JP4746798B2 - Contaminant purification method and purification device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a purification method and a purification device for contaminants, and more particularly to a purification method and a purification device suitable for purification of soil and water contaminated with organic compounds containing a large amount of chlorine in molecules such as dioxins.
[0002]
[Prior art]
Of the pollutants discharged through our daily lives and industrial activities, for pollutants that contain organic compounds containing many chlorine in their molecules as pollutants, the Special Measures Law for Countermeasures against Dioxins for Solids such as Soil As a result of such enforcement, emission regulations have been strengthened according to water quality environmental standards, etc. for liquids such as wastewater, and their emissions are regulated.
[0003]
On the other hand, a large amount of these contaminants accumulated up to now is expected to be treated with inexpensive and reliable techniques and methods that do not cause secondary contamination during the process. Yes. As such a technique and method, a purification method that renders the contaminants harmless by a decomposition reaction by microorganisms is expected as an effective technique.
[0004]
In the purification method using microorganisms, the type and usage of microorganisms to be used are selected mainly depending on the types of contaminants contained in the contaminants. For example, an organic compound containing a large amount of chlorine in a molecule is generally a chemically and physically very stable substance. As a microorganism that degrades such a compound, a microorganism that cleaves chlorine chains is used.
[0005]
As a microorganism that cleaves a chlorine chain, for example, Pseudomonas bacteria that are thermophilic bacteria, a kind of pathogenic microorganisms (Pseudomonas aeruginosa), and anaerobic microorganisms are known. In addition, for example, shimeji bacterium, white rot fungus, and filamentous fungus, which are thermophilic bacteria, are known as microorganisms that decompose pollutants including chlorine compounds such as dioxins.
[0006]
In addition to this, a technique for utilizing the difference in characteristics between aerobic microorganisms and anaerobic microorganisms and combining them to efficiently decompose and purify contaminants has been conventionally known. For example, as such a technique, as disclosed in JP-A-9-16497, in a wastewater treatment apparatus that performs wastewater treatment by an anaerobic aerobic method combining an anaerobic tank and an aerobic tank, air is used as a raw material. As an aeration gas for the aerobic tank, an oxygen-enriched gas obtained from an air separation device that separates oxygen and nitrogen and generates an oxygen-enriched gas and a nitrogen-enriched gas is used. There is known a waste water treatment apparatus using an anaerobic aerobic method characterized by using as a diffused gas in the anaerobic tank.
[0007]
[Problems to be solved by the invention]
Pseudomonas is an excellent microorganism for cleaving chlorine chains, but it is a normal temperature bacterium, and in the dechlorination reaction using this bacterium, the chlorine chain is cleaved at the final stage of decomposition of contaminants. It may take months, and there is a problem that even if it is used in the above-described purification method, it cannot withstand industrial use. In addition, aerobic microorganisms such as white rot fungi which are room temperature bacteria also have a problem that the decomposition rate is very slow and they cannot be industrially endured in the contaminant purification method. That is, in the purification of contaminants containing chlorine compounds, it is difficult to decompose chlorine compounds using room temperature bacteria from the viewpoint of industrially purifying contaminants.
[0008]
The wastewater treatment apparatus supplies an oxygen-poor gas to the anaerobic tank as an aeration gas, and supplies an aeration gas rich in oxygen to the aerobic tank, thereby realizing a suitable environment in both tanks. Although the apparatus is excellent in terms of the point, there is still room for improvement with respect to the problem of the purification method using room temperature bacteria that the decomposition rate is very slow and cannot be used industrially.
[0009]
The present invention has been made in view of the above matters, and in purifying contaminants containing a chlorinated organic compound by a microbial decomposition reaction, the microbial decomposition reaction rate is further increased and the reproducibility of the microbial reaction is ensured. Another object of the present invention is to provide a purification method and a purification device that are more effective for decomposing the compounds in pollutants below the environmental standard value.
[0010]
[Means for Solving the Problems]
The present invention provides a method and apparatus for decomposing a contaminant containing a chlorine compound using a microorganism having a high optimum temperature for decomposing a chlorine compound, as a means for solving the above-mentioned problems. The present invention provides a means for increasing the probability of contact with a compound and decomposing more rapidly, and a means for decomposing a chlorine compound stepwise and rapidly using the characteristics of the microorganism used.
[0011]
That is, the present invention relates to a pollutant purification method for decomposing and purifying contaminants containing chlorine compounds by microorganisms in a system in which the temperature is adjusted, comprising an adsorption component for physically adsorbing chlorine compounds, and a chlorine compound. A pollutant purification method (hereinafter referred to as this purification method) characterized in that a microorganism having an optimum temperature for decomposition of at least 60 ° C. is present in the contaminant and the contaminant flows in the system. Also referred to as “first purification method”.
[0012]
According to the purification method, the microorganism decomposition reaction rate can be further increased by using a microorganism having a higher optimum temperature than that of the normal temperature bacteria, and the purification of the contaminants by the microorganism can be industrially utilized. It becomes possible to be a method. In addition, the use of microorganisms with a high optimum temperature eliminates the action of germs such as room temperature bacteria, and the degradation reaction by microorganisms with a high optimum temperature is further purified, thus ensuring the reproducibility of the microorganism reaction. It becomes possible. Furthermore, the presence of an adsorbing component that physically adsorbs the chlorine compound in the microbial decomposition reaction system makes it easier for the microorganisms to settle on the adsorbing component, and the chlorine compound is concentrated on the adsorbing component. It becomes possible to further improve the contact probability.
[0013]
The present invention also relates to a contaminant purification method for decomposing and purifying contaminants containing chlorine compounds by microorganisms in a system in which the temperature is adjusted, and is contaminated by microorganisms for dechlorination having an optimum temperature of 60 ° C. or higher. Dechlorination process that decomposes chlorine compounds in waste and removes chlorine from pollutants, and compounds in pollutants from which chlorine has been removed in the dechlorination process And a compound decomposing step for decomposing by the method (hereinafter, this purification method is also referred to as “second purification method”).
[0014]
According to the purification method, the microorganism decomposition reaction rate can be further increased by using a microorganism having a higher optimum temperature than that of the normal temperature bacteria, and the purification of the contaminants by the microorganism can be industrially utilized. It becomes possible to be a method. In addition, the use of microorganisms with a high optimum temperature eliminates the action of germs such as room temperature bacteria, and the degradation reaction by microorganisms with a high optimum temperature is further purified, thus ensuring the reproducibility of the microorganism reaction. It becomes possible.
[0015]
Further, according to the purification method of the present invention, since the dechlorination step is performed prior to the compound decomposition step, it is possible to prevent the inactivation of the compound-decomposing microorganisms due to the presence of chlorine. It is more effective in decomposing chlorine compounds below environmental standards.
[0016]
Contaminants applied to the purification method of the present invention may be composed of solids such as soil, or may be composed of liquids such as drainage. A slurry containing both of them may be used. In addition, gaseous contaminants are adsorbed on adsorbents such as soil and other adsorbents containing clay minerals, zeolites with a predetermined particle size or surface shape, or processed zeolite, or water. It is possible to purify in the present invention by a method such as absorption in the present invention.
[0017]
Chlorine compounds contained in pollutants are generally chemically and physically stable, and many of them are difficult to treat properly by ordinary treatment such as incineration. Is possible. Examples of such a chlorine compound include organic compounds containing chlorine in the molecule, such as dioxins, PCB, trichlorethylene, and perchlorethylene.
[0018]
In the present invention, the optimum temperature refers to an optimum temperature for the growth of microorganisms, and is an optimum temperature for a microbial decomposition reaction. If the optimum temperature of the microorganism used in the present invention is lower than the above temperature, the reaction rate of the microorganism may be reduced and it may not be able to withstand industrial use. May not be secure.
[0019]
The microorganism used in the present invention is capable of decomposing the chlorine compound itself, dechlorinating the chlorine compound, and decomposing the compound after dechlorination. From the viewpoints of speeding up the microbial decomposition reaction and purifying the microbial decomposition reaction, A microorganism having an optimum temperature of at least 60 ° C. can be used regardless of whether it is an aerobic microorganism or an anaerobic microorganism. In the first purification method, a microorganism that decomposes the chlorine compound itself is used.
[0020]
In the first purification method, it is preferable to use an aerobic microorganism having an optimum temperature of 65 ° C. or higher under the condition that oxygen is supplied into the pollutant system by the oxygen supply means. According to such a purification method, unlike the use of anaerobic microorganisms, it is not necessary to take measures against the invasion of oxygen into the system, so that the configuration of the purification device and the operation of the purification method are simplified. It is suitable for realizing the conversion. Examples of suitable microorganisms in the purification method include Bacillus midousuji.
[0021]
The adsorbing component used in the present invention has a property of physically adsorbing chlorine compounds and has a form in which microorganisms can be implanted, and examples thereof include soil particles, and more specifically, contamination. Examples thereof include soil particles in soil and soil particles in slurry-like contaminated water containing contaminated soil.
[0022]
In the present invention, it is sufficient that the adsorbing component capable of sufficiently bringing the chlorine compound and the microorganism into contact with each other is contained in the contaminant. However, the chlorine compound is sufficiently adsorbed and the microorganism is implanted, It is preferable to further add an adsorbent to the microorganism reaction system in order to further increase the chance of contact between the microorganism and the microorganism. Examples of such an adsorbent include clay minerals having a suitable surface state, particle size, and the like, or separated or processed, and are not particularly limited in terms of production method, material, form, and the like. A preferable adsorbent includes zeolite having pores having a pore size distribution corresponding to 1 or more times the molecular size of the chlorine compound. Although the form of the adsorbent will be described later, various forms can be adopted depending on the form of contaminants, the characteristics of microorganisms, and the like.
[0023]
In addition, the molecular dimension of a chlorine compound means the magnitude | size calculated | required from a chemical structural formula or a three-dimensional structure of a molecule | numerator. The pore size distribution is the pore size distribution of the pores on the surface of the adsorbent, and is represented by the center value of the pore size distribution in the present invention. That is, the range of the pore size distribution as described above means that the center value of the pore size distribution is in that range. The pore size distribution with respect to the molecular size of the chlorine compound varies depending on the adsorbent material, adsorption capacity, affinity with the chlorine compound, etc., but if the pore size distribution is too small, the chlorine compound is adsorbed on the adsorbent. If the pore size distribution is too large, the adsorbent may not be able to capture the chlorine compound. From such a viewpoint, the adsorbent suitable according to the present invention is, for example, the pore size distribution relative to the molecular size of the chlorine compound. Natural zeolite that is 3 to 5 times is mentioned.
[0024]
In the present invention, the molecular size of a chlorine compound can be determined from a chemical structural formula or a three-dimensional structural formula of a molecule. Further, the pore size distribution of the adsorbent can be obtained by obtaining an adsorption isotherm by experiments and applying capillary condensation theory to the adsorption isotherm. Further, the pore size distribution can be adjusted by a method of selecting a suitable pore size distribution from adsorbents having a known pore size distribution or a method of mixing two or more types of suitable pore size distributions. is there.
[0025]
In the first purification method, the contaminants containing the adsorbing components such as the microorganisms and the adsorbent described above are flowed in the system in which the temperature is adjusted. With respect to this flow, it is preferable that the pollutants that flow through a predetermined position in the system pass. Examples of the predetermined position in the system include a fixing position of the adsorbent when the adsorbent is fixed in the system, a gas contactor described later, and the like.
[0026]
In the first purification method, when an aerobic microorganism is used as the microorganism, the flow of contaminants in the gas contactor optimizes the oxygen concentration in the system that affects the microbial decomposition reaction. preferable. The gas contactor will be described later, but is not particularly limited as long as it forms a passage that enhances the contact between the fluid and the gas.
[0027]
In the second purification method, a dechlorination microorganism that dechlorinates a chlorine compound and a compound decomposition microorganism that decomposes a compound in a contaminant are used. As the dechlorination microorganism, any one of an anaerobic microorganism and an aerobic microorganism can be used as long as the optimum temperature is 60 ° C. or higher and the chlorine compound in the contaminant is decomposed. Moreover, as long as the said microorganisms for compound decomposition | disassembly are microorganisms which have the optimal temperature of 65 degreeC or more and decompose the compound in the contaminant from which chlorine was removed, either aerobic microorganisms or anaerobic microorganisms should be used. Can do. In addition, the compound in the contaminant in said 2nd purification method means the compound of the structure where chlorine was removed from the said chlorine compound by the dechlorination process.
[0028]
By the way, aerobic microorganisms can only operate in the presence of oxygen, but anaerobic microorganisms tend to be inactive in the presence of oxygen. Therefore, in the second purification method of the present invention, an anaerobic microorganism and an aerobic microorganism are selectively used in each step (for example, if an anaerobic microorganism is used in one step, an aerobic microorganism is used in the other step), It is preferable because the microbial decomposition reaction can be advanced to the next step without performing a step such as sterilization. When focusing on the characteristics of microorganisms, it is known that anaerobic microorganisms are advantageous for dechlorination reactions, and it is known that aerobic microorganisms are advantageous for compound decomposition reactions. Therefore, it is preferable to use anaerobic microorganisms and aerobic microorganisms in each step.
[0029]
From these viewpoints, in the second purification method, in the dechlorination step, anaerobic microorganisms are used as the dechlorination microorganisms, and the chlorine compounds in the contaminants are removed in the system in which oxygen is removed by the oxygen removing means. It is a step of decomposing, wherein the compound decomposing step is a step of decomposing the compound in a system in which an aerobic microorganism is used as a compound decomposing microorganism and oxygen is supplied by an oxygen supply means. It is more preferable in purifying.
[0030]
In the case where the same microorganism (ie, anaerobic and anaerobic, or aerobic and aerobic) is used in both steps, a sterilization step such as heat treatment may be performed between both steps.
[0031]
As the dechlorination microorganism, a microorganism capable of cleaving a chlorine chain in a chlorine compound is used. For example, Clostridium pastorianum can be exemplified as an anaerobic microorganism.
[0032]
The compound-decomposing microorganism varies depending on the composition of elements other than chlorine contained in the compound, but in the case of decomposing the previously exemplified chlorine compound, oxygen crosslinking, benzene ring cleavage, and alkyl group opening chain decomposition, etc. Microorganisms that perform the above can be used preferably. Examples of the compound-decomposing microorganism used in the second purification method include Clostridium pastorianum and the like if they are anaerobic microorganisms, and Bacillus midousuji and the like if they are aerobic microorganisms.
[0033]
In the purification method of the present invention described above, it is preferable to include an exhaust gas treatment step for treating a gas discharged along with a microbial decomposition reaction, and it is particularly preferable to include an exhaust gas treatment step for treating a gas discharged in the dechlorination step. . As the gas discharged in the purification method of the present invention, for example, a gas containing chlorine, other gas generated in accordance with the dechlorination reaction, for example, lower hydrocarbons such as methane, chlorine, carbon, hydrogen, etc. Examples thereof include a molecule in which one or more elements constituting a chlorine compound are combined with oxygen.
[0034]
Therefore, the exhaust gas treatment step is preferably a treatment capable of detoxifying these gases. If chlorine gas is used, a step of fixing to salt by reaction with alkali is desirable, and it is adsorbed by an adsorbent such as calcium carbonate. Examples of the process may include a recovery process, a combustion process, a decomposition process in the presence of a catalyst such as nickel, an adsorption process using an adsorbent such as activated carbon, and the like.
[0035]
In the present invention, part or all of the gas treated in the above-described exhaust gas treatment process may be returned to the microbial decomposition reaction system, for example, the gas treated in the exhaust gas treatment process for the exhaust gas in the dechlorination process. A configuration for returning to the dechlorination reaction system is preferable in maintaining the environment in the reaction system.
[0036]
In addition to the above-described steps, the purification method of the present invention includes, for example, a sterilization step of sterilizing soil or wastewater in which chlorine compounds have been decomposed by heating or ultraviolet irradiation, the number of microorganisms in the contaminant, the substrate Other steps such as a sampling step for measuring the concentration or the like may be included.
[0037]
In the purification method of the present invention, in the dechlorination step and the compound decomposition step in the second purification method, the above-mentioned adsorbent, for example, another adsorption having a pore size distribution suitable for physical adsorption of the above-mentioned compound. A material may be used, and the gas contactor described above may be used in the compound decomposition step in the second purification method.
[0038]
The present invention provides the following purification device as a preferred configuration for realizing the first and second purification methods described above.
That is, the present invention provides, as a preferred configuration for realizing the first purification method, a contaminant purification apparatus for decomposing and purifying contaminants containing chlorine compounds by microorganisms, and decomposing chlorine compounds in the contaminants. A decomposition reaction tank that decomposes the pollutant by containing at least an adsorbing component that physically adsorbs microorganisms, contaminants, and contaminants, temperature adjusting means that adjusts the temperature in the decomposition reaction tank, and contamination in the decomposition reaction tank The microorganism provides a purification device for contaminants (hereinafter also referred to as “first purification device”) which is a microorganism having an optimum temperature of at least 60 ° C. or more. The purification device will be described below.
[0039]
<First purification device>
Since the first purification device has a decomposition reaction tank and a temperature adjusting means, it forms a system in which the temperature is adjusted, and has a fluidizing means, so that the contaminants in the presence of microorganisms and adsorbing components are removed. It becomes possible to flow in the tank. As a result, the chlorine compound can be decomposed at the optimum temperature, the adsorption of the chlorine compound to the adsorbing component and the implantation of the microorganism on the adsorbing component are promoted, and an efficient microbial decomposition reaction is performed.
[0040]
The first purification device further includes an oxygen supply means for supplying oxygen into the decomposition reaction tank, and the microorganism is an aerobic microorganism having an optimum temperature of 65 ° C. or higher, which is a favorable condition for the microbial decomposition reaction. This is preferable in realizing the configuration of the apparatus and the simplification of the purification operation.
[0041]
The first purification device further includes a gas contactor that forms a passage that enhances the contact between the fluid and the gas, and the flow means is a means for causing the contaminant to flow at least in the passage of the gas contactor. In the case of using an aerobic microorganism, it is preferable to increase the oxygen concentration in the system.
[0042]
The first purification device as described above can take various preferred forms depending on the form of the contaminant to be purified. For example, when the pollutant is contaminated soil, a rotating shaft provided in the horizontal direction in the tank, a cylindrical body provided orthogonal to the rotating shaft, and fluid soil and gas in the cylindrical belt The structure which has the solid-gas contactor which forms the channel | path which improves contact property with is mentioned, Furthermore, various suitable forms can be taken with the form of these structures.
[0043]
More specifically, as the first purification device when the pollutant is contaminated soil, the cylindrical body having both ends opened is used, and the contaminated soil to the cylindrical body is separated from the decomposition reaction tank. The flow means is provided at least in a horizontal direction in the decomposition reaction tank and a rotation axis provided at right angles to the rotation axis and accompanying the rotation of the rotation axis. The structure which is a cylindrical body which scoops the contaminated soil in a tank with an edge part, and the said gas contactor is a solid-gas contactor which forms the said channel | path in a cylindrical body is mentioned.
[0044]
In addition, as the first purification device when the contaminated material is contaminated soil, there is a configuration in which the cylindrical body that is closed at both ends is used, and the contaminated soil is caused to flow in the cylindrical body. A rotation shaft provided at least in the horizontal direction, and the decomposition reaction tank is provided perpendicular to the rotation shaft, closed at the end and accommodates contaminated soil inside (for example, a configuration in which the end can be opened and closed, etc.) And a configuration in which the gas contactor is a solid-gas contactor that forms the passage in the cylindrical body.
[0045]
As described above, in the present invention, it is preferable to use an adsorbent that physically adsorbs the chlorine compound from the viewpoint of improving the contact between the chlorine compound and the microorganism, but in the case where the contaminant is contaminated soil, such adsorption is performed. The material is preferably in a form that flows together with the contaminated soil, for example, a particulate adsorbent, and more preferably a particulate adsorbent that is added to the contaminated soil with microorganisms on the surface.
[0046]
When the contaminant is contaminated water, as the first purification device, the flow means is connected to an oxygen supply means, and bubbles are generated from the bottom of the decomposition reaction tank toward the passage of the gas contactor. The gas contactor is a gas-liquid contactor that forms the passage in the contaminated water, and the adsorbent is fixed in the decomposition reaction tank and passes through the flow of the contaminated water from the gas-liquid contactor. The structure which is an adsorbent of these.
[0047]
In the first purification apparatus, the adsorbent is a zeolite having pores having a pore size distribution equivalent to 1 or more times the molecular size of the chlorine compound. More specifically, natural zeolite having pores having a pore size distribution corresponding to 3 to 5 times the molecular size of the chlorine compound is preferable.
[0048]
The said decomposition reaction tank is a thing according to the form and physical property of a contaminant, the form of an adsorbent, etc., the optimal temperature of the microbe accommodated, the optimal environment (anaerobic environment or aerobic environment) of the microbe accommodated. Etc.) as long as the optimum conditions in the microbial degradation reaction can be realized. Examples of such a decomposition reaction tank include an airtight reaction tank and a rotary reaction tank.
[0049]
The temperature adjusting means is not particularly limited as long as it can arbitrarily adjust the temperature in the decomposition reaction tank and can realize the optimum temperature of the microorganisms contained in the decomposition reaction tank. Examples of such temperature adjusting means include a heating medium such as hot water and steam, a jacket having a refrigerant passage such as cold water on the outer peripheral surface of the decomposition reaction tank, a heater provided in the tank, hot water and hot water in the tank. Examples include heating means for supplying a heat medium such as wind and steam, and various conventionally known configurations can be suitably used.
[0050]
The flow means is not particularly limited as long as it is a means for causing contaminants to flow in a predetermined direction in the entire decomposition reaction tank or in a partial area. Such a flow means is preferably selected according to the form of the contaminant. For example, in the case where the contaminant is in a liquid state, a nozzle that forms a flow of the contaminant in a predetermined direction can be used. For example, in the case where the contaminant is a solid such as soil, the contamination in the tank is caused by the rotation axis provided in the horizontal direction in the decomposition reaction tank and the rotation axis provided perpendicular to the rotation axis. A fluid passage that is open at both ends is formed by a peripheral wall, such as a cylindrical body that scoops the soil at the end, and a structure that can supply contaminants to the fluid passage and can be freely tilted, and the end is blocked and contaminated. The structure etc. which can incline the cylindrical body which can accommodate soil freely are mentioned. The cross-sectional shape of the cylindrical body is not limited to a circular shape, and may be various shapes such as a non-circular shape, a rectangular shape, and a polygonal shape.
[0051]
The adsorbent can be accommodated in the decomposition reaction tank in various forms according to the physical properties of the adsorbing component and the form of contaminants. The form of the adsorbent may be a form in which contaminants flow and pass through the adsorbent, or a form in which the adsorbent flows together with the contaminants. As a form in which the contaminants flow and pass through the adsorbent, for example, spherical adsorbents having at least an adsorbing component on the surface are fixed to each other (for example, adhesion or sintering), and the gap between the adsorbents is passed through the contaminant path. And an adsorbent in which adsorbent particles are supported on the surface of a support such as a honeycomb structure formed of ceramic paper. Examples of the form in which the adsorbent flows together with contaminants include particulate adsorbents such as granules and powders.
[0052]
The oxygen supply means is not particularly limited as long as it can supply oxygen into the decomposition reaction tank. Such an oxygen supply means may be a means for supplying only oxygen into the decomposition reaction tank, or a means for supplying a gas containing oxygen such as air into the decomposition reaction tank. Examples of means for supplying only oxygen to the decomposition reaction tank include an oxygen cylinder connected to the inside of the decomposition reaction tank by an air passage. Examples of means for supplying a gas containing oxygen to the decomposition reaction tank include air blowing means such as a compressor connected to the inside of the decomposition reaction tank through an air passage. The oxygen supply means is preferably a means for supplying oxygen or a gas containing oxygen directly into the decomposition reaction tank from the viewpoint of improving the contact with contaminants.
[0053]
The said gas contactor will not be specifically limited if it is a means to enlarge the contact area and contact time of a fluid (contaminant) and gas (oxygen, air, etc.). A configuration for increasing the contact area between the contaminant and the gas includes a configuration for miniaturizing either the contaminant or the gas (bubble), and a configuration for increasing the contact time between the contaminant and the gas. As an example, the structure which delays the flow of the refined | contaminated contaminant or gas is mentioned, It is more preferable that the gas contactor used for this invention has both of these.
[0054]
Examples of the structure for miniaturizing the contaminant include a member provided so as to extend in a direction crossing the flow direction of the contaminant in the flow path of the contaminant. For example, the member is provided along the cross section of the flow path of the contaminant. Examples include a lattice-like member, a net-like member, and a structure in which these members are provided in a plurality of stages along the flow direction. As a configuration for making the bubbles fine, bubble generating means such as a gas outlet having a plurality of pores may be mentioned.
[0055]
Examples of the structure for delaying the flow of the refined contaminant or gas include a member provided so as to extend obliquely with respect to the flow direction of the contaminant in the flow path of the contaminant. A member such as the lattice member, mesh member and baffle plate provided obliquely with respect to the direction, a structure in which these members are provided in a plurality of stages along the flow direction, and a structure in which the wall surface of the flow passage is an inclined surface with respect to the flow direction Etc.
[0056]
As a specific example of the gas contactor, a filler for a cooling tower can be exemplified. In the first purification device, the contact property between contaminants and gas can be obtained by using a gas contactor having one or more of the above-described configurations. This is even more preferable in that sufficient oxygen is supplied to microorganisms that decompose chlorine compounds in pollutants and suitable conditions for the microbial decomposition reaction are adjusted.
[0057]
The exhaust gas treatment means is not particularly limited as long as it is a means capable of detoxifying the gas generated by the microbial decomposition reaction, and an appropriate means is selected according to the chlorine compound, other substances contained in the contaminants, and the like. It is preferable to do. As a method for removing harmful components in the exhaust gas from the exhaust gas, known methods such as aggregation, dissolution, adsorption, and combustion can be used.
[0058]
As such exhaust gas treatment means, for example, a condenser (cooler) for cooling the exhaust gas, a gas-liquid separator (for example, an alkali trap) for separating a predetermined component in the exhaust gas, a predetermined component in the exhaust gas is adsorbed A configuration having an adsorber filled with an adsorbent (for example, activated carbon or the like) can be given.
[0059]
The heat pump is not particularly limited as long as it is a means capable of simultaneously generating a heat medium and a refrigerant, but water is generally used as the medium. The use of the heat medium and the refrigerant generated by the heat pump is not particularly limited, but it is preferable that the heat medium is mainly used for adjusting the temperature of the decomposition reaction tank, and the refrigerant is mainly used for the cooling liquid of the condenser. An example of such a heat pump is a heat pump that uses carbon dioxide gas as a refrigerant for a pump and simultaneously generates 90 ° C. hot water and 14 ° C. or lower cold water.
[0060]
In the first purification device, a part of the gas generated in the decomposition reaction tank may be returned to the decomposition reaction tank. As such a configuration, for example, a return air passage for connecting the decomposition reaction tank and the passage of the oxygen supply means can be cited. Such a configuration is preferable in maintaining the gas conditions in the microbial decomposition reaction system.
[0061]
In the first purification apparatus, from the viewpoint of monitoring the progress of the microbial decomposition reaction and maintaining suitable conditions, temperature detection means for detecting the temperature of the contaminant in the decomposition reaction tank, and pH for detecting the pH of the contaminant. Various detection means such as detection means and oxygen concentration detection means for detecting the dissolved oxygen concentration in the contaminant may be provided according to the form of the contaminant. In the first purification device, it is possible to purify contaminants by anaerobic microorganisms by using oxygen removing means in the second purification device described later.
[0062]
The present invention provides, as a preferred configuration for realizing the second purification method, a contaminant purification apparatus for decomposing and purifying contaminants containing chlorine compounds with microorganisms, and for decomposing chlorine compounds in the contaminants. Dechlorination stirring tank that contains at least dechlorination microorganisms and contaminants and removes chlorine from the contaminants, dechlorination temperature adjustment means that adjusts the temperature in the dechlorination stirring tank, and chlorine is removed Compound decomposition microorganisms that decompose compounds in pollutants, compound decomposition agitation tanks that contain at least contaminants from which chlorine has been removed and decompose the compounds, and compound decompositions that adjust the temperature in the compound decomposition agitation tanks The dechlorination microorganism is a dechlorination microorganism having an optimum temperature of 60 ° C. or higher, and the compound degrading microorganism is a compound degrading microorganism having an optimum temperature of 65 ° C. or higher. Purification of things Location to provide (hereinafter, also referred to as "second purifying apparatus").
[0063]
<Second purification device>
Since the second purification device has a dechlorination stirring tank and a dechlorination temperature adjusting means, the dechlorination step can be performed under a desired temperature condition. In addition, since the second purification apparatus has a compound decomposition stirring tank and a compound decomposition temperature adjusting means, the compound decomposition step can be performed under desired temperature conditions, and the optimum temperature of the microorganism to be used can be achieved. It is possible to perform a corresponding dechlorination step and a compound decomposition step.
[0064]
Further, the second purification device is a means for realizing a dechlorination step using an anaerobic microorganism and a compound decomposition step using an aerobic microorganism, and the dechlorination microorganism is an anaerobic microorganism, and the compound decomposition The microorganism for aerobic is preferably an aerobic microorganism, and preferably has an oxygen removing means for removing oxygen in the dechlorination stirring tank and a compound decomposition oxygen supplying means for supplying oxygen into the compound decomposition stirring tank.
[0065]
According to the said structure, since a dechlorination process can be performed on the desired temperature conditions from which oxygen is removed, it becomes possible to implement | achieve the dechlorination process using an anaerobic microorganism suitably. Moreover, according to the said structure, since a compound decomposition process can be performed on the desired temperature conditions by which oxygen is fully supplied, it becomes possible to implement | achieve the compound decomposition process using an aerobic microorganism suitably. .
[0066]
Moreover, it is preferable that said 2nd purification apparatus has a dechlorination exhaust gas treatment means which processes the gas discharged | emitted from the dechlorination stirring tank as a means for implement | achieving the said dechlorination exhaust gas treatment process. According to such a configuration, it becomes possible to prevent environmental influences caused by harmful gases such as chlorine gas generated in the dechlorination step.
[0067]
Further, the second purification device comprises a dechlorination temperature detection means for detecting the temperature in the dechlorination stirring tank, and a dechlorination oxygen concentration detection means for detecting the oxygen concentration in the dechlorination stirring tank. It is preferable to have a dechlorination reaction in the dechlorination step, to trace suitable dechlorination reaction conditions, and to reproduce a suitable dechlorination reaction.
[0068]
In addition, when the contaminant is contaminated water, the second purification device may further include a dechlorination pH detection means for detecting the pH in the dechlorination stirring tank, which is a suitable reaction for the dechlorination reaction. It is more preferable to confirm the conditions and reproduce a suitable dechlorination reaction.
[0069]
Further, the second purification device comprises a compound decomposition temperature detecting means for detecting the temperature in the compound decomposition stirring tank, and a compound decomposition oxygen concentration detecting means for detecting the oxygen concentration in the compound decomposition stirring tank. It is preferable to have a decomposition reaction in the compound decomposition step, to confirm suitable reaction conditions for the compound decomposition reaction, and to reproduce a suitable compound decomposition reaction.
[0070]
In addition, when the contaminant is contaminated water, the second purification device preferably has a compound decomposition pH detecting means for detecting the pH in the compound decomposition stirring tank. It is more preferable to confirm the above and reproduce a suitable compound decomposition reaction.
Hereinafter, the second purification device will be described in more detail.
[0071]
The agitation tank for dechlorination may be a reaction tank that contains a contaminant and a microorganism for dechlorination and has a stirring means for agitating them so that a suitable reaction is performed. What is necessary is just to use the thing of a suitable structure according to the kind of microorganisms etc. which are used for a dechlorination process, and when a dechlorination process is performed using an anaerobic microorganism under the conditions from which oxygen was removed, What has airtightness is preferable.
[0072]
Further, the stirring means in the dechlorination stirring tank may be any means that can sufficiently stir the contaminant and the dechlorination microorganism. It is preferable to select an appropriate stirring means depending on the form of the contaminant. Examples of the stirring means include those having stirring blades such as a paddle type, a turbine type, and a propeller type. Depending on the form of contaminants, mixing of solid materials, stirring of liquid, stirring of slurry, gas-liquid What is necessary is just to select the stirring means suitable for stirring objects, such as stirring. Note that the above-described flow means may be used as the stirring means.
[0073]
The compound decomposition agitation tank can also have the same configuration as the dechlorination agitation tank, and an appropriate one may be used depending on the type of microorganism used in the compound decomposition step, the form of contaminants, and the like.
[0074]
The temperature adjusting means for dechlorination is not particularly limited as long as the temperature in the stirring tank for dechlorination can be adjusted to the optimum temperature of the microorganism for dechlorination to be used, and the temperature adjusting means in the first purification apparatus is not limited. Can be used. Also, the temperature adjusting means for compound decomposition is not particularly limited as long as the temperature in the stirring tank for compound decomposition can be adjusted to the optimum temperature of the microorganism for compound decomposition to be used, and the temperature adjusting means in the first purification device. Can be used.
[0075]
The oxygen removing means may be any means that can remove oxygen in the stirring tank. For such oxygen removing means, various conventionally known means can be used. For example, a depressurizing means such as a vacuum pump for depressurizing the inside of the tank, or an oxygen scavenger such as iron oxide is put into the tank. An oxygen scavenger charging means such as a hopper, a gas introducing means for replacing the atmosphere in the tank with an inert gas such as nitrogen gas or argon, etc. can be exemplified, and these are used alone or in combination of two or more. be able to.
[0076]
The compound decomposing oxygen supply means may be any means that can supply oxygen into the stirring tank. Such an oxygen supply means for decomposing compounds may be a means for supplying only oxygen, such as connecting an oxygen cylinder and a stirring tank, like the oxygen supplying means described above, or a compressor for sending air into the stirring tank, etc. The air blowing means may be used. Further, the compound decomposition oxygen supply means may also serve as a means for assisting in the agitation of contaminants, and such a compound decomposition oxygen supply means has an oxygen outlet opening near the bottom of the stirring tank. Means can be exemplified.
[0077]
In addition, when gas is supplied from the vicinity of the bottom of the tank, such as purging nitrogen gas in the oxygen removing means or oxygen supplying means for decomposing compounds, it can be used to stir contaminants. It is preferable for making the atmosphere more uniform.
[0078]
The dechlorination exhaust gas treatment means may be any means capable of detoxifying the exhaust gas discharged from the dechlorination stirring tank, and an appropriate one may be used depending on the type of gas discharged. As such a dechlorination exhaust gas treatment means, for example, the same configuration as the above-described exhaust gas treatment means can be used, and the adsorbent or the like may be appropriately selected depending on the type of gas to be discharged.
[0079]
The dechlorination temperature detection means is not particularly limited as long as it is a means for detecting the temperature in the dechlorination stirring tank, that is, the system in which the dechlorination by the microbial reaction is performed, and a known means may be used. However, it is preferable to select an appropriate one depending on the form of the contaminant. Further, the compound decomposition temperature detection means may be any means for detecting the temperature in the compound decomposition stirring tank, that is, the temperature in the system where the compound decomposition by the microbial reaction is performed, and is similar to the dechlorination temperature detection means. A configuration can be used.
[0080]
In the present invention, the temperature detecting means is preferably provided in the tank. However, the temperature detecting means may not necessarily be provided in the tank. For example, when the contaminant is a solid matter such as contaminated soil, the temperature fluctuation of the exhaust gas May be provided at an arbitrary position downstream of the inside of the tank as long as it is upstream of a component (for example, a cooler for exhaust gas treatment).
[0081]
The oxygen concentration detecting means for dechlorination is not particularly limited as long as it is a means for detecting the oxygen concentration in the stirring tank for dechlorination. Here, in the present invention, the oxygen concentration in the tank refers to the oxygen concentration in the system. In the case where the contaminant is a solid substance such as soil, the oxygen concentration in the tank refers to the oxygen concentration in the tank, and the contaminant is a liquid such as sewage. Then, it refers to the dissolved oxygen concentration in the pollutant. Therefore, it is preferable to select an appropriate means for the dechlorination oxygen concentration detection means depending on the form of the contaminant. The compound decomposition oxygen concentration detection means may be any means for detecting the oxygen concentration in the compound decomposition stirring tank, and the same configuration as the dechlorination oxygen concentration detection means can be used.
[0082]
In the present invention, the oxygen concentration detecting means is preferably provided in the tank, but not necessarily provided in the tank. For example, when the contaminant is a solid matter such as contaminated soil, It may be provided at an arbitrary position downstream of the inside of the tank as long as it is upstream of a component that fluctuates in oxygen concentration (for example, an adsorber that adsorbs a predetermined component in the exhaust gas).
[0083]
The pH detecting means for dechlorination is not particularly limited as long as it is a means for detecting the pH in the stirring tank for dechlorination, preferably used when the contaminant is in a liquid state such as sewage. Known means such as a sensor can be used. Further, the compound decomposing pH detecting means may be any means for detecting the pH in the compound decomposing stirring tank, and the same configuration as the dechlorinating pH detecting means can be used.
[0084]
In the second purification apparatus, it is preferable that the dechlorination stirring tank and the compound decomposition stirring tank are provided independently in order to perform the purification operation continuously and efficiently. From the viewpoint of conversion, an integrated stirring tank can be used as a dechlorination stirring tank and a compound decomposition stirring tank. Further, the same or similar adsorbent as in the first purification device described above may be accommodated in the stirring tank in the second purification device.
[0085]
In addition to the above-described means, the purification apparatus of the present invention described above includes a conveying means for conveying contaminants from the decomposition reaction tank to the next stage, or from the dechlorination stirring tank to the compound decomposition stirring tank, It is preferable to appropriately provide a sterilizing means for sterilizing the contaminants purified by the decomposition, a pressure detecting means for detecting the pressure in the decomposition reaction tank or the stirring tank, and the like.
[0086]
Examples of the conveyance means include solid conveyance means such as a screw conveyor when the contaminant is a solid substance such as soil, and liquid conveyance means such as a pump when the contamination is a liquid such as sewage. As for sterilization means, for example, sterilization means by ozone injection, sterilization means by injection of a bactericide such as sodium hypochlorite solution, means for sterilizing contaminants by heating, drying, irradiation with ultraviolet rays or the like may be used. Examples of suitable means include a microwave heat sterilization drying apparatus. About a pressure detection means, it is preferable to select the thing of a suitable material with the atmosphere in a system, and well-known means, such as a Bourdon tube pressure gauge, can be illustrated.
[0087]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below. First, using the second purification device described above as the purification device, using anaerobic microorganisms as dechlorination microorganisms, using aerobic microorganisms as compound decomposition microorganisms, and contamination containing chlorine compounds such as dioxins as contaminants An embodiment of the present invention for purifying soil will be described.
[0088]
<First Embodiment>
As shown in FIG. 1, the purification apparatus in the present embodiment includes a dechlorination stirring tank 1, a compound decomposition stirring tank 2, and a microwave heat sterilization drying apparatus 3. The dechlorination agitation tank 1 and the compound decomposition agitation tank 2 are connected by a screw type conveyor 4 as a conveying means, and are configured to convey contaminated soil from the dechlorination agitation tank 1 to the compound decomposition agitation tank 2. Has been. Further, the compound decomposition stirring tank 2 and the microwave heat sterilization drying apparatus 3 are connected by a screw type conveyor 5 and configured to convey soil from the compound decomposition stirring tank 2 to the microwave heat sterilization drying apparatus 3. ing.
[0089]
In the dechlorination stirring tank 1, temperature adjusting means 6 for adjusting the temperature in the tank, a solid phase stirring device 7 for stirring the contaminated soil in the tank, and the inside of the dechlorination stirring tank 1 are replaced with nitrogen. Nitrogen supply means 8 for the above, dechlorination exhaust gas treatment means 9 for treating the gas discharged from the dechlorination stirring tank 1, temperature detection means 10 for detecting the temperature in the tank, and oxygen in the tank Oxygen concentration detection means 11 for detecting the concentration is provided.
[0090]
Air is introduced into the compound decomposition stirring tank 2, temperature adjusting means 6 for adjusting the temperature in the tank, a solid phase stirring device 7 for stirring the contaminated soil in the tank, and the compound decomposition stirring tank 2. Air supply means 14 for processing, compound decomposition exhaust gas treatment means 15 for processing gas discharged from the compound decomposition stirring tank 2, temperature detection means 10 for detecting the temperature in the tank, and oxygen in the tank Oxygen concentration detection means 11 for detecting the concentration is provided.
[0091]
The dechlorination stirring tank 1 and the compound decomposition stirring tank 2 are both airtight and can be sealed. Since the agitation tank 1 for dechlorination uses anaerobic microorganisms as dechlorination microorganisms, it has an airtight structure in order to maintain the atmosphere in the system and prevent the inflow of oxygen into the system. In addition, since the compound decomposition agitation tank 2 uses aerobic microorganisms as compound decomposition microorganisms, even if air flows in from the outside, the oxygen concentration in the system is kept constant. From a preferable viewpoint, the structure is airtight.
[0092]
The microwave heat sterilization drying apparatus 3 is a means for sterilizing the microorganisms for decomposing compounds in the treated soil. Therefore, the device is not limited to the above device as long as it can sterilize the compound-decomposing microorganism.
[0093]
The temperature adjusting means 6 is a jacket provided on the outer periphery of the dechlorination stirring tank or the compound decomposition stirring tank, and is a means for heating the contaminated soil in the stirring tank through warm water or steam.
[0094]
The nitrogen supply means 8 is one of oxygen removing means for removing oxygen in the dechlorination stirring tank 1, and is connected to the nitrogen cylinder 8a and the bottom of the dechlorination stirring tank 1 connected to the nitrogen cylinder 8a. It has a nitrogen supply pipe 8b that opens and an ejector 8c that is interposed between the nitrogen cylinder 8a and the nitrogen supply pipe 8b.
[0095]
The dechlorination exhaust gas treatment means 9 is a means for treating and detoxifying the gas discharged from the dechlorination stirring tank 1, and includes a compressor 9a, a cooler (condenser) 9b for cooling the exhaust gas, A gas-liquid separator 9c for separating the exhaust gas component into liquid and gas, an adsorber 9d filled with a dechlorinating agent or dechlorinating member (for example, an alkali agent-attached filter), and a humidifier for humidifying the processing gas 9e. The humidifier 9e and the ejector 8c are connected, and the humidified processing gas is supplied to the dechlorination stirring tank 1.
[0096]
The humidifier 9e is a humidifying means for keeping the system at a predetermined humidity because an anaerobic microorganism is used as the dechlorination microorganism and the anaerobic microorganism prefers a humid environment. Any humidifying means capable of maintaining the above humidity can be used without limitation, and various conventionally known humidifying means can be used.
[0097]
The temperature detecting means 10 is a thermometer for detecting the temperature of the contaminated soil accommodated in the dechlorination stirring tank 1 and the temperature of the contaminated soil accommodated in the compound decomposition stirring tank 2.
[0098]
The oxygen concentration detection means 11 is an oxygen sensor for detecting the oxygen concentration in the dechlorination stirring tank 1 and the oxygen concentration in the compound decomposition stirring tank 2.
[0099]
The air supply means 14 is a compound decomposition oxygen supply means for supplying oxygen into the compound decomposition agitation tank 2, and is connected to the air supply source 14a and the air supply source 14a. It has an air supply pipe 14b that opens to the bottom, and a compressor 14c that is interposed between the air supply source 14a and the air supply pipe 14b. The air supply source 14a may be a cylinder filled with air (oxygen) or may be an air intake port for taking in air (oxygen) from the atmosphere.
[0100]
The compound decomposition exhaust gas treatment means 15 is a means for treating the gas discharged from the compound decomposition agitation tank 2. The compound decomposition exhaust gas treatment means 15 is connected to the compound decomposition agitation tank 2 and treats or discharges the exhaust gas as necessary. The exhaust path from the compound decomposition exhaust gas treatment means 15 is connected to the upstream side of the compressor 14c of the air supply means 14, and a part of the exhaust gas is supplied to the compound decomposition agitation tank 2. .
[0101]
Next, an embodiment of the purification method of the present invention (the second purification method) for purifying contaminated soil using the purification device in the present embodiment will be described.
First, the contaminated soil is put into the dechlorination stirring tank 1.
[0102]
When the contaminated soil is put into the dechlorination stirring tank 1, the temperature adjusting means 6 heats the dechlorination stirring tank 1 to the optimum temperature of the anaerobic microorganisms to be used, and the dechlorination stirring tank 1 is optimized. Maintain temperature. The temperature in the dechlorination stirring tank 1 is measured by the temperature detection means 10. The temperature in the tank is measured by the temperature detection means 10 from the start of heating to the end of the dechlorination reaction.
[0103]
When the inside of the dechlorination stirring tank 1 is maintained at an optimum temperature, an oxygen scavenger (for example, iron oxide) is introduced into the dechlorination stirring tank 1, and the solid phase stirring apparatus 7 is operated and stirred. Exclude oxygen in the tank. The oxygen concentration in the dechlorination stirring tank 1 is measured by the oxygen concentration detecting means 11. The measurement of the oxygen concentration in the tank by the oxygen concentration detection means 11 is performed from when the deoxygenating agent is introduced into the tank until the completion of the dechlorination reaction. In addition, when heat_generation | fever is accompanied by injection | throwing-in of an oxygen scavenger, the temperature adjustment in a tank is performed by suppressing the temperature increase heating amount of the temperature adjustment means 6. FIG.
[0104]
Deoxygenation may be performed by depressurizing the dechlorination stirring tank 1. In such a case, deoxygenation is performed by a decompression means such as a vacuum pump (not shown). This decompression means may be directly connected to the dechlorination stirring tank 1 or may be incorporated in the dechlorination exhaust gas treatment means 9. In this case, the agitation tank needs to be airtight.
[0105]
After deoxygenation, nitrogen is supplied from the nitrogen supply means 8 into the dechlorination stirring tank 1, and the tank is purged with nitrogen to replace the inside with a nitrogen atmosphere. At this time, nitrogen is supplied so that the pressure in the tank is slightly increased compared to the outside air. Nitrogen is supplied until the dechlorination reaction is completed, and the inside of the system is maintained in an oxygen-free atmosphere.
[0106]
The pressure in the dechlorination stirring tank 1 is measured by a pressure gauge (not shown) provided in the dechlorination stirring tank 1. This pressure measurement is performed to confirm the prevention of air from entering the tank. The pressure in the tank is measured with this pressure gauge from the start of nitrogen supply to the end of the dechlorination reaction.
[0107]
When the temperature and oxygen concentration are adjusted to desired conditions, an anaerobic microorganism (for example, Clostridium pastorianum, optimum temperature: 60 ° C.) is put into the dechlorination stirring tank 1 together with a medium (for example, sawdust and acetic acid). The dechlorination reaction of contaminated soil starts by the input of anaerobic microorganisms.
[0108]
Accompanying the dechlorination reaction, gases such as nitrogen gas, water vapor component, chlorine gas and methane gas are generated in the dechlorination stirring tank 1. These gases are processed by the dechlorination exhaust gas processing means 9. If an example of the exhaust gas treatment is given, the water vapor component is cooled by the cooler 9b, and the condensed gas and the predetermined gas component absorbed by the liquid stored in the gas-liquid separator 9c are separated by the gas-liquid separator 9c. Is done. Chlorine gas is adsorbed by the dechlorinating agent by the adsorber 9d. Although methane gas can be absorbed by amines, a treatment means for methane gas is not particularly provided in this embodiment.
[0109]
The processing gas is humidified by the humidifying device 9e and supplied to the nitrogen supply means 8 from the ejector 8c. In this way, the exhaust gas from the dechlorination step is treated and returned to the system again. The nitrogen gas lost in the reuse cycle is replenished from the nitrogen cylinder 8a.
[0110]
Sampling the contaminated soil in the dechlorination agitation tank 1 as necessary, such as every predetermined time, measuring the number concentration and substrate concentration (chlorine compound concentration) of dechlorination microorganisms in the sample soil, and determining the substrate degradation rate To analyze.
[0111]
When the completion of the dechlorination reaction of the contaminated soil is confirmed, the screw conveyor 4 is operated, and the dechlorinated contaminated soil is conveyed from the dechlorination stirring tank 1 to the compound decomposition stirring tank 2. When the transport of the soil to the compound decomposition agitation tank 2 is completed, it is confirmed that the dechlorination agitation tank 1 is empty, the new contaminated soil is put into the dechlorination agitation tank 1, and the above operation is performed. repeat.
[0112]
When the contaminated soil is conveyed to the compound decomposition agitation tank 2, the inside of the compound decomposition agitation tank 2 is heated to the optimum temperature of the aerobic microorganism to be used by the temperature adjusting means 6, and the inside of the compound decomposition agitation tank 2 is Maintain at the proper temperature. The temperature in the compound decomposition stirring tank 2 is measured by the temperature detecting means 10. The temperature in the tank is measured by the temperature detection means 10 from the start of heating to the end of the decomposition reaction.
[0113]
When the inside of the compound decomposition stirring tank 2 is maintained at the optimum temperature, stirring is started, and air is injected into the compound decomposition stirring tank 2 by the air supply means 14 to maintain the oxygen concentration in the tank at the atmospheric pressure component value. . The oxygen concentration in the compound decomposition stirring tank 2 is measured by the oxygen concentration detecting means 11. The oxygen concentration measurement in the tank by the oxygen concentration detection means 11 is performed from the press-fitting of air to the end of the decomposition reaction.
[0114]
The pressure in the compound decomposition stirring tank 2 is measured by a pressure gauge (not shown) provided in the compound decomposition stirring tank 2. The pressure measurement in the tank with this pressure gauge is different from that in the dechlorination stirring tank, but there is no significance in preventing atmospheric intrusion, but it is performed to confirm the oxygen concentration in the tank. Is done.
[0115]
Once the optimum temperature has been established and the oxygen concentration has reached the atmospheric pressure component concentration, aerobic microorganisms (eg Midosuji, optimum temperature: 65 ° C) and medium (eg sawdust or rice bran) are used for compound degradation. Charge to stirring tank 2. The decomposition reaction of the compound in the contaminated soil is started by the input of aerobic microorganisms.
[0116]
Along with the decomposition reaction, gases such as air and water vapor components are generated in the compound decomposition stirring tank 2. These gases are treated by an exhaust gas treatment means 15 for compound decomposition (for example, an adsorber filled with activated carbon as an adsorbent), a part thereof is discharged into the atmosphere, and most of the treated gas is sent to the air supply means 14. Return to air.
[0117]
Sampling the contaminated soil in the compound decomposition agitation tank 2 as necessary, such as every predetermined time, and measuring the number concentration and substrate concentration of the compound decomposition microorganism in the sample soil (the compound concentration), the substrate decomposition rate To analyze.
[0118]
After confirming the predetermined decomposition rate, the screw type conveyor 5 is operated, and the treated soil is conveyed from the compound decomposition stirring tank 2 to the microwave heat sterilization drying device 3 to be sterilized and dried, and discharged as purified treated soil. .
The above operation is repeated to continuously purify the contaminated soil.
[0119]
Since the purification apparatus in the present embodiment uses an anaerobic microorganism having an optimum temperature of 60 ° C. as the dechlorination microorganism and an aerobic microorganism having an optimum temperature of 65 ° C. as the compound decomposition microorganism, The purification speed of the contaminated soil containing the compound is further improved, and industrial purification of the contaminated soil is possible. In addition, since microorganisms with a higher optimum temperature than normal bacteria are used, the effects of various bacteria are eliminated, microbial reactions can be more easily purified, and highly reproducible contaminated soil can be purified. is there.
[0120]
Moreover, since the purification apparatus in the present embodiment has a configuration in which the dechlorination stirring tank 1 and the compound decomposition stirring tank 2 are connected in series, the dechlorination reaction and the decomposition reaction can be performed at the same time. Therefore, the contaminated soil can be purified efficiently.
[0121]
Further, the purification apparatus in the present embodiment uses an anaerobic microorganism as the dechlorination microorganism, uses an aerobic microorganism as the compound decomposition microorganism, and performs the dechlorination step before the compound decomposition step. Inactivation of microorganisms for compound degradation by chlorine compounds can be suppressed, and microbial reactions in each process can be purified without providing a sterilization process between the processes. Efficient purification of contaminated soil with simpler processes and configurations It can be performed.
[0122]
In the dechlorination step, the purification apparatus according to the present embodiment forms a system in which oxygen is mainly removed by nitrogen purge. At that time, the system is maintained in a pressurized state by supplying nitrogen gas. Therefore, inflow of air from the outside is prevented, and an environment suitable for the activity of anaerobic microorganisms can be more reliably formed.
[0123]
In addition, since the purification apparatus in the present embodiment is configured to return the processing gas to the nitrogen supply means 8 and the air supply means 14 in the dechlorination and compound decomposition exhaust gas treatment means 9 and 15, respectively, The influence on the environment due to the discharge can be further reduced, and an environment suitable for the activity of microorganisms can be stably formed as compared with the case where the exhaust gas is not reused.
[0124]
Moreover, since the purification apparatus in the present embodiment is configured to humidify the processing gas and return the nitrogen gas to the nitrogen supply means 8 in the exhaust gas treatment step in the dechlorination step, the humidity adjustment in the dechlorination stirring tank 1 is performed. Therefore, an environment suitable for the activity of anaerobic microorganisms used as dechlorination microorganisms can be formed and maintained. In addition, the structure of this embodiment which humidifies the supplied nitrogen gas is much more effective in performing uniform humidity adjustment of contaminated soil.
[0125]
In addition, since the purification device in the present embodiment is configured to supply gas from the bottom of each tank in the dechlorination step and the compound decomposition step, the agitation efficiency of the contaminated soil is further improved, and it is suitable for the inside of the tank. It is effective to maintain a more uniform atmosphere.
[0126]
Further, in the purification method of the present embodiment, it is possible to accumulate data relating to the decomposition of the substrate by microorganisms from the sample soil data sampled in the dechlorination step and the compound decomposition step. The mechanism of decomposition can be elucidated. Moreover, the reproducibility of the suitable purification | cleaning of contaminated soil can be improved further by utilizing this.
[0127]
<Second Embodiment>
In the present embodiment, the second purification device described above is used as the purification device, an anaerobic microorganism is used as a dechlorination microorganism, an aerobic microorganism is used as a compound decomposition microorganism, and chlorine compounds such as dioxins are used as contaminants. One embodiment of the present invention for purifying contaminated water containing water will be described.
[0128]
As shown in FIG. 2, the purification apparatus in the present embodiment is for dechlorination with a dechlorination stirring tank 21 having a liquid phase stirring apparatus 27 suitable for liquid stirring and a liquid phase stirring apparatus 27. And a stirring tank 22. Both stirring tanks are connected via a pump, and are configured to send contaminated water from the dechlorination stirring tank 21 to the compound decomposition stirring tank 22.
[0129]
The dechlorination agitation tank 21 is configured in the same manner as the dechlorination agitation tank in the first embodiment described above except that it has a pH detection means 23 and a dechlorination exhaust gas treatment means 29. The compound decomposition agitation tank 22 is also configured in the same manner as the compound decomposition agitation tank in the first embodiment described above except that it includes a pH detection means 23 and a compound decomposition exhaust gas treatment means 25. The oxygen concentration detection means 11 is provided so as to detect the dissolved oxygen concentration of the contaminated water in the tank.
[0130]
The pH detection means 23 is a pH sensor for detecting the pH of the contaminated water stored in the dechlorination stirring tank 21 and the contaminated water stored in the compound decomposition stirring tank 22.
[0131]
The dechlorination exhaust gas treatment means 29 does not have the compressor 9a and the humidifier 9e, and is configured to send the liquid separated by the gas-liquid separator 9c to the dechlorination stirring tank 21, as described above. The exhaust gas treatment means 9 for dechlorination in the first embodiment is configured in the same manner. The compound decomposition exhaust gas treatment means 25 includes a cooler 9b and a gas-liquid separator 9c, and is configured to send the liquid separated by the gas-liquid separator 9c to the compound decomposition stirring tank 22. Yes.
[0132]
Next, an embodiment of the purification method of the present invention (second purification method described above) that purifies contaminated water using the purification device of the present embodiment will be described.
First, contaminated water is put into the dechlorination stirring tank 21.
[0133]
When the contaminated water is put into the dechlorination stirring tank 21, the inside of the dechlorination stirring tank 21 is heated to the optimum temperature of the anaerobic microorganism to be used by the temperature adjusting means 6, and the inside of the dechlorination stirring tank 21 is optimized. Maintain temperature. The temperature in the dechlorination stirring tank 21 is measured by the temperature detection means 10 from the start of heating to the end of the reaction.
[0134]
Further, the pH of the contaminated water is measured by the pH detection means 23 from the start of heating to the end of the reaction. When the pH of the contaminated water is unsuitable for the activity of the dechlorination microorganism, the pH of the contaminated water may be adjusted with a known pH adjuster such as an acid, an alkali, or a buffer solution.
[0135]
When the inside of the dechlorination stirring tank 21 is maintained at an optimum temperature, an oxygen scavenger (for example, sodium sulfite aqueous solution) is introduced into the dechlorination stirring tank 21, and the liquid phase stirring apparatus 27 is operated to perform stirring. While excluding oxygen in the tank. The dissolved oxygen concentration in the contaminated water in the dechlorination stirring tank 21 is measured by the oxygen concentration detection means 11 from the introduction of the oxygen scavenger to the end of the reaction.
[0136]
After the optimum temperature is established and the decrease in dissolved oxygen concentration is confirmed, nitrogen gas is bubbled into the stirring tank, and the contaminated water is lifted and stirred by the difference in density between water and nitrogen gas. Nitrogen gas is supplied until the end of the reaction.
[0137]
In the case of treating contaminated water, it is preferable that the concentration of dissolved oxygen in the contaminated water be lowered. Therefore, it is preferable to perform deoxygenation in the system using an oxygen scavenger as described above rather than using a decompression means. Further, the inside of the agitation tank does not have to be in a pressurized state. However, in order to prevent oxygen from being sucked into the tank, it is preferable to supply nitrogen gas to the outside air so as to be slightly pressurized.
[0138]
When the temperature, dissolved oxygen concentration, and pH are adjusted to desired conditions, a medium (for example, an acetic acid aqueous solution) and an anaerobic microorganism (for example, Clostridium pastorianum, optimum temperature: 60 ° C.) are put into the dechlorination stirring tank 21. The dechlorination reaction of contaminated water starts by the input of anaerobic microorganisms.
[0139]
Nitrogen gas, solution mist, vapor components, chlorine gas, and other gases are generated from the dechlorination stirring tank 21 along with the dechlorination reaction. These gases are treated by the dechlorination exhaust gas treatment means 29. The exhaust gas is cooled by the cooler 9b, and vapor components and the like are separated into gas and liquid. The gas component that has been gas-liquid separated is dechlorinated by the adsorber 9 d, and the dechlorinated gas component is returned to the nitrogen supply means 8. Nitrogen gas is replenished from the nitrogen cylinder 8a for the portion lost in the series of cycles. The liquid component which has been subjected to gas-liquid separation is collected by the gas-liquid separator 9 c and sent to the dechlorination stirring tank 21.
[0140]
Sampling the contaminated water in the dechlorination agitation tank 21 as necessary at a predetermined time, etc., measuring the number concentration and substrate concentration (chlorine compound concentration) of the dechlorination microorganisms in the sample contaminated water, and determining the substrate degradation rate To analyze.
[0141]
When the completion of the dechlorination reaction of the contaminated water is confirmed, the pump is operated to feed the contaminated water from the dechlorination stirring tank 21 to the compound decomposition stirring tank 22. When the supply of contaminated water to the compound decomposition agitation tank 22 is completed, it is confirmed that the dechlorination agitation tank 21 is empty, and new contaminated water is added to the dechlorination agitation tank 21, Repeat the operation.
[0142]
When contaminated water is sent to the compound decomposition stirring tank 22, the temperature adjusting means 6 heats the inside of the compound decomposition stirring tank 22 to the optimum temperature of the aerobic microorganism to be used, and the inside of the compound decomposition stirring tank 22 is Maintain at optimum temperature. The temperature in the compound decomposition stirring tank 22 is measured by the temperature detection means 10 from the start of heating to the end of reaction. Moreover, the pH of the contaminated water in the compound decomposition stirring tank 22 is measured by the pH detecting means 23 until the reaction is completed.
[0143]
When the temperature in the compound decomposition agitation tank 22 is maintained at the optimum temperature, the agitation is started, and air is injected into the compound decomposition agitation tank 22 by the air supply means 14 to adjust the dissolved oxygen concentration of the contaminated water to the contaminated water. Saturate concentration according to temperature. The dissolved oxygen concentration of the contaminated water is measured by the oxygen concentration detection means 11 from the start of air supply to the end of the reaction.
[0144]
When the optimum temperature, pH, and dissolved oxygen concentration are confirmed, a medium (for example, tryptosoy) and an aerobic microorganism (for example, Midosuji, optimum temperature: 65 ° C.) are put into the compound decomposition stirring tank 22. The decomposition reaction of the compound in the contaminated water starts by the input of aerobic microorganisms.
[0145]
In the compound decomposition stirring tank 22, gases such as air, solution mist, and vapor components are generated in accordance with the decomposition reaction. These gases are processed by the compound decomposition exhaust gas processing means 25. The exhaust gas is cooled by the cooler 9b and separated into a liquid component, a soluble gas component, and a gas component by the gas-liquid separator 9b. The gas component is returned to the air supply means 14, and the liquid component containing the soluble gas component is supplied from the gas-liquid separator 9b to the compound decomposition stirring tank 22.
[0146]
The contaminated water in the compound decomposition agitation tank 22 is sampled as necessary, such as every predetermined time, and the substrate decomposition rate is analyzed from the number concentration of the compound decomposition microorganisms and the substrate concentration (the compound concentration) in the sample contaminated water.
[0147]
After confirming the predetermined decomposition rate, the treated water is discharged from the compound decomposition stirring tank 22.
The discharged treated water is discharged through a sterilization process, a cooling process, or the like as necessary when discharged directly into a river or the like. In the case of draining to a sewage treatment facility, it is not necessary to perform a sterilization process.
The above operation is repeated to purify contaminated water continuously.
[0148]
According to the present embodiment, similarly to the first embodiment, it is possible to suitably purify contaminated water that is a liquid contaminant.
[0149]
Moreover, in this Embodiment, since it was set as the structure which collect | recovers the liquid component in waste gas from the gas-liquid separator 9b to a stirring tank in an exhaust gas processing means, concentration of the contaminated water in a stirring tank is suppressed, and contaminated water is suppressed. Variations in each concentration can be further suppressed, and it is even more effective in maintaining conditions suitable for microbial activity.
[0150]
<Third Embodiment>
In the present embodiment, the first purification device described above is used as the purification device, an aerobic microorganism is used, and an embodiment of the present invention for purifying contaminated water containing chlorine compounds such as dioxins as contaminants. Will be described. In addition, about the structure similar to embodiment mentioned above, the same code | symbol is used and the description is abbreviate | omitted.
[0151]
As shown in FIG. 3, the purification apparatus according to the present embodiment includes a decomposition reaction tank 31, an air supply means 34 that is an oxygen supply means for supplying oxygen to the contaminated water stored in the decomposition reaction tank 31, and a decomposition reaction. An exhaust gas treatment means 35 for treating the gas discharged from the tank 31, a return air passage 33 for returning a part of the gas discharged from the decomposition reaction tank 31 to the air supply means 34, It has temperature detecting means 10 for detecting temperature, oxygen concentration detecting means 11 for detecting oxygen concentration in the tank, and pH detecting means 23 for detecting pH in the tank.
[0152]
The air supply means 34 has the same configuration as the air supply means 14 described above except that it has an ejector 8c in the air passage downstream of the compressor 14c and is connected to the bubble generating means 32 in the tank. Yes. Further, the exhaust gas treatment means 35 has the same configuration as the above-described dechlorination exhaust gas treatment means 29 except that it does not have a liquid supply path for returning the liquid in the gas-liquid separator 9c into the tank. The return air passage 33 has a condenser 9b in the passage, and is configured as an air passage connecting the upper portion of the decomposition reaction tank 31 and the ejector 8c of the air supply means 34.
[0153]
The decomposition reaction tank 31 is an airtight reaction tank. As shown in FIG. 4, the decomposition reaction tank 31 has temperature adjusting means 6 for adjusting the temperature in the tank outside the decomposition reaction tank 31, and contaminated water. The bubble generating means 32 provided at the bottom of the decomposition reaction tank 31 and connected to the air supply means 34, and the bubbles and contaminated water supplied from the bubble generating means 32 in the contaminated water The gas-liquid contactor 36 that forms a passage that enhances the contactability, the porous adsorbent 37 that is provided around the outer periphery of the gas-liquid contactor 36 and allows the contaminated water to flow through, and the contaminated water in the tank are sampled. And a sampling tube 38 for the purpose. The air passage to the exhaust gas treatment means 35 and the return air passage 33 are open at the top of the decomposition reaction tank 31.
[0154]
Further, the purification apparatus of the present embodiment has a heat pump (not shown) that simultaneously generates hot water sent to the temperature adjusting means 6 and cold water sent to the exhaust gas treatment means 35 and the condenser 9b of the return air passage 33. is doing. This heat pump uses carbon dioxide as a refrigerant, and simultaneously generates 90 ° C. hot water and 14 ° C. cold water.
[0155]
The bubble generating means 32 is an air ration nozzle and is a means for ejecting bubbles in one direction from the bottom of the decomposition reaction tank 31 upward. The gas-liquid contactor 36 forms a passage of contaminated water from the vicinity of the bottom of the decomposition reaction tank 31 to the vicinity of the liquid surface, and a plurality of slopes extending obliquely with respect to the vertical direction are formed in this passage. The adsorbent 37 is, for example, a donut-shaped porous body formed by adhering a spherical carrier, and the surface of the carrier has a pore size distribution (for example, a pore size distribution) of 1 or more times the molecular size of the contaminant. Zeolite having pores with a center diameter of about 0.6 to 10 nm is supported. The carrier may be made of zeolite.
[0156]
As a suitable example of the gas-liquid contactor 36, for example, a film-type filler shown in FIG. This film-type filler is a stack of a plurality of films that form a plurality of slopes with respect to the flow path of the fluid, and one film is a bellows fold formed by a mountain fold and a valley fold. And the other accordion folds formed by valley folds and mountain folds, and the surfaces formed by both accordion folds are connected to each other by a surface formed obliquely with respect to the folds of the accordion folds. A connecting surface portion, and such a shape is expanded in the planar direction. When a liquid phase containing bubbles is passed between the films of the filler, the flow rate of the liquid phase is continuously changed, and the contact between the bubbles and the liquid phase is improved.
[0157]
Next, an embodiment of the purification method of the present invention (the first purification method described above) that purifies contaminated water using the purification device in the present embodiment will be described.
First, contaminated water is introduced into the decomposition reaction tank 31.
[0158]
When the contaminated water is introduced into the decomposition reaction tank 31, the temperature adjusting means 6 heats the inside of the decomposition reaction tank 31 to the optimum temperature of the aerobic microorganism to be used, and maintains the inside of the decomposition reaction tank 31 at the optimum temperature. The temperature in the decomposition reaction tank 31 is measured by the temperature detection means 10 from the start of heating to the end of reaction.
[0159]
Further, the pH of the contaminated water is measured by the pH detection means 23 from the start of heating to the end of the reaction. In addition, when the pH of contaminated water is unsuitable for the activity of microorganisms, you may adjust pH of contaminated water with well-known pH adjusters, such as an acid, an alkali, and a buffer solution.
[0160]
When the temperature in the decomposition reaction tank 31 is maintained at the optimum temperature, oxygen necessary for the growth of microorganisms is supplied to the contaminated water by the air supply means 34. Bubbles are generated from the bubble generating means 32 by the supply of air. When bubbles are generated from the bubble generating means 32, a water flow of contaminated water that flows upward in the gas-liquid contactor 36 is formed. This water flow passes through the gas-liquid contactor 36 and then flows down around the gas-liquid contactor 36. After passing through the adsorbent 37, the water flow reaches the airflow generation means 36 again. In this way, a circulating flow of contaminated water is formed, and the dissolved oxygen concentration in the contaminated water becomes a saturated concentration corresponding to the contaminated water temperature. The dissolved oxygen concentration of the contaminated water is measured by the oxygen concentration detection means 11 from the start of air supply to the end of the reaction.
[0161]
In the contaminated water, a predetermined water flow is formed by the bubble generating means 32 and the gas-liquid contactor 36, and the contaminated water having a saturated dissolved oxygen concentration passes through the adsorbent 37. By passing the contaminated water through the adsorbent 37, the chlorine compound in the contaminated water is physically adsorbed on the zeolite, and the chlorine compound concentration on the adsorbent surface 37 is higher than the chlorine compound concentration in the contaminated water.
[0162]
When the optimum temperature, pH and dissolved oxygen concentration are confirmed, a medium (for example, cultivation of soybean protein or tryptosoy) and an aerobic microorganism (for example, Midosuji, optimum temperature: 65 ° C.) are put into the decomposition reaction tank 31. . The decomposition reaction of chlorine compounds in the contaminated water starts by the input of aerobic microorganisms.
[0163]
The aerobic microorganisms circulate in the decomposition reaction tank 31 on the flow of contaminated water, but a part of the aerobic microorganisms land on the adsorbent 37 when passing through the adsorbent 37. On the other hand, as described above, the chlorine compound is physically adsorbed on the surface of the adsorbent 37, and the microbial decomposition reaction of the chlorine compound proceeds on the surface of the adsorbent 37. That is, the microbial decomposition reaction of the chlorine compound is performed in a state where the concentration of the chlorine compound is relatively high and a saturated concentration of oxygen is supplied.
[0164]
In the decomposition reaction tank 31, gases such as air, solution mist, and vapor components are generated along with the decomposition reaction. Some of these gases are processed by the exhaust gas processing means 35. The exhaust gas is cooled by the cooler 9b and separated into a liquid component, a soluble gas component, and a gas component by the gas-liquid separator 9b.
[0165]
A part of the gas passes through the return air passage 33, is cooled by the cooler 9 b, separated into agglomerated components and non-aggregated components, and then sent to the ejector 8 c and supplied again to the decomposition reaction tank 31. The
[0166]
The contaminated water in the decomposition reaction tank 31 is sampled from the sampling tube 38 as necessary, such as every predetermined time, and the substrate decomposition rate is analyzed from the number concentration of microorganisms and the substrate concentration (the compound concentration) in the sample contaminated water.
[0167]
After confirming the predetermined decomposition rate, the treated water is discharged from the decomposition reaction tank 31. As described above, the discharged treated water is discharged through a sterilization process, a cooling process, or the like as necessary when discharged directly into a river or the like. In the case of draining to a sewage treatment facility, it is not necessary to perform a sterilization process.
The above operation is repeated to purify contaminated water continuously.
[0168]
According to the present embodiment, the use of the adsorbent described above and the flow of contaminated water can further enhance the contact between the chlorine compound in the pollutant and the microorganisms that decompose it on the adsorbent, Contaminated water can be purified efficiently.
[0169]
Further, according to the present embodiment, since the aerobic microorganism having a high optimum temperature is used, the contaminated water can be purified faster than the normal temperature bacteria, the decomposition reaction by the microorganism can be further purified, and the system It is easier to maintain the atmosphere inside, and is more effective from the viewpoint of industrial purification of contaminated water.
[0170]
Further, according to the present embodiment, since the bubble generating means and the gas-liquid contactor described above are used, it is more effective in increasing the dissolved oxygen concentration in the microbial decomposition reaction system, and the increase of bubbles in the contaminated water. Since the contaminated water is caused to flow by the flow generated along with this, it is more effective in saving power in the purification reaction.
[0171]
In addition, according to the present embodiment, since the heat pump that simultaneously generates the cold water supplied to the condenser in the exhaust gas treatment unit and the hot water supplied to the temperature adjustment unit is provided, it is more effective in simplifying the configuration of the purification device. It is.
[0172]
In addition, according to the present embodiment, since the return air passage is provided, it is more effective in stabilizing the optimum conditions of microorganisms and saving the power of the purification device.
[0173]
Moreover, according to this Embodiment, since contaminated water can be purified with an integrated reaction tank, it is much more effective in downsizing the purification device.
[0174]
<Fourth embodiment>
In the present embodiment, the first purification device described above is used as a purification device, an aerobic microorganism is used, and an embodiment of the present invention for purifying contaminated soil containing chlorine compounds such as dioxins as contaminants Will be described. In addition, about the structure similar to embodiment mentioned above, the same code | symbol is used and the description is abbreviate | omitted.
[0175]
As shown in FIG. 6, the purification apparatus in the present embodiment includes a decomposition reaction tank 41, an air supply means 44 that is an oxygen supply means for supplying oxygen to the contaminated soil accommodated in the decomposition reaction tank 41, and a decomposition reaction. An exhaust gas treatment means 35 for treating the gas discharged from the tank 41, a temperature detection means 10 for detecting the temperature in the tank, and an oxygen concentration detection means 11 for detecting the oxygen concentration in the tank are provided. This purification device is connected to a microwave heat sterilization drying device 3 through a screw type conveyor 4.
[0176]
The air supply means 44 has the same configuration as the air supply means 34 described above except that it does not have an ejector.
[0177]
The decomposition reaction tank 41 is an airtight reaction tank. The decomposition reaction tank 41 has temperature adjusting means 6 for adjusting the temperature in the tank outside the decomposition reaction tank 41. In the tank, rotational power such as a geared motor is provided. A rotatable rotating shaft 42 connected to the source and a plurality of cylindrical bodies 43 fixed to the rotating shaft 42 are provided. The rotating shaft 42 is provided horizontally in the tank. Each cylindrical body 43 is provided so that the longitudinal direction thereof is orthogonal to the rotation shaft 42, and when viewed from the shaft end toward the extending direction of the rotation shaft 42, adjacent cylindrical bodies are In order not to overlap, the axes of adjacent cylindrical bodies are provided so as to intersect at a predetermined angle (for example, 45 °).
[0178]
The cylindrical body 43 has a length that is about the distance from the rotary shaft 42 to the wall surface and bottom surface of the decomposition reaction tank 41, and the central portion of the cylindrical body 43 has a configuration similar to that of the gas-liquid contactor 36 described above. It is comprised by the air contactor 46, and the both ends of the cylindrical body 43 are comprised by the cylindrical member connected via a flange. For the solid-air contactor 46, for example, the film interval may be adjusted or a film having a larger crease interval may be used according to the fluidity of the contaminated soil.
[0179]
Moreover, the purification apparatus of the present embodiment has a heat pump (not shown) that simultaneously generates hot water sent to the temperature adjusting means 6 and cold water sent to the condenser 9b of the exhaust gas treatment means 35. This heat pump uses carbon dioxide as a refrigerant, and simultaneously generates 90 ° C. hot water and 14 ° C. cold water.
[0180]
Next, an embodiment of the purification method of the present invention (the first purification method described above) that purifies contaminated soil using the purification device of the present embodiment will be described.
First, the contaminated soil is put into the decomposition reaction tank 41.
[0181]
When the contaminated soil is put into the decomposition reaction tank 41, the inside of the decomposition reaction tank 41 is heated to the optimum temperature of the aerobic microorganism to be used by the temperature adjusting means 6, and the inside of the decomposition reaction tank 41 is maintained at the optimum temperature. The temperature in the decomposition reaction tank 41 is measured by the temperature detection means 10 from the start of heating to the end of reaction.
[0182]
When the temperature in the decomposition reaction tank 41 is maintained at an optimum temperature, oxygen necessary for the growth of microorganisms is supplied to the contaminated soil by the air supply means 44. The dissolved oxygen concentration in the contaminated soil is measured by the oxygen concentration detection means 11 from the start of air supply to the end of the reaction.
[0183]
On the other hand, aerobic microorganisms (for example, Midosuji) are pre-cultured in the presence of zeolite particles having pores with a pore size distribution equivalent to 1 or more times the molecular size of the chlorine compound, and the aerobic microorganisms are implanted. Prepare the adsorbent. When the optimum temperature and the oxygen concentration in the tank are confirmed, the adsorbent on which the microorganisms are implanted and the medium (for example, soy protein or tryptoise) are introduced into the decomposition reaction tank 41. Decomposition reaction of chlorine compounds in contaminated soil is started by the input of aerobic microorganisms.
[0184]
The contaminated soil and adsorbent in the tank are agitated and uniformly mixed by the rotation of the rotating shaft 42 and the outer peripheral wall of the cylindrical body 43. With the mixing of the contaminated soil and the adsorbent, the chlorine compound in the contaminated soil is physically adsorbed on the adsorbent, and the concentration of the chlorine compound on the surface of the adsorbent increases. If the surface of the adsorbent is formed of the zeolite, the form thereof is not particularly limited. As shown in the third embodiment, the zeolite is supported on an appropriate carrier such as a granule. It may be what was done.
[0185]
On the other hand, the contaminated soil and adsorbent in the tank are scooped into the cylindrical body 43 from one open end of the cylindrical body 43 by the rotation of the rotating shaft 42. The scooped contaminated soil and adsorbent flow in the cylindrical body 43 that is inclined as the rotating shaft 42 rotates, and pass through the solid-gas contactor 46. In the solid-gas contactor 46, since the wall surface of the passage forms a slope, the flow velocity of the flowing contaminated soil and the like continuously changes, and the contact between the flowing contaminated soil and the atmosphere in the tank is improved. To do.
[0186]
That is, in the purification apparatus of the present embodiment, the decomposition reaction is also performed in the decomposition reaction tank 41, but oxygen is easily supplied to microorganisms when the contaminated soil passes through the solid-gas contactor 46, and the solid-gas contactor 46. A more efficient microbial degradation reaction is performed in
[0187]
Contaminated soil or the like that has passed through the solid-gas contactor 46 flows to the other opening end of the cylindrical body 43 as the rotating shaft 42 rotates, and part or all of the contaminated soil is discharged out of the cylindrical body from the other opening end. . The other open end scoops contaminated soil and the like in the decomposition reaction tank 41 as the rotating shaft 42 rotates, and this time the contaminated soil and the like flow from one end to the other in the same manner. In addition, about the process of the gas generated with a decomposition | disassembly, it is the same as that of 3rd Embodiment mentioned above.
[0188]
The contaminated soil in the decomposition reaction tank 41 is sampled as necessary, such as every predetermined time, and the substrate decomposition rate is analyzed from the number concentration of microorganisms and the substrate concentration (the compound concentration) in the sample-contaminated soil.
[0189]
After confirming the predetermined decomposition rate, the treated soil is discharged from the decomposition reaction tank 41 by the screw type conveyor 4. This treated soil is sterilized by the microwave heat sterilization drying apparatus 3 to obtain a purified treated soil.
The above operation is repeated to continuously purify the contaminated soil.
[0190]
In the present embodiment, the air supply means 44 or the decomposition reaction tank 41 may be provided with a humidifying means for adjusting the humidity in the system. Providing such a humidifying means is effective in further adjusting the growth conditions of microorganisms.
[0191]
Moreover, in this Embodiment, you may fix the stirring blade for stirring the contaminated soil in a tank to the rotating shaft 42 between the cylindrical bodies 43. FIG. Providing such a stirring blade is effective in mixing the contaminated soil in the tank more evenly and further improving the contact between the contaminated soil and the atmosphere in the tank.
[0192]
In the present embodiment, the end of the cylindrical body 43 may be processed. For example, when the end of the cylindrical body 43 has a shape in which the rotation direction side of the rotating shaft 42 is cut away, it is preferable for scooping contaminated soil in the tank. Further, when the end of the cylindrical body 43 has a shape in which the rear side in the rotation direction of the rotary shaft 42 is cut out, it is preferable for discharging contaminated soil in the cylindrical body from the cylindrical body.
[0193]
According to the present embodiment, the contact between the adsorbent and the microorganism mixed with the microorganism is made to flow to increase the contact between the microorganism and oxygen, and the contact between the chlorine compound in the pollutant and the microorganism that decomposes the adsorbed is adsorbed. Since it is further enhanced on the material, the contaminated soil can be efficiently purified.
[0194]
In addition, according to the present embodiment, since aerobic microorganisms having a high optimum temperature are used, contaminated soil can be purified faster than normal temperature bacteria, and the decomposition reaction by these microorganisms can be further purified. It is easier to maintain the atmosphere inside and is more effective from the viewpoint of industrial purification of contaminated soil.
[0195]
In addition, according to the present embodiment, since the heat pump that simultaneously generates the cold water supplied to the condenser in the exhaust gas treatment unit and the hot water supplied to the temperature adjustment unit is provided, it is more effective in simplifying the configuration of the purification device. It is.
[0196]
In addition, according to the present embodiment, the contaminated soil can be purified with an integrated reaction tank, which is more effective in downsizing the purification device.
[0197]
Further, according to the present embodiment, since the end of the tubular body is connected to the tubular body main body by the flange, the processing of the end of the tubular body as described above, the replacement of the end, and the rotating shaft Maintenance such as adjustment of the angle of the cylindrical body 43 with respect to 42 and replacement of the solid-gas contactor 46 can be easily performed, the amount of contaminated soil introduced into the cylindrical body, and contamination in the decomposition reaction tank 41 It is more effective in controlling the agitation of soil and the like.
[0198]
<Fifth embodiment>
In the present embodiment, the first purification device described above is used as a purification device, an aerobic microorganism is used, and an embodiment of the present invention for purifying contaminated soil containing chlorine compounds such as dioxins as contaminants Will be described. In addition, about the structure similar to embodiment mentioned above, the same code | symbol is used and the description is abbreviate | omitted.
[0199]
As shown in FIG. 8 and FIG. 9, the purification device in the present embodiment includes a temperature adjustment tank 51, a rotation shaft 52 provided in the temperature adjustment tank 51, and a plurality provided orthogonal to the rotation shaft 52. The cylindrical decomposition reaction tank 53 is provided.
[0200]
The temperature adjustment tank 51 is a means for adjusting the temperature in the decomposition reaction tank 53 by circulatingly supplying a heat medium such as hot water or steam to the inside, and extends in a direction perpendicular to the paper surface in FIG. It is composed of a closed cylinder. Although not shown, this cylindrical body has a heat medium supply port for supplying a heat medium to the inside and a heat medium discharge port for discharging the heat medium from the inside, and is provided to be opened and closed by a hinge structure. For example, it is divided into two parts in the axial direction, and these are joined by a hinge structure, the upper half in FIG. 8 is opened upward and the lower half is fixed, and is fixedly attached to the rotating shaft 52 and the decomposition reaction tank 53. ing. A packing is provided at the opening edge. The rotating shaft 52 is connected to a geared motor as a rotational power source.
[0201]
The decomposition reaction tank 53 is provided so as to extend from the rotation shaft 52, and is provided in two stages in the axial direction of the rotation shaft 52, with three being one stage, and three are equal to the rotation direction of the rotation shaft 52. It is provided at intervals (the angle of each axis is 120 °). The decomposition reaction tank 53 has a proximal end closed and a distal end sealed with an openable / closable lid. A solid-gas contactor 46 is provided inside each decomposition reaction tank 53.
[0202]
Next, an embodiment of the purification method of the present invention (the first purification method described above) that purifies contaminated soil using the purification device of the present embodiment will be described.
First, the lid of the decomposition reaction tank 53 is opened, and the contaminated soil and the adsorbent on which microorganisms have been deposited are introduced into the decomposition reaction tank 53 as in the fourth embodiment described above.
[0203]
When the contaminated soil is put into the decomposition reaction tank 53, the lid is closed, the temperature adjustment tank 51 is sealed, the rotating shaft 52 is rotated, and a heat medium is further introduced into the temperature adjustment tank 51 so that the temperature in the tank is reduced to the temperature of the microorganism. Heat to temperature and maintain.
[0204]
The decomposition reaction tank 53 is inclined so that the base end side and the tip end side are alternately directed downward by the rotation of the rotating shaft 52. The contaminated soil and adsorbent introduced into the decomposition reaction tank 53 pass back and forth between the proximal end side and the distal end side in the decomposition reaction tank 53 through the solid-gas contactor 46 in the reaction decomposition tank 53.
[0205]
Due to the inclination of the decomposition reaction tank 53 accompanying the rotation of the rotating shaft 52, the contaminated soil and the adsorbent are sufficiently mixed, and the chlorine compound in the contaminated soil is sufficiently in contact with the adsorbent and physically adsorbed on the adsorbent. Moreover, the mixture of contaminated soil and adsorbent is sufficiently brought into contact with air by moving through the solid-gas contactor 46. Further, the inside of the microbial decomposition reaction system is kept at an optimum temperature by the temperature adjusting tank 51. Therefore, the chlorine compound is efficiently decomposed by microorganisms on the surface of the adsorbent.
[0206]
The contaminated soil in the decomposition reaction tank 53 is sampled as necessary, such as every predetermined time, and the substrate decomposition rate is analyzed from the number concentration of microorganisms and the substrate concentration (the compound concentration) in the sample-contaminated soil.
[0207]
After confirming the predetermined decomposition rate, the treated soil is taken out from the decomposition reaction tank 53. This treated soil is sterilized by a sterilization means such as a microwave heat sterilization drying apparatus, and purified treated soil is obtained.
The above operation is repeated to continuously purify the contaminated soil.
[0208]
In the present embodiment, no oxygen supply means is particularly provided for the decomposition reaction tank 53. However, for example, a lid or the like is provided with a vent provided with a filter or the like in the decomposition reaction tank 53, so that the heating medium of the temperature adjustment tank 51 is used. Steam or heated air may be used.
[0209]
According to the present embodiment, the temperature suitable for the microbial decomposition reaction is maintained in the decomposition reaction tank 53, and the contaminated soil and the adsorbent are sufficiently in contact with the air. In a sufficiently secured system, the contact between the chlorine compound in the contaminated soil on the adsorbent surface and the microorganisms that decompose it is further increased, and the contaminated soil can be efficiently purified.
[0210]
Moreover, according to this Embodiment, since it has the some decomposition reaction tank 53, it is still more effective in purifying simultaneously several types of the small amount contaminated soil from which a pollutant differs with microorganisms.
[0211]
【The invention's effect】
According to the present invention, in a pollutant purification method and purification apparatus for decomposing and purifying pollutants containing chlorine compounds by microorganisms in a system in which the temperature is adjusted, an adsorbent and a chlorine compound that physically adsorb chlorine compounds Since microorganisms having an optimal temperature for decomposing at least 60 ° C or more are present in the contaminants and the contaminants are caused to flow in the system, the adsorbent is removed in the system in which the action of the cold bacteria is excluded. In this case, the contact property between the chlorine compound and the microorganism and the oxygen supply ability to the microorganism can be further increased, and the purification can be performed with higher speed and reproducibility.
[0212]
Furthermore, in the present invention, when an aerobic microorganism having an optimum temperature of 65 ° C. or higher is used and a chlorine compound is decomposed in a system in which oxygen is supplied by an oxygen supply means, the apparatus and work procedure can be simplified and reproduced at high speed. It is even more effective in performing sexual purification.
[0213]
Furthermore, in the present invention, when a gas contactor that forms a passage that enhances the contact between the fluid and the gas is used, and contaminants are caused to flow in the gas contactor, high-speed and reproducible purification is achieved. More effective.
[0214]
Furthermore, in the present invention, when an adsorbent that physically adsorbs the chlorine compound is further added to the contaminant, the chlorine compound is physically adsorbed and the microorganisms are implanted, thereby improving the contact between the chlorine compound and the microorganisms, and at high speed and efficiency. It is more effective for purification, and when zeolite having pores with a pore size distribution equivalent to 1 or more times the molecular size of the chlorine compound is used as the adsorbent, the chlorine compound is physically adsorbed and the microorganisms are removed. It is even more effective in implanting, improving the contact between the chlorine compound and the microorganism, and performing high-speed and efficient purification.
[0215]
Further, according to the present invention, at least a rotating shaft provided in the horizontal direction in the decomposition reaction tank and a cylindrical body which is provided orthogonal to the rotating shaft and spills contaminated soil in the tank at the end as the rotating shaft rotates. When used as a means, a solid-gas contactor that forms the passage in a cylindrical body is used as a gas contactor, which is more effective in purifying contaminated soil containing chlorine compounds, and adsorption that physically adsorbs chlorine compounds. It is more effective to add more materials into the reaction system.
[0216]
Furthermore, in the present invention, a rotating shaft provided in the horizontal direction is used as a flow means, and a cylindrical body provided perpendicular to the rotating shaft and closed at the end and capable of containing contaminated soil is used as a decomposition reaction tank. Use of a solid-gas contactor that forms the passage in the cylindrical body as a gas contactor is more effective in purifying contaminated soil containing chlorine compounds, and an adsorbent that physically adsorbs chlorine compounds. Further addition to the reaction system is even more effective.
[0217]
Furthermore, in the present invention, a gas-liquid contact is used which uses a bubble generating means connected to the oxygen supply means and generates bubbles from the bottom of the decomposition reaction tank into the passage of the gas contactor as the flow means, and forms the passage in the contaminated water. If the layered adsorbent is used in the gas contactor and passes through the flow of contaminated water that is fixed in the decomposition reaction tank and passes through the gas-liquid contactor, it is more effective in purifying contaminated water containing chlorine compounds. More effective.
[0218]
Furthermore, in the present invention, if the exhaust gas is processed by cooling the gas discharged from the decomposition reaction tank with a condenser, it is effective in suppressing the influence on the surrounding environment of the apparatus, and the refrigerant and heat supplied to the condenser and the temperature adjusting means are effective. When the medium is generated by a heat pump, it is more effective in simplifying the configuration of the apparatus.
[0219]
Further, according to the present invention, in the system in which the temperature is adjusted, the pollutant containing the chlorine compound is decomposed and purified by the microorganism, and the chlorine in the pollutant is removed by the dechlorination microorganism having an optimum temperature of 60 ° C. or higher. Decomposing a compound, removing chlorine from the pollutant, and then decomposing the compound contained in the pollutant from which chlorine has been removed by the dechlorinating microorganism by the compound decomposing microorganism having an optimum temperature of 65 ° C or higher Compared to the conventional case of using room temperature bacteria, contaminants can be purified more quickly, and the effects of various bacteria can be eliminated, so that the contaminant purification reaction can be purified and reproducible purification is possible. It can be performed.
[0220]
Furthermore, in the present invention, a dechlorination step is performed using an aerobic microorganism as a dechlorination microorganism in a system from which oxygen is removed, and then an aerobic microorganism is used as a compound decomposition microorganism in a system where oxygen is supplied. When the compound decomposition step is performed, it is more effective in purifying contaminants with high speed and reproducibility.
[0221]
Furthermore, in the present invention, if the gas discharged in the dechlorination process is processed, the influence of the exhaust gas on the surrounding environment can be suppressed, and further, the processing gas can be reused. It is more effective in maintaining a suitable environment for the activity of microorganisms in each process.
[0222]
Furthermore, in the present invention, detecting the oxygen concentration and temperature of the system in each process is more effective in maintaining a suitable environment for the activity of microorganisms in each process, and ensures reproducibility of the purification reaction. It is more effective in doing. Furthermore, when the contaminant is contaminated water, detecting the pH of the system in each process is more effective in maintaining a favorable environment for the activity of microorganisms in each process, and also reproduces the purification reaction. It is even more effective in securing the sex.
[Brief description of the drawings]
FIG. 1 is a schematic view showing an embodiment of a second purification device in the present invention.
FIG. 2 is a schematic view showing another embodiment of the second purification device in the present invention.
FIG. 3 is a schematic view showing an embodiment of a first purification device in the present invention.
4 is an enlarged schematic view of a main part showing the vicinity of a decomposition reaction tank of the purification apparatus shown in FIG. 3. FIG.
FIG. 5 is a schematic configuration diagram showing a structure of a preferred example of a gas contactor according to the present invention.
FIG. 6 is a schematic view showing another embodiment of the first purification device in the present invention.
7 is a schematic view of the main part showing the rotating shaft and the vicinity of a cylindrical body of the purification device shown in FIG. 6;
FIG. 8 is a schematic front view showing another embodiment of the first purification device of the present invention.
9 is a schematic side view showing a main part of the purification device shown in FIG.
[Explanation of symbols]
1,21 Stirring tank for dechlorination
2,22 Compound decomposition tank
3 Microwave heating sterilization drying equipment
4, 5 Screw type conveyor
6 Temperature adjustment means
7 Stirrer for solid phase
8 Nitrogen supply means (oxygen removal means)
8a Nitrogen cylinder
8b Nitrogen supply pipe
8c Ejector
9, 29 Exhaust gas treatment means for dechlorination
9a, 14c compressor
9b Cooler (condenser)
9c Gas-liquid separator
9d adsorber
9e Humidifier
10 Temperature detection means
11 Oxygen concentration detection means
14, 34, 44 Air supply means (oxygen supply means)
14a Air supply source
14b Air supply pipe
15, 25 Exhaust gas treatment means for compound decomposition
23 pH detection means
27 Stirrer for liquid phase
31, 41, 53 Decomposition reactor
32 Bubble generation means
33 Return air vent
35 Exhaust gas treatment means
36 Gas-liquid contactor
37 Adsorbent
38 Sampling tube
42, 52 Rotating shaft
43 Tubular body
46 Solid-gas contactor
51 Temperature control tank

Claims (6)

A pollutant purification device for decomposing and purifying pollutants containing chlorine compounds by microorganisms,
A decomposition reaction tank for containing at least a microorganism that decomposes a chlorine compound in the contaminant, the contaminant, and an adsorption component that physically adsorbs the contaminant, and decomposes the contaminant;
Temperature adjusting means for adjusting the temperature in the decomposition reaction tank;
A flow means for flowing the contaminant in the decomposition reaction tank;
Oxygen supply means for supplying oxygen into the decomposition reaction tank;
A gas contactor that forms a passage that enhances the contact between the fluid and the gas,
The microorganism is an aerobic microorganism having an optimum temperature of 65 ° C. or higher,
In the purifying apparatus, wherein the flow means is means for flowing the contaminant in at least the passage of the gas contactor,
The pollutant is contaminated soil, and the flow means is disposed at least in a horizontal direction in the decomposition reaction tank, and a contaminated soil in the tank is provided perpendicularly to the rotation axis. An apparatus for purifying contaminants , which is a cylindrical body scooped at an end, and wherein the gas contactor is a solid-gas contactor that forms the passage in the cylindrical body. A pollutant purification device for decomposing and purifying pollutants containing chlorine compounds by microorganisms,
A decomposition reaction tank for containing at least a microorganism that decomposes a chlorine compound in the contaminant, the contaminant, and an adsorption component that physically adsorbs the contaminant, and decomposes the contaminant;
Temperature adjusting means for adjusting the temperature in the decomposition reaction tank;
A flow means for flowing the contaminant in the decomposition reaction tank;
Oxygen supply means for supplying oxygen into the decomposition reaction tank;
A gas contactor that forms a passage that enhances the contact between the fluid and the gas,
The microorganism is an aerobic microorganism having an optimum temperature of 65 ° C. or higher,
In the purifying apparatus, wherein the flow means is means for flowing the contaminant in at least the passage of the gas contactor,
The contaminant is contaminated soil, the flow means is a rotating shaft provided at least in the horizontal direction, the decomposition reaction tank is provided orthogonal to the rotating shaft, the end is closed, and the contaminated soil is contained inside A pollutant purification apparatus, wherein the gas contactor is a solid-gas contactor that forms the passage in the cylindrical body. The contaminant purification apparatus according to claim 1 or 2 , wherein a particulate adsorbent that physically adsorbs the chlorine compound is added to the decomposition reaction tank. A pollutant purification device for decomposing and purifying pollutants containing chlorine compounds by microorganisms,
A decomposition reaction tank for containing at least a microorganism that decomposes a chlorine compound in the contaminant, the contaminant, and an adsorption component that physically adsorbs the contaminant, and decomposes the contaminant;
Temperature adjusting means for adjusting the temperature in the decomposition reaction tank;
A flow means for flowing the contaminant in the decomposition reaction tank;
Oxygen supply means for supplying oxygen into the decomposition reaction tank;
A gas contactor that forms a passage that enhances the contact between the fluid and the gas,
The microorganism is an aerobic microorganism having an optimum temperature of 65 ° C. or higher,
In the purifying apparatus, wherein the flow means is means for flowing the contaminant in at least the passage of the gas contactor,
The contaminant is contaminated water, and the flow means is a bubble generating means that is connected to the oxygen supply means and generates bubbles from the bottom of the decomposition reaction tank into the passage of the gas contactor. The vessel is a gas-liquid contactor that forms the passage in the contaminated water, and the adsorption component is a layered adsorbent that is fixed in the decomposition reaction tank and allows the flow of contaminated water that has exited from the gas-liquid contactor to pass through. Contaminant purification device characterized by the above . The pollutant purification device according to claim 3 or 4 , wherein the adsorbent is a zeolite having pores having a pore size distribution equivalent to 1 or more times the molecular size of the chlorine compound. An exhaust gas processing means having a condenser for cooling the gas discharged from the decomposition reaction tank and processing the gas discharged from the decomposition reaction tank; a heat pump for generating a refrigerant and a heat medium to be supplied to the capacitor and the temperature adjusting means The contaminant purification apparatus according to any one of claims 1 to 5, wherein:

Images