JP2008279402A - Water treatment apparatus and water treatment method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a water treatment apparatus capable of reducing the usage of a flocculating agent and the amount of generation of sludge in treatment of water to be treated at least containing a colored component. <P>SOLUTION: The treatment apparatus treats water to be treated containing at least the colored component as a treatment target, and includes: a calcium salt addition means for adding calcium salts to the water to be treated; a mixing tank for mixing the water to be treated with the calcium salts; and a separation means for separating a solid content in the mixed liquid from a water content. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a water treatment apparatus and a water treatment method.

  For example, in a manufacturing process of an aqueous dispersion in a manufacturing factory such as a water-based paint and an electrophotographic toner (hereinafter sometimes simply referred to as “toner”), water containing a coloring component or the like is generated. In addition to pigments and dyes, which are coloring components, these waters contain dispersants such as surfactants to increase the dispersibility of pigments, etc. The amount is large and cannot be discharged into rivers or sewers in this state. Therefore, these waters are reused after being processed at a water treatment facility in the factory or discharged to the outside.

  In particular, in recent years, various chemical toner production methods such as suspension polymerization method and dissolution suspension method have been developed and implemented as a method for producing electrophotographic toner, including toner by emulsion polymerization method instead of conventional kneading and pulverization method. Has been. For example, in the emulsion polymerization method, a resin dispersion formed by emulsion polymerization of a polymerizable monomer of a binder resin, a colorant, a release agent, and a charge control agent as necessary in the presence of a surfactant, While stirring and mixing in an aqueous solvent, the toner particles are colored resin particles having a predetermined particle size, particle size distribution, shape and structure by agglomeration and heat fusion, and in this process, an aqueous surfactant solution, Water containing solids such as a colorant dispersion, a release agent dispersion, an aqueous emulsion solution, and apparatus washing water is generated.

  Usually, as a general water treatment, a coagulation sedimentation treatment is often used. Coagulation and sedimentation treatment is the most common in the field of water treatment, as described on pages 141 to 153 of the technology and legal water quality edition (supervised by the Ministry of International Trade and Industry, Environmental Location Bureau, published in 2001). It is a solid-liquid separation operation used in Japan and is widely used. The coagulation sedimentation treatment is a treatment method in which flocs (coarse particles generated by aggregation) are generated by adding a flocculant to raw water, and the flocs are precipitated due to the difference in specific gravity between water and flocs to perform solid-liquid separation. The flocs thus separated as solids are treated as industrial waste sludge, and the water from which the solids have been separated has a reduced chemical oxygen demand and is reused or discharged into rivers and sewers. The sludge after the solid-liquid separation is often dehydrated as it is with a pressure filtration dehydrator. Pressure filtration and dehydration equipment is the most common in the field of water treatment, as described in page 182 of 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). It is a dehydration device used in general.

  In Patent Document 1, in a wastewater treatment method for solid-liquid separation of organic pollutant-containing wastewater, a wastewater treatment method that facilitates final treatment of sludge by returning a part of the generated sludge to the treated raw water side and circulating it. Is disclosed. Patent Document 2 discloses a method of adding a flocculant to waste water and using a filter cloth as a method for solid-liquid separation of washing waste water such as toning of water-based paints and machinery for painting. Patent Document 3 discloses a wastewater treatment method that reduces the amount of flocculant used and the amount of sludge generated by separating a drainage line in a wastewater treatment method containing a surfactant. Patent Document 4 discloses a wastewater treatment method that reduces the amount of flocculant used and the amount of sludge generated by having a step of ionizing a silica component in a wastewater treatment method containing silica. In patent document 5, the method of removing the nitrogen content in waste_water | drain is provided in the processing method of the waste_water | drain containing a nitrogen component by providing the process of removing a nitrogen component by anaerobic treatment. Patent Document 6 discloses a wastewater treatment method including a step of removing a colored component by organic matter oxidation treatment in a wastewater treatment method containing a colored component. Patent Document 7 discloses a wastewater treatment method for reducing the amount of sludge generated by having a coagulation treatment step and a concentration treatment step in a wastewater treatment method containing a surfactant. Patent Document 8 discloses a wastewater treatment method that reduces sludge generation by having a different wastewater treatment method in accordance with the solid content concentration in a wastewater treatment method containing solid content. Patent Document 9 discloses a wastewater treatment method for reducing the amount of flocculant used and the amount of sludge generated by using a polysilica iron flocculant in a wastewater treatment method containing a surfactant, a colorant, and silica. Yes. Patent Document 10 discloses a wastewater treatment method for reducing the amount of flocculant used and the amount of sludge generated by adjusting the surface potential of silica in a wastewater treatment method containing a surfactant, a colorant, and silica. ing.

JP-A-7-136408 JP-A-8-182992 JP 2004-351379 A JP-A-2005-205323 JP 2006-791 A Japanese Patent Laid-Open No. 2006-7016 JP 2006-75751 A JP 2005-181549 A JP 2006-346610 A Japanese Patent Laid-Open No. 2007-29802

  The present invention is a water treatment apparatus and a water treatment method capable of reducing the amount of flocculant used and the amount of sludge generated in the treatment of water to be treated containing at least a coloring component.

  The present invention is intended to treat water to be treated containing at least a coloring component, a calcium salt adding means for adding a calcium salt to the water to be treated, and a mixing tank for mixing the water to be treated and the calcium salt A water treatment device having a separating means for separating the solid content and water in the mixed liquid.

  Further, the present invention is directed to treating water to be treated containing at least a coloring component, a reaction tank for performing a coagulation reaction of the water to be treated, a floc formed from the coagulated aggregate and a separation liquid. Floc separating means for separating, calcium salt adding means for adding calcium salt to the floc, a mixing tank for mixing the floc and the calcium salt, and solid content and moisture in the mixed liquid mixture And a separation means for separating.

  Further, the present invention is intended to treat water to be treated containing at least a coloring component, add a calcium salt to the water to be treated and mix, and separate the solid content and moisture in the mixed liquid mixture. And a separation process.

  Furthermore, the present invention is intended to treat water to be treated containing at least a coloring component, add a flocculant to the water to be treated, and perform a flocculence reaction. A floc forming step for forming, a floc separating step for separating the floc and the separation liquid, a mixing step for adding calcium salt to the floc and mixing, and a solid content and moisture in the mixed liquid mixture And a separation step for separating.

  According to claim 1 of the present invention, in the water treatment apparatus that treats the water to be treated containing at least a coloring component, the amount of the flocculant used and the amount of sludge generated can be reduced.

  According to the second aspect of the present invention, in the water treatment apparatus that treats the water to be treated containing at least a coloring component, the amount of the flocculant used and the amount of sludge generated can be reduced.

  According to claim 3 of the present invention, the amount of flocculant used and the amount of sludge generated can be reduced in a water treatment method for treating water to be treated containing at least a coloring component.

  According to claim 4 of the present invention, the amount of flocculant used and the amount of sludge generated can be reduced in a water treatment method for treating water to be treated containing at least a coloring component.

  Embodiments of the present invention will be described below. This embodiment is an example for carrying out the present invention, and the present invention is not limited to this embodiment. Here, a water treatment apparatus and a water treatment method according to an embodiment of the present invention will be described using water discharged from the electrophotographic toner manufacturing process as an example of water to be treated.

  For example, from the toner manufacturing process in the electrophotographic toner manufacturing factory by the chemical toner manufacturing method, that is, the wet manufacturing method, it becomes unnecessary in the manufacturing process, or the surfactant aqueous solution generated in the inspection of the manufacturing process, the coloring agent dispersion, etc. Water containing surfactants and coloring components such as liquid, release agent dispersion, emulsion dispersion, and apparatus cleaning water is discharged.

  According to the results examined by the present inventors, the total amount of water in the surfactant aqueous solution, the colorant dispersion, the release agent dispersion, the emulsion aqueous solution, the silica dispersion, and the like discharged from the toner production process. When water having a low solid content occupying 30 to 70% by weight, for example, water containing an aqueous surfactant solution and water having a high solid content are mixed, the coagulation precipitation treatment is performed by the action of the surfactant. In addition, the sedimentation time becomes longer, and the amount of inorganic flocculant used for agglomeration and precipitation, such as ferric chloride, increases, resulting in an increase in the amount of agglomerated sediment and finally industrial disposal. A large amount of sludge to be processed as waste is generated. In addition, since the aggregated precipitate after the aggregation precipitation treatment generated from these waters has a low aggregation strength, the size of the aggregated precipitate is reduced due to the strong shearing force applied by the pump used when the liquid is fed to the concentrator. As a result, it becomes smaller (for example, less than 1 mm in diameter), and as a result, sufficient sludge dewatering treatment cannot be performed, and sludge containing a larger amount of moisture than necessary is generated. In particular, the aggregation precipitate of water containing a large amount of silica dispersion has a mechanism that is not well understood but tends to have a low aggregation strength. Therefore, this phenomenon is particularly remarkable in water containing a large amount of silica dispersion.

  Therefore, as a result of intensive studies, the present inventors have conducted a coagulation sediment separation step that separates the coagulated sediment after the coagulation sedimentation treatment and the separation liquid in the treatment of water containing a coloring component, which is generated from the toner production process. Calculating sludge efficiently by adding and mixing calcium salt to the water to be treated containing the generated aggregated precipitate (floc), and separating the solids and moisture in the mixed liquid It has been found that the amount of flocculant used and the amount of sludge generated can be reduced. This is because the calcium salt is suppressed from reducing the size of the aggregated precipitate (for example, about 1 mm to 5 mm in diameter), can prevent clogging of the filter cloth and the like in the dehydrator and the like, and can perform sufficient sludge dehydration treatment. Since it can be performed, sludge with less water content can be obtained, and the amount of sludge generated can be reduced. As a result, it is not necessary to add more flocculant than necessary, and the amount of flocculant used can be reduced.

  FIG. 1 shows an outline of an example of a water treatment apparatus for performing water treatment according to this embodiment. The water treatment apparatus 1 which is an example of the water treatment apparatus according to the present embodiment includes a raw water tank 10, a reaction tank 12, a coagulation tank 14, a coagulation sedimentation tank 16 which is a floc separation means, a biological treatment tank 18, a post-precipitation tank 20, An inlet and an outlet of the sand filtration device 22 and the activated carbon filtration adsorption device 24 are connected in series via piping or the like. Further, the inlet of the sludge slurry storage tank 26 is connected to the outlet of the lower part of the coagulation sedimentation tank 16 and the outlet of the lower part of the post sedimentation tank 20 through a pipe or the like, and the sludge slurry storage tank 26, the mixing tank 28, and the sludge reaction tank 30. The inlet and the outlet are connected in series via piping or the like. The inlet of the sludge concentrator 32, which is a separation means, is connected to the outlet of the lower part of the sludge reaction tank 30, and the inlet of the dehydrator 34 is connected to the outlet of the sludge concentrator 32 via a pipe or the like. Further, a calcium salt tank 36 as a calcium salt addition means is connected to the mixing tank 28 via a valve 38.

  The operation of the water treatment apparatus and the water treatment method according to this embodiment will be described with reference to FIG.

  The water discharged from the toner manufacturing process is first subjected to a coagulation sedimentation process. In the coagulation sedimentation treatment, a reaction step of adding a coagulant to the raw water that is the water to be treated and a coagulation reaction in the reaction tank 12 and a floc that forms a floc from the coagulation reaction in the reaction step in the coagulation tank 14 are performed. A formation step and a floc separation step of separating the floc and the separation liquid in the coagulation sedimentation tank 16. Note that a solid-liquid separation process such as a pressure levitation process may be performed instead of the coagulation sedimentation process.

  First, after the raw water is temporarily stored in the raw water tank 10, a flocculant is added by a pump or the like while being rapidly stirred in the reaction tank 12 by a stirring means such as a stirring blade, and agglomeration reaction is performed (reaction process). Thereafter, the reaction solution subjected to the aggregation reaction is sent to the aggregation tank 14.

  As the flocculant used in this reaction step, general inorganic flocculants and organic flocculants can be used. As the inorganic flocculant, for example, aluminum sulfate, ferric chloride, polyaluminum chloride, polysilica iron flocculant and the like are used, and ferric chloride is used because it is inexpensive and has good aggregation properties. It is preferable to be used.

  Examples of the organic flocculant include anionic polymer flocculants such as polyacrylamide and polyacrylate soda; polyacrylamide, polyacrylate, polymethacrylate, polyamine, and polydicyandiamide. Cationic polymer flocculants such as polyamides; Nonionic polymer flocculants such as polyacrylamides and polyethylene oxides; Amphoteric polymer flocculants such as dimethylaminoethyl acrylate can be used. It is more preferable to use a polyacrylamide anionic polymer flocculant because of its good aggregation properties. Further, as the flocculant, two or more flocculants selected from the above-mentioned inorganic flocculants and organic flocculants may be used in combination, and ferric chloride is used as the inorganic flocculant. It is preferable to use a polyacrylamide-based anionic polymer flocculant in combination as an organic flocculant for growing the organic flocculant.

  When the inorganic flocculant is used, the amount added is preferably in the range of 500 mg / L to 5000 mg / L with respect to the water to be treated, and in the range of 1000 mg / L to 3000 mg / L. More preferably.

  In addition, the amount of addition in the case of using an organic flocculant is preferably a concentration in the range of 0.5 mg / L to 5 mg / L with respect to the water to be treated, preferably 1 mg / L to 3 mg / L. It is more preferable that the concentration be in the range.

  The pH of the reaction solution during the agglutination reaction is preferably in the range of 6 to 8 and more preferably in the range of 6.5 to 7.5 from the viewpoint of the aggregation effect.

  In the reaction step, the agglomeration reaction is performed by rapid stirring by a stirring means such as a stirring blade. The stirring speed is preferably in the range of 100 rpm to 500 rpm. If the stirring speed is less than 100 rpm, the agglomeration reaction may not be sufficiently performed and fine particles may not be reduced. If the stirring speed is greater than 500 rpm, the aggregate once formed may become fine again.

  Next, in the flocculation tank 14, the reaction liquid transferred from the reaction tank 12 is slowly stirred by stirring means such as a stirring blade to form a floc in which suspended substances in water are aggregated (floc formation). Process). This floc mainly contains pigments, release agents, toner particles and the like used in toner production. The floc grows with slow agitation. The solid content concentration of the floc suspension (treatment liquid) obtained at this time is about 0.5% to 1.5%. In addition, the reaction process and the flock formation process may be performed in one tank using the tank in which the reaction tank 12 and the aggregation tank 14 are integrated.

  The floc is grown by stirring with a stirring means such as a stirring blade in the floc forming step. The stirring speed is preferably in the range of 60 rpm to 500 rpm, more preferably in the range of 100 rpm to 300 rpm. When the stirring speed is less than 60 rpm, flocs are not sufficiently formed and fine particles may not be reduced. When the stirring speed is greater than 500 rpm, flocs once formed may become fine again.

  Next, the processing liquid that has floc formed in the coagulation tank 14 is sent to the coagulation sedimentation tank 16. In the floc forming step, the reaction liquid is normally continuously flowed into the coagulation tank 14, and the floc formed processing liquid is continuously sent to the coagulation sedimentation tank 16. At this time, the residence time in the coagulation tank 14 is preferably in the range of 5 minutes to 20 minutes, and more preferably in the range of 10 minutes to 15 minutes. If the residence time is less than 5 minutes, flocs are not sufficiently formed, and fine particles may not be reduced. If the residence time is more than 20 minutes, the processing efficiency may be reduced. Further, the water coagulation treatment may be performed in a batch manner in the coagulation tank 14. In this case, the treatment time is preferably in the range of 5 minutes to 15 minutes, and more preferably in the range of 5 minutes to 10 minutes.

  The temperature of water to be treated in the coagulation step is usually in the range of 10 ° C. to 30 ° C., and preferably in the range of 15 ° C. to 25 ° C.

  The processing liquid sent to the coagulation sedimentation tank 16 is separated into a sediment (sludge slurry) in which flocs are concentrated and a separation liquid by natural sedimentation separation in the coagulation sedimentation tank 16 (floc separation step). In the floc separation step, a pressure levitation process or the like may be performed instead of the coagulation sedimentation process, but it is preferable to perform at least one of the coagulation sedimentation process and the pressure levitation process in terms of the amount of sludge generated. . The pressurized levitation treatment is a water treatment method that utilizes the property that air dissolved in a pressurized state is released as fine bubbles when the pressurized water is depressurized. Pressurized water is injected into the pressurized levitation tank. This is a treatment method in which floating substances in water are attached to the generated fine bubbles and floated and separated.

  The separated liquid separated from the sludge slurry in the coagulation sedimentation tank 16 is sent to the biological treatment tank 18 for biological treatment, and dissolved organic matter is removed. In the biological treatment tank 18, dissolved organic substances are decomposed by bacteria or the like that live in the activated sludge, and in the subsequent post-precipitation tank 20, they are separated into activated sludge and supernatant water by natural sedimentation. The supernatant water obtained in the post-precipitation tank 20 was subjected to adsorption treatment of dissolved chemical substances and dissolved organic substances that could not be treated in the biological treatment process by the activated carbon filtration adsorption device 24 after removing the remaining solids by the sand filtration device 22. Later, it is reused or released into rivers.

  On the other hand, the sludge slurry separated from the separated liquid in the coagulation sedimentation tank 16 and the sludge slurry obtained in the post-precipitation tank 20 are temporarily stored in the sludge slurry storage tank 26 by a pump or the like and then sent to the mixing tank 28. To be liquidated. In the mixing tank 28, calcium salt is added to the sludge slurry from the calcium salt tank 36 by a pump or the like while being rapidly stirred by stirring means such as a stirring blade (mixing step). Thereafter, the calcium salt is added, and the mixed liquid is sent to the sludge reaction tank 30 and agglomeration reaction is performed (sludge reaction step). Thereafter, the mixed liquid subjected to the coagulation reaction is sent to the sludge concentrator 32. In addition, the mixing process and the sludge reaction process may be performed in one tank using the tank in which the mixing tank 28 and the sludge reaction tank 30 are integrated.

  As the flocculant used in this mixing step, inorganic calcium salts such as calcium carbonate, calcium chloride, and calcium phosphate can be used, and calcium carbonate is preferable from the viewpoint of the safety of treated water. The amount of calcium salt added is preferably in the range of 10 mg / L or more and 5000 mg / L or less, more preferably in the range of 50 mg / L or more and 1000 mg / L or less with respect to the sludge slurry to be treated. . If the amount added is less than 10 mg / L, the moisture content of the generated sludge may be low, and if it exceeds 5000 mg / L, the amount of generated sludge increases and separation in the next step is difficult. There is a case. As calcium carbonate, for example, one produced by blowing carbon dioxide into calcium hydroxide may be used.

  In the mixing step and the reaction step, mixing and agglomeration reaction are performed by rapidly stirring with a stirring means such as a stirring blade. The stirring speed is preferably in the range of 100 rpm to 500 rpm. If the stirring speed is less than 100 rpm, the agglomeration reaction may not be sufficiently performed and fine particles may not be reduced. If the stirring speed is greater than 500 rpm, the aggregate once formed may become fine again.

  Next, in the sludge concentrating device 32, the mixed liquid is separated into a sludge separation liquid and a solid content (a separation step). In the sludge concentration apparatus 32, it concentrates by natural sedimentation over about 6 hours or more and 12 hours or less, for example. The solid content concentration before solid concentration is about 0.5 wt% or more and 1.5 wt% or less. Moreover, the solid content concentration of the solid content after the concentration is about 2.0 wt% or more and 4.0 wt% or less. The solid content after the concentration is dehydrated by the dehydrator 34 (dehydration process), and is then processed as industrial waste sludge. In addition, the solid content concentration of the sludge cake after dehydration is about 30 wt% or more and 60 wt% or less. The sludge separation liquid, which is the filtrate generated in the sludge concentrator 32 and the dehydrator 34, is transferred to the raw water tank 10 for storing the water generated in the toner manufacturing process, mixed with new raw water, and then It may be treated with a water treatment process.

  Examples of the dehydrating device 34 include a pressure filter such as a pressure leaf filter and a pressure nutsche, a filter press, a pressure levitation machine, a vacuum filter, and the like. Usually, a filter press is used. According to this embodiment, clogging of the filter cloth and the like in the dehydrating device 34 such as a filter press can be prevented. In addition, a centrifuge device is used before the dehydration process from the viewpoint of reducing the amount of sludge generated, reducing the processing time, reducing the amount of flocculant, and maintainability of the device. It may be dehydrated by centrifugal concentration.

  In the conventional water treatment method, as shown in FIG. 5, in the reaction tank 12 of the water treatment device 5, the raw water discharged from the toner production process or the like is treated using a flocculant such as ferric chloride. Further, if necessary, a treatment using a polymer flocculant is performed. Subsequently, the aggregated sediment tank 16 separates the aggregated sediment (sludge slurry) and the separated liquid. However, the generated aggregated precipitate has a weak aggregation strength, and is strong when the liquid is fed to the sludge concentrator 32 and the dewatering unit 34. Because of the shearing force, the size of the aggregated precipitate is reduced, and as a result, sufficient sludge dewatering treatment cannot be performed, and sludge containing a larger amount of moisture than necessary is generated. In addition, when a large amount of an inorganic flocculant such as ferric chloride is added at the time of coagulation sedimentation to increase the cohesive strength of the coagulation sediment, the amount of the coagulation sediment increases, resulting in industrial waste. As a result, a large amount of sludge is processed. As described above, in the conventional method, particularly for water containing silica or the like, the amount of the flocculant used for coagulating and precipitating and increasing the strength of the sludge increases, and as a result, a large amount of sludge is generated. . Compared to this, in the water treatment method according to the present embodiment, by mixing a calcium salt such as calcium carbonate before dewatering of the sludge slurry, the sludge further aggregates and becomes larger, and the dewatering treatment of the sludge is efficiently performed. This can be performed and sludge containing a larger amount of moisture than necessary is not generated, so that the amount of sludge generated can be reduced.

  FIG. 2 shows an outline of another example of the water treatment apparatus for performing the water treatment according to the present embodiment. The water treatment apparatus 2 shown in FIG. 2 includes a surface tension measuring device 40 that is a surface tension measuring means in addition to the configuration of FIG. The surface tension measuring device 40 is connected to the raw water inflow tank to the raw water tank 10 and installed. The installation position of the surface tension measuring device 40 may be before the coagulation sedimentation treatment, that is, before the reaction tank 12, and may be connected to a pipe or the like connecting the raw water tank 10 and the reaction tank 12.

  According to the study of the present inventors, when water containing a surfactant is mixed with other water, for example, water containing a colorant dispersion, a release agent dispersion, a silica dispersion, an aqueous emulsion solution, or the like. Since the dispersion state of the pigment and the like is more stable due to the action of the surfactant, the settling time in the coagulation sedimentation treatment becomes longer, and the inorganic coagulant used for coagulation precipitation, for example, ferric chloride As a result, the amount of addition 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 considered to be because a certain amount of ferric chloride used as an inorganic flocculant has a charge neutralization reaction with a surfactant contained in water and inhibits the action as a flocculant. .

  If the amount of the surfactant contained in the water can be monitored and grasped, it is not necessary to add an excessive coagulant, and the amount of sludge generated in the coagulation sedimentation process can be reduced. Therefore, in this embodiment, paying attention to the fact that there is a certain correlation between the amount of surfactant in water and the surface tension value, a surface tension measuring device is provided before water treatment, and the surface tension of water containing surfactant in advance. By measuring the value and controlling the amount of coagulant based on the measured surface tension value, the amount of coagulant required for coagulation sedimentation can be reduced, and the amount of floc generated in the coagulation sedimentation process is reduced, resulting in the amount of generated sludge. Can be reduced.

  The operation of the water treatment apparatus and the water treatment method according to this embodiment will be described with reference to FIG. In FIG. 2, the surface tension of the raw water containing the surfactant is measured by the surface tension measuring device 40. In the reaction tank 12, the measured surface tension value data is transmitted to a supply device such as ferric chloride as a flocculant, and the supply amount of a predetermined flocculant according to the surfactant concentration in the raw water is the reaction tank. 12 to generate a floc for solid-liquid separation. Thereafter, the treatment is performed in the same manner as the water treatment method of FIG. Thereby, the amount of flocculant used and the amount of sludge generated can be further reduced.

  At this time, for example, if the reference surface tension value is set in advance and the surface tension value of the raw water measured by the surface tension measuring device 40 is higher than the preset reference surface tension value, the amount of free surfactant is small. If the measured surface tension value is lower than the preset reference surface tension value, the amount of free surfactant is increased, so the amount of flocculant added is adjusted. It is preferable to make adjustments such as increasing. The reference surface tension value may be appropriately set according to the properties of the raw water, but may be set within a range of 40 mN / m or more and 60 mN / m or less, and usually 45 mN / m or more and 55 mN / m or less. It is preferable to set.

  FIG. 3 shows an outline of another example of the water treatment apparatus for performing the water treatment according to the present embodiment. The water treatment apparatus 3 shown in FIG. 3 includes a post reaction tank 42 in addition to the configuration of FIG. Further, a first pH detecting means 44 and a second pH detecting means 46 are provided. The post-reaction tank 42 is installed between the reaction tank 12 and the aggregation tank 14. The first pH detection means 44 is installed in the reaction tank 12 and the second pH detection means 46 is installed in the post-reaction tank 42, respectively.

  Conventionally, in the treatment of water containing a coloring component and a surfactant generated during the production of a toner, especially a coloring component and an anionic surfactant, the removal of the coloring component has been poor.

  Therefore, in the treatment of water containing coloring components and surfactants, particularly coloring components and anionic surfactants, which are generated during toner production, the addition and aggregation of the flocculant to the raw water is performed when the flocculant is mixed. It is preferable to divide the tank into a reaction step for performing the reaction and a subsequent reaction step, and to install pH detection means for detecting the pH in each of the reaction step and the subsequent reaction step. Further, the pH at the time of addition of the flocculant in the reaction step is adjusted to a strong acidity of pH 2 to 3 (first pH adjustment step), and the pH in the reaction step is adjusted to pH 4 to 6 thereafter (second pH adjustment step). Is preferred.

  As a result, it is possible to improve the color removal treatment property of water containing a surfactant or the like generated from the toner manufacturing process or the like. In addition, the amount of the flocculant used for the treatment of water containing a surfactant or the like can be reduced. Furthermore, it is possible to carry out water treatment in consideration of the environment with almost no coloration of the treated water.

  The operation of the water treatment apparatus and the water treatment method according to this embodiment will be described with reference to FIG. In FIG. 3, the raw water containing the coloring component and the surfactant is temporarily stored in the raw water tank 10, and then the flocculant is added by a pump or the like while being rapidly stirred in the reaction tank 12 by stirring means such as a stirring blade. Then, the aggregation reaction is performed (reaction process). At this time, the pH at the time of addition of the flocculant is adjusted to, for example, a strong acidity of pH 2 to 3 inclusive. The reaction solution that has undergone the agglutination reaction is sent to the post-reaction tank 42. In the post-reaction tank 42, the post-reaction is performed while being rapidly stirred by stirring means such as a stirring blade (post-reaction step). At this time, the pH in the subsequent reaction step is adjusted to, for example, pH 4 or more and 6 or less. Thereafter, after the post-reaction is performed, the post-reaction liquid is sent to the aggregation tank 14. Thereafter, the treatment is performed in the same manner as the water treatment method of FIG.

  As shown in FIG. 4, the water treatment device 4 includes a surface tension measuring device 40 that is a surface tension measuring device, a post-reaction tank 42, a first pH detecting device 44, and a second pH detecting device 46 in addition to the configuration of FIG. 1. May be provided.

  The water treatment apparatus and the water treatment method according to the embodiment of the present invention have been described above using water discharged from the electrophotographic toner manufacturing process as an example of water to be treated. However, the present invention is not limited to this. is not. The water treatment apparatus and the water treatment method according to the present embodiment include water to be treated containing a surfactant and a colorant discharged in a production process of a water-based dispersion production plant such as a water-based paint, a production process of a water-based ink, and the like. Can also be applied. Moreover, depending on the property of to-be-processed water, a biological treatment process, post-filtration processes, such as sand filtration and activated carbon filtration, may be omitted. That is, the configuration of the water treatment apparatus may be determined as appropriate depending on the properties of the treated water.

  In the water treatment apparatus and the water treatment method according to the embodiment of the present invention, it is preferable to treat water discharged from the manufacturing process of the electrophotographic toner using the surfactant and the colorant. In addition, the water treatment apparatus and the water treatment method according to the present embodiment are manufactured by various chemical toner production methods such as an emulsion polymerization method, a suspension polymerization method, and a dissolution suspension method, in particular, a large amount of silica and a surfactant. It is preferably applicable to the treatment of water discharged from the toner production process by the emulsion polymerization method used in the above. In the emulsion polymerization method, a resin dispersion formed by emulsion polymerization of a binder resin polymerizable monomer, a colorant, a release agent, and, if necessary, a charge control agent are stirred and mixed in an aqueous solvent. Then, toner particles that are colored resin particles having a predetermined particle size, particle size distribution, shape, and structure are produced by aggregation and heat fusion. The emulsion polymerization method is roughly divided into a production process of resin particles as a raw material of toner, a production process of a dispersion such as a colorant dispersion and a release agent dispersion, and a production process of a developing toner. Below, an example is given and demonstrated about each.

<Production process of resin particles>
In order to produce resin particles, a polymerizable monomer and a surfactant are usually added to water and stirred to form an emulsion. Once a polymerizable monomer emulsion is formed, preferably 25 wt% or less of the emulsion (ie, a small amount of emulsion) and a free radical initiator are added to the aqueous phase and mixed and seeded at the desired reaction temperature. To start. After the seed particles are generated, the remaining emulsion is further added to the seed particle-containing composition, and polymerization is continued at a predetermined temperature for a predetermined time to complete the polymerization, thereby generating resin particles (emulsion dispersion). From the resin particle production process, an emulsion dispersion containing a solid content such as a surfactant, which is not necessary in the production process or generated during equipment maintenance in the production process, is discharged. When the resin particles are produced, they are aggregated together with a colorant dispersion, a release agent dispersion and the like to form aggregate particles, which are then fused to form toner particles.

  The type of the polymerizable monomer is not particularly limited as long as it can react with a free radical initiator. Specific examples of the polymerizable monomer include styrenes such as styrene, parachlorostyrene, and α-methylstyrene; methyl acrylate, ethyl acrylate, n-propyl acrylate, n-butyl acrylate, lauryl acrylate, Esters having vinyl groups such as 2-ethylhexyl acrylate, methyl methacrylate, ethyl methacrylate, n-propyl methacrylate, lauryl methacrylate, 2-ethylhexyl methacrylate; vinyl nitriles such as acrylonitrile and methacrylonitrile These polymerizable monomers are polymerized into a homopolymer or a copolymer.

  Further, resins such as polyesters and polyurethanes 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 resin particle is also used.

  An anionic surfactant, a cationic surfactant, or a nonionic surfactant can be used as the surfactant used in the production of the resin particles. In general, an anionic surfactant has a dispersion force. Is preferable because it is strong and excellent in dispersion of resin particles. The nonionic surfactant is preferably used in combination with the anionic surfactant or the cationic surfactant. The said surfactant may be used individually by 1 type, and may be used in combination of 2 or more type.

  Specific examples of anionic surfactants include fatty acid soaps such as potassium laurate, sodium oleate, and castor oil sodium; sulfates such as octyl sulfate, lauryl sulfate, lauryl ether sulfate, and nonyl phenyl ether sulfate; lauryl sulfonate , Sodium alkylarylsulfonates such as dodecylbenzenesulfonate, triisopropylnaphthalenesulfonate, dibutylnaphthalenesulfonate; sulfones such as naphthalenesulfonate formalin condensate, monooctylsulfosuccinate, dioctylsulfosuccinate, lauric acid amide sulfonate, oleic acid amide sulfonate Acid salts; lauryl phosphate, isopropyl phosphate, nonylphenyl ether phosphate Phosphoric acid esters such as Feto; dialkyl sulfosuccinate salts such as sodium dioctyl sulfosuccinate; sulfosuccinate salts such as sulfosuccinate lauryl disodium; and the like.

  Specific examples of the cationic surfactant include laurylamine hydrochloride, stearylamine hydrochloride, oleylamine acetate, stearylamine acetate, stearylaminopropylamine acetate, and other amine salts; lauryltrimethylammonium chloride, dilauryldimethylammonium Chloride, distearyldimethylammonium chloride, distearyldimethylammonium chloride, lauryldihydroxyethylmethylammonium chloride, oleylbispolyoxyethylenemethylammonium chloride, lauroylaminopropyldimethylethylammonium ethosulphate, lauroylaminopropyldimethylhydroxyethylammonium perchlorate, alkylbenzene Trimethylammonium chloride, Quaternary ammonium salts such as quilts trimethyl ammonium chloride; and the like.

  Specific examples of the nonionic surfactant include alkyl ethers such as polyoxyethylene octyl ether, polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether; polyoxyethylene octyl phenyl ether, polyoxy Alkyl phenyl ethers such as ethylene nonyl phenyl ether; alkyl esters such as polyoxyethylene laurate, polyoxyethylene stearate, polyoxyethylene oleate; polyoxyethylene lauryl amino ether, polyoxyethylene stearyl amino ether, polyoxyethylene Alkylamines such as oleyl amino ether, polyoxyethylene soybean amino ether, polyoxyethylene beef tallow amino ether; Alkyl amides such as ethylene lauric acid amide, polyoxyethylene stearic acid amide, polyoxyethylene oleic acid amide; vegetable oil ethers such as polyoxyethylene castor oil ether and polyoxyethylene rapeseed oil ether; lauric acid diethanolamide, stearic acid Alkanolamides such as diethanolamide and oleic acid diethanolamide; sorbitan ester ethers such as polyoxyethylene sorbitan monolaurate, polyoxyethylene sorbitan monopalmitate, polyoxyethylene sorbitan monostearate, polyoxyethylene sorbitan monooleate And so on.

  There is no restriction | limiting in particular as a free radical initiator. Specifically, hydrogen peroxide, acetyl peroxide, cumyl peroxide, tert-butyl peroxide, propionyl peroxide, benzoyl peroxide, chlorobenzoyl peroxide, dichlorobenzoyl peroxide, bromomethylbenzoyl peroxide, lauroyl peroxide Ammonium persulfate, sodium persulfate, potassium persulfate, diisopropyl peroxycarbonate, tetralin hydroperoxide, 1-phenyl-2-methylpropyl-1-hydroperoxide, tert-butyl hydroperoxide pertriphenyl acetate, tert-butyl formate, Peroxides such as tert-butyl peracetate, tert-butyl perbenzoate, tert-butyl perphenylacetate, tert-butyl permethoxyacetate, tert-butyl perN- (3-toluyl) carbamate; 2,2 '-Azobispro 2,2'-dichloro-2,2'-azobispropane, 1,1'-azo (methylethyl) diacetate, 2,2'-azobis (2-diaminopropane) hydrochloride, 2,2 ' -Azobis (2-diaminopropane) nitrate, 2,2'-azobisisobutane, 2,2'-azobisisobutyramide, 2,2'-azobisisobutyronitrile, 2,2'-azobis-2- Methyl methylpropionate, 2,2′-dichloro-2,2′-azobisbutane, 2,2′-azobis-2-methylbutyronitrile, dimethyl 2,2′-azobisisobutyrate, 1,1′-azobis (1 -Methylbutyronitrile-3-sodium sulfonate), 2- (4-methylphenylazo) -2-methylmalonodinitrile, 4,4'-azobis-4-cyanovaleric acid, 3,5-dihydroxymethylphenyl A Zo-2-methylmalonodinitrile, 2- (4-bromophenylazo) -2-allylmalonodinitrile, 2,2'-azobis-2-methylvaleronitrile, 4,4'-azobis-4-cyanoyoshi Dimethyl herbate, 2,2′-azobis-2,4-dimethylvaleronitrile, 1,1′-azobiscyclohexanenitrile, 2,2′-azobis-2-propylbutyronitrile, 1,1′-azobis-1 -Chlorophenylethane, 1,1'-azobis-1-cyclohexanecarbonitrile, 1,1'-azobis-1-cycloheptanenitrile, 1,1'-azobis-1-phenylethane, 1,1'-azobiscumene, 4-Nitrophenylazobenzylcyanoacetate, phenylazodiphenylmethane, phenylazotriphenylmethane, 4-nitrophenylazotriphe Nylmethane, 1,1′-azobis-1,2-diphenylethane, poly (bisphenol A-4,4′-azobis-4-cyanopentanoate), poly (tetraethylene glycol-2,2′-azobisiso) Azo compounds such as butyrate); 1,4-bis (pentaethylene) -2-tetrazene, 1,4-dimethoxycarbonyl-1,4-diphenyl-2-tetrazene and the like.

  In the present embodiment, the size of the resin particles is about 0.05 μm to 1 μm in terms of volume average particle size measured with a laser diffraction particle size distribution measuring device (Microtrack manufactured by Nikkiso Co., Ltd.).

<Production process of colorant dispersion and release agent dispersion>
The colorant dispersion is obtained by mixing a colorant, a surfactant and the like in an aqueous phase and performing a dispersion treatment. Similarly, the release agent dispersion is obtained by mixing a release agent, a surfactant and the like in an aqueous phase and performing a dispersion treatment. Coloring that contains solids such as surfactants and colorants, which are no longer necessary in the manufacturing process from the manufacturing process of the colorant dispersion and the release agent dispersion, or are generated by equipment maintenance in the manufacturing process. An agent dispersion, a release agent dispersion containing a solid content such as a surfactant and a release agent, and the like are discharged.

  Examples of the colorant 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, brilliant carmine 3B, brilliant carmine 6B, and Dupont. Oil red, pyrazolone red, resol red, rhodamine B lake, lake red C, rose bengal, aniline blue, ultramarine blue, calco oil blue, methylene blue chloride, phthalocyanine blue, phthalocyanine green, malachite green oxalate, etc. Pigment: Acridine, xanthene, azo, benzoquinone, azine, anthraquinone, dioxadi System, thiazine, azomethine, indigo, thioindigo, phthalocyanine, aniline black, polymethine, triphenylmethane dyes, diphenylmethane dyes, and the like various dyes, such as thiazole. These colorants may be used alone or in combination of two or more.

  The size of the colorant in the colorant dispersion is, for example, about 0.05 μm to 0.5 μm, which is a volume average particle size measured with the laser diffraction particle size distribution measuring apparatus (Microtrack manufactured by Nikkiso Co., Ltd.). is there.

  The type of wax that acts as a mold release agent is not particularly limited. For example, low molecular weight polyolefins such as polyethylene, polypropylene, and polybutene; silicones having a softening point; oleic acid amide, erucic acid amide, ricinoleic acid amide, Fatty acid amides such as stearamide; 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, micro And mineral waxes such as crystallin wax and Fischer-Tropsch wax; and ester waxes of higher fatty acids such as stearyl stearate and behenyl behenate and higher alcohols.

  The size of the release agent in the release agent dispersion is, for example, 0.05 μm to 0.5 μm in volume average particle size measured with the laser diffraction particle size distribution measuring apparatus (Microtrack manufactured by Nikkiso Co., Ltd.). Degree.

  Examples of the surfactant include the same surfactants used for the production of the resin particles.

<Manufacturing process of developing toner>
The resin particles obtained by the above preparation method are used for toner preparation by the following method. Resin particles obtained by the above preparation method, a colorant dispersion, a release agent dispersion, a flocculant as necessary, a charge control agent as necessary, and other additives as necessary And the resulting mixture at a temperature in the vicinity of the glass transition temperature (Tg) of the resin particles, preferably Tg ± 10 ° C. of the resin particles, for a time effective to form an aggregate, for example 1 to Heat for 8 hours to produce toner-sized aggregates. The aggregate suspension is then heated to a resin particle Tg or higher temperature, preferably Tg + 40 ° C. of the resin particles, for example, about 60 to about 120 ° C. to coalesce or fuse to form toner particles. Then, the toner particles are separated from the mother liquor by means such as filtration, washed with ion-exchanged water or the like (washing process), and then dried.

  The resin particles are usually used as a binder resin for toner, and are present in the toner at about 75 to 98% by weight with respect to the solid content of the toner.

  The colorant is usually present in the toner in an amount effective for coloring, for example, about 1 to 15% by weight, preferably about 3 to 10% by weight, based on the solid content of the toner.

  A preferable amount of the wax acting as a release agent is about 5 to 20% by weight based on the solid content of the toner.

  The coagulant used as necessary can be used in an amount effective for fusion, 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 aforementioned anionic surfactants; acids such as hydrochloric acid, sulfuric acid, nitric acid, acetic acid and oxalic acid; Examples include, but are not limited to, salts such as magnesium, sodium chloride, aluminum sulfate, calcium sulfate, ammonium sulfate, aluminum nitrate, silver nitrate, copper sulfate, sodium carbonate, and polyaluminum chloride. Preferred flocculants include those having a nitrogen component such as nitric acid.

  The charge control agent may be used in an amount effective for charging, for example, 0.1 to 5% by weight based on the solid content 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.

  In addition, inorganic particles or the like may be wet-added as an additive as necessary. Examples of inorganic 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, a polymer base or the like, and wet-added as an inorganic particle dispersion such as silica.

  The size of the inorganic particles used in the present embodiment in the dispersion is a volume average particle size measured by the laser diffraction particle size distribution measuring apparatus (Microtrack manufactured by Nikkiso Co., Ltd.) and is about 4 nm to 150 nm.

  The manufacturing process (including the toner cleaning process) such as the resin particle manufacturing process, the colorant dispersion manufacturing process, the release agent dispersion manufacturing process, and the toner manufacturing process is not necessary in the manufacturing process. Or a surfactant aqueous solution containing a solid content such as a surfactant, a colorant, a release agent, inorganic particles, and a toner generated by equipment maintenance in the manufacturing process, an emulsion dispersion, a colorant dispersion, Release agent dispersion liquid, inorganic particle dispersion liquid, toner dispersion liquid, apparatus cleaning water and the like are discharged. These raw waters are collected in a raw water tank and treated by the above water treatment method.

  Hereinafter, although an example and a comparative example are given and the present invention is explained more concretely in detail, the present invention is not limited to the following examples.

<Example of production of toner for electrophotography>
In the following, an example of producing an electrophotographic toner in which water subjected to water treatment in this example and a comparative example is discharged will be shown.
[Preparation of emulsion dispersion]
Styrene 320 parts by weight n-butyl acrylate 80 parts by weight Acrylic acid 10 parts by weight Dodecanethiol 10 parts by weight This solution 420 parts by weight, a nonionic surfactant (Sanyo Kasei Co., Ltd., Nonipol 400) 6 parts by weight, and anionic A solution obtained by dissolving 10 parts by weight of a surfactant (Daiichi Kogyo Seiyaku Co., Ltd., Neogen R) in 550 parts by weight of ion-exchanged water is placed in a flask to disperse and emulsify, and while stirring and mixing slowly for 10 minutes, 50 parts by weight of ion-exchanged water in which 4 parts by weight of ammonium persulfate was dissolved was added. Thereafter, the inside of the flask was sufficiently replaced with nitrogen and then heated with stirring in an oil bath until the temperature in the system reached 70 ° C., and emulsion polymerization was continued for 5 hours to obtain an emulsion dispersion.

The resin particles obtained from the emulsion dispersion were 155 nm when the volume average particle diameter (D ₅₀ ) of the resin particles was measured with a laser diffraction particle size distribution analyzer (Microtrack manufactured by Nikkiso Co., Ltd.), and a differential scanning calorimeter ( When the glass transition point of the resin was measured at a heating rate of 10 ° C / min using Shimadzu Corporation, DSC-50), it was 54 ° C, and a molecular weight measuring instrument (HLC-8020, manufactured by Tosoh Corporation) was used. It was 33,000 when the weight average molecular weight (polystyrene conversion) was measured using THF as a solvent.

[Preparation of colorant dispersion]
Pigment 150 parts by weight Anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) 20 parts by weight Ion-exchanged water 400 parts by weight The above is mixed and dispersed with an optimizer to obtain a colorant dispersion. It was adjusted. The pigment is C.I. for yellow. I. Pigment Yellow 74 (manufactured by Dainichi Seika), C.I. I. Pigment Blue 15: 3 (manufactured by BASF), C.I. I. Pigment Red 122 (manufactured by Dainichi Seika Co., Ltd.) and carbon black (manufactured by Cabot Corp.) were used.

[Preparation of release agent dispersion]
Paraffin wax (Nippon Seiwa Co., Ltd .: HNP0190, melting point 85 ° C.) 50 parts by weight Cationic surfactant (Kao Co., Ltd .: Sanizol B50) 5 parts by weight Ion-exchanged water 200 parts by weight Heating at 95 ° C. Then, after dispersing using a homogenizer (manufactured by IKA: Ultra Tarrax T50), the dispersion is performed by a pressure discharge type homogenizer, and a release agent having a volume average particle size of 550 nm is dispersed. A liquid was prepared.

[Preparation of agglomerated particles]
Emulsion dispersion 200 parts by weight Colorant dispersion 30 parts by weight Release agent dispersion 70 parts by weight Cationic surfactant (manufactured by Kao Corporation: SANISOL B50) 1.5 parts by weight In a round stainless steel flask After mixing and dispersing using a homogenizer (manufactured by IKA: Ultra Tarrax T50), the mixture was 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]
60 parts by weight of the resin particle dispersion was gradually added to the prepared dispersion of aggregated particles. The volume of the resin particles contained in the resin particle dispersion was 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.

  Then, after adding 3 parts by weight of an anionic surfactant (Neogen SC: manufactured by Daiichi Kogyo Seiyaku Co., Ltd.) to the prepared dispersion of adhered particles, the stainless steel flask was sealed and a magnetic seal was used. The mixture was heated to 105 ° C. and kept for 3 hours while stirring was continued. Then, after cooling, the reaction product was filtered, thoroughly washed with ion exchange water, and then dried to obtain an electrophotographic toner.

[Composition of water A]
Water A is water discharged from the washing process of the manufacturing plant where the electrophotographic toner is manufactured, and includes a pigment dispersion, a release agent (wax) dispersion, an emulsion dispersion, an interface Water containing an aqueous activator solution, silica and the like. The main composition of water A is shown below. Water A contained a surfactant, latex polymer, colorant, wax, silica and the like. The solid content concentration of water A was 0.01% by weight, and the chemical oxygen demand was 20 mg / L.
Surfactant 0.008 part by weight Latex polymer 0.004 part by weight Colorant 0.016 part by weight Wax 0.012 part by weight Silica 0.06 part by weight Water 999.9 part by weight

  The solid content concentration was measured by a method in which a water sample was placed in an aluminum container and the water was evaporated in an oven. The chemical oxygen demand was measured by a method defined in JIS K 0102 17. Specifically, this is a test method in which an oxidant is added to a sample and allowed to react under a certain condition, and the amount of oxidant consumed at that time is expressed in terms of oxygen.

[Composition of water B]
The water B is water discharged from the washing process of the manufacturing factory that manufactures the electrophotographic toner, and the composition of the water A is almost the same but the concentration is different. The main composition of water B is shown below. Water B contains a surfactant, latex polymer, colorant, release agent (wax), silica, and the like. The solid content concentration of water B is 5% by weight, and the chemical oxygen demand is 1000 mg / L. It was.
Surfactant 4 parts by weight Latex polymer 2 parts by weight Colorant 8 parts by weight Wax 6 parts by weight Silica 30 parts by weight Water 950 parts by weight

Example 1
[Treatment of water A]
Water A having a solid concentration of 0.01% by weight discharged from the toner production process was treated using the water treatment apparatus shown in FIG. First, water A is stored in the raw water tank 10 and then pumped to the reaction tank 12, and 1000 mg / L of an inorganic flocculant (ferric chloride, 38 wt% aqueous solution) and a polymer flocculant ( 1 mg / L of acrylamide polymer flocculant, Hymo Lock SS-100, manufactured by Hymo Co., Ltd., 0.1 wt% aqueous solution) was added, and the agglutination reaction was carried out at a stirring speed of 500 rpm and a residence time of 10 minutes. The pH in the reaction vessel 12 was adjusted to 7.0 ± 0.5. Next, the obtained reaction liquid was pumped to the coagulation tank 14 (18 m ³ ), and floc formation was performed at a stirring speed of 300 rpm and a residence time of 10 minutes. The floc formation was good. Next, the processing liquid floc-formed in the coagulation tank 14 was sent to the coagulation sedimentation tank 16 by a pump. The fed processing liquid was separated into sludge slurry and flocs in which flocs were concentrated by natural sedimentation separation in the coagulation sedimentation tank 16. The time required for the separation was 1 hour. The separated liquid was pumped to the biological treatment tank 18. The separated liquid is subjected to biological treatment (activated sludge treatment) in the biological treatment tank 18, and then separated into activated sludge and supernatant water by natural sedimentation in the post-precipitation tank 20, and the supernatant water is further separated into a sand filtration device 22 and an activated carbon filtration adsorption device. The solution was sent to 24 and filtered. The chemical oxygen demand of this water was <5 mg / L. The sludge slurry separated from the separated liquid in the coagulation sedimentation tank 16 and the sludge slurry obtained in the post-precipitation tank 20 are first stored in the sludge slurry storage tank 26, and then sent to the mixing tank 28 by a pump. Calcium carbonate was added at 500 mg / L, and mixing was performed at a stirring speed of 500 rpm and a residence time of 10 minutes. Next, the obtained liquid mixture was pumped to the sludge reaction tank 30 (18 m ³ ) and reacted at a stirring speed of 200 rpm and a residence time of 10 minutes. Then, the liquid mixture was sent to the sludge concentration apparatus 32 with the pump. The liquid mixture sent was separated into sludge and sludge separation liquid by natural sedimentation. The sludge was recovered as sludge through a dehydration process by the dehydrator 34. Water A was treated with 18 m ³ , but the treated water (sludge separation liquid) was clear and transparent, and the chemical oxygen demand of this sludge separation liquid was <5 mg / L. The final sludge generation amount was 1.1 g / L. The results are shown in Table 1.

(Example 2)
[Treatment of water B]
Water B having a solid content concentration of 5% by weight discharged from the toner production process was treated using the water treatment apparatus shown in FIG. For water B, inorganic flocculant (ferric chloride, 38 wt% aqueous solution) is 2000 mg / L and polymer flocculant (acrylamide polymer flocculant, Hymo Lock SS-100, manufactured by Hymo Co., Ltd., 0.1 wt%) Aqueous solution) 2 mg / L was added, and the rest was obtained in the sludge slurry separated from the separated liquid in the coagulation sedimentation tank 16 and the post-precipitation tank 20 after performing the coagulation sedimentation treatment in the same manner as in Example 1. The sludge slurry was first stored in the sludge slurry storage tank 26, then sent to the mixing tank 28 by a pump, added with 1000 mg / L of calcium carbonate, and mixed at a stirring speed of 500 rpm and a residence time of 10 minutes. . Next, the obtained liquid mixture was pumped to the sludge reaction tank 30 (18 m ³ ) and reacted at a stirring speed of 200 rpm and a residence time of 10 minutes. Then, the liquid mixture was sent to the sludge concentration apparatus 32 with the pump. The liquid mixture sent was separated into sludge and sludge separation liquid by natural sedimentation. The sludge was recovered as sludge through a dehydration process by the dehydrator 34. Water B was treated with 18 m ³ , but the treated water (sludge separation liquid) was clear and transparent, and the chemical oxygen demand of this sludge separation liquid was <5 mg / L. The final sludge generation amount was 550 g / L. The results are shown in Table 1.

(Comparative Example 1)
[Treatment of water A]
Using a water treatment apparatus as shown in FIG. 5, the inorganic flocculant (ferric chloride, 38% by weight aqueous solution) is 2000 mg / L and the polymer flocculant (acrylamide polymer flocculant, Hymolock SS-100). , Manufactured by Hymo Co., Ltd., 0.1 wt% aqueous solution), 2 mg / L was added, and calcium carbonate was not added to the sludge slurry. Otherwise, the solid content discharged from the toner manufacturing process was the same as in Example 1. Water A having a concentration of 0.01% by weight was treated. The chemical oxygen demand of the sludge separation liquid separated by the sludge concentrator 32 was <5 mg / L. When the water A was treated at 18 m ^{3, the} treated water (sludge separation liquid) was not colored, and the final sludge generation amount was 1.2 g / L. The results are shown in Table 1.

(Comparative Example 2)
[Treatment of water B]
Using a water treatment apparatus as shown in FIG. 5, the inorganic flocculant (ferric chloride, 38% by weight aqueous solution) is 4000 mg / L and the polymer flocculant (acrylamide polymer flocculant, Hymolock SS-100). In addition to the above, a solid content discharged from the toner production process is the same as in Example 2 except that calcium carbonate is not added to the sludge slurry. Water B having a concentration of 5% by weight was treated. The chemical oxygen demand of the sludge separation liquid separated by the sludge concentrator 32 was <5 mg / L. When the water B was treated at 18 m ^{3, the} treated water (sludge separation liquid) was not colored, and the final sludge generation amount was 700 g / L. The results are shown in Table 1.

(Example 3)
[Treatment of water B]
Using a water treatment apparatus as shown in FIG. 2, water B having a solid content concentration of 5% by weight discharged from the toner production process was treated in the same manner as in Example 2. The supply amount of the flocculant supply device was set to 2000 mg / L for the inorganic flocculant (ferric chloride) when the surface tension was less than 50 mN / m, and to 1500 mg / L when the surface tension was 50 mN / m or more. As a result of measuring water B with a surface tension measuring device (for example, a fully automatic surface tension meter manufactured by Kyowa Interface Science), the surface tension was 52 mN / m. At this time, 1500 mg / L of the inorganic flocculant (ferric chloride) and 2 mg / L of the polymer flocculant (acrylamide polymer flocculant, Hymolock SS-100) were added in a total amount, and normal operation (18 m ³ / h ). The chemical oxygen demand of the sludge separation liquid separated by the sludge concentrator 32 was <5 mg / L. When the water B was treated at 18 m ^{3, the} treated water (sludge separation liquid) was not colored, and the final sludge generation amount was 540 g / L. The results are shown in Table 1.

Example 4
[Treatment of water B]
Water B having a solid content concentration of 5% by weight discharged from the toner manufacturing process was treated using a water treatment apparatus as shown in FIG. While rapidly stirring at 300 rpm in the reaction vessel 12, 1500 mg / L was added using ferric chloride as an inorganic flocculant, and an anionic polymer flocculant (acrylamide polymer flocculant, Hymorlock SS was used as an organic flocculant. −100) 2 mg / L was added to conduct an agglutination reaction. At this time, the pH when the flocculant was added was adjusted to 2 ± 0.2. The reaction solution was sent to the post-reaction vessel 42, and the post-reaction was performed in the post-reaction vessel 42 while rapidly stirring at 300 rpm. At this time, the pH in the subsequent reaction step was adjusted to 4 ± 0.2. Otherwise, the same process as in Example 2 was performed. The chemical oxygen demand of the sludge separation liquid separated by the sludge concentrator 32 was <5 mg / L. When the water B was treated at 18 m ^{3, the} treated water (sludge separation liquid) was not colored, and the final sludge generation amount was 540 g / L. The results are shown in Table 1.

(Example 5)
[Treatment of water B]
The same treatment as in Example 4 was conducted except that the pH in the post reaction step was adjusted to 6 ± 0.2. The chemical oxygen demand of the sludge separation liquid separated by the sludge concentrator 32 was <5 mg / L. When the water B was treated at 18 m ^{3, the} treated water (sludge separation liquid) was not colored, and the final sludge generation amount was 540 g / L. The results are shown in Table 1.

  As can be seen from Table 1, in Examples 1 to 5, compared to Comparative Examples 1 and 2, the amount of flocculant used and the amount of sludge generated could be reduced. Moreover, in Examples 3, 4 and 5, the sludge generation amount was 540 g / L, and all of the sludge generation amount could be reduced as compared with Comparative Example 2 in which the water B having a solid content concentration of 5% by weight was treated. .

It is a schematic structure figure showing an example of the water treatment equipment concerning the embodiment of the present invention. It is a schematic block diagram which shows the other example of the water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the other example of the water treatment apparatus which concerns on embodiment of this invention. It is a schematic block diagram which shows the conventional water treatment apparatus.

Explanation of symbols

  1, 2, 3, 4, 5 Water treatment apparatus, 10 Raw water tank, 12 Reaction tank, 14 Coagulation tank, 16 Coagulation sedimentation tank, 18 Biological treatment tank, 20 Post-precipitation tank, 22 Sand filtration apparatus, 24 Activated carbon filtration adsorption apparatus , 26 Sludge slurry storage tank, 28 Mixing tank, 30 Sludge reaction tank, 32 Sludge concentration apparatus, 34 Dehydration apparatus, 36 Calcium salt tank, 38 Valve, 40 Surface tension measurement apparatus, 42 Post reaction tank, 44 First pH detection means, 46 Second pH detection means.

Claims (4)

Treated with water to be treated containing at least coloring components,
Calcium salt addition means for adding calcium salt to the treated water;
A mixing tank for mixing the water to be treated and the calcium salt;
Separation means for separating the solid content and moisture in the mixed liquid mixture;
A water treatment apparatus comprising: Treated with water to be treated containing at least coloring components,
A reaction tank for carrying out the aggregation reaction of the water to be treated;
A floc separating means for separating the floc formed from the agglomerated aggregate and the separation liquid;
Calcium salt addition means for adding calcium salt to the flock;
A mixing tank for mixing the floc and the calcium salt;
Separation means for separating the solid content and moisture in the mixed liquid mixture;
A water treatment apparatus comprising: Treated with water to be treated containing at least coloring components,
A mixing step of adding and mixing a calcium salt to the treated water;
A separation step of separating solids and moisture in the mixed liquid mixture;
A water treatment method comprising: Treated with water to be treated containing at least coloring components,
A reaction step of adding a flocculant to the water to be treated and performing a flocculence reaction;
A floc forming step of forming a floc from the aggregate that has undergone agglomeration reaction in the reaction step;
A floc separation step for separating the floc and the separation liquid;
A mixing step of adding calcium salt to the floc and mixing,
A separation step of separating solids and moisture in the mixed liquid mixture;
A water treatment method comprising:

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