also be fully utilized. Further, the nitrogen component and the phosphorus component can be effectively separated and removed, which is useful.

5) Treatment of Swine Sewage Separated water after solid-liquid separation of swine manure was selected as polluted wastewater, and this was treated with the treating agent of the present invention and the coagulant of the comparative example, respectively. Table 8 shows the obtained results. The number of samples was three.

[0043]

[Table 8]

6) Wastewater treatment at a paper mill A effluent from the first sedimentation basin in a wastewater treatment facility at a paper mill was selected as polluted wastewater, and this was treated with the treating agent of the present invention and the flocculant of the comparative example, respectively. . Table 9 shows the obtained results.

[0045]

[Table 9]

The effluent was aerated, and the treated water obtained was treated with the treating agent of the present invention and a comparative flocculant. Table 10 shows the obtained results.

[0047]

[Table 10]

7) Wastewater treatment at leather factory As the polluted wastewater, the effluent from the first sedimentation basin in the wastewater treatment facility at the leather factory was selected and treated with the treatment agent of the present invention. Table 11 shows the obtained results.

[0049]

[Table 11]

As is clear from the table, the treating agent of the present invention can largely separate and remove dissolved Cr as well as SS and organic components. 8) Wastewater treatment at linen supply factory Wastewater from the linen supply factory was selected as polluted wastewater, and this was treated with the treatment agent of the present invention and the coagulant of the comparative example, respectively. Table 12 shows the obtained results.

[0051]

[Table 12]

As is clear from the table, the use of the treating agent of the present invention makes it possible to regenerate wastewater from a linen supply factory to a state where it can be reused. In addition, the regeneration can be performed without using activated carbon as in the related art, so that the processing cost can be reduced. 9) Treatment of wastewater from aircraft cleaning The wastewater from aircraft cleaning at the airport was selected as the polluted wastewater. In Japan, a method specified by the United States is used for the treatment of the washing wastewater.

This washing wastewater was treated with the treating agent of the present invention and the flocculant of Comparative Example. Table 13 shows the results. In addition,
The results from the treatment method specified by the United States are also shown.

[0054]

[Table 13]

10) Treatment of River Water, Pond in Pond, and Turbid Water during Tunnel Construction Water having the properties shown in Table 14 was selected as polluted waste water, and each was treated with the treating agent of the present invention. The results are shown in Table 14.

[0056]

[Table 14]

11) Wastewater treatment at a landfill disposal site Outflow water of an industrial waste (noncombustible waste) at a landfill disposal site was selected as polluted wastewater, and this was treated with the treatment agent of the present invention. The results are shown in Table 15.

[0058]

[Table 15]

12) Treatment of eluted wastewater from the dewatered cake The polluted wastewater (pH
After treating the values 4 to 9) with the treating agent of the present invention and the coagulant of Comparative Example, sludge was separated, and the separated sludge was subjected to dehydration treatment.
The amount added during the treatment was 300 mg / l. The obtained dehydrated cake was subjected to a dissolution test in accordance with the method specified in Notification 13 of the Environment Agency. Table 16 shows the results.

[0060]

[Table 16]

As is clear from the table, the use of the treating agent of the present invention suppressed the elution of metals from the dehydrated cake as compared with the case of the coagulant of Comparative Example. This is an effect brought about by the treatment agent of the present invention containing a natural mineral mainly composed of alumina and silicate. 13) Influence of the amount of each component in the main component Montmorillonite, pyrophyllite, and kaolinite were mixed at a weight ratio of 8: 8: 7 to prepare a mixed powder of a natural mineral.

The mixed powder, the anhydrous gypsum powder, and the organic coagulant powder obtained by mixing the acrylamide coagulant and the alginic acid coagulant in a weight ratio of 1.5: 0.5 are shown in Table 1.
The main component was prepared by mixing at the ratio (% by weight) shown in FIG. Table 17 shows aluminum sulfate powder, aluminum chloride powder, and carbonate powder obtained by mixing sodium carbonate, calcium carbonate, and dolomite at a weight ratio of 8: 4: 5 with respect to 100 parts by weight of the main component. They were mixed in proportions (parts by weight) to prepare four types of purification treatment agents.

[0063]

[Table 17]

Using these four kinds of treatment agents, muddy water for tunnel construction having the properties shown in Table 14 was treated. The results are shown in Table 18.

[0065]

[Table 18]

When the treating agents 2 and 3 were used, the formed floc was large, the sedimentation speed was high, and the interface with the separated sludge was clear. Table 1 also shows the transparency of the supernatant water.
As is clear from No. 8, it was 30 or more, and it was glossy. When the treating agent 1 is used, the amount of the natural mineral is small and the mineral component eluted therefrom is insufficient, so that the sorbing ability of Pb (solute pollutant) is inferior, and the excess anhydrous gypsum powder Are suspended and the transparency of the supernatant water is degraded. The formed flocs were also small, and the sedimentation speed was slow.

Further, when the treating agent 4 is used, since natural minerals are excessive, the minerals are suspended in treated water and the transparency thereof is deteriorated. Also, the formed flocs were weak and their density was low. From these facts, the proportions of natural mineral and anhydrous gypsum in the main components are 30 to 50% by weight, respectively.
It is understood that it should be set to 45 to 65% by weight.

[0068]

As is clear from the above description, the purification agent of the present invention simultaneously separates and removes not only SS in polluted wastewater but also dissolved pollutants such as metals dissolved therein. can do. In particular, the sludge after separation is stable, does not redissolve itself, suppresses the elution of dissolved pollutants, and has an effect not seen with conventional flocculants.

Further, the treated water treated with the purification treatment agent of the present invention becomes neutral, so that the conventional pH adjustment is not required, and the cost of operating the treatment line can be reduced.

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[Procedure amendment]

[Submission date] January 23, 1998

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Claims

[Correction method] Change

[Correction contents]

[Claims]

[Procedure amendment 2]

[Document name to be amended] Statement

[Correction target item name] 0006

[Correction method] Change

[Correction contents]

[0006]

In order to achieve the above-mentioned object, the present invention relates to a method for producing natural minerals mainly composed of alumina and silicate in an amount of 30 to 50% by weight and calcium sulfate 45.
Aluminum sulfate, 30 to 50 parts by weight per 100 parts by weight of the main component consisting of
Parts by weight, 5 to 10 parts by weight of aluminum chloride, and charcoal
Sodium acid, calcium carbonate, magnesium carbonate, de
A purification treatment agent for polluted effluent is provided, wherein 20 to 40 parts by weight of at least one selected from the group of lumite is blended.

[Procedure amendment 3]

[Document name to be amended] Statement

[Correction target item name] 0015

[Correction method] Change

[Correction contents]

Next, sodium carbonate, calcium carbonate,
Less selected from the group of magnesium carbonate and dolomite
Both of them dissolve immediately upon contact with the polluted wastewater and neutralize the acid component generated by the dissociation of aluminum sulfate and aluminum chloride. That is, it functions as a neutralizing agent.

[Procedure amendment 4]

[Document name to be amended] Statement

[Correction target item name] 0020

[Correction method] Change

[Correction contents]

Since the above-mentioned specific action and effect of the natural mineral as the main component is effectively exerted in the pH range of 3 to 9, the compounding amount of the above three components depends on the amount of the obtained purification agent. The amount is set so that the pH value of the wastewater becomes 3 to 9 when the wastewater is charged into the polluted wastewater to be treated. Specifically, based on 100 parts by weight of the main component, 30 to 50 parts by weight of aluminum sulfate, 5 to 10 parts by weight of aluminum chloride, and sodium carbonate, calcium carbonate , and magnesium carbonate
At least one selected from the group consisting of gnesium and dolomite
The seed is set to 20 to 40 parts by weight. At this time, the pH value of the polluted wastewater falls within the range of 3 to 9, and the problem that the specific action and effect of the natural mineral is inhibited does not occur.

Claims (3)

[Claims] 1. 30 to 50% by weight of a natural mineral mainly composed of alumina and silicate and 45 to 65% by weight of calcium sulfate
30 to 50 parts by weight of aluminum sulfate, 5 to 10 parts by weight of aluminum chloride, and 20 to 40 parts by weight of an alkali metal carbonate are mixed with 100 parts by weight of the main component consisting of 1% to 5% by weight of organic coagulant A purifying agent for polluted effluent, characterized in that: 2. The pollutant treatment agent according to claim 1, wherein the natural mineral is at least one selected from the group consisting of montmorillonite, pyrophyllite, and kaolinite. 3. The purification agent for polluted wastewater according to claim 1, wherein said alkali metal carbonate is at least one selected from the group consisting of sodium carbonate, calcium carbonate, magnesium carbonate, and dolomite.