Vinyl imidazole wastewater pretreatment device

Abstract

The utility model relates to the technical field of wastewater pretreatment, in particular to a vinyl imidazole wastewater pretreatment device which comprises a pretreatment tank, a deoxidation tank, a reduction tank, an activation tank, a neutralization and flocculation tank and a precipitation tank are sequentially arranged in the pretreatment tank according to the flow direction of wastewater, a sponge iron layer is arranged in the deoxidation tank, and a reducing agent feeding port is formed in the reduction tank. And a titanium dioxide photocatalyst net and a lamp tube are arranged in the activation tank. According to the device, vinyl imidazole rings in the wastewater can be broken to form biodegradable organic matters such as carboxylic acid, so that the subsequent biochemical treatment difficulty and treatment cost are reduced, and compared with Fenton oxidation treatment, the device has the advantages that the degradation efficiency is higher, the economical efficiency is better, the secondary pollution is reduced and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater pretreatment, in particular to a vinyl imidazole wastewater pretreatment device. Background Art

[0002] Vinyl imidazole is a nitrogen-containing heterocyclic compound containing vinyl and imidazole groups. It has many applications and functions in industrial chemistry and can be used as a resin hardener, photosensitive agent, polymer modifier, etc. For example, vinyl imidazole is used as a ligand of a coordination compound to participate in a metal catalytic reaction, or as a monomer of a polymer to participate in a polymerization reaction to prepare a polymer material with special functions. A preparation method of vinyl imidazole is as follows: first, imidazole reacts with a catalyst potassium hydroxide at 80-120°C and normal pressure to generate an activated product C3H3KN2, and then imidazole reacts with acetylene in a C3H3KN2 activation solution, at a temperature of 120-150°C and a pressure of 0.2MPa to generate the product. However, vinyl imidazole will discharge high-concentration organic wastewater during the production process. The CODcr value of the wastewater is about 15000-20000 mg / L, and the total nitrogen concentration is about 4000-5000 mg / L. The wastewater also contains vinyl imidazole, which has a stable structure, biological toxicity, and is difficult to be decomposed by organisms. Therefore, pretreatment is required before the wastewater is biochemically treated.

[0003] At present, the main method of destroying the structure of vinyl imidazole by pretreatment is the Fenton oxidation method: first, adjust the pH value of the wastewater to 2-3 with hydrochloric acid (sulfuric acid), then add ferrous sulfate to maintain the concentration ratio of ferrous ions and its reactants at 1:10-50; add hydrogen peroxide to maintain the concentration ratio of COD and H202 at 1:1 for 2-5 hours; finally, add alkali to adjust the pH, and add PAM solution to settle the sludge. However, this method still has the following problems: 1. The Fenton oxidation method is corrosive to a certain extent, and a large amount of sludge scum will be generated during the reaction; 2. The treatment cost is high, and the cost of treating 1t of wastewater is about 50-100 yuan; 3. The reaction process has high requirements for reagent control and management; 4. The nitrogen atom of the CN bond of vinyl imidazole contains lone pairs of electrons that are not easily polarized, have low reaction activity, and are difficult to be decomposed by ring opening, so the destruction effect of the Fenton oxidation method is poor.

[0004] Based on this, the present application provides a new treatment device for pre-treating vinyl imidazole wastewater, which can break the vinyl imidazole ring in the wastewater to form easily biodegradable organic matter such as carboxylic acid, thereby reducing the difficulty and cost of subsequent biochemical treatment. Utility Model Content

[0005] The utility model provides a vinyl imidazole wastewater pretreatment device, which can break the vinyl imidazole ring in the wastewater to form carboxylic acid and other easily biodegradable organic matter, thus facilitating subsequent biochemical treatment.

[0006] This application provides the following technical solutions:

[0007] A vinyl imidazole wastewater pretreatment device comprises a pretreatment tank, wherein a deoxidation tank, a reduction tank, an activation tank, a neutralization flocculation tank and a sedimentation tank are sequentially arranged in the pretreatment tank according to the flow direction of the wastewater, a sponge iron layer is arranged in the deoxidation tank, a reducing agent dosing port is arranged on the reduction tank, and a titanium dioxide photocatalyst net and a lamp tube are arranged in the activation tank.

[0008] Technical principle: The wastewater first enters the deoxygenation tank, where it reacts with sponge iron to reduce the dissolved oxygen content in the wastewater, which helps to inhibit oxidation reactions in the subsequent wastewater treatment process; the wastewater that has been preliminarily treated in the deoxygenation tank enters the reduction tank, where a reducing agent, such as formic acid, is added to cause a reduction reaction in the oxidizing substances in the wastewater, converting them into reduced or lower oxidized state compounds; the deoxygenated and reduced wastewater enters the activation tank, where it flows through the photocatalyst net, where formic acid is activated to produce highly reducing anion free radicals, thereby reducing vinyl imidazole to open the ring and break the chain to form carboxylic acids and other easily biodegradable organic matter; finally, after neutralization treatment and precipitation separation, the wastewater enters the subsequent biochemical treatment stage.

[0009] Beneficial effects:

[0010] 1. Targeted and more efficient degradation: The pretreatment process of the present application is carried out step by step through three steps: deoxygenation, reduction and activation, which has higher selectivity and targeting for the target pollutant vinylimidazole; and through the reduction of ring opening and chain breaking to form easily biodegradable organic matter, the biological toxicity of wastewater can be effectively reduced, which is more conducive to the overall treatment effect of wastewater and the final compliance with discharge standards; compared with the Fenton oxidation method, it can also avoid the side reactions and harmful intermediates that may be caused by the strong non-selective oxidation of the Fenton reaction.

[0011] 2. Better economy: The present application uses sponge iron for deoxidation and formic acid as a reducing agent, which is a more economical and resource-efficient method, while the Fenton reaction usually consumes a large amount of hydrogen peroxide and iron salts, which are relatively expensive.

[0012] 3. Environmentally friendly, reducing the risk of secondary pollution: This application uses anion free radicals generated by photocatalyst net and formic acid to perform ring-opening and chain-breaking reduction during the activation stage. This process reduces the use of chemical agents and reduces the risk of secondary pollution; and compared with the Fenton oxidation method, it can reduce the problem of generating a large amount of sludge scum during the treatment process.

[0013] 4. Operating conditions and safety: Fenton oxidation usually requires acidic conditions and higher temperatures, and has high requirements for reagent control and management during the reaction process. The operating conditions of the pretreatment method of the present application are relatively mild, the operation management is simpler, and it is more conducive to equipment maintenance and safe operation.

[0014] Furthermore, a partition is arranged in the activation tank, which divides the activation tank into at least two compartments. At least two groups of titanium dioxide photocatalyst nets are arranged in each activation tank, and the lamp tube is arranged between the two groups of titanium dioxide photocatalyst nets.

[0015] Beneficial effects: The activation tank is divided into multiple parts by partitions, which is beneficial to increasing the reaction time of wastewater in the activation tank; by setting at least two groups of titanium dioxide photocatalyst nets in each activation tank, the treatment efficiency can be guaranteed, and the lamp tube is set between the two groups of titanium dioxide photocatalyst nets to provide light source for the two groups of titanium dioxide photocatalyst nets.

[0016] Furthermore, the lamp tube is arranged in the activation groove through a bracket, and at least two groups of brackets are arranged along the height direction of the activation groove. The brackets are provided with lamp tube fixing holes.

[0017] Beneficial effects: The lamp tube is fixed in a simple manner through the lamp tube fixing hole, and multiple sets of brackets can ensure the stability of the installation.

[0018] Furthermore, a supporting layer is provided in the deoxidation tank, a plurality of through holes are provided on the supporting layer, and sponge iron is filled in the supporting layer; the filling height of the sponge iron is 500-800 mm.

[0019] Beneficial effect: The supporting layer is used to load the sponge iron. Setting the height of the sponge iron to 500-800mm can both ensure processing efficiency and reduce costs.

[0020] Furthermore, the water inlet pipe of the deoxidation tank is higher than the sponge iron, and the water hole arranged between the deoxidation tank and the reduction tank is lower than the sponge iron.

[0021] Beneficial effect: the water inlet pipe is higher than the sponge iron, so that the wastewater flows from top to bottom through the sponge iron layer and then enters the reduction tank.

[0022] Furthermore, gas stirring tubes are provided at the bottom of the deoxidation tank, reduction tank and activation tank, each gas stirring tube is provided with a plurality of air holes, the air inlet end of the gas stirring tube is connected to an air inlet main pipe, and the air inlet main pipe is connected to an inert gas storage tank.

[0023] Beneficial effect: Inert gas is sprayed into wastewater using a gas stirring tube to form bubbles, which mixes and stirs the wastewater and improves reaction efficiency.

[0024] Furthermore, a pH meter interface and a liquid alkali interface are provided on the neutralization flocculation tank.

[0025] Beneficial effect: After the wastewater enters the neutralization flocculation tank, liquid alkali is added through the liquid alkali interface to adjust the pH value of the wastewater. A pH detector is set on the pH meter interface to display the pH value in real time.

[0026] Furthermore, a guide tube is vertically arranged in the sedimentation tank, and the outlet of the neutralization and flocculation tank is connected to the top of the guide tube through the guide tube; an inclined trough is arranged at the bottom of the guide tube, and an outlet pipe is arranged at the top of the sedimentation tank, and the outlet pipe is connected to the biochemical treatment system through a pipeline.

[0027] Beneficial effect: It is beneficial for wastewater to enter the sedimentation tank through the guide tube, and an inclined slot is opened at the bottom of the guide tube, which is beneficial for the sediment to slide to the bottom of the sedimentation tank through the inclined slot, and the clean water flows into the biochemical treatment system through the water collecting weir at the upper part of the sedimentation tank.

[0028] Furthermore, a gas collecting hood is arranged on the top of the pretreatment tank, and a waste gas interface is arranged on the gas collecting hood.

[0029] Beneficial effect: The gas collecting hood is used to collect exhaust gas and discharge it to the exhaust gas treatment station through the exhaust gas interface.

[0030] Furthermore, the bottoms of the deoxygenation tank, the reduction tank, the activation tank, the neutralization flocculation tank, and the sedimentation tank are all provided with vents.

[0031] Beneficial effect: The vent is provided to facilitate the emptying of wastewater in each treatment tank and to facilitate maintenance and treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 It is the front view of the pretreatment tank;

[0033] Figure 2 This is a top view of the pretreatment tank;

[0034] Figure 3 This is the internal structure plan of the pretreatment tank;

[0035] Figure 4 for Figure 3 Cross-section at AA in the middle;

[0036] Figure 5 This is a schematic diagram of the installation of the lamp;

[0037] Figure 6 Schematic diagram of the arrangement of the gas stirring tube. DETAILED DESCRIPTION

[0038] The following is further described in detail through specific implementation methods:

[0039] The marks in the drawings of the specification include: pretreatment tank 1, gas collecting hood 11, exhaust gas interface 12, deoxygenation tank 2, water inlet pipe 20, support plate 21, sponge iron 22, reduction tank 3, reducing agent dosing port 31, activation tank 4, titanium dioxide photocatalyst net 41, lamp tube 42, bracket 43, lamp tube fixing hole 431, neutralization flocculation tank 5, liquid alkali interface 51, pH meter interface 52, sedimentation tank 6, water outlet pipe 60, guide tube 61, guide tube 65, gas stirring tube 7, water hole 100, vent 101.

[0040] Example

[0041] like Figure 1-4 As shown, a vinyl imidazole wastewater pretreatment device comprises a pretreatment tank 1, in which a deoxygenation tank 2, a reduction tank 3, an activation tank 4, a neutralization flocculation tank 5, and a sedimentation tank 6 are sequentially arranged according to the flow direction of the wastewater. A water inlet pipe 20 is arranged on the upper part of the deoxygenation tank 2, and a water outlet pipe 60 is arranged on the upper part of the sedimentation tank 6. Water holes 100 are arranged on the tank walls between the deoxygenation tank 2 and the reduction tank 3, the reduction tank 3 and the activation tank 4, and the activation tank 4 and the neutralization flocculation tank 5. After the wastewater enters from the water inlet pipe 20 of the deoxygenation tank 2, it passes through the reduction tank 3, the activation tank 4, the neutralization flocculation tank 5, and the sedimentation tank 6 in sequence, and finally enters the subsequent biochemical treatment stage from the water outlet pipe 60 of the sedimentation tank 6.

[0042] like Figure 3-4 As shown, a sponge iron layer is provided in the deoxidation tank 2 for reacting with the dissolved oxygen in the wastewater, thereby reducing the dissolved oxygen content of the wastewater; specifically, a supporting layer is also provided in the deoxidation tank 2, and the supporting layer in this embodiment is a supporting plate 21, and the four sides of the supporting plate 21 can be fixed to the four inner walls of the deoxidation tank 2 by bolts, and a number of through holes are evenly opened on the supporting plate 21, and the aperture of the through hole is smaller than the diameter of the sponge iron 22, which is mainly used to allow wastewater to pass through; the sponge iron 22 is filled on the supporting layer, and the filling height of the sponge iron 22 is 500-800mm, and the preferred filling height in this embodiment is 600mm. More preferably, in this embodiment, the water inlet pipe 20 of the deoxidation tank 2 is higher than the sponge iron 22, and the water holes 100 provided on the tank walls of the deoxidation tank 2 and the reduction tank 3 are lower than the sponge iron 22. In this way, the wastewater can pass through the sponge iron layer from top to bottom, so that the wastewater can fully contact and react with the sponge iron 22 to improve the reaction efficiency, and then flow to the bottom of the deoxidation tank 2 through the through holes on the support plate 21, and then enter the reduction tank 3 through the water holes 100 for reduction reaction.

[0043] like Figure 3 As shown, the reduction tank 3 is provided with a reducing agent dosing port 31, through which the reducing agent is added. In this embodiment, formic acid is specifically added, and the pH value is controlled to be 2-3; formic acid, as an organic acid with strong reducing properties, can undergo a reduction reaction with the oxidizing substances in the wastewater, converting them into compounds in a reduced state or a lower oxidized state, which is more convenient for subsequent treatment.

[0044] like Figure 3-4 As shown, the activation tank 4 is provided with a titanium dioxide photocatalyst net 41 and a lamp 42. The wastewater after deoxidation and reduction enters the activation tank 4 and flows through the photocatalyst net. The formic acid is activated to produce anion free radicals with strong reducing properties, thereby reducing the vinyl imidazole to open the ring and break the chain to form carboxylic acid and other easily biodegradable organic substances. Specifically, a partition is also provided in the activation tank 4, and the partition divides the activation tank 4 into at least two compartments; Figure 4 As shown, in this embodiment, two groups of partitions are arranged to divide the activation tank 4 into three compartments. Two groups of titanium dioxide photocatalyst nets 41 are arranged in each compartment of the activation tank 4, and the titanium dioxide photocatalyst nets 41 are arranged vertically.

[0045] like Figure 3 As shown, the lamp tube 42 is arranged between two groups of titanium dioxide photocatalyst nets 41. Specifically, the lamp tube 42 is arranged in the activation tank 4 through a bracket 43. At least two groups of brackets 43 are arranged and arranged along the height direction of the activation tank 4. In this embodiment, two groups of brackets 43 are arranged, one above the other. Each bracket 43 is arranged horizontally and its left and right ends are fixed on the tank wall of the activation tank 4. A lamp tube fixing hole 431 is opened on the bracket 43. Specifically, as shown in FIG. Figure 5 As shown, the lamp tube fixing hole 431 on the lower bracket 43 is a blind hole, and the lamp tube fixing hole 431 on the upper bracket 43 is a through hole; a waterproof sleeve is provided on the outer cover of the lamp tube 42, and the lamp tube 42 is passed through and fixed on the lamp tube fixing holes 431 of the upper and lower brackets 43. The lamp tube 42 of this embodiment adopts an ultraviolet lamp tube 42.

[0046] like Figure 6 As shown, in this embodiment, a gas stirring tube 7 is provided at the bottom of the deoxidation tank 2, the reduction tank 3, and the activation tank 4, and each gas stirring tube 7 is provided with a plurality of air holes, and the air inlet end of the gas stirring tube 7 is connected to an air inlet main pipe, and the air inlet main pipe is connected to an inert gas storage tank (not shown in the figure); this embodiment has nitrogen introduced (in other embodiments other than this embodiment, other inert gases, such as helium or carbon dioxide gas, can also be introduced), and nitrogen is sprayed into the wastewater by using the gas stirring tube 7 to form bubbles, and the wastewater is mixed and stirred to improve the reaction efficiency; it should be noted that the gas stirring tube 7 in this embodiment is an existing aeration device, the difference is that the gas introduced is an inert gas, so the specific structure of the gas stirring tube 7 is not repeated.

[0047] like Figure 3As shown, the neutralization flocculation tank 5 is provided with a pH meter interface 52 and a liquid alkali interface 51. After the wastewater enters the neutralization flocculation tank 5, liquid alkali is added through the liquid alkali interface 51 to adjust the pH value of the wastewater. A pH detector is provided on the pH meter interface 52 to display the pH value in real time. A guide tube 61 is vertically provided in the sedimentation tank 6. The outlet of the neutralization flocculation tank 5 is connected to the top of the guide tube 61 through a guide tube 65. The bottom of the guide tube 61 is also provided with an inclined groove (not shown in the figure); it is beneficial for the wastewater to enter the sedimentation tank 6 through the guide tube 61 to be precipitated. An inclined groove is provided at the bottom of the guide tube 61, which is beneficial for the sediment to slide to the bottom of the sedimentation tank 6 through the inclined groove, and the clean water flows into the biochemical treatment system through the upper water collecting weir of the sedimentation tank 6.

[0048] like Figure 2 As shown, in this embodiment, a gas collecting hood 11 is further provided on the top of the pretreatment tank 1, specifically, two gas collecting hoods 11 are provided, and an exhaust gas interface 12 is provided on the gas collecting hood 11. The gas collecting hood 11 is used to collect the exhaust gas and discharge it to the exhaust gas treatment station through the exhaust gas interface 12; Figure 4 As shown, the bottoms of the deoxygenation tank 2, the reduction tank 3, the activation tank 4, the neutralization flocculation tank 5, and the sedimentation tank 6 are all provided with drain ports 101, which are provided to facilitate emptying of wastewater in each treatment tank and to facilitate maintenance and treatment.

[0049] Experimental example:

[0050] According to the wastewater pretreatment device provided by the present application, the applicant conducted an experimental verification at the Chongqing Chemical Wastewater Treatment and Pollution Control Engineering Technology Research Center. The experiment used vinyl imidazole industrial wastewater from the Chongqing Chemical Research Institute. After setting the formic acid dosage to 30 mg / L and catalyzing with a photocatalyst and irradiating with an 80w ultraviolet lamp for 150 minutes, the wastewater emulsified oil disappeared and the light transmittance of the water improved. The experimental results are shown in Table 1 below:

[0051] Table 1: Vinyl imidazole experimental results

[0052] Process section Removal rate COD(mg / L) BOD(mg / L) B / C Before reaction Water Intake 21500 2320 0.11 After the reaction Water Intake 18650 5960 0.32

[0053] The experimental results show that:

[0054] The wastewater pretreatment device and treatment method provided in the present application can remove a certain amount of COD from vinyl imidazole wastewater. The B / C of the wastewater can be improved by the pretreatment device, indicating that the structure of vinyl imidazole has been destroyed, thereby improving the biodegradability of the wastewater and laying the foundation for subsequent biochemical treatment.

[0055] The above is only an embodiment of the utility model. The utility model is not limited to the field involved in this implementation case. The common knowledge such as the known specific structure and characteristics in the scheme is not described in detail here. It should be pointed out that for those skilled in the art, several deformations and improvements can be made without departing from the structure of the utility model, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A vinyl imidazole wastewater pretreatment device, characterized in that: It comprises a pretreatment tank, in which a deoxidation tank, a reduction tank, an activation tank, a neutralization flocculation tank and a sedimentation tank are arranged in sequence according to the flow direction of the wastewater. The deoxidation tank is provided with a sponge iron layer, the reduction tank is provided with a reducing agent dosing port, and the activation tank is provided with a titanium dioxide photocatalyst net and a lamp tube.

2. A vinyl imidazole wastewater pretreatment device according to claim 1, characterized in that: The activation tank is also provided with a partition, which divides the activation tank into at least two compartments. Each compartment of the activation tank is provided with at least two groups of titanium dioxide photocatalyst nets, and the lamp tube is arranged between the two groups of titanium dioxide photocatalyst nets.

3. A vinyl imidazole wastewater pretreatment device according to claim 2, characterized in that: The lamp tube is arranged in the activation tank through a bracket. At least two groups of brackets are arranged along the height direction of the activation tank. The brackets are provided with lamp tube fixing holes.

4. A vinyl imidazole wastewater pretreatment device according to any one of claims 1 to 3, characterized in that: A supporting layer is also arranged in the deoxidation tank, and a plurality of through holes are arranged on the supporting layer. Sponge iron is filled in the supporting layer; the filling height of the sponge iron is 500-800mm.

5. A vinyl imidazole wastewater pretreatment device according to claim 4, characterized in that: The water inlet pipe of the deoxidation tank is higher than the sponge iron, and the water hole arranged between the deoxidation tank and the reduction tank is lower than the sponge iron.

6. A vinyl imidazole wastewater pretreatment device according to claim 5, characterized in that: The bottoms of the deoxidation tank, reduction tank and activation tank are all provided with gas stirring tubes, each of which is provided with a plurality of air holes, and the air inlet end of the gas stirring tube is connected to an air inlet main pipe, which is connected to an inert gas storage tank.

7. A vinyl imidazole wastewater pretreatment device according to claim 6, characterized in that: The neutralization and flocculation tank is provided with a pH meter interface and a liquid alkali interface.

8. A vinyl imidazole wastewater pretreatment device according to claim 7, characterized in that: A guide tube is vertically arranged in the sedimentation tank, and the water outlet of the neutralization and flocculation tank is connected with the top of the guide tube through the guide tube; an inclined trough is arranged at the bottom of the guide tube, and an outlet pipe is arranged at the top of the sedimentation tank, which is connected to the biochemical treatment system through a pipeline.

9. A vinyl imidazole wastewater pretreatment device according to claim 1, characterized in that: A gas collecting hood is arranged on the top of the pretreatment tank, and a waste gas interface is arranged on the gas collecting hood.

10. A vinyl imidazole wastewater pretreatment device according to claim 9, characterized in that: The bottoms of the deoxidation tank, the reduction tank, the activation tank, the neutralization and flocculation tank, and the sedimentation tank are all provided with vents.

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