Sewage zero-discharge treatment device for filter production line

Abstract

The utility model discloses a sewage zero-discharge treatment device for a filter production line, and belongs to the field of wastewater treatment. The device comprises an oil removal unit, a reaction unit, a filtering unit, a water production unit, a chemical adding unit, a sludge treatment unit and a concentrated water treatment unit, the feeding unit, the reaction unit, the filtering unit and the water production unit are connected in sequence, and the chemical adding unit is connected with the reaction unit and the filtering unit. The sludge treatment unit is respectively connected with the reaction unit and the filtering unit, the concentrated water treatment unit is connected with the rear end of the filtering unit, the device is used for treating the sewage of the filter production line, the operation is simple, the daily operation is stable, and the effluent quality can meet the water quality of industrial water for recycling urban sewage.

Description

Technical Field

[0001] The utility model belongs to the field of wastewater treatment, and more specifically relates to a zero-discharge treatment device for wastewater of a filter production line. Background Art

[0002] The comprehensive wastewater generated during the production of filters belongs to mechanical processing oily wastewater, and the main pollutants are CODcr and SS, etc. The chemical oxygen demand (COD) concentration of the influent is 80-151 mg / L, the biological oxygen demand (BOD) concentration is 30-40 mg / L, the ammonia nitrogen (NH3-N) concentration is 0.043-1.10 mg / L, the total phosphorus (TP) concentration is 0.18-0.29 mg / L, the iron (Fe) concentration is 0.21-1.11 mg / L, the zinc (Zn) concentration is 0.05-0.24 mg / L, the nickel (Ni) concentration is <0.05 mg / L, the pH is between 8.80-10.16, which is alkaline, and the suspended solids (SS) concentration is 34-51 mg / L.

[0003] The existing treatment technology for zero-discharge of wastewater from filter production lines is generally "grease trap + flocculation sedimentation tank + biochemical tank + secondary sedimentation tank". The oil in the wastewater needs to be removed, and the dosage of the flocculation sedimentation tank is large, and the operating cost is high. At the same time, the wastewater discharged locally complies with the process and product water standards in "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB / T 19923-2005).

[0004] After searching, CN113603302A discloses a treatment method for reducing the amount of coking wastewater. After the coking wastewater is treated by regulating tank, flotation oil removal, coagulation sedimentation, biochemical homogenization tank, biological filter, secondary sedimentation tank, UV advanced ozone oxidation, ultrafiltration, reverse osmosis, chemical softening tank, sand filtration, resin, regulating tank, ultrafiltration, nanofiltration, bipolar membrane electrodialysis process, the acid and alkali produced can be used for pH adjustment and other process reuse in the treatment process. This patent is aimed at coking wastewater, whose components mainly include pollutants such as ammonia and phenol. It is not suitable for filter production line wastewater containing heavy metals and mineral oil.

[0005] Patent CN114906975A discloses a zero-discharge treatment process for coking wastewater, including biochemical treatment, deep treatment and salt separation crystallization, wherein the deep treatment includes wastewater pretreatment, reverse osmosis concentration and sludge dehydration. Wastewater pretreatment includes pretreatment dosing, high-efficiency clarification, multi-media filtration, ultrafiltration, resin softening, carbon dioxide removal and organic matter removal, and organic matter removal includes adsorption in the adsorption tank, desorption outside the adsorption tank and wet oxidation of elution waste liquid.

[0006] Patent CN107253798A relates to a combined process for deep treatment and reuse of wastewater from the steel industry. After being treated by a cooling unit and an immersion ultrafiltration unit, the wastewater from the steel industry first enters a reverse osmosis unit for primary desalination. The reverse osmosis water produced after desalination is sent to the water supply system for graded reuse. The concentrated water produced by the reverse osmosis unit is successively treated by a softening clarification tank, an ozone oxidation tank, a nitrification and denitrification biofilter, a multi-media filter, an external pressure ultrafiltration unit, etc., and then enters a nanofiltration unit for secondary desalination. The nanofiltration water produced after desalination is sent to the water supply system for graded reuse. The concentrated water produced by the nanofiltration unit is then successively treated by Fenton oxidation, an ozone oxidation tank, an activated carbon biofilter, and a breakpoint chlorination tank before being discharged in compliance with the standards. However, there is no oil in the steel wastewater, so there is no need to consider the impact of oil on wastewater treatment.

[0007] Patent CN101935118A discloses a hot water membrane purification and reuse process, which is a combination of ultrafiltration, microfiltration membrane system, reverse osmosis, nanofiltration membrane system, pretreatment, activated carbon adsorption and ion exchange. It can work at high temperature and can purify a variety of hot water and wastewater. It has the dual function of recovering water resources and thermal energy. Different process combinations and processes can be adopted according to the composition of water quality. The difference between it and the present application is the removal of oil such as mineral oil. Utility Model Content

[0008] 1. Problem to be solved

[0009] Aiming at the problem that existing devices are difficult to treat filter production line wastewater with poor biodegradability, high suspended matter concentration and high hardness, the utility model provides a filter production line wastewater zero-discharge treatment device. The device is used to treat filter production line wastewater, and the operation is simple, the daily operation is stable, and the effluent water quality can meet the "Water Quality for Industrial Water Use in Urban Wastewater Recycling".

[0010] 2. Technical solution

[0011] In order to solve the above problems, the technical solution adopted by the utility model is as follows:

[0012] A zero-discharge treatment device for wastewater of a filter production line comprises an oil removal unit, a reaction unit, a filtration unit, a water production unit, a dosing unit, a sludge treatment unit and a concentrated water treatment unit, wherein the oil removal unit, the reaction unit, the filtration unit and the water production unit are connected in sequence, the dosing unit is respectively connected to the reaction unit and the filtration unit, the sludge treatment unit is respectively connected to the reaction unit and the filtration unit, and the concentrated water treatment unit is connected to the rear end of the filtration unit.

[0013] The oil removal unit comprises an oil separation regulating tank, which is equipped with a lifting pump for inputting sewage into the reaction unit.

[0014] Furthermore, the oil-water separator and regulating tank is a multi-compartment oil-water separator and regulating tank with a rectangular plane, which is provided with a plurality of tank bodies, and the side wall of the oil-water separator and regulating tank is provided with water holes, and sewage flows between adjacent oil-water separator and regulating tanks through the water holes.

[0015] The reaction unit comprises an air flotation tank, a softening and coagulation tank and an ozone catalytic oxidation tank which are connected in sequence.

[0016] The flotation tank includes a tank body and a gas dissolving device, the gas dissolving device includes a gas dissolving tank and a gas flotation gas dissolving pump connected to the gas dissolving tank, the gas dissolving tank passes gas into the tank body below the liquid surface through the gas flotation gas dissolving pump. The flotation tank is also provided with a scraping device, the scraping device includes at least one scraping plate, the scraping plate is located above the liquid surface of the flotation tank, and is operated by a driving device. A sludge tank is provided below the flotation tank, and the impurities continuously floating on the surface are scraped into the sludge tank through the continuous operation of the scraping plate. The treated sewage overflows from the pipeline to the softening and coagulation tank.

[0017] The softening coagulation tank includes a reaction tank and a sedimentation tank, which are separated by a baffle plate, and a water hole is provided on the baffle plate, through which wastewater flows between the reaction tank and the sedimentation tank, and the sedimentation tank is used to gravity settle the flocculent precipitate generated in the reaction tank, and is connected to the sludge tank through a pipeline below. A stirring device is provided in the reaction tank to mix the wastewater and the reaction reagent evenly.

[0018] Furthermore, the sedimentation tank is provided with mutually parallel inclined pipes, and the inclined pipes are preferably made of PP material. The wastewater and reaction reagents in the sedimentation tank are partitioned by the inclined pipes to reduce precipitation accumulation and enrichment, which affects the sedimentation efficiency.

[0019] The ozone catalytic oxidation tank is isolated from the sedimentation tank by a baffle, an overflow weir is arranged on the upper part of the baffle, an ozone generator is arranged in the ozone catalytic oxidation tank for oxidative removal of organic matter, and finally the treated sewage enters the filtering unit for filtration.

[0020] Furthermore, it also includes an internal circulation pump, through which circulation is performed to allow ozone and sewage to fully react.

[0021] The filtration unit includes a multi-media filter and a SNF membrane device connected in sequence.

[0022] The SNF membrane device includes a precision filter and an SNF membrane assembly, which is used to remove pollutants such as COD, ammonia nitrogen, and divalent salts in wastewater. The water produced by the SNF membrane system can be reused up to the standard after entering the water production tank. Among them, a SNF booster pump is provided in front of the precision filter to boost the water entering the precision filter, and a SNF high-pressure pump is provided in front of the SNF membrane assembly to boost the water entering the SNF membrane assembly.

[0023] Furthermore, a raw water tank is provided between the multi-media multi-filter and the SNF membrane device.

[0024] The SNF membrane device is connected to the production water tank, and the produced water that meets the reuse water standard is reused in the production process through the reuse water pump.

[0025] The dosing unit comprises at least one dosing tank for adding materials to the flotation tank and the softening and coagulation tank. A valve is arranged on the dosing pipeline of the dosing tank for controlling the dosing flow rate.

[0026] The sludge treatment unit includes a plate and frame filter press, which is connected to the sludge tank and is used to receive the sludge scraped from the flotation tank scraper and the sludge settled to the bottom of the sedimentation tank. The plate and frame filter press filters the sludge and the filtered sludge is outsourced for treatment.

[0027] Furthermore, during the plate and frame filtration process, the air compressor drives the pneumatic diaphragm pump to achieve rapid sludge filtration.

[0028] The concentrated water treatment unit includes a concentrated water bucket, which is connected to the SNF membrane assembly and receives concentrated water processed by the SNF membrane assembly. One end of the concentrated water bucket is connected to the flotation tank, and part of the concentrated water in the concentrated water bucket is passed into the flotation tank and then processed through the reaction unit and the filtration unit. The other end of the concentrated water bucket is connected to a concentrated water circulation bucket, which is sequentially connected to a low-temperature evaporation concentrator and a cooling tower. The concentrated water is cooled by the low-temperature evaporation concentrator, and salt is precipitated at a low temperature. The temperature is controlled at about 160-200°C.

[0029] Wherein, the flotation tank and the reaction tank are provided with stirring devices for uniformly mixing the reactants.

[0030] The flotation tank is provided with an online pH meter to control the pH of the wastewater in the reaction unit to be between 7 and 8.

[0031] A method for zero-discharge treatment of wastewater using the filter production line comprises the following steps:

[0032] S1. Oil separation treatment: Wastewater flows into the oil separation regulating tank for oil separation treatment.

[0033] Among them, oil separation treatment uses the different specific gravity of suspended matter and water in wastewater to achieve the purpose of separation. When the oily wastewater enters the oil separation regulating tank, it flows slowly in the horizontal direction, passing through multiple oil separation regulating tanks, and the oil floats to the water surface during the flow. The water holes are set below the water surface to intercept the oil and other impurities floating on the water surface. The separated sewage enters the last grid through the water hole, and is then lifted to the flotation tank by the oil separation regulating tank lifting pump.

[0034] S2. Coagulation and flotation: The effluent from the oil separator and regulating tank is pumped to the flotation tank, and neutralizer, flocculant and coagulant aid are added. Under the action of dissolved air and water, pollutants such as oil, suspended solids, COD, etc. in the wastewater float to the water surface and are removed by the scraping system.

[0035] Among them, the neutralizer includes one or more of caustic soda, lime, and sodium carbonate, and its function is to adjust the wastewater to a suitable pH range, preferably 7-8, which is easy to coagulate; the flocculant includes one or more of PAC, aluminum sulfate, and ferrous chloride, and its function is to aggregate suspended matter and colloidal substances in the water; the coagulant aid includes one or more of PAM, PCE, and bio-colloid.

[0036] S3. Softening and coagulation: The clarified water from the flotation tank flows into the softening and coagulation tank. Under the action of softeners, flocculants and coagulants, the pollutants such as COD, suspended solids and heavy metals in the wastewater are further precipitated and removed to reduce the hardness of the water, reduce the metal ions in the concentrate after the membrane filtration, and reduce the amount of the concentrate.

[0037] Among them, the softener includes one or more of sodium carbonate, quicklime, and slaked lime, which are used to remove the hardness in the water, namely divalent metal ions such as calcium and magnesium; the flocculant includes one or more of PAC, aluminum sulfate, and ferrous chloride, which aggregates the precipitated substances formed by divalent metal ions; the coagulant aid includes one or more of PAM, PCE, and bio-glue, which connects the aggregated substances to increase the flocculent volume and facilitate precipitation.

[0038] The softening coagulation sedimentation tank hydraulics meet the 0.5m 3 / (m 2 h).

[0039] S4. Ozone oxidation: The supernatant water obtained from the sedimentation tank flows into the ozone catalytic oxidation tank, and the ozone generated by the ozone generator is used to strongly oxidize and remove the difficult-to-degrade substances in the wastewater.

[0040] Among them, an ozone generator is arranged in the ozone catalytic oxidation tank.

[0041] S5. Adsorption and filtration: The effluent from the ozone catalytic oxidation tank is pumped to the multi-media filter through the water inlet pump for adsorption and filtration of tiny suspended solids to ensure the stable operation of the subsequent treatment system.

[0042] The media in the multi-media filter include quartz sand, anthracite, activated carbon, magnetite, garnet, porous ceramics, plastic balls, etc. During the screening process of the multi-media filter, when water flows through the filter layer, larger particles and suspended matter will be intercepted in the depth of the filter material, while smaller particles and dissolved matter can pass through the filter layer. During the adsorption process, the fine pores of the adsorbent filter materials such as activated carbon can adsorb harmful substances such as organic matter, chlorine, odor, etc. in the water, so that the water quality is better purified.

[0043] S6. Nanofiltration: The effluent from the multi-media filter enters the SNF membrane system to remove pollutants such as COD, ammonia nitrogen, and divalent salts in the wastewater. The water produced by the SNF membrane system enters the water production tank and can be reused up to the standard. The removal rates of COD, ammonia nitrogen, and total phosphorus in the SNF membrane system are 60%-70%, 55%-60%, and 98%-99% respectively.

[0044] The utility model discloses a zero-discharge treatment method for wastewater from a filter production line, which utilizes the oxidizing property of ozone (oxidation potential 2.03V) to directly oxidize organic matter in water, or to oxidize and decompose macromolecular organic matter into small molecules, making them easier to degrade. Ozone catalytic oxidation technology is particularly suitable for treating wastewater with poor biodegradability. Ozone oxidation technology has a simple process, a short treatment time, and does not produce residues, and generally does not produce secondary pollution.

[0045] The present application adopts oil separation treatment → coagulation flotation → softening coagulation → ozone oxidation → filtration and adsorption → nanofiltration. It is worth noting that the method of the present application is particularly suitable for oily wastewater containing zinc, iron and nickel. The present application first adopts oil separation treatment to remove oil droplets with a particle size greater than 100um in the wastewater; uses coagulation flotation to remove finely dispersed oil with a particle size of 10 to 100um in the wastewater; then uses ozone oxidation to remove residual COD in the wastewater; and then uses filtration and adsorption to remove suspended matter in the wastewater and adsorb COD in the wastewater, providing protection for the subsequent nanofiltration system, reducing pollutants in the wastewater, and ensuring that the effluent meets the design requirements.

[0046] The treated effluent meets the process and product water standards in "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB / T 19923-2005).

[0047] 3. Beneficial effects

[0048] Compared with the prior art, the beneficial effects of the utility model are:

[0049] (1) The utility model provides a filter production line wastewater zero discharge treatment device which is provided with a feed unit, a reaction unit, a filtration unit and a water production unit connected in sequence, which is simple to operate and stable in daily operation, and the effluent water quality can meet the "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB / T 19923-2005);

[0050] (2) The utility model is provided with a concentrated water treatment unit, and the concentrated water obtained by the SNF membrane module is cooled and treated by a low-temperature evaporation concentrator. The effluent can be reused in the factory, meet the reuse water standard, and achieve zero discharge;

[0051] (3) The utility model is provided with a sludge treatment unit, which filters the sludge produced in the coagulation flotation and softening coagulation through a plate and frame filter press, and outsources the filtered sludge for post-processing of pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0052] The technical solution of the utility model will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for the purpose of explanation and are not intended to limit the scope of the utility model. In addition, unless otherwise specified, these drawings are only intended to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0053] Figure 1 This is a flow chart of zero-discharge treatment of wastewater in a filter production line of the utility model;

[0054] Figure 2 This is a schematic diagram of the oil removal unit structure of the utility model;

[0055] Figure 3 It is a schematic diagram of the reaction unit structure of the utility model;

[0056] Figure 4 This is a schematic diagram of the structure of the filter unit of the utility model;

[0057] Figure 5 This is a schematic diagram of the water production unit structure of the utility model;

[0058] Figure 6 This is a schematic diagram of the structure of the sludge treatment unit of the utility model;

[0059] Figure 7 This is a schematic diagram of the structure of the concentrated water treatment unit of the utility model;

[0060] 100. Oil removal unit: 110. Oil separation regulating tank;

[0061] 200, reaction unit: 210, flotation tank; 211, tank body; 212, air dissolving device; 2121, air dissolving tank; 2122, flotation air dissolving pump; 213, scraping device; 214, first stirring device; 215, sludge tank;

[0062] 220, softening and coagulation tank; 221, reaction tank; 2211, second stirring device; 222, sedimentation tank; 230, ozone catalytic oxidation tank; 231, ozone generator; 232, internal circulation pump;

[0063] 300, filtration unit: 310, multi-media filter; 320, raw water barrel; 330, SNF membrane device; 331, SNF booster pump; 332, precision filter; 333, SNF high-pressure pump; 334, SNF membrane assembly;

[0064] 400, water production unit: 410, water production tank; 411, recycling water pump;

[0065] 500, dosing unit: 510, first dosing tank; 520, second dosing tank; 530, third dosing tank; 540, fourth dosing tank; 550, fifth dosing tank;

[0066] 600. Sludge treatment unit: 610. Plate and frame filter press; 611. Air compressor; 612. Pneumatic diaphragm pump;

[0067] 700. Concentrated water treatment unit: 710. Concentrated water barrel; 720. Concentrated water circulation barrel; 730. Low-temperature evaporation concentrator; 740. Cooling tower. DETAILED DESCRIPTION

[0068] The following detailed description of exemplary embodiments of the utility model refers to the accompanying drawings, which form a part of the description, and in which exemplary embodiments that can be implemented by the utility model are shown as examples. Although these exemplary embodiments are described in sufficient detail to enable those skilled in the art to implement the utility model, it should be understood that other embodiments can be implemented and various changes can be made to the utility model without departing from the spirit and scope of the utility model. The following more detailed description of the embodiments of the utility model is not intended to limit the scope of the claimed utility model, but is only for illustration and does not limit the description of the characteristics and features of the utility model, so as to propose the best way to perform the utility model, and is sufficient to enable those skilled in the art to implement the utility model. Therefore, the scope of the utility model is limited only by the appended claims.

[0069] The devices in the embodiments of the present invention are all products available on the market.

[0070] In the prior art, biochemical treatment is generally used for sewage treatment, but biochemical treatment relies on the action of microorganisms, which are greatly affected by the seasons, have high requirements for the environment, and are unstable in operation. The sewage from the filter production line targeted by this application has a high concentration of heavy metals (iron, zinc, nickel), which toxicize microorganisms and affect the sewage treatment effect. In addition, microorganisms cannot regenerate, and the post-treatment process is complicated.

[0071] The present application adopts the process of oil separation treatment → coagulation flotation → softening coagulation → ozone oxidation → filtration and adsorption → nanofiltration for the treatment of wastewater from the filter production line. Compared with the existing technology, it adopts a non-biochemical treatment method.

[0072] The wastewater of the filter production line contains oil, suspended solids 34-51 mg / L, ammonia nitrogen 0.043-1.10 mg / L, total phosphorus 0.18-0.29 mg / L, iron ion 0.21-1.11 mg / L, zinc ion 0.05-0.24 mg / L, nickel ion <0.05 mg / L, COD 80-151 mg / L, and five-day biochemical oxygen demand 35.1 mg / L. First, oil separation treatment is used to remove oil droplets with a particle size greater than 100 nm in the wastewater to prevent the oil droplets from encapsulating subsequent pollutants and reagents and increasing the system processing burden.

[0073] Neutralizers, flocculants and coagulants are further added to gather the suspended matter and colloidal matter in the water, and the suspended matter, finely dispersed oil adsorbed on the suspended matter and part of the COD are removed by the action of dissolved air and water. After these two steps, the oil in the sewage is basically removed.

[0074] Then, under the action of softeners, flocculants and coagulants, COD, suspended solids, heavy metals and other pollutants in the wastewater are further precipitated and removed, removing most of the heavy metal ions and thereby reducing the hardness of the water.

[0075] In order to further reduce the sewage concentration passing through the nanofiltration membrane, the remaining COD is strongly oxidized and degraded by ozone, and the degraded sewage enters the multi-media filter 310. The COD in the sewage entering the SNF membrane device 330 is controlled to be ≤60 mg / L to avoid the impact of excessive COD content on the nanofiltration membrane.

[0076] The embodiment targets the wastewater from the filter production line, and its components and parameters are shown in Table 1:

[0077] The embodiment targets the wastewater from the filter production line, and its components and parameters are shown in Table 1:

[0078] Table 1 Composition and parameters of wastewater from filter production line

[0079] Components concentration Suspended matter 34~51mg / L Chemical oxygen demand (COD) 80~151mg / L 5-day biochemical oxygen demand 35.1mg / L Ammonia nitrogen 0.043~1.10mg / L Total Phosphorus 0.18~0.29mg / L iron 0.21~1.11mg / L Zinc 0.05~0.24mg / L nickel <0.05mg / L

[0080] The utility model is a treatment method for filter production line sewage. The components of the sewage are shown in Table 1. The characteristics of filter production line sewage are poor biodegradability, high suspended matter concentration and high hardness. Therefore, the utility model adopts the method of pretreatment + SNF membrane system to solve the problem in view of the characteristics. The final produced water meets the process and product water standard requirements in "Water Quality for Industrial Water Used in Urban Wastewater Recycling" (GB / T 19923-2005).

[0081] Example 1

[0082] A zero-discharge treatment device for wastewater of a filter production line comprises an oil removal unit 100, a reaction unit 200, a filtration unit 300, a water production unit 400, a dosing unit 500, a sludge treatment unit 600 and a concentrated water treatment unit 700. The oil removal unit 100, the reaction unit 200, the filtration unit 300 and the water production unit 400 are connected in sequence, the dosing unit 500 is respectively connected to the reaction unit 200 and the filtration unit 300, the sludge treatment unit 600 is respectively connected to the reaction unit 200 and the filtration unit 300, and the concentrated water treatment unit 700 is connected to the rear end of the filtration unit 300.

[0083] The oil removal unit 100 includes an oil separation regulating tank 110, and the oil separation regulating tank 110 is equipped with a lifting pump for inputting sewage into the reaction unit 200. The oil separation regulating tank 110 is a multi-grid oil separation regulating tank 110 with a rectangular plane, which is provided with a plurality of tank bodies, and the side wall of the oil separation regulating tank 110 is provided with a water hole, and the water hole is arranged below the liquid surface. Sewage flows between adjacent oil separation regulating tanks 110 through the water hole. The oil separation regulating tank 110 is used to remove large-volume suspended matter and oil floating on the surface in the sewage, and then the sewage is lifted to the flotation tank 210 through a pipeline by the lifting pump for treatment.

[0084] The oil removal unit 100 includes an oil separation regulating tank 110, which is a multi-grid oil separation regulating tank 110 with a rectangular plane. It is provided with a plurality of tank bodies. The side wall of the oil separation regulating tank 110 is provided with water holes, and wastewater flows between the plurality of oil separation regulating tanks 110 through the water holes.

[0085] The reaction unit 200 includes an air flotation tank 210, a softening and coagulation tank 220 and an ozone catalytic oxidation tank 230 which are connected in sequence.

[0086] The flotation tank 210 includes a tank body 211 and a gas dissolving device 212. The gas dissolving device 212 includes a gas dissolving tank 2121. A gas flotation gas dissolving pump 2122 is provided on the pipeline between the gas dissolving tank 2121 and the tank body 211. The gas flotation gas dissolving pump 2122 pressurizes the gas in the gas dissolving tank 2121 and passes it into the tank body 211. The gas and solution are stirred at high speed by the gas flotation gas dissolving pump 2122 to form a large number of tiny bubbles. The tiny bubbles are attached to the pollutants formed by coagulation, so that the pollutants float to the surface. A scraping device 213 is also provided in the flotation tank 210. The scraping device 213 includes at least one scraping plate. The scraping plate is located above the liquid surface of the flotation tank 210. The scraping plate is operated by a driving device to scrape the impurities floating on the surface into the sludge tank 610, so as to remove the excess suspended matter and oil in the water at a deeper level. The treated sewage overflows from the pipeline to the softening coagulation tank 220. A sludge pool 215 is provided below the flotation pool 210 to receive impurities scraped off by the scraper.

[0087] The softening coagulation tank 220 includes a reaction tank 221 and a sedimentation tank 222. The reaction tank 221 and the sedimentation tank 222 are separated by a baffle. A water hole is provided on the baffle. Wastewater flows between the reaction tank 221 and the sedimentation tank 222 through the water hole. The sedimentation tank 222 is used to gravity settle the flocculent precipitate generated in the reaction tank 221. The bottom of the sedimentation tank 222 is connected to the sludge tank 215 through a pipeline. The reaction tank 221 is provided with a first stirring device 214 to mix the wastewater and the reaction reagent evenly. The sedimentation tank 222 is provided with mutually parallel inclined pipes, which are preferably made of PP material. The inclined pipes are used to partition the wastewater and the reaction reagent in the sedimentation tank 222 to reduce the accumulation and enrichment of precipitation and affect the precipitation efficiency. The divalent metal ions in the sewage are removed to reduce the hardness of the sewage. The supernatant after sedimentation and separation overflows to the ozone catalytic oxidation tank 230 through the overflow weir.

[0088] The ozone catalytic oxidation tank 230 is separated from the sedimentation tank 222 by a baffle, and an overflow weir is provided on the upper part of the baffle. The ozone catalytic oxidation tank 230 is provided with an ozone generator 231 for oxidative removal of organic matter. Through the strong oxidizing property of ozone, the organic matter remaining in the sewage is oxidized so that it can meet the reuse water standard. The ozone catalytic oxidation tank 230 is connected to the internal circulation pump 232, and the internal circulation pump 232 is circulated to allow ozone and sewage to fully react and improve the treatment efficiency. Finally, the treated sewage enters the filter unit 300 for filtration.

[0089] The filtration unit 300 includes a multi-media filter 310 and a SNF membrane device 330 connected in sequence. The multi-media filter 310 includes a cylinder connected in sequence. A filter material is arranged in the cylinder. The filter material can be quartz sand, anthracite, activated carbon, magnetite, garnet, porous ceramics, plastic balls, etc., to achieve the filtration and adsorption of tiny suspended matter and ensure the stable operation of the post-processing system. In Example 1, the multi-media filter 310 includes two tanks connected in sequence. The medium in tank one is quartz sand with different gaps, and the medium in tank two is activated carbon with different mesh sizes. The quartz sand is used to filter suspended matter in water, and the activated carbon is used to adsorb organic matter and heavy metals.

[0090] The SNF membrane device 330 includes a precision filter 332 and a SNF membrane assembly 334, which are used to remove pollutants such as COD, ammonia nitrogen, and divalent salts in the wastewater. The water produced by the SNF membrane system can be reused after entering the water production tank. Among them, a SNF booster pump 331 is provided in front of the precision filter 332 to increase the pressure of the water entering the precision filter 332, and a SNF high-pressure pump 333 is provided in front of the SNF membrane assembly 334 to increase the pressure of the water entering the SNF membrane assembly 334.

[0091] A raw water tank 320 is provided between the multi-media filter 310 and the SNF membrane device 330 to store water after ozone catalytic oxidation. Since the water after ozone catalytic oxidation needs to pass through the multi-media filter 310, and the multi-media filter 310 cannot be directly connected to the subsequent system, a raw water tank 320 is provided to store water after ozone catalytic oxidation. At the same time, the water output from ozone catalytic oxidation needs to stay for a certain period of time to ensure that the quality of the subsequent influent water remains stable.

[0092] The SNF membrane device 330 is connected to the produced water tank 410, and the produced water that meets the reuse water standard is reused in the production process through the reuse water pump 411.

[0093] The dosing unit 500 includes several dosing tanks, including a first dosing tank filled with a neutralizer, a second dosing tank filled with a flocculant, a third dosing tank filled with a coagulant aid, a fourth dosing tank filled with a softener, a fourth dosing tank filled with a scale inhibitor and a sixth dosing tank filled with a reducing agent. The first dosing tank is connected to the flotation tank, the second dosing tank is respectively connected to the flotation tank 210 and the softening coagulation tank 220, the third dosing tank is respectively connected to the flotation tank 210 and the softening coagulation tank 220, the fourth dosing tank is connected to the softening coagulation tank 220, the fifth dosing tank and the sixth dosing tank are connected to the SNF membrane device 330, and valves are provided on the dosing pipelines of the dosing tanks to control the dosing flow rate.

[0094] The sludge treatment unit 600 includes a plate-frame filter press 610, and the plate-frame filter press 620 is connected to the sludge pool 215. The plate-frame filter press 620 filters the sludge and outsources the filtered sludge for treatment. Furthermore, during the plate-frame filter pressing process, the air compressor 611 drives the pneumatic diaphragm pump 612 to achieve rapid sludge filtration.

[0095] The concentrated water treatment unit 700 includes a concentrated water tank 710, which is connected to the SNF membrane assembly 334 and receives concentrated water processed by the SNF membrane assembly 334. One end of the concentrated water tank 710 is connected to the flotation tank 210. A part of the concentrated water in the concentrated water tank 710 is passed into the flotation tank 210 and is further processed through the reaction unit 200 and the filtration unit 300. The other end of the concentrated water tank 710 is connected to the concentrated water circulation tank 720. When the system is overloaded and cannot withstand the reprocessing of concentrated water, the concentrated water in the concentrated water tank 710 is passed into the concentrated water circulation tank 720. The concentrated water circulation tank 720 is sequentially connected to the low-temperature evaporation concentrator 730 and the cooling tower 740. During the processing, the concentrated water is cooled by the low-temperature evaporation concentrator 730, and salt is precipitated at a low temperature. The temperature is controlled at about 180°C.

[0096] The flotation tank 210 is provided with a first stirring device 214, and the reaction tank 221 is provided with a second stirring device 2211, which are used to mix the reactants evenly;

[0097] The flotation tank 210 is provided with an online pH meter to control the pH of the wastewater in the reaction unit 200 to be between 7 and 8.

[0098] Example 2

[0099] A zero-discharge treatment device for wastewater of a filter production line comprises an oil removal unit 100, a reaction unit 200, a filtration unit 300, a water production unit 400, a dosing unit 500, a sludge treatment unit 600 and a concentrated water treatment unit 700. The oil removal unit 100, the reaction unit 200, the filtration unit 300 and the water production unit 400 are connected in sequence, the dosing unit 500 is respectively connected to the reaction unit 200 and the filtration unit 300, the sludge treatment unit 600 is respectively connected to the reaction unit 200 and the filtration unit 300, and the concentrated water treatment unit 700 is connected to the rear end of the filtration unit 300.

[0100] The oil removal unit 100 includes an oil separation regulating tank 110, and the oil separation regulating tank 110 is equipped with a lifting pump for inputting sewage into the reaction unit 200. The oil separation regulating tank 110 is a multi-grid oil separation regulating tank 110 with a rectangular plane, which is provided with a plurality of tank bodies, and the side wall of the oil separation regulating tank 110 is provided with a water hole, and the water hole is arranged below the liquid surface. Sewage flows between adjacent oil separation regulating tanks 110 through the water hole. The oil separation regulating tank 110 is used to remove large-volume suspended matter and oil floating on the surface in the sewage, and then the sewage is lifted to the flotation tank 210 through a pipeline by the lifting pump for treatment.

[0101] The oil removal unit 100 includes an oil separation regulating tank 110, which is a multi-grid oil separation regulating tank 110 with a rectangular plane. It is provided with a plurality of tank bodies. The side wall of the oil separation regulating tank 110 is provided with water holes, and wastewater flows between the plurality of oil separation regulating tanks 110 through the water holes.

[0102] The reaction unit 200 includes an air flotation tank 210, a softening and coagulation tank 220 and an ozone catalytic oxidation tank 230 which are connected in sequence.

[0103] The flotation tank 210 includes a tank body 211 and a gas dissolving device 212. The gas dissolving device 212 includes a gas dissolving tank 2121. A gas flotation gas dissolving pump 2122 is provided on the pipeline between the gas dissolving tank 2121 and the tank body 211. The gas flotation gas dissolving pump 2122 pressurizes the gas in the gas dissolving tank 2121 and passes it into the tank body 211. The gas and solution are stirred at high speed by the gas flotation gas dissolving pump 2122 to form a large number of tiny bubbles. The tiny bubbles are attached to the pollutants formed by coagulation, so that the pollutants float to the surface. A scraping device 213 is also provided in the flotation tank 210. The scraping device 213 includes at least one scraping plate. The scraping plate is located above the liquid surface of the flotation tank 210. The scraping plate is operated by a driving device to scrape the impurities floating on the surface into the sludge tank 610, so as to remove the excess suspended matter and oil in the water at a deeper level. The treated sewage overflows from the pipeline to the softening coagulation tank 220. A sludge pool 215 is provided below the flotation pool 210 to receive impurities scraped off by the scraper.

[0104] The softening coagulation tank 220 includes a reaction tank 221 and a sedimentation tank 222. The reaction tank 221 and the sedimentation tank 222 are separated by a baffle. A water hole is provided on the baffle. Wastewater flows between the reaction tank 221 and the sedimentation tank 222 through the water hole. The sedimentation tank 222 is used to gravity settle the flocculent precipitate generated in the reaction tank 221. The bottom of the sedimentation tank 222 is connected to the sludge tank 215 through a pipeline. The reaction tank 221 is provided with a first stirring device 214 to mix the wastewater and the reaction reagent evenly. The sedimentation tank 222 is provided with mutually parallel inclined pipes, which are preferably made of PP material. The inclined pipes are used to partition the wastewater and the reaction reagent in the sedimentation tank 222 to reduce the accumulation and enrichment of precipitation and affect the precipitation efficiency. The divalent metal ions in the sewage are removed to reduce the hardness of the sewage. The supernatant after sedimentation and separation overflows to the ozone catalytic oxidation tank 230 through the overflow weir.

[0105] The ozone catalytic oxidation tank 230 is separated from the sedimentation tank 222 by a baffle, and an overflow weir is provided on the upper part of the baffle. The ozone catalytic oxidation tank 230 is provided with an ozone generator 231 for oxidative removal of organic matter. Through the strong oxidizing property of ozone, the organic matter remaining in the sewage is oxidized so that it can meet the reuse water standard. The ozone catalytic oxidation tank 230 is connected to the internal circulation pump 232, and the internal circulation pump 232 is circulated to allow ozone and sewage to fully react and improve the treatment efficiency. Finally, the treated sewage enters the filter unit 300 for filtration.

[0106] The filtration unit 300 includes a multi-media filter 310 and a SNF membrane device 330 connected in sequence. The multi-media filter 310 includes a cylinder connected in sequence. A filter material is arranged in the cylinder. The filter material can be quartz sand, anthracite, activated carbon, magnetite, garnet, porous ceramics, plastic balls, etc., to achieve the filtration and adsorption of tiny suspended matter and ensure the stable operation of the post-processing system. In Example 1, the multi-media filter 310 includes two tanks connected in sequence. The medium in tank one is quartz sand with different gaps, and the medium in tank two is activated carbon with different mesh sizes. The quartz sand is used to filter suspended matter in water, and the activated carbon is used to adsorb organic matter and heavy metals.

[0107] The SNF membrane device 330 includes a precision filter 332 and a SNF membrane assembly 334, which are used to remove pollutants such as COD, ammonia nitrogen, and divalent salts in the wastewater. The water produced by the SNF membrane system can be reused after entering the water production tank. Among them, a SNF booster pump 331 is provided in front of the precision filter 332 to increase the pressure of the water entering the precision filter 332, and a SNF high-pressure pump 333 is provided in front of the SNF membrane assembly 334 to increase the pressure of the water entering the SNF membrane assembly 334.

[0108] A raw water tank 320 is provided between the multi-media filter 310 and the SNF membrane device 330 to store water after ozone catalytic oxidation. Since the water after ozone catalytic oxidation needs to pass through the multi-media filter 310, and the multi-media filter 310 cannot be directly connected to the subsequent system, a raw water tank 320 is provided to store water after ozone catalytic oxidation. At the same time, the water output from ozone catalytic oxidation needs to stay for a certain period of time to ensure that the quality of the subsequent influent water remains stable.

[0109] The SNF membrane device 330 is connected to the produced water tank 410, and the produced water that meets the reuse water standard is reused in the production process through the reuse water pump 411.

[0110] The dosing unit 500 includes several dosing tanks, including a first dosing tank filled with a neutralizer, a second dosing tank filled with a flocculant, a third dosing tank filled with a coagulant aid, a fourth dosing tank filled with a softener, a fourth dosing tank filled with a scale inhibitor and a sixth dosing tank filled with a reducing agent. The first dosing tank is connected to the flotation tank, the second dosing tank is respectively connected to the flotation tank 210 and the softening coagulation tank 220, the third dosing tank is respectively connected to the flotation tank 210 and the softening coagulation tank 220, the fourth dosing tank is connected to the softening coagulation tank 220, the fifth dosing tank and the sixth dosing tank are connected to the SNF membrane device 330, and valves are provided on the dosing pipelines of the dosing tanks to control the dosing flow rate.

[0111] The sludge treatment unit 600 includes a plate-frame filter press 610, and the plate-frame filter press 620 is connected to the sludge pool 215. The plate-frame filter press 620 filters the sludge and outsources the filtered sludge for treatment. Furthermore, during the plate-frame filter pressing process, the air compressor 611 drives the pneumatic diaphragm pump 612 to achieve rapid sludge filtration.

[0112] The concentrated water treatment unit 700 includes a concentrated water tank 710, which is connected to the SNF membrane assembly 334 and receives concentrated water processed by the SNF membrane assembly 334. One end of the concentrated water tank 710 is connected to the flotation tank 210. A part of the concentrated water in the concentrated water tank 710 is passed into the flotation tank 210 and is further processed through the reaction unit 200 and the filtration unit 300. The other end of the concentrated water tank 710 is connected to the concentrated water circulation tank 720. When the system is overloaded and cannot withstand the reprocessing of concentrated water, the concentrated water in the concentrated water tank 710 is passed into the concentrated water circulation tank 720. The concentrated water circulation tank 720 is sequentially connected to the low-temperature evaporation concentrator 730 and the cooling tower 740. During the processing, the concentrated water is cooled by the low-temperature evaporation concentrator 730, and salt is precipitated at a low temperature. The temperature is controlled at about 180°C.

[0113] The flotation tank 210 is provided with a first stirring device 214, and the reaction tank 221 is provided with a second stirring device 2211, which are used to mix the reactants evenly;

[0114] The flotation tank 210 is provided with an online pH meter to control the pH of the wastewater in the reaction unit 200 to be between 7 and 8.

[0115] In the prior art, biochemical treatment is generally used for sewage treatment, but biochemical treatment relies on the action of microorganisms, which are greatly affected by the seasons, have high requirements for the environment, and are unstable in operation. The sewage from the filter production line targeted by this application has a high concentration of heavy metals (iron, zinc, nickel), which toxicize microorganisms and affect the sewage treatment effect. In addition, microorganisms cannot regenerate, and the post-treatment process is complicated.

[0116] The present application adopts the process of oil separation treatment → coagulation flotation → softening coagulation → ozone oxidation → filtration and adsorption → nanofiltration for the treatment of wastewater from the filter production line. Compared with the existing technology, it adopts a non-biochemical treatment method.

[0117] The wastewater of the filter production line contains oil, suspended solids 34-51 mg / L, ammonia nitrogen 0.043-1.10 mg / L, total phosphorus 0.18-0.29 mg / L, iron ion 0.21-1.11 mg / L, zinc ion 0.05-0.24 mg / L, nickel ion <0.05 mg / L, COD 80-151 mg / L, and five-day biochemical oxygen demand 35.1 mg / L. First, oil separation treatment is used to remove oil droplets with a particle size greater than 100 nm in the wastewater to prevent the oil droplets from encapsulating subsequent pollutants and reagents and increasing the system processing burden.

[0118] Neutralizers, flocculants and coagulants are further added to gather the suspended matter and colloidal matter in the water, and the suspended matter, finely dispersed oil adsorbed on the suspended matter and part of the COD are removed by the action of dissolved air and water. After these two steps, the oil in the sewage is basically removed.

[0119] Then, under the action of softeners, flocculants and coagulants, COD, suspended solids, heavy metals and other pollutants in the wastewater are further precipitated and removed, removing most of the heavy metal ions and thereby reducing the hardness of the water.

[0120] In order to further reduce the sewage concentration passing through the nanofiltration membrane, the remaining COD is strongly oxidized and degraded by ozone, and the degraded sewage enters the multi-media filter 310. The COD in the sewage entering the SNF membrane device 330 is controlled to be ≤60 mg / L to avoid the impact of excessive COD content on the nanofiltration membrane.

[0121] The agents appearing in the embodiment include: a neutralizing agent configured at a mass concentration of 10%;

[0122] The mass concentration of flocculant configuration is 0.1%;

[0123] The mass concentration of the coagulant aid is 10%;

[0124] The mass concentration of the softener configuration is 10%;

[0125] The antiscalant is configured with a mass concentration of 10%; wherein the antiscalant comprises an organic polymer, such as a phosphorus-containing small molecule organic polymer;

[0126] The mass concentration of the reducing agent is 10%.

[0127] Example 3

[0128] During operation, the SNF membrane device 330 needs to be cleaned regularly, or there are too many pollutants deposited in the device. In order to prevent the pollutants from clogging the membrane and affecting the reaction process, the membrane is cleaned with an antiscalant and a reducing agent. During cleaning, the introduction of sewage into the SNF membrane device 330 is stopped. In this embodiment, a phosphorus-containing organic polymer is used as an antiscalant, and sodium bisulfite is used as a reducing agent. The introduction amount of the antiscalant and the reducing agent is 1:1.

Claims

1. A filter production line wastewater zero discharge treatment device, characterized in that: The invention comprises an oil removal unit (100), a reaction unit (200), a filtering unit (300), a water production unit (400), a dosing unit (500), a sludge treatment unit (600) and a concentrated water treatment unit (700), wherein the oil removal unit (100), the reaction unit (200), the filtering unit (300) and the water production unit (400) are connected in sequence, the dosing unit (500) is connected to the reaction unit (200) and the filtering unit (300) respectively, the sludge treatment unit (600) is connected to the reaction unit (200) and the filtering unit (300) respectively, and the concentrated water treatment unit (700) is connected to the rear end of the filtering unit (300); Wherein, the reaction unit (200) comprises an air flotation tank (210), a softening and coagulation tank (220) and an ozone catalytic oxidation tank (230) which are connected in sequence; The filtration unit (300) comprises a multi-media filter (310) and an SNF membrane device (330) connected in sequence, the SNF membrane device (330) comprises a precision filter (332) and an SNF membrane assembly (334), an SNF booster pump (331) is provided in front of the precision filter (332), and an SNF high-pressure pump (333) is provided in front of the SNF membrane assembly (334); The concentrated water treatment unit (700) comprises a concentrated water barrel (710), the concentrated water barrel (710) being connected to the filtering unit (300), one end of the concentrated water barrel (710) being connected to the flotation tank (210), and the other end being connected to a concentrated water circulation barrel (720), and the concentrated water circulation barrel (720) being connected in sequence to a low-temperature evaporation concentrator (730) and a cooling tower (740).

2. The device according to claim 1, characterized in that The oil removal unit (100) comprises an oil separation regulating tank (110), and a water passage hole is provided on a side wall of the oil separation regulating tank (110).

3. The device according to claim 1, characterized in that The flotation tank (210) comprises a tank body (211) and a gas dissolving device (212); the gas dissolving device (212) comprises a gas dissolving tank (2121) and a gas flotation gas dissolving pump (2122) connected to the gas dissolving tank (2121); the gas dissolving tank (2121) passes gas into the tank body (211) below the liquid surface through the gas flotation gas dissolving pump (2122).

4. The device according to claim 3, characterized in that A scraping device (213) is also provided in the flotation tank (210). The scraping device (213) comprises at least one scraping plate. The scraping plate is located above the liquid surface of the flotation tank (210). A sludge tank (610) is provided below the flotation tank (210).

5. The device according to claim 1, characterized in that The softening coagulation tank (220) comprises a reaction tank (221) and a sedimentation tank (222); the reaction tank (221) and the sedimentation tank (222) are separated by a baffle plate, a water hole is provided on the baffle plate, and the bottom of the sedimentation tank (222) is connected to the sludge treatment unit (600) through a pipeline.

6. The device according to claim 5, characterized in that An ozone generator (231) is provided in the ozone catalytic oxidation pool (230), and the ozone catalytic oxidation pool (230) and the sedimentation pool (222) are separated by a baffle, and an overflow weir is provided on the upper part of the baffle.

7. The device according to claim 4, characterized in that The sludge treatment unit (600) includes a plate and frame filter press (620), and the plate and frame filter press (620) is connected to the sludge tank (610).

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