JPWO2006090859A1 - Water-soluble processing fluid recycling method, water-soluble processing fluid recycling device, oil-containing wastewater treatment method, and oil-containing wastewater treatment device - Google Patents

Abstract

Provided is a method for efficiently separating oil to a level capable of draining without adjusting pH of oil-containing wastewater or complicated temperature control, and a method for obtaining microorganisms having oil decomposability used in the method. Oil-containing wastewater is treated by combining oil-degradable microorganisms, mineral oil gelling coagulant and activated carbon. Microorganisms are obtained by keeping a used water-soluble mold release agent for hot forging in a container at an elevated temperature for several days.

Description

  The present invention relates to a method for recycling a water-soluble processing liquid using oil-degradable microorganisms.

  Interest in environmental issues has been increasing rapidly in recent years, and consideration is given to environmental load in production activities of companies. Particularly in the field of machining, there are problems of deterioration of the working environment due to the use of machining fluids such as cutting fluids and grinding fluids, and environmental burden due to disposal of the machining fluid. For this reason, it is said that the machining fluid used in machining tends to shift from water-insoluble to water-soluble, and even water-soluble machining fluid tends to shift from emulsion type to soluble and solution type (Susumu Sugata, JIS revision) Current status and problems of later cutting fluids, mechanical technology, 50-12 (2002), p.17-20).

  One of the problems with water-soluble processing liquids is waste liquid treatment. BACKGROUND ART Oil-in-water emulsified oil or solubilized oil in which oil is finely dispersed in water is widely used in various industries such as machining. If water is discharged without appropriate treatment after using these oil-containing solutions, the water quality of the ocean and rivers can have a fatal effect on people's health, birds and seafood. Since the oil-containing wastewater contains a surfactant in addition to the oil, the oil often does not separate and forms a stable emulsion.

  Conventional techniques for separating oil in emulsion wastewater include mechanical separation methods such as filtration and centrifugation, physical or chemical methods using membrane separation, ultrasonic waves, heating, cooling, aggregation, photocatalyst, and microorganisms. There is a method using. Examples of waste liquid treatment methods for water-soluble processing fluids that are often used include incineration and coagulation precipitation (Hideki Yasui, basic knowledge and practical selection / management technology for cutting fluids, mechanical technology, 50-12 (2002)). , P.21-28).

However, the prior art described in the above literature has room for improvement in the following points.
The coagulation sedimentation method, which is the most widely used oil-containing wastewater treatment method, has many problems such as complicated management and large equipment because pH adjustment is complicatedly incorporated in the treatment process. In addition, membrane separation methods are subject to problems such as the separation efficiency tends to decrease due to clogging of the membrane, the maintenance of the equipment to prevent it is very complicated, and some oil droplets pass through the membrane. is there. In the mechanical separation method such as filtration and centrifugal separation and the physical separation method such as ultrasonic waves, it becomes difficult to separate the oil when the dispersed particle size of the oil is small. Furthermore, the photocatalytic method and the method using microorganisms have a problem that it takes a very long time to decompose the oil. In addition, oil-containing wastewater discharged from machine tools or the like has a complicated composition in which organic substances, inorganic substances, and oils are mixed, and it is difficult to reduce COD and n-hexane values to a reference value that allows drainage by the conventional process.

  Therefore, a lot of labor and time are required to process the used processing liquid to a level at which it can be drained by the coagulation sedimentation method. In addition, in the incineration method, environmental pollution due to nitrogen oxides, sulfur oxides, carbon dioxide gas, etc. generated during incineration has been pointed out. For this reason, the processing of the water-soluble processing liquid generated at business establishments costs about several tens of yen per liter, which increases the processing cost.

  This invention is made | formed in view of the said situation, and it aims at providing the technique which processes oil-containing wastewater and isolate | separates an oil component efficiently. Another object of the present invention is to provide a microorganism having oil decomposability used in the technique.

  According to the present invention, a step of treating a used water-soluble processing liquid containing mineral oil under anaerobic conditions at 37 ° C. or more and 60 ° C. or less with an oil-degradable microorganism, and a used water-soluble processing after treatment with a microorganism. Treating the liquid with an oil coagulant that coagulates the mineral oil into a gel to at least partially coagulate and remove the oil in the used water-soluble processing liquid; A method for recycling a used water-soluble processing liquid, comprising the step of treating an oil-soluble processing liquid with a biological activated carbon comprising an oil-degrading microorganism and an activated carbon carrying the oil-degrading microorganism.

  According to this method, it is possible to destabilize the emulsion in the used water-soluble processing liquid by treating the used water-soluble processing liquid with oil-degradable microorganisms under anaerobic conditions of 37 ° C. or more and 60 ° C. or less. . As a result, by treating the mineral oil with an oil coagulant that coagulates in a gel state, a part of the emulsion destabilized by the oil-degradable microorganisms can be coagulated and removed. Then, by removing the remaining emulsion by adsorption using biological activated carbon containing oil-degrading microorganisms, it is possible to efficiently separate the oil and recycle the used water-soluble processing liquid.

  According to the present invention, a used water-soluble processing liquid containing mineral oil is treated with an oil-degradable microorganism under an anaerobic condition at 37 ° C. or more and 60 ° C. or less, and a used water solution that has been treated with a microorganism. An oil coagulation removal tank that removes at least a part of the oily processing liquid by treating it with an oil coagulant that coagulates mineral oil into a gel to coagulate and remove at least part of the oily agent in the used water-soluble processing liquid A biological activated carbon treatment tank for treating the used spent water-soluble processing liquid with a biological activated carbon comprising an oil-degrading microorganism and an activated carbon supporting the oil-degrading microorganism. Recycling equipment is provided.

  According to this configuration, it is possible to destabilize the emulsion in the used water-soluble processing liquid by treating the used water-soluble processing liquid with an oil-degradable microorganism under anaerobic conditions of 37 ° C. or more and 60 ° C. or less. . As a result, by treating the mineral oil with an oil coagulant that coagulates in a gel state, a part of the emulsion destabilized by the oil-degradable microorganisms can be coagulated and removed. Then, by removing the remaining emulsion by adsorption using biological activated carbon containing oil-degrading microorganisms, it is possible to efficiently separate the oil and recycle the used water-soluble processing liquid.

  According to the present invention, there is provided a method for treating oil-containing wastewater, comprising: treating oil-containing wastewater with oil-degradable microorganisms; and treating the oil-containing wastewater treated with the microorganisms with biological activated carbon. Provided.

  According to this method, since oil-degradable microorganisms and biological activated carbon are used in combination, oil-containing wastewater can be treated to efficiently separate oil.

  According to the present invention, a step of treating oil-containing wastewater with oil-degradable microorganisms, and treating the oil-containing wastewater that has been treated with the microorganisms with an oil coagulant to coagulate and remove the oil agent in the oil-containing wastewater. And a method for treating the oil-containing wastewater from which at least a part of the oil agent has been removed are treated with biological activated carbon.

  According to this method, since oil-decomposable microorganisms, oil coagulants and biological activated carbon are used in combination, oil-containing wastewater can be treated to efficiently separate the oil component.

  According to the present invention, there is provided a microbial treatment tank for treating oil-containing wastewater with oil-degradable microorganisms, and a biological activated carbon treatment tank for treating this oil-containing wastewater treated with the microorganisms with biological activated carbon. Waste water treatment equipment is provided.

  According to this configuration, since oil-degradable microorganisms and biological activated carbon are used in combination, the oil-containing wastewater can be treated to efficiently separate the oil.

  According to the present invention, a microbial treatment tank for treating oil-containing wastewater with oil-degradable microorganisms, and treating the oil-containing wastewater treated with the microorganism with an oil coagulant to at least partially solidify the oil agent in the oil-containing wastewater. There is provided an oil-containing wastewater treatment apparatus comprising: an oil coagulation removal tank that is removed in this manner; and a biological activated carbon treatment tank that treats this oil-containing wastewater from which at least a part of the oil agent has been removed with biological activated carbon.

  According to this structure, since oil-decomposable microorganisms, oil coagulants and biological activated carbon are used in combination, oil-containing wastewater can be treated to efficiently separate oil.

  Note that any combination of the above components, the expression of the present invention converted between a method for producing reclaimed water, a method for recycling water, a treatment system for oil-containing wastewater, microorganisms, additives, etc. are also aspects of the present invention. It is effective as

  According to the present invention, since oil-decomposable microorganisms and biological activated carbon are used in combination, oil-containing wastewater can be treated to efficiently separate oil.

It is a flowchart explaining the water resource collection | recovery method which concerns on embodiment. It is a microscope picture of the oil-degradable microorganisms used for the water resource collection | recovery method which concerns on embodiment. It is a conceptual diagram which illustrates typically the structure of the water resource collection | recovery system which concerns on embodiment. In the water resource recovery system which concerns on embodiment, it is the figure which showed a mode that the used water-soluble mold release agent for hot forging was maintained in the temperature rising state for several days within a container, and a microorganism was generated. In the water resource recovery system which concerns on embodiment, it is the figure which showed the mode of the change of the solution when the water-soluble processing liquid containing microorganisms was hold | maintained in the temperature rising state. In the water resource collection | recovery system which concerns on embodiment, it is a figure which shows the mode of the solution which can remove an oil phase from the water-soluble processing liquid which carried out the microorganism treatment, and the solution which processed this solution with the mineral oil gelatinization coagulant. In the water resource recovery system which concerns on embodiment, it is a figure which shows the mode of the water phase obtained by processing by the combination of the microorganisms which have oil decomposability, a mineral oil gelatinization coagulant, and activated carbon. It is a figure which shows the mode of the process (pre-processing) of the water-soluble cutting oil by the water resource collection | recovery system which concerns on embodiment. In the water resources recovery system concerning an embodiment, it is a graph which shows that oil decomposition is accelerated when microorganisms are added. It is a figure which shows the mode of the process (biological activated carbon process) of the water-soluble cutting oil by the water resource collection | recovery system which concerns on embodiment. It is a figure which shows the mode of the process (pretreatment) of the water-soluble graphite by the water resource collection | recovery system which concerns on embodiment. It is a figure which shows the mode of the process (biological activated carbon process) of the water-soluble graphite by the water resource collection | recovery system which concerns on embodiment. 1 is a conceptual diagram schematically showing the configuration of a water-soluble working fluid metabolism system according to Example 1. FIG. It is a graph which shows the comparison of the oil agent usage-amount of the water-soluble process fluid metabolism system which concerns on Example 1, and MQL process. 3 is a flowchart for explaining a water resource recovery flow of the water-soluble processing fluid metabolism system according to the first embodiment. It is a figure which shows the mode of the example of a process of the water-soluble graphite by the water-soluble process fluid metabolism system which concerns on Example 1. FIG. It is a figure which shows the mode of the example of a process of the water-soluble cutting oil by the water-soluble process fluid metabolism system which concerns on Example 1, and the evaluation of the availability of reclaimed water. It is a graph for demonstrating the addition effect of the microorganisms with respect to decomposition | disassembly of the oil component by the water-soluble process fluid metabolism system which concerns on Example 1. FIG. It is a figure which shows the mode of the example of a process of the emulsion type water-soluble cutting fluid by the water-soluble machining fluid metabolism system which concerns on Example 2. FIG. It is a figure which shows the adhesive test result of the water-soluble graphite for evaluating the performance of the reclaimed water regenerated with the water-soluble process fluid metabolism system which concerns on Example 2. FIG. It is a graph which shows the friction coefficient of the water-soluble graphite mold release agent obtained by the ring compression test for evaluating the performance of the reclaimed water regenerated with the water-soluble process fluid metabolism system which concerns on Example 2. FIG. It is the conceptual diagram which showed typically the mode of the manufacturing site where the used water-soluble processing liquid generate | occur | produces. It is a conceptual diagram for demonstrating that an environmental load is large when a used water-soluble processing fluid is processed by a combustion method. It is a figure for demonstrating that it is difficult to clear drainage regulation value when used water-soluble processing fluid is processed by the coagulation sedimentation method, Hideki Yasui, "Story of oil technology useful in the field", mechanical technology, 2003. Annual publication, p. 82-83. It is a figure explaining the method of isolating microorganisms from bacteria group TE-1. It is a figure for demonstrating the result investigated about the relationship between the oil-separation of the water-soluble processing liquid by microorganisms, and temperature.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same reference numerals are given to the same components, and the description will be omitted as appropriate.

<Embodiment 1>
The present embodiment relates to a treatment method useful for purification treatment of emulsion wastewater after using a water-soluble oil such as a water-soluble cutting fluid, and a microorganism used for the treatment.

  The water resource recovery method (oil-containing wastewater treatment method) according to the embodiment includes a step of treating a used water-soluble processing liquid (oil-containing wastewater) generated from the site with oil-degradable microorganisms, and a use after treatment with microorganisms. Treating the used water-soluble processing liquid with biological activated carbon.

  The water resource recovery method according to the embodiment may further include a step of treating the oil-containing wastewater that has been treated with microorganisms with an oil coagulant to coagulate and remove the oil agent in the oil-containing wastewater. At this time, the step of treating with biological activated carbon treats the oil-containing wastewater from which at least a part of the oil agent has been removed with biological activated carbon. The oil coagulant may have a property of coagulating mineral oil in a gel form. At this time, the water resource recovery method according to the embodiment may further include a step of removing a coagulum generated by the treatment with the oil coagulant.

  The oil-degrading microorganism may include a fungus group consisting of a fungus group name TE-1 (a fungus group deposited with a third party organization). This fungal group contains at least three types of microorganisms. One of the three strains is an oil-degrading strain of Pseudomonas aeruginosa, a Gram-negative bacilli (TE-115, patent biological deposit center deposited, deposit date February 20, 2006, deposit number FERM ABP-10529) ). Another type is a strain exhibiting oil-degradability of Achromobacter xylosoxidans, which is also a Gram-negative bacilli (TE-63, deposited at the Patent Biodeposition Center, deposited on February 20, 2006, deposited number FERM ABP-10528). ). Furthermore, another type is a strain showing oil-degradability of Pasteurella multocida, which is also a Gram-negative bacilli (TE-127, patent biological deposit center deposited, deposit date February 20, 2006, deposit number FERM ABP- 10530). The fungal group consisting of this fungal group name TE-1 (a group of bacteria deposited with a third-party organization) is a fungal group that has been collected from a used water-soluble processing liquid at a factory site.

  The bacteria group consisting of this fungal group name TE-1 (group of bacteria deposited with a third party organization) is not accepted by the National Institute of Advanced Industrial Science and Technology patent biological deposit center (date of acceptance rejection certificate issued in 2005) As a group of bacteria deposited with a third-party organization, it is stored in the health room of Tottori Prefectural Institute of Public Health. Those who wish to distribute the fungal group consisting of this fungal group name TE-1 (deposited bacterial group to a third-party organization) contact the Ishida Director of the Sanitation Office of Tottori Prefectural Institute of Public Health. Can receive. Tottori Prefectural Institute for Hygiene and Environment Contact: Address: 526-1 Minamiya, Yurihama-cho, Tohaku-gun, Tottori Prefecture 682-0704, TEL: 0858-35-5411, FAX: 0858-35-5413, Mail: eiseikenkyu @ pref . tottori. jp.

  The oil-containing wastewater may contain mineral oil. In this case, the oil-decomposing microorganism uses a microorganism that decomposes mineral oil. In addition, it has been confirmed by the present inventors that the bacterial group consisting of the above-mentioned bacterial group name TE-1 (self-deposited bacterial group) has a property of decomposing mineral oil, as will be described later.

  The oil-containing waste water may include an emulsion containing water and a water-soluble oil agent. The biological activated carbon may include oil-degrading microorganisms and activated carbon supporting the oil-degrading microorganisms. However, the microorganisms supported on the biological activated carbon may be ordinary microorganisms that are not oil-degradable microorganisms. Oil has already been degraded to some extent by oil-degrading microorganisms, and efficient wastewater treatment is possible even by treatment with normal activated carbon carrying microorganisms.

  The treatment with the microorganism may be performed under anaerobic conditions at 37 ° C. or higher. According to these conditions, the inventors confirmed that the bacteria group consisting of the above-mentioned bacteria group name TE-1 (self-deposited bacteria group) grows well and the oil degradability is improved, as will be described later. is doing.

  About said fungal group, it is an additive used in order to process a water-soluble processing liquid, Comprising: It is used with the form as an additive containing the microorganisms containing said fungal group, and the nutrient culture medium of this microorganism. it can. That is, such an additive can be used in a step of treating a water-soluble processing liquid with an oil-degradable microorganism.

FIG. 1 is a flowchart for explaining a water resource recovery method according to the embodiment.
In the water resource recovery method according to the embodiment, first, a used water-soluble processing liquid is recovered (S102). Next, chips, sludge, other types of oil other than mineral oil, and the like are separated from the used water-soluble processing liquid (S104).

  Next, as a pretreatment, the oil is decomposed by microorganisms to destabilize the emulsion in the used water-soluble processing liquid (S106). Then, an oil coagulant that solidifies the mineral oil into a gel is put into the used water-soluble processing liquid, and the oil component is roughly separated (S108). At this time, the solidified product is filtered through a mesh or the like to separate and remove the solid component (S110).

  Subsequently, the used water-soluble processing liquid that has undergone the rough separation treatment of the oil component is subjected to biological activated carbon treatment (S112). Thereafter, the water obtained by the biological activated carbon treatment is recovered (S114). At this time, according to Example 1 described later, the moisture recovery rate is 90% or more. Further, the remaining oil content of the water-soluble processing liquid is fixed to activated carbon that is solid (S116).

  FIG. 2 is a photomicrograph of an oil-degrading microorganism used in the water resource recovery method according to the embodiment. Thus, the Gram-negative bacilli included in the bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group) has a rod-like shape with a length of several μm (often about 2 to 3 μm).

  FIG. 3 is a conceptual diagram schematically illustrating the configuration of the water resource recovery system according to the embodiment. In this water resource recovery system 1000 (oil-containing wastewater treatment apparatus), an operator 101 operates a cutting machine 102 such as an NC lathe to process a metal part 104 such as a piston. In processing the metal part 104, a water-soluble processing liquid 106 containing an o / w (oil-in-water) type emulsion is used as a cutting oil in order to improve processing accuracy and operability.

  The water-soluble processing liquid 106 scattered when processing the metal part 104 falls on the floor 108 at the site and forms a liquid pool. The pool of the water-soluble processing liquid 106 flows into the waste liquid tank 112 through the drain pipe 110 provided at a low part of the floor surface 108. In addition, meshes are provided at the upper and lower openings of the drain pipe 110 to suppress mixing of chips, sludge, metal parts, and the like.

  In the waste liquid tank 112, the inflowing water-soluble processing liquid 114 is accumulated. The water-soluble processing liquid 114 stored in the waste liquid tank 112 contains a large number of aggregates 116 (fine droplets) of the mineral oil agent, and forms an emulsion as a whole. In addition, solids 118 such as chips, sludge, and metal parts are precipitated at the bottom of the waste liquid tank 112.

  The water-soluble processing liquid 114 in the waste liquid tank 112 flows into the microorganism processing tank 122 through the communication pipe 120. In addition, the mesh is provided in the opening part before and behind the communicating pipe | tube 120, and mixing of the solid substances 118, such as a chip, sludge, a metal component, is suppressed. In the microbial treatment tank 122, the inflowing water-soluble processing liquid 124 is accumulated. The inside of the microorganism treatment tank 122 is controlled to an anaerobic condition at a temperature of 37 ° C. or higher. The water-soluble processing liquid 124 accumulated in the microbial treatment tank 122 contains an aggregate 128 (fine droplets) of a mineral oil agent, and forms an emulsion as a whole. In addition, the water-soluble processing liquid 124 includes a bacterial group 130 composed of the bacterial group name TE-1 (self-deposited bacterial group). The fungus group 130 decomposes the aggregate 128 (fine droplets) of the mineral oil agent and destabilizes the emulsion. As a result, a separated oil layer 126 is formed on the upper layer of the water-soluble processing liquid 124.

  The water-soluble processing liquid 124 in the microorganism treatment tank 122 flows into the oil coagulation removal tank 134 through the communication pipe 132. Note that meshes are provided in the upper and lower openings of the communication tube 132 to suppress mixing of solids such as chips, sludge, and metal parts. In the oil coagulation / removal tank 134, the inflowing water-soluble processing liquid 136 is accumulated. An oil coagulant storage tank 140 is attached to the oil coagulation removal tank 134. The oil coagulant 144 is introduced from the oil coagulant storage tank 140 into the oil coagulation removal tank 134 through the communication pipe 142. The oil component contained in the water-soluble processing liquid 136 accumulated in the oil coagulation removal tank 134 reacts with the oil coagulant 144 to solidify into a gel solid 138, and the liquid layer surface of the oil coagulation removal tank 134 To surface. This is because the oil coagulant 144 is generally lighter than water.

  The water-soluble processing liquid 136 in the oil coagulation removal tank 134 flows into the biological activated carbon treatment tank 148 through the communication pipe 146. In addition, meshes are provided in the front and rear openings of the communication pipe 146, and the gel-like solid matter 138 such as a solidified product obtained by a reaction between the oil component contained in the soluble processing liquid 136 and the oil coagulant 144 is provided. Mixing is suppressed. The biological activated carbon treatment tank 148 is filled with biological activated carbon 150. The biological activated carbon 150 includes a bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group) and activated carbon carrying the bacterial group 130. The water-soluble processing liquid 136 that has flowed into the biological activated carbon treatment tank 148 passes through the biological activated carbon 150, whereby the oil and organic matter are decomposed by the bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group). Oil and organic matter are hydrophobically adsorbed on the pore surface. Therefore, when the water-soluble processing liquid 136 passes through the biological activated carbon 150, BOD and COD are remarkably lowered, and the water-soluble processing liquid 136 becomes a clear drainage that is lower than the drainage standard value.

  The clear drainage flows into the clear drainage tank 154 through the communication pipe 152. Note that meshes are provided in the upper and lower openings of the communication pipe 152 to prevent the biological activated carbon 150 from being mixed. The clear drainage 156 accumulated in the clear drainage tank 154 is inspected whether or not each inspection item below the drainage standard set by the ordinance is cleared. If drainage is permitted as a result of the inspection, the clear drainage 156 in the clear drainage tank 154 is discharged to the river 160 outside the factory via the drainage pipe 158. Note that a mesh is provided at the front and rear openings of the drain pipe 158 to prevent foreign matters from entering the factory.

  The clear drainage 156 released into the river in this way has cleared each inspection item below the drainage standard set by the ordinance and the like, and thus hardly adversely affects natural creatures such as humans 162 and fish 164. Therefore, the clear drainage 156 discharged into the river hardly contaminates the environment.

  In addition, although said process was described as a process by the continuous process on account of description, it does not specifically limit to a continuous process. For example, the same effects can be obtained even if individual unit operations are performed by batch processing.

<Embodiment 2>
The present embodiment relates to a recycling method and a recycling apparatus for used water-soluble machining fluid after using a water-soluble oil such as a water-soluble cutting fluid. Note that points not particularly described in the present embodiment are the same as those in the first embodiment.

  The method for recycling a used water-soluble processing fluid according to the present embodiment is a method of treating a used water-soluble processing fluid containing mineral oil with an oil-degrading microorganism belonging to the genus Pseudomonas at 37 ° C. to 60 ° C. under anaerobic conditions. Including the steps of: As an oil-degrading microorganism belonging to the genus Pseudomonas, for example, a strain exhibiting oil-degrading properties among Pseudomonas aeruginosa (TE-115, patent biological deposit center deposited, deposited date February 20, 2006, deposit number FERM ABP-10529) Etc. can be used suitably.

  At this time, the temperature condition when the water-soluble processing liquid is treated with the oil-degrading microorganism is 37 ° C. or higher, preferably 40 ° C. or higher, particularly preferably 45 ° C. or higher. Moreover, this temperature condition is 60 degrees C or less, Preferably it is 55 degrees C or less. If this temperature condition is at least the above-mentioned lower limit, the speed of destabilization of the emulsion in the water-soluble processing liquid by the oil-degradable microorganism (oil decomposition speed) is improved. On the other hand, when the temperature condition is not more than the above upper limit, the rate of decrease in the number of oil-degradable microorganisms in the water-soluble processing liquid can be suppressed.

  In addition, the recycling method of the used water-soluble processing liquid is obtained by treating the used water-soluble processing liquid that has been treated with microorganisms with an oil coagulant that coagulates mineral oil in a gel state. A step of coagulating and removing the oil agent at least partially. Further, the recycling method of the used water-soluble processing liquid is a biological activated carbon comprising an oil-degrading microorganism belonging to the genus Pseudomonas and an activated carbon carrying the oil-degrading microorganism. The processing step is included.

  In addition, the method for recycling the used water-soluble processing liquid may be executed by batch processing. This batch processing is advantageous in terms of energy consumption because only a small amount of water is used and the process time for heating the water to keep it at 37 ° C. or more and 60 ° C. or less can be shortened. . In addition, although the recycling method of this used water-soluble processing liquid is disadvantageous in terms of energy as compared with batch processing, it may be performed by continuous processing.

  Furthermore, the step of treating with the above-mentioned oil-degrading microorganisms comprises the step of sterilizing the oil-degrading microorganisms of the genus Pseudomonas in a used aqueous processing solution so as to have a concentration of 1 × 10 5 cells / ml or more. May be included. At this time, the concentration of the oil-degrading microorganism is 1 × 10 5 cells / ml or more, preferably 1 × 10 6 cells / ml or more, particularly preferably 1 × 10 7 cells / ml. More than ml. When the concentration of this oil-degrading microorganism is above these lower limits, the rate of destabilization of the emulsion in the water-soluble processing liquid by the oil-degrading microorganism (oil decomposition rate) is improved.

  In the second embodiment, the oil-degrading microorganism belonging to the genus Pseudomonas is used. However, the present invention is not particularly limited to the genus Pseudomonas, and an oil-degrading microorganism belonging to the genus Achromobacter or Pasteurella can be used as well. In this case, as an oil-degrading microorganism belonging to the genus Achromobacter, for example, Achromobacter xylosoxidans strains exhibiting oil-degradability (TE-63, patent biological deposit center deposited, deposit date February 20, 2006, deposit number FERM ABP- 10528) can be preferably used. In addition, as an oil-degrading microorganism belonging to the genus Pasteurella, for example, a strain showing the oil-degradability of Pasteurella multocida (TE-127, patent biological deposit center deposited, February 20, 2006, deposit number FERM ABP-10530) ) And the like can be suitably used.

  Hereinafter, the principle that oil can be efficiently separated from the water-soluble processing liquid by the water resource recovery method according to Embodiments 1 and 2 will be described with reference to the drawings, while referring to the background of the research that led to the completion of the invention. To do. The following phenomena are all phenomena that the present inventors have found for the first time.

  FIG. 4 is a diagram illustrating a state in which a used water-soluble release agent for hot forging is kept in a temperature-raised state for several days in a container to generate microorganisms in the water resource recovery system according to the embodiment. When the used water-soluble mold release agent for hot forging shown in the left bottle of FIG. 4 is kept in a temperature-raised state for several days in the container, the graphite in the mold release agent is changed as shown in the right bottle of FIG. Microorganisms that precipitate and give off an irritating odor are generated in the aqueous phase.

  The present inventor examined the microorganism, and added the microorganism generated in the mold release agent to the oil-containing wastewater such as a water-soluble processing liquid and kept it in a temperature rising state for several days in the container, as will be described later. In addition, it has been found that the oil in the wastewater cannot form a stable emulsion. That is, the present inventor found that emulsion breakage occurred. Furthermore, the present inventor is able to easily adsorb and remove the oil content in the oil-containing wastewater that has caused emulsion breakage by microorganisms without adjusting the pH and temperature by introducing a mineral oil gelling coagulant mainly composed of a polymer. I found.

  Further, the present inventor has found that a water phase that can be drained to a general sewer can be obtained by subjecting the waste water from which the oil content has been adsorbed and removed by the mineral oil gelling coagulant to the activated carbon treatment at room temperature. Furthermore, when this inventor investigated this microorganism, it discovered that the fungus group which consists of said fungus group name TE-1 (self-deposited fungus group) was included.

  FIG. 5 is a diagram illustrating a change in the solution when the water-soluble processing liquid containing microorganisms is maintained in a temperature-up state in the water resource recovery system according to the embodiment. In this experiment, a few drops of the microorganisms that were generated by keeping the used water-soluble mold release agent for hot forging in a container at an elevated temperature in a 20-fold dilution of an emulsion-type water-soluble processing liquid together with the aqueous phase. It was. Then, the water-soluble processing liquid containing microorganisms was put on the hot plate adjusted to 40 degreeC, and was hold | maintained in the state which enclosed the hot plate with the acrylic container.

  FIG. 5 shows how the water-soluble processing liquid containing microorganisms changes. By keeping the temperature elevated, the color of the machining fluid changed from white to pale yellow to white, and the transparency of the machining fluid that changed to white after passing through pale yellow was clearly deteriorated compared to the initial machining fluid. The common cause of deterioration in the transparency of emulsion water is that the emulsion diameter becomes large and the emulsion becomes unstable. Obviously, the added microorganism has the ability to destabilize the emulsion in the oil-containing wastewater. .

  Moreover, the brown phase which is an oil component isolate | separated in the water surface vicinity of the water-soluble processing liquid kept at the temperature rising state for 14 days, and the microorganisms also had the effect of promoting the oil-water separation of an oil-containing wastewater.

  FIG. 6 shows a solution obtained by removing an oil phase separated near the water surface from a water-soluble processing liquid that has caused emulsion destruction by microorganisms, and an excessive amount of mineral oil gelling coagulant added to the solution, followed by stirring at room temperature for 20 minutes The state of the solution thus obtained is shown. By treating with a mineral oil gelling coagulant, the solution becomes cloudy and changes to a transparent liquid. At the same time, the oily odor of the solution disappeared, and the oil content in the oil-containing wastewater treated with microorganisms by the mineral oil gelling coagulant could be separated and removed.

  FIG. 7 shows the state of the solution after the solution obtained by the microbial treatment and the mineral oil gelling coagulant treatment is passed through the activated carbon column. By passing through the activated carbon column, the solution changed to a colorless and transparent, tasteless and odorless aqueous phase, and oil-water separation of the oil-containing wastewater was achieved.

  FIG. 8 is a diagram illustrating a state of water-soluble cutting oil treatment (pretreatment) by the water resource recovery system according to the embodiment. Thus, when it evaluated by the apparent oil layer ratio, when the microorganisms containing the fungal group which consists of fungal group name TE-1 (self-deposited fungal group) was added, it turned out that oil decomposition is accelerated significantly.

  FIG. 9 is a graph showing that oil decomposition is accelerated when microorganisms are added in the water resource recovery system according to the embodiment. When the experimental results in FIG. 8 are summarized in a graph, in the evaluation based on the apparent oil layer ratio, when a microorganism containing a fungus group consisting of the fungus group name TE-1 (self-deposited fungus group) is added, the oil decomposition is increased 2 to 3 times. I found it accelerated.

  FIG. 10 is a diagram illustrating a state of water-soluble cutting oil treatment (biological activated carbon treatment) by the water resource recovery system according to the embodiment. When the water-soluble processing fluid in which the emulsion obtained by the experiment in FIG. 8 is broken is treated with the oil-absorbing gelling coagulant, the oil is solidified into a gel and floats and separates as shown in FIG. Thereafter, as shown in FIG. 10 (B), when the obtained supernatant is treated with biological activated carbon, a clear drainage is obtained. When water-soluble cutting oil is newly added to the clear waste water, as shown in FIG. 10C, re-emulsification is performed, so that a recyclable water resource metabolism system is established.

  On the other hand, instead of destroying the emulsion with microorganisms, as shown in FIG. 10 (D), a clear drainage can be obtained also when the emulsion is broken with an emulsion breaker (inorganic salt) and then treated with activated carbon. However, the clear drainage obtained by adding the emulsion breaker is hardened. Therefore, even if water-soluble cutting oil is newly added to this clear waste water, it does not re-emulsify and a metabolic system is not established.

  It is a figure which shows the mode of the process (pretreatment) of the water-soluble graphite by the water resource collection | recovery system which concerns on embodiment. A similar pretreatment experiment was conducted using water-soluble graphite instead of the water-soluble cutting oil. At this time, as shown in FIG. 11 (A) to FIG. 11 (E), unlike the case of the above-described water-soluble cutting oil, a microorganism containing a bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group) is used. Even when added, there is no significant difference in appearance.

  FIG. 12 is a diagram showing a state of water-soluble graphite treatment (biological activated carbon treatment) by the water resource recovery system according to the embodiment. A similar biological activated carbon treatment experiment was conducted using water-soluble graphite instead of the water-soluble cutting oil. At this time, as shown in FIG. 12 (A) to FIG. 12 (B), as in the case of the above-described water-soluble cutting oil, a microorganism containing a bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group) In other cases, the clarification of the waste water after the biological activated carbon treatment was remarkably improved.

  Hereinafter, the effect of the water resource recovery system of Embodiment 1 and 2 is demonstrated.

  In the water resource recovery system of the embodiment, as shown in FIG. 12 (C), the water quality analysis result of the aqueous phase obtained by processing with a combination of microorganisms having oil decomposability, mineral oil gelling coagulant and activated carbon, The water quality of the obtained clear drainage was water that could be drained sufficiently. That is, according to the water resource recovery system of the embodiment, there is obtained a method of breaking the emulsion without requiring pH adjustment of the oil-containing wastewater and complicated temperature control, and efficiently separating the oil to a reference value level capable of draining. be able to.

  Similarly, with regard to the water resource recovery method of the embodiment, as shown in FIG. 12C, the obtained water phase water quality analysis result clears the drainage standard value for all analysis items. In other words, the oil-containing wastewater treatment method that combines oil-degradable microorganisms, mineral oil gelling coagulant, and activated carbon breaks the emulsion without requiring pH adjustment of the wastewater and complicated temperature control, and it can be drained at a reference level. It has the ability to efficiently separate oil. Therefore, the water resource recovery method of the embodiment can efficiently separate oil by treating oil-containing wastewater by using a combination of microorganisms having oil decomposability and biological activated carbon.

  Similarly, for the bacteria group consisting of the bacteria group name TE-1 (self-deposited bacteria group) used in the water resource recovery system of the embodiment, the results of water quality analysis of the obtained water phase are shown in FIG. As shown, all analysis items cleared the wastewater standard value. In other words, the oil-containing wastewater treatment method that combines the microorganisms including the bacteria group consisting of the bacteria group name TE-1 (self-deposited bacteria group), the mineral oil gelling coagulant and the activated carbon requires pH adjustment of the wastewater and complicated temperature management. Without breaking the emulsion, it has the ability to efficiently separate the oil to a reference level that can be drained. Therefore, the fungus group consisting of the fungus group name TE-1 (self-deposited fungus group) is a technology for efficiently separating oil by treating oil-containing wastewater by using a combination of oil-degradable microorganisms and biological activated carbon. It can be used suitably.

  And the microorganisms required for this method can be obtained by keeping the used water-soluble mold release agent for hot forging in a container at a raised temperature for several days, as shown by the above experimental data. That is, the oil-degrading microorganisms used in the water resource recovery system of the embodiment are not limited to microorganisms including the bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group), and other obtained by the above method It may be a kind of oil-degrading microorganism. This is because oil-degradable microorganisms can decompose the oil agent and destabilize the emulsion in the same manner as the microorganisms containing the bacterial group consisting of the bacterial group name TE-1 (self-deposited bacterial group).

  In addition, according to the present embodiment, it is possible to reduce the COD and n-hexane value concentration in the treated water, which has been difficult to achieve by the conventional treatment method, to the level of the drainage standard value or less, In particular, it is expected to be widely used as a purification method for wastewater containing mineral oil.

  Furthermore, according to the present embodiment, since the emulsion breaker such as aluminum chloride or magnesium chloride, which has been widely used for the treatment of conventional emulsion water, is not used, the treated water is not hardened, and the treatment obtained by the method of the present invention. Water can be used sufficiently as a diluting solution for water-soluble processing fluids, and can be expected from the viewpoint of water resource protection.

  Further, according to the present embodiment, the used water-soluble processing liquid is treated with oil-degradable microorganisms at 37 ° C. to 60 ° C. under anaerobic conditions to destabilize the emulsion in the used water-soluble processing liquid. be able to. As a result, by treating the mineral oil with an oil coagulant that coagulates in a gel state, a part of the emulsion destabilized by the oil-degradable microorganisms can be coagulated and removed. Then, by removing the remaining emulsion by adsorption using biological activated carbon containing oil-degrading microorganisms, it is possible to efficiently separate the oil and recycle the used water-soluble processing liquid.

  Furthermore, according to the present embodiment, the used water-soluble processing liquid is treated with an oil-degradable microorganism under anaerobic conditions at 37 ° C. to 60 ° C., which is a higher temperature condition than normal water treatment. The rate of destabilizing the emulsion in the used aqueous processing liquid (oil decomposition rate) can be improved.

  In the conventional high-temperature water treatment method such as the shaft method, treatment using microorganisms is not performed, so that the operational effects as in this embodiment cannot be obtained. That is, since this embodiment uses oil-degrading microorganisms that exhibit oil-decomposing activity under higher temperature conditions than ordinary water treatment at 37 ° C. or higher and 60 ° C. or lower, This is particularly effective in the recycling treatment of used water-soluble processing liquids, which are difficult to recycle and easily form a stable emulsion.

  On the other hand, FIG. 22 is a conceptual diagram schematically showing a state of a manufacturing site where a used water-soluble processing liquid is generated. As shown schematically in this figure, environmental and safety issues are the world's highest priority at the cutting site for metal products in factories, so "oil" is one of the points in the production and processing field. , Requests to suppress oil splatter during work, requests to reduce the risk of ignition, requests to suppress the discharge of sludge containing oil, waste oil treatment (extreme pressure additives (P, S), including chlorine, etc.) ), And there is a strong demand for reducing the amount of waste oil generated (about 1% of industrial waste (about 4 million tons per year in Japan)). For this reason, as a global trend, the amount of water-soluble machining fluid used is expected to increase.

  FIG. 23 is a conceptual diagram for explaining that the environmental load is large when used water-soluble machining fluid is processed by a combustion method. When used water-soluble machining fluid is treated by the combustion method, it tends to be incompletely combusted due to the high water content. For this reason, nitrogen oxides, sulfur oxides, dioxins and the like are likely to be generated, and the environmental load during waste liquid treatment is large.

  FIG. 24 is a diagram for explaining that it is difficult to clear the effluent regulation value when used aqueous processing liquid is processed by the coagulation sedimentation method. Hideki Yasui, “Story of oil technology useful in the field”, Mechanical Technology, 2003, p. 82-83. When used water-soluble processing fluid is processed by the coagulation sedimentation method, the process is complicated and it is difficult to clear the drainage regulation value.

  In contrast, the water resource recovery system of the embodiment can be said to be a system that recovers water resources from the processing liquid by a simple method and discharges only oil that is a waste product out of the system. Problems that are difficult to solve by the precipitation method can be easily solved.

  As mentioned above, although embodiment of this invention was described with reference to drawings, these are the illustrations of this invention, Various structures other than the above are also employable.

  For example, in the above-described embodiment, the oil-containing wastewater treatment device is provided at the lower part of the floor of the factory, but may be configured on a movable transport vehicle. In this way, it is possible to visit the factories several times a year and treat the accumulated oil-containing wastewater together, so that the capital investment cost can be significantly reduced and the operating rate of the oil-containing wastewater treatment equipment The advantage that can be improved is obtained.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further, this invention is not limited to these.

<Example 1>
1. Introduction In order to achieve the three major goals of machining, “high quality, high efficiency, and low cost”, users have used a large amount of machining fluid. However, various chemical substances are mixed in the working fluid, which not only impairs the health of workers but also causes environmental pollution. In recent years, the use of a large amount of machining fluid has been restricted due to the enforcement of the PRTR law and waste fluid treatment, and the next generation of innovative machining technology / It can be said that it is difficult to realize a machine tool.

  As countermeasures against these problems, various environmentally friendly processing methods have been proposed, and dry processing, ultra-low-volume lubrication methods that process by supplying a small amount of processing fluid, synthetic coolants that do not contain any mineral oil components, etc. are being put into practical use. . However, these methods have advantages and disadvantages, and if all processing is replaced with these methods, production efficiency and processing quality are deteriorated.

  In this example, focusing on the water-soluble machining fluid that is expected to occupy the central position of the machining fluid in the current, short and medium-term future, only the oil component in the water-soluble machining fluid introduced into the machine tool is focused. Periodic separation, removal, and renewal, outline the “water-soluble processing fluid metabolism system” that circulates and occupies most of the water in the process, and recovers water resources from water-soluble processing fluid using biological activated carbon Report on the system.

2. Water-Soluble Processing Fluid Metabolism System FIG. 13 shows a schematic configuration of a “water-soluble processing fluid metabolism system” which the present inventors have studied. The water-soluble processing fluid must be periodically replaced because the oil component deteriorates by oxidation and other oils, sludge, etc. are mixed and deteriorated in performance. Currently, it is common to dispose of the entire amount of used machining fluid generated at the time of replacement. However, with this method, it is necessary to treat up to 90% of the volume of the machining fluid as industrial waste. is there.

  On the other hand, as shown in FIG. 13, among the used water-soluble processing fluid, only the deteriorated oil agent and other oils / sludge etc. corresponding to the waste are separated and removed, and the water is reused as a diluent for the processing fluid to be renewed. If a metabolic system can be established, the amount of waste generated will be greatly reduced. In addition, when considering the balance of input and output of substances in this metabolic system, ignoring other oils, sludge, evaporated water, etc. that are mixed during processing, only the oil component comes in and out, and as a result, a small amount of oil agent is removed for a certain period of time. It becomes a processing system that circulates.

  FIG. 14 is a comparison of the amount of oil used in a processing system incorporating a very small amount of lubricating oil (MQL) processing and a water-soluble processing fluid metabolism system. The trial calculation was performed on the assumption that the amount of oil used in MQL processing was 10 ml / hr, and in processing with a water-soluble processing liquid, a 15-fold diluted processing liquid was used with a machine tool having a 200 L scale circulation tank.

  In MQL processing, the amount of oil used increases in proportion to the processing time because the oil is used once through. When the processing fluid is circulated and used for about 1300 hours in a processing system in which a metabolic system is introduced, the input and output of both oils appear to be apparent. The output amount matches. That is, when a metabolic system is introduced, a processing system with a minute oil consumption comparable to MQL processing is realized without changing the conventional processing method.

3. Water Resource Recovery System Utilizing Biological Activated Carbon 3.1 Flow of Water Resource Recovery System FIG. 15 shows a schematic flow of the water resource recovery system being developed by the present inventors. Add microorganisms capable of degrading the emulsified oil to the used water-soluble processing liquid and leave it for about 1 to 2 weeks. At this time, it is not necessary to adjust the pH of the working fluid, and precise temperature adjustment is also unnecessary. Then, the emulsion becomes unstable due to the action of microorganisms, and many oils can be easily separated by a general oil recovery method.

  Thereafter, when the processing liquid is treated by the biological activated carbon method using the same microorganism, the remaining oil component is adsorbed on the activated carbon, and the oil-free water can be recovered at a recovery rate of 90% or more. Here, the biological activated carbon method is a method in which microorganisms are attached to the activated carbon surface, and the activated carbon surface is simultaneously adsorbed by the activated carbon and decomposed by the microorganisms to extend the lifetime of the activated carbon, and is widely used in the field of water treatment.

3.2 Examples of water resource recovery (1) Example of processing water-soluble graphite for hot forging Water-soluble graphite is used as a release agent in hot forging, and graphite particles are dispersed in so-called emulsion water. FIG. 16 shows the state of the working fluid when a pretreatment is performed by introducing microorganisms into used water-soluble graphite provided from a forging factory in Tottori Prefecture. Most of the graphite dispersed in the liquid by the pre-treatment floats or settles and the oil component is further decomposed, and the liquid phase becomes transparent. When the graphite component was separated from this liquid, a greenish aqueous phase was obtained, and when this was treated with biological activated carbon, colorless and odorless water resources could be recovered.

  Water quality analysis of the recovered aqueous phase revealed that BOD: 3.4 mg / L, COD: 9.1 mg / L, n-hexane: <0.5 mg / L, and the recovered water can be drained The water quality was excellent. The release agent using the recovered water as a diluent had the same performance as the virgin release agent as described in Example 2 described later.

(2) Treatment Example of Water-Soluble Cutting Oil A test similar to that of water-soluble graphite was performed on a chlorine-containing emulsion type water-soluble cutting oil used for about one year at a practical factory of Yonago National College of Technology. As a comparative experiment, a spent processing solution without microorganisms was also examined. FIG. 17A shows the state of the processing liquid after leaving the microorganisms for 2 days and 14 days.

  In the sample to which microorganisms were added, a phase considered to be an oil phase started to separate on the liquid surface around one day after the addition, and the thickness of the separated phase increased with the number of days left. This separation phase was also found in samples without added microorganisms.

  This is because in this test, the processing liquid was kept slightly higher than room temperature for the purpose of accelerating the treatment effect of microorganisms, so that the microorganisms naturally generated in the processing liquid during one year of use This is thought to be due to the promotion of decomposition.

  However, as shown in FIG. 18, the separation rate of the oil phase is significantly faster in the sample to which the microorganism was added, and the microorganism used in this study has a higher ability to decompose the emulsified oil. I understand that.

  FIG. 17B shows the state of the aqueous phase obtained by performing biological activated carbon treatment after pretreatment with microorganisms. FIG. 17B also shows the state of the aqueous phase obtained using the emulsion breaker. There is no difference in the apparent transparency of the recovered water phase between the two treatments, but when water-soluble cutting fluid is added to these reclaimed water again, emulsion water is formed in the treated water by the emulsion breaker due to hardening. In contrast, microbial treatment forms emulsion water and achieves a metabolic system.

4). Summary When using the biological activated carbon method, water can be recovered from the processing liquid at a recovery rate of 90% or more without adjusting the pH and precise temperature. With this metabolic system, there is a possibility that a processing system with a minute oil consumption amount comparable to MQL processing can be realized without changing the conventional processing method.

<Example 2>
1. INTRODUCTION Interest in environmental issues has been increasing rapidly in recent years, and environmental impacts have been required for corporate production activities. Particularly in the field of machining, there are problems of deterioration of the working environment due to the use of machining fluids such as cutting fluids and grinding fluids, and environmental burden due to disposal of the machining fluid. For this reason, it is said that the processing liquid used in machining tends to shift from water-insoluble to water-soluble, and even water-soluble processing liquid tends to shift from emulsion type to soluble and solution type (Non-Patent Document 1). .

  One of the problems with water-soluble processing liquids is waste liquid treatment. Examples of the waste liquid treatment method for water-soluble processing fluid include an incineration method and a coagulation sedimentation method (Non-patent Document 2).

  The former has been pointed out to be polluted by nitrogen oxides, sulfur oxides, carbon dioxide, etc. generated during incineration. In addition, for the latter, it takes a lot of labor and time to process the used machining fluid to a level at which it can be drained. For this reason, the processing of the water-soluble processing liquid generated at business establishments costs about several tens of yen per liter, which increases the processing cost.

  In order to reduce the environmental load and processing cost by suppressing the amount of water-soluble processing fluid used, research on dry processing and semi-dry processing is also being conducted extensively. However, there are still problems in introducing these processing methods into actual production processing sites, and at present, they have not been replaced with water-soluble processing liquids.

  Therefore, the present inventors separated and removed only the oil component in the water-soluble processing liquid in order to reduce the environmental load and processing cost in the disposal of the water-soluble processing liquid, and the water occupying most of the volume is in the process. We considered a “water-soluble processing fluid metabolism system” for recycling in Japan.

  In order to realize a water-soluble processing fluid metabolism system, it is necessary to be able to process a large amount of waste liquid at a low cost and to reuse the water separated and recovered from the waste liquid without any problems. In this example, a large amount of waste liquid treatment using the water separation method described in Example 1 described above, and the basic performance of the processing liquid using the obtained reclaimed water as a diluent were examined.

2. 2.1 Possibility of establishing a water-soluble processing fluid metabolism system 2.1 Mass treatment of used processing fluid by biological activated carbon method Whether the biological activated carbon treatment method described in Example 1 above is applicable to treatment of a large amount of water-soluble processing fluid investigated. The processing target is an emulsion-type water-soluble cutting fluid containing a chlorine component that has been used at a machining center for about one year, and the processing amount is about 20 liters per batch. FIG. 19 shows the process. Microorganisms were added to the water-soluble cutting fluid and allowed to stand for about 2 weeks, and then the oil was roughly separated using a general method for separating oil components. After that, when the biological activated carbon treatment was performed, the water containing no oil component could be separated.

  Although it depends on the filtration method, the time from the rough separation of the oil agent component to the biological activated carbon treatment to obtain reclaimed water for the cutting fluid after the microbial treatment is about several hours. The water recovery rate was 90% or more. The processing cost was about 30 yen per liter. The processing time and the processing cost can be reduced by improving the processing method and the effect of mass processing.

  Up to now, the present inventors have not only used the emulsion-type water-soluble cutting fluid shown in FIG. 19 but also used a water-soluble graphite release agent for hot forging, a soluble type and a solution-type water-soluble cutting fluid. Moisture recovery is performed by activated carbon treatment, and its effectiveness has been confirmed in any working fluid.

2.2 Evaluation of basic performance of processing fluid using reclaimed water as a diluent The water-soluble processing fluid metabolism system is considering using reclaimed water obtained by biological activated carbon treatment as a diluent for water-soluble processing fluid. In order to develop a water-soluble working fluid metabolism system, it is necessary to study the processing performance of a water-soluble working fluid obtained using regenerated water as a diluent.

  Therefore, the present inventors conducted a performance evaluation test in order to investigate the basic performance of the water-soluble graphite release agent for hot forging and the emulsion-type water-soluble cutting fluid using recycled water as a diluent.

2.2.1 Basic performance of water-soluble graphite release agent for hot forging using reclaimed water as diluent (1) Water-soluble graphite release agent for hot forging using reclaimed water as diluent When a water-soluble graphite release agent was newly prepared using the reclaimed water obtained by the treatment as a diluent, an emulsion state could be obtained without any problem. There was no difference in appearance between tap water as diluent and reclaimed water as diluent. Further, no change in quality was observed even when the release agent using regenerated water as a diluent was allowed to stand at room temperature for 2 months or longer. The water-soluble graphite used was Pro-Height S35 made by Nippon Graphite, and the dilution factor was 15 times.

(2) Adhesion test Adhesion to a test piece was examined for one obtained by diluting water-soluble graphite with tap water and one diluted with regenerated water obtained by treating a used processing liquid with biological activated carbon. As the test piece, a S45C plate material having a thickness of 2 mm cut into a 40 × 50 mm square was used. The surface on which the water-soluble graphite was adhered was wet-polished with # 320 emery paper to obtain the same degree of surface ancestry as an actual forging die, and then washed with acetone.

  After leaving the test piece on a hot plate heated to 100 ° C., 125 ° C., and 150 ° C. for 20 minutes, water-soluble graphite was sprayed by hand spraying. The adhesion state of the water-soluble graphite after spraying was visually observed.

  FIG. 20 shows the state of adhesion of water-soluble graphite at room temperature and at each heating temperature. At any heating temperature, there was no difference in adhesion between the case of using tap water as the diluent and the case of using reclaimed water.

(3) Measurement of friction coefficient by ring compression test In order to investigate the friction coefficient of water-soluble graphite mold release agent using tap water and reclaimed water as diluents, a ring compression test was conducted. Using the experimental results obtained from the compression test as boundary conditions, a commercially available three-dimensional rigid-plastic finite element method forging simulator, DEFORM-3D, can be used between a compressor tool and a ring surface to which a water-soluble graphite mold release agent is attached. The friction coefficient was obtained (Koji Yamada et al., 5 people, research on mold design support system using general-purpose simulation software, JSME lecture papers No. 045-1 (2004), 17-18).

  FIG. 21 shows the friction coefficient of the water-soluble graphite mold release agent obtained by the ring compression test using tap water and reclaimed water as diluents. In addition, since the measured value of the friction coefficient varied somewhat depending on the measurement points on the ring test piece, FIG. 21 shows the maximum value and the minimum value of the friction coefficient. When tap water was used as the diluent and when reclaimed water was used, there was no significant difference in the friction coefficient between the two.

2.2.2 Basic performance of water-soluble cutting fluid with reclaimed water as diluent (1) Water-soluble cutting fluid with reclaimed water as diluent Obtained by treating bio-activated carbon with used emulsion-type water-soluble cutting fluid A water-soluble cutting fluid was newly prepared using recycled water as a diluent. The appearance of the obtained water-soluble cutting fluid was the same as when tap water was used as a diluent. In addition, no change in appearance was observed even when left at room temperature for 1 month or longer.

(2) Machining test The machining test for examining the machining performance of water-soluble cutting fluid using reclaimed water as a diluent was decided to be done by drilling. 100 holes were drilled with a high-speed drill with a diameter of 8 mm to measure tool wear and cutting force. The work material was an S45C plate, the hole depth was 25 mm, and the cutting speed was 50 m / min. The cutting fluid was externally supplied by an oil supply pump. As a result, no obvious difference was found in the amount of tool wear and the cutting force in the range where 100 holes were drilled between machining fluids containing recycled water and tap water as diluents.

3. Conclusion As a basis for the development of a “water-soluble processing fluid metabolism system” aimed at reducing the environmental impact and processing costs in the disposal of water-soluble processing fluids, mass processing of used water-soluble processing fluids and reuse of separated water The possibility was examined.

  The biological activated carbon treatment method developed by the present inventors can be applied to a large amount of oil agent treatment, and the treatment cost can be made equal to or less than the current disposal cost. In addition, when water-soluble graphite used as a release agent for hot forging was investigated, biological activated carbon treatment was used as a diluent for water-soluble graphite release agent in both the adhesion test and the friction coefficient measurement by ring compression test. The basic performance as a release agent did not change even when the reclaimed water obtained by the above method was used. This also applies to the water-soluble cutting fluid, and suggests that the water separated from the used water-soluble machining fluid can be reused in the machining process.

<Example 3>
1. Objective The present inventors conducted experiments by the following test methods in order to examine the water-soluble processing fluid oil separation ability of the bacteria and the bacterial group (TE-1) isolated after three-dimensional culture.

2. Test materials 1) Water-soluble processing fluid (1) Water-soluble processing fluid A: Emulsion type, chlorine-containing (Yanase Seisakusho) diluted 20 times and used.

  (2) Water-soluble processing fluid B: High chip, emulsion type, chlorine-free (Taille Co., Ltd.) diluted 20 times

  (3) Water-soluble processing liquid C: Chemochlor, synthetic type, chlorine / amine-free (Taille Co., Ltd.) diluted 20 times and used.

2) Bacterial group (TE-1)
A water phase (color is green and has an irritating odor. The presence of multiple fungi is confirmed by microscopic observation) from the separated water-soluble graphite (provided by Meiji Seisakusho Co., Ltd.). Using.

3) Inorganic base medium (component composition per liter)
CaCl2 / H2O 34.4mg
MgSO4 · 7H2O 100mg
NH4NO3 10g
Trace element preservation solution A 10ml
Trace element preservation solution B 10μl
0.33M phosphate buffer 10ml

Trace element preservation solution A (component composition per 500 ml)
FeCl2 · 6H2O 1g
MnSO4 · 5H2O 100mg

Trace element preservation solution B (component composition per 100 ml)
CuSO4 · 5H2O 1g
ZnSO4 · 7H2O 1.14g
H3BO3 100mg
NiSO4 · 6H2O 100ml

0.33M phosphate buffer (component composition per 500 ml)
KH2 / PO4 57.2g
K2HPO4 148.2g

4) Ordinary agar medium (component composition per liter)
Polypeptone 10g
5g meat extract
NH4NO3 5g
NaCl 5g
Agar 15g

3. Test Method (1) FIG. 25 is a diagram illustrating a method for isolating microorganisms from the bacterial group TE-1. In this isolation method, first, 100 μl of TE-1 was added to 10 ml of an inorganic salt medium containing 0.5% of water-soluble processing solutions A to C, and primary culture was performed for 14 days in a 37 ° C. incubator. Subsequently, 100 μl of the primary culture solution was added to 10 ml of an inorganic salt medium containing 0.5% of the water-soluble processing solutions A to C, and secondary culture was performed in a 37 ° C. incubator for 14 days. Then, the third culture was performed in the same manner, and the third culture was cultured on ordinary agar and then isolated.

(2) The isolated bacteria were suspended in sterilized distilled water. At this time, the concentration of the bacterial solution was adjusted to 1.0 McFarland.
(3) The bacterial solution of (2) and 0.5 ml of TE-1 were added to 5 ml of water-soluble processing solution B, respectively, and Brix (%) of the water-soluble processing solution was examined.

<Example 4>
1. Objective The present inventors conducted an experiment by the following test method in order to examine the oil separation ability of the isolated fungus.

2. Test Method 0.4 ml of the isolated bacterium (MF1.0) was placed in the water-soluble processing solution B and anaerobically cultured at 40 ° C. Then, after separating the oil, 0.4 ml was further added to a new water-soluble processing solution B and cultured in the same manner for 3 generations. In addition, the Brix value of the water-soluble processing liquid B was measured after each culture.

3. Test result The measurement result of the Brix value of the water-soluble working fluid is shown in Table 1. In addition, the measurement of the following Brix values also including a present Example was measured as Brix (%) with the digital sugar content (concentration) meter (PR-101 (alpha)).

  As shown in Table 1, the oil separation ability decreased as the passage progressed, but all strains showed good oil separation ability until the second generation. That is, a strain exhibiting oil-degradability of Pseudomonas aeruginosa (TE-115, deposited at the Patent Biodeposition Center, deposited date February 20, 2006, deposit number FERM ABP-10529), a strain exhibiting oil-degradability of Achromobacter xylosoxidans (TE-63, patent biological deposit center deposited), deposit date February 20, 2006, deposit number FERM ABP-10528), strain showing oil-degradability of Pasteurella multocida (TE-127, patent biological deposit center deposited) All strains of deposit number FERM ABP-10530) on deposit date February 20, 2006 showed good oil separation ability.

<Example 5>
1. Objective The present inventors conducted an experiment with the following test method in order to examine where the isolated bacteria increased.

2. Test Method Each of the oil layer and the aqueous layer of the water-soluble processing fluid B separated in oil in Example 4 was placed in a new water-soluble processing fluid B, and anaerobic culture was performed at 40 ° C. In addition, the Brix value of the water-soluble processing liquid B was measured after each culture.

3. Test result The measurement result of the Brix value of the water-soluble working fluid is shown in Table 2.

  As shown in Table 2, it was shown that no bacteria were present in the water layer and that the bacteria had migrated to the oil layer. That is, a strain exhibiting oil-degradability of Pseudomonas aeruginosa (TE-115, deposited at the Patent Biodeposition Center, deposited date February 20, 2006, deposit number FERM ABP-10529), a strain exhibiting oil-degradability of Achromobacter xylosoxidans (TE-63, patent biological deposit center deposited), deposit date February 20, 2006, deposit number FERM ABP-10528), strain showing oil-degradability of Pasteurella multocida (TE-127, patent biological deposit center deposited) , Deposit date: February 20, 2006, all strains of deposit number FERM ABP-10530) were transferred to the oil reservoir.

<Example 6>
1. Objective The present inventors conducted an experiment using the test method described above in order to examine the ability of microorganisms to separate water-soluble processing fluid oil depending on the temperature.

2. Test Method Isolated bacteria (3 types) were enriched with BHI broth at 37 ° C. for 24 hours. The three strains used are strains exhibiting oil-degradability of Pseudomonas aeruginosa (TE-115, patent biological deposit center deposited, deposit date February 20, 2006, accession number FERM ABP-10529), Achromobacter xylosoxidans A strain showing oil-degradability (TE-63, deposited at Patent Biodeposition Center, deposited date February 20, 2006, deposit number FERM ABP-10528), a strain showing oil-degradability of Pasteurella multocida (TE-127, The patent biological deposit center was deposited, and the deposit date was February 20, 2006, and the deposit number was FERM ABP-10530).

  Each bacterium was then made into serial dilutions at a concentration of 102 CFU / ml to 108 CFU / ml using distilled water. Then, 0.3 ml of the diluted bacterial solution was added to 2.7 ml of the water-soluble processing solution B, and anaerobic culture was performed at 40 ° C and 50 ° C. Thereafter, the Brix value (%) was measured after 1 day, 3 days, and 7 days.

In this case, the amount of bacteria used is
TE-63 8.0 × 10 2 CFU / ml to 8.0 × 10 6 CFU / ml
TE-115 4.5 × 10 3 CFU / ml to 4.5 × 10 7 CFU / ml
TE-127 4.6 × 10 3 CFU / ml to 4.6 × 10 7 CFU / ml
As an experiment.

3. Test result The measurement result of the Brix value of the water-soluble working fluid is shown in Tables 3 to 5 and FIG.

  As shown in Tables 3 to 5 and FIG. 26, according to the Brix measurement results, in any of the three strains, the culture at 50 ° C. is more brilliant than the culture at 40 ° C. The value was low. Therefore, a strain exhibiting oil-degradability of Pseudomonas aeruginosa (TE-115, deposited at the Patent Biodeposition Center, deposited date February 20, 2006, deposit number FERM ABP-10529), a strain exhibiting oil-degradability of Achromobacter xylosoxidans (TE-63, patent biological deposit center deposited), deposit date February 20, 2006, deposit number FERM ABP-10528), strain showing oil-degradability of Pasteurella multocida (TE-127, patent biological deposit center deposited) In any case of the deposit date, February 20, 2006, deposit number FERM ABP-10530), the oil separation of the water-soluble processing liquid B by microorganisms is more active at 50 ° C. than 40 ° C.

  In the above, this invention was demonstrated based on the Example. It is to be understood by those skilled in the art that this embodiment is merely an example, and that various modifications are possible and that such modifications are within the scope of the present invention.

  For example, in the above examples, water-soluble graphite using reclaimed water as a diluent will be reused in the hot forging process in the future. For example, by using it in another process with lower requirements for water quality, May be used.

  A similar metabolic system can be constructed for various water-soluble cutting fluids including emulsion type. That is, the reclaimed water separated from the used cutting fluid may be used as a diluent, and may be used as a water-soluble cutting fluid for products with lower requirements for processing accuracy.

  As described above, since the method for treating oil-containing wastewater according to the present invention uses a combination of oil-degradable microorganisms and biological activated carbon, the oil-containing wastewater can be treated to effectively separate the oil. It is useful as an oil-containing wastewater treatment method, an oil-containing wastewater treatment device, and the like.

  In addition, since the bacterial group according to the present invention is an oil-decomposable bacterial group, a technique for efficiently separating oil by treating oil-containing wastewater by using a combination of oil-degradable microorganisms and biological activated carbon. It is useful as a fungus group, a microorganism, an additive and the like.

Claims (24)

Treating a used water-soluble working fluid containing mineral oil with an oil-degradable microorganism under anaerobic conditions of 37 ° C. or more and 60 ° C. or less;
Treating the used water-soluble processing liquid that has undergone the treatment with the microorganism with an oil coagulant that coagulates mineral oil in a gel state to coagulate and remove at least a part of the oil in the used water-soluble processing liquid. When,
Treating the used water-soluble processing liquid from which at least a part of the oil agent has been removed with a biological activated carbon composed of the oil-degrading microorganisms and activated carbon carrying the oil-degrading microorganisms;
A method for recycling used water-soluble processing fluid, comprising: The recycling method according to claim 1,
The method for recycling a used water-soluble processing liquid, wherein the oil-degrading microorganism is a microorganism contained in one or more genera selected from the group consisting of the genus Pseudomonas, Achromobacter, and Pasteurella. In the recycling method of the water-soluble processing liquid according to claim 1,
The method for recycling a water-soluble processing liquid, wherein the recycling method is performed by batch processing. In the recycling method of the water-soluble processing liquid according to claim 1,
The step of treating with the oil-degrading microorganism includes the step of gonoculating the oil-degradable microorganism in the used water-soluble processing liquid to a concentration of 1 × 10 5 cells / ml or more. Recycling method of water-soluble processing fluid. In the recycling method of the water-soluble processing liquid according to claim 1,
A method for recycling a water-soluble processing liquid, wherein the used water-soluble processing liquid containing mineral oil includes an emulsion containing water and mineral oil. A microorganism treatment tank for treating a used water-soluble processing fluid containing mineral oil with an oil-degradable microorganism at 37 ° C. or more and 60 ° C. or less under anaerobic conditions;
Oil for treating the used water-soluble processing liquid that has been treated with the microorganism with an oil coagulant that coagulates mineral oil in a gel state to coagulate and remove at least part of the oil in the used water-soluble processing liquid. A coagulation removal tank;
A biological activated carbon treatment tank for treating the used water-soluble processing liquid from which at least a part of the oil agent has been removed with a biological activated carbon comprising the oil-degradable microorganisms and activated carbon supporting the oil-degradable microorganisms;
A recycling apparatus for used water-soluble processing fluid, characterized by comprising: The recycling method according to claim 6,
The used oil-degrading microorganism is a microorganism contained in one or more genera selected from the group consisting of the genus Pseudomonas, Achromobacter, and Pasteurella. Treating oil-containing wastewater with oil-degradable microorganisms;
Treating the oil-containing wastewater treated with the microorganism with biological activated carbon;
An oil-containing wastewater treatment method comprising: Treating oil-containing wastewater with oil-degradable microorganisms;
Treating the oil-containing wastewater that has undergone treatment with the microorganism with an oil coagulant to coagulate and remove at least part of the oil agent in the oil-containing wastewater; and
Treating the oil-containing wastewater from which at least part of the oil has been removed with biological activated carbon;
A method for treating oil-containing wastewater containing water. In the processing method of the oil-containing wastewater of Claim 9,
The oil-containing wastewater contains mineral oil,
The oil coagulant coagulates mineral oil in a gel form. In the processing method of the oil-containing wastewater of Claim 9,
The oil-decomposing microorganism includes a fungus group consisting of a fungus group name TE-1 (a group of bacteria deposited with a third party organization). In the processing method of the oil-containing wastewater of Claim 9,
The method for treating oil-containing wastewater, wherein the oil-degrading microorganism is a microorganism contained in one or more genera selected from the group consisting of the genus Pseudomonas, Achromobacter and Pasteurella. In the processing method of the oil-containing wastewater of Claim 9,
The oil-containing wastewater contains mineral oil,
The oil-decomposing microorganism decomposes mineral oil, and is a method for treating oil-containing wastewater. In the processing method of the oil-containing wastewater of Claim 9,
The oil-containing wastewater includes an emulsion containing water and a water-soluble oil agent. In the processing method of the oil-containing wastewater of Claim 9,
The biological activated carbon includes the oil-decomposing microorganism and the activated carbon carrying the oil-degrading microorganism, and a method for treating oil-containing wastewater. In the processing method of the oil-containing wastewater of Claim 9,
The method for treating oil-containing wastewater, wherein the treatment with microorganisms is performed at 37 ° C. or more under anaerobic conditions. A microorganism treatment tank for treating oil-containing wastewater with oil-degradable microorganisms;
A biological activated carbon treatment tank for treating the oil-containing wastewater treated with the microorganism with biological activated carbon;
An oil-containing wastewater treatment apparatus comprising: A microorganism treatment tank for treating oil-containing wastewater with oil-degradable microorganisms;
An oil coagulation removal tank that treats the oil-containing wastewater that has been treated with the microorganism with an oil coagulant to coagulate and remove at least part of the oil agent in the oil-containing wastewater;
A biological activated carbon treatment tank for treating the oil-containing wastewater from which at least a part of the oil agent has been removed with biological activated carbon;
An oil-containing wastewater treatment apparatus. The oil-containing wastewater treatment apparatus according to claim 18,
The oil coagulant is an oil-containing wastewater treatment apparatus characterized by coagulating mineral oil in a gel form. The oil-containing wastewater treatment apparatus according to claim 18,
The oil-decomposing microorganism comprises a fungus group consisting of a fungus group name TE-1 (a group of bacteria deposited with a third party organization). The oil-containing wastewater treatment apparatus according to claim 18,
The oil-containing wastewater treatment apparatus, wherein the oil-degrading microorganism is a microorganism contained in one or more genera selected from the group consisting of Pseudomonas genus, Achromobacter genus and Pasteurella genus. The oil-containing wastewater treatment apparatus according to claim 18,
An oil-containing wastewater treatment apparatus, wherein the oil-degrading microorganisms decompose mineral oil. The oil-containing wastewater treatment apparatus according to claim 18,
The biological activated carbon includes the oil-decomposing microorganism and the activated carbon supporting the oil-decomposing microorganism, and the oil-containing wastewater treatment apparatus. The oil-containing wastewater treatment apparatus according to claim 18,
The said microorganism treatment tank is comprised so that adjustment to 37 degreeC or more and anaerobic conditions is possible, The processing apparatus of the oil-containing wastewater characterized by the above-mentioned.