Low-concentration organic wastewater recovery treatment system

Abstract

The utility model relates to a low-concentration organic wastewater recovery treatment system which is provided with a pretreatment part, a biological activated carbon treatment part, a self-cleaning filter treatment part, an ultrafiltration treatment part and a reverse osmosis treatment part which are communicated through pipelines according to a treatment flow, wherein the pretreatment part is provided with an air flotation device, the biological activated carbon treatment part is internally provided with a ferrous iron doser, and the ultrafiltration treatment part is internally provided with a charge neutralizer doser; part of particulate matters in the wastewater are removed through the air flotation device, so that the pollution and blockage risk of subsequent equipment is reduced; through ferrous ions released in water, the activity of microorganisms in water and sufficient reaction of organic matters can be promoted, so that polar substances are passivated; the charge neutralizer is released in water, so that the adhesion of polar substances to the ultrafiltration membrane can be reduced, and the service life of the ultrafiltration membrane is prolonged.

Description

Technical Field

[0001] The utility model relates to a recovery and treatment system. In a recovery and treatment system for industrial low-concentration organic wastewater and effluent water in an electronics factory, a pretreatment air flotation device, a ferrous ion dosing device and a charge neutralizer dosing device are provided, so that the treated water quality is far superior to that of tap water and can be directly used as industrial process water. Background Art

[0002] With the increasingly scarce water resources, it is difficult to apply for industrial tap water, and the price is relatively high. Moreover, during the flood season, due to the rising turbidity of raw water, the quality of tap water is abnormal and water cut-offs occur frequently. Coupled with the increasing environmental awareness and other factors, the cost of obtaining industrial water for factories has increased.

[0003] For the recovery system of an electronics factory, in low-concentration organic wastewater and effluent water, in addition to suspended solid substances, pollutants such as heavy metals, hardness, and conductivity will affect the recovery efficiency. Organics, surfactants, and polar coagulants are even the greatest challenges for the ultrafiltration and reverse osmosis membrane treatment units in the system.

[0004] The existing recovery systems can be divided into two types: those without a biological treatment unit and those with a biological treatment unit. Among them, the system without a biological treatment unit often grows bacteria in the system due to the presence of organics in the raw water, resulting in the clogging of the ultrafiltration and reverse osmosis membranes in the recovery system due to biological contamination, or the irreversible chemical contamination of the ultrafiltration and reverse osmosis membranes by polar substances in the wastewater, leading to a significant increase in the consumable cost and a lower recovery efficiency than expected. Although the system with a biological treatment unit can treat the organics in the water, due to the low chemical oxygen demand (COD) in industrial low-concentration organic wastewater and effluent water, and the remaining organics in the water are mostly macromolecular chain organics discharged from the process, which are in a form difficult to biodegrade, it is very difficult to use biological activity to decompose the organics in the water, and it is very difficult to maintain the biological system, resulting in a still high risk of contamination of the subsequent ultrafiltration and reverse osmosis membrane units by organics and polar substances with uneven charge distribution.

[0005] Therefore, the utility model studies and improves the disadvantages of low-concentration organic recycled water treatment. Summary of the Utility Model

[0006] Therefore, the utility model aims to provide a low-concentration organic wastewater recovery and treatment system, which combines a pretreatment air flotation device, a ferrous ion dosing device and a charge neutralizer dosing device, so that the recovery system will not be affected by problems such as low efficiency of the biological unit, fouling and blockage of ultrafiltration and reverse osmosis membrane modules, and poor water quality of the produced water, and can provide stable and high-efficiency operation.

[0007] To achieve the above object, the utility model provides a low-concentration organic wastewater recovery and treatment system. Its main features are that it is successively provided with a pretreatment section, a biological activated carbon treatment section, a self-cleaning filter treatment section, an ultrafiltration treatment section, and a reverse osmosis treatment section that are connected by pipelines; among them,

[0008] The pretreatment section is used to provide residence for low-concentration organic wastewater and control the pH value of the water to reach pH 6-9. It successively includes an adjustment tank, a first water pump, a pH adjustment tank, a flotation device, and a flotation product tank that are connected by pipelines. The flotation device is used to remove suspended solids in the water;

[0009] The biological activated carbon treatment section successively includes a second water pump, a biological activated carbon processor, a biological activated carbon sedimentation tank, and a biological activated carbon product tank that are connected by pipelines. The second water pump is connected to the flotation product tank. An aeration device and biological sludge are arranged inside the biological activated carbon processor. Through the aeration device, the raw water and the biological sludge are fully mixed and contacted for reaction; the biological activated carbon sedimentation tank is connected to the biological activated carbon processor and is used to return the sludge in the biological activated carbon sedimentation tank to the biological activated carbon processor;

[0010] The self-cleaning filter treatment section successively includes a third water pump, a self-cleaning filter device, and a self-cleaning filter product tank that are connected by pipelines. The third water pump is connected to the biological activated carbon product tank;

[0011] The ultrafiltration treatment section successively includes a fourth water pump, an ultrafiltration device, and an ultrafiltration product tank that are connected by pipelines. A charge neutralizer dosing device is arranged between the fourth water pump and the ultrafiltration device and is used to release a charge neutralizer mainly composed of polyaluminum chloride in the water;

[0012] The reverse osmosis treatment section successively includes a fifth water pump, an ultraviolet germicidal lamp, a reverse osmosis pre-filter, a reverse osmosis treatment device, and a reverse osmosis product tank that are connected by pipelines. The fifth water pump is connected to the ultrafiltration product tank. The ultraviolet germicidal lamp is used to kill bacteria in the water; a filter element type filter with pores of 5um - 10um is arranged inside the reverse osmosis pre-filter; the reverse osmosis processor is provided with a semi-permeable membrane and is used to separate ionic impurities and pure water in the water;

[0013] The reverse osmosis product tank is respectively connected to a reverse osmosis concentrated water tank and a recycled water tank;

[0014] The system includes a sludge tank, and the sludge tank is respectively connected to the flotation device, the biological activated carbon sedimentation tank, and the ultrafiltration device.

[0015] Preferably, the pH adjustment tank is respectively connected to a hydrochloric acid dosing device and a sodium hydroxide dosing device.

[0016] Preferably, the biological activated carbon treatment part is respectively connected to a powdered activated carbon adder and a divalent iron adder. The powdered activated carbon adder is used to add powdered activated carbon; the divalent iron adder is used to release divalent iron ions in water so that the microbial activity and the organic matter decomposition ability in the sludge can be maintained at a relatively high level.

[0017] Preferably, a stainless steel screen is provided inside the self-cleaning filter device to screen out larger-sized solid substances and colloidal substances in water.

[0018] According to the low-concentration organic wastewater recovery and treatment system of the present utility model, a pretreatment part, a biological activated carbon treatment part, a self-cleaning filter treatment part, an ultrafiltration treatment part, and a reverse osmosis treatment part that are connected in sequence through pipelines according to the treatment process are provided. After the wastewater is treated through this series of processes, the quality of the produced water can reach the industrial process water level.

[0019] According to the low-concentration organic wastewater recovery and treatment system of the present utility model, a flotation device is provided in the pretreatment part to remove surfactants and most of the suspended substances in water, which can reduce the working load of the biological activated carbon treatment part, protect the subsequent ultrafiltration and reverse osmosis membrane systems, and reduce the risk of fouling.

[0020] According to the low-concentration organic wastewater recovery and treatment system of the present utility model, through a divalent iron dosing device and a charge neutralizer dosing device, divalent iron and a charge neutralizer are released in water, which can greatly reduce the interference and influence of pollutants such as organic matter, polar surfactants, and polar coagulants on the ultrafiltration and reverse osmosis membrane systems, extend the service life of various consumables, and enable the recovery system to operate continuously and more stably.

[0021] According to the low-concentration organic wastewater recovery and treatment system of the present utility model, the probability of the ultrafiltration and reverse osmosis membrane modules being contaminated and blocked is reduced, the service life of the ultrafiltration and reverse osmosis membranes is extended, and the operating cost of the recovery system can be greatly reduced. Description of the Drawings

[0022] Figure 1 It is a configuration schematic diagram of the low-concentration organic wastewater recovery and treatment system of the present utility model.

[0023] Reference Numerals

[0024] 11, 12, 13, 14, 15, 16 Water pumps

[0025] 100 Pretreatment part

[0026] 101 Regulation tank

[0027] 102 pH adjustment tank

[0028] 102A Hydrochloric Acid Dosing Device

[0029] 102B Sodium Hydroxide Dosing Device

[0030] 103 Flotation Device

[0031] 104 Flotation Product Water Tank

[0032] 105 Sludge Tank

[0033] 200 Biological Activated Carbon Treatment Section

[0034] 201 Biological Activated Carbon Processor

[0035] 201A Aeration Device

[0036] 201B Biological Sludge

[0037] 201C Powdered Activated Carbon Adding Device

[0038] 201D Ferrous Ion Dosing Device

[0039] 202 Biological Activated Carbon Sedimentation Tank

[0040] 203 Biological Activated Carbon Product Water Tank

[0041] 300 Self-Cleaning Filter Treatment Section

[0042] 301 Self-Cleaning Filter Device

[0043] 302 Self-Cleaning Filter Product Water Tank

[0044] 400 Ultrafiltration Treatment Section

[0045] 401 Ultrafiltration Device

[0046] 402 Ultrafiltration Product Water Tank

[0047] 403 Charge Neutralizer Dosing Device

[0048] 500 Reverse Osmosis Treatment Section

[0049] 501 Ultraviolet Germicidal Lamp

[0050] 502 Reverse Osmosis Prefilter

[0051] 503 Reverse Osmosis Treatment Device

[0052] 504 Reverse Osmosis Product Water Tank

[0053] 505 Reverse Osmosis Concentrate Water Tank

[0054] 600 Reclaimed Water Tank Detailed Implementation Manner

[0055] In order to make the technical means, creative features, achieved purposes and effects realized by the present utility model easy to understand, the present utility model will be further described below in conjunction with specific embodiments.

[0056] The low-concentration organic wastewater recovery and treatment system of the present utility model, as Figure 1 shown, is provided with a pretreatment unit 100, a biological activated carbon treatment unit 200, a self-cleaning filter treatment unit 300, an ultrafiltration treatment unit 400 and a reverse osmosis treatment unit 500 which are connected by pipelines according to the treatment process. Among them:

[0057] The pretreatment unit 100 is provided with an adjustment tank 101, a pH adjustment tank 102, a flotation device 103, a flotation product water tank 104 and a sludge tank 105. After the raw water of the industrial low-concentration organic wastewater to be treated is introduced into the adjustment tank 101 and stays to achieve uniform mixing, it is then pumped into the pH adjustment tank 102 by a water pump 11. In the pH adjustment tank 102, the pH value of the raw water can be adjusted through a hydrochloric acid dosing device 102A and a sodium hydroxide dosing device 102B, so that the quality of the raw water can meet the environment for biological growth (for example, pH is 6-9), and then it flows into the flotation device 103 by gravity. The suspended solids in the water are removed through flotation treatment. The water discharged from the flotation device enters the flotation product water tank 104 and is pumped into the biological activated carbon processor 201 of the biological activated carbon treatment unit 200 by a water pump 12. The sludge generated by flotation is discharged into the sludge tank 105.

[0058] The biological activated carbon treatment unit 200 is provided with a biological activated carbon processor 201, a biological activated carbon sedimentation tank 202 and a biological activated carbon product water tank 203. An aeration device 201A and biological sludge 201B are provided in the biological activated carbon processor 201. When the raw water enters, the aeration device 201A is started to fully mix and contact the biological sludge 201B and the raw water, and dissolve oxygen is provided for the microorganisms in the biological sludge to react; moreover, a powdered activated carbon feeder 201C is provided above the biological activated carbon processor 201, which can supply powdered activated carbon into the tank. The adsorbing force of the activated carbon is used to fix the organic matter in the treated raw water, and then the microorganisms in the biological sludge decompose the organic matter attached to the activated carbon, and then the activated carbon is restored. By using this reaction mechanism, the contact reaction time between the microorganisms and the organic matter can be extended, and the contact area between the microorganisms and the organic matter can be greatly increased through the pores densely distributed on the surface of the activated carbon, so as to obtain better product water quality.

[0059] A divalent iron dosing device 201D is also provided in the biological activated carbon processor 201. A divalent iron ion generator formed by sintering wood charcoal and iron is provided in the divalent iron dosing device 201D, which can release divalent iron ions in water, so that the microbial activity and the organic matter decomposition ability in the sludge can be maintained at a relatively high level, and the microorganisms will not reduce the decomposition efficiency due to the low concentration of chemical oxygen demand (COD) in the raw water.

[0060] After the water in the biological activated carbon processor 201 is decomposed by the biological sludge 201B and the organic matter is removed, it enters the biological activated carbon sedimentation tank 202 to settle the biological sludge in the water. The water production without biological sludge then enters the biological activated carbon water production tank 203, and is then pumped by the water pump 13 to the self-cleaning filter device 301 of the self-cleaning filter treatment section 300. The sludge in the biological activated carbon sedimentation tank 202 is refluxed to the biological activated carbon processor 201, and part of the surplus sludge is discharged to the sludge tank 105.

[0061] The self-cleaning filter treatment section 300 is provided with a self-cleaning filter processor 301 and a self-cleaning filter water production tank 302. A stainless steel screen is provided in the self-cleaning filter processor 301 to intercept the solid substances and colloidal substances in the water with particle sizes larger than the screen gap within the screen, so as to reduce the chance of fouling of the subsequent ultrafiltration and reverse osmosis membrane treatment units; the water production passing through the self-cleaning filter processor 301 enters the self-cleaning filter water production tank 302 and stays, and is then pumped by the water pump 14 to the ultrafiltration processor 401 of the ultrafiltration treatment section 400. When the self-cleaning filter accumulates a certain pressure difference, it will be cleaned to restore the operating pressure difference, and the sundries inside the screen are washed off by the internal automatic cleaning brush and discharged into the sludge tank 105.

[0062] The ultrafiltration treatment section 400 is provided with an ultrafiltration processor 401 and an ultrafiltration water production tank 402. A charge neutralizer dosing device 403 is provided in the pipeline connecting it to the self-cleaning filter treatment section 300. The charge neutralizer dosing device 403 can release a charge neutralizer mainly composed of polyaluminum chloride in the water, which can carry out an electro-neutralization effect with the particles in the water, reduce the pollution of the ultrafiltration and reverse osmosis membranes by polar substances and reduce the adhesion between the filter cake and the ultrafiltration and reverse osmosis membranes, reduce the chance of ultrafiltration fouling, and greatly improve the durability of ultrafiltration. The raw water containing the charge neutralizer in the water then enters the ultrafiltration processor 401.

[0063] An ultrafiltration membrane is provided in the ultrafiltration processor 401, which can be used to remove suspended particles, residual colloidal substances and macromolecular organic matter in the water, reduce the silt density index (SDI) in the water, and enable the subsequent reverse osmosis treatment section to operate with higher efficiency. After the water production is treated, it enters the ultrafiltration water production tank 402 and stays, and is then pumped by the water pump 15 to the ultraviolet germicidal lamp 501 of the reverse osmosis treatment section 500.

[0064] The reverse osmosis treatment unit 500 is provided with an ultraviolet germicidal lamp 501, a reverse osmosis pre-filter 502, a reverse osmosis processor 503, and a reverse osmosis product water tank 504. Among them, the ultraviolet germicidal lamp 501 is installed at the front end of the pipeline, so that the water is sterilized by the ultraviolet germicidal lamp 501 before flowing into the reverse osmosis pre-filter 502; the reverse osmosis pre-filter 502 is provided with a cartridge filter membrane with pores of 5 μm to 10 μm, and the reverse osmosis processor 503 is provided with a semi-permeable membrane to separate impurities at the ionic level in the water from pure water, so that dissolved solids, organic matters, etc. in the water are discharged from the concentrated drainage side of the reverse osmosis processor 503 to the reverse osmosis concentration tank 503 and used as cleaning water to improve the recovery rate of the entire recovery treatment unit.

[0065] After the produced water is treated by the reverse osmosis processor 503, it can reach the industrial process water level, that is, the industrial process water requirements with a conductivity of about 50 μs / cm or less, a suspended solid (SS) concentration of less than 1 ppm, a total organic carbon (TOC) of less than 1 ppm, a turbidity of less than 1 NTU, and a total hardness of less than 10 ppm in the water. After entering the reverse osmosis product water tank 504 for storage, it is then pumped to the recycled water tank 600 by the water pump 16.

[0066] Therefore, the beneficial effects of the low-concentration organic wastewater recovery treatment system of the present utility model are as follows:

[0067] 1. Reduce the loss of ultrafiltration membranes.

[0068] 2. Increase the service life of ultrafiltration membranes and reverse osmosis membranes, make the low-concentration organic wastewater recovery system feasible, and have recovery economic benefits.

[0069] 3. Under the conditions of the raw water conductivity of 3500 μs / cm, TOC of 20 ppm, total hardness of 200 ppm, and suspended solid concentration of 30 ppm, improve to meet the following standards: conductivity of about 50 μs / cm or less, suspended solid concentration of less than 1 ppm, TOC of less than 1 ppm, turbidity of less than 1 NTU, and total hardness of less than 10 ppm.

[0070] 4. Reduce the factory wastewater discharge and the consumption of tap water, so that the growth of the factory production line is not limited by the restrictions of the regulatory authorities on the consumption of tap water and the wastewater discharge.

[0071] In summary, the low-concentration organic wastewater recovery treatment system of the present utility model can indeed improve the recovery effect of low-concentration organic wastewater.

[0072] In this specification, the present utility model has been described with reference to its specific embodiments. However, it is obvious that various modifications and transformations can still be made without departing from the spirit and scope of the present utility model. Therefore, the specification and the drawings should be considered illustrative rather than restrictive.

Claims

1. A low-concentration organic wastewater recovery and treatment system, characterized in that, The pretreatment section, biological activated carbon treatment section, self-cleaning filter treatment section, ultrafiltration treatment section and reverse osmosis treatment section are sequentially provided with pipelines communicating with each other; The pretreatment unit is used to provide low-concentration organic wastewater with a retention period and control the pH value of the water to 6-9, and includes a regulating tank, a first water pump, a pH adjustment tank, an air flotation device, and an air flotation water production tank connected by pipelines. The air flotation device is used to remove suspended matter in the water; The biological activated carbon treatment unit includes, in sequence, a second water pump, a biological activated carbon processor, a biological activated carbon sedimentation tank, and a biological activated carbon water production tank, all of which are interconnected by pipelines. The second water pump is connected to the flotation water production tank. An aeration device and biological sludge are provided inside the biological activated carbon processor. The aeration device allows the raw water and biological sludge to be fully mixed and contacted for reaction. The biological activated carbon sedimentation tank is connected to the biological activated carbon processor to return the sludge in the biological activated carbon sedimentation tank to the biological activated carbon processor. The self-cleaning filter processing unit includes a third water pump, a self-cleaning filter device, and a self-cleaning filter water production pool connected by pipelines in sequence, and the third water pump is connected to the biological activated carbon water production pool; The ultrafiltration treatment unit includes a fourth water pump, an ultrafiltration device, and an ultrafiltration water production pool connected by pipelines. A charge neutralizer doser is provided between the fourth water pump and the ultrafiltration device for releasing a charge neutralizer with polyaluminum chloride as a main component into the water. The reverse osmosis treatment unit includes, in sequence, a fifth water pump, an ultraviolet germicidal lamp, a reverse osmosis pre-filter, a reverse osmosis processor, and a reverse osmosis water production pool, all of which are interconnected by pipelines. The fifth water pump is connected to the ultrafiltration water production pool, and the ultraviolet germicidal lamp is used to kill bacteria in the water. The reverse osmosis pre-filter is provided with a cartridge filter with a pore size of 5 to 10 μm. The reverse osmosis processor is provided with a semipermeable membrane for separating ionic impurities in the water from pure water. The reverse osmosis water production pool is connected to the reverse osmosis concentrated water pool and the recycled water pool respectively; The system comprises a sludge pool, which is respectively connected to the air flotation device, the biological activated carbon sedimentation tank and the ultrafiltration device.

2. The low-concentration organic wastewater recovery and treatment system according to claim 1, characterized in that The pH adjustment tank is connected to the hydrochloric acid dosing device and the sodium hydroxide dosing device respectively.

3. The low-concentration organic wastewater recovery and treatment system according to claim 1, wherein The biological activated carbon treatment part is connected to a powdered activated carbon adder and a divalent iron adder respectively. The powdered activated carbon adder is used to add powdered activated carbon; the divalent iron adder is used to release divalent iron ions in water so that the microbial activity and organic matter decomposition ability in the sludge can be maintained at a high state.

4. The low-concentration organic wastewater recovery and treatment system according to claim 1, characterized in that, The self-cleaning filter device is provided with a stainless steel screen inside, which is used to screen out solid matter and colloid matter with larger particle sizes in the water.

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