JP2021171711A - Sludge solidifying agent with deodorant effect - Google Patents

Abstract

To provide a sludge solidifying agent added to organic sludge, that can obtain strength in a short time at a low cost, does not pollute soil or groundwater, and can suppress generation of malodor.SOLUTION: The sludge solidifying agent of the present invention is configured as a powdery sludge solidifying agent to be added and kneaded when landfilling and treating organic sludge made into a dehydrated cake, and is produced from following materials. That is, the sludge solidifying agent is produced from Portland cement, hemihydrate gypsum, and a powdery deodorizer containing a betaine compound as a main component, and a weight ratio of Portland cement to hemihydrate gypsum is 8:2 to 6:4. Then, if necessary, sodium silicate No.3 or magnesium oxide may be added. Further, an admixture consisting of lignin sulfonic acid or a derivative thereof may be added.SELECTED DRAWING: Figure 1

Description

According to the present invention, sludge solidification is added to and kneaded with organic sludge when landfilling organic sludge containing a large amount of organic matter discharged in a sewage treatment facility, a sewage treatment plant, a water purification plant, etc. It is about agents.

So-called organic sludge containing a large amount of organic matter discharged from human waste treatment facilities, sewage treatment plants, water purification plants, etc. is dehydrated into dehydrated cakes and landfilled. By the way, even if organic sludge is made into a dehydrated cake, it contains a large amount of water with a moisture content of about 80%, so it may liquefy due to vibration during transportation, or if rainwater or the like is mixed in at the burial treatment plant, it will contain moisture. The rate becomes high and it becomes easy to fluidize. Then, after landfill, sludge outflow pollution will occur. In order to prevent such a state, in the burial treatment plant, an inorganic solidifying agent such as cement is added to the organic sludge and solidified to a predetermined hardness by a hydration reaction or a pozzolan reaction, or organic solidified. It is practiced to add an agent to cause polymer cross-linking and agglomerate organic sludge.

Organic sludge also has the problem of foul odors. The causative substance of malodor, that is, the malodorous substance, has hydrophilicity and is contained in a large amount in water in organic sludge. Such malodorous substances volatilize and diffuse, deteriorating the surrounding environment of the burial treatment plant. As a method of suppressing malodor, a dry solidification method in which organic sludge is dried to eliminate the water in which the causative substance is dissolved, a chemical reaction method in which a predetermined substance is added and chemically reacted with the malodorous substance to change it into an odorless substance, Masking method that makes it relatively difficult to feel malodorous substances by adding other substances that have strong odors that are not unpleasant, and pairing method that adds substances with specific odors that do not become unpleasant odors when combined with malodorous substances , A direct detoxification method for deodorizing malodorous substances volatilized by substances with strong oxidizing power such as hydroxyl radicals and ozone is well known.

JP-A-2002-363560 Japanese Unexamined Patent Publication No. 2005-11302 Patent No. 6363281 JP-A-59-145100 Japanese Unexamined Patent Publication No. 61-86992 Japanese Unexamined Patent Publication No. 2005-131595

There are various treatment agents for treating sludge, and various proposals have been made in the patent literature. Patent Document 1 describes a soil conditioner for treating hedro-like sludge and the like. This soil conditioner consists of incinerator ash, Portland cement, sulfuric acid band, anhydrous gypsum, etc., and when it is added to soft soil with high water content or heddle-like sludge and kneaded, it becomes aggregated soil suitable for plant growth. Can be improved. Patent Document 2 also describes a soil stabilizing and solidifying agent that is added to soft soil or heddle-like sludge to improve the soil with an appropriate degree of water retention. This soil stabilizing and solidifying agent consists of paper sludge ash, fly ash ash, zeolite component, Portland cement, anhydrous gypsum and the like. It should be noted that Patent Documents 1 and 2 describe that anhydrous gypsum absorbs water and solidifies by a hydration reaction, but since anhydrous gypsum hardly undergoes a hydration reaction, it is also called dead gypsum and hardly undergoes a hydration reaction. Then, the interpretation of the "hydration reaction" described in these documents is considered to mean a hydration reaction that progresses slightly over an extremely long period of time.

Patent Document 3 describes a solidifying agent that is added to sludge generated in civil engineering work and the like to solidify it into granules. This solidifying agent contains a polymer flocculant in addition to zeolite, magnesium compound and the like. Patent Document 4 describes a solidifying agent for solidifying sewage sludge, that is, the organic sludge targeted by the present invention. This solidifying agent consists of Portland cement, aluminum sulfate, that is, a sulfate band, gypsum and the like. When this solidifying agent is added to the organic sludge and kneaded, the organic sludge can be solidified. In this document, it is described that gypsum can be used as any of anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum. Since gypsum other than hemihydrate gypsum does not undergo a hydration reaction at all or hardly undergoes a hydration reaction, it is considered that the action required for gypsum is not a hydration reaction. This document states that gypsum is added so that the amount of ettrin guide produced by the hydration reaction of Portland cement is not insufficient. Patent Document 5 describes a treatment method for treating sludge water discharged in civil engineering work. In this treatment method, a sulfate band is added to sludge water to aggregate and settle, and Portland cement, gypsum, etc. are added and mixed with the settling. Although the action of gypsum in this treatment method is unknown, it is described in this document that gypsum can be used in any of anhydrous gypsum, hemihydrate gypsum, and dihydrate gypsum as in Patent Document 4. Patent Document 6 describes a treatment method for dredging organic sludge accumulated on lakes and marshes and the seabed, treating it to make a solidified material suitable for the growth of seaweed and seaweed, and returning it to the seabed. Has been done. In the treatment of organic sludge, a solidifying agent composed of incinerator ash such as paper sludge, Portland cement, water absorption enhancer, polyvinyl alcohol resin and the like is used. According to this document, it is stated that gypsum may be selected as the water absorption enhancer, and that gypsum may be semi-hydrated gypsum, but anhydrous gypsum is particularly preferable. There is no explanation in the literature about what kind of action the water absorption enhancer exerts, but considering that anhydrous gypsum is recommended, the action required for the water absorption enhancer is not a hydration reaction. Conceivable.

The organic sludge can be treated by a conventional inorganic solidifying agent, an organic solidifying agent, or the like, and the solidifying agent described in Patent Document 4 can also treat the organic sludge. Further, although the treatment agents described in Patent Documents 1 to 3 are not intended for organic sludge, they can also be used for treating organic sludge. Further, the organic sludge can be treated by using the treatment agent used in the treatment methods described in Patent Documents 5 and 6. Then, in the treatment of such organic sludge, a conventional deodorizing method, for example, a chemical reaction method for deodorizing a bad odor with a deodorant can be combined. However, the treatment agents used in these treatment methods, hereinafter referred to as solidifying agents, have some problems to be solved with these solidifying agents. explain in detail. First, in any of the solidifying agents described in the literature, Portland cement is a material that exerts a solidifying action. Portland cement is a clinker obtained by baking clay with gypsum added to control the reaction rate of hydration and hardening. When water is added, its component, aluminate, first undergoes a hydration reaction. .. The hydrate of acicular crystals produced at that time is calcium sulfoluminate, that is, ettringite, which forms a network structure. This hydration reaction continues until the gypsum is consumed, and then the hydration reaction proceeds to alite, further to pelite, and ferrite. In this way, the strength is increased. However, there is a problem that it takes many days to complete. In the landfill of organic sludge, it is necessary for heavy machinery to run on the landfill and repeat the landfill, but if it takes days to obtain the required strength, the work efficiency will deteriorate. That is, these solidifying agents mainly exert a solidifying action on Portland cement, and have the first problem that it takes a long time to solidify organic sludge. The solidifying agent described in Patent Document 2 and the like also contains paper sludge ash and fly ash, which are also solidified by a hydration reaction, but are similar in that it takes a long time. Next, even Portland cement, which has a solidifying action, has a problem that it does not substantially solidify if only a small amount is added as compared with the water content. This is because the initially formed ettrin-guided network does not grow sufficiently and is therefore prone to destruction and does not solidify thereafter. Since organic sludge contains a large amount of water as described above even when it is made into a dehydrated cake, it must be added in a large amount in order to solidify it. Then, there is a second problem that the cost increases. When fly ash or the like is contained as the solidifying agent, there is a third problem that chromium, fluorine, boron and the like flow out and contaminate the soil and groundwater. Further, when gypsum is contained in the solidifying agent, there is a problem that hydrogen sulfide is generated. This is because sulfate-reducing bacteria inhabit groundwater, and gypsum is decomposed by the metabolism of these bacteria. This causes a fourth problem in which hydrogen sulfide, which is a new malodor, is generated. Further, these solidifying agents have a problem that even if they are combined with a conventional deodorizing method for deodorizing a bad odor, a sufficient deodorizing effect cannot be obtained, or if an effect is to be obtained, the cost increases. .. Both solidifying agents can solidify organic sludge with a certain degree of hardness, but unless the sludge is solidified until the water contained in the sludge is completely eliminated, this water continuously exudes and suppresses the volatilization of foul odors. Because it cannot be done. This is because if an attempt is made to suppress such a foul odor by using a deodorant, a large amount of deodorant corresponding to the large amount of water contained in the organic sludge is required. That is, there is a fifth problem that the bad odor cannot be appropriately suppressed.

The present invention has been made in view of the above-mentioned problems. Specifically, when it is added to organic sludge, kneaded and disposed of in landfill, it is practically used in a relatively short time at low cost. We would like to provide a sludge solidifying agent to be added to organic sludge, which has sufficient strength, does not pollute soil or groundwater, does not generate hydrogen sulfide, and can suppress the generation of malodor to some extent. I am aiming.

In order to achieve the above object, the present invention is configured as a powdery sludge solidifying agent to be added and kneaded when the organic sludge made into a dehydrated cake is landfilled, and is produced from the following materials. That is, the sludge solidifying agent of the present invention is produced from Portland cement, hemihydrate gypsum, and a powder deodorant containing a betaine compound as a main component, and the weight ratio of Portland cement to hemihydrate gypsum is 8: 2. Try to be ~ 6: 4. Then, if necessary, sodium silicate No. 3 or magnesium oxide may be added. Further, an admixture consisting of lignin sulfonic acid or a derivative thereof may be added.

Thus, the invention according to claim 1 is said to be organic when the organic sludge discharged into a dehydrated cake is landfilled in a urine treatment facility, a sewage treatment plant, a water purification plant, or the like in order to achieve the above object. A powdery sludge solidifying agent that is added to and kneaded with sex sludge to agglomerate, and the sludge solidifying agent is a powder deodorant containing Portland cement, hemihydrate gypsum, and a betaine compound as main components. It is composed as a sludge solidifying agent characterized in that the weight ratio of Portland cement to hemihydrate gypsum is 8: 2 to 6: 4.
The invention according to claim 2 is the sludge solidifying agent according to claim 1, wherein the sludge solidifying agent contains powdered sodium silicate No. 3 or magnesium oxide. Will be done.
The invention according to claim 3 is the sludge solidifying agent according to claim 1 or 2, wherein the sludge solidifying agent contains an admixture composed of lignin sulfonic acid or a derivative thereof. It is composed.

As described above, according to the present invention, when organic sludge discharged into a dehydrated cake at a sewage treatment facility, a sewage treatment plant, a water purification plant, etc. is landfilled, it is added to and kneaded with the organic sludge to form aggregates. It is configured as a powdery sludge solidifying agent to be converted. According to the present invention, the sludge solidifying agent is composed of Portland cement, hemihydrate gypsum, and a powder deodorant containing a betaine compound as a main component, and the weight ratio of Portland cement to hemihydrate gypsum is 8: 2. It is configured to be ~ 6: 4. When burying organic sludge in a landfill treatment plant, a backhoe is generally used, and when the sludge solidifying agent targeted by the present invention is added and kneaded, the backhoe is naturally used. Then, as will be described in detail later, the organic sludge becomes aggregated and the sludge solidifying agent is sprinkled on the surface thereof. Since it is only sprinkled, a relatively small amount of sludge solidifying agent is sufficient compared to the amount of organic sludge. With the sludge solidifying agent sprinkled on the surface in this way, the hydration reaction of hemihydrate gypsum first proceeds in a short time. That is, hemihydrate gypsum is temporarily dissolved in water, but rapidly changes to dihydrate gypsum by a hydration reaction and reprecipitates, and this becomes acicular crystals to form a network structure. Then, the surface layer of the aggregated organic sludge solidifies with a certain strength. That is, since the semi-hydrated gypsum promotes solidification to some extent, a certain degree of strength can be obtained in a short time, and the subsequent landfill treatment can be efficiently carried out. As for Portland cement contained in the sludge solidifying agent, the hydration reaction proceeds slowly, so that the surface layer of the finally aggregated organic sludge solidifies with a predetermined strength. In this solidification, the surface layer of the aggregated organic sludge is covered with hydrate with water trapped inside. Therefore, the water inside, which contains a foul odor, does not easily leak to the outside. In the vicinity of the surface layer, the betaine compound deodorizes the substance causing the malodor by a chemical reaction. Betaine compounds are deodorized by a chemical reaction with hydrogen sulfide and ammonia, which are the causative substances of malodor. As a result, the malodor generated from the organic sludge is suppressed. That is, the sludge solidifying agent according to the present invention does not solidify the entire organic sludge, but efficiently solidifies only the surface layer of the aggregated organic sludge and traps water inside, so that the amount used can be reduced. , Less deodorant is required. That is, the effect that the cost required for the treatment of organic sludge is small can be obtained. By the way, when gypsum is buried, there is a problem that hydrogen sulfide is generated by being decomposed by sulfate-reducing bacteria in the soil. However, since the sludge solidifying agent of the present invention contains alkaline Portland cement in a predetermined weight ratio, the gypsum The vicinity is maintained at a predetermined alkaline pH. Sulfate-reducing bacteria proliferate actively in acidic soil, but because they remain alkaline, their activity is suppressed and hydrogen sulfide is not generated. According to another invention, the sludge solidifying agent contains powdered sodium No. 3 silicate or magnesium oxide. As a result, the organic sludge containing a large amount of water is gelled, and the effect of preventing the distension and disintegration and redissolution of the aggregated organic sludge can be obtained. That is, the effect that the organic sludge is easily maintained as agglomerates can be obtained. In addition, No. 3 sodium silicate and magnesium oxide are weakly alkaline, which also has the effect of suppressing the activity of sulfate-reducing bacteria. According to yet another invention, the sludge solidifying agent comprises an admixture consisting of lignin sulfonic acid or a derivative thereof. With such an admixture, the sludge solidifying agent has improved fluidity and can uniformly coat the surface of agglomerated organic sludge.

(A) is a graph showing a change in pH when the amount of Portland cement added to 1 kg of organic sludge is changed, and (B) is a powder deodorant for 1 kg of organic sludge. It is a graph which shows the change of the odor when the addition amount of is changed. It is a photograph which shows the state of the experiment which added and kneaded the sludge solidifying agent and Portland cement which concerns on embodiment of this invention to organic sludge and solidified.

Hereinafter, embodiments of the present invention will be described. The sludge solidifying agent according to the present embodiment is a solidifying agent added to the organic sludge discharged at a sewage treatment facility, a sewage treatment plant, a water purification plant, etc. and made into a dehydrated cake when it is landfilled at a landfill treatment plant. Is. When treating such organic sludge, in the case of a conventional solidifying agent, it is added and kneaded and mixed so as to be uniform throughout the organic sludge, and the whole organic sludge is treated so as to be uniformly solidified. doing. On the other hand, the sludge solidifying agent according to the present invention takes a different approach in the treatment of organic sludge. Specifically, when a sludge solidifying agent is added to organic sludge and kneaded with a back hoe, the organic sludge is temporarily agglomerated to a predetermined particle size, but in kneading, the agglomerated organic matter is formed. Only the surface of the sludge is sprinkled with a powdery sludge solidifying agent. That is, the aggregated organic sludge is not further crushed by a backhoe and the sludge solidifying agent is not uniformly mixed throughout. Then, the aggregated organic sludge on which the sludge solidifying agent is sprinkled on the surface is made to solidify only the surface layer with the required strength within a predetermined time in a state where water is trapped inside, and the surface layer is deodorized. To do. As a result, although the amount of the sludge solidifying agent additive is small, the strength required for practical use can be obtained and the bad odor can be suppressed. After the required strength is obtained, the hydration reaction may proceed slowly and solidify with sufficient strength.

By the way, Portland cement is generally used as a water-curable cured product that is cured by a hydration reaction, but the object of the present invention cannot be achieved by this alone. That is, when only Portland cement, which requires a long hydration reaction, is used as the water-curable cured product, the Portland cement sprinkled on the surface of the aggregated organic sludge dissolves in water and permeates into the inside. This is because it ends up being. Then, it is not possible to solidify only the surface layer in a state where the water inside is trapped. In order to solidify only the surface layer, it is necessary to solidify the water-curable cured product before it penetrates into the inside. In other words, it is necessary for the hydration reaction to proceed within a short period of time while remaining on the surface layer. Therefore, the present inventors focused on hemihydrate gypsum as a water-curable cured product, and decided to add hemihydrate gypsum to Portland cement in the sludge solidifying agent according to the present invention.

By the way, even if the surface layer of aggregated organic sludge is solidified, a foul odor is generated from the surface layer. Therefore, it was decided to add a powder deodorant composed of a betaine compound capable of deodorizing malodorous substances in the solidified surface layer. From the above, it has been determined that the basic composition of the sludge solidifying agent according to the present invention is a powder deodorant composed of Portland cement, hemihydrate gypsum and a betaine compound.

In completing the sludge solidifying agent according to the present invention, it is necessary to determine the composition of Portland cement, hemihydrate gypsum and powder deodorant. First of all, it was decided to determine an appropriate mixing ratio of Portland cement, which is a water-curable cured product, and hemihydrate gypsum, and the inventors and others determined the necessary conditions in determining this. That is, the necessary conditions are that the time required for curing to the required strength is 5 hours or less, and that the required strength is 140 kPa in uniaxial compression strength. This is because if these conditions can be satisfied, only the surface layer can be solidified with the required strength in a state where the surface of the aggregated organic sludge is sprinkled with a sludge solidifying agent, and bloating and collapse can be prevented. Therefore, the inventors conducted an experiment in which Portland cement and hemihydrate gypsum were kneaded with a predetermined amount of water at various mixing ratios and cured, and the time required for curing with the above strength was measured. .. The results are shown in Table 1.

From this experiment, it was found that the condition can be satisfied if the mixing ratio of hemihydrate gypsum to Portland cement is 20% or more by weight, and the object of the present invention can be achieved. By the way, hemihydrate gypsum is more expensive than Portland cement. Therefore, in consideration of suppressing the price of the sludge solidifying agent, the blending ratio of the water-curable cured product in the sludge solidifying agent according to the present invention was determined as follows. That is, in the sludge solidifying agent according to the present invention, the mixing ratio of Portland cement and hemihydrate gypsum is 8: 2 to 6: 4 by weight.

By the way, hemihydrate gypsum is changed to dihydrate gypsum by hydration reaction, but dihydrate gypsum has a problem that it is decomposed by sulfate-reducing bacteria in acidic soil to generate hydrogen sulfide. It is known that this sulfate-reducing bacterium cannot grow in alkaline soil having a pH of 8 or higher, and the generation of hydrogen sulfide is suppressed. When the sludge solidifying agent according to the present invention, which comprises the mixing ratio of Portland cement and hemihydrate gypsum determined above, is added to and kneaded with weakly acidic organic sludge, it is necessary to confirm whether or not the pH is maintained at 8 or higher. There is. Among the materials constituting the sludge solidifying agent according to the present invention, dihydrate gypsum and powder deodorant are neutral, and Portland cement is the only material exhibiting alkalinity. Therefore, it is Portland cement that affects pH. Therefore, an experiment was conducted in which Portland cement was added in various amounts to the organic sludge discharged at the sewage treatment plant Y, kneaded uniformly, and the pH was measured. The result is shown in the graph of FIG. 1 (A). The horizontal axis is the amount of Portland cement added to 1.0 kg of organic sludge, and the vertical axis is the pH measured after kneading. If 15 g or more of Portland cement is added to 1.0 kg of organic sludge, the pH is maintained at 8.0 or more. That is, 15 kg or more of Portland cement may be added to 1 ton of organic sludge. The sludge solidifying agent according to the present invention is added so that the water-curable cured product composed of Portland cement and hemihydrate gypsum contained in the sludge solidifying agent weighs 35 kg to 40 kg with respect to 1 ton of organic sludge. Is assumed. As already determined, the mixing ratio of Portland cement and hemihydrate gypsum is 8: 2 to 6: 4 by weight. Then, about 25 kg of Portland cement is added to 1 ton of organic sludge. That is, it was confirmed that the pH was guaranteed to be maintained at 8.0 or higher, and that the problem of hydrogen sulfide generation by the sulfate-reducing bacteria did not occur.

Next, the blending of the powder deodorant composed of the betaine compound constituting the sludge solidifying agent according to the present invention is determined. We decided to use Epolion X-100, a product of Kyoritsu Seiyaku Co., Ltd., as the powder deodorant, and conducted an experiment to investigate how much of this should be added to organic sludge to obtain the deodorizing effect. went. First, in the sludge solidifying agent according to the present invention, it is assumed that the blending ratio of Portland cement and hemihydrate gypsum is 7: 3 by weight, and 36 kg of a water-curable cured product composed of these is added to 1 ton of organic sludge. bottom. At this time, it was decided to confirm how much the powder deodorant should be added to obtain the deodorizing effect. In the actual experiment, 25.2 g of Portland cement and 10.8 g of hemihydrate gypsum are added to 1 kg of organic sludge, for a total of 36 g. Then, these amounts of Portland cement and hemihydrate gypsum were mixed in advance with various powder deodorant formulations to obtain a sludge solidifying agent, which was then divided into plastic bags at 1 kg to make organic sludge. Addition and kneading. In this kneading, the organic sludge is only roughly kneaded so as to be aggregated so as to be equivalent to kneading with a backhoe, and the sludge solidifying agent is sprinkled on the surface of the aggregated organic sludge. I tried to do it. For such organic sludge, the odor index was measured 5 minutes after kneading. The odor index was measured at a distance of 1 cm from the organic sludge using the odor sensor XP-329IIIR manufactured by Shin Cosmos Electric Co., Ltd. The result is shown in the graph of FIG. 1 (B). The horizontal axis shows the amount of the powder deodorant blended, and the vertical axis shows the odor index. From this experiment, it was found that if 0.5 g or more of a powder deodorant was added to 1 kg of organic sludge, the odor index decreased from 27.5 to 22.5 and a sufficient deodorizing effect could be obtained. .. It was found that the deodorizing effect was enhanced by increasing the amount of the powder deodorant added to 1 kg of the organic sludge, but the deodorizing effect was hardly changed when the amount exceeded 10 g. From the above, it was set as a condition that 5 kg or more of a powder deodorant was added to 1 ton of organic sludge. That is, in the sludge solidifying agent according to the present invention, 0.5 parts by weight or more of the powder deodorant may be blended with respect to 35 to 40 parts by weight of the water-curable cured product composed of Portland cement and hemihydrate gypsum. ..

Summarizing the above, the sludge solidifying agent according to the present invention is composed of Portland cement, hemihydrate gypsum and powder deodorant, and the mixing ratio of the water-curable hardened material Portland cement and hemihydrate gypsum is by weight. The ratio is 8: 2 to 6: 4, and the amount of the powder deodorant is 0.5 parts by weight or more with respect to 35 to 40 parts by weight of the water-curable cured product. The basic structure of the sludge solidifying agent according to the present invention is as described above, but a predetermined amount of sodium silicate No. 3 or magnesium oxide may be blended if necessary. Since these absorb water in the organic sludge and gel, it has the effect of preventing distension and disintegration and redissolution of the aggregated organic sludge. Further, an admixture composed of lignin sulfonic acid or a derivative thereof may be added to the sludge solidifying agent according to the present invention. This is because the admixture improves the fluidity of the sludge solidifying agent and can uniformly coat the surface of the agglomerated organic sludge.

When the organic sludge is treated with the sludge solidifying agent according to the embodiment of the present invention, the surface layer is hardened in a short time in the aggregated state, and the shape of the organic sludge is in the aggregated state for a long period of time. Experiments were conducted to confirm that it was maintained.
experimental method:
100 g of organic sludge discharged at the sewage treatment plant Y and made into a dehydrated cake was placed in plastic bags A, B, and C.
To the plastic bag A, 3.7 g of the sludge solidifying agent according to the present embodiment is added, and the sludge solidifying agent is roughly stirred and mixed for 5 minutes so as to have a predetermined particle size of the sludge solidifying agent. The surface of the sludge was sprinkled with a sludge solidifying agent. In 3.7 g of the sludge solidifying agent according to the present embodiment, 2.5 g of Portland cement, 1.1 g of hemihydrate gypsum, and 0.1 g of powder deodorant are contained.
To the plastic bag B, add 10 g of Portland cement, stir and mix roughly for 5 minutes, and sprinkle the sludge solidifying agent on the surface of the aggregated sludge solidifying agent so as to have a predetermined particle size. I tried to be in the state of being.
Nothing was added to the plastic bag C, and the mixture was roughly stirred and mixed for 5 minutes so as to form aggregates having a predetermined particle size.
1 g of organic sludge was taken from the plastic bags A, B, and C, placed in beakers A, B, and C, respectively, and 95 cc of water was added to the beakers A, B, and C, respectively. After that, the beakers A, B, and C were each swayed horizontally 200 times. Photographs of beakers A, B, and C immediately after the rocking are shown in FIG. In the photograph, the beakers A, B, and C are the left end, the center, and the right end, respectively.
The beakers A, B, and C were left as they were, and were observed again one month later.
Experimental result:
Immediately after shaking, the organic sludge in beakers A and B was maintained in aggregates, whereas the organic sludge in beaker C swelled, collapsed in shape, and dissolved in water like a floc. rice field.
After being left for one month, the organic sludge in the beaker A was maintained in agglomerates, but most of the organic sludge in the beaker B was swollen and lost its shape. The organic sludge in the beaker C was dissolved in water like a floc and did not change.
Consideration:
The sludge solidifying agent according to the present embodiment can be solidified in a short time in an aggregated state of organic sludge even though only a small amount of 37 kg is added when converted to 1 ton of organic sludge, and for a longer period of time. It was confirmed that the shape could be maintained over the years. On the other hand, Portland cement, which is a conventional solid agent, was added in a large amount of 100 kg in terms of 1 ton of organic sludge, following the addition ratio conventionally used. However, the organic sludge was aggregated in a short time, but after a long period of time, the aggregated state was not maintained and it collapsed. From the above, it was confirmed that the sludge solidifying agent according to the present embodiment is superior to the conventional solidifying agent, and when treating organic sludge in a burial treatment plant, it can be retained for a long period of time in an aggregated state with a predetermined strength. did it.

At the burial treatment plant, an experiment was conducted in which the sludge solidifying agent according to the present embodiment was added to and kneaded with organic sludge to bury it. The added sludge solidifying agent according to the present embodiment was a mixture of 30 parts by weight of hemihydrate gypsum and 1.5 parts by weight of powder deodorant with respect to 70 parts by weight of Portland cement. 35-40 kg of the sludge solidifying agent according to the present embodiment was added per 1 ton of organic sludge and kneaded with a backhoe for 30 minutes. When the organic sludge was observed, it was formed into aggregates, and the sludge solidifying agent according to the present embodiment was uniformly sprinkled on the surface thereof. The organic sludge was then rapidly solidified and after 1 hour it was possible for the backhoe to run over it. That is, it was confirmed that the sludge solidifying agent according to the embodiment of the present invention can efficiently treat organic sludge.

Claims (3)

When organic sludge discharged into dehydrated cake is landfilled at a human waste treatment facility, sewage treatment plant, water purification plant, etc., it is added to and kneaded with the organic sludge to agglomerate it into powdery sludge solidification. It ’s a drug,
The sludge solidifying agent comprises Portland cement, hemihydrate gypsum, and a powder deodorant containing a betaine compound as a main component, and the weight ratio of Portland cement to hemihydrate gypsum is 8: 2 to 6: 4. A sludge solidifying agent characterized by that. The sludge solidifying agent according to claim 1, wherein the sludge solidifying agent contains powdered sodium silicate No. 3 or magnesium oxide. The sludge solidifying agent according to claim 1 or 2, wherein the sludge solidifying agent contains an admixture composed of lignin sulfonic acid or a derivative thereof.

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