JP2009066515A - Method, device, and agent for decoloring dye-containing wastewater - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a decoloring method, device and agent which can easily decolor colored wastewater containing hardly decomposable coloring-causing substances at a low cost. <P>SOLUTION: The decoloring method for dye-containing waste-water comprises the process for introducing the dye-containing wastewater into a treatment tank, and the process for adding calcium chloride and a microorganism belonging to Enterococcus genus to the introduced wastewater. The decoloring device is equipped with a means for introducing the dye-containing wastewater into the treatment tank, a means for adding calcium chloride and the microorganism belonging to Enterococcus genus to the introduced wastewater, a means for adjusting pH of the wastewater in the treatment tank, a means for controlling the wastewater in the treatment tank from a microaerophilic condition to an aerobic condition, and a means for leading out the wastewater in the treatment tank. The decoloring agent for dye-containing wastewater contains calcium chloride and the microorganism belonging to Enterococcus genus. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a decolorization treatment method for wastewater, a decolorization treatment apparatus, and a decolorization treatment agent used therefor. In detail, it is related with the decoloring processing method of the wastewater containing dye, the decoloring processing apparatus, and the decoloring processing agent used for it.

Currently, wastewater containing dyes (hereinafter referred to as colored wastewater) is generated in factories of various industries such as dye manufacturing factories, fiber dyeing factories, paper / pulp dyeing factories, and food processing plants. This colored wastewater contains dyes such as direct dyes, acid dyes, reactive dyes, cationic dyes, sulfur dyes, and disperse dyes as coloring cause components.
In these various dyes currently used, the ratio of azo dyes is large, and it is said that it accounts for about 70% of the total. Azo dyes are characterized by a chemical structure that is stable and difficult to be decomposed, and it is very difficult to decompose and decolorize only by a normal activated sludge method. Therefore, as a decolorization technique for colored wastewater, a coagulation precipitation method, an activated carbon adsorption method, or an oxidative decomposition method using ozone or the like is used alone or in combination.

  Aggregation and precipitation methods include inorganic flocculants such as aluminum salts (such as aluminum sulfate, sodium aluminate and basic aluminum chloride), iron salts (such as ferrous sulfate, ferric sulfate and ferric chloride) and organic polymers. This is a technique in which a flocculant (an anionic polymer, a cationic polymer, a nonionic polymer, etc.) is added to waste water to coagulate and remove coloring-causing components such as dyes.

  However, the coagulation precipitation method has a problem in that a large amount of mud-like secondary waste containing a color-causing component such as a dye is generated, and the cost for treating these wastes is high. Further, this means has a problem that it cannot be applied to a low-molecular color-causing component having high water solubility and poor aggregation.

  In the activated carbon adsorption method, decolorization is usually performed by a filtration device filled with activated carbon, but there is a problem that the filtration device is likely to be clogged, and operation maintenance may be complicated. In addition, there is a problem that enormous costs are required to regenerate or discard the used activated carbon.

  In addition, the oxidative decomposition treatment method using ozone requires the introduction of special equipment such as an ozone generator and the problem of high power consumption and high running costs. Application to the treatment of colored wastewater was not feasible.

  Therefore, many of the above-mentioned methods have problems such as high processing cost and complicated operation and maintenance, and there is a need for a decoloring processing method that is inexpensive and highly effective.

  Thus, as a method other than the chemical and physical treatments, a method for treating colored wastewater using microorganisms has been studied. Microbial treatment is believed to have the advantage of low processing costs at scale-up.

  As an example of a treatment method using such a microorganism, a decolorization apparatus for decolorizing and denitrifying wastewater by bringing wastewater containing a dye into contact with sulfate-reducing bacteria, nitrifying bacteria, and denitrifying bacteria (Patent Document 1) Microorganisms belonging to the genus Rhodopseudomonas and / or Rhodobacter sphaeroides having azo dye resolution and those relating to the degradation of azo dyes using the same (Patent Document 2), the genus Klebsiella, the genus Flavobacterium and the Aeromonas ( And a decoloring agent for dyes containing one or more microorganisms selected from the genus Aeromonas) and a decoloring method using the same (Patent Document 3).

  However, these methods have a problem of low versatility with respect to actual wastewater containing various dyes and coloring components because of the high specificity of microbial dyes. Furthermore, the actual colored wastewater discharged from the factory is not only the dyes that cause coloration, but also the raw materials, by-products, dispersants, solubilizers, surfactants, leveling agents, and fixants used at the production site. In some cases, a large amount of a processing agent such as an agent, a sizing agent or a soaping agent is contained. Since these compounds inhibit the growth of microorganisms, there has been a problem that the above-described method cannot maintain the growth of microorganisms and a sufficient decoloring effect cannot be obtained.

  Patent Documents 4, 5, 6 and 7 describe wastewater treatment methods using Enterococcus microorganisms. However, these methods are intended for purification of domestic wastewater, and there are cases where a sufficient decoloring effect cannot be obtained for persistent dyes. In addition, decolorization of colored wastewater when using Enterococcus microorganisms alone requires long-term treatment with high-concentration bacteria, which increases the amount of suspension in the treated supernatant. There was a problem.

  Furthermore, Patent Document 8 describes a method of decoloring by adding a microorganism belonging to the genus Pseudomonas and calcium chloride to a coloring solution. However, in this method, first, it is necessary to prepare a culture condition in which Pseudomonas microorganisms produce an aggregating substance. That is, nutrients that can be used by microorganisms such as high concentrations of glucose and yeast extract must be added to the wastewater, resulting in an increase in the concentration of organic matter in the wastewater and an increase in the wastewater treatment load. .

  For these reasons, there is still a strong demand for a treatment method that is suitable for treatment of actual factory wastewater and has a low decolorization effect and high cost.

JP 2004-82107 A JP 2002-45172 A JP 2002-28691 A JP 2000-51891 A JP 2003-80290 A JP 2003-334588 A JP 2005-270735 A Japanese Patent Application Laid-Open No. 6-276992

  The present invention has been made in view of such problems of the prior art, and a decolorization treatment method and a decolorization treatment capable of easily decolorizing colored wastewater containing a hardly decomposable coloring cause substance at low cost. An object is to provide an apparatus and a decoloring agent.

  That is, the present invention relates to a method for decolorizing wastewater containing a dye, including a step of introducing wastewater containing a dye into a treatment tank and a step of adding calcium chloride and a microorganism belonging to the genus Enterococcus to the introduced wastewater. About.

  It is preferable that the waste water in the treatment tank has a pH of 6.0 to 9.0 and a calcium chloride concentration of 0.003 to 0.3% by weight.

  It is preferable that the microbial concentration of the wastewater in the treatment tank is 1000 to 10,000 mg / L in terms of dry weight.

  It is preferable that the microorganism is derived from activated sludge and the wastewater is in a microaerobic condition.

  Further, the present invention provides means for introducing waste water containing a dye into a treatment tank, means for adding calcium chloride and a microorganism belonging to the genus Enterococcus to the introduced waste water, means for adjusting the pH of waste water in the treatment tank The present invention also relates to a decoloring apparatus comprising means for controlling waste water in the treatment tank from a microaerobic condition to an aerobic condition, and means for deriving the waste water in the treatment tank.

  Furthermore, this invention relates to the decoloring treatment agent of the wastewater containing a dye containing the calcium chloride and the microorganisms which belong to the genus Enterococcus.

  According to the present invention, by using calcium chloride and a microorganism belonging to the genus Enterococcus, it is possible to easily decolorize colored wastewater, which is safe, low in cost, and practical in that there is little suspension of the treated supernatant. An excellent decolorization treatment method, decolorization treatment apparatus, and decolorization treatment agent can be provided.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows one embodiment of a decoloring apparatus according to the present invention, which is a means for introducing waste water containing a dye into a treatment tank, and calcium chloride and microorganisms belonging to the genus Enterococcus are added to the introduced waste water. Means, means for adjusting the pH of the wastewater in the treatment tank, means for controlling the wastewater in the treatment tank from a microaerobic condition to an aerobic condition, and means for deriving the wastewater in the treatment tank It is a schematic diagram which shows a decoloring processing apparatus.

  In FIG. 1, reference numeral 1 denotes a waste water supply pipe as waste water introduction means, reference numeral 2 denotes a treatment tank, and reference numeral 3 denotes a treated water discharge pipe as waste water deriving means. Further, as means for adjusting pH, a measuring instrument 4 for measuring pH, a control device 5 for controlling an input amount of acid or alkali according to the value, an acid and alkali storage tank 6 and an acid or alkali supply pipe 7 are provided. As means for adding calcium chloride and microorganisms belonging to the genus Enterococcus, a microorganism storage tank 8, a microorganism supply pipe 9, a calcium chloride storage tank 11 and a calcium chloride supply pipe 12, and further from a microaerobic condition to an aerobic condition A stirring means 10 or an air feeding means (not shown) is provided as a control means.

  The treatment tank 2 is not particularly limited as long as it can be decolorized by adding calcium chloride and a microorganism belonging to the genus Enterococcus. For example, a complete mixing type in which continuous stirring or intermittent stirring is performed, or a fluidized bed type in which a microorganism-immobilized support is introduced can be used.

  Moreover, the decoloring apparatus of this invention may be equipped with the precipitation tank, the dehydrator, the concentrator, etc. as a solid-liquid separation means for isolate | separating microorganisms and treated water in the back | latter stage of the processing tank 2. FIG.

  Furthermore, even if the decoloring apparatus of this invention is used independently, it may be installed and used in the front | former stage or back | latter stage of the conventional activated sludge processing tank.

  In the present invention, wastewater to be treated is colored wastewater containing direct dyes, acid dyes, reactive dyes, cationic dyes, sulfur dyes, disperse dyes and the like, and is not particularly limited. Especially, since the high decoloring effect can be acquired when the total organic carbon amount (TOC) in colored wastewater is the range of 100-3000 mg / L, it is preferable. When the total organic carbon content (TOC) is lower than 100 mg / L, the microorganism's dye-decomposing function may not be activated due to a lack of nutrient sources for microorganisms. In this case, an organic substance serving as a nutrient source for microorganisms can be added to the colored wastewater to adjust the TOC concentration, and can be applied to the method of the present invention. On the other hand, when the total organic carbon content (TOC) is higher than 3000 mg / L, organic matter that is easily biodegraded is present in the wastewater to be treated at a high concentration. The effect may not be obtained. In addition, secondary water pollution problems such as increase in sludge, accumulation of metabolites, and generation of rot odor may occur.

  The method of adding the calcium chloride and the microorganism belonging to the genus Enterococcus used in the present invention is not particularly limited, and may be added to the colored wastewater after mixing in advance, or may be added independently to the colored wastewater. . In any case, a synergistic decoloring effect can be obtained.

  The pH of the color wastewater to be treated in the treatment tank is preferably maintained at 6.0 to 9.0. If it is out of this range, the activity of the microorganisms is lowered, so that a sufficient decoloring effect may not be obtained. In addition, when calcium chloride is added to wastewater having a pH higher than 9.0, aggregates such as hydroxide may be formed. Particularly preferably, the pH is 6.5 to 8.5.

  The present invention is characterized in that calcium chloride and a microorganism belonging to the genus Enterococcus are used in combination. The details of the decolorization mechanism by calcium chloride and Enterococcus microorganisms have not been fully elucidated, but calcium acts on the extracellular layer to increase the ability to adsorb dyes and stabilize various microorganism-derived enzymes. It is thought that it synergistically increases the decoloring activity of microorganisms.

  Calcium chloride is widely present in the natural environment such as seawater, and is known as a relatively low-cost substance with low toxicity.

  The calcium chloride concentration of the color wastewater to be treated is preferably 0.003 to 0.3% by weight, more preferably 0.005 to 0.2% by weight, and still more preferably 0.01 to 0.2% by weight. It is. When the calcium chloride concentration is within this range, the decoloring effect can be synergistically enhanced. When the concentration is lower than 0.003% by weight, the effect of addition becomes insufficient, and a synergistic decoloring effect with microbial treatment tends to be difficult to obtain. Even if the concentration exceeds 0.3% by weight, no further effect of addition tends to be obtained, and excessive calcium remains in the treated water, which may lead to deterioration of water quality. The amount of calcium chloride added to the colored wastewater can be appropriately adjusted within the above-mentioned concentration range according to the type of wastewater, the degree of coloring, the water quality required for the treated wastewater, and the like.

  The microorganism used in the present invention belongs to the genus Enterococcus. Enterococcus is generally capable of growing under conditions of high salt concentration and in a wide pH range, so that it grows well in waste water and has an excellent decolorizing effect when calcium chloride is used in combination.

  Furthermore, when a microorganism belonging to the genus Enterococcus is used, there is an advantage that decolorized water with less suspended substances and high transparency and excellent water quality can be obtained. Microorganisms belonging to the genus Enterococcus are generally characterized as cocci that do not have motility, and are superior in sedimentation of microorganisms compared to the genus Pseudomonas having motility and other types of microorganisms. Therefore, separation of the treated water and the microorganisms after the decoloring treatment is easy, and for example, highly transparent treated water can be obtained as a supernatant after stationary separation, so that the practicality is extremely high.

  Moreover, it is known as a kind of lactic acid bacteria, and has high safety and can be suitably used for wastewater treatment. The microorganism is not particularly limited as long as it belongs to the genus Enterococcus. Examples include Enterococcus faecalis, Enterococcus malodoratus, Enterococcus avium and the like. Of these, Enterococcus abium, which is excellent in growth under low nutrient conditions, is preferable.

  Examples of the microorganism belonging to the genus Enterococcus used in the present invention include, but are not limited to, Enterococcus avium species, NBRC100477, JCM8722, ATCC 14025, DST0703, NCTC 9938, and the like. is not.

  In addition, the microorganism is preferably derived from activated sludge in that it has high adaptability to wastewater to be treated and is less susceptible to adverse effects on the surrounding environment.

  This microorganism is collected from, for example, activated sludge in a wastewater treatment facility of a fiber dyeing factory. The collected activated sludge is appropriately diluted and applied to an SCD agar medium (Nissui Pharmaceutical Co., Ltd.) containing 0.03% reactive dye (C.I. Reactive Red 3). After culturing at 25 ° C. for 24 hours, it is obtained by isolating one microorganism having a high decolorization effect from the colony that has formed a decolorization halo. The present inventors analyzed the base sequence of the 16S rDNA upstream region (about 500 bp) of the isolated microorganism according to a conventional method and identified it by BLAST database search. As a result, the present bacterium was found to be a 16S rDNA base of Enterococcus It was found to be highly homologous to the sequence and was identified as a microorganism belonging to the genus Enterococcus.

  In the present invention, the wastewater to be treated in the treatment tank may contain microorganisms other than those belonging to the genus Enterococcus, such as microorganisms derived from activated sludge, and in this case, synergistically with a plurality of microorganisms. Water purification function.

  Furthermore, the microorganism in the present invention can be used in a state of being supported on a carrier. The carrier to be used is not particularly limited, and examples thereof include fibrous structures, porous bodies, and gel-like bodies made of cellulose, polyethylene, polypropylene, polyester, polystyrene, acrylic, polyurethane, carbon fiber, activated carbon, zeolite, polyvinyl alcohol, and the like. It is done.

  The concentration of the microorganism belonging to the genus Enterococcus used in the present invention is preferably 1000 to 10,000 mg / L in dry weight, more preferably 1000 to 9000 mg / L, and still more preferably 2000 to 8000 mg / L. It is. Even when the microbial concentration is lower than 1000 mg / L, a decoloring effect can be obtained, but the treatment may take a long time. On the other hand, when it is larger than 10000 mg / L, a high decoloring effect can be obtained, but the solid-liquid separation between the treated water and the microorganisms after the decoloring process becomes difficult, and the wastewater treatment process may be complicated.

  The ratio of the microorganism belonging to the genus Enterococcus and calcium chloride used in the present invention is not particularly limited, but the microorganism belonging to the genus Enterococcus: calcium chloride is in a dry weight of 1: 0.03 to 1: 3. This is preferable because a high decolorization effect can be obtained synergistically.

  The decolorization treatment agent of the present invention preferably comprises a microorganism belonging to the genus Enterococcus and calcium chloride in the above ratio, that is, a dry weight of 1: 0.03 to 1: 3.

  Examples of the form include powder and suspension.

  Examples of the decoloring agent include various carbon sources, protein, peptone, yeast extract, meat extract, carbon dioxide sources such as amino acids, various inorganic salts such as potassium phosphate, sodium chloride, magnesium sulfate, sodium nitrate, and ammonium sulfate. In general, components necessary for activating microorganisms may be included. For example, microorganism-derived components such as solubilized sludge and yeast extract, and grain residues such as rice bran may be included as those having a high activation effect on microorganisms and inexpensive.

  The decoloring treatment of the present invention is preferably performed within the range of slightly aerobic conditions to aerobic conditions in that a high decoloring effect can be obtained.

  The aerobic condition in the present invention is a condition in which the redox potential (ORP) is preferably in the range of 300 to 0 mV, more preferably in the range of 250 to 50 mV, and active aeration stirring is performed, such as using an aeration apparatus. . The oxidation-reduction potential (ORP) can be measured with a general ORP meter (Ag / AgCl electrode).

  In the present invention, the microaerobic condition refers to a range in which the redox potential (ORP) is preferably 0 to −250 mV, more preferably −30 to −200 mV. Such microaerobic conditions can be controlled by standing or gently stirring the colored wastewater to which microorganisms have been added.

  When the oxidation-reduction potential (ORP) exceeds 300 mV, dead bodies and decomposition products of microorganisms are likely to be generated, and the quality of treated water may be deteriorated. On the other hand, when the oxidation-reduction potential (ORP) is lower than −250 mV, it becomes close to an anaerobic state, so that the reaction necessary for decolorization does not easily proceed efficiently, and problems such as the generation of rot odor may occur.

  Especially, since aeration using an aeration pump etc. is unnecessary, it is preferable to perform a decoloring process on microaerobic conditions at the point that an installation is compact and a running cost can be reduced.

  EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not restrict | limited at all by an Example.

Decolorization effect on model colored wastewater <Preparation of model colored wastewater containing dye>
A model colored waste water was prepared by adding 10 ml of SCD liquid medium (manufactured by Nissui Pharmaceutical), 90 ml of water, and 0.03 ml of reactive dye (CIReactive Red 3). The pH of this wastewater was 6.8.

Example 1
To 100 ml of the model-colored wastewater, 0.05 g of calcium chloride and 0.2 g of Enterococcus abium (NBRC 100477, purchased from National Institute of Technology and Evaluation) were added in terms of dry weight. Enterococcus abium cells were collected in advance after culturing in an SCD liquid medium and centrifuged. The dry weight of the microbial cells was determined by using a part of the collected microbial cells and using an infrared moisture meter FD-610 (Kett Science Laboratory Co., Ltd.) under drying conditions at 105 ° C.
The prepared colored wastewater was placed in a treatment tank (200 ml plastic wide-mouthed bottle) and allowed to stand to make a microaerobic condition, and a decolorization treatment was performed at 25 ° C. for 24 hours.

Example 2
Decolorization treatment was performed in the same manner as in Example 1 by adding 0.2 g of calcium chloride and 0.2 g of Enterococcus abium (NBRC100477) in terms of dry weight to 100 ml of the model colored waste water.

Example 3
Decolorization treatment was performed in the same manner as in Example 1 by adding 0.05 g of calcium chloride and 0.6 g of Enterococcus abium (NBRC100477) to 100 ml of the model colored waste water.

Example 4
Decolorization treatment was performed in the same manner as in Example 1 by adding 0.2 g of calcium chloride and 0.6 g of Enterococcus abium (NBRC100477) to 100 ml of the model colored waste water.

Comparative Example 1
A model colored wastewater not containing microorganisms belonging to the genus Calcium chloride and Enterococcus was placed in a treatment tank (200 ml plastic wide-mouth bottle) and allowed to stand at 25 ° C. for 24 hours.

Comparative Example 2
Only 100 g of calcium chloride was added to 100 ml of the model colored waste water, and the decolorization treatment was performed in the same manner as in Example 1.

Comparative Example 3
Only 100 g of Enterococcus abium (NBRC100477) in terms of dry weight was added to 100 ml of the model colored waste water, and the color removal treatment was performed in the same manner as in Example 1.

Comparative Example 4
To 100 ml of the model colored waste water, 0.2 g of calcium chloride and 0.6 g of Klebsiella microorganism (NBRC13277) in terms of dry weight were added, and decolorization treatment was performed in the same manner as in Example 1. As the microorganism belonging to the genus Klebsiella, a microorganism collected in advance after centrifugation in an SCD liquid medium was used.

Comparative Example 5
To 100 ml of the model-colored waste water, 0.2 g of calcium chloride and 0.6 g of Pseudomonas microorganisms (NBRC13275) in terms of dry weight were added, and decolorization treatment was performed in the same manner as in Example 1. The microorganism belonging to the genus Pseudomonas was previously cultured in an SCD liquid medium and then collected by centrifugation.

Decolorization effect on actual wastewater from textile dyeing factory <Preparation of wastewater sample>
Colored wastewater containing disperse dyes, reactive dyes, surfactants, pastes, etc. was collected from a textile dyeing factory. As a result of measuring the total organic carbon amount and the total nitrogen amount of this colored wastewater with a TOC meter (manufactured by Shimadzu Corporation), the total organic carbon amount was 295 mg / L and the total nitrogen amount was 69 mg / L. Sulfuric acid was added to the colored wastewater to adjust the pH to 7.8 and used for the following decolorization test.

Example 5
0.2 g of calcium chloride was added to 100 ml of colored waste water collected from the fiber dyeing factory. Further, 0.6 g of the above-mentioned Enterococcus abium (NBRC 100477, purchased from the National Institute of Technology and Evaluation) was added in terms of dry weight. Subsequently, the wastewater was placed in a treatment tank (200 ml plastic wide-mouthed bottle) and allowed to stand to make a microaerobic condition, and decolorization treatment was performed at 25 ° C. for 16 hours.

Comparative Example 6
Decolorization treatment was carried out at 25 ° C. for 16 hours in the same manner as in Example 5 without adding calcium chloride and microorganisms belonging to the genus Enterococcus to 100 ml of colored wastewater collected from the fiber dyeing factory.

Comparative Example 7
Only 0.2 g of calcium chloride was added to 100 ml of colored waste water collected from the above-mentioned fiber dyeing factory, and decolorization treatment was performed at 25 ° C. for 16 hours in the same manner as in Example 5.

Comparative Example 8
To 100 ml of colored waste water collected from the fiber dyeing factory, 0.6 g of Enterococcus abium (NBRC100477) in terms of dry weight was added, and decolorization treatment was performed at 25 ° C. for 16 hours in the same manner as in Example 5.

Comparative Example 9
To 100 ml of colored waste water collected from the fiber dyeing factory, 0.2 g of calcium chloride and 0.6 g of microorganisms belonging to the genus Pseudomonas (Pseudomonas aeruginosa: NBRC13275) in terms of dry weight were added. Decolorization treatment was performed at 25 ° C for 16 hours.

<Evaluation of decoloring effect>
As an index of the degree of coloration in the colored wastewater, the absorbance in the visible light region (350 nm to 700 nm) of the colored wastewater was measured at 1 nm intervals, and the integrated value (hereinafter referred to as integrated absorbance) was obtained. Furthermore, the decolorization rate (%) was calculated from the following equation. For measuring the absorbance, each colored wastewater filtered through a filter having a pore size of 0.45 μm was used. Note that UV-2450 (manufactured by Shimadzu Corporation) was used for measurement of absorbance and calculation of integrated absorbance.
Decolorization rate (%) = ((A ₀ −A ₁ ) / A ₀ ) × 100
A ₀ : Integrated absorbance of colored wastewater before decolorization treatment A ₁ : Integrated absorbance of colored wastewater after decolorization treatment

<Evaluation of turbidity of supernatant after decolorization treatment>
The supernatant of the waste water after decoloring treatment was collected, and the absorbance (turbidity of the supernatant) at a wavelength of 610 nm was measured. The lower the absorbance, the less the suspended matter that causes pollution and the better the quality of the wastewater after treatment.

Decoloring effect on model wastewater When both calcium chloride and microorganisms were not added (Comparative Example 1) and when only calcium chloride was added (Comparative Example 2), no decoloring effect was obtained. In addition, when only the microorganism belonging to the genus Enterococcus was added (Comparative Example 3), the decolorization rate was about 68%, but it did not reach the example.

  Further, in Comparative Example 4 and Comparative Example 5 to which calcium chloride and microorganisms other than Enterococcus were added, there was obtained a decolorization rate close to 70%, but the turbidity of the treated wastewater supernatant was very high. The quality of the treated water was inferior.

  On the other hand, in Examples 1 to 4, in which calcium chloride and microorganisms belonging to the genus Enterococcus were added to colored wastewater and subjected to decolorization treatment under slightly aerobic conditions by standing, a high decoloration effect was obtained synergistically in any case. The decolorization rate was 70% or more. Furthermore, the turbidity of the supernatant of wastewater was 0.7 or less in all examples.

  Therefore, the Example has a high decoloring effect with respect to colored wastewater, and can obtain the treated water with few suspended solids.

Decoloring effect on actual waste water of textile dyeing factory When both calcium chloride and microorganisms were not added (Comparative Example 6) and when only calcium chloride was added (Comparative Example 7), no decoloring effect was obtained. Further, when only the microorganism belonging to the genus Enterococcus was added (Comparative Example 8), the decolorization rate was about 63%, but it did not reach the example.

  Further, in Comparative Example 9 to which calcium chloride and microorganisms other than Enterococcus were added, although a decolorization rate of about 70% was obtained, the turbidity of the supernatant of the treated wastewater was as high as 5.0, and the treated water The water quality was inferior and the practicality was low.

  On the other hand, in Example 5, a microorganism belonging to the genus Calcium chloride and Enterococcus was added to the colored wastewater to obtain a high decolorization rate of 75%. Furthermore, the turbidity of the supernatant of the wastewater at this time was 0.9, and treated water with good suspended water quality with few suspended substances could be obtained.

  Furthermore, the absorption spectrum measurement result of the treated waste water of Example 5 and Comparative Examples 6, 7 and 8 is shown in FIG. In the treated wastewater of Example 5, it was confirmed that the absorbance in the visible light region was significantly reduced, and it was confirmed that the treatment wastewater was extremely effective in decolorizing the actual wastewater.

<Isolation and analysis of microorganisms belonging to the genus Enterococcus>
The activated sludge from the wastewater treatment facility of the textile dyeing factory was collected, diluted as appropriate, and applied to an SCD agar medium (Nissui Pharmaceutical Co., Ltd.) containing 0.03% of reactive dye (CIReactive Red 3). After culturing at 25 ° C. for 24 hours, one kind of microorganism having a high decolorization effect was isolated from the colony that formed the decolorization halo. According to a conventional method, the base sequence of the upstream region (about 500 bp) of the 16S rDNA of the isolated microorganism was analyzed and identified by database search by BLAST. As a result, this bacterium was found to be highly homologous to the base sequence of 16S rDNA belonging to the genus Enterococcus, and was identified as a microorganism belonging to the genus Enterococcus.

  Using the microorganism of the genus Enterococcus isolated from this activated sludge, the same evaluation as in Examples 1 to 5 was carried out. As a result, commercially available Enterococcus Similar to abium (NBRC100477), it was confirmed to show a high decoloring effect.

It is a schematic diagram which shows one Embodiment of the decoloring processing apparatus of this invention. The base sequence data of about 500 bp upstream region of 16S rDNA of microorganisms belonging to the genus Enterococcus of the present invention are shown. It is a graph which shows the absorption-spectrum measurement result of Example 5 and the treatment wastewater of Comparative Examples 6, 7, and 8.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Waste water supply pipe 2 Treatment tank 3 Treated water discharge pipe 4 pH measuring device 5 Acid or alkali input amount control device 6 Acid or alkali storage tank 7 Acid or alkali supply pipe 8 Microorganism storage tank 9 Microorganism supply pipe 10 Stirring means 11 Chlorination Calcium storage tank 12 Calcium chloride supply pipe

Claims (6)

A method for decolorizing wastewater containing a dye, comprising a step of introducing wastewater containing a dye into a treatment tank, and a step of adding calcium chloride and a microorganism belonging to the genus Enterococcus to the introduced wastewater. The decoloring treatment method according to claim 1, wherein the pH of the waste water in the treatment tank is 6.0 to 9.0, and the calcium chloride concentration is 0.003 to 0.3% by weight. The decolorization method according to claim 1 or 2, wherein the microbial concentration of the wastewater in the treatment tank is 1000 to 10000 mg / L by dry weight. The decolorization treatment method according to claim 1, wherein the microorganism belonging to the genus Enterococcus is derived from activated sludge, and the wastewater is in a microaerobic condition. Means for introducing waste water containing dye into the treatment tank, means for adding calcium chloride and microorganisms belonging to the genus Enterococcus to the introduced waste water, means for adjusting the pH of waste water in the treatment tank, A decoloring apparatus comprising means for controlling wastewater from a microaerobic condition to an aerobic condition and means for deriving the wastewater in the treatment tank. A decolorizing agent for wastewater containing a dye, comprising calcium chloride and a microorganism belonging to the genus Enterococcus.

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