JP2006051493A - System and method for treating sludge of sewage or organic waste water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a system for treating sludge humificating and stabilizing the sludge of sewage or organic waste water using soil microbial bacteria incubated/proliferated in a sludge incubation tank, removing a bad odor generated when sludge is treated and provided so as to utilize a cake of dewatered final sludge as a soil conditioner, and a method for treating the sludge. <P>SOLUTION: The system for treating the sludge comprises a biological reactor for biologically treating the sewage or the organic waste water, a sedimentation basin for settling the sewage or the organic waste water passing through the biological reactor, the sludge incubation tank for incubating the sludge transferred through an excess sludge transfer line from within the sludge settled in the sedimentation basin, a sludge transportation line for transporting a part of the sludge settled in the sedimentation basin, an incubator to be placed in the sludge incubation tank to incubate/proliferate a microbe, a concentrator for concentrating the sludge incubated in the incubation tank, and a dewaterer for dewatering the concentrated sludge. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a treatment system and treatment method for sludge generated during the treatment of sewage or organic wastewater, and more specifically, sewage or organic wastewater using soil microbial fungi cultured and grown in a sludge culture tank. The present invention relates to a sludge treatment system and a treatment method in which sludge is corroded and stabilized, malodors generated during sludge treatment are removed in advance, and a final sludge dewatered cake can be used as a soil improvement material.

  Sludge (raw sludge, surplus sludge) generated during the treatment of sewage and organic wastewater (livestock wastewater, manure, etc.) is composed of inorganic substances close to natural stone and fertilizer organic substances in addition to moisture. ing.

  In general, a peculiar odor is generated in the sewage treatment process, but this odor is caused by the inflowing sewage flowing in through the long sewage pipeline, while some organic matter is deposited in the pipeline and decays. It occurs frequently not only in the water treatment process but also in the sludge treatment process.

  In order to solve this bad odor, the upper part of the structure in the water treatment process is covered or covered, the generated bad odor is forcibly sucked and deodorized by the deodorizer, and then released into the atmosphere. However, the facility cost and the maintenance cost are high, which is accompanied by many operational difficulties.

  Therefore, a method has been proposed in which the amount of sludge is reduced and the sludge is stabilized to prevent spoilage, and the pathogenic microorganisms contained in the sludge are sterilized and made safe.

  In order to reduce the amount of sludge, concentration tanks and digesters are mainly used. Recently, the amount of sludge generated has increased due to the introduction of advanced treatment processes for removing nutrients. In addition, by staying in the concentration tank for a long time (12 hours or more), biologically treated phosphorus is released, the sludge becomes anaerobic, and the amount of agglomerated chemicals injected increases during dehydration. Dehydration efficiency is also decreasing.

  The two-stage anaerobic digestion method is used to stabilize and secure the sludge, but the digester equipment is very expensive and difficult to maintain, and the operation cost is high. And the efficiency with respect to operating costs is very low. In addition, the supernatant water and the desorbed filtrate generated in the above-described treatment process are very contaminated and are transferred to the sewage inflow part or the aeration tank inflow part to reprocess them. There are difficulties with this.

  Recently, a mechanical concentrator is used to solve the problem of such a concentration tank. Since the bad odor generated during the sludge treatment is very intense, it can be said that most of the bad odor generated from the sewage treatment plant is generated in this process. Therefore, a suction duct is installed in the odor generating part (primary sedimentation basin, concentration tank, concentrated sludge storage tank, dewatering ridge, etc.) to remove the odor, and a dehydrator for removing the inhaled odor components is used. This has the problem that it must be collected in the state where odors have already occurred, and in order to maintain the performance of the dehydrator, continuous management is required, which results in excessive maintenance costs. Is the actual situation.

  In addition, residents living in the vicinity of the treatment plant have experienced many difficulties due to bad odor, and a related law (Odor Control Law) has been enacted to regulate this. From now on, sewage treatment plants are also subject to regulation. Therefore, countermeasures against bad odors are necessary, and the dehydrated cake is not stabilized and is a habitat for harmful insects such as moths and mosquitoes. The fact is that it has caused a lot of damage.

  In order to solve such problems, bad odors generated in the sludge treatment process are inhaled by connecting ducts to the concentration tank, dewatering ridge, and dehydrated cake storage equipment, and the bad odor components are removed with a dehydrator. After that, the dehydrated cake that has been released to the atmosphere is transferred to a landfill and processed by landfill. However, odor emission due to re-rotation in the landfill and separation of moisture contained in the dewatered cake. Many health and safety problems such as leachate leakage due to water have occurred, which is another environmental pollution problem.

  The present invention has been made in view of such conventional problems, and the object of the present invention is to prevent malodors from spreading by removing in advance the malodorous components generated in the sludge treatment process of sewage or organic wastewater. The object is to provide a sludge treatment system and a treatment method.

  Another object of the present invention is to provide a sludge treatment system and treatment in which sludge is stabilized and made safe by the corrosion of sludge by soil microorganisms, and the finally obtained sludge dewatered cake can be used as a soil improvement material. It is to provide a method.

  Another object of the present invention is to provide a sludge treatment system and a treatment method capable of reducing the degree of contamination of supernatant water or return water separated during a sludge treatment process.

  Another object of the present invention is to provide a sludge treatment system and a treatment method capable of simplifying the sludge treatment process and reducing maintenance costs.

  In order to solve the above problems, according to one aspect of the present invention, a biological reaction tank for biologically treating inflowing sewage or organic wastewater, and sewage or organic wastewater that has passed through the biological reaction tank are precipitated. A sedimentation basin, a sludge culture tank for culturing sludge transferred through an excess sludge transfer line among sludges precipitated in the sedimentation basin, and a transport sludge line for transporting a part of the sludge precipitated in the sedimentation basin An incubator for culturing and growing soil microorganisms, a concentrator for concentrating sludge cultured in the culture tank, and dehydrating for dewatering sludge concentrated in the concentrator A sludge treatment system comprising a machine is provided.

  According to another aspect, the present invention also includes a step of biologically treating sewage or organic wastewater in a biological reaction tank, and a step of precipitating organic matter or nutrients treated in the biological reaction tank as sludge in a settling basin. And a part of the sludge settled in the settling basin is transported via a transport sludge transfer line, and the remaining sludge is a culture vessel for culturing and growing soil microorganisms via a surplus sludge transfer line. A stage for transferring and cultivating the sludge in a sludge culture tank, a stage for concentrating the cultured sludge with a concentrator, and dehydrating the concentrated sludge with a dehydrator, making it safe and stable without odors. A method for treating sewage or organic wastewater sludge comprising the step of obtaining a sludge dewatered cake is obtained.

  According to the sludge treatment system and treatment method of the present invention, malodorous components generated during the sludge treatment process of sewage or organic wastewater can be removed in advance, and the sludge is made safer and stabilized by the corrosion of the sludge by soil microorganisms. Thus, the finally obtained sludge dehydrated cake can be used as a soil conditioner.

  It also reduces the contamination of the supernatant water or return water separated during the sludge treatment process, reduces the amount of flocculant used during sludge dewatering, simplifies the existing sludge treatment process, and reduces maintenance costs. It can be saved.

  Hereinafter, the sludge treatment system of the present invention will be described in detail with reference to the accompanying drawings.

  FIG. 1 is a process flow diagram of sewage or organic wastewater sludge treated according to the present invention. As shown in FIG. 1, the sludge treatment system of the present invention precipitates a biological reaction tank 2 for biologically treating incoming sewage or organic wastewater, and sewage or organic wastewater that has passed through the biological reaction tank 2. A settling basin 3 to be transferred, a sludge culture tank 4 for culturing sludge transferred through an excess sludge transfer line 15 among sludges settling in the settling basin 3, and a part of the sludge settling in the settling basin 3 is conveyed. Conveying sludge transfer line 16 to be carried out, an incubator 11 installed in the sludge culture tank 4 for culturing and growing soil microorganisms, a concentrator 5 for concentrating sludge cultured in the culture tank, and the concentrator A dehydrator 6 is provided for dewatering the sludge concentrated in (1).

  In the sludge treatment system of the present invention, as the incubator 11 installed in the sludge culture tank 4, a ground type and underwater type combined incubator, or an underwater type single incubator can be used.

  The sludge treatment system of the present invention can treat sludge generated from either sewage or organic wastewater. Here, the organic waste water refers to livestock waste water or manure.

  When organic wastewater is treated using the treatment system of the present invention, treated water discharged through the settling basin 3 can be treated in conjunction with sewage.

  FIG. 2 is a flow chart of sludge treatment when treating a small volume of sewage. FIG. 3 is a flow chart of sludge treatment when treating sewage of medium volume. FIG. 4 is a flow chart of sludge treatment when treating large volumes of sewage.

  In particular, when sewage is treated in the present invention, as shown in FIGS. 2 to 4, the pre-settlement basin 1 is physically passed through the sedimentation process before passing through the biological reaction tank 2. Furthermore, it further includes a raw sludge transfer line 14 for transferring raw sludge generated through the precipitating basin 1 to the culture tank 4.

  As shown in FIG. 3, when treating a middle volume of sewage, it further includes a concentrator 8 in order to reduce the water content of the raw sludge settled in the first settling basin 1, and the concentrated sludge is raw sludge. It is transferred to the culture tank 4 via the transfer line 14.

  Moreover, as shown in FIG. 4, when processing a large volume of sewage, the concentration tank 7 which concentrates the raw sludge settled in the said precipitating basin 1, and the sludge concentrated in the said concentration tank are digested. Digesting tanks 9 and 10 are further included, and the sludge that has passed through the concentration tank 7 and the digesting tanks 9 and 10 is transferred to the culture tank 4 via the raw sludge transfer line 14.

  Next, the sludge treatment method of the present invention will be described in detail with reference to the accompanying drawings.

  In the sludge treatment method of the present invention, the inflowing sewage or organic waste water is biologically treated in the biological reaction tank 2, and the organic matter or nutrients treated in the biological reaction tank 2 is sludged in the sedimentation basin 3. Of the sludge precipitated in the sedimentation basin 3, a part of the sludge is transported via the transport sludge transport line 16, and the remaining sludge is transferred to the surplus sludge transport line 15 for soil microorganisms. A step of transferring and culturing to a sludge culture tank 4 with an incubator 11 for culturing and proliferation, a step of concentrating the cultured sludge with a concentrator 5, and a dehydrator 6 dehydrating the concentrated sludge The method includes the step of obtaining a sludge dehydrated cake that is safe and stabilized without bad odor.

  In the sludge treatment method of the present invention, the inflowing sewage or organic wastewater passes through the biological reaction tank 2 and undergoes biological treatment to separate organic matter or nutrient salts.

  Here, various known methods are used for the biological treatment method.

  The organic matter or nutrients separated in the above step is separated into solid and liquid in the sedimentation basin 3, the treated water is discharged, and a part of the sludge sinking to the bottom is transferred to the sludge culture tank 4 through the surplus sludge line 15. .

  A part of the sludge settled in the settling basin 3 is transported via a transport sludge transfer line 16.

  The sludge cultured in the sludge culture tank 4 is concentrated by the concentrator 5 and dehydrated by the dehydrator 6. As a result, a sludge dewatered cake that has no foul odor and is safe and stabilized can be obtained.

  An incubator 11 is installed in the sludge culture tank 4. The incubator 11 removes malodorous substances generated from the sludge and stabilizes and stabilizes the sludge by creating the same environmental conditions as the optimum soil necessary for culturing and growing the soil microorganisms.

  The incubator 11 used in the present invention is filled with a filler, which is composed of sludge crystals treated by the action of soil, humus soil, and soil-borne microorganisms, and has an irregular shape. Pellets compressed into a lump, cylinder, sphere, and the like, and siliceous pumice, zeolite, or crushed stone of the barley stone series. Such packing in the incubator functions to create environmental conditions similar to soil in which soil microorganisms are in a natural state.

Soil microorganisms cultured and propagated in this process are dominated by Bacillus, Thiobacillus, Pseudomonas, Micrococcus, Acinetobacter, Aeromonas, etc. .
The concentration of dissolved oxygen in the culture tank 4 maintains a facultative state of 0.1 to 0.5 mg / L, and the microorganism concentration is 6,000 to 12,000 mg / L.

  In order to maintain the said permeable state in the culture tank 4, the normal diffuser which blows the air in air | atmosphere in the culture tank 4 with a normal air blower, and disperse | distributes the air which flows in via a air blower. It is installed in the culture tank 4. In addition, when the oxygen consumption rate of the inflowing sludge becomes low, the concentration of dissolved oxygen becomes too high, so that the operation of the blower is unavoidable in order to maintain the above-mentioned permeable state. In order to prevent solid-liquid separation due to sludge sedimentation, a stirrer for stirring the inside of the culture tank is installed.

  The pH in the culture tank 4 of the present invention is normal biological treatment conditions, that is, pH 6-8.

  On the other hand, the sludge stays in the culture tank 4 for 1.5 to 2 days.

  In the sludge treatment method of the present invention, when sewage is treated, it passes through the sedimentation raw sludge transfer line 14 after passing through the sedimentation process in the pre-precipitation basin 1 before the inflowing sewage passes through the biological reaction tank 2. A step of transferring to the culture tank 4.

  This is suitable for application to a small-capacity sewage treatment plant, and as shown in FIG. 2, raw sludge settled in the pre-settlement basin 1 is transferred to the culture tank 4 via the raw sludge transfer line 14, Surplus sludge generated through the biological reaction tank 2 and the sedimentation basin 3 flows into the culture tank 4, and mixed sludge of raw sludge and surplus sludge is cultured in the culture tank.

  Further, as shown in FIG. 3, in the sludge treatment method of the present invention, the raw sludge precipitated in the precipitating basin 1 is reduced in water content using a concentrator 8 and then the raw sludge is transferred to the raw sludge transfer line 14. The method may further include a step of transferring the sludge to the sludge culture tank 4 via the slag. This is suitable for medium capacity sewage treatment plants.

  Moreover, as shown in FIG. 4, in the sludge treatment method of the present invention, the raw sludge precipitated in the pre-precipitation basin 1 is concentrated in the concentration tank 7, digested in the digestion tanks 9 and 10, and then the raw sludge transfer line. 14 may be further transferred to the sludge culturing tank 4 via 14. This is suitable for application to large-capacity sewage treatment plants.

  Next, the malodor removal principle in the sludge treatment method of the present invention will be specifically described.

In general, malodor is a by-product generated by the degradation of proteins, amino acids, nucleic acid substances, etc. contained in organic matter, and is produced by the process of aminating protein by ammoniation (NH ₃ ) and inorganic Hydrogen sulfide (H ₂ S) generated by the chemical action acts as a main cause of malodor.

  When sludge containing raw malodorous substances (raw sludge, surplus sludge, digested sludge, etc.) is transferred to the sludge culture tank 4, the malodorous substances such as ammonia, hydrogen sulfide, methyl sulfide, methyl disulfide, methyl mercaptan, etc. Soil microorganisms adsorb, agglomerate and bind to organic nutrients such as organic matter, nitrogen and phosphorus in sewage to remove the malodorous substances and the like through biological reaction processes such as polycondensation, oxidation and reduction. In other words, the malodor of ammonia nitrogen in the nitrogen system is used as a protein in the biocomposition of soil microorganisms due to biosorption by soil microorganisms and physical adsorption by dissolution in water. Hydrogen sulfide, methyl sulfide, methyl disulfide, methyl mercaptan The sulfur component in the malodor of the sulfur compound system such as is oxidized and removed by Thiobacillus as a soil microorganism that removes the sulfur component.

  In particular, the sludge culture tank 4 of the present invention produces an odor similar to the odor of soil. This is due to the large amount of Actinomyces odorifer, which has a special odor of soil, acting on the odor of soil. Induce.

  Among the soil microorganisms (facultative anaerobic fungi) that are occupied as dominant species in the sludge treatment method of the present invention, such as Bacillus, Pseudomonas, Alcaligenes, Beggiatoa, etc. Bacteria, radiation fungi such as Streptomyces, Actinomyces, and microorganisms such as yeasts fundamentally remove malodorous components.

  In the sludge treatment method of the present invention, the sludge is stabilized by undergoing a process in which organic matter is corroded by soil microorganisms, and since it does not decay in natural systems, there is no odor emission, and a continuous corrosion process is performed. Eventually, it can be used as a soil conditioner by changing to a soil-like substance.

  Organic matter is a brown or black-brown amorphous polymer material that is produced by polycondensation while repeatedly decomposing and synthesizing by the action of soil microorganisms, and the degradation product is partially synthesized and fixed to the living body. It is transformed into environmental organic matter by the effects of waste, secretions, microbial fluids, etc. due to its biological activity, and it is decomposed by the next generation of microorganisms. Since the organic matter is polymerized by repeating such a process, the change is closely related to the distribution or density change of the microorganism.

  As organic substances become polymerized and the number of substances that are difficult to decompose increases, the types of microorganisms that can be decomposed and used decrease, and at a certain stage, general organisms can no longer be used. It is necessary to cultivate and grow microorganisms capable of removing

  In order to induce and cultivate microorganisms capable of removing persistent organic substances, that is, soil microorganisms, it is necessary to continuously convert the soil microorganisms to organic aromatic metabolites. In particular, a group of bacteria with enhanced aromatic constituent metabolism that reproduces naturally from outside the control system (bacteria group in symbiotic relationship with soil anaerobic bacteria) can be used as inoculum under certain conditions, It is necessary to add a substance containing such a metabolite outside the system.

  The use of special corrosives as common additives has been established with economical and synthetic techniques. In this case, the corrosive is a general term for the corrosive process substances including the metabolism and secretion of microorganisms, and substitutes the high quality corroded sludge generated by long-term operation treatment in a good treatment system. It is also possible in some cases.

  In addition, if soil microorganisms that have expressed aromatic constituent metabolism are left in an artificial environment for a long time, they will be denatured into non-aromatic metabolism, so this denaturation should not occur or the constant addition of inducers should be avoided. Therefore, the incubator 11 is required for the purpose of creating environmental conditions for maintaining the aromatic metabolic function of soil microorganisms that reproduce in the apparatus.

  Since the active soil is built in the incubator 11 used in the present invention, a group of soil microorganisms having a specific metabolic function is selectively cultured and grown to activate the aromatic metabolic function.

  The corrosive reaction is performed by integrating substances, microorganisms, and water. Substances, microorganisms, and water in this process have the property of trying to maintain their state, although they differ to some extent.

  The sludge treatment process of the present invention is characterized by the effective use of a corrosion precursor and a corrosive substance as one utilizing the properties.

  In general, when microorganisms are used, the microorganisms are first adjusted in the environment by releasing metabolites in an environment different from their optimal environment. Even so, if the metabolites are released above the limit, they die or become spores, and even if they are not annihilated, the density of the microorganisms decreases, and a certain order of the entire group of microorganisms in a complex interrelationship environment is achieved. It takes some time to build.

  The environmental adjustment by the corrosion precursor is first performed by a chemical reaction between organic substances including metabolites. Thereby, there are few direct environmental changes with respect to the various bacterial group which has a fixed order in a precursor and exists in high density.

  Even if there is a large change, microorganisms can respond as a group, and the distribution of microorganisms naturally changes.

  Sludge that has undergone the above-mentioned corrosive process is stabilized, but Escherichia coli, spoilage bacteria, staphylococci, etc. are sterilized and controlled by the corrosion precursor, and the sludge can be made safe. Can contribute.

2 is a process flow diagram of sewage or organic wastewater sludge treated according to the present invention. 4 is a flow diagram of a small volume sewage sludge process treated by the present invention. 3 is a flow diagram of a medium volume sewage sludge process treated by the present invention. 3 is a flow diagram of a large volume sewage sludge process treated by the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Precipitation pond 2 Biological reaction tank 3 Sedimentation basin 4 Sludge culture tank 5 Concentrator 6 Dehydrator 7 Concentration tank 8 Concentrator 9, 10 Digestion tank 11 Incubator 14 Raw sludge transfer line 15 Surplus sludge transfer line 16 Conveyance sludge transfer line

Claims (10)

A biological reactor for biological treatment of sewage or organic wastewater;
A sedimentation basin for precipitating sewage or organic wastewater that has passed through the biological reaction tank;
Of the sludge settled in the settling basin, a sludge culture tank for culturing sludge transferred through an excess sludge transfer line;
A transport sludge line for transporting a portion of the sludge settled in the settling tank;
Pellets and siliceous pellets, which are installed inside the sludge culture tank, are composed of sludge crystals that have been treated by the action of soil, humus, and soil microorganisms, and are compressed into irregular lump, cylinder, sphere, etc. An incubator filled with crushed stones of pumice, zeolite or barley stone system to culture and grow soil microorganisms;
A concentrator for concentrating sludge cultured in the culture tank;
A sewage or organic wastewater sludge treatment system comprising a dehydrator for dewatering sludge concentrated by the concentrator. A pre-settling basin for physically precipitating sewage or organic wastewater is further arranged in the front stage of the biological reaction tank,
The sewage or organic wastewater sludge treatment system according to claim 1, further comprising a raw sludge transfer line for transferring raw sludge generated through the precipitating basin to the culture tank.   2. The sewage or organic wastewater sludge treatment system according to claim 1, wherein the incubator is an above-ground and underwater combined incubator or an underwater single incubator. Biologically treating sewage or organic wastewater in a biological reactor;
Precipitating organic matter or nutrients treated in the bioreactor as sludge in a sedimentation basin;
Among the sludge settled in the settling basin, some sludge is transported via a transport sludge transport line, and the remaining sludge is equipped with an incubator for culturing and growing soil microorganisms via the surplus sludge transport line. Transferring to a sludge culture tank and culturing;
A concentration step of concentrating the cultured sludge with a concentrator;
A method for treating sewage or organic wastewater sludge, comprising the step of dehydrating the concentrated sludge with a dehydrator to obtain a sludge dehydrated cake that is safe and stabilized without bad odor. Since a pre-precipitation pond is further provided in the previous stage of the biological reaction tank,
Before the biological treatment step, the step of physically precipitating incoming sewage or organic wastewater in the pre-settling basin and transferring the precipitated raw sludge to the sludge culture tank via a raw sludge transfer line The sewage or organic wastewater sludge treatment method according to claim 4, further comprising:   The concentration of dissolved oxygen in the culture tank is maintained at a facultative state of 0.1 to 0.5 mg / L, and the microorganism concentration is 6,000 to 12,000 mg / L. Sewage or organic wastewater sludge treatment method.   The sewage or organic wastewater sludge treatment method according to claim 4, wherein the sludge stays in the culture tank for 1.5 to 2 days.   The sewage or organic waste water according to claim 4, further comprising a step of transferring the raw sludge precipitated in the pre-settling basin to the sludge culture tank after reducing the water content using a concentrator. Sludge treatment method.   9. The method according to any one of claims 4 to 8, further comprising a step of concentrating the raw sludge precipitated in the pre-precipitation basin in a concentration tank, digesting the raw sludge in the digestion tank, and then transferring the sludge to the sludge culture tank. The method for treating sewage or organic wastewater sludge according to item 1. The incubator is composed of sludge crystals treated by the action of soil, humus soil, soil microorganisms and compressed into irregular lump, cylinder, sphere, etc., siliceous pumice, zeolite or 5. The method for treating sewage or organic wastewater sludge according to claim 4, wherein the sewage or organic wastewater sludge is filled with crushed stone of the barley stone system.

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