Tobacco wastewater efficient treatment system

Abstract

The utility model discloses an efficient tobacco wastewater treatment system which comprises a pretreatment unit, a two-stage biochemical unit, an air floatation unit, an advanced oxidation unit and a filtration and purification unit which are connected in sequence through a first transmission unit, the advanced oxidation unit is connected with the filtration and purification unit through a second transmission unit; according to the efficient treatment system for the tobacco wastewater, a combined process of pretreatment, two-stage biochemical treatment, air floatation and advanced oxidation is adopted, so that the degradation efficiency of macromolecular pollutants is effectively improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to tobacco wastewater efficient treatment system technical field, specifically related to a kind of tobacco wastewater efficient treatment system. BACKGROUND

[0002] Tobacco production discharges exhaust gas and wastewater quantity every year cannot be underestimated. Tobacco's entire life cycle damages the environment, from planting, harvesting, curing to making finished products and distributing to all over the world, and finally into the hands of consumers, damaging health. Globally, the weight of waste generated during the entire tobacco life cycle is about 25 million tons per year. The exhaust gas and wastewater generated during the production of tobacco products have additional negative impacts or damages on the environment.

[0003] The harm of tobacco wastewater mainly reflects its negative impact on soil, water and ecosystem. The harmful substances contained in tobacco wastewater can adversely affect the survival and reproduction of aquatic organisms, and may have a carcinogenic risk if the content cannot be effectively controlled.

[0004] Tobacco wastewater contains oil tobacco, nicotine, tar, essence, etc. It is very difficult to degrade and needs to develop new wastewater treatment process for its characteristics.

[0005] Defects and deficiencies of prior art:

[0006] (1) Treatment process: the existing tobacco wastewater treatment process is mostly single biochemical treatment process, with low operating cost, but it is difficult to stabilize and meet the standard. The macromolecular organic matter in tobacco wastewater is difficult to biodegrade, resulting in low efficiency and slow decline of the treatment system.

[0007] (2) Impact resistance: since tobacco wastewater is mostly mixed wastewater from the entire factory production line, the water quantity and quality fluctuate greatly, and single treatment process is difficult to resist the impact of water quantity and quality fluctuation, especially the activated sludge of biochemical process, which will cause the treatment system to be paralyzed once water shortage or high-salt wastewater impact. Utility model content

[0008] The utility model aims at overcoming the defects in prior art, providing a tobacco wastewater efficient treatment system to treat tobacco wastewater from tobacco production plant, and realizing reuse and discharge after sewage treatment.

[0009] To achieve the above purpose, the technical scheme of the utility model is to design a tobacco wastewater efficient treatment system, which comprises a pretreatment unit, two-stage biochemical unit, air flotation unit, advanced oxidation unit and filtration and purification unit connected in sequence, and the pretreatment unit, two-stage biochemical unit and air flotation unit are connected through a first transmission unit, and the advanced oxidation unit and filtration and purification unit are connected through a second transmission unit.

[0010] The pretreatment unit comprises a water inlet grille and a regulating pool, and the water inlet grille is connected with the regulating pool.

[0011] The two-stage biochemical unit comprises a hydrolytic acidification unit and a membrane bioreactor, the hydrolytic acidification unit comprises a primary sedimentation tank and a hydrolytic acidification pool, the primary sedimentation tank is connected with the hydrolytic acidification pool, and the hydrolytic acidification pool is connected with the membrane bioreactor; the membrane bioreactor comprises an anoxic pool, an aerobic pool and an ultrafiltration membrane assembly, and the anoxic pool, the aerobic pool and the ultrafiltration membrane assembly are connected in series.

[0012] The air flotation unit comprises an air flotation machine, and the air flotation machine is connected with the water outlet end of the membrane bioreactor.

[0013] The advanced oxidation unit comprises a strong oxidation water pool and a disinfection clean water pool, the water inlet end of the strong oxidation water pool is connected with the water outlet end of the air flotation machine, and the water outlet end of the strong oxidation water pool is connected with the disinfection clean water pool.

[0014] Further, it further comprises a filtration and purification unit, and the filtration and purification unit comprises an ultrafiltration membrane filter, an activated carbon filter and a depth filter connected in sequence in the water inlet direction.

[0015] Further, the pretreatment unit further comprises a water collecting pool and a first-stage lifting pump, the water outlet end of the water inlet grille is connected with the water collecting pool, the water collecting pool is connected with the regulating pool through the first-stage lifting pump, and the first-stage lifting pump is connected through a first pipeline.

[0016] The pretreatment unit further comprises an accident pool, the accident pool is connected between the first-stage lifting pump and the regulating pool, and is arranged in parallel with the first pipeline.

[0017] Further, the first transmission unit comprises a second-stage lifting pump and a third-stage lifting pump, the pretreatment unit and the two-stage biochemical unit are connected through the second-stage lifting pump, and the two-stage biochemical unit and the air flotation unit are connected through the third-stage lifting pump.

[0018] The second transmission unit comprises a fourth-stage lifting pump, and the advanced oxidation unit and the filtration and purification unit are connected through the fourth-stage lifting pump.

[0019] Further, the membrane bioreactor comprises two groups of anoxic pools and two groups of aerobic pools, the two groups of anoxic pools are a first-stage anoxic pool and a second-stage anoxic pool respectively, the two groups of aerobic pools are a first-stage aerobic pool and a second-stage aerobic pool respectively, the first-stage anoxic pool, the first-stage aerobic pool, the second-stage anoxic pool and the second-stage aerobic pool are connected in series from left to right, the first-stage anoxic pool is connected with the hydrolytic acidification pool, and the second-stage aerobic pool is connected with the ultrafiltration membrane assembly.

[0020] Further, the membrane bioreactor further comprises an intermediate water pool, the water outlet end of the ultrafiltration membrane assembly is connected with the intermediate water pool, and the other end of the intermediate water pool is connected with the air flotation machine through a three-stage lifting water pump.

[0021] Further, the membrane bioreactor further comprises an intermediate water pool, the water outlet end of the ultrafiltration membrane assembly is connected with the intermediate water pool, and the other end of the intermediate water pool is connected with the air flotation machine through a three-stage lifting water pump.

[0022] Further, the water inlet grille adopts a mechanical fine grille.

[0023] A high-efficiency treatment method for tobacco wastewater, and the treatment steps are as follows:

[0024] S1: The tobacco wastewater is collected into a pretreatment unit for pretreatment;

[0025] The pretreatment unit comprises a water inlet grille, a water collecting pool, a first-stage lifting pump, a regulating pool and an accident pool, the water outlet end of the water inlet grille is connected with the water collecting pool, the water collecting pool is connected with the regulating pool through the first-stage lifting pump, and the first-stage lifting pump and the regulating pool are connected through a first pipeline; the accident pool is connected between the first-stage lifting pump and the regulating pool and is arranged in parallel with the first pipeline. The main function of the water inlet grille is to filter large-particle pollutants in the wastewater, so as to prevent the equipment and pipelines in the subsequent treatment unit from being blocked and worn. The function of the regulating pool is to uniformly mix different concentrations of wastewater in a water quality and water quantity variation period, so as to adapt to water quality and water quantity impact load, reduce the pressure of water quality and water quantity change on the subsequent treatment facilities, and make the subsequent treatment achieve optimal removal amount and stable removal rate. The accident pool plays a role of buffering water flow impact; the pretreatment makes the water quality tend to be relatively stable, which is beneficial to the subsequent treatment.

[0026] S2: After the tobacco wastewater passes through the pretreatment unit, the wastewater enters a hydrolysis acidification unit, and after acidification for a certain time, macromolecules are degraded into small molecules;

[0027] S3: After the tobacco wastewater passes through the hydrolysis acidification unit, the wastewater enters a membrane bioreactor, and after the processes of nitrification and denitrification, most of the organic matters are removed, and the effluent enters an ultrafiltration membrane, and sludge backflow is returned to the front end of the biochemical treatment;

[0028] In step S2 and step S3, the two-stage biochemical unit comprises a hydrolysis acidification unit and a membrane bioreactor, the hydrolysis acidification unit comprises a primary sedimentation tank and a hydrolysis acidification tank, the primary sedimentation tank is connected with the hydrolysis acidification tank, and the hydrolysis acidification tank is connected with the membrane bioreactor; the hydrolysis acidification tank contains acid-producing bacteria, which hydrolyze and acidify macromolecular organic matters in wastewater into small-molecule organic acids by using the acid-producing bacteria. The membrane bioreactor comprises two groups of anoxic tanks, two groups of aerobic tanks, an ultrafiltration membrane assembly, and an intermediate tank, the two groups of anoxic tanks are a first-stage anoxic tank and a second-stage anoxic tank, the two groups of aerobic tanks are a first-stage aerobic tank and a second-stage aerobic tank, the first-stage anoxic tank, the first-stage aerobic tank, the second-stage anoxic tank, and the second-stage aerobic tank are connected in series from left to right, the first-stage anoxic tank is connected with the hydrolysis acidification tank, the second-stage aerobic tank is connected with the ultrafiltration membrane assembly, the outlet end of the ultrafiltration membrane assembly is connected with the intermediate tank, and the other end of the intermediate tank is connected with a flotation machine through a three-stage lifting water pump. The first-stage anoxic tank and the second-stage anoxic tank contain the same anaerobic bacteria, and the first-stage aerobic tank and the second-stage aerobic tank contain the same aerobic bacteria and facultative bacteria. Preferably, the ultrafiltration membrane assembly adopts a 100KD 2540 wide-flow-channel roll-type membrane, and the model is Zhongke Liyang SG-UE100-2540-G2.

[0029] The hydrolysis acidification tank improves the biodegradability, mainly reduces the molecular weight of organic matters, produces incomplete oxidation products, and is beneficial to the subsequent aerobic treatment. The two-stage anoxic tank, the two-stage aerobic tank, and the ultrafiltration membrane assembly are connected in series to form a membrane bioreactor. A large amount of microorganisms (activated sludge) in the membrane bioreactor fully contact with substrates (degradable organic matters in wastewater) to carry out metabolism through oxidation and decomposition to maintain their growth and reproduction, and at the same time, organic pollutants are degraded. The ultrafiltration membrane assembly performs solid-liquid separation on the wastewater and sludge mixture. The sludge is concentrated and returned to the membrane bioreactor, thereby avoiding the loss of microorganisms. The main features of the membrane bioreactor are as follows: high pollutant removal efficiency and good effluent water quality; strong adaptability and resistance to impact load; short process flow, simple and compact system equipment, small footprint; easy to realize automatic control, simple maintenance, and saving of manpower; fast system startup speed, and water quality can quickly meet the requirements.

[0030] S4: After the tobacco wastewater passes through the membrane bioreactor, the wastewater enters the flotation machine, a coagulant is added into the flotation machine, and the wastewater stays in the flotation machine for 0.5-1 hours; compressed air is mixed with the wastewater in a dissolved air tank under pressure, and then is sprayed and circulated, suspended matters float up with the air bubbles to form scum, and the scum is scraped off by a scum scraper;

[0031] In the flotation machine, a coagulant is added, and a dissolved air flotation process is used on the wastewater, micro-bubbles are used to take the suspended matters in the wastewater out of the water surface, so as to remove part of the SS, and the emulsified oil and total phosphorus in the wastewater are also reduced to a certain extent.

[0032] The coagulant added in step S4 is at least one of polyaluminum chloride, polyacrylamide, and polymeric ferric sulfate. The flocculants polyaluminum chloride (PAC), polymeric ferric sulfate (PFS), and polyacrylamide (PAM) have certain removal effects on suspended solids, and the combination of PAC, PFS, and PAM has strong adaptability to the raw solution; preferably, the mass concentration of PAC is 1.9 g / L (calculated by the mass of aluminum oxide), the mass concentration of PFS is 1.2 g / L (calculated by the mass of iron), the mass concentration of PAM is 0.16 g / L, and the treatment effect is best when the pH value is 8.

[0033] S5: The produced water enters a high-level oxidation unit, and the high-level oxidation unit includes a strong oxidation pool and a disinfection clean water pool, the water inlet end of the strong oxidation pool is connected with the water outlet end of the air flotation machine, and the water outlet end of the strong oxidation pool is connected with the disinfection clean water pool.

[0034] The strong oxidation pool is an ozone oxidation device, ozone reacts with wastewater rapidly, and complete and efficient chemical reactions remove COD cr , BOD5, and color, and then the ozone-oxidized wastewater enters the disinfection clean water pool for disinfection, and sodium hypochlorite is added in the disinfection clean water pool.

[0035] The ozone oxidation device uses ozone as a strong oxidizing agent to oxidize organic or inorganic substances in wastewater, and can simultaneously achieve the effects of oxidation, disinfection, and decolorization. The process unit mainly functions to remove COD cr in wastewater, fully guarantees the stability of the water outlet index, and ozone oxidation does not produce additional chemical sludge or secondary pollution, has a small footprint, and is easy to operate and maintain.

[0036] S6: The water outlet is filtered through a filtration and purification unit, and then is reused through a reuse unit.

[0037] The filtration and purification unit includes, in sequence in the water inlet direction, an ultrafiltration membrane filter, an activated carbon filter, and a depth filter. The reuse unit includes, in sequence in the water inlet direction, a reuse water pool, a reuse water pump, and a reuse pipe network. The depth filter includes a nanofiltration membrane filter and a reverse osmosis filter.

[0038] In step S6, the ultrafiltration membrane is an 80KD 2540 wide channel roll membrane, the model number of which is Zhongke Liyang SG-UE080-2540-G2; the activated carbon filter is from Wuxi Fanyu Water Treatment Machinery Manufacturing Co., Ltd., and the model number thereof is TJ-D100; the nanofiltration membrane is a 500D wide channel roll nanofiltration membrane, the model number of which is Willy DK2540C50; and the reverse osmosis membrane is a 0.5 nm RO membrane, the model number of which is Dow BW30-2540.

[0039] The sludge generated by the treatment system is lifted into a sludge centrifugal dewatering machine by a sludge feeding pump, and a proper amount of flocculant is added during the feeding process to improve the solid-liquid separation effect.The flocculant addition concentration is 0.1-0.3%, and the specific addition amount is determined according to the solid-liquid separation effect of the dewatering machine.The clear liquid generated by sludge dewatering flows into a filtrate tank and is returned to the system for treatment by a dewatering clear liquid backflow pump, the dry sludge generated by sludge dewatering has a water content of less than 80%, and the dewatered sludge after dewatering is collected by a sludge hopper, and two valves and a counterflange are reserved at the bottom of the tank.The dry sludge is transported out after being loaded into a truck.

[0040] The advantages and beneficial effects of the utility model lie in that:

[0041] (1) The tobacco wastewater efficient treatment system adopts the combined process of "pretreatment + two-stage biochemical + air flotation + advanced oxidation", which integrates the advantages of various wastewater treatment processes and solves the problems of difficult treatment and high cost of tobacco wastewater.

[0042] (2) The tobacco wastewater efficient treatment system innovates the system treatment process, including the combination of hydrolysis acidification and air flotation, which effectively improves the biodegradability and pollutant removal rate, and this mode has lower energy consumption, higher efficiency and bright application prospect.

[0043] (3) The tobacco wastewater efficient treatment system innovates the system treatment process, and the two-stage biochemical and ultrafiltration membrane are combined into a composite membrane bioreactor, which effectively improves the degradation efficiency of macromolecular pollutants and keeps the sludge concentration at a high level, so that the system maintains high activity and impact resistance.

[0044] (4) The tobacco wastewater efficient treatment system innovates the system treatment process, and the advanced oxidation can rapidly and completely reduce the pollutant indicators of the effluent, greatly guaranteeing the effluent quality, and the ozone oxidation has good removal rate on COD cr , BOD5 and color of tobacco wastewater, and does not produce secondary pollution.

[0045] (5) The tobacco wastewater efficient treatment system innovates the system treatment process, combines various treatment methods, and is concentrated in the wastewater treatment station, has high automation degree and small occupied area.

[0046] (6) The tobacco wastewater efficient treatment system adopts the combined process of "pretreatment + two-stage biochemical + air flotation + advanced oxidation", which guarantees that the wastewater of the tobacco production plant meets the standard.The pretreatment is used to remove the tobacco and other suspended solids in the wastewater, the hydrolysis acidification is used to improve the biodegradability, the two-stage biochemical is used, and the air flotation and advanced oxidation are used to guarantee that the effluent meets the standard.The system can realize external discharge and can be used for greening supplement and reused in the factory area when necessary. BRIEF DESCRIPTION OF DRAWINGS

[0047] Figure 1 This is a flowchart of the high-efficiency tobacco wastewater treatment system described in this utility model;

[0048] Figure 2 This is a schematic diagram of the efficient tobacco wastewater treatment system described in this utility model. Detailed Implementation

[0049] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings and examples. The following examples are only used to more clearly illustrate the technical solution of this utility model and should not be construed as limiting the scope of protection of this utility model.

[0050] The present invention will be further described in detail below with reference to the embodiments:

[0051] (I) Implementation Examples

[0052] Example 1:

[0053] like Figure 1 As shown, a high-efficiency tobacco wastewater treatment system includes a pretreatment unit, a two-stage biochemical unit, an air flotation unit, an advanced oxidation unit, a filtration and purification unit, and a reuse unit connected in sequence. The pretreatment unit and the two-stage biochemical unit are connected via a two-stage booster pump, and the two-stage biochemical unit and the air flotation unit are connected via a three-stage booster pump. The advanced oxidation unit and the filtration and purification unit are connected via a four-stage booster pump.

[0054] like Figure 2 As shown, the specific treatment steps for tobacco wastewater using the aforementioned high-efficiency tobacco wastewater treatment system are as follows:

[0055] S1: Tobacco wastewater is collected and enters the pretreatment unit for pretreatment;

[0056] The pretreatment unit includes an inlet screen, a collection tank, a primary booster pump, a regulating tank, and an emergency tank. The outlet end of the inlet screen is connected to the collection tank. The collection tank is connected to the regulating tank via the primary booster pump. The primary booster pump and the regulating tank are connected via a first pipeline. The emergency tank is connected between the primary booster pump and the regulating tank and is arranged in parallel with the first pipeline.

[0057] S2: After passing through the pretreatment unit, tobacco wastewater enters the hydrolysis and acidification unit. After a certain period of acidification, the macromolecules are degraded into small molecules.

[0058] S3: After passing through the hydrolysis and acidification unit, tobacco wastewater enters the membrane bioreactor. After nitrification and denitrification, most of the organic matter is removed, and the effluent enters the ultrafiltration membrane, while the sludge is retained and returned to the front end of the biological treatment.

[0059] In step S2 and step S3, the two-stage biochemical unit comprises a hydrolysis acidification unit and a membrane bioreactor, the hydrolysis acidification unit comprises a primary sedimentation tank and a hydrolysis acidification tank, the primary sedimentation tank is connected with the hydrolysis acidification tank, and the hydrolysis acidification tank is connected with the membrane bioreactor; the hydrolysis acidification tank contains acid-producing bacteria, and the acid-producing bacteria hydrolyze and acidify macromolecular organic matters in the wastewater into small-molecule organic acids.

[0060] The membrane bioreactor comprises two groups of anoxic tanks, two groups of aerobic tanks, an ultrafiltration membrane assembly, and an intermediate water tank, the two groups of anoxic tanks are a first-stage anoxic tank and a second-stage anoxic tank, the two groups of aerobic tanks are a first-stage aerobic tank and a second-stage aerobic tank, the first-stage anoxic tank, the first-stage aerobic tank, the second-stage anoxic tank, and the second-stage aerobic tank are connected in series from left to right, the first-stage anoxic tank is connected with the hydrolysis acidification tank, the second-stage aerobic tank is connected with the ultrafiltration membrane assembly, the outlet end of the ultrafiltration membrane assembly is connected with the intermediate water tank, the other end of the intermediate water tank is connected with the air flotation machine through a three-stage lifting water pump, and the first-stage anoxic tank and the second-stage anoxic tank contain the same anaerobic bacteria, and the first-stage aerobic tank and the second-stage aerobic tank contain the same aerobic bacteria and facultative bacteria.

[0061] In step S3, the ultrafiltration membrane assembly adopts a 100KD 2540 wide-flow-channel roll-type membrane with a model number of Zhongke Liyang SG-UE100-2540-G2.

[0062] S4: After the tobacco wastewater passes through the membrane bioreactor, the wastewater enters the air flotation machine, a coagulant is added into the air flotation machine, and the wastewater stays in the air flotation machine for 1 hour; compressed air is mixed with the wastewater in a dissolved air tank under pressure, and then is sprayed out and circulated; suspended matters float up with the bubbles, and form scum, which is scraped off by a scum scraper.

[0063] In step S4, the coagulant is a mixture of polyaluminum chloride (PAC), polyferric sulfate (PFS), and polyacrylamide (PAM), the mass concentration of PAC is 1.9 g / L (calculated based on the mass of aluminum oxide), the mass concentration of PFS is 1.2 g / L (calculated based on the mass of iron), the mass concentration of PAM is 0.16 g / L, and the pH value is 8.

[0064] S5: The produced water enters a high-level oxidation unit, the high-level oxidation unit comprises a strong oxidation water tank and a disinfection clean water tank, the inlet end of the strong oxidation water tank is connected with the outlet end of the air flotation machine, and the outlet end of the strong oxidation water tank is connected with the disinfection clean water tank.

[0065] In step S5, the strong oxidation water tank is an ozone oxidation device, ozone reacts rapidly with the wastewater to remove COD cr , BOD5, and color, and then the ozone-oxidized wastewater enters the disinfection clean water tank for disinfection; sodium hypochlorite is added into the disinfection clean water tank, and the addition amount of the sodium hypochlorite is 15 g / L.

[0066] S6: The water is filtered by the filtration and purification unit, and then reused by the reuse unit.

[0067] The filtration and purification unit comprises, in sequence in the direction of water inflow, an ultrafiltration membrane filter, an activated carbon filter, and a depth filter. The depth filter comprises a nanofiltration membrane filter and a reverse osmosis filter. The reuse unit comprises, in sequence in the direction of water inflow, a reuse water tank, a reuse water pump, and a reuse pipe network.

[0068] In step S6, the ultrafiltration membrane is a 80KD 2540 wide channel roll type membrane, model: Zhongke Liyang SG-UE080-2540-G2.

[0069] The activated carbon filter is from Wuxi Fanyu Water Treatment Machinery Manufacturing Co., Ltd., model TJ-D100.

[0070] The nanofiltration membrane is a 500D wide channel roll type nanofiltration membrane, model: WILK DK2540C50.

[0071] The reverse osmosis membrane is a 0.5nm RO membrane, model: Dow BW30-2540.

[0072] Comparative Example 1

[0073] The difference from Example 1 is only that the sequence of the air flotation unit and the two-stage biochemical unit is exchanged, that is, the air flotation unit is used after the pretreatment unit, and then the two-stage biochemical unit is used.

[0074] Comparative Example 2

[0075] The difference from Example 1 is only that the membrane bioreactor is different. In this comparative example, the membrane bioreactor comprises a first anoxic tank, a first aerobic tank, an ultrafiltration membrane assembly, and an intermediate water tank. The first anoxic tank, the first aerobic tank, and the ultrafiltration membrane assembly are connected in sequence from left to right. The outlet end of the ultrafiltration membrane assembly is connected to the intermediate water tank. The other end of the intermediate water tank is connected to the air flotation machine through a three-stage lifting water pump.

[0076] Comparative Example 3

[0077] The difference from Example 1 is only that the membrane bioreactor is different. In this comparative example, the membrane bioreactor comprises two groups of anoxic tanks, two groups of aerobic tanks, and an intermediate water tank. The two groups of anoxic tanks are a first anoxic tank and a second anoxic tank. The two groups of aerobic tanks are a second anoxic tank and a second aerobic tank. The first anoxic tank, the first aerobic tank, the second anoxic tank, and the second aerobic tank are connected in sequence from left to right. The first anoxic tank is connected to the hydrolysis acidification tank. The second aerobic tank is connected to the intermediate water tank. The other end of the intermediate water tank is connected to the air flotation machine through a three-stage lifting water pump.

[0078] Comparative Example 4:

[0079] The difference from Example 1 is that in step S4, the coagulant is polyaluminum chloride (PAC), and the mass concentration of PAC is 3.26 g / L (calculated by the mass of aluminum oxide).

[0080] Comparative Example 5:

[0081] The difference from Example 1 is that in step S4, the coagulant is polyferric sulfate (PFS), and the mass concentration of PFS is 3.26 g / L (calculated by the mass of iron).

[0082] Comparative Example 6:

[0083] The difference from Example 1 is that in step S4, the coagulant is polyferric sulfate (PFS), and the mass concentration of PAM is 3.26 g / L.

[0084] Comparative Example 7:

[0085] The difference from Example 1 is that in step S4, the pH value is 6.

[0086] Comparative Example 8:

[0087] The difference from Example 1 is that in step S4, the pH value is 7.

[0088] Comparative Example 9:

[0089] The difference from Example 1 is that in step S4, the pH value is 9.

[0090] Comparative Example 10:

[0091] The difference from Example 1 is that there is no advanced oxidation unit.

[0092] Comparative Example 11:

[0093] The difference from Example 1 is that after the two-stage biochemical unit treatment, the advanced oxidation unit treatment is carried out first, and then the air flotation unit treatment is carried out, that is, the sequence of the air flotation unit and the advanced oxidation unit treatment is different.

[0094] (II) Performance test

[0095] BOD5 (mg / L) COD Cr (mg / L) SS (mg / L) pH Color (times) Wastewater raw liquid 6200 24000 15700 6.3 14000 Example 1 14 55 40 6.5 15 Comparative Example 1 290 590 480 6.4 35 Comparative Example 2 480 760 270 6.5 48 Comparative Example 3 420 680 350 6.4 40 Comparative Example 4 85 120 150 6.3 32 Comparative Example 5 94 160 170 6.3 45 Comparative Example 6 70 109 138 6.4 38 Comparative Example 7 95 115 141 6.2 32 Comparative Example 8 86 121 152 6.7 45 Comparative Example 9 140 154 190 7.2 48 Comparative Example 10 1040 2430 960 6.5 1370 Comparative Example 11 92 119 171 6.4 55

[0096] From the above examples and comparative examples, it can be seen that the tobacco wastewater efficient treatment system adopts the combined process of “pretreatment + two-stage biochemical + air flotation + advanced oxidation”, which effectively improves the degradation efficiency of macromolecular pollutants, and at the same time, the sludge concentration is always kept at a high level, so that the system maintains high activity and impact resistance.

[0097] The above merely describes preferred embodiments of the present application, and it should be noted that, for those skilled in the art, without departing from the technical principles of the present application, a number of improvements and refinements can be made, and these improvements and refinements should also be considered within the protection scope of the present application.

Claims

1. A high-efficiency tobacco wastewater treatment system, characterized in that, It includes a pretreatment unit, a two-stage biochemical unit, an air flotation unit, an advanced oxidation unit, and a filtration and purification unit connected in sequence. The pretreatment unit, the two-stage biochemical unit, and the air flotation unit are connected through a first transmission unit, and the advanced oxidation unit and the filtration and purification unit are connected through a second transmission unit. The two-stage biochemical unit includes a hydrolysis acidification unit and a membrane bioreactor. The hydrolysis acidification unit includes a primary sedimentation tank and a hydrolysis acidification tank, which are connected to each other. The hydrolysis acidification tank is also connected to the membrane bioreactor. The membrane bioreactor includes an anoxic tank, an aerobic tank, and an ultrafiltration membrane module, which are connected in series.

2. The efficient tobacco wastewater treatment system according to claim 1, characterized in that, The pretreatment unit includes an inlet bar and a regulating tank, wherein the inlet bar is connected to the regulating tank. The air flotation unit includes an air flotation machine, which is connected to the outlet end of the membrane bioreactor. The advanced oxidation unit includes a strong oxidation water tank and a disinfection water tank. The inlet of the strong oxidation water tank is connected to the outlet of the air flotation machine, and the outlet of the strong oxidation water tank is connected to the disinfection water tank. The filtration and purification unit includes an ultrafiltration membrane filter, an activated carbon filter, and a depth filter connected in sequence in the direction of water inlet.

3. The efficient tobacco wastewater treatment system according to claim 2, characterized in that, The pretreatment unit also includes a water collection tank and a primary booster pump. The outlet end of the water inlet bar is connected to the water collection tank. The water collection tank is connected to the regulating tank through the primary booster pump. The primary booster pump and the regulating tank are connected through a first pipeline. The pretreatment unit also includes an emergency pool, which is connected between the primary booster pump and the regulating pool, and is arranged in parallel with the first pipeline.

4. The efficient tobacco wastewater treatment system according to claim 1, characterized in that, The first transmission unit includes a two-stage booster pump and a three-stage booster pump. The pretreatment unit is connected to the two-stage biochemical unit via the two-stage booster pump, and the two-stage biochemical unit is connected to the air flotation unit via the three-stage booster pump. The second transmission unit includes a four-stage booster pump, and the advanced oxidation unit and the filtration and purification unit are connected via the four-stage booster pump.

5. The efficient tobacco wastewater treatment system according to claim 4, characterized in that, The membrane bioreactor includes two sets of anoxic tanks and two sets of aerobic tanks. The two sets of anoxic tanks are a first-stage anoxic tank and a second-stage anoxic tank, respectively. The first-stage anoxic tank, the first-stage aerobic tank, the second-stage anoxic tank, and the second-stage aerobic tank are connected in series from left to right. The first-stage anoxic tank is connected to the hydrolysis acidification tank, and the second-stage aerobic tank is connected to the ultrafiltration membrane module.

6. The efficient tobacco wastewater treatment system according to claim 5, characterized in that, The membrane bioreactor also includes an intermediate water tank, the outlet end of the ultrafiltration membrane module is connected to the intermediate water tank, and the other end of the intermediate water tank is connected to the air flotation machine through a three-stage lift pump.

7. The efficient tobacco wastewater treatment system according to claim 5, characterized in that, It also includes a reuse unit, which is connected to the filtration and purification unit. The reuse unit includes a reuse water tank, a reuse water pump, and a reuse pipeline connected in sequence in the direction of water inlet.

8. The efficient tobacco wastewater treatment system according to claim 2, characterized in that, The inlet screen is a mechanical fine screen.

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