High-concentration cutting fluid waste water recycling treatment system and use method thereof

Abstract

The invention discloses a water recycling treatment system for high-concentration cutting fluid waste liquid and a method for using the system, which belongs to the field of wastewater treatment. The system includes a coarse filter, a biological device, a water storage tank, a centrifuge, a silicon carbide membrane filter and a nanofiltration membrane filter in the order of liquid passing under working conditions. The biological device is an upflow biofilm reactor filled with fillers, and the fillers are loaded with microorganisms that have been domesticated to proliferate with cutting fluid waste liquid as a substrate. The invention directly replaces the chemical treatment in the prior art with biological treatment as a pretreatment before membrane filtration, without secondary pollution, and uses the advantage of microorganisms having a high degree of decomposition of organic matter to perform a relatively thorough treatment of the complex organic components in the high-concentration cutting fluid waste liquid, thereby reducing the COD of the cutting fluid waste liquid, greatly alleviating the pollution problem of subsequent membrane treatment, maintaining the high-flux operation of the membrane, and extending the life of the membrane. The effluent can be reused to prepare the cutting fluid working fluid, thereby realizing the reduction and resource treatment of the cutting fluid waste liquid.

Description

Technical Field

[0001] The invention relates to a water recycling treatment system for high-concentration cutting fluid waste and a use method thereof, belonging to the field of wastewater treatment. Background Art

[0002] As the degree of automation in the machining industry increases, the demand for water-based cutting fluids is also gradually increasing. After a certain period of service in an open environment, the cutting fluid will gradually become corrupt and smelly, and it can no longer be used and becomes cutting fluid waste. In addition to a large amount of water, the waste fluid also contains impurities such as metal chips, organic additives, and microorganisms. The composition is complex and difficult to handle. If it is directly discharged, it will pose a great threat to the environment, ecosystems, and human health. The cost of treating cutting fluid waste is high. If the waste fluid can be reduced in advance or even recycled, the cost of treating cutting fluid waste will be greatly reduced.

[0003] The treatment methods for cutting fluid waste are divided into physical method, chemical method and biological method. Among them, physical method is the most commonly used treatment method. For example, membrane filtration has become the mainstream application technology due to its advantages such as high efficiency, easy operation, small footprint and no secondary pollution. However, during use, high-concentration difficult-to-treat substances in cutting fluid waste are prone to membrane pollution, resulting in a rapid decrease in membrane flux, and the COD removal rate of membrane filtration (referring to the proportion of reducing chemical oxygen demand) is limited. Therefore, it is necessary to couple other treatment methods to achieve the result of cost reduction and efficiency improvement for the treatment of high-concentration cutting fluid waste. Traditional combined treatment methods usually use chemical methods as pretreatment before membrane filtration and biological methods as deep treatment after membrane filtration. However, chemical methods require the addition of chemical agents, which consumes a lot of drugs, and a large amount of precipitation will be produced after chemical treatment to become solid waste, causing secondary pollution. Summary of the invention

[0004] In order to overcome the shortcomings of the prior art, the present invention provides a high-concentration cutting fluid waste water reuse treatment system and its use method, which directly uses biological methods as pretreatment before membrane filtration, and the final effluent can be reused for preparing cutting fluid.

[0005] The technical solution adopted by the present invention to solve its technical problem is:

[0006] In the first aspect, the present application provides a water reuse treatment system for high-concentration cutting fluid waste liquid, which includes a coarse filter, a biological device, a water storage tank, a centrifuge, a silicon carbide membrane filter and a nanofiltration membrane filter in the order through which the liquid passes under working conditions. The biological device is an upflow biofilm reactor filled with fillers inside, and the fillers are loaded with microorganisms that have been trained to proliferate using cutting fluid waste liquid as a substrate. The coarse filter, the silicon carbide membrane filter and the nanofiltration membrane filter have decreasing particle diameters allowed to pass.

[0007] The high-concentration cutting fluid waste water reuse treatment system provided in the present application uses a coarse filter to simply intercept large solid impurities such as metal cutting and floating dust, and then directly uses biological treatment to replace the chemical treatment in the prior art as a pretreatment before membrane filtration. There is no secondary pollution. The biological treatment can degrade the difficult-to-treat substances in the high-concentration cutting fluid waste water to a great extent, which is beneficial to prolonging the available time of the membrane working at high throughput. In addition, the use of silicon carbide membrane and nanofiltration membrane for secondary filtration is beneficial to reducing the load of the filtration membranes at all levels and effectively alleviating the membrane pollution problem.

[0008] Furthermore, the diameter of particles allowed to pass through the silicon carbide membrane filter is 100nm~500nm. The silicon carbide membrane is used to continue to reduce the COD value of the effluent of the biological device, and can effectively filter out the medium-sized suspended matter and organic matter in the cutting fluid waste. If the diameter of particles allowed to pass through the silicon carbide membrane filter is too large, the burden on the nanofiltration membrane is heavy, and the effect of further reducing COD is not obvious. If the diameter of particles allowed to pass through the silicon carbide membrane is too small, the membrane flux of the silicon carbide membrane itself decreases rapidly. The silicon carbide membrane of the preferred size helps to remove suspended particles, improve processing efficiency, and reduce the pollution burden of two-stage membrane filtration.

[0009] Furthermore, the nanofiltration membrane filter allows the particle diameter to pass through to be 1nm~5nm. The ultra-high precision filtration capacity of the nanofiltration membrane enables it to remove tiny dissolved substances and organic pollutants in the waste cutting fluid, and can continue to reduce COD. In combination with the silicon carbide membrane of the preferred size, each has its own division of labor, which is conducive to the two-stage filtration membrane to maintain high-throughput operation for a long time, and jointly create a highly selective filtration effect, ensuring that the treated water meets the standards for the re-matching of cutting fluid, which is conducive to the efficient reuse of reclaimed water.

[0010] Furthermore, the biological device includes an outer cylinder and an inner cylinder, the cylinder wall of the outer cylinder is a heat-insulating material, the filler is filled in the inner cylinder, the outer cylinder and the inner cylinder are filled with a fluid heat-insulating medium, a stirring mechanism is provided at the top of the inner cylinder, a filler interception net is provided at the water outlet of the inner cylinder, and a water inlet of the inner cylinder is provided at the bottom of the inner cylinder.

[0011] The thermal insulation material of the outer cylinder ensures the temperature stability of the environment in which the internal microorganisms are located, which is conducive to promoting the proliferation and metabolic activities of microorganisms. The polyurethane sponge and fluidized bed K1 filler in the inner cylinder provide a large surface area, which is conducive to the attachment and growth of microorganisms. The liquid in the inner cylinder flows from bottom to top, which is conducive to full reaction with the microorganisms and creates an anaerobic environment, thereby giving full play to the degradation ability of microorganisms.

[0012] Furthermore, based on the volume of the inner tube, the filler includes 30% to 40% of polyurethane sponge and 20% to 30% of fluidized bed K1 filler.

[0013] The combination of polyurethane sponge and fluidized bed K1 filler optimizes the biofilm culture environment inside the biological device, which is beneficial to improving processing efficiency and enhancing the stability and durability of the system.

[0014] In a second aspect, the present application provides a method for using the water reuse treatment system for high-concentration cutting fluid waste liquid described in the first aspect, the steps comprising: pumping the cutting fluid waste liquid filtered by the coarse filter into the biological device, collecting the effluent from the biological device into the water storage tank, removing flocs from the water in the water storage tank by the centrifuge and pumping it into the silicon carbide membrane filter, injecting the effluent from the silicon carbide membrane filter into the nanofiltration membrane filter, and recovering the effluent from the nanofiltration membrane filter.

[0015] This method achieves multi-stage treatment of waste liquid. Large particles are removed through preliminary coarse filtration, reducing the burden of subsequent treatment. Biochemical treatment can efficiently degrade organic matter, replacing chemical methods that consume large amounts of drugs and produce large amounts of solid waste to reduce the COD value of waste liquid. The centrifuge removes flocs and effectively reduces pollution problems during the treatment process.

[0016] Furthermore, before operation, the start-up step of the biological device includes: inoculating the seed liquid of the microorganism and the stock solution of the waste cutting fluid into the biological device for the first time, stopping the water inlet and outlet of the biological device, culturing for 24h~48h, domesticating the microorganisms in the biological device in three stages, then emptying the biological device, inoculating the additional seed liquid of the microorganism and the stock solution of the waste cutting fluid into the biological device for the second time, and maintaining continuous water inlet and outlet;

[0017] In the three-stage domestication, the influent of the first stage is the culture solution simulating diluted wastewater, the influent of the second stage is the cutting fluid waste liquid stock solution treated by the silicon carbide membrane filter, and the influent of the third stage is the cutting fluid waste liquid stock solution.

[0018] Domesticating microorganisms in stages can gradually adjust the adaptability of microorganisms, so that they can effectively use the complex organic matter in the cutting fluid waste as a substrate, ensuring that the microorganisms have a strong degradation ability in the subsequent treatment process. The culture medium in the first stage provides sufficient nutrition to promote the rapid proliferation of microorganisms and initial adaptation to the environment. In the second stage, the silicon carbide membrane filter needs to be connected to the biological device. With the help of the silicon carbide membrane, a certain amount of COD can be removed, gradually allowing the microorganisms to adapt to using only cutting fluid waste as a carbon source. The third stage ensures that the microorganisms can continue to grow in the cutting fluid waste and degrade organic matter.

[0019] Furthermore, the three-stage domestication step includes:

[0020] The first stage: open the water inlet and outlet, set the hydraulic retention time to 96h~168h, stop the water inlet and outlet when the COD removal rate reaches 60% of the inlet water in this stage, and stir for 24h;

[0021] The second stage: open the water inlet and outlet, set the hydraulic retention time to 96h~168h, stop the water inlet and outlet when the COD removal rate reaches 50% of the inlet water in this stage, and stir for 24h;

[0022] The third stage: open the water inlet and outlet, set the hydraulic retention time to 120h~240h, stop the water inlet and outlet when the COD removal rate reaches 50% of the inlet water in this stage, stir for 24h, and then let it stand for 48h.

[0023] Controlling the hydraulic retention time and the end point of each stage helps ensure that the microbial acclimation process is orderly and stable, so that the microorganisms can efficiently degrade the cutting fluid waste liquid. The parameter design of each stage can ensure that the microorganisms can be fully cultivated and adapted at each stage, gradually improving the efficiency and effect of treating waste liquid, which is conducive to improving COD removal rate, optimizing the degradation ability of microorganisms, and reducing the burden of subsequent membrane filtration.

[0024] Furthermore, the culture medium includes 2 g / L ~5g / L NH4NO3, 2 g / L ~5g / L K2HPO4, 5 g / L ~10g / L KH2PO4, 10 g / L ~25g / L glucose, 30mL / L ~50mL / L liquid paraffin, 1 mL / L trace elements and 1 mL / L vitamins.

[0025] This culture medium formula provides rich nutritional support for microorganisms, ensuring their rapid growth and proliferation, especially when the microorganisms are first exposed to high-concentration cutting fluid waste, thereby improving the survival ability of the microorganisms.

[0026] Furthermore, during the first inoculation, the volume ratio of the seed liquid to the cutting fluid waste liquid stock solution is 2:3; during the second inoculation, the volume ratio of the seed liquid to the cutting fluid waste liquid stock solution is 1:1.

[0027] The proliferation rate and adaptability of microorganisms can be regulated by a reasonable inoculation ratio. The first inoculation of a higher proportion of waste liquid can speed up the adaptation process of microorganisms, so that the biofilm-forming microorganisms have the ability to efficiently degrade cutting fluid waste. The 1:1 ratio during the second inoculation can replenish the number of microorganisms, further improve the degradation efficiency of the biological device, and enable it to better treat high-concentration waste liquid. This inoculation ratio regulation ensures that the microorganisms can maintain a high activity and treatment capacity throughout the biochemical reaction process.

[0028] The beneficial effects of the present invention are as follows: the present invention directly replaces the chemical treatment in the prior art with biological treatment as the pretreatment before membrane filtration, does not consume a large amount of reagents, is beneficial to reducing secondary pollution when treating cutting fluid waste liquid, utilizes the advantage of high degree of decomposition of organic matter by microorganisms to conduct a relatively thorough treatment of the complex organic components in high-concentration cutting fluid waste liquid, reduces the COD of the cutting fluid waste liquid, greatly alleviates the pollution problem of subsequent membrane treatment, maintains high-throughput operation of the membrane, and extends the life of the membrane. The treated effluent can be reused in the preparation of cutting fluid working fluid, thereby realizing the reduction and resource utilization of cutting fluid waste liquid.

[0029] Other features and advantages of the present application will be described in the following description, and partly become apparent from the description, or understood by practicing the present application. The purpose and other advantages of the present application can be realized and obtained by the structures particularly pointed out in the written description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 It is a connection relationship diagram of a water reuse treatment system for high-concentration cutting fluid waste provided in an embodiment of the present application.

[0031] Figure 2 It is a schematic diagram of the operation process of a water reuse treatment system for high-concentration cutting fluid waste provided in an embodiment of the present application.

[0032] Figure 3 This is a comparison chart of water inlet patterns when acclimating microorganisms in a biological device in three stages. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solution and advantages of the embodiments of the present disclosure clearer, the technical solution of the embodiments of the present disclosure is clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present disclosure, not all of the embodiments. Based on the described embodiments of the present disclosure, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] It should be understood that, under the premise of no conflict, any and all embodiments of the present invention can be combined with the technical features in any other embodiment or multiple other embodiments to obtain another embodiment. The present invention includes such a combination to obtain another embodiment.

[0035] Unless otherwise specified, all technical and scientific terms used herein have the standard meaning in the field to which the claimed subject matter belongs. If there are multiple definitions for a term, the definition herein shall prevail.

[0036] The existing process for treating waste cutting fluid in the prior art is chemical method (pretreatment) - physical method (membrane filtration) - biological method (deep treatment). The purpose of the present invention is to make the treated water available for preparing cutting fluid working fluid (it is not required to meet the sewage discharge standard, and if necessary, it can continue to be deeply treated), and to reduce drug consumption and secondary pollution.

[0037] Reference Figure 1 The embodiment of the present application provides a water reuse treatment system for high-concentration cutting fluid waste liquid, which includes a coarse filter, a biological device, a water storage tank, a centrifuge, a silicon carbide membrane filter and a nanofiltration membrane filter in the order in which the liquid passes under working conditions. The biological device is an upflow biofilm reactor filled with fillers inside, and the fillers are loaded with microorganisms that have been domesticated to proliferate using cutting fluid waste liquid as a substrate. The coarse filter, the silicon carbide membrane filter and the nanofiltration membrane filter allow the particles to pass through in decreasing diameters.

[0038] Microorganisms have unique advantages in degrading organic matter. Microorganisms that can use high-concentration complex organic matter as substrates (commercially available strains can be used, and the present invention mainly studies how to arrange the treatment system) can greatly decompose and oxidize substances that are difficult to treat in high-concentration cutting fluid waste, which can not only save a lot of cost of using chemical agents, but also reduce secondary pollution. Using microbial treatment as pretreatment and subsequent coupling membrane filtration can effectively alleviate the problem of membrane pollution. The microorganism can be a commercially available composite bacterial agent; or a variety of existing single-strain bacterial agents can be selected for use in combination. For example, in some embodiments, the inoculated microorganisms are 15% to 50% of Pseudomonas putida (the percentage refers to first culturing various bacterial agents into seed liquid and then mixing them by volume), 15% to 50% of Pseudomonas aeruginosa, 10% to 50% of Bacillus brevis, and 10% to 50% of Bacillus subtilis.

[0039] The method for using the water reuse treatment system for high-concentration cutting fluid waste provided in the embodiment of the present application includes the following steps: pumping the cutting fluid waste filtered by a coarse filter into a biological device, collecting the effluent from the biological device into a water storage tank, removing flocs from the water in the water storage tank by a centrifuge and then pumping it into a silicon carbide membrane filter, injecting the effluent from the silicon carbide membrane filter into a nanofiltration membrane filter, and recovering the effluent from the nanofiltration membrane filter.

[0040] For example, refer to Figure 2 The machining equipment generates cutting fluid waste, which is temporarily stored in a cutting fluid waste pool. The cutting fluid waste pool is connected to the high-concentration cutting fluid waste water reuse treatment system of the embodiment of the present application. First, the coarse filter intercepts large solid impurities such as metal cutting and floating dust, and then pumps them into the biological device from the bottom. The effluent of the biological device flows to the water storage tank for buffering, and the water storage tank can play a certain role in static sedimentation. Then the water in the water storage tank is pumped to the centrifuge to separate the flocs, and the upper liquid continues to be pumped to the two-stage membrane filtration equipment.

[0041] The biological device may include an outer tube and an inner tube, the outer tube wall is made of heat-insulating material, fillers are filled in the inner tube, a fluid heat-insulating medium is filled between the outer tube and the inner tube, a stirring mechanism is arranged on the top of the inner tube, a filler interception net is arranged at the water outlet of the inner tube, and a water inlet of the inner tube is arranged at the bottom of the inner tube. The fluid heat-insulating medium may be warm water, so that the inner tube is kept warm at 35±1°C.

[0042] The coarse filter may be a filter screen arranged at the water inlet of the inner cylinder.

[0043] The flocs separated by the centrifuge are actually microbial flocs, which belong to activated sludge and have the functions of adsorption, coagulation and sedimentation, and can be used for water treatment elsewhere.

[0044] The two-stage membrane filtration equipment can specifically be a silicon carbide membrane filter that allows particles with a diameter of 100nm to 500nm to pass through and a nanofiltration membrane filter that allows particles with a diameter of 1nm to 5nm to pass through. The nanofiltration membrane is an organic membrane. The silicon carbide membrane filter discharges the discarded primary concentrate, and the nanofiltration membrane filter discharges the discarded secondary concentrate. The primary concentrate and the secondary concentrate can be outsourced for harmless treatment. Compared with the pretreatment using chemical methods, the primary concentrate and the secondary concentrate formed by the biological method as pretreatment are less, and no secondary polluted solid waste will be generated.

[0045] Implementation Cases

[0046] The water quality indicators of the cutting fluid waste liquid of a precision mold processing plant production line are shown in Table 1. The COD of the liquid is 120,000 mg / L~170,000 mg / L.

[0047] Table 1

[0048] project Properties and related physical and chemical properties Detection Methods Appearance Milky white emulsion, containing oily and solid impurities Visual inspection odor Rancid Smell Emulsion concentration 9 Handheld Refractometer pH 8.59 pH Meter Conductivity (µs / cm ) 8702 Conductivity meter COD (mg / L) 145762 Water quality analyzer bacteria <![CDATA[10 7 ]]> Bacteria test piece Fungi 0 Bacteria test piece

[0049] Commercially available wastewater treatment microecological preparations (Polycore Bio) were selected and activated into seed solution.

[0050] 8 L of seed liquid and 12 L of cutting fluid waste liquid were inoculated into the biodevice, which was filled with 30%~40% polyurethane sponge and 20%~30% fluidized bed K1 filler. After inoculation, the stirring paddle inside the biodevice was started to stir slowly for 24h~48h, and then water was continuously added.

[0051] The biological device used is a double-layer cylindrical device with a working volume of 20 L (the working volume is not the maximum limit volume, and the polyurethane sponge and fluidized bed K1 filler are both porous and loose materials, and the above-mentioned seed liquid and cutting fluid waste liquid can still be poured in after the filler is placed), the inner layer is the reaction layer, the outer layer material is the insulation layer, the middle part of the inner and outer layers is filled with tap water, and the tap water is heated to keep the inner layer warm at 35±1℃, a stirring paddle is installed on the top of the device, and a filter is installed on the inner wall of the outlet to intercept the filler.

[0052] Reference Figure 3 In the middle part a, the first stage of water inflow is a compound culture solution, and the HRT is set to 96h~168h. At this time, the effluent of the biological device is first measured at the COD detection place (such as laboratory, online COD detection instrument), and then can be received in an additional container for later treatment. After the COD removal rate reaches 60% (60% of the COD of the culture solution), the water inflow is stopped and stirred for 24 hours. The culture solution formula is: 2 g / L NH4NO3, 2 g / L K2HPO4, 5 g / L KH2PO4, 25g / L glucose, 50mL / L liquid paraffin, 1 mL / L trace elements, 1 mL / L vitamins. The purpose of this stage is to rapidly and massively proliferate microorganisms, and at the same time, to selectively screen and enrich microorganisms with demulsification ability.

[0053] Reference Figure 3 In the middle part b, the second stage influent is the effluent after the cutting fluid waste liquid enters the silicon carbide membrane filter for treatment. The HRT is set to 96h~168h. When the COD removal rate reaches 50% (50% of the cutting fluid waste liquid treated by the silicon carbide membrane filter), the water inlet is stopped and stirred for 24 hours. The cutting fluid waste liquid passes through the coarse filter to remove large solid particles such as metal chips and floating dust, and then is pumped into the silicon carbide membrane filter by the sewage lift pump, and then the filtered water is pumped into the water inlet at the bottom of the biological device. At this stage, the silicon carbide membrane intercepts some macromolecular substances, and the substances in the effluent are relatively easier to be used by microorganisms, thereby promoting the proliferation and functionalization of microorganisms.

[0054] Reference Figure 3 In the middle part c, the third stage water inlet is the original cutting fluid waste liquid, and the HRT is set to 120h~240h. When the COD removal rate reaches 50% (50% of the original cutting fluid waste liquid), the water inlet is stopped, and the mixture is stirred for 24h and then allowed to stand for 48h.

[0055] Empty the liquid in the inner cylinder, inoculate 10 L of seed liquid and 10 L of cutting fluid waste liquid again, continue to add water and stir, then press Figure 1 The whole high-concentration cutting fluid wastewater recycling treatment system is set up in the form of connection, and it works normally and continuously. The inlet water is the original cutting fluid wastewater, and the HRT is set to 120~240 h. After the effluent COD is stable, the HRT is gradually shortened. Finally, the COD removal rate of the biological device effluent reaches about 63%.

[0056] The waste liquid after biochemical treatment was collected in a water storage tank, and the liquid in the water storage tank was added to the centrifuge. The speed was adjusted to 4000 r / min, and centrifuged for 15 min to remove part of the microbial flocs to obtain the microbial pretreatment liquid.

[0057] The microbial pretreatment liquid was injected into a 100 nm ~ 500 nm silicon carbide membrane filter to obtain SiC effluent. The relevant properties of the SiC effluent were tested, and the results are shown in Table 2.

[0058] The SiC effluent was injected into a 1 nm ~ 5 nm nanofiltration membrane filter to obtain NF effluent. The relevant properties of the NF effluent were tested and the results are shown in Table 2.

[0059] Table 2

[0060]

[0061] Among them, "stock solution-biochemical" means the effluent of the biological device, "stock solution-biochemical-SiC" means the effluent of the silicon carbide membrane filter, and "stock solution-biochemical-SiC-NF" means the effluent of the nanofiltration membrane filter. The results show that the high-concentration cutting fluid waste liquid can be directly pre-treated by biological methods. After being treated by the high-concentration cutting fluid waste liquid water reuse treatment system of the embodiment of the present application, the COD value is greatly reduced, and the effluent is sterile, transparent, and odorless. Although the COD value still exceeds the discharge standard, it has met the requirements for reuse in the preparation of cutting fluid working fluid.

[0062] Application Example 1

[0063] The water effluent from the silicon carbide membrane filter after the system in the above implementation case works normally is taken as dilution water to prepare the cutting fluid working fluid. By volume, the cutting fluid concentrate accounts for 5%, and the water effluent from the silicon carbide membrane filter accounts for 95%, which is recorded as "95% SiC+5% cutting fluid".

[0064] Application Example 2

[0065] The effluent from the nanofiltration membrane filter after the system in the above implementation case works normally is taken as dilution water to prepare the cutting fluid working fluid. By volume, the cutting fluid concentrate accounts for 5% and the effluent from the nanofiltration membrane filter accounts for 95%, which is recorded as "95% NF+5% cutting fluid".

[0066] Comparison Example

[0067] Use deionized water as dilution water to prepare the cutting fluid working fluid. By volume, the cutting fluid concentrate accounts for 5% and deionized water accounts for 95%, which is recorded as "95% deionized water + 5% cutting fluid".

[0068] The physical and chemical properties of Application Example 1, Application Example 2 and Control Example were tested, and the results are shown in Table 3.

[0069] Table 3

[0070] sample 95% SiC+5% cutting fluid 95% NF +5% cutting fluid 95% deionized water + 5% cutting fluid Appearance Light yellow microemulsion White microemulsion White microemulsion odor No odor No odor No odor pH 9.40 9.63 9.72 Conductivity (µs / cm ) 6754 2208 1089 bacteria 0 0 0 Fungi 0 0 0

[0071] The working performance of Application Example 1 and Application Example 2 was tested, and the results are shown in Table 4.

[0072] Table 4

[0073] sample 95% SiC+5% cutting fluid 95% NF +5% cutting fluid Cast iron corrosion inhibition Grade D / Unsatisfactory A-level / pass 7075 aluminum corrosion inhibition A-level / pass A-level / pass Copper corrosion inhibition A-level / pass A-level / pass

[0074] It can be seen from Table 4 that when the cutting fluid is prepared with SiC water, the corrosion inhibition of cast iron is D level, which is unqualified, and the others are all A level; when the cutting fluid is prepared with NF water, the corrosion inhibition of cast iron, 7075 aluminum and copper are all A level.

[0075] For 7075 aluminum alloy, the lubricity of the cutting fluid prepared with SiC effluent and NF effluent as dilution water is not much different, and is similar to that of deionized water.

[0076] In the description of this specification, the description with reference to the terms "one embodiment", "certain embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0077] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the scope of protection of the present invention.

Claims

1. The method for using the water recycling treatment system for high-concentration cutting fluid waste is characterized by: The system comprises a coarse filter, a biological device, a water storage tank, a centrifuge, a silicon carbide membrane filter and a nanofiltration membrane filter in the order in which the liquid passes under working conditions. The biological device is an upflow biofilm reactor filled with fillers, and the fillers are loaded with microorganisms that have been domesticated to grow with cutting fluid waste as a substrate. The coarse filter, the silicon carbide membrane filter and the nanofiltration membrane filter have decreasing particle diameters allowed to pass through. The silicon carbide membrane filter allows particles with a diameter of 100nm to 500nm to pass through; The nanofiltration membrane filter allows the particle diameter to pass through to be 1nm~5nm; The biological device comprises an outer cylinder and an inner cylinder, the cylinder wall of the outer cylinder is a heat-insulating material, the filler is filled in the inner cylinder, a fluid heat-insulating medium is filled between the outer cylinder and the inner cylinder, a stirring mechanism is arranged on the top of the inner cylinder, a filler interception net is arranged at the water outlet of the inner cylinder, and a water inlet of the inner cylinder is arranged at the bottom of the inner cylinder; According to the volume of the inner cylinder, the filler includes 30% to 40% of polyurethane sponge and 20% to 30% of fluidized bed K1 filler; The method of use comprises the following steps: pumping the waste cutting fluid filtered by the coarse filter into the biological device, collecting the effluent of the biological device into the water storage tank, removing flocs from the water in the water storage tank by the centrifuge and then pumping it into the silicon carbide membrane filter, injecting the effluent of the silicon carbide membrane filter into the nanofiltration membrane filter, and recovering the effluent of the nanofiltration membrane filter; Before operation, the start-up steps of the biological device include: inoculating the seed liquid of the microorganism and the stock solution of the waste cutting fluid into the biological device for the first time, stopping the water inlet and outlet of the biological device, culturing for 24h~48h, domesticating the microorganisms in the biological device in three stages, then emptying the biological device, inoculating the additional seed liquid of the microorganism and the stock solution of the waste cutting fluid into the biological device for the second time, and maintaining continuous water inlet and outlet; In the three-stage domestication, the influent of the first stage is the culture solution simulating diluted wastewater, the influent of the second stage is the cutting fluid waste liquid stock solution treated by the silicon carbide membrane filter, and the influent of the third stage is the cutting fluid waste liquid stock solution.

2. The method for using the water recycling treatment system for high-concentration cutting fluid waste according to claim 1 is characterized in that: The three-stage domestication process includes: Stage 1: Open the water inlet and outlet, set the hydraulic retention time to 96h~168h, stop the water inlet and outlet when the COD removal rate reaches 60% of the inlet water at this stage, and stir for 24h; The second stage: open the water inlet and outlet, set the hydraulic retention time to 96h~168h, stop the water inlet and outlet when the COD removal rate reaches 50% of the inlet water in this stage, and stir for 24h; The third stage: open the water inlet and outlet, set the hydraulic retention time to 120h~240h, stop the water inlet and outlet when the COD removal rate reaches 50% of the inlet water in this stage, stir for 24h, and then let it stand for 48h.

3. The method for using the high-concentration cutting fluid waste water reuse treatment system according to claim 1, characterized in that: The culture medium includes 2 g / L ~5g / L NH4NO3, 2 g / L ~5g / L K2HPO4, 5 g / L ~10g / L KH2PO4, 10g / L ~25g / L glucose, 30mL / L ~50mL / L liquid paraffin, 1 mL / L trace elements and 1 mL / L vitamins.

4. The method for using the high-concentration cutting fluid waste water recycling treatment system according to claim 1, characterized in that: During the first inoculation, the volume ratio of the seed liquid to the original cutting fluid waste liquid is 2:3; during the second inoculation, the volume ratio of the seed liquid to the original cutting fluid waste liquid is 1:1.

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