JP2006007016A - Wastewater treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wastewater treatment method which reduces the amount of coagulant consumption and the amount of generated sludge, almost or completely removes color, and performs color removal of wastewater in toner production. <P>SOLUTION: The wastewater treatment method targets the treatment of wastewater containing at least color components generated from production processes of an electrostatic charge image development toner, and comprises a process for removing the color components generated from the production processes by the oxidation treatment of organic matter after coagulating sedimentation treatment or pressure floatation treatment. The process for removing the color components consists of advanced oxidation treatment. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a wastewater treatment method for treating wastewater containing at least a coloring component generated from a predetermined manufacturing process.

  Conventionally, as wastewater generated from a toner manufacturing factory, wastewater containing a surfactant aqueous solution, a coloring component such as a pigment dispersion, a wax dispersion, an aqueous emulsion, or the like has been generated. Since these wastewater contains the above-mentioned surfactant, pigments which are coloring components, etc., they cannot be discharged into rivers, sewers or the like as they are. For this reason, these wastewaters are discharged outside after being treated at a wastewater treatment facility in the factory. As the wastewater treatment, coagulation sedimentation treatment is often used. Coagulation and sedimentation treatment is the most commonly used in the field of wastewater treatment, as described in the 5th edition pollution prevention technology and legal water quality edition (supervised by the Ministry of International Trade and Industry, Environmental Location Bureau, issued in 2001) p141. This is one of the solid-liquid separation operations that are widely used. The coagulation sedimentation treatment is a treatment method in which flocs (coarse particles generated by coagulation) are generated by adding a coagulant to the wastewater, and the flocs precipitate due to the difference in specific gravity between water and flocs to perform solid-liquid separation. The floc thus separated as a solid is treated as sludge for industrial waste, and the water from which the solid has been separated is discharged into rivers, sewers and the like.

  Patent Document 1 discloses an organic wastewater treatment method by using a wastewater treatment method based on a catalytic oxidation method in which an organic substance-containing wastewater is supported on a granular inorganic carrier with a catalytically active component. However, when this method is used for the treatment of an aqueous solution containing a coloring component, the mechanism is not well understood due to the action of the coloring component and the surfactant, but there arises a problem that the coloring component is difficult to remove. On the other hand, Patent Document 2 discloses a method of performing an electrochemical removal step for organic matter oxidation treatment. However, this method can treat wastewater containing organic matter, but cannot be applied as it is to all types of wastewater generated from toner manufacturing plants.

JP 2003-251375 A JP-A-6-121978

  For example, in the coagulation sedimentation treatment of wastewater containing multicomponents generated from a toner manufacturing factory, the sedimentation property in a floc sedimentation tank or the like is poor, and a very long sedimentation treatment is required for solid-liquid separation. Furthermore, in order to coagulate and precipitate colored components such as pigment dispersions contained in the waste water, it is necessary to add a large amount of a flocculant, which causes a problem that a large amount of sludge is generated as industrial waste. is there.

  Generally, when wastewater containing an aqueous surfactant solution, which accounts for 80% by weight of the total amount of wastewater discharged from the toner manufacturing process, and wastewater containing coloring components are mixed, the mechanism is not well understood, but the surface activity Due to the dispersion stabilizing action of the coloring component by the agent, the sedimentation time in the coagulation sedimentation treatment becomes longer, it becomes difficult to remove the coloring component, and the inorganic coagulant used for coagulating precipitation and removing the coloring component, for example, chloride As a result, the amount of ferrous iron increases, and as a result, a large amount of coagulated sediment, that is, a large amount of sludge to be treated as industrial waste is generated. This is probably because a certain amount of ferric chloride used as an inorganic flocculant reacts with the surfactant contained in the wastewater to neutralize the charge and inhibits the action as a flocculant.

  In recent years, the awareness of green chemicals has increased, and the removal of colored wastewater has been desired. On the other hand, it is an effective means to use activated carbon for the color removal of waste water, but there is a problem that it requires a great deal of cost to regenerate the used activated carbon.

  Accordingly, an object of the present invention is to provide a wastewater treatment method that reduces the amount of flocculant used and the amount of sludge generated and has little or no coloration.

  The present invention has the following features.

  (1) A wastewater treatment method for treating wastewater containing at least a coloring component generated from a manufacturing process of an electrostatic charge image developing toner, wherein the coloring component generated from the manufacturing process is removed by organic matter oxidation treatment. Is a wastewater treatment method.

  (2) In the wastewater treatment method according to the above (1), the step of treating the coloring component is a wastewater treatment method including accelerated oxidation treatment.

  (3) A wastewater treatment method for treating wastewater containing at least a colored component generated from a manufacturing process of an electrostatic charge image developing toner, and subjecting the wastewater containing the colored component generated from the manufacturing process to coagulation sedimentation treatment A wastewater treatment method including a step of removing by accelerated oxidation after being performed.

  (4) A wastewater treatment method for treating wastewater containing at least a colored component generated from a manufacturing process of an electrostatic charge image developing toner, wherein the wastewater containing the colored component generated from the manufacturing process is pressurized and floated. It is the wastewater treatment method provided with the process of removing by an accelerated oxidation process after performing.

  ADVANTAGE OF THE INVENTION According to this invention, the amount of flocculant used for the process of the waste_water | drain containing at least a coloring component which generate | occur | produces from a manufacturing process, and the generation amount of the sludge generated by a waste_water | drain process can be reduced. Furthermore, the treated waste water has little or no coloration, and waste water treatment considering the environment can be performed.

  As a manufacturing process that requires the waste water treatment, a toner manufacturing process will be described below as an example.

  The toner manufacturing process is roughly divided into a manufacturing process of a latex polymer that is a raw material of toner and a manufacturing method of a developing toner. Below, an example is given and demonstrated about each.

[Latex polymer production process]
In order to produce a latex polymer, a monomer and an anionic surfactant are usually added to water and stirred to form an emulsion. Once the monomer emulsion is formed, 25 wt% or less of the monomer emulsion (ie, a small amount of monomer emulsion) and the free radical initiator are added to the aqueous phase and mixed to initiate seed polymerization at the desired reaction temperature. After the seed particles are formed, a monomer emulsion is further added to the seed particle-containing composition, and polymerization is continued at a specified temperature for a desired time to complete the polymerization, thereby forming a latex polymer. When the latex polymer is formed, it is aggregated together with the colorant to form aggregate particles, which are then fused to form toner particles, as described in the developer toner production method described below. From the latex polymer production process, an emulsion aqueous solution that is no longer necessary in the production process or generated during equipment maintenance in the production process is discharged.

  The monomer is not particularly limited as long as it can react with a free radical initiator. Specific examples of the monomer include homopolymers or copolymers of styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, acrylic Homopolymers or copolymers of esters having vinyl groups such as lauryl acid, 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; acrylonitrile And homopolymers or copolymers of vinyl nitriles such as methacrylonitrile.

  Further, a resin such as polyester or polyurethane having self-emulsifying properties may be sheared and dispersed in an aqueous medium together with a surfactant. Moreover, what contains an ammonia component as a latex polymer is also used.

[Method for producing developing toner]
The latex polymer obtained by the above preparation method is used for toner preparation by the following method. A flocculant and / or a charge additive and / or other additives are mixed with the latex polymer prepared by the method described in the present invention and at least a plurality of dispersions containing a colorant, if necessary, and the resulting mixture is obtained. Is heated at a temperature near the Tg of the latex polymer, preferably Tg ± 10 ° C. of the latex polymer for an effective time, for example, 1-8 hours, to produce toner-sized aggregates. The aggregate suspension is then heated to a Tg of the latex polymer or higher, for example from about 60 to about 120 ° C. to coalesce or coalesce to granulate toner particles, which are filtered, etc. It is separated from the mother liquor by means, washed with ion exchange water or the like (washing process), and then dried.

  The latex polymer is usually used as a binder resin for toner, and is present in the toner at about 75 to 98% by weight. The size of the latex polymer suitable for the production method of the present invention can be measured with a laser diffraction type particle size distribution analyzer, for example, a volume average particle size measured with a microtrack (manufactured by Nikkiso Co., Ltd.), 0.05 to It is about 1 μm.

Examples of the colorant used in the toner in the present embodiment include carbon black, chrome yellow, hansa yellow, benzidine yellow, sren yellow, quinoline yellow, permanent orange GTR, pyrazolone orange, vulcan orange, watch young red, permanent red, and brilliant. Carmine 3B, Brilliant Carmine 6B, Dupont Oil Red, Pyrazolone Red, Risor Red, Rhodamine B Lake, Lake Red C, Rose Bengal, Aniline Blue, Ultramarine Blue, Calco Oil Blue, Methylene Blue Chloride, Phthalocyanine Blue, Phthalocyanine Green, Maracalite Various pigments such as green oxalate: acridine, xanthene, azo, benzoquinone, a Various dyes such as cyanine, anthraquinone, dioxazine, thiazine, azomethine, indico, thioindico, phthalocyanine, aniline black, polymethine, triphenylmethane, diphenylmethane, thiazole and xanthene Can be mentioned. These colorants may be used alone or in combination of two or more.

  The colorant is usually present in an effective amount in the toner, for example, about 1 to 15% by weight, preferably about 3 to 10% by weight of the toner. Moreover, the magnitude | size is a volume average particle diameter measured with this microtrack, for example, and is about 0.05-0.5 micrometer.

  The flocculant can be used in an effective amount, for example, about 0.01 to 10% by weight based on the solid content of the toner. As the aggregating agent to be used, a compound having a monovalent or higher charge is preferable. Specific examples of the compound include the above-mentioned ionic surfactants, acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid, oxalic acid, and chloride. Examples thereof include, but are not limited to, magnesium, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate, and polyaluminum chloride.

  An effective amount of the charge control agent may be used, for example, 0.1 to 5% by weight of the toner. Suitable charge control agents include, but are not limited to, alkyl pyridinium halides, bisulfates, charge control agents such as silica, and negative charge control agents such as aluminum complexes. Examples of other additives used include waxes that act as mold release agents. A preferable amount of the wax is about 5 to 20% by weight based on the solid content of the toner.

  The type of wax is not particularly limited. For example, low molecular weight polyolefins such as polyethylene, polypropylene and polybutene; silicones having a softening point; fatty acids such as oleic acid amide, erucic acid amide, ricinoleic acid amide and stearic acid amide Amides; plant waxes such as carnauba wax, rice wax, candelilla wax, tree wax, jojoba oil; animal waxes such as beeswax; montan wax, ozokerite, ceresin, paraffin wax, microcrystalline wax, Fischer-Tropsch wax And mineral waxes such as petroleum waxes; ester waxes of higher fatty acids such as stearyl stearate and behenyl behenate and higher alcohols.

  Examples of inorganic fine particles to be wet-added include silica, alumina, titania, calcium carbonate, magnesium carbonate, and tricalcium phosphate, all of which are usually used as external additives on the toner surface, such as ionic surfactants and polymers. It can be dispersed in water with an acid or a polymer base and added wet.

[Wastewater treatment method]
The waste water treatment method of the present embodiment will be described with reference to the drawings.

  From the toner manufacturing process, a coloring agent such as a surfactant aqueous solution, a pigment dispersion, and a wax dispersion which are no longer necessary in the manufacturing process or generated during equipment maintenance in the manufacturing process are discharged.

  FIG. 1 shows a wastewater treatment method according to the embodiment, and FIG. 2 shows a conventional wastewater treatment method.

  In FIG. 1, wastewater containing at least a coloring component is first subjected to a coagulation sedimentation process or a pressure levitation process. Hereinafter, the coloring component removal process from the wastewater will be described by taking the coagulation sedimentation process as an example.

  In the coagulation sedimentation treatment, first, ferric chloride, which is an inorganic coagulant, is added to the wastewater in the reaction tank to generate floc. This floc mainly contains pigments, waxes and the like as coloring components. Next, in the flocculation tank, a polymer flocculant is added, and flocs generated with the inorganic flocculant grow. Finally, the precipitated floc is removed in the settling tank. In this coagulation sedimentation treatment, pigments, waxes, and the like are removed. However, when the solid content concentration of the wastewater is high, the coloring components cannot be completely removed.

  Further, the pressure levitation process is performed as follows. First, ferric chloride, which is an inorganic flocculant, is added to the wastewater in the reaction tank to produce flocs, and then a polymer flocculant is added to grow the flocs produced by the inorganic flocculants. Thereafter, in the pressurized levitation tank, the floc is adsorbed on the surface of the bubbles introduced into the tank, and the floc floating on the surface of the tank is removed.

  Next, after removing the flocs, an accelerated oxidation treatment is performed to completely remove the coloring components.

  After each of these treatments, they are released into rivers. On the other hand, the precipitate (floc) after coagulation sedimentation is processed as sludge of industrial waste through a sludge dewatering process.

  As the flocculant used in this wastewater treatment facility, an inorganic flocculant and an organic flocculant are used. As the inorganic flocculant, for example, aluminum sulfate, ferric chloride, polyaluminum chloride and the like are used. The amount of the inorganic flocculant added is about 0.005 to 1 part, more preferably about 0.01 to 0.5 part with respect to 100 parts by weight of the waste water. However, the inorganic flocculant is not necessarily limited to these. Furthermore, for growing flocs, for example, an acrylamide anionic flocculant can be used as the polymer flocculant. As addition amount, it is about 0.00001-0.001 part with respect to 100 weight part of waste_water | drain. The polymer flocculant is not necessarily limited to acrylamide anionic flocculants, and other anionic flocculants, cationic flocculants, and nonionic flocculants can be used. Moreover, you may use combining these.

  Further, the accelerated oxidation treatment method used in the present invention is a method of decomposing organic matter by generating hydroxy radicals having strong oxidizing power by combining ozone and hydrogen peroxide and further combining an oxidizing agent such as ultraviolet rays. By using it in the waste water treatment process, it is an effective method for removing colored components contained in the waste water.

  That is, as a result of intensive studies, the present inventor can remove colored components in wastewater containing colored components by accelerated oxidation treatment, thereby removing the colored components present in water. Since the amount of the inorganic flocculant required for precipitation or pressure levitation treatment can be reduced, the inventors have found that the object of the present invention is achieved and have completed the present invention.

  The accelerated oxidation treatment used in this embodiment is a method of oxidatively decomposing organic substances by the action of hydroxy radicals. The generation of the hydroxy radical can be obtained by reacting ozone with hydrogen peroxide, but is not limited to this method. In addition, content of the coloring component contained in waste_water | drain is 0.00001 part-0.04 part with respect to 100 parts of waste_water | drain.

  The coloration of the above-mentioned wastewater is measured with a chromaticity meter (Nippon Denshoku Industries Co., Ltd., Water Analyzer 2000N, a water color and turbidity measuring device). (Based on the method), when the coloring degree by this chromaticity meter is in the range of 100 to 1000, ozone is 0.00001 to 0.0001 parts with respect to 1000 parts of waste water, and hydrogen peroxide is a 30% by weight solution. It is preferable to use 0.01 to 0.1 parts by weight with respect to 1000 parts of drainage. In addition, the coloring measurement by a chromaticity meter is performed as follows. Create a chromaticity calibration curve using the chromaticity standard solution. Next, the coloration degree of the waste water is measured, and the chromaticity of the waste water is obtained from the calibration curve.

  In the conventional wastewater treatment of FIG. 2, only the coagulation sedimentation treatment or the pressure levitation treatment is performed, and then discharged into a river or the like. On the other hand, the precipitate (sludge) after the coagulation sedimentation is processed as sludge of industrial waste through a sludge dehydration process.

  Next, the present invention will be described more specifically with reference to Examples and Comparative Examples.

  Hereinafter, production examples of the electrostatic charge developing toner used in this example and the comparative example will be shown.

[Toner Production Example 1]
<First step>
--Preparation of dispersion (1)-
Styrene 320 parts by weight n-butyl acrylate 80 parts by weight Acrylic acid 10 parts by weight Dodecanethiol 10 parts by weight

  434 parts by weight of this solution, 6 parts by weight of a nonionic surfactant (manufactured by Sanyo Chemical Co., Ltd., Nonipol 400) and 10 parts by weight of an anionic surfactant (manufactured by Daiichi Pharmaceutical Co., Ltd., Neogen R) are added to 550 ion-exchanged water. The solution dissolved in parts by weight was placed in a flask to disperse and emulsify, and 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added while slowly stirring and mixing for 10 minutes. Then, after fully replacing the inside of the flask with nitrogen, the system was heated with an oil bath until the temperature reached 70 ° C. while stirring, and emulsion polymerization was continued as it was for 5 hours to obtain a resin fine particle dispersion A-1.

The latex obtained with the resin fine particle dispersion A-1 was 155 nm when the volume average particle diameter (D ₅₀ ) of the resin fine particles was measured with a laser diffraction particle size distribution analyzer (LA-700, manufactured by Horiba, Ltd.). When the glass transition point of the resin was measured at a heating rate of 10 ° C./min using a differential scanning calorimeter (Shimadzu Seisakusho Co., Ltd., DSC-50), it was 54 ° C., and a molecular weight measuring instrument (manufactured by Tosoh Corporation, HLC- 8020), and the weight average molecular weight (polystyrene conversion) was measured using THF as a solvent.

-Preparation of release agent dispersion (1)-
50 parts by weight of paraffin wax (manufactured by Nippon Seiwa Co., Ltd .: HNP0190, melting point 85 ° C.)
Cationic surfactant ... 5 parts by weight (manufactured by Kao Corporation: Sanisol B50)
Ion-exchanged water ... 200 parts by weight

  The above was heated to 95 ° C. and dispersed using a homogenizer (IKA: Ultra Turrax T50), and then dispersed with a pressure discharge homogenizer to disperse a release agent having an average particle size of 550 nm. A release agent dispersion (1) was prepared.

-Preparation of colorant dispersion (1)-
Carbon black pigment (Cabot: Regal 330) 70 parts Anionic surfactant (Wako Pure Chemical Industries) 3 parts Ion-exchanged water 400 parts

  After mixing and dissolving each of the above components, a colorant dispersion liquid in which a colorant (carbon black pigment) having an average particle diameter of 150 nm is dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax) 1) was obtained.

--Preparation of aggregated particles--
Dispersion (1) ... 200 parts by weight Colorant dispersion (1) ... 30 parts by weight Release agent dispersion (1) ... ··· 70 parts by weight Cationic surfactant ······ 1.5 parts by weight (manufactured by Kao Corporation: Sanisol B50)

The above was mixed and dispersed in a round stainless steel flask using a homogenizer (manufactured by IKA: Ultra Turrax T50), and then heated to 48 ° C. while stirring the inside of the flask in an oil bath for heating. After maintaining at 48 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles (volume: 95 cm ³ ) having an average particle diameter of about 5 μm were formed.

--Preparation of adhered particles--
Here, 60 parts by weight of the dispersion liquid (1) as the resin-containing fine particle dispersion liquid was gradually added. The volume of the resin particles contained in the dispersion (1) is (25 cm ³ ). And the temperature of the heating oil bath was raised to 50 degreeC, and was hold | maintained for 1 hour. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 5.7 μm were formed.

<Third step>
Then, after adding 3 g of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC), the stainless steel flask was sealed, and stirring was continued using a magnetic seal up to 105 ° C. Heated and held for 3 hours. After cooling, the reaction product was filtered, sufficiently washed with ion exchange water, and then dried to obtain an electrostatic charge image developing toner.

  The degree of coloration of the waste water A discharged during the production of Production Example 1 was measured with the chromaticity meter described above and was 100.

[Toner Production Example 2]
-Preparation of colorant dispersion (2)-
Carbon black pigment (Cabot: Regal 330) 140 parts Anionic surfactant (Wako Pure Chemical Industries) 3 parts Ion-exchanged water 330 parts

  After mixing and dissolving each of the above components, a colorant dispersion liquid in which a colorant (carbon black pigment) having an average particle diameter of 150 nm is dispersed using a homogenizer (manufactured by IKA, Ultra Tarrax) 2) was obtained.

--Preparation of aggregated particles--
Dispersion (1) ········ 200 parts by weight Colorant dispersion (2) ······· 30 parts by weight Release agent dispersion (1) ··· ··· 70 parts by weight Cationic surfactant ······ 1.5 parts by weight (manufactured by Kao Corporation: Sanisol B50)

The above was mixed and dispersed in a round stainless steel flask using a homogenizer (manufactured by IKA: Ultra Turrax T50), and then heated to 48 ° C. while stirring the inside of the flask in an oil bath for heating. After maintaining at 48 ° C. for 30 minutes, observation with an optical microscope confirmed that aggregated particles (volume: 95 cm ³ ) having an average particle diameter of about 5 μm were formed.

--Preparation of adhered particles--
Here, 60 parts by weight of the dispersion liquid (2) as the resin-containing fine particle dispersion liquid was gradually added. The volume of the resin particles contained in the dispersion (1) is (25 cm ³ ). And the temperature of the heating oil bath was raised to 50 degreeC, and was hold | maintained for 1 hour. When observed with an optical microscope, it was confirmed that adhered particles having an average particle diameter of about 5.9 μm were formed.

<Third step>
Thereafter, after adding 3 parts by weight of an anionic surfactant (Daiichi Kogyo Seiyaku Co., Ltd .: Neogen SC), the stainless steel flask was sealed, and stirring was continued using a magnetic seal. Heated to 0 ° C. and held for 3 hours. After cooling, the reaction product was filtered, sufficiently washed with ion exchange water, and then dried to obtain an electrostatic charge image developing toner.

  The degree of coloration of the waste water B discharged during the production of Production Example 2 was measured with the above-described chromaticity meter, and was chromaticity 1000.

[Composition of drainage A]
The wastewater A is wastewater discharged by the production of Production Example 1 and includes at least a pigment, a wax, an emulsion, and a surfactant. The main composition of the drainage A is shown below.

Anionic surfactant ("Neogen SC", manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 0.08 parts by weight Latex polymer: 0.4 parts by weight Colorant: 0.016 parts by weight Wax ("Polywax 725" Toyo Petrolite Co., Ltd.): 0.12 parts by weight Water: 999.5 parts by weight

[Composition of drainage B]
The waste water B is waste water discharged by the production of Production Example 2 and includes waste water containing pigments, waxes, emulsions, and surfactants. The main composition of the waste water B is shown below.

Anionic surfactant (“Neogen SC” manufactured by Daiichi Kogyo Seiyaku Co., Ltd.): 0.09 parts by weight Latex polymer: 0.5 parts by weight Colorant: 0.12 parts by weight Wax (“Polywax 725” Toyo Petrolite Co., Ltd.): 0.22 parts by weight Water: 999.1 parts by weight

Example 1
Wastewater A Treatable substance to be treated A solid content concentration of 0.5 wt%, wastewater A (chromaticity 300), 1000 parts, was treated using the wastewater treatment facility shown in FIG. For the coagulation sedimentation treatment, 1 part by weight of inorganic flocculant (ferric chloride) is used for 1000 parts of waste water A, and polymer flocculant (acrylamide polymer flocculant: Hymolock SS-100: manufactured by Hymo Co.) is used for waste water A1000. 0.001 part by weight was added to the part, and the wastewater treatment facility having a coagulation sedimentation tank of 18 m ³ was processed in a batch system. The accelerated oxidation treatment was performed in a 100 m ³ treatment tank in 3 hours. The conditions for the accelerated oxidation treatment were 0.00002 parts by weight with respect to the ozone amount, 1000 parts of waste water A, and 0.01 parts by weight with respect to 1000 parts of waste water A (with 30 wt% solution). As a result, the amount of sludge generated was 6 parts, the treated waste water was not colored, it was transparent with “chromaticity 1” by the above-mentioned chromaticity meter, and there was no problem with the processability.

(Example 2)
Drainage B processable substance Wastewater B (chromaticity 500) having a solid content concentration of 0.9 wt%, 1000 parts, was treated in the same manner as in Example 1 using the wastewater treatment facility shown in FIG. At this time, the inorganic flocculant (ferric chloride) is 2 parts by weight with respect to 1000 parts of waste water B, and the polymer flocculant (acrylamide polymer flocculant: Hymorlock SS-100) is 0.002 with respect to 1000 parts of waste water B. A part by weight was added, and the wastewater treatment facility having an 18 m ³ coagulation sedimentation tank was used for batch processing. The accelerated oxidation treatment was carried out in a treatment tank of 100 m ³ for 5 hours. The conditions of the accelerated oxidation treatment were 0.00005 parts by weight with respect to 1000 parts of ozone wastewater A and 0.04 parts by weight with respect to 1000 parts of hydrogen peroxide (in a 30 wt% solution) wastewater A. As a result, the amount of sludge generated was 10 parts by weight, the treated waste water was not colored, it was transparent with “chromaticity 5” by the above-mentioned chromaticity meter, and there was no problem with the processability.

Example 3
Disposal of wastewater C 1000 parts of wastewater C having a solid content concentration of 0.5 wt% and a concentration of 5 wt% of wastewater C was processed using the wastewater treatment facility shown in FIG. . In the pressure flotation treatment, 5% by weight of inorganic flocculant (ferric chloride) is drained with respect to 1000 parts of drainage C, and polymer flocculant (acrylamide polymer flocculant: Hymolock SS-100: manufactured by Hymo Co.) is drained. 0.01 weight part was added with respect to 1000 parts of C, and it processed by the batch type with the waste water treatment facility which has a pressurized floating tank of 18m < ³ >. The accelerated oxidation treatment was carried out in a treatment tank of 100 m ³ for 5 hours. The conditions of the accelerated oxidation treatment were 0.0001 parts by weight with respect to 1000 parts of ozone waste water and 0.09 parts by weight with respect to 1000 parts of waste water (with a 30 wt% hydrogen peroxide solution). As a result, the amount of sludge generated was 55 parts, the treated waste water was not colored, it was transparent with “chromaticity 1” by the above-mentioned chromaticity meter, and there was no problem with the processability.

(Comparative Example 1)
Disposal of wastewater C 1000 parts of wastewater C (chromaticity 900) having a solid content concentration of 5 wt% was treated using the wastewater treatment facility of FIG. At this time, 45 parts by weight of inorganic flocculant (ferric chloride) with respect to 1000 parts of waste water C, and 0.2% of polymer flocculant (acrylamide polymer flocculant: Hymorok SS-100) with respect to 1000 parts of waste water C A part by weight was added, and the wastewater treatment facility having an 18 m ³ coagulation sedimentation tank was used for batch processing. The accelerated oxidation treatment was not performed. As a result, it takes 12 hours to treat the waste water, the amount of sludge generated is 95 parts by weight, and about 1.7 times as much sludge as in Example 3 is generated. The processability was bad.

(Comparative Example 2)
The process of the substance to be treated solid concentration 0.5 wt% of the waste water A (chromaticity 300) 1000 parts by weight of the waste water A, it was treated with wastewater treatment facility of FIG. At this time, the inorganic flocculant (ferric chloride) is 5 parts by weight with respect to 1000 parts of waste water A, and the polymer flocculant (acrylamide polymer flocculant: Hymorlock SS-100) is 0.002 with respect to 1000 parts of waste water A. A part by weight was added, and the wastewater treatment facility having an 18 m ³ coagulation sedimentation tank was used for batch processing. The accelerated oxidation treatment was not performed. As a result, the wastewater treatment requires 10 hours, the amount of sludge generated is 10 parts by weight, and about 1.7 times as much sludge as in Example 1 is generated. The processability was bad. It took 7 hours to treat 100 m ³ of waste water. As a result, the amount of sludge generated was 185 g / L, and about 2.5 times as much sludge was generated as in Example 2. Further, even after the coagulation sedimentation treatment, the waste water was still colored with pigments and the like, and the chromaticity was “chromaticity 100”, and the processability was poor.

  The wastewater treatment method of the present invention is particularly useful for wastewater treatment discharged during the production of electrostatic charge developing toner, but is also useful for colored industrial wastewater treatment having substances having different organic and inorganic characteristics.

It is a figure explaining the waste water treatment method concerning an embodiment. It is a figure explaining the conventional waste water treatment method.

Claims (2)

A wastewater treatment method for treating wastewater containing at least a coloring component generated from a production process of an electrostatic charge image developing toner,
A wastewater treatment method comprising a step of removing a coloring component generated from the production step by organic matter oxidation treatment. The waste water treatment method according to claim 1,
A method for treating waste water, wherein the step of removing the coloring component comprises an accelerated oxidation treatment.

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