JP2011131199A - Wastewater treatment method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a means which enables cost reduction and can decolorize colored wastewater under a mild condition without exerting a bad influence on the human body and the environment. <P>SOLUTION: In a wastewater treatment method, dyes in the colored wastewater are reacted with enzymes extracted from a waste mushroom bed after cultivation of basidiomycetes to decompose the dyes, thereby decolorizing the colored wastewater. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a wastewater treatment method and a wastewater treatment apparatus for decolorizing dyes in colored wastewater discharged from, for example, a dye factory.

  In recent years, dye wastewater (colored wastewater) discharged in large quantities from dyeing factories or the like has become a problem in relation to environmental problems, and regulations on dye wastewater have been strengthened by local governments and the like. Dye is highly colored and difficult to decolorize even at low concentrations. Conventionally, dye wastewater is taken up by a specialist processor and outsourced to be disposed of as industrial waste or discharged into rivers, etc.・ Purification and other treatments have been made. In such a case, the place where the waste is disposed and the place where the wastewater treatment facility is located are limited, and the treatment cost of the dye wastewater tends to increase due to the above-mentioned tightening regulations. As a method of decomposing, a method of decomposing by contacting a dye with ozone (for example, see Patent Document 1), a treatment method using a microorganism (for example, see Patent Document 2), and the like are attracting attention.

JP-A-9-239383 Japanese Patent Laid-Open No. 2000-287664

  However, in the case of wastewater treatment with ozone, it has been pointed out that it affects the human body because it is involved in the production of carcinogenic compounds. On the other hand, in the case of using microorganisms, it is necessary to adjust the reaction conditions to the growth conditions of the microorganisms, and thus it is difficult to adjust the treatment conditions. There is a problem that there is. Moreover, in any of the above cases, there is also a drawback that a great deal of cost is required for the equipment (ozone generator, backing tank).

  The present invention has been made in view of such problems, and is a wastewater treatment method having a structure capable of decolorizing colored wastewater under mild conditions without adversely affecting the human body and the environment while reducing costs. And an object of the present invention is to provide a wastewater treatment apparatus.

  In order to achieve the above-mentioned object, the wastewater treatment method according to the present invention reacts with a dye in colored wastewater and an enzyme extracted from a waste fungus bed after cultivation of basidiomycetes, and decomposes the dye, thereby coloring the dye. It is the structure which decolors drainage.

  In the wastewater treatment method having the above-described configuration, it is preferable to purify the membrane filtrate by separating the product produced as a result of the decomposition treatment of the dye from the wastewater decolorized by the enzyme in the waste bed by membrane filtration.

  The wastewater treatment apparatus according to the present invention is a wastewater treatment apparatus for decolorizing colored wastewater containing a dye, and the colored wastewater is introduced and extracted from the dye in the colored wastewater and the waste fungus bed after basidiomycete cultivation. A decomposition treatment tank for decolorizing the colored waste water by reacting with the enzyme and decomposing the dye is provided.

  In addition, the wastewater treatment apparatus having the above-described configuration includes membrane separation means for separating the product generated as a result of the decomposition treatment of the dye from the wastewater decolorized in the decomposition treatment tank, and purifying the membrane filtrate by membrane filtration. Preferably, it is configured.

  Further, in the wastewater treatment apparatus having the above-described configuration, the membrane separation means separates the wastewater decolorized in the decomposition treatment tank into a membrane concentrated water containing a product resulting from the decomposition treatment of the dye and a membrane filtered water. It is preferable to be provided with an apparatus.

  According to the wastewater treatment method and the wastewater treatment apparatus according to the present invention, by effectively using an enzyme having a dye-decomposing ability extracted from a waste fungus bed remaining after cultivation of basidiomycetes, the cost is reduced and the human body and the environment are adversely affected. It becomes possible to decolor the colored wastewater under mild conditions without exerting any effect.

It is a flowchart which shows an example of the waste water treatment apparatus suitable for enforcing the waste water treatment method which concerns on this invention.

  Hereinafter, preferred embodiments of the present invention will be described. The wastewater treatment method according to the present invention is characterized in that the colored wastewater is decolorized by reacting the dye in the colored wastewater with the enzyme extracted from the waste fungus bed after cultivation of basidiomycetes and decomposing the dye. To do.

  As dyes to be used in the present invention, azo dyes, phthalocyanine dyes, acridine dyes, triphenylmethane dyes, triazine dyes, and the like are applicable, but are not limited thereto. Among them, examples of the azo dye mainly used as the dye include monoazo dyes such as Acid Orange 20 and Acid Violet 3, diazo dyes such as Direct Blue 2, triazo dyes, and tetraazo dyes, but are not limited thereto. Is not to be done.

  The basidiomycete used in the present invention is not particularly limited as long as it is a basidiomycete having an enzyme capable of degrading the dye. For example, Pleurotus salmoneostramineus, Agaricus edible mushrooms such as bisporus, armillariella mellea, enokitake (Flammulina velutipes), shiitake (Lentinus edodes), mushroom (Pnellus serotinus), eringi (Pleurotus eryngii), oyster mushroom (Pleurotus ostreatus), etc. Among basidiomycetes, wood-rotting fungi and white-rotting fungi are preferably used.

  The waste bed of basidiomycetes is, for example, a bed (medium) remaining after artificial cultivation of basidiomycetes, and is a mixture of sawdust, medium additive (nutrient additive), water, etc. Will not be adversely affected. Moreover, effective utilization of the basidiomycetes waste microbial bed conventionally discarded in large quantities can also be aimed at.

  The basidiomycete-derived enzyme used in the present invention is a laccase generally produced by basidiomycetes (especially abundantly in wood-rotting fungi and white-rotting fungi), and this laccase is basically various. It is an active enzyme that catalyzes the one-electron oxidation of a substrate (for example, a phenolic compound). In addition, even if it is the enzyme named the same laccase, the property changes with kinds of said basidiomycete, and active conditions, such as a substrate which acts suitably, optimal temperature, and optimal pH, differ. Moreover, the same basidiomycete may have a plurality of laccases having different properties. Therefore, at least one or more types of laccase extracted from the waste fungus bed of the basidiomycete group are used. That is, you may use combining multiple types of laccase.

  As an action of laccase, for example, an electron (hydrogen) is extracted from phenols (electron donor) in a dye, and the electron is passed to an oxygen molecule (electron acceptor) to catalyze a chemical reaction that generates water. . In this process, it is presumed that the structure related to the chromophore of the dye is destroyed and decolorization of the dye occurs. With regard to this laccase reaction, it is possible to proceed under mild conditions.

  Here, as a method of measuring the decoloring ability (decoloring activity) using the above enzyme, colored waste water is collected at regular intervals, and the absorbance (decrease rate of absorbance) of the maximum absorption wavelength of the dye is measured. It is preferable to estimate the decolorization rate.

  When the enzyme (laccase) and the dye are reacted as described above, a product (residue) corresponding to the component of the dye is generated as a result. Therefore, it is preferable to provide a membrane separation means for separating the decolored waste water from the product after the dye decomposition treatment. As the membrane separation means, a membrane concentration method in which the product is separated into concentrated membrane water and permeated water is preferable.

  Next, a waste water treatment apparatus suitable for carrying out the waste water treatment method of the present invention will be described. FIG. 1 is a flowchart showing an example of a wastewater treatment apparatus according to the present embodiment, and a schematic configuration of the wastewater treatment apparatus will be described with reference to this figure.

  The waste water treatment apparatus 1 is broadly divided into a storage tank 2 for temporarily storing waste water containing dye (hereinafter referred to as colored waste water), and a decomposition for decolorizing the colored waste water supplied from the storage tank 2. A treatment tank 4 and a membrane concentrator 11 that captures a product remaining in the treatment liquid decolorized in the decomposition treatment tank 4 are configured.

  The storage tank 2 temporarily stores, as raw water, colored wastewater (dye wastewater) discharged from, for example, a printing apparatus or a dyeing factory. The colored wastewater in the storage tank 2 is sucked up by the feed pump 3 and fed to the decomposition treatment tank 4. In order to increase the efficiency of the treatment in the decomposition treatment tank 4, a preheating means for preheating the colored wastewater staying in the storage tank 2 before being introduced into the decomposition treatment tank 4 to a water temperature suitable for the enzyme activity in advance. It may be provided.

  The decomposition treatment tank 4 is filled with the dye wastewater introduced by the feed pump 3, and the wastewater treatment agent 6 containing an enzyme (laccase) for decomposing the dye is introduced into the dye wastewater. The enzyme used in the wastewater treatment agent 6 is extracted by filtration or the like after the enzyme is eluted by adding a buffer solution to a basidiomycete waste bed or a pulverized product thereof and stirring.

  As the buffer, for example, ammonium acetate or phosphoric acid is applied, and the pH is not particularly limited as long as the enzyme activity to be extracted is maintained. Examples of the waste water treatment agent 6 include an enzyme solution which is a supernatant obtained by centrifuging an extract from a buffer solution, and an enzyme preparation obtained by freeze-drying the enzyme solution. Examples of the enzyme preparation include powdered ones and those obtained by shaping the tablets into tablets (tablets). In particular, if the wastewater treatment agent 6 is made into a tablet, its handling becomes easy and the weight per one becomes constant. Therefore, an appropriate dose (addition amount) for the colored wastewater to be treated is set to the tablet. It can be calculated with the number. In addition, you may comprise the processing agent injection | throwing-in apparatus which administers the waste water processing agent 6 automatically in the decomposition processing tank 4 at predetermined time intervals, for example.

  In the decomposition treatment tank 4, the dye in the colored wastewater reacts with the enzyme of the wastewater treatment agent 6 to decolorize the dye (colored wastewater). A stirring device 5 for stirring the colored waste water is installed in the decomposition treatment tank 4, thereby increasing the chance of contact between the dye of the colored waste water and the enzyme of the waste water treatment agent 6. Further, in order to promote the reaction between the dye and the enzyme, a water temperature adjusting means for adjusting the temperature of the colored waste water, or a pH adjusting means for adjusting the pH by adding hydrochloric acid or phosphoric acid solution to the colored waste water may be provided.

  The decomposition treatment tank 4 is connected with an absorbance measuring device 7 for measuring the absorbance of the waste water after decoloring treatment (hereinafter referred to as treated water). The absorbance measurement device 7 intermittently or continuously extracts part of the treated water, measures the absorbance of the treated water, and outputs this measurement information to the control unit 8. As the absorbance measuring device 7, for example, a flow cell type ultraviolet visible absorptiometer is exemplified. This absorptiometer transmits light in the same wavelength band as the dye pigment wavelength and measures the transmittance to determine the absorbance of the dye.

  When the control unit 8 determines that the measured absorbance is equal to or less than a predetermined value set in advance based on the measurement information input from the absorbance measurement device 7, that is, the decolorization process is sufficiently performed, the control unit 8 is provided in the decomposition tank. The opened electromagnetic valve 9 is opened, and the decomposition treatment tank 4 and the membrane concentrator 11 are communicated with each other via the feed pump 10. For example, the residence time (treatment time) of the colored wastewater in the decomposition treatment tank 4 is measured by a timer counter without providing the absorbance measurement device 7, and the electromagnetic valve 9 is opened as the prescribed residence time elapses. It is good also as a structure made to valve.

  The treated water decolorized in the decomposition treatment tank 4 is sucked up by the feed pump 10 and fed to the membrane concentrator 11 at the next stage. Here, decolorization of a dye is not limited to decolorization to colorless and transparent, but is a concept including discoloration and color reduction.

  The membrane concentrating device 11 has a separation membrane 12 for separating the treated water decolorized by the waste water treatment agent 6 into the membrane permeated water W1 and the membrane concentrated liquid W2. As the separation membrane 12, an organic membrane or an inorganic membrane such as a microfiltration membrane (microfilter) or an ultrafiltration membrane can be applied. In addition, as the form of the separation membrane 12, a flat membrane type, a hollow fiber type, a spiral type, a cylindrical (tubular) type, a pleat type, and the like can be appropriately employed as the membrane module. The pore size of the separation membrane varies depending on, for example, the case of the microfiltration membrane and the case of the ultrafiltration membrane, but an appropriate one is selected according to the product to be trapped.

  In the membrane concentrator 11, a part of the treated water introduced permeates the separation membrane 12 by the transmembrane pressure and flows into the membrane permeate receiving tank 13 as the membrane permeate W1. The membrane permeated water W1 guided to the membrane permeated water receiving layer 13 is finally discharged into a river or the like after being subjected to pH treatment, for example. On the other hand, impurities such as products produced by the previous enzymatic decomposition are blocked by the separation membrane 12 and discharged out of the system as membrane concentrated water W2. The membrane concentrated water W2 (product) drawn out of the system intermittently or continuously from the membrane concentrator 11 is dehydrated by, for example, the dehydrator 14 and then discarded.

  As described above, according to the wastewater treatment method and wastewater treatment apparatus according to the present embodiment, by effectively using an enzyme (laccase) having a dye-decomposing ability extracted from a waste fungus bed remaining after cultivation of basidiomycetes. In addition to reducing costs, it is possible to provide wastewater treatment means capable of decolorizing colored wastewater under mild conditions without adversely affecting the human body and the environment.

  In addition, by providing a membrane concentrating device (membrane separation means) that captures a product generated as a result of the decolorization treatment, it is possible to purify the decolorized treated water to a quality that can be discharged into public water such as rivers. .

  Although the preferred embodiment of the present invention has been described so far, the present invention is not limited to this embodiment. For example, in the above-described embodiment, the configuration in which the colored wastewater to be decolorized is once introduced into the storage tank 2 has been described as an example. However, the present invention is not limited to this and is directly introduced into the decomposition treatment tank 4. It may be configured to.

  Moreover, in the above-mentioned embodiment, although the structure which provided only one decomposition treatment tank 4 was illustrated and demonstrated, it is not limited to this, For example, a some decomposition treatment tank is connected in series It may be provided and divided into a dirty tank and a clean tank, or may be configured to circulate between a plurality of decomposition treatment tanks.

  Furthermore, in the above-described embodiment, the configuration provided with the membrane concentrating device 11 as the membrane filtration means at the subsequent stage of the decomposition processing means has been described as an example. However, the present invention is not limited to this. A membrane filtration means having a two-stage configuration in which a microfiltration membrane (microfilter) is arranged in the first stage and an ultrafiltration membrane is arranged in the second stage may be used. Further, for example, a solid-liquid separation means such as a sedimentation separation method (sedimentation basin) or a pressure flotation method may be further provided before or after the membrane filtration means.

  In the above-described embodiment, the configuration in which the treatment liquid decolorized in the decomposition treatment tank 4 is introduced into the membrane concentrator 11 by the feed pump 10 has been described as an example, but is not limited thereto. For example, the supernatant liquid of the decomposition treatment tank 4 may be supplied to the membrane concentration apparatus 11.

  Furthermore, in the above-mentioned embodiment, although the structure using the waste water treatment agent 6 containing an enzyme (laccase) was illustrated and demonstrated, for example, the waste microbial bed itself (the waste microbial bed was processed into an appropriate size) May be used as a wastewater treatment agent. Moreover, you may comprise by adding the additive which accelerates | stimulates enzyme activity (laccase activity) to a waste water treatment agent.

DESCRIPTION OF SYMBOLS 1 Waste water treatment device 2 Storage tank 3 Feeding pump 4 Decomposition processing tank 5 Stirring device 6 Waste water treatment agent 7 Absorbance measuring device 8 Control part 9 Electromagnetic valve 10 Feeding pump 11 Membrane concentrator (membrane separation means)
12 Separation membrane 13 Membrane permeate receiving tank 14 Dehydrator W1 Membrane permeate W2 Membrane concentrate

Claims (5)

  A wastewater treatment method comprising: decolorizing the colored wastewater by reacting the dye in the colored wastewater with an enzyme extracted from a waste fungus bed after cultivation of basidiomycetes to decompose the dye.   The wastewater treatment according to claim 1, wherein a product obtained as a result of decomposing the dye is separated by membrane filtration from the wastewater decolorized by an enzyme in the waste bed to purify the membrane filtrate. Method. A wastewater treatment device for decolorizing colored wastewater containing a dye,
Decomposition treatment that decolorizes the colored wastewater by introducing the colored wastewater, reacting the dye in the colored wastewater with the enzyme extracted from the waste fungus bed after basidiomycete cultivation, and decomposing the dye A waste water treatment apparatus comprising a tank.   Membrane separation means for separating the product resulting from the decomposition treatment of the dye from the waste water decolorized in the decomposition treatment tank by membrane filtration to purify the membrane filtered water is provided. The wastewater treatment apparatus according to claim 3.   The membrane separation means includes a membrane concentrating device that separates the waste water decolorized in the decomposition treatment tank into a membrane concentrated water containing a product resulting from the decomposition treatment of the dye and a membrane filtered water. The waste water treatment apparatus according to claim 4.

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