Toluene-containing industrial wastewater treatment device

Abstract

The utility model relates to the technical field of industrial wastewater treatment, in particular to a toluene-containing industrial wastewater treatment device. The toluene-containing industrial wastewater treatment device comprises an adjusting tank, the adjusting tank is connected with an iron-carbon reactor through a neutralization sedimentation tank, the iron-carbon reactor is connected with a sedimentation tank through a Fenton reactor, the sedimentation tank is connected with a high-efficiency anaerobic reactor through a triple-effect evaporator, the high-efficiency anaerobic reactor is connected with an aerobic tank through a hydrolysis acidification tank, and the aerobic tank is connected with an aerobic tank. Volcanic colored glaze ball filler and an anaerobic aeration plate are arranged in the efficient anaerobic reactor. According to the device, the regulating tank and the neutralization sedimentation tank are used in cooperation, NaOH, PAC, PAM and Ca (OH) 2 are added into the regulating tank and the neutralization sedimentation tank, aluminum hydroxide is precipitated, then the aluminum hydroxide enters the plate and frame machine for dehydration, solid-liquid separation is achieved, and the problem that filter cloth of the plate and frame machine is blocked is solved.

Description

Technical Field

[0001] The utility model relates to the technical field of industrial wastewater treatment, in particular to a device for treating industrial wastewater containing toluene. Background Art

[0002] Industrial wastewater containing toluene contains multiple organic components such as methanol, toluene, methyl acrylate, and acrylic acid. Among them, methanol, acrylic acid, and methyl acrylate are relatively easy to biodegrade. However, toluene has poor biodegradability and requires a long time of domestication. Moreover, toluene wastewater has a wide pollution range and complex discharge methods; the pollutant concentration fluctuates greatly; the pollutants are highly toxic and harmful, can consume the dissolved oxygen in the water, and cause water hypoxia, resulting in the death of aquatic organisms.

[0003] In the existing device, since the industrial wastewater containing toluene also contains aluminum elements, after adjusting the pH to neutral, a large amount of aluminum hydroxide precipitate generated is very viscous, resulting in the problem of clogging the filter cloth of the plate-and-frame filter press; moreover, a large amount of Fe 2+ and Fe 3 + remaining in the wastewater is very unfavorable for the subsequent biochemical treatment, and the above problems have not been solved in the existing treatment process. At the same time, the toxicity of toluene has a strong inhibitory effect on microorganisms, and it cannot be deeply treated to meet the discharge standards. Content of the Utility Model

[0004] According to the above deficiencies in the prior art, the purpose of the utility model is to provide a device for treating industrial wastewater containing toluene. By using a regulating tank and a neutralization sedimentation tank in combination, adding NaOH, PAC, PAM, and Ca(OH)2 to generate aluminum hydroxide precipitate, and then entering the plate-and-frame filter press for dehydration to separate solids and liquids, avoiding the problem of clogging the filter cloth of the plate-and-frame filter press; after Fenton oxidation, a large amount of Fe 2+ and Fe 3+ remain in the wastewater. Adjust the pH with NaOH solution to make Fe 2+ and Fe 3+ in the solution exist in the forms of Fe(OH)2 and Fe(OH)3 respectively. In order to improve the sedimentation effect of the flocs, add coagulants PAM and PAC to the wastewater after adding alkali, so that the generated fine colloidal precipitates form larger flocs, which can sediment at a faster speed and improve the wastewater treatment efficiency.

[0005] The utility model is realized by adopting the following technical solutions:

[0006] The described industrial wastewater treatment device containing toluene includes an adjustment tank, which is connected to an iron-carbon reactor through a neutralization sedimentation tank. The iron-carbon reactor is connected to a sedimentation tank through a Fenton reactor. The sedimentation tank is connected to a high-efficiency anaerobic reactor through a triple-effect evaporator. The high-efficiency anaerobic reactor is connected to an aerobic tank through a hydrolysis acidification tank. Inside the high-efficiency anaerobic reactor, there are volcanic rock glass ball fillers and anaerobic aeration plates.

[0007] There is a lift pump between the adjustment tank and the neutralization sedimentation tank. The adjustment tank is used to collect wastewater. Inside the neutralization sedimentation tank, there is a stirring device, and NaOH, PAC, PAM, and Ca(OH)2 are added to it. Hydrochloric acid is added to the iron-carbon reactor, and iron-carbon fillers are provided in the iron-carbon reactor. Hydrogen peroxide and ferric sulfate are added to the Fenton reactor. NaOH, PAC, and PAM are added to the sedimentation tank.

[0008] The described industrial wastewater treatment device containing toluene also includes a sludge thickening tank, which is connected to a sludge conditioning tank through a sludge inlet pipeline. The sludge conditioning tank is connected to a diaphragm plate and frame filter press through a pipeline leading to the filter press.

[0009] There is a No. 1 intermediate water tank between the neutralization sedimentation tank and the iron-carbon reactor, and a No. 2 intermediate water tank between the sedimentation tank and the triple-effect evaporator.

[0010] There is a biochemical adjustment tank between the triple-effect evaporator and the high-efficiency anaerobic reactor. Inside the biochemical adjustment tank, there is a biochemical adjustment tank stirrer. The aerobic tank is connected to a clear water tank through a secondary sedimentation tank.

[0011] The volcanic rock glass ball fillers are located above the anaerobic aeration plates. There is a filler support between the volcanic rock glass ball fillers and the anaerobic aeration plates. A grille is provided on the filler support. Inside the high-efficiency anaerobic reactor, there is an internal reflux pump, and an anaerobic blower is connected to the anaerobic aeration plates.

[0012] Inside the hydrolysis acidification tank, there is a hydrolysis acidification tank stirrer. Inside the aerobic tank, there is an aerobic tank aeration plate, and an aerobic tank blower is connected to the aerobic tank aeration plate.

[0013] The neutralization sedimentation tank is connected to the pipeline leading to the filter press through a pipeline out of the neutralization sedimentation tank. The sedimentation tank is connected to the sludge inlet pipeline through a pipeline out of the sedimentation tank.

[0014] The triple-effect evaporator is connected to the pipeline out of the sedimentation tank through a pipeline out of the triple-effect evaporator. A plate-type bottom-discharge centrifuge is connected to the sludge inlet pipeline.

[0015] The working principle of the present utility model is as follows:

[0016] The first step: the dehydrogenation and aluminum hydroxide process:

[0017] Collect the mixed wastewater uniformly, adjust the pH of the wastewater to around 7 - 8 by adding lye, add PAC, PAM, and Ca(OH)₂, and after precipitation, enter the plate and frame filter press for dehydration to separate the solid and liquid. Using a coagulant aid can not only neutralize the pH of the wastewater but also help with precipitation. It can be directly dehydrated into a mud cake from the plate and frame filter press. The filtrate generated after separation is collected and used as the influent for pretreatment. The water content of the filter cake is about 60%, and it can be fully considered for treatment as a by-product.

[0018] Step 2: Pretreatment process:

[0019] 1. Re - adjust the pH of the separated supernatant with hydrochloric acid, and select iron - carbon micro - electrolysis as the first step of the pretreatment process. The principle of this treatment method is that the iron and carbon components in the iron - carbon stone form the positive and negative electrodes of a tiny primary battery, with the influent wastewater as the electrolyte solution, and an oxidation - reduction reaction occurs to form a primary battery. Iron - carbon micro - electrolysis can have good effects in treating wastewater with high organic matter concentration, high toxicity, and difficult biodegradability. It can break large molecular chains into slightly smaller small - molecular - chain substances, and the iron - carbon micro - electrolysis filler has good treatment effects on benzene - series wastewater.

[0020] 2. Select Fenton oxidation as the second step of comprehensive pretreatment, which can oxidize most substances in water, oxidize and decompose the refractory organic matter in the sewage into small - molecular organic matter and inorganic substances, and achieve the degradation of organic matter. The removal rate of toluene by the Fenton reaction is up to over 88%. After Fe / C micro - electrolysis and Fenton oxidation, the COD of the wastewater is greatly reduced, and BOD5 / COD is also improved to a large extent.

[0021] 3. However, a large amount of residual Fe 2+ and Fe 3+ in the wastewater is very unfavorable for the subsequent biochemical treatment. Therefore, in the follow - up, use NaOH solution to adjust the pH, and at the same time make Fe 2+ and Fe 3+ exist in the form of Fe(OH)₂ and Fe(OH)₃ respectively. To improve the sedimentation effect of the flocs, coagulant aids PAM and PAC can be added to the wastewater after adding alkali, so that the generated fine colloids precipitate to form larger flocs, which then settle at a faster speed and enter the subsequent triple - effect evaporation for desalination.

[0022] Step 3: Evaporation and desalination process

[0023] Since the salt content of this wastewater is relatively high, the wastewater undergoes Fe / C micro - electrolysis and Fenton oxidation in the early stage and then enters the triple - effect for evaporation and desalination. The distilled water enters the biochemical system. After the concentrated water is centrifuged, the waste salt is identified and treated as solid waste, and the wastewater returns to the pretreatment process.

[0024] Step 4: Biochemical treatment process

[0025] 1. The process combination of anaerobic fixed bed + hydrolysis acidification + aerobic treatment + secondary sedimentation tank is adopted. For refractory organic wastewater, the anaerobic fixed bed technology can effectively increase the sludge concentration, enhance the toxicity resistance of the whole biochemical system, and enhance its treatment capacity for characteristic factors such as phenol and toluene.

[0026] 2. The anaerobic fixed bed can further carry out reduction reactions on refractory organic matter, break the ring and chain, and improve biodegradability. The fixed bed anaerobic reactor adopts a relatively mature anaerobic fixed bed technology, that is, using fixed bed fillers, an anaerobic aeration plate for standby equipment below, and floating ball fillers accounting for 40% of the pool volume attached above. The metabolism of anaerobic microorganisms for the cleavage of rings in heterocyclic compounds and polycyclic aromatic hydrocarbons is different from that of aerobic microorganisms. Its cleavage is divided into reductive cleavage and non-reductive cleavage, which can degrade COD to the maximum extent and reduce the load for subsequent aerobic biochemistry.

[0027] 3. A treatment method that uses aerobic microorganisms to carry out biological metabolism in the presence of an oxygen source to degrade organic matter and make it stable and harmless. Microorganisms use the organic pollutants existing in the water as substrates for aerobic metabolism, so that the wastewater can finally meet the discharge standards.

[0028] Compared with the prior art, the beneficial effects of the present utility model are as follows:

[0029] By using the toluene-containing industrial wastewater treatment device of the present utility model and through the coordinated use of the regulating tank and the neutralization sedimentation tank, adding NaOH, PAC, PAM, and Ca(OH)2 therein to form a precipitate of aluminum hydroxide, and then entering the plate and frame filter press for dehydration to separate solids from liquids, the problem of blockage of the filter cloth of the plate and frame filter press is avoided.

[0030] After Fenton oxidation, a large amount of Fe 2+ and Fe 3+ remain in the wastewater. The pH is adjusted with NaOH solution to make Fe 2+ and Fe 3+ exist in the form of Fe(OH)2 and Fe(OH)3 respectively in the solution. In order to improve the sedimentation effect of the flocs, coagulants PAM and PAC are added to the wastewater after adding alkali, so that the generated fine colloidal precipitates form larger flocs, which can sediment at a faster speed and improve the wastewater treatment efficiency.

[0031] Using the anaerobic fixed bed technology increases the sludge concentration, enhances its adhesion and toxicity resistance, and has a good decomposition ability for incompletely oxidized toluene wastewater. The subsequent supporting process combination of hydrolysis acidification + aerobic treatment + secondary sedimentation tank can deeply treat the decomposed pollutants to meet the subsequent "Quality Standard for Wastewater Discharged into Urban Sewers" (GB / T 31962 - 2015). Description of the Drawings

[0032] Figure 1 This is a schematic structural diagram of the toluene-containing industrial wastewater treatment device of the present utility model;

[0033] Figure 2 This is a schematic structural diagram of the high-efficiency anaerobic reactor of the present utility model;

[0034] In the figure: 1, regulating tank; 2, neutralization sedimentation tank; 3, 1# intermediate water tank; 4, iron-carbon reactor; 5, Fenton reactor; 6, sedimentation tank; 7, 2# intermediate water tank; 8, triple-effect evaporator; 9, biochemical regulating tank; 10, high-efficiency anaerobic reactor; 11, hydrolysis acidification tank; 12, aerobic tank; 13, secondary sedimentation tank; 14, clear water tank; 15, sludge thickening tank; 16, sludge conditioning tank; 17, diaphragm plate and frame filter press; 18, flat-bottom discharging centrifuge; 19, stirrer of biochemical regulating tank; 20, volcanic rock glass ball filler; 21, filler support; 22, anaerobic aeration plate; 23, internal reflux pump; 24, grille; 25, anaerobic blower; 26, stirrer of hydrolysis acidification tank; 27, aerobic tank aeration plate; 28, aerobic tank blower; 29, pipeline for sludge entering the conditioning tank; 30, pipeline for entering the filter press; 31, pipeline for discharging from the neutralization sedimentation tank; 32, pipeline for discharging from the sedimentation tank; 33, pipeline for discharging from the triple-effect evaporator. Specific embodiments

[0035] In order to make the purpose and technical solutions of the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings.

[0036] Example 1

[0037] As Figure 1 shown, the toluene-containing industrial wastewater treatment device includes a regulating tank 1. The regulating tank 1 is connected to an iron-carbon reactor 4 through a neutralization sedimentation tank 2. The iron-carbon reactor 4 is connected to a sedimentation tank 6 through a Fenton reactor 5. The sedimentation tank 6 is connected to a high-efficiency anaerobic reactor 10 through a triple-effect evaporator 8. The high-efficiency anaerobic reactor 10 is connected to an aerobic tank 12 through a hydrolysis acidification tank 11. As Figure 2As shown in the figure, a volcanic rock glazed ball filler 20 and an anaerobic aeration plate 22 are provided inside the high-efficiency anaerobic reactor 10. A lift pump is provided between the regulating tank 1 and the neutralization sedimentation tank 2. The regulating tank is used to collect wastewater. A stirring device is provided inside the neutralization sedimentation tank 2, and NaOH, PAC, PAM, and Ca(OH)2 are added therein. There is a sludge thickening tank 15. The sludge thickening tank 15 is connected to the sludge conditioning tank 16 through the sludge inlet pipe 29. The sludge conditioning tank 16 is connected to the diaphragm plate and frame filter press 17 through the filter press inlet pipe 30. There is a No. 1 intermediate water tank 3 between the neutralization sedimentation tank 2 and the iron-carbon reactor 4. There is a No. 2 intermediate water tank 7 between the sedimentation tank 6 and the triple-effect evaporator 8. There is a biochemical conditioning tank 9 between the triple-effect evaporator 8 and the high-efficiency anaerobic reactor 10. A biochemical conditioning tank stirrer 19 is provided inside the biochemical conditioning tank 9. The aerobic tank 12 is connected to the clear water tank 14 through the secondary sedimentation tank 13. The volcanic rock glazed ball filler 20 is located above the anaerobic aeration plate 22. A filler support 21 is provided between the volcanic rock glazed ball filler 20 and the anaerobic aeration plate 22. A grille 24 is provided on the filler support 21. An internal reflux pump 23 is provided inside the high-efficiency anaerobic reactor 10. The anaerobic aeration plate 22 is connected to an anaerobic blower 25. A hydrolysis acidification tank stirrer 26 is provided inside the hydrolysis acidification tank 11. An aerobic tank aeration plate 27 is provided inside the aerobic tank 12. The aerobic tank aeration plate 27 is connected to an aerobic tank blower 28. The neutralization sedimentation tank 2 is connected to the filter press inlet pipe 30 through the neutralization sedimentation tank outlet pipe 31. The sedimentation tank 6 is connected to the sludge inlet pipe 29 through the sedimentation tank outlet pipe 32. The triple-effect evaporator 8 is connected to the sedimentation tank outlet pipe 32 through the triple-effect evaporator outlet pipe 33. A plate-type bottom discharge centrifuge 18 is connected to the sludge inlet pipe 29.

[0038] When the above toluene-containing industrial wastewater treatment device works, it includes the following steps:

[0039] (1) The mixed wastewater is uniformly collected into the regulating tank 1 and enters the neutralization sedimentation tank 2 for treatment. NaOH, PAC, PAM, and Ca(OH)2 are added. After precipitation, it enters the diaphragm plate and frame filter press 17 for dehydration to separate solid from liquid. (2) In the iron-carbon reactor 4, the supernatant after separation is re-adjusted in pH with hydrochloric acid. Iron-carbon microelectrolysis is selected as the first step of the pretreatment process. In the Fenton reactor 5, Fenton oxidation is selected as the second step of the comprehensive pretreatment, which can oxidize most substances in the water, decompose the refractory organic matter in the sewage into small molecule organic matter and inorganic substances, and achieve the degradation of organic matter. Coagulant aids PAM and PAC are added to the wastewater after adding alkali, so that the generated fine colloids precipitate to form larger flocs, and then settle at a faster speed and enter the triple-effect evaporator 8 for evaporation and desalination. The evaporated water enters the biochemical system. After the concentrated water is centrifuged, the waste salt is treated as solid waste after identification, and the wastewater returns to the pretreatment process. (3) For the biochemical treatment process, a process combination of anaerobic fixed bed + hydrolysis acidification + aerobic treatment + secondary sedimentation tank is used to treat the wastewater. In the aerobic tank 12, aerobic microorganisms are used to carry out biological metabolism to degrade organic matter under the condition of the presence of an oxygen source, so as to achieve stable and harmless treatment.

Claims

1. A toluene-containing industrial wastewater treatment device, characterized in that: The invention comprises a regulating tank (1), wherein the regulating tank (1) is connected to an iron-carbon reactor (4) via a neutralization sedimentation tank (2), the iron-carbon reactor (4) is connected to a sedimentation tank (6) via a Fenton reactor (5), the sedimentation tank (6) is connected to a high-efficiency anaerobic reactor (10) via a triple-effect evaporator (8), the high-efficiency anaerobic reactor (10) is connected to an aerobic tank (12) via a hydrolysis acidification tank (11), and a volcanic rock glass ball filler (20) and an anaerobic aeration plate (22) are arranged inside the high-efficiency anaerobic reactor (10).

2. The toluene-containing industrial wastewater treatment device according to claim 1, characterized in that: The invention also comprises a sludge concentration tank (15), wherein the sludge concentration tank (15) is connected to the sludge conditioning tank (16) via a sludge conditioning tank inlet pipeline (29), and the sludge conditioning tank (16) is connected to the diaphragm plate and frame filter press (17) via a filter press inlet pipeline (30).

3. The toluene-containing industrial wastewater treatment device according to claim 1, characterized in that: A No. 1 intermediate water tank (3) is provided between the neutralization sedimentation tank (2) and the iron-carbon reactor (4), and a No. 2 intermediate water tank (7) is provided between the sedimentation tank (6) and the triple-effect evaporator (8).

4. The toluene-containing industrial wastewater treatment device according to claim 1, characterized in that: A biochemical regulating tank (9) is provided between the triple-effect evaporator (8) and the high-efficiency anaerobic reactor (10), a biochemical regulating tank agitator (19) is provided in the biochemical regulating tank (9), and the aerobic tank (12) is connected to the clear water tank (14) through the secondary sedimentation tank (13).

5. The toluene-containing industrial wastewater treatment device according to claim 1, characterized in that: The volcanic rock glass ball filler (20) is located above the anaerobic aeration plate (22), a filler support (21) is provided between the volcanic rock glass ball filler (20) and the anaerobic aeration plate (22), a grid (24) is provided on the filler support (21), an internal reflux pump (23) is provided inside the high-efficiency anaerobic reactor (10), and an anaerobic fan (25) is connected to the anaerobic aeration plate (22).

6. The toluene-containing industrial wastewater treatment device according to claim 1, characterized in that: The hydrolysis acidification tank (11) is provided with a hydrolysis acidification tank agitator (26), the aerobic tank (12) is provided with an aerobic tank aeration plate (27), and the aerobic tank aeration plate (27) is connected to an aerobic tank fan (28).

7. The toluene-containing industrial wastewater treatment device according to claim 2, characterized in that: The neutralization sedimentation tank (2) is connected to the filter press inlet pipe (30) through the neutralization sedimentation tank outlet pipe (31), and the sedimentation tank (6) is connected to the sludge conditioning tank inlet pipe (29) through the sedimentation tank outlet pipe (32).

8. The toluene-containing industrial wastewater treatment device according to claim 7, characterized in that: The triple-effect evaporator (8) is connected to the sedimentation tank outlet pipeline (32) through the triple-effect evaporator outlet pipeline (33), and the sludge conditioning tank inlet pipeline (29) is connected to a flat-plate bottom-discharging centrifuge (18).

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