High-chemical-oxygen-demand coating wastewater treatment device

Abstract

The utility model relates to the technical field of wastewater treatment, and discloses a high-chemical-oxygen-demand coating wastewater treatment device which comprises a pretreatment tank, a first pH measuring instrument, a screening filter, an electrolysis aeration tank, an electrolysis device, a circulating device and an aeration device. And the pretreatment tank is communicated with a feeding pipeline. The first pH measuring instrument is used for monitoring the pH value of the liquid in the pretreatment tank. A liquid inlet of the screening tank is communicated with a liquid outlet of the pretreatment tank. A liquid inlet of the electrolytic aeration tank is communicated with a liquid outlet of the screening tank, and a filter screen is arranged at the liquid outlet of the screening tank. And an electrolysis cavity is formed in the electrolysis device, and the electrolysis device is used for conducting electrolytic oxidation treatment on liquid flowing through the electrolysis cavity. The circulating device is used for driving liquid in the electrolytic aeration tank to enter the electrolytic cavity and circulate back to the electrolytic aeration tank. And the aeration device is used for pumping air into the liquid in the electrolytic aeration tank.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a device for treating paint wastewater with high chemical oxygen demand. Background Art

[0002] The composition of paint industry wastewater is complex, including defoamers, emulsifiers, preservatives, organic or inorganic dyes and coagulants, etc., which are difficult to biodegrade and have high organic concentrations. They also contain suspended solids, heavy metals and other pollutants. At present, common paint wastewater treatment methods mainly include physical and chemical methods and biological methods. However, due to the high concentration of wastewater, the BOD5 / COD (five-day biochemical oxygen demand / chemical oxygen demand) value is generally low, and the biodegradability is poor. In actual industrial design, a combination of physical and chemical pretreatment and biochemical treatment is often used to treat wastewater. This treatment method has a complex treatment process and low treatment efficiency, and it is difficult to meet the demand for the sharp increase in the amount of paint industry wastewater.

[0003] Therefore, there is an urgent need for a high chemical oxygen demand coating wastewater treatment device to solve the above problems. Utility Model Content

[0004] The utility model aims to provide a device for treating paint wastewater with high chemical oxygen demand, which has a simple treatment process and high treatment efficiency.

[0005] In order to achieve the above-mentioned purpose, the utility model provides a high chemical oxygen demand coating wastewater treatment device, comprising:

[0006] A pretreatment tank, connected to which is a feed pipeline for feeding flocculants and pH regulators;

[0007] A first pH measuring instrument, which is used to monitor the pH value of the liquid in the pretreatment tank;

[0008] A sieve filter tank, the liquid inlet of which is connected to the liquid outlet of the pretreatment tank;

[0009] An electrolytic aeration tank, whose liquid inlet is connected to the liquid outlet of the sieve filter tank, and a filter screen is provided at the liquid outlet of the sieve filter tank;

[0010] An electrolytic device, wherein an electrolytic chamber is provided therein, and the electrolytic device is used to perform electrolytic oxidation treatment on a liquid flowing through the electrolytic chamber;

[0011] A circulation device, which is used to drive the liquid in the electrolytic aeration tank into the electrolysis chamber and circulate back to the electrolytic aeration tank;

[0012] An aeration device is used to pump air into the liquid in the electrolytic aeration tank.

[0013] As an improvement of the above technical solution, it also includes a water inlet pool, and the liquid outlet of the water inlet pool is connected to the liquid inlet of the pretreatment pool.

[0014] As an improvement of the above technical solution, a plurality of feed pipelines are arranged on the pretreatment tank, including a first feed pipeline, a second feed pipeline and a third feed pipeline. The first feed pipeline is used for feeding a pH adjusting reagent, the second feed pipeline is used for feeding a first flocculant, and the third feed pipeline is used for feeding a second flocculant.

[0015] As an improvement of the above technical solution, it also includes a water outlet tank, and the liquid inlet of the water outlet tank is connected to the liquid outlet of the electrolytic aeration tank.

[0016] As an improvement of the above technical solution, it also includes a solid waste collection tank, the sediment discharge outlet of the screening tank is connected to the sediment inlet of the solid waste collection tank, and the sediment discharge outlet is arranged at the bottom of the screening tank.

[0017] As an improvement of the above technical solution, it also includes a first agitator, and the pretreatment tank is provided with the first agitator.

[0018] As an improvement of the above technical solution, a second agitator is further included, and the electrolytic aeration tank is provided with the second agitator.

[0019] As an improvement of the above technical solution, it also includes a second pH measuring instrument, and the second pH measuring instrument is arranged in the electrolytic aeration tank.

[0020] As an improvement of the above technical solution, a temperature sensor is further included, and the temperature sensor is arranged in the electrolytic aeration tank.

[0021] As an improvement of the above technical solution, the anode plate of the electrolysis device is a boron-doped diamond electrode.

[0022] Compared with the prior art, the utility model has the following beneficial effects:

[0023] In the high chemical oxygen demand paint wastewater treatment device of the utility model, wastewater is flocculated by adding a flocculant in a pretreatment tank, and the pH value is adjusted by adding a pH adjusting agent, and floating oil and suspended solids are removed by demulsification and coagulation, and the pH value adjustment process is monitored by a first pH measuring instrument. The liquid treated in the pretreatment tank flows into the sieve filter tank for sedimentation, and the precipitated liquid flows into the electrolytic aeration tank for electrolysis and aeration treatment after being filtered through a filter screen, and organic pigments and volatile small molecules in the liquid are further removed by electrolysis and aeration treatment. The high chemical oxygen demand paint wastewater treatment device of the utility model has a simple wastewater treatment process and high efficiency, and can deeply remove organic compounds, ammonia nitrogen, chroma and turbidity that are difficult to biodegrade in paint wastewater. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a structural schematic diagram of a high chemical oxygen demand paint wastewater treatment device provided in an embodiment of the utility model.

[0025] In the figure:

[0026] 11. pretreatment tank; 111. first feed pipeline; 112. second feed pipeline; 113. third feed pipeline;

[0027] 12. The first pH measuring instrument;

[0028] 13. Screen filter; 131. Filter screen; 132. Sediment discharge port;

[0029] 14. Electrolytic aeration tank; 141. Fourth feed pipeline;

[0030] 15. electrolysis device; 151. electrolysis chamber;

[0031] 16. Aeration device; 17. Water inlet tank; 18. Water outlet tank; 19. Solid waste collection tank; 20. First agitator; 21. Second agitator; 22. Control valve. DETAILED DESCRIPTION

[0032] The following is a further detailed description of the specific implementation of the present invention in conjunction with the accompanying drawings and examples. The following examples are used to illustrate the present invention, but are not intended to limit the scope of the present invention.

[0033] In the description of the present invention, unless otherwise clearly specified and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0034] In the present utility model, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0035] In the description of this embodiment, the terms "upper", "lower", "right" and other directions or positional relationships are based on the directions or positional relationships shown in the drawings, and are only for the convenience of description and simplified operation, rather than indicating or implying that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation of the present invention. In addition, the terms "first" and "second" are only used to distinguish in the description and have no special meaning.

[0036] like Figure 1As shown, this embodiment provides a high chemical oxygen demand paint wastewater treatment device, which is used to treat paint wastewater with a COD (chemical oxygen demand) of 200000-300000 mg / L, an ammonia nitrogen concentration of 10000-11000 mg / L, and a pH of 3-6. The high chemical oxygen demand paint wastewater treatment device includes a pretreatment tank 11, a first pH measuring instrument 12, a sieve filter 13, an electrolytic aeration tank 14, an electrolysis device 15, a circulation device and an aeration device 16. The pretreatment tank 11 is connected with a feed pipeline, which is used to feed flocculants and pH adjusters. The first pH measuring instrument 12 is used to monitor the pH value of the liquid in the pretreatment tank 11. The liquid inlet of the sieve filter 13 is connected to the liquid outlet of the pretreatment tank 11. The liquid inlet of the electrolytic aeration tank 14 is connected to the liquid outlet of the sieve filter 13. The liquid outlet of the sieve filter 13 is provided with a filter screen 131, and the filter screen 131 is provided with multiple layers. An electrolytic chamber 151 is provided in the electrolytic device 15, and the electrolytic device 15 is used to perform electrolytic oxidation treatment on the liquid flowing through the electrolytic chamber 151. The circulation device is used to drive the liquid in the electrolytic aeration tank 14 into the electrolytic chamber 151 and circulate it back to the electrolytic aeration tank 14. The aeration device 16 is used to pump air into the liquid in the electrolytic aeration tank 14.

[0037] The high chemical oxygen demand paint wastewater treatment device provided in this embodiment is used for flocculation treatment of wastewater by adding flocculants in the pretreatment tank 11, and pH adjustment is performed by adding pH adjustment reagents. Floating oil and suspended solids are removed by demulsification and coagulation. The pH adjustment process is monitored by the first pH measuring instrument 12. The liquid treated in the pretreatment tank 11 flows into the sieve filter tank 13 for precipitation. The precipitated liquid is filtered through the filter screen 131 and flows into the electrolytic aeration tank 14 for electrolysis and aeration treatment. Organic pigments and volatile small molecules in the liquid are further removed by electrolysis and aeration treatment. The high chemical oxygen demand paint wastewater treatment device provided in this embodiment has a simple wastewater treatment process and high efficiency, and can deeply remove organic compounds, ammonia nitrogen, chroma and turbidity that are difficult to biodegrade in paint wastewater. In addition, the overall structure of the device is relatively simple and low-cost.

[0038] Alternatively, if Figure 1 As shown, a plurality of feed pipelines are provided on the pretreatment tank 11, including a first feed pipeline 111, a second feed pipeline 112 and a third feed pipeline 113. The first feed pipeline 111 is used for feeding the pH adjusting agent, the second feed pipeline 112 is used for feeding the first flocculant, and the third feed pipeline 113 is used for feeding the second flocculant. In this embodiment, the first flocculant is aluminum sulfate, and the second flocculant is polyacrylamide. The pH adjusting agent includes sodium hydroxide and hydrochloric acid.

[0039] Alternatively, if Figure 1As shown, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment also includes an inlet pool 17, the liquid outlet of the inlet pool 17 is connected to the liquid inlet of the pretreatment pool 11, and the inlet pool 17 is used to store and recycle the paint wastewater to be treated.

[0040] Alternatively, if Figure 1 As shown, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment also includes a water outlet pool 18, the liquid inlet of the water outlet pool 18 is connected to the liquid outlet of the electrolytic aeration tank 14, and the water outlet pool 18 is used to store the treated paint wastewater.

[0041] Furthermore, the effluent pool 18 is provided with a detector for monitoring the effluent COD, pH, ammonia nitrogen and chromaticity. The treated paint wastewater entering the effluent pool 18 needs to be tested for COD, pH, chromaticity and ammonia nitrogen, and can only be discharged or reused after passing the test.

[0042] Alternatively, if Figure 1 As shown, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment also includes a solid waste collection tank 19, and the sediment discharge port 132 of the filter tank 13 is connected to the sediment inlet of the solid waste collection tank 19, and the sediment discharge port 132 is arranged at the bottom of the filter tank 13. The larger floccules and solid particles precipitated in the lower layer of the filter tank 13 will be discharged to the solid waste collection tank 19 through the sediment discharge port 132 for centralized collection.

[0043] Alternatively, if Figure 1 As shown, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment also includes a first agitator 20. The first agitator 20 is arranged in the pretreatment tank 11. The stirring of the first agitator 20 can make the pH adjusting agent, the first flocculant and the second flocculant and the paint wastewater be evenly mixed to accelerate the pretreatment process of the paint wastewater and ensure the pretreatment effect.

[0044] Alternatively, if Figure 1 As shown, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment also includes a second agitator 21. The second agitator 21 is arranged in the electrolytic aeration tank 14. Through the stirring of the second agitator 21, the paint wastewater in the electrolytic aeration tank 14 can be circulated into the electrolysis device 15 for electrolysis, thereby ensuring the electrolysis effect.

[0045] Optionally, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment further includes a second pH meter, and the second pH meter is provided in the electrolytic aeration tank 14. The second pH meter is used to monitor the pH value change of the paint wastewater during the electrolysis process, so as to timely add a pH adjusting reagent for adjustment, thereby ensuring that the pH value of the paint wastewater during the electrolysis process is maintained between 7 and 8.

[0046] Optionally, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment further includes a temperature sensor, and a temperature sensor is provided in the electrolytic aeration tank 14. The temperature of the paint wastewater during the electrolysis process is monitored by the temperature sensor to ensure that the temperature of the paint wastewater during the electrolysis process is maintained within the range of 30-80 degrees Celsius, thereby preventing the paint wastewater from boiling due to the temperature process.

[0047] Furthermore, an electrolyte addition port is provided on the electrolytic aeration tank 14 for adding electrolyte into the electrolytic aeration tank 14. By adding electrolyte, the coating wastewater has good conductivity, which facilitates electrolysis. In this embodiment, the electrolyte is sodium chloride.

[0048] Furthermore, if Figure 1 As shown, the electrolytic aeration tank 14 is connected with a fourth feed pipeline, and the fourth feed pipeline is used to feed the pH adjusting agent and water. During the electrolysis process, the pH value of the coating wastewater in the electrolytic aeration tank 14 is adjusted by adding the pH adjusting agent, and the temperature of the coating wastewater in the electrolytic aeration tank 14 is adjusted by adding water. In addition, by adding water, the OH radical ions consumed by the coating wastewater during the electrolysis process can be supplemented to ensure the smooth progress of the electrolysis process.

[0049] Optionally, the anode plate of the electrolysis device 15 in this embodiment is a boron-doped diamond (BDD) electrode. The electrolysis device 15 in this embodiment is a BDD advanced oxidation module. Further, the cathode plate of the electrolysis device 15 in this embodiment is a titanium plate or a stainless steel plate.

[0050] Optionally, the high chemical oxygen demand paint wastewater treatment device provided in this embodiment also includes a control valve 22, and a control valve 22 is provided on the connecting pipelines between the water inlet tank 17 and the pretreatment tank 11, between the pretreatment tank 11 and the screen filter 13, between the screen filter 13 and the electrolytic aeration tank 14, between the screen filter 13 and the solid waste collection tank 19, and between the electrolytic aeration tank 14 and the water outlet tank 18.

[0051] The working process of the high chemical oxygen demand coating wastewater treatment device of this embodiment is as follows:

[0052] S1. Flocculation and sedimentation process: The recovered paint wastewater to be treated stored in the water inlet tank 17 is pumped into the pretreatment tank 11 through an electric pump; the first flocculant, the second flocculant and the pH adjusting agent are added to the paint wastewater to be treated in batches in the pretreatment tank 11. Specifically, after the paint wastewater enters the pretreatment tank 11, sodium hydroxide is added according to the volume of the paint wastewater to adjust the pH range to 9-11; after the pH stabilizes, the first flocculant is added according to the volume of the paint wastewater, and the pH range is 4-6; after the pH stabilizes again, sodium hydroxide is added again according to the volume of the paint wastewater (1-5g of sodium hydroxide is added per liter of paint wastewater) to adjust the pH range to 7-9; finally, the second flocculant is added according to the volume of the paint wastewater, and the mixture is left to stand and wait for flocculation to occur.

[0053] After sufficient flocculation, the obtained treated liquid is pumped into the filter tank 13 through an electric pump, and the flocculated materials and residual solid particles are removed through the filter screen 131 and the sediment discharge port 132.

[0054] S2, electrochemical treatment process: The solution obtained in step S1 is pumped into the electrolytic aeration tank 14 through an electric pump, and an electrolyte is added to the electrolytic aeration tank 14 until the electrolyte is fully dissolved. The paint wastewater in the electrolytic aeration tank 14 is electrolytically treated by the circulation device and the electrolytic device 15. During the treatment process, the pH of the paint wastewater is controlled between 7-8, the current density is greater than 35mA / cm2, the reaction temperature is controlled within the range of 30-80 degrees Celsius, and the treatment time is controlled within 5-250h. An aeration device 16 is installed at the bottom of the electrolytic aeration tank 14, and the aeration device 16 is used to remove the suspended matter remaining in the pre-treated paint wastewater after filtration, and simultaneously remove the irritating volatile substances present in the paint wastewater. It can be understood by those skilled in the art that the suspended matter remaining in the paint wastewater removed by the aeration device 16 will gather at the top layer of the paint wastewater, and the suspended matter generated by the aeration process can be removed by artificial removal.

[0055] S3. Storage of treated liquid: The liquid treated in the electrolytic aeration tank 14 is pumped into the outlet tank 18 by an electric pump and temporarily stored in the outlet tank 18. After being tested and qualified by a detector, it can be discharged and reused.

[0056] The high chemical oxygen demand paint wastewater treatment device of this embodiment achieves deep removal of small molecular organic matter, wastewater chromaticity and volatile irritating substances in paint wastewater through flocculation, screening, pretreatment to adjust pH, BDD electrode electrochemical catalysis and aeration by the aeration device 16, effectively reducing the harm of paint wastewater to the environment. In addition, the overall structure of the treatment device is relatively simple, the price of the reagents involved is not high, the operation and maintenance costs are low, and the cost is low. The chemical oxygen demand treatment range is wide, and a chemical oxygen demand removal rate of more than 99.97% is provided for high chemical oxygen demand paint wastewater (COD>200000mg / L), providing a practical and reliable method for the treatment of paint wastewater.

[0057] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and substitutions can be made without departing from the technical principle of the present invention. These improvements and substitutions should also be regarded as the protection scope of the present invention.

Claims

1. A high chemical oxygen demand coating wastewater treatment device, characterized in that: include: A pretreatment tank (11) is connected to a feed pipeline, wherein the feed pipeline is used for feeding a flocculant and a pH regulator; A first pH measuring instrument (12), which is used to monitor the pH value of the liquid in the pretreatment tank (11); A sieve filter tank (13), the liquid inlet of which is connected to the liquid outlet of the pretreatment tank (11); An electrolytic aeration tank (14), whose liquid inlet is connected to the liquid outlet of the sieve filter tank (13), and a filter screen (131) is provided at the liquid outlet of the sieve filter tank (13); An electrolysis device (15) having an electrolysis chamber (151) disposed therein, the electrolysis device (15) being used to perform electrolytic oxidation treatment on a liquid flowing through the electrolysis chamber (151); A circulation device, which is used to drive the liquid in the electrolytic aeration tank (14) into the electrolysis chamber (151) and circulate back to the electrolytic aeration tank (14); An aeration device (16) is used to pump air into the liquid in the electrolytic aeration tank (14).

2. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: The pretreatment tank (11) is provided with a plurality of feed pipelines, the plurality of feed pipelines comprising a first feed pipeline (111), a second feed pipeline (112) and a third feed pipeline (113), the first feed pipeline (111) being used for feeding a pH adjusting agent, the second feed pipeline (112) being used for feeding a first flocculant, and the third feed pipeline (113) being used for feeding a second flocculant.

3. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also comprises a water inlet pool (17), the liquid outlet of the water inlet pool (17) being in communication with the liquid inlet of the pretreatment pool (11).

4. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also comprises a water outlet tank (18), the liquid inlet of the water outlet tank (18) being in communication with the liquid outlet of the electrolytic aeration tank (14).

5. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also includes a solid waste collection tank (19), the sediment discharge outlet (132) of the sieve filter tank (13) is connected to the sediment inlet of the solid waste collection tank (19), and the sediment discharge outlet (132) is arranged at the bottom of the sieve filter tank (13).

6. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also comprises a first agitator (20), and the first agitator (20) is arranged in the pretreatment tank (11).

7. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also includes a second agitator (21), and the second agitator (21) is arranged in the electrolytic aeration tank (14).

8. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also includes a second pH measuring instrument, which is arranged in the electrolytic aeration tank (14).

9. The high chemical oxygen demand coating wastewater treatment device according to claim 1, characterized in that: It also comprises a temperature sensor, and the temperature sensor is arranged in the electrolytic aeration tank (14).

10. The high chemical oxygen demand coating wastewater treatment device according to any one of claims 1 to 9, characterized in that: The anode plate of the electrolysis device (15) is a boron-doped diamond electrode.

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