JPH0655320B2 - Waste treatment agent and waste treatment method - Google Patents

Description

TECHNICAL FIELD The present invention relates to a waste treatment agent and a waste treatment method, and particularly to a waste containing a large amount of water such as sludge, sewage, and high-concentration drainage. Oxidative decomposition of pollutant pollutants in waste,
The present invention relates to a waste treatment agent used for adsorption and coagulation-precipitation, and a waste treatment method for removing water after oxidative decomposition, adsorption, coagulation-precipitation using the same.

<Prior art and its problems> Wastes containing a large amount of water, such as sludge, sewage, waste water, and high-concentration drainage, are pollutants such as high-concentration organic suspension substances and inorganic suspension substances. Suspended matter (hereinafter SS
(Also referred to as (SUSPENDED SOLID)), and may also contain various organic substances, oils, acids, alkalis, toxic substances, pollutants and pollutants such as heavy metals, It is considered to be a cause of water pollution and environmental pollution, and proper treatment has been strongly demanded.

However, even when separating pollutant pollutants and water from waste containing a large amount of water, the pollutant pollutants are aggregates of fine particles, and widely include colloidal and emulsified states, and water. Many were chemically bound, and there were limitations in the methods of mechanical and physical separation. Even if mechanical and physical separation is performed, pollutant pollutants are often sludge like so-called sludge, bulky, heavy, and fluid, so handling is difficult. Not only that, when these treated sludges are landfilled or dumped at sea, they are severely limited, and their treatment has been a problem.

Therefore, in order to coagulate and settle pollutant pollutants from excess sludge containing water and remove water, conventionally, sludge is generally introduced into a reaction tank and a large amount of organic polymer coagulates. The agent was added together with the inorganic coagulant to adsorb and condense the pollutant pollutants, and then dehydrated by a dehydrator. However, in such a method, not only a large amount of the organic polymer coagulant is necessary, but also the aggregation of the pollutant pollutants cannot be said to be sufficient, the volume of the aggregated precipitate does not become so small, and the aforementioned There were various problems like.

Further, at this time, since the aggregated precipitate contains various organic substances, some of them may give off a bad odor, and there is a problem that a secondary treatment is required.

For this reason, methods such as burning these coagulated sediments and performing biological treatment such as activated sludge method are also used, but the combustion method requires a large amount of energy, and the biological treatment method requires aeration treatment. Not only it was necessary to carefully control various conditions such as the method, but there was a problem that it took time and equipment to process a large amount of coagulated sediment.

In addition, since the water separated by the conventional method contains fine organic matter that could not be sufficiently aggregated, there is a bad odor, and SS and BOD of water (dissolved oxygen amount consumed by aerobic microorganisms) , COD (amount of oxidant (acidic potassium permanganate) consumed by oxidizable substances), etc. often exceed the discharge standard, and there is a problem that secondary treatment such as aeration treatment is necessary. there were.

<Object of the Invention> An object of the present invention is to solve the above-mentioned problems of the prior art, to provide an oxidizing agent, and a low molecular weight compound containing a carboxyl group and / or
^{Alternatively} , by adding an alkali salt thereof, in the presence of Fe ³⁺ , when treating a waste containing water, oxidative decomposition, adsorption, coagulation sedimentation of the pollutant from the waste is promoted, and It is an object of the present invention to provide a sewage treatment agent which can promote separation from water.

Another object of the present invention is to treat waste containing a large amount of water with an oxidizing agent, and then to treat F in the presence of a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof.
^Treating with e ³⁺ facilitates oxidative decomposition, adsorption and coagulation / precipitation of pollutant pollutants in waste, facilitates separation of pollutant pollutants and water, and then dehydrates to facilitate easy handling without odor. The object of the present invention is to provide a waste treatment method capable of obtaining not only a coagulated sediment containing a small amount of water but also an extremely small amount of water containing a pollutant pollutant having no bad odor.

Another object of the present invention is to further treat the sludge treated with the above-mentioned oxidizing agent, a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof, Fe ^{3+ with} an alkali,
Another object of the present invention is to provide a filth treatment method capable of further reducing the water content of the aggregated precipitate by promoting the adsorption and the aggregated precipitation and then dehydrating.

In addition, another object of the present invention is to further add an organic polymer coagulant to the above sludge treated with alkali,
Another object of the present invention is to provide a waste treatment method capable of measuring adsorption and coagulation-precipitation, reducing the water content of the coagulation-precipitation, and promoting solidification of the coagulation-precipitation.

<Structure of the Invention> The inventors of the present invention are keenly aware of a method for separating pollutant pollutants and water from wastewater or high-concentration wastewater, or separating water from sludge or the like, and converting the pollutant pollutants into a solid matter that is easy to handle. As a result of the research, the waste containing a large amount of water is first treated with an oxidizing agent, and then in the presence of a low molecular weight compound containing a carboxyl group and / or its alkali salt, F
It was found that water can be effectively separated and easily solidified by treating with e ³⁺ , or by further treating with alkali (neutralizing agent) and then with organic polymer flocculant. The present invention has been achieved.

That is, according to the first aspect of the present invention, a waste treatment agent used for separating and removing water from waste containing a large amount of water in the presence of Fe ³⁺ , comprising a oxidizing agent and a carboxyl group. It is possible to provide a waste treatment agent having a low molecular weight compound and / or an alkali salt thereof contained therein.

Further, according to the second aspect of the present invention, in removing water from a waste containing a large amount of water, the waste has an oxidizing agent and a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof. Treated with treatment agent, Fe
It is possible to provide a filth treatment method characterized by treating with a treatment agent that supplies ³⁺ to oxidatively decompose, adsorb, and coagulate the pollutant pollutants in the filth, and then dehydrate.

Further, according to the third aspect of the present invention, in removing water from a waste containing a large amount of water, the waste is an oxidizing agent, and a low-molecular compound containing a carboxyl group and / or
Alternatively, after treating with a treating agent having an alkali salt thereof and a treating agent supplying Fe ³⁺ , after treating with an alkali to oxidatively decompose, adsorb, coagulate and precipitate the pollutant contaminants in the waste. A method for treating waste is provided which is characterized by dehydration.

Further, according to the fourth aspect of the present invention, in removing water from a waste containing a large amount of water, the waste is an oxidant, and a low molecular weight compound containing a carboxyl group and / or
Alternatively, after treating with a treating agent having an alkali salt of a carboxyl group and a treating agent supplying Fe ³⁺ , it is then treated with alkali and further treated with an organic polymer coagulant. There is provided a filth treatment method comprising oxidatively decomposing, adsorbing, coagulating and precipitating a pollutant pollutant contained in the filth, followed by dehydration.

Hereinafter, the present invention will be described in more detail.

The filth to which the method of the present invention is applied may be any as long as it contains a high concentration of pollutant pollutants, for example, sewage, drainage, wastewater such as high concentration effluent and sludge, sake,
Examples include brewing residues such as shochu, soy sauce, human waste, human waste including animals, sludge, papermaking waste sludge, and wastewater treatment sludge. Here, pollutant pollutants are substances that are suspended, suspended, emulsified or dissolved in water,
Organic and inorganic suspended substances, various pollutants, organic substances such as starch, sugars, proteins, fats, solvents, surfactants and chelating agents, and oils such as mineral oils, fats, surfactants and emulsifiers , Acids and alkalis, inorganic and organic toxic substances, dyes and pigments, and malodorous components such as phenol, ammonia, hydrogen sulfide, lower fatty acids, amines and mercaptans.

A treatment agent having an oxidizing agent which is the waste treatment agent of the first aspect of the present invention and a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof (hereinafter referred to as "carboxyl group-containing compound") (hereinafter, referred to as " The "oxidation / dehydration treatment agent") only needs to contain an oxidant and a carboxyl group-containing compound, and the content thereof is the amount of Fe ³⁺ described later and
Since it is determined by BOD and COD in the waste, it cannot be generally stated, but 0.5% or more of the oxidant (oxygen equivalent) is mixed in the carboxyl group-containing compound (carboxyl group (-COOH) equivalent). preferable.

The reason for mixing the oxidant and the carboxyl group-containing compound here is that when separating and removing water from a waste containing a large amount of water, Fe ³⁺ added to promote coagulation and precipitation of pollutant pollutants in the waste is added. This is to make it easier to remove the water taken in by.

Also, it is effective when the filth contains a large amount of the oxidizable substance and SS. The combined action of Fe ³⁺ and the carboxyl group-containing compound will be described later.

The oxidizing agent used here is a commonly used oxidizing agent, and may be any as long as it does not cause environmental pollution, for example, an alkali salt of permanganate, or peroxides such as hydrogen peroxide, Alkali salts of oxygen acids such as hypochlorous acid, hypobromic acid, hypoiodic acid, chloric acid, bromic acid, iodic acid, perchloric acid and periodic acid, and halogens such as chlorine, bromine and iodine, Ozone and oxygen are preferred. More preferably, hydrogen peroxide, alkali salt of hypochlorous acid, ozone and the like are preferable.

The carboxyl group-containing compound used here may be any low molecular weight compound having a carboxyl group in the molecule or an alkali salt thereof, and may be any of low molecular weight carboxylic acids, oxy acids, amino acids and the like. . For example, carboxylic acids include formic acid, acetic acid, propionic acid, benzoic acid, and the like, oxyacids include lactic acid, malic acid, tartaric acid, citric acid, salicylic acid, and the like, and amino acids include glycine and alanine. And so on. More preferred are formic acid, acetic acid, propionic acid, benzoic acid, lactic acid and glycine.

When the waste treatment agent according to the first aspect of the present invention is used, Fe ³⁺
The treating agent that supplies Fe ³⁺ (hereinafter referred to as “iron-based inorganic coagulant”) used to make the
Any material can be used as long as it can supply Fe ³⁺ into the waste, for example, iron (III) sulfate Fe ₂ (SO ₄ ) ₃ · nH ₂ O
, Iron (III) chloride FeCl ₃・ 6H ₂ O, copparus chloride Fe ₂ (SO
₄ ) ₃・ FeCl ₃ and iron alum (NH ₄ ) ₂ Fe ₂ (SO ₄ ) ₄・ 24
Fe ³⁺ salts or iron sulfate such as _{H 2 O (II) FeSO 4} · 7H
₂ O and the like. A salt of Fe ³⁺ is more preferable.

Particularly preferred is iron (III) chloride.

Here, when the oxidation / dehydration treatment agent which is the waste treatment agent of the present invention is used in the presence of Fe ³⁺ , the iron-based inorganic flocculant and the oxidation / dehydration treatment agent used are iron-based inorganic flocculants (Fe ^{3 +}
(Converted) to 1 above-mentioned carboxyl group-containing compound (-C
It is preferable to add it so that the (OOH conversion) becomes 0.6 to 10.5.

Here, Fe ³⁺ supplied into the filth combines with the hydroxide ion in the filth to become iron (III) hydroxide Fe (OH) ₃ . Iron (III) hydroxide has a large adsorptive capacity and serves as a nucleus for coagulated precipitates. Further, iron (III) hydroxide is likely to be in a colloidal state and contains a large amount of water. Further, iron (III) hydroxide is usually simply represented as Fe (OH) ₃ , but Fe ³⁺ becomes, for example, [Fe (H ₂ O) ₆ ] (OH) ₃ coordinated with water as a ligand. And can be generally expressed as Fe ₂ O ₃ .nH ₂ O.

At this time, the carboxyl group-containing compound R-COOH becomes Fe (OH) ₃ (Fe ₂ O
₃ · nH ₂ O) has the effect of releasing water. Although this effect is not completely understood, it can be considered as follows.

For example, as a carboxyl group-containing compound, acetic acid CH ₃ COOH
For example, Fe ³⁺ and acetate ions react with each other to form various compounds. For example, when the pH is low, 3.2 to 3.6, especially when the temperature is raised, Fe (CH ₃ COO) (O
It is considered that H) ₂ is released to release the water taken up by Fe ₂ O ₃ · nH ₂ O (Fe (OH) ₃ ) into the molecule. However, with Fe (CH ₃ COO) (OH) ₂ only, Fe ₂ O ₃ nH ₂ O (Fe (OH) 2
_The adsorption capacity is smaller than that of ₃ ).

On the other hand, as the pH is raised, Fe ₂ O ₃ · nH ₂ O (Fe (OH) ₃ ) begins to form, so Fe (CH ₃ COO) (OH) ₂ and Fe ₂ O ₃ · nH ₂ O A complex of However, when Fe ₂ O ₃ · nH ₂ O increases, the adsorption capacity increases but the water content also increases.

In addition, as a compound of Fe ³⁺ and CH ₃ COO ⁻ , [Fe
₃ (CH ₃ COO) ₆ ] (CH ₃ COO) ₃ , [Fe ₃ (CH ₃ COO) ₆ (OH) ₂ ] (CH ₃ COO) ・ H ₂ O, [Fe ₃ (CH ₃ COO) ₆ (OH ) ₂ ] (CH ₃ COO) · 4H ₂ O, [Fe ₃ (CH ₃ COO) ₆ (OH)] (CH ₃ COO) ₂ and composites thereof.

As described above, carboxyl group-containing compounds such as acetic acid (CH ₃ COOH) are Fe ₂ O ₃ · nH ₂ produced by the iron-based inorganic coagulant.
The effect of releasing water from O (Fe (OH) ₃ ) is great, but if the carboxyl group-containing compound (-COOH conversion) is less than 0.6 with respect to 1 iron-based inorganic coagulant (Fe ³⁺ conversion), water release Is less, and the effect of reducing the volume of the aggregated precipitate is small. Further, if the carboxyl group-containing compound exceeds 10.5, the adsorbing ability becomes small, so that the effect of reducing BOD and COD becomes small, and there is a possibility that secondary pollution may occur.

The waste treatment agent of the present invention has been described above, but the waste treatment method of the present invention will be described below.

1st of the waste treatment method of the 2nd, 3rd, and 4th aspect of this invention
In the step, the oxidizing / dehydrating treatment agent according to the first aspect of the present invention can be used, and in the second step, only the iron-based inorganic coagulant described above can be used. Of course, in the first step, instead of the oxidizing / dehydrating treatment agent of the first aspect of the present invention, the oxidizing agent and the carboxyl group-containing compound may be separately supplied in the above-mentioned proportions. Either of the oxidizing agent and the carboxyl group-containing compound may be supplied first, or they may be supplied simultaneously.

The alkali (neutralizing agent) used in the third step of the waste treatment method of the third and fourth aspects of the present invention may be any as long as it can control the pH of the treated sludge up to the second step. Examples thereof include sodium hydroxide, potassium hydroxide, calcium hydroxide, barium hydroxide, sodium carbonate and sodium hydrogen carbonate.

The organic polymer flocculant used in the fourth step of the waste treatment method of the fourth aspect of the present invention may be a commonly used one, and may be a cation type, an anion type or a nonionic type. sodium polyacrylate is a cationic organic polymer flocculant _{[-CH (COONa) -CH 2 -} ]
_n , a partially hydrolyzed salt of polyacrylamide [-(-CH ₂ -CH (CONH ₂ ) ₃ -CH ₂ -CH (COONa)-] _n, etc. are typical examples, and as anionic organic polymer flocculants, ,
Polyethyleneimine [-CH ₂ -CH ₂ NH-] _n , quaternary ammonium salts Non-ionic organic polymer flocculants include polyacrylamide [-CH (CONH ₂ ) -CH _2- ] _n , polyoxyethylene [-CH ₂ -CH ₂ O-] _n, etc. Typical examples include: FIG. 1 shows a schematic diagram of an embodiment of the second aspect of the present invention.

In FIG. 1, a waste treatment tank 10 is used to carry out the waste treatment method of this embodiment. First, storage tank 1
The waste 14 in 2 is sent to the first tank 18 of the waste disposal tank 10 by the pump 16. In the first step of this embodiment, the first tank 1
Oxidation / dehydration treatment agent is supplied to 8 by the oxidation treatment agent supply means 20.

Here, the reason for adding the oxidizing / dehydrating treatment agent to the first tank 18 is that the oxidizing agent in the treating agent oxidizes and decomposes the waste and
Iron hydroxide (I
I) to oxidize Fe (OH) ₂ into iron (III) hydroxide Fe (OH) ₃ , and the carboxyl group-containing compound in the treating agent is produced by the iron-based inorganic flocculant as described above. This is to facilitate the release of water from iron (III) hydroxide containing a large amount of water. If an iron-based inorganic coagulant is used to measure coagulation-precipitation, and if the coagulation-precipitation is separated from the filtrate (water) and an oxidizing agent is not supplied, iron hydroxide (II) will appear on the acidic or neutral side.
Does not coagulate and settle, and remains in the filtrate. When the filtrate comes into contact with air, iron (II) hydroxide becomes iron (III) hydroxide and precipitates as a red suspension. is there. Thus, unless an oxidizing agent is used, sufficient aggregation and precipitation cannot be performed on the alkaline side, and on the acidic or neutral side, the filtrate after dehydration separation requires further aeration treatment. Further, when using an iron-based inorganic coagulant as described above, when a carboxyl group-containing compound is supplied, iron hydroxide (III) produced (Fe ₂ O ₃ · nH ₂ O, Fe (OH) ₃ ) Can significantly remove water. The amount of the oxidizing / dehydrating treatment agent is not limited, and may be appropriately determined depending on the amount or concentration of the oxidizable substance in the waste and the amount of the iron-based inorganic coagulant supplied in the second step. For example, for an iron-based inorganic coagulant (converted to Fe ³⁺ ), a carboxyl group-containing compound (converted to —COOH) 0.6
It is preferably set to ˜10.5.

It is preferable to stir the waste in the first tank 18 by the stirrer 22 so that the waste 14 sufficiently reacts with the oxidizing / dehydrating treatment agent and is oxidatively decomposed. The stirring speed is preferably 200 to 400 rpm. The reason for this is that if the speed is less than 200 rpm, the stirring efficiency is poor, and if it exceeds 400 rpm, it is disadvantageous in terms of cost.

Thus, the waste that has sufficiently reacted with the oxidizing / dehydrating treatment agent is sent from the first tank 18 to the second tank 24.

In the second step of the present invention, the iron-based inorganic coagulant is supplied to the second tank 24 by the coagulant supply means 26. Here, the reason for reacting the waste with the iron-based inorganic coagulant in the second tank 24 is that the pollutant contaminant in the waste is a porous cotton-like precipitate Fe (OH) ₃ or Fe ₂ O generated from the iron-based inorganic coagulant. _This is because it is easy to aggregate and precipitate with ₃ · nH ₂ O as a nucleus. Also, the combination of the oxidizing agent and iron promotes the decomposition of the excess oxidizing agent because iron acts as a catalyst. In addition, the carboxyl group-containing compound is Fe ₂ O generated by the iron-based inorganic coagulant.
_Since a large amount of water can be released from ₃ · nH ₂ O, the volume of the aggregated precipitate can be greatly reduced.

The amount of the iron-based inorganic coagulant added is not particularly limited and may be appropriately determined according to the amount of suspended solids (SS) in the waste. For example, in the case of wastewater containing more water than SS1%, it is preferable to set Fe ³⁺ to 10 ppm to 10,000 ppm, and in the case of SS1 to 10% sludge, Fe ³⁺ to 1 ppm.
It is preferably set to 00 ppmH to 30,000 ppm. When a large amount of Fe ³⁺ or Fe ²⁺ is previously contained in the pickling waste liquid such as steel, it can be adjusted depending on the concentration.

The waste in the second tank 24 is preferably stirred by the stirrer 22 so that the waste and the iron-based inorganic coagulant are sufficiently mixed. At this time, the stirring speed is preferably 200 rpm to 400 rpm. The reason for this is that if the speed is less than 200 rpm, the stirring efficiency is poor, and 4
This is because if it exceeds 00 rpm, it is disadvantageous in terms of cost.

In this way, the polluted pollutants in the waste are sufficiently oxidatively decomposed, adsorbed, and coagulated and precipitated. At this time, the pollutant pollutants in the coagulated sediments have good water separation due to the action of the carboxyl group-containing compound, so-called drainage. After that, these wastes are sent to the dehydrator 40 and easily separated into a coagulated sediment 42 and a water content 44 as a filtrate. The dehydration method used here may be any dehydration method as long as the aggregated precipitate 42 and the water 44 can be suitably separated, and, for example, a pressing method, a suction method, a press suction method, a centrifugal separation method and the like are representatively mentioned. The dehydrator may be any one that uses felt or wire as the filter medium.

The water content of the coagulated precipitate 42 thus obtained depends on the dehydrator used, but in the case of the pressing method, it is typically 50 to 50%.
The water content is 65% or less. For this reason, the aggregated precipitate 42 has good water separation due to the action of the carboxyl group-containing compound, so that it can be easily solidified, has a small volume and small weight, and is treated with an oxidizing agent first, It has no bad odor and is extremely easy to handle. Further, these coagulated sediments may be used for landfill and dumped at sea, but since they often contain a large amount of organic substances, they can be reused as fertilizers. Further, the separated and removed filtrate has a sufficient bleaching property without giving off a bad odor, and SS, BOD and COD are remarkably lowered as compared with the conventional ones. Depending on the type of waste before treatment, BO
Although D, COD, etc. are abnormally high and some require secondary treatment, SS, BOD, COD of the above-mentioned filtrate generally satisfy the discharge standard, except for these contaminants. It can be discharged as it is without any secondary treatment.

As described above, by adding a carboxyl group-containing compound, by treating with an oxidizing agent, an iron-based inorganic coagulant, oxidative decomposition, adsorption, coagulation sedimentation of the pollutant pollutants in the waste sufficiently, and as a cohesive sediment with good water separation Although it can decompose and remove water,
Further, in order to promote oxidative decomposition, adsorption, coagulation-precipitation, and enhance the effect of removing water, the pH may be adjusted with an alkali in the third step as in the third aspect of the present invention,
As in the fourth aspect of the present invention, by further mixing with the organic polymer coagulant in the fourth step, water can be further separated and removed from the waste.

As in the fourth aspect of the present invention, FIG. 2 shows a schematic diagram of an embodiment of the waste treatment method for performing the third step and the fourth step in addition to the first step and the second step.

In FIG. 2, the same elements as those shown in FIG. 1 are designated by the same reference numerals, and detailed description thereof will be omitted.

First, the waste 14 in the storage tank 12 is sent to the first tank 18 of the waste processing tank 10 by the pump 16. In the first step of the present invention, the oxidation / dehydration treatment agent is supplied to the first tank 18 by the oxidation treatment agent supply means 20 and sufficiently stirred by the stirrer 22 so as to react with the waste 14.

Next, in the second step, the waste that has sufficiently reacted with the oxidizing / dehydrating treatment agent is sent to the second tank 24 and mixed with the iron-based inorganic coagulant supplied to the second tank 24 by the coagulant supply means 26. .
The waste in the second tank 24 and the iron-based inorganic coagulant are sufficiently stirred by the stirrer 22. Here, the waste in the second tank 24 is treated with an oxidizing agent, a carboxyl group-containing compound, and an iron-based inorganic coagulant by any method, and the pollutant pollutants in the waste are sufficient. It also undergoes oxidative decomposition, adsorption, aggregation and precipitation, and the separation of water is also promoted.

Further, it is sent to the third tank in order to promote the aggregation and precipitation of polluted pollutants in the waste. In the third step, the alkali is the third
It is supplied from the alkali supply means 32 in order to adjust the pH of the waste in the tank 30. The waste in the third tank 30 may be on the acidic side or the alkaline side, but it is generally preferable that the pH is within the discharge standard. More preferably, the pH is 5.8.
It is good to adjust to ~ 8.5.

Whether the pH is adjusted to the acidic side or the alkaline side can be determined by the amount and concentration of the dissolved ionic pollutant.

Here, when the waste contains a lot of negatively charged colloids and the like, when the pH is on the acidic side, aggregation and precipitation by Fe (OH) ₃ are promoted, and when the waste contains a lot of positively charged colloids, The reason is that when the pH is on the alkaline side, aggregation and precipitation due to Fe (OH) ₃ is promoted.

The amount of alkali supplied may be appropriately determined according to the required pH of the waste in the third tank 30. Also in the third tank 30, the stirrer 22 should be sufficiently stirred by the stirrer 22 to promote the aggregation and precipitation of the pollutant pollutants in the waste. The stirring speed may be appropriately determined depending on the size of the third tank 30, but is usually preferably 50 to 200 rpm. The reason for this is 50
If it is less than rpm, the stirring efficiency is lowered, which hinders the formation of Fe (OH) ₃ , and if it exceeds 200 rpm, it is disadvantageous in terms of cost.
This is because the flocs of H) ₃ are crushed and the Fe (OH) ₃ adsorption capacity is reduced.

In the third aspect of the present invention, after this, the polluted matter in which the pollutant is coagulated and precipitated is treated by the dehydrator 40, and since the water separation is good due to the action of the carboxyl group-containing compound, the coagulated precipitate 42 and the filtrate are combined. Easily separated into some water 44,
When the water content of the aggregated precipitate is further reduced to reduce the volume, the pH-adjusted waste is sent to the fourth tank 34 before the dehydration, and the treatment of the fourth step is performed.

In the fourth step, the organic polymer coagulant is supplied to the waste in the fourth tank 34 by the organic polymer coagulant supply means 36.

The supply amount of the organic polymer coagulant is preferably 100 ppm or less of the waste. More preferably, it is 10 to 30 ppm. The reason for this is that if the concentration exceeds 100 ppm, the organic polymer coagulant itself, which does not function for coagulating sedimentation of pollutant pollutants in the filth, retains water,
This is because the aggregated precipitate has a good water retention property, so that the dehydration efficiency at the time of dehydration deteriorates.

The lower limit does not need to be particularly limited, but it is preferable that the particles of the aggregated precipitate are not too small.

It is preferable to stir with the stirrer 22 in order to sufficiently mix the waste in the fourth tank 34 and the organic polymer coagulant. The stirring speed may be appropriately determined according to the size of the fourth tank 34, but is usually preferably 50 to 200 rpm. The reason for this is 50
If it is less than rpm, the stirring efficiency is lowered, which hinders the formation of Fe (OH) ₃ , and if it exceeds 200 rpm, it is disadvantageous in terms of cost.
This is because the flocs of H) ₃ are crushed and the Fe (OH) ₃ adsorption capacity is reduced.

In this way, the filth, which has sufficiently aggregated and settled the pollutant pollutant, has good water separation by the action of the carboxyl group-containing compound, so that the effluent is easily dehydrated by the dehydrator 40 and the coagulated sediment 42 and the water content of the filtrate. And 44.

The water content of the aggregated precipitate 42 thus obtained is 5
It can be suppressed to 0 to 65% or less. Therefore, the aggregated precipitate 42 is formed by the action of the carboxyl group-containing compound.
Since water is being removed, solidification can be further facilitated, volume and weight can be further reduced, and handling is extremely easy. Further, in the present invention, since it is first treated with the oxidizer of the waste, it does not have a bad odor and is easy to handle. Further, these aggregated precipitates 42 may be used for landfill and dumped at sea, but can be reused as fertilizer as described above. Further, as described above, the water content 44 as the filtrate is also sufficiently decolorized without a bad odor, and SS, BOD, and COD are remarkably lowered as compared with the conventional one. Depending on the type of filth before treatment, BOD, COD, etc. are abnormally high, and some require secondary treatment. However, except for these filths, SS, BOD, COD of the above-mentioned filtrate are also generally high. Since it fully satisfies the discharge standard, it can be discharged as it is without any secondary treatment.

The waste treatment method of the present invention is basically configured as described above, but is not limited to this, and it goes without saying that various improvements can be made without departing from the scope of the present invention. .

<Examples> The present invention will be specifically described below based on Examples and Comparative Examples.

(Example 1) 3 pig swine wastewater (containing 40,000 ppm SS) was used as waste.
Using m ³ / h, oxidizing / dehydrating treatment agent in the first tank with a capacity of 250
(NaClO: CH ₃ OOH = 1: 5) per 1 m ³ of filth NaclO: 100
0ppm, CH ₃ COOH: supplied so as to 5000 ppm,
After stirring at a stirring rate of 295 rPm to allow sufficient reaction,
It was delivered to the second tank. 1 m ³ of filth in the second tank with a volume of 250
Feeding 5000ppm FeCl ₃ per unit, stirring speed 29
By stirring at 5 rpm, the pollutant pollutants in the waste were sufficiently aggregated and precipitated. Then, the product was dehydrated with a press type dehydrator to obtain 300 kg / hr of coagulated precipitate and 2700 kg / hr of filtrate (water).

(Example 2) 3 pig swine wastewater (containing 40,000 ppm of SS) was used as waste.
m ³ / h using a first tank oxidation and dehydration agent volume _{250 (NaClO: CH 3 COOH =} 1: 5) filth 1 m ³ per NaClO: 100
0ppm, CH ₃ COOH: supplied so as to 5000 ppm,
After stirring at a stirring speed of 295 rpm for sufficient reaction,
It was supplied to the second tank. 1 m ³ of filth in the second tank with a volume of 250
Feeding 5000ppm FeCl ₃ per unit, stirring speed 29
After stirring at 5 rpm to sufficiently agglomerate and settle the pollutant contaminants in the waste, it was fed to the third tank. Volume 250 third
2000 ppm of 25% NaOH per 1 m ³ of filth was fed to the tank and stirred at a stirring speed of 150 rpm to adjust the pH of the filth in the third tank to 6.8 to further promote aggregation and precipitation.

After that, it was dehydrated with a press type dehydrator, and 270 kg of coagulated sediment
/ hr and filtrate 2730 kg / hr were obtained.

(Example 3) 3 pig swine wastewater (containing 40,000 ppm of SS) was used as waste.
Using m ³ / h, oxidizing / dehydrating treatment agent in the first tank with a capacity of 250
(NaClO: CH ₃ OOH = 1: 5) per 1 m ³ of waste, NaclO: 10
00 ppm and CH ₃ COOH: 5000 ppm were supplied, and the mixture was stirred at a stirring rate of 295 rpm for sufficient reaction and then fed to the second tank. Waste 1 in the second tank with a volume of 250
FeCl ₃ of 5000 ppm per m ³ was supplied and stirred at a stirring speed of 295 rpm to sufficiently agglomerate and contaminate the polluted pollutants in the sewage, and then the slag was fed to the third tank. Volume 250
2000 ppm of 25% NaO per 1 m ³ of waste in the third tank of
After supplying H and stirring at a stirring speed of 150 rpm, the pH of the waste in the third tank was adjusted to 6.8 to further promote coagulation and sedimentation, and then it was sent to the fourth tank. Cliflock anion (manufactured by Kurita Water Industries Ltd.) of 30 ppm per 1 m ³ of filth was fed to the fourth tank having a volume of 250 and stirred at a stirring speed of 150 rpm to further promote coagulation and precipitation.

After this, dehydration with a press-type dehydrator, 240 kg of coagulated sediment
/ hr and filtrate 2760 kg / hr were obtained.

(Comparative Example 1) 3 pig swine wastewater (containing 40,000 ppm SS) was used as waste.
m ³ / h, 1 per 1 m ³ of waste in the first tank with a volume of 250
Supply 000ppm NaClO, stirring speed 295rpm
After being stirred at, the reaction was sufficiently performed, and then the mixture was fed to the second tank.
FeCl ₃ of 5000 ppm per 1 m ³ of filth was supplied to the second tank having a volume of 250 and stirred at a stirring speed of 295 rpm,
The pollutant pollutants in the waste were sufficiently aggregated and precipitated.

After this, dehydration with a press type dehydrator, 400 kg of coagulated sediment
/ hr and a filtrate (water content) of 2600 kg / hr were obtained.

(Comparative Example 2) 3 pig swine wastewater (containing 40,000 ppm of SS) was used as waste.
m ³ / h, 1 per 1 m ³ of waste in the first tank with a volume of 250
000 ppm of NaClO was supplied, and the mixture was stirred at a stirring rate of 295 rpm for sufficient reaction and then fed to the second tank. 5000ppm of F per 1m ³ of filth in the second tank with a volume of 250
After supplying eCl ₃ and stirring at a stirring speed of 295 rpm to sufficiently aggregate and precipitate the polluted pollutants in the waste, the mixture was sent to the third tank. 2 per 1 m ³ of waste in the third tank with a volume of 250
Supply 000ppm of 25% NaOH, stirring speed 150
The pH of the waste in the third tank was adjusted to 6.8 by stirring at rpm to further promote coagulation and precipitation.

After this, dehydration with a press type dehydrator, 400 kg of coagulated sediment
/ hr and filtrate 2600 kg / hr were obtained.

(Comparative Example 3) 3 pig swine wastewater (containing 40,000 ppm of SS) was used as waste.
m ³ / h, 1 per 1 m ³ of waste in the first tank with a volume of 250
000ppm of NaClO is supplied, stirring speed is 295rpm
After being stirred at, the reaction was sufficiently performed, and then the mixture was fed to the second tank.
To the second tank with a volume of 250, 5000 ppm of FeCl ₃ was added per 1 m ³ of waste, and the mixture was stirred at a stirring speed of 295 rpm,
After the pollutant pollutants in the waste are sufficiently aggregated and settled, the third
Delivered to the tank. 2000 ppm of 25% NaOH was added to 1 m ³ of filth in a third tank with a volume of 250, and stirring speed was 15
After stirring at 0 rpm to adjust the pH of the waste in the third tank to 6.8 and further promoting coagulation and precipitation, it was fed to the fourth tank. 30 ppm of Cliflock anion (manufactured by Kurita Water Industries Ltd.) per 1 m ³ of filth was sent to the 4th tank with a volume of 250,
Stirring was carried out at a stirring speed of 150 rpm to further promote coagulation and precipitation.

After this, dehydration with a press type dehydrator, 350 kg of coagulated sediment
/ hr and filtrate 2650 kg / hr were obtained.

(Comparative Example 4) 3 pig swine wastewater (containing 40,000 ppm of SS) was used as waste.
m ³ / h, 300 ppm of Cliflock anion per 1 m ^{3 of} filth was simultaneously supplied to a reaction tank with a volume of 100, and 2
By stirring at 95 rpm, the pollutant contaminants in the waste were coagulated and precipitated.

After that, it was dehydrated with a press-type dehydrator to give 480 kg of coagulated sediment.
/ hr and 2520 kg / hr of filtrate were obtained.

As described above, the odor and the content of the filtrate (water) of the aggregated precipitates obtained in Examples 1, 2, 3 and Comparative Examples 1, 2, 3, 4 were measured. Further, the odor of the filtrate (water), SS and COD were measured.

The results are shown in Table 1.

As is clear from Table 1, Examples 1, 2, 3 of the present invention
Each of the agglomerated precipitates has no bad odor as compared with Comparative Examples 1 to 4, and the water content is small due to the action of the carboxyl group-containing compound, so that the water content is small and it easily solidifies and is easy to handle. It is extremely easy, has a low water content, and therefore has a small volume and weight. In addition, Examples 1, 2, 3
Compared to Comparative Examples 1 to 4, the water content of each had no bad odor,
SS and COD are also low.

<Effects of the Invention> As described in detail above, according to the present invention, the pollutant contaminants in the waste containing a large amount of water are sufficiently oxidatively decomposed and adsorbed,
Since it can be coagulated and precipitated, and the water content can be improved by the action of the low molecular weight compound containing a carboxyl group and / or its alkali salt, the water content of the coagulated precipitate obtained by dehydrating the waste can be increased. Can be made smaller. Therefore, the volume and weight of the coagulated sediment obtained from a certain amount of waste can be reduced, and since the oxidizing agent treatment is performed first, the pollutant pollutants are sufficiently oxidatively decomposed and adsorbed, and there is no foul odor and the solid is easily solidified. It can be made into a material and is extremely easy to handle. Furthermore, this coagulated sediment can be reused as fertilizer as well as for landfill and dumping at sea.

Further, according to the present invention, since the pollutant pollutants in the waste are sufficiently aggregated and settled, the filtrate (water) separated by the dehydration treatment does not have a bad odor and is sufficiently decolorized, SS,
Since the BOD and COD are also low and satisfy the discharge standard, it can be discharged as it is without any secondary treatment except in special cases.

Further, according to the present invention, the amount of the expensive polymer flocculant used can be significantly reduced, so that the waste treatment can be performed efficiently and inexpensively.

Further, according to the present invention, since it can be applied to sludge and the like in which it is extremely difficult to separate and remove water, it can also be applied to residues after the primary treatment.

[Brief description of drawings]

FIG. 1 is a schematic view of an embodiment of the waste treatment method of the present invention. FIG. 2 is a schematic view of another embodiment of the waste treatment method of the present invention. Explanation of reference numerals 10 ... Waste treatment tank, 12 ... Storage tank, 14 ... Waste, 16 ... Pump, 18 ... First tank, 20 ... Oxidizing agent supply means, 22 ... Stirrer, 24 ... 2nd tank, 26 ... Flocculating agent supplying means, 30 ... Third tank, 32 ... Alkali supplying means, 34 ... Fourth tank, 36 ... Organic polymer flocculant supplying means, 40 ... Dehydrator 42 ... Aggregated sediment, 44 ... Moisture

Continuation of the front page (56) Reference JP 55-1851 (JP, A) JP 57-32799 (JP, A) JP 51-98145 (JP, A) JP 53-110964 (JP , A) Japanese Patent Publication Sho 51-46756 (JP, B2)

Claims (4)

[Claims] 1. A waste treatment agent used for separating and removing water from waste containing a large amount of water in the presence of Fe ³⁺ , which is a low molecular compound containing an oxidizing agent and a carboxyl group and / or A waste treatment agent comprising the alkali salt. 2. When removing water from a waste containing a large amount of water, the waste is treated with a treating agent having an oxidizing agent and a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof, and Fe is treated. A filth treatment method comprising treating with a treatment agent that supplies ³⁺ to oxidatively decompose, adsorb, and coagulate the pollutant pollutants in the filth, and then dehydrate. 3. When removing water from a waste containing a large amount of water, the waste is treated with an oxidizing agent, a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof, and Fe ^3+. A treatment method for treating a filth, which is characterized in that after treatment with a treating agent for supplying the above, it is treated with an alkali to oxidatively decompose, adsorb, coagulate and precipitate the pollutant pollutants in the filth, and then dehydrated. 4. When removing water from a waste containing a large amount of water, the waste is treated with an oxidizing agent, a low molecular weight compound containing a carboxyl group and / or an alkali salt thereof, and Fe ^3+. After treatment with a treating agent for supplying, then treatment with an alkali and further treatment with an organic polymer flocculant were carried out to oxidatively decompose, adsorb, and flocculate the pollutant contaminants contained in the waste. A filth disposal method characterized by dehydration afterwards.