A device for pretreating alkali residue wastewater

Abstract

The application relates to the technical field of wastewater treatment, in particular to an alkali residue wastewater pretreatment device, which comprises a box body with a cavity, a first partition plate and a second partition plate are arranged in the box body, the first partition plate and the second partition plate divide the cavity in the box body into an electrolysis area, a precipitation area and an oxidation area; an electrolysis unit is used for generating ferrous ions in the alkali residue wastewater and oxidizing part of organic matters in the alkali residue wastewater; a precipitation unit is used for generating iron hydroxide flocculation in the alkali residue wastewater passing through the electrolysis area and adsorbing the organic matters in the alkali residue wastewater by the iron hydroxide flocculation; and an oxidation unit is used for degrading the residual organic matters in the alkali residue wastewater passing through the precipitation area; through the triple action of the electrolysis unit, the precipitation unit and the oxidation unit, the treatment of the organic matters in the alkali residue wastewater is realized, the pH value of the wastewater can be reduced to 8-9, and the COD value is also greatly reduced.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a pretreatment device for alkaline residue wastewater. Background Technology

[0002] Alkali washing is a common method used in oil refining to purify fuel oil. Because alkali solutions react with compounds containing sulfur, nitrogen, and oxygen in the oil, they effectively remove substances that affect oil stability and some sulfur-containing compounds, such as naphthenic acids, phenols, hydrogen sulfide, and mercaptans. Therefore, alkaline washing refining is a crucial step in improving oil properties and quality, but it also generates a large amount of alkaline wastewater. This wastewater contains numerous pollutants, with COD typically reaching thousands or even hundreds of thousands of mg / L. It also contains high levels of salt, primarily alkaline substances like sodium hydroxide and calcium hydroxide, making it difficult to treat using activated sludge processes. The treatment of high-salt, high-concentration, and recalcitrant alkaline wastewater remains a significant challenge for the petrochemical industry. Furthermore, direct discharge into the environment poses serious harm to the environment and human health. Therefore, the rational and effective treatment of alkaline wastewater is essential.

[0003] There are many ways to treat alkaline residue wastewater, including biological, chemical, and physical methods.

[0004] Biological methods refer to the use of microorganisms to degrade organic matter in wastewater, thereby improving and reducing the amount of organic matter. The most typical method is the activated sludge process. Because alkaline sludge wastewater is highly corrosive and alkaline, it can negatively impact the growth and activity of microorganisms, resulting in less than ideal degradation effects. Therefore, biological methods for treating alkaline sludge wastewater require strict control over conditions such as pH and temperature. pH control, in particular, necessitates a complex pretreatment process involving the addition of large amounts of acid.

[0005] Chemical methods refer to the use of chemical processes to treat harmful substances in wastewater through precipitation, adsorption, and neutralization. These methods mainly include neutralization precipitation and oxidation. Neutralization precipitation involves reacting alkaline and acidic substances in alkaline wastewater to produce relatively stable neutral salts, and then adsorbing and filtering the resulting precipitate. Through neutralization precipitation, alkaline and acidic substances in the wastewater are neutralized, thereby purifying the water. The advantages of using neutralization precipitation to treat alkaline wastewater are its simple operation and good treatment effect. However, neutralization precipitation also has limitations, namely high treatment costs and the need for further treatment of the precipitate, thus requiring significant investment in operation and maintenance.

[0006] Physical methods refer to the use of physical means to separate, filter, and distill harmful substances in wastewater, with adsorption and membrane separation being the most common. Adsorption involves using adsorbents to adsorb and concentrate harmful substances in wastewater. In the treatment of alkaline sludge wastewater, commonly used adsorbents include activated carbon, resin, and iron oxide. Adsorption methods can reduce COD and BOD levels to a certain extent and have a wide range of applications; however, the treatment effect is greatly affected by factors such as the type and concentration of substances in the wastewater and temperature. Membrane separation uses membrane technology to retain and separate organic matter and inorganic salts from wastewater, including nanofiltration, ultrafiltration, and reverse osmosis. Membrane separation can effectively separate organic matter, particulate matter, and ions from wastewater, offering advantages such as good treatment effect and low operating cost. However, it also has problems such as membrane clogging and fouling. Summary of the Invention

[0007] The technical problem this invention aims to solve is: In existing technologies, alkaline sludge wastewater contains a large amount of pollutants, with COD typically reaching several thousand mg / L or even hundreds of thousands of mg / L. Furthermore, the wastewater also contains high levels of salt, primarily alkaline substances such as sodium hydroxide and calcium hydroxide, making it difficult to treat using the activated sludge process. The treatment of high-salt, high-concentration, and recalcitrant alkaline sludge wastewater remains a challenging problem in the petrochemical industry. This invention provides an alkaline sludge wastewater pretreatment device.

[0008] The technical solution adopted by this invention to solve its technical problem is: a pretreatment device for alkaline residue wastewater, comprising:

[0009] The tank has a cavity, and a first partition and a second partition are arranged inside the tank. The first partition and the second partition divide the cavity inside the tank into an electrolysis zone, a precipitation zone and an oxidation zone. The first partition is located between the electrolysis zone and the precipitation zone, and the second partition is located between the precipitation zone and the oxidation zone. A water inlet is opened on the tank and is connected to the electrolysis zone. The water inlet is used to supply alkaline residue wastewater. A drain outlet is opened at the bottom of the tank and is connected to the oxidation zone.

[0010] The electrolysis unit is used to generate ferrous ions in the alkaline residue wastewater and oxidize some of the organic matter in the alkaline residue wastewater. The electrolysis unit is located in the electrolysis zone.

[0011] The sedimentation unit is used to generate ferric hydroxide flocs from the alkaline residue wastewater after passing through the electrolysis zone and to adsorb organic matter in the alkaline residue wastewater using the ferric hydroxide flocs. The sedimentation unit is located in the sedimentation zone, and an overflow port is provided at the upper part of the second partition plate. The overflow port is used to allow the upper clear liquid in the sedimentation zone to flow into the oxidation zone.

[0012] The system also includes an oxidation unit, which is used to degrade the organic matter remaining in the alkaline slag wastewater after passing through the sedimentation zone. The oxidation unit is located in the oxidation zone and, through the triple action of the electrolysis unit, sedimentation unit, and oxidation unit, it treats the organic matter in the alkaline slag wastewater, reducing the pH value of the wastewater to 8-9 and significantly lowering the COD value, allowing it to proceed to the next step of treatment.

[0013] The device further includes an electrolysis unit comprising electrodes and an iron raw material. The electrodes are installed in the electrolysis zone and are fixedly connected to the housing. The iron raw material is used to provide ferrous ions to the alkaline slag wastewater. The iron raw material is located in the electrolysis zone and is iron shavings.

[0014] The electrolysis unit further includes baffles, with each baffle corresponding to an electrode. The baffles are arranged in the electrolysis zone and connected to the housing. A V-shaped groove is formed between the baffle and its corresponding electrode, which is used to accommodate iron raw materials.

[0015] The settling unit further includes a coil, an air pipe, a submersible pump, and an ultraviolet lamp. The input end of the coil extends through the first partition into the electrolysis zone. The output end of the coil is located above the settling zone and above the input end of the coil. The submersible pump is installed on the coil and is used to provide power for the flow of alkaline wastewater. The input end of the air pipe extends to the outside of the tank and the output end of the air pipe is connected to the coil.

[0016] The ultraviolet lamp tube is fixedly connected to the cabinet, and the coil surrounds the ultraviolet lamp tube.

[0017] The sedimentation unit includes a venturi tube, and the submersible pump and coil are connected via the venturi tube. The inlet of the air pipe is connected to the venturi tube.

[0018] The oxidation unit further includes a packing material and an ozone aerator. The packing material is filled in the oxidation zone and is located between the overflow port and the drain port. The ozone aerator is fixedly connected to the housing and is located below the packing material. The packing material is activated carbon.

[0019] Further, the tank body is provided with a drain outlet, which is connected to the sedimentation zone and is located below the sedimentation zone.

[0020] Further, the chamber has an exhaust port located on the top surface of the chamber, and the exhaust port is connected to the sedimentation area.

[0021] The beneficial effects of the present invention are: the present invention provides an alkaline residue wastewater pretreatment device;

[0022] (1) Obtaining ferrous ions (Fe) by electrolysis 2 +), Fe 2 + Catalysis oxidizes some organic matter;

[0023] (2) In the precipitation zone, after oxygen is drawn in by the venturi tube, it affects Fe. 2 + undergoes oxidation to form Fe 3 The Fe(OH)3 flocs combine with the abundant OH- present in the wastewater to form flocs. During the formation of Fe(OH)3 flocs, a large amount of organic matter can be adsorbed and separated during the precipitation process. At the same time, due to the precipitation of OH-, the pH value can tend to be neutral, resulting in a better treatment effect.

[0024] (3) The precipitation unit utilizes the residual ferrous ions in the wastewater and the effect of ultraviolet light to further catalyze the oxidation of organic matter in the wastewater, while converting ferrous ions into ferric ions and ferric hydroxide precipitates.

[0025] (4) The oxidation unit utilizes the oxidation effect of ozone and the catalytic effect of the packing material to completely oxidize and remove the residual ferrous ions in the wastewater, avoiding secondary pollution, and can also degrade organic matter. Attached Figure Description

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 This is the present invention. Figure 1 A magnified structural diagram of point A in the middle.

[0029] In the diagram: 1. Box body, 11. First partition, 12. Second partition, 121. Overflow port, 13. Water inlet, 14. Drain, 15. Sewage outlet, 16. Exhaust port, 2. Electrolysis zone, 21. Electrolysis unit, 211. Electrode, 212. Iron raw material, 213. Baffle, 214. V-shaped groove, 3. Sedimentation zone, 31. Sedimentation unit, 311. Coil, 312. Air pipe, 313. Submersible pump, 314. Ultraviolet lamp, 315. Venturi tube, 4. Oxidation zone, 41. Oxidation unit, 411. Packing material, 412. Ozone aerator. Detailed Implementation

[0030] The present invention will now be described in further detail with reference to the accompanying drawings. These drawings are simplified schematic diagrams, illustrating only the basic structure of the invention, and therefore only show the components relevant to the invention.

[0031] like Figure 1 This is a schematic diagram of the structure of the present invention, a pretreatment device for alkaline residue wastewater, comprising:

[0032] The box 1 has a cavity. A first partition 11 and a second partition 12 are arranged inside the box 1. The first partition 11 and the second partition 12 divide the cavity inside the box 1 into an electrolysis zone 2, a precipitation zone 3 and an oxidation zone 4. The first partition 11 is located between the electrolysis zone 2 and the precipitation zone 3, and the second partition 12 is located between the precipitation zone 3 and the oxidation zone 4. A water inlet 13 is opened on the box 1 and is connected to the electrolysis zone 2. The water inlet 13 is used to supply alkaline residue wastewater. A drain outlet 14 is opened at the bottom of the box 1 and is connected to the oxidation zone 4.

[0033] Electrolysis unit 21 is used to generate ferrous ions in alkaline residue wastewater and oxidize a portion of the organic matter in alkaline residue wastewater. Electrolysis unit 21 is located in electrolysis zone 2.

[0034] Electrolysis unit 21 includes electrodes 211 and iron raw material 212. Electrode 211 is installed in electrolysis zone 2 and is fixedly connected to housing 1. Iron raw material 212 is used to provide ferrous ions to alkaline residue wastewater. Iron raw material 212 is located in electrolysis zone 2 and is made of iron shavings. Ferrous ions (Fe2+) are obtained by electrolysis. 2 +), Fe 2 The catalytic effect of + oxidizes some organic matter. During electrolysis, electrode 211 is connected to an external power source, which provides energy to electrode 211.

[0035] The electrolysis unit 21 also includes a baffle 213, which corresponds one-to-one with the electrode 211. The baffle 213 is arranged in the electrolysis zone 2 and is connected to the housing 1. The baffle 213 and its corresponding electrode 211 form a V-shaped groove 214. The V-shaped groove 214 is used to accommodate the iron raw material 212. The V-shaped groove 214 can allow the iron shavings to naturally move down and automatically stick to the electrode after being consumed. If it is not V-shaped, the iron shavings below may be consumed and create a gap with the electrode, resulting in an open circuit.

[0036] The sedimentation unit 31 is used to generate ferric hydroxide flocs from the alkaline residue wastewater passing through the electrolysis zone 2 and to adsorb organic matter in the alkaline residue wastewater using the ferric hydroxide flocs. The sedimentation unit 31 is located in the sedimentation zone 3. An overflow port 121 is provided on the upper part of the second partition 12. The overflow port 121 is used to allow the upper clear liquid in the sedimentation zone 3 to flow into the oxidation zone 4.

[0037] The sedimentation unit 31 includes a coil 311, an air pipe 312, a submersible pump 313, and an ultraviolet lamp 314. The input end of the coil 311 extends through the first partition 11 into the electrolysis zone 2. The output end of the coil 311 is located at the upper part of the sedimentation zone 3 and above the input end of the coil 311. The submersible pump 313 is installed on the coil 311 and is used to provide power for the flow of alkaline residue wastewater. The input end of the air pipe 312 extends to the outside of the housing 1, and the output end of the air pipe 312 is connected to the coil 311.

[0038] The ultraviolet lamp tube 314 is fixedly connected to the housing 1. The coil tube 311 surrounds the ultraviolet lamp tube 314. Utilizing the residual ferrous ions in the wastewater and the effect of ultraviolet light, the organic matter in the wastewater can be further catalyzed and oxidized. At the same time, the ferrous ions are converted into ferric ions and ferric hydroxide precipitates. The coil tube 311 is made of transparent material, usually quartz glass, so that the ultraviolet lamp tube 314 can irradiate into the coil tube 311. The coil tube 311 can restrict the airflow inside the tube, prolonging the reaction time of air oxidation inside the tube.

[0039] Precipitation unit 31 includes a venturi tube 315, a submersible pump 313 and a coil 311 connected via the venturi tube 315, and an air pipe 312 connected to the inlet of the air pipe 312. The venturi tube 315 has a constricted throat. After oxygen is drawn in by the venturi tube 315, it reacts with Fe. 2 + undergoes oxidation to form Fe 3 The Fe(OH)3 flocs combine with the abundant OH- in the wastewater to form flocs. During the formation of Fe(OH)3 flocs, a large amount of organic matter can be adsorbed and separated during the precipitation process. At the same time, due to the precipitation of OH-, the pH value can tend to be neutral, resulting in a better treatment effect. The Venturi tube 315 is designed to draw in oxygen, allowing the oxygen to be evenly distributed inside the tube.

[0040] The housing 1 is provided with a drain outlet 15, which is connected to the sedimentation zone 3 and is located below the sedimentation zone 3. The drain outlet 15 is used to discharge the sediment in the sedimentation zone 3. The housing 1 is provided with an exhaust outlet 16, which is located on the top surface of the housing 1 and is connected to the sedimentation zone 3. The exhaust outlet 16 is used to discharge the waste gas generated during the reaction process.

[0041] And oxidation unit 41, which is used to degrade the organic matter remaining in the alkaline residue wastewater after passing through the sedimentation zone 3, and oxidation unit 41 is located in oxidation zone 4.

[0042] Oxidation unit 41 includes packing material 411 and ozone aerator 412. Packing material 411 is filled within oxidation zone 4 and located between overflow port 121 and drain port 14. Ozone aerator 412 is fixedly connected to housing 1 and located below packing material 411. Packing material 411 is activated carbon or activated carbon or ceramic packing loaded with transition metal oxides. Utilizing the oxidizing effect of ozone and the catalytic effect of packing material 411, residual ferrous ions in the wastewater are completely oxidized and removed, preventing secondary pollution. It also degrades organic matter. In use, ozone aerator 412 is connected to ozone storage tank via an air pump.

[0043] During the treatment process, the alkaline wastewater enters the electrolysis zone 2 through inlet 13. Utilizing the high pH of the alkaline wastewater, electrolysis is used to dissolve iron shavings into ferrous ions. The alkaline wastewater containing ferrous ions enters the coil 311 and is then oxidized by air in the coil 311 to form flocculent ferric hydroxide precipitate. The ferric hydroxide precipitate can not only combine with hydroxide ions in the wastewater but also adsorb organic matter, thereby lowering the pH value at a very low cost. Furthermore, the residual ferrous ions in the wastewater and the action of ultraviolet light can further catalyze the oxidation of organic matter in the wastewater, while simultaneously converting ferrous ions into ferric ions and ferric hydroxide precipitate. The alkaline wastewater after secondary treatment enters the sedimentation zone 3 for sedimentation, where solid impurities are deposited at the bottom. The clear liquid on the top layer enters the oxidation zone 4 through overflow outlet 121. When passing through the packing 411, the residual ferrous ions in the wastewater are completely oxidized and removed by the oxidation effect of ozone and the catalytic effect of the packing, avoiding secondary pollution. Finally, it is discharged from the drain outlet 14.

[0044] Through the treatment of this pretreatment device, the pH value of the wastewater can be reduced to 8-9, and the COD value is also greatly reduced, allowing it to proceed to the next step of treatment.

[0045] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. A pretreatment device for alkaline residue wastewater, characterized in that, include: The box (1) has a cavity. A first partition (11) and a second partition (12) are arranged inside the box (1). The first partition (11) and the second partition (12) divide the cavity inside the box (1) into an electrolysis zone (2), a precipitation zone (3) and an oxidation zone (4). The first partition (11) is located between the electrolysis zone (2) and the precipitation zone (3). The second partition (12) is located between the precipitation zone (3) and the oxidation zone (4). A water inlet (13) is provided on the box (1). The water inlet (13) is connected to the electrolysis zone (2). The water inlet (13) is used to supply alkaline wastewater. A drain outlet (14) is provided at the bottom of the box (1). The drain outlet (14) is connected to the oxidation zone (4). An electrolysis unit (21) is used to generate ferrous ions in alkaline slag wastewater and oxidize a portion of the organic matter in the alkaline slag wastewater. The electrolysis unit (21) is located in the electrolysis zone (2). The electrolysis unit (21) includes an electrode (211) and an iron raw material (212). The electrode (211) is installed in the electrolysis zone (2). The electrode (211) is fixedly connected to the housing (1). The iron raw material (212) is used to provide ferrous ions to the alkaline slag wastewater. The iron raw material (212) is located in the electrolysis zone (2). The iron raw material (212) is iron shavings. The electrolysis unit (21) also includes a baffle (213), which corresponds one-to-one with the electrode (211). The baffle (213) is arranged in the electrolysis zone (2) and is connected to the box (1). The baffle (213) and its corresponding electrode (211) form a V-groove (214), which is used to accommodate iron raw material (212). The sedimentation unit (31) is used to generate ferric hydroxide flocs from the alkaline wastewater after passing through the electrolysis zone (2) and to adsorb organic matter in the alkaline wastewater using the ferric hydroxide flocs. The sedimentation unit (31) is located in the sedimentation zone (3). An overflow port (121) is provided on the upper part of the second partition (12). The overflow port (121) is used to allow the upper clear liquid in the sedimentation zone (3) to flow into the oxidation zone (4). The sedimentation unit (31) includes a coil (311), an air pipe (312), a submersible pump (313), and an ultraviolet lamp (314). The input end of the coil (311) extends through the first partition (11) into the electrolysis zone (2). The output end of the coil (311) is located above the sedimentation zone (3). The output end of the coil (311) is located above the input end of the coil (311). The submersible pump (313) is installed on the coil (311). The submersible pump (313) is used to provide power for the flow of alkaline residue wastewater. The input end of the air pipe (312) extends to the outside of the box (1). The output end of the air pipe (312) is connected to the coil (311). The ultraviolet lamp (314) and the housing (1) are fixedly connected, and the coil (311) surrounds the ultraviolet lamp (314). And an oxidation unit (41) for degrading the organic matter remaining in the alkaline residue wastewater after passing through the sedimentation zone (3), the oxidation unit (41) being located within the oxidation zone (4); The oxidation unit (41) includes a packing material (411) and an ozone aerator (412). The packing material (411) is filled in the oxidation zone (4) and is located between the overflow port (121) and the drain port (14). The ozone aerator (412) is fixedly connected to the box body (1) and is located below the packing material (411). The packing material (411) is activated carbon.

2. The alkaline residue wastewater pretreatment device as described in claim 1, characterized in that: The sedimentation unit (31) includes a venturi tube (315), the submersible pump (313) and the coil (311) are connected through the venturi tube (315), and the input end of the air pipe (312) is connected to the venturi tube (315).

3. The alkaline residue wastewater pretreatment device as described in claim 1, characterized in that: The box (1) is provided with a drain outlet (15), which is connected to the sedimentation zone (3) and is located below the sedimentation zone (3).

4. The alkaline residue wastewater pretreatment device as described in claim 1, characterized in that: The box (1) is provided with an exhaust port (16), which is located on the top surface of the box (1) and is connected to the sedimentation zone (3).

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