Industrial cleaning wastewater purification system

Abstract

The present invention discloses an industrial cleaning wastewater purification system, comprising a raw water collection tank, a biochemical treatment unit connected to the raw water collection tank, a membrane bioreactor unit connected to the biochemical treatment unit, a filtration and sterilization system connected to the membrane bioreactor unit, and a sludge treatment system connected to the membrane bioreactor unit. Wastewater treated by the filtration and sterilization system enters a phosphorus removal resin unit and a nitrogen removal resin unit. Resin regeneration wastewater generated by the phosphorus removal resin unit and the nitrogen removal resin unit is treated in a low-temperature evaporator and then enters the membrane bioreactor unit. The phosphorus removal resin unit and the nitrogen removal resin unit of the present invention can effectively remove phosphorus and nitrogen from the wastewater. The generated resin regeneration wastewater is treated in a low-temperature evaporator, and the condensate is discharged into the membrane bioreactor unit for treatment. The concentrated wastewater is collected and outsourced for treatment. In this way, the regeneration wastewater after the removal of phosphorus and nitrogen can be effectively purified.

Description

Technical Field

[0001] The present invention relates to wastewater treatment, in particular to the treatment of industrial cleaning wastewater. Background Art

[0002] Surfactants are the primary pollutant in industrial cleaning wastewater. Once surfactants enter the water, they combine with other pollutants to form dispersed colloidal particles, significantly impacting the physicochemical and biochemical properties of both industrial and domestic wastewater. Therefore, surfactant treatment is a common requirement for industrial cleaning wastewater treatment. The treatment of industrial cleaning wastewater containing surfactants is crucial for resource conservation, maintaining ecological balance, and promoting economic development. Industrial cleaning wastewater comes from a wide range of sources, including machining, electronics, metallurgy, surface coating, laundry, chemicals, textiles, and other industries, as well as daily life. The surfactants in wastewater are inherently toxic, with chronic effects on animals, plants, and humans. They can also reduce oxygen transfer rates in water, hindering self-purification. Foam generated by industrial cleaning wastewater can also affect environmental hygiene and aesthetics. Furthermore, surfactants inhibit and kill microorganisms and inhibit the degradation of other toxic substances, contributing to eutrophication in lakes and rivers.

[0003] Patent document with publication number CN114573176A discloses a method for treating industrial cleaning wastewater to meet discharge standards. The treatment method includes the following steps: the industrial cleaning wastewater is sequentially subjected to wastewater collection, ceramic membrane pretreatment, primary nanofiltration treatment, secondary nanofiltration treatment, and vacuum evaporation and drying treatment, and then discharged after treatment.

[0004] The above patent document has a good treatment effect on industrial cleaning wastewater containing hydrophilic anionic surfactants, especially MADS, but cannot effectively remove phosphorus and nitrogen in the wastewater. Summary of the Invention

[0005] The technical problems solved by the present invention are: how to effectively remove phosphorus and nitrogen from wastewater, and how to treat the regenerated wastewater after the removal of phosphorus and nitrogen.

[0006] In order to solve the above technical problems, the present invention provides the following technical solutions: an industrial cleaning wastewater purification system, comprising a raw water collection tank, a biochemical treatment unit connected to the raw water collection tank, a membrane bioreactor unit connected to the biochemical treatment unit, a filtration and sterilization system connected to the membrane bioreactor unit, and a sludge treatment system connected to the membrane bioreactor unit. The wastewater treated by the filtration and sterilization system enters the phosphorus removal resin unit and the nitrogen removal resin unit, and the resin regeneration waste liquid generated by the phosphorus removal resin unit and the nitrogen removal resin unit enters the membrane bioreactor unit after being treated in a low-temperature evaporator.

[0007] The biochemical treatment unit consists of two sections: an anaerobic section and an aerobic section. The anaerobic section achieves a high organic matter removal rate in a short period of time and at a relatively high load. It also breaks down recalcitrant organic macromolecules into easily degradable small organic molecules, significantly improving the biodegradability and solubility of the wastewater. The aerobic section is a biological treatment device that primarily utilizes a biofilm process and also incorporates activated sludge. By providing an oxygen source, organic matter in the wastewater is adsorbed and degraded by microorganisms, resulting in purified water quality. The effluent enters the membrane bioreactor unit.

[0008] In the membrane bioreactor unit, the presence of the biofilm greatly improves the system's ability to separate solids and liquids, thereby significantly improving the system's effluent, water quality, and volumetric load. The water quality standards after membrane treatment are high, and after disinfection, it finally forms high-quality reclaimed water with high water quality and biosafety, which can be directly used as a new water source. Due to the filtering effect of the membrane, microorganisms are completely retained in the membrane bioreactor, achieving a complete separation between the hydraulic retention time and the activated sludge age, eliminating the sludge expansion problem in the traditional activated sludge process. The membrane bioreactor has the advantages of high pollutant removal efficiency, strong nitrification capacity, and can simultaneously carry out nitrification, denitrification, and denitrification with good effects, stable effluent water quality, low residual sludge production, compact equipment, small footprint (only 1 / 3-1 / 2 of the traditional process), convenient incremental expansion, high degree of automation, and simple operation.

[0009] The sludge from the membrane biological reaction unit is pumped into the sludge treatment system, and the wastewater from the membrane biological reaction unit is treated by the filtration and sterilization system before entering the phosphorus removal resin unit and the nitrogen removal resin unit.

[0010] While chemical precipitation is relatively efficient, it consumes chemicals and produces large amounts of chemical sludge, making treatment relatively expensive. Traditional biological treatment processes are simple to operate, but their phosphorus removal efficiency is low, making it difficult to meet effluent requirements. Phosphorus removal resins are based on premium polystyrene acrylic acid-based strong alkaline anion phosphorus exchange resins containing Type I quaternary ammonium functional groups with excellent physical and chemical stability. They are suitable for phosphate removal. They offer a longer service life, more lasting and stable results, and can remove all valence states of phosphorus (orthophosphorus, hypophosphorus, etc.) from wastewater.

[0011] Nitrate removal resins are macroporous, strongly basic, quaternary amine-functionalized resins. Increasing the number of carbon atoms surrounding the nitrogen atom in the resin's NR3+ functional group increases the resin's selectivity for nitrates. The order of selectivity for nitrates is: HCO3- < Cl- ​​< SO42- < NO3-. Nitrate removal resins achieve a high treatment accuracy, achieving a total nitrogen content of 1 ppm in various wastewaters, consistently meeting surface nitrogen standards. Ammonia removal resins are nuclear-grade, strongly acidic resins with sulfonic acid groups. They are highly effective in removing ammonia nitrogen from evaporator condensate and post-membrane water, as well as treating trace amounts of ammonia nitrogen in post-biochemical wastewater from industries such as aquaculture and the chemical industry, ensuring stable effluent and meeting discharge standards. Currently, these resins are widely used and have achieved excellent results in deep ammonia nitrogen treatment of landfill leachate using DTRO membranes, post-RO membrane ammonia nitrogen treatment, evaporation condensate, coal mine water, the battery and electronics industry, domestic sewage, aquaculture water, chemical wastewater, aquaculture wastewater, and drinking water.

[0012] The resin regeneration waste liquid generated by the phosphorus removal resin unit and the nitrogen removal resin unit enters the low-temperature evaporator for treatment. The low-temperature evaporator treats a variety of polluted wastewater or water containing oil products, especially wastewater from cutting fluid, cleaning wastewater, surface treatment wastewater, high-salt wastewater, flaw detection wastewater or other production process water, etc.

[0013] The phosphorus removal resin unit and nitrogen removal resin unit of the present invention can effectively remove phosphorus and nitrogen from wastewater. The generated resin regeneration wastewater is treated in a low-temperature evaporator, and the condensate is discharged into the membrane bioreactor unit for treatment. The concentrated wastewater is collected and outsourced for treatment. In this way, the regeneration wastewater after the removal of phosphorus and nitrogen can be effectively purified. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention will be further described below with reference to the accompanying drawings:

[0015] Figure 1 This is a wastewater treatment flow chart;

[0016] Figure 2 is a schematic diagram of the raw water collection tank;

[0017] Figure 3 This is a schematic diagram of a cleaning robot;

[0018] Figure 4 This is a top view of the cleaning robot;

[0019] Figure 5 Schematic diagram of a brush barrel;

[0020] Figure 6 It is a top view of the brush barrel.

[0021] Explanation of symbols in the figure:

[0022] 10. Raw water collection tank;

[0023] 20. Large filter mesh; 21. Articulated shaft; 22. Electromagnet;

[0024] 30. Cleaning robot; 31. Top frame; 32. Small filter mesh; 33. Brush cylinder; 330. Brush cylinder seal; 34. Small motor; 340. Motor shaft; 35. Support legs; 350. Roller. DETAILED DESCRIPTION

[0025] like Figure 1 , an industrial cleaning wastewater purification system, including a raw water collection tank, a biochemical treatment unit connected to the raw water collection tank, a membrane bioreactor unit connected to the biochemical treatment unit, a filtration and sterilization system connected to the membrane bioreactor unit, and a sludge treatment system connected to the membrane bioreactor unit. The wastewater treated by the filtration and sterilization system enters the phosphorus removal resin unit and the nitrogen removal resin unit. The resin regeneration waste liquid generated by the phosphorus removal resin unit and the nitrogen removal resin unit is treated in a low-temperature evaporator and then enters the membrane bioreactor unit.

[0026] Combine Figures 2 to 6 The raw water collection tank 10 is equipped with a large filter mesh 20, located in the lower middle portion of the tank. The tank's water inlet is located below the large filter mesh, and the tank's water outlet is located above the large filter mesh. The center of the large filter mesh is hinged to the tank's sidewall via a hinge shaft 21. This hinge shaft is connected to a motor mounted on the tank's outer wall. An electromagnet 22 is mounted on the tank's outer wall, near the large filter mesh.

[0027] Wastewater is pumped into the raw water collection tank 10. Lighter materials float upward, blocked by the large filter mesh. Heavier materials sink, blocked by the large filter mesh 20. Even if impacted by the water flow, they cannot break through the filter mesh. This provides a preliminary filtration of the wastewater, and the wastewater above the large filter mesh is pumped away and sent to the biochemical treatment unit.

[0028] To remove light-density objects from beneath the large filter, the filter needs to be regularly flipped. Specifically, when electromagnet 22 is de-energized, the motor is energized, driving the large filter 20 to rotate 180 degrees. During this rotation, light-density objects float upward through the filter 20. After rotating 180 degrees, the large filter is back in a horizontal position, and electromagnet 22 is energized to attract them, securing the large filter 20.

[0029] As an improvement, the large filter mesh is equipped with a cleaning robot 30. The robot consists of a top frame 31, a small filter mesh 32 mounted on the top frame, a brush cylinder 33 mounted below the top frame, a small motor 34 housed in the brush cylinder, and legs 35 located at the four corners of the top frame. When idle, the cleaning robot is suspended from the side wall of the raw water collection tank, away from the large filter mesh 20. When the large filter mesh needs to be cleaned, a worker lowers the robot.

[0030] The small motor 34 has its own battery and is remotely controlled. The inner cavity of the brush barrel 33 is closed on one side and open on the other. After the small motor and accompanying control unit are installed in the inner cavity of the brush barrel, it is sealed. The motor shaft 340 and charging connector of the small motor 34 are exposed and waterproofed. The motor shaft of the small motor is connected to the brush barrel 33. The rotation of the motor shaft 340 drives the brush barrel to rotate. The brush barrel contacts the large filter mesh 20 and moves along the large filter mesh while cleaning it. The legs at the four corners of the top frame support the cleaning robot, and rollers 350 are provided at the bottom of the legs.

[0031] The dirt attached to the large filter mesh is the target of cleaning. After cleaning, this dirt can mix into the filtered wastewater, reducing the effectiveness of wastewater filtration. Therefore, it is necessary to recover the cleaned dirt. Specifically, after the brush cylinder cleans the dirt from the large filter mesh, the water in the raw water collection tank flows from bottom to top. Therefore, the cleaned dirt is carried to the small filter mesh by the water flow, which blocks the dirt. After cleaning is completed, the cleaning robot is slowly hoisted, at a speed slower than the water flow, so that workers can remove the dirt from the small filter mesh.

[0032] like Figure 1 The biochemical treatment unit is divided into two sections: the anaerobic section and the aerobic section. The anaerobic section achieves a high organic matter removal rate in a short period of time and at a relatively high load. It also breaks down recalcitrant organic macromolecules into easily degradable small organic molecules, significantly improving the biodegradability and solubility of the wastewater. The aerobic section is a biological treatment device that primarily utilizes a biofilm process and also incorporates activated sludge. By providing an oxygen source, organic matter in the wastewater is adsorbed and degraded by microorganisms, resulting in purified water quality. The effluent enters the membrane bioreactor unit.

[0033] The membrane bioreactor (MBR) unit is a novel, highly efficient wastewater treatment process that combines high-efficiency membrane separation technology with the traditional activated sludge process. It utilizes a uniquely structured MBR membrane module placed in an aeration tank. After aerobic aeration and biological treatment, the water is filtered by a pump through the membrane and then withdrawn. The membrane separation device retains the activated sludge and macromolecular organic matter in the biochemical reactor. This significantly increases the activated sludge concentration, allowing the hydraulic retention time (HRT) and sludge retention time (SRT) to be independently controlled. Recalcitrant substances are continuously reacted and degraded within the reactor. The presence of the biofilm significantly enhances the system's solid-liquid separation capabilities, significantly improving the system's effluent quality and volumetric load. The treated water meets high quality standards (exceeding the national Class A standard). After disinfection, it produces high-quality reclaimed water with high water quality and biosafety, which can be directly used as a new water source. The membrane's filtration function completely retains microorganisms within the MBR, achieving a thorough decoupling of hydraulic retention time and activated sludge age, eliminating the sludge bulking problem associated with traditional activated sludge processes. Membrane bioreactors have the advantages of high pollutant removal efficiency, strong nitrification capacity, simultaneous nitrification, denitrification, good denitrification effect, stable effluent quality, low residual sludge production, compact equipment, small footprint (only 1 / 3-1 / 2 of traditional processes), convenient incremental expansion, high degree of automation, and simple operation.

[0034] The filtration and sterilization system includes a clean water tank connected to the membrane bioreactor unit, a sand / carbon filter connected to the clean water tank, a UV sterilizer connected to the sand / carbon filter, and an RO unit connected to the UV sterilizer unit. The RO unit is connected to a recycled water tank, which is then connected to a cooling tower. Water that meets the standards after treatment in the RO unit is transported through the recycled water tank to the cooling tower for on-site use. Water that does not meet the standards after treatment in the RO unit is treated in a phosphorus removal resin unit and a nitrogen removal resin unit.

[0035] The RO unit is connected to a concentrate collection tank, through which wastewater flows into the phosphorus removal resin unit and the nitrogen removal resin unit. After treatment, the water that meets the standards in the phosphorus removal and nitrogen removal resin units flows through the discharge tank into the municipal pipe network. The resin regeneration wastewater from the phosphorus removal and nitrogen removal resin units flows into the waste tank collection tank, where it then flows into the low-temperature evaporator.

[0036] Phosphorus removal resin is a premium polystyrene acrylic acid strong alkaline anion phosphorus removal exchange resin based on a Type I quaternary ammonium functional group with excellent physical and chemical stability, suitable for phosphate removal. It offers a longer service life, more lasting and stable results, and can remove phosphorus of all valence states (orthophosphorus, hypophosphorus, etc.) from wastewater. The phosphorus removal resin's treatment accuracy can reduce the phosphate content in various wastewaters to 0.1ppm, consistently meeting the surface Class III standards. It also boasts a large exchange capacity, with a minimum saturated adsorption capacity of 1.25meq / ml for orthophosphate reaching 36g / l. This specialized phosphorus removal resin adsorbs orthophosphorus, hypophosphorus, and hypophosphorus.

[0037] The nitrate removal resin is a macroporous, strongly basic quaternary amine-functionalized resin. Increasing the number of carbon atoms surrounding the nitrogen atom in the resin's NR3+ functional group improves the resin's selectivity for nitrates. The order of selectivity for nitrates is: HCO3- < Cl- ​​< SO42- < NO3-. The nitrate removal resin's treatment precision can achieve a total nitrogen content of 1 ppm in various wastewaters, consistently meeting surface nitrogen standards. The ammonia removal resin is a nuclear-grade, strongly acidic sulfonic acid-based resin. It is highly effective in removing ammonia nitrogen from evaporator condensate and post-membrane water, as well as treating trace amounts of ammonia nitrogen in post-biochemical wastewater from industries such as aquaculture and the chemical industry, ensuring stable effluent and meeting discharge standards. Currently, it has been widely used and achieved excellent results in the deep treatment of ammonia nitrogen in landfill leachate using DTRO membranes, post-RO membrane ammonia nitrogen treatment, evaporation condensate, coal mine water, the battery and electronics industry, domestic sewage, aquaculture water, chemical wastewater, aquaculture wastewater, and drinking water. This product offers advantages such as high precision, large exchange capacity, and a high concentration factor. Compared to current mainstream products, this product offers significant differentiation and is poised to become a global leader in the water treatment industry. Specific advantages include: First, high treatment precision, achieving ammonia nitrogen levels below 0.02 ppm; Second, a large exchange capacity, with a maximum practical exchange capacity of 30-40 g / l; Third, a high concentration factor, making it particularly advantageous for concentrated evaporation and recovery of ammonia nitrogen in the fertilizer industry, as the resin has a high concentration factor; Fourth, guaranteed post-membrane performance, ensuring compliance with ammonia nitrogen standards after RO and DTRO membranes; Fifth, comprehensive advantages, not only in specific parameters such as precision, but also in investment costs, operating costs, and floor space, making it the optimal process for deep ammonia nitrogen treatment.

[0038] Low-temperature evaporators are specifically designed for evaporation concentration and are particularly recommended for treating various contaminated wastewaters or water containing oil products, especially wastewater from cutting fluids, cleaning wastewater, surface treatment wastewater, high-salt wastewater, flaw detection wastewater, or other production process water. The specific treatment steps include: First, preheating. This step is fully automatic. When the raw water tank reaches the middle level, the water pump runs to create a vacuum, automatically filling the evaporator with water. The compressor runs to generate heat to heat the wastewater in the evaporation tank. Under the vacuum state, the wastewater temperature rises to around 30°C, and the wastewater begins to evaporate, completing the preheating process. Second, evaporation and concentration. The evaporation temperature is set at 35-40°C. The compressor compresses the refrigerant, generating heat. As the water evaporates rapidly, the refrigerant vaporizes through the expansion valve, absorbing heat and cooling. The vapor rises and meets the cold liquid, liquefying it into the water storage tank. The refrigerant absorbs heat and is compressed by the compressor to generate heat, further heating the wastewater. If bubbles rise during the evaporation process, the sensor detects it and defoaming agent is automatically added to eliminate the bubbles. After one cycle is completed, the concentrate begins to be discharged (the time of one cycle can be set); third, the concentrate is discharged. After one evaporation cycle is completed, the compression pump stops working, the pneumatic valve of the concentrate pipeline opens, the evaporation tank is pressurized, and the concentrate is pressed into the concentration barrel.

[0039] The low-temperature evaporator has the following advantages: the evaporation temperature is about 37 degrees, which is low and not easy to produce scale; the system runs automatically and only requires regular inspections; remote wireless monitoring can be installed; high concentration ratio; stable water output with good water quality; only 380V industrial electricity is required for energy, and no external auxiliary systems such as steam boilers or condensing towers are required; Weishengda patented vacuum tank structure; low-temperature heat pump technology is derived from the principle of industrial air conditioning, the technology is mature, and accessories can be purchased and maintained on the market at any time, with extremely low maintenance costs. All accessories do not need to be returned to the factory for repair

[0040] The sludge treatment system comprises a sludge relay tank connected to the membrane biological reaction unit and a filter press connected to the sludge relay tank.

[0041] The above contents are only preferred embodiments of the present invention. For ordinary technicians in this field, according to the concept of the present invention, there may be changes in the specific implementation methods and application scopes. The contents of this specification should not be understood as limiting the present invention.

Claims

1. An industrial cleaning wastewater purification system comprising a raw water collection tank, a biochemical treatment unit connected to the raw water collection tank, a membrane bioreactor unit connected to the biochemical treatment unit, a filtration and sterilization system connected to the membrane bioreactor unit, and a sludge treatment system connected to the membrane bioreactor unit, characterized in that: The wastewater treated by the filtration and sterilization system enters the phosphorus removal resin unit and the nitrogen removal resin unit, and the resin regeneration waste liquid generated by the phosphorus removal resin unit and the nitrogen removal resin unit is treated by a low-temperature evaporator and then enters the membrane biological reaction unit; A large filter mesh is provided in the raw water collection tank, located in the lower middle portion of the tank. The water inlet of the raw water collection tank is located below the large filter mesh, and the water outlet of the raw water collection tank is located above the large filter mesh. The middle portion of the large filter mesh is hinged to the side wall of the raw water collection tank via a hinge shaft, which is connected to a motor mounted on the outer wall of the raw water collection tank. An electromagnet is mounted on the outer wall of the raw water collection tank, located near the large filter mesh. The large filter mesh is equipped with a cleaning robot, which includes a top frame, a small filter mesh mounted on the top frame, a brush barrel mounted below the top frame, a small motor mounted in the brush barrel, and legs mounted at the four corners of the top frame. In order to remove light-density objects under the large filter mesh, the large filter mesh needs to be turned over regularly. The dirt attached to the large filter mesh is the object of cleaning. After the brush tube cleans the dirt from the large filter mesh, since the water flow direction in the raw water collection tank is from bottom to top, the cleaned dirt is carried to the small filter mesh by the water flow, and the small filter mesh blocks the dirt.

2. The industrial cleaning wastewater purification system according to claim 1, characterized in that: The qualified water treated by the phosphorus removal resin unit and the nitrogen removal resin unit enters the municipal pipeline network through the discharge trough.

3. The industrial cleaning wastewater purification system according to claim 1, characterized in that: The filtration and sterilization system includes a clean water tank connected to the membrane biological reaction unit, a sand / carbon filter connected to the clean water tank, a UV sterilization unit connected to the sand / carbon filter, and an RO unit connected to the UV sterilization unit. The RO unit is connected to a recycled water tank, and the recycled water tank is connected to a cooling tower.

4. An industrial cleaning wastewater purification system according to claim 3, characterized in that: The RO unit is connected to a concentrated water collection tank, and the wastewater enters the phosphorus removal resin unit and the nitrogen removal resin unit through the concentrated water collection tank. The resin regeneration waste liquid flowing out of the phosphorus removal resin unit and the nitrogen removal resin unit enters the waste liquid collection tank, and the wastewater in the waste liquid collection tank enters the low-temperature evaporator.

5. The industrial cleaning wastewater purification system according to claim 1, characterized in that: The sludge treatment system comprises a sludge relay tank connected to the membrane biological reaction unit and a filter press connected to the sludge relay tank.

Images