Bamboo product cooking wastewater treatment system

Abstract

The utility model discloses a treatment system for bamboo product cooking wastewater. The treatment system comprises a pH regulating tank, an air flotation device, an EGSB anaerobic reactor, an anaerobic sedimentation tank, an AOAO tank, a built-in MBR tank, an intermediate water tank, an ozone contact oxidation tank and a biological denitrification tank which are sequentially arranged along the treatment flow direction of the bamboo product cooking wastewater, a biogas desulfurization device, a biogas storage tank and a biogas combustion device which are connected in sequence are arranged on an exhaust port of the EGSB anaerobic reactor; sludge outlets of the air flotation device, the anaerobic sedimentation tank and the built-in MBR tank are connected with a sludge concentration tank; and the sludge concentration tank is connected with a sludge dewatering machine. According to the utility model, through pretreatment, anaerobic biochemical treatment, two-stage biochemical strengthening treatment and advanced ozone oxidation and efficient biological denitrification treatment, multi-stage strengthening treatment on high-concentration bamboo product cooking wastewater is realized, the concentration of pollutants such as COD (Chemical Oxygen Demand) is reduced, and the requirements of pipe arrangement or discharge to a downstream sewage plant are met.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a treatment system for bamboo product cooking wastewater. Background Art

[0002] Bamboo product cooking wastewater is acidic, with a pH of around 3-4, and is characterized by high COD, suspended solids, and total nitrogen. COD levels typically range from 10,000 to 100,000 mg / L, making it a high-concentration organic wastewater. Direct discharge of this high-concentration wastewater without treatment will severely pollute the receiving water bodies, ultimately endangering the ecological health of these water bodies.

[0003] The high concentration of organic matter in bamboo product cooking wastewater is primarily composed of organic acids, with acetic acid being the predominant component. It also contains oxalic acid, amino acids, and plant pigments, resulting in a red to brownish-black color. Based on its chemical composition, this wastewater is highly biodegradable and suitable for biochemical treatment. However, the COD content of bamboo product cooking wastewater is high, and the water volume is low. For decentralized home-based workshops, the wastewater is generally collected separately and transported for dilution and disposal.

[0004] With the stringent environmental protection requirements and economic development, bamboo product companies have undergone industry elimination and screening, mergers and acquisitions, and have gradually developed from the original scattered family workshops to large-scale and industrialized development. The bamboo industry has been concentrated in demonstration parks, and the demand for the construction of centralized bamboo product wastewater treatment facilities has increased. Therefore, there is an urgent need for a treatment system that can achieve stable compliance with standards for high-concentration bamboo product cooking wastewater. Utility Model Content

[0005] Aiming at the deficiencies in the prior art, the utility model provides a system for treating bamboo product cooking wastewater.

[0006] The utility model discloses a bamboo product cooking wastewater treatment system, comprising: a pH regulating tank, an air flotation device, an EGSB anaerobic reactor, an anaerobic sedimentation tank, an AOAO tank, a built-in MBR tank, an intermediate water tank, an ozone contact oxidation tank and a biological denitrification tank, which are sequentially arranged along the treatment flow direction of the bamboo product cooking wastewater;

[0007] The exhaust port of the EGSB anaerobic reactor is provided with a biogas desulfurization device, a biogas storage tank and a biogas combustion device which are connected in sequence;

[0008] The sludge outlets of the air flotation device, the anaerobic sedimentation tank and the built-in MBR tank are connected to the sludge concentration tank, and the sludge concentration tank is connected to the sludge dewatering machine.

[0009] As a further improvement of the present invention, the pH adjustment tank is equipped with a sodium hydroxide dosing device for adding sodium hydroxide solution into the pH adjustment tank to adjust the pH of the wastewater to 7-8; the pH adjustment tank is equipped with an agitator for preventing suspended particles from settling.

[0010] As a further improvement of the present invention, the flotation device adopts a dissolved air flotation tank, the front end of which is equipped with a coagulation stirring tank and a flocculation stirring tank, the coagulation stirring tank is equipped with a coagulation dosing device, and the flocculation stirring tank is equipped with a flocculation dosing device.

[0011] As a further improvement of the present invention, the AOAO pool is divided into a first-level A pool, a first-level O pool, a second-level A pool, and a second-level O pool; both the first-level A pool and the second-level A pool are provided with submersible flow propellers, and both the first-level O pool and the second-level O pool are provided with liftable aerators.

[0012] As a further improvement of the present invention, the EGSB anaerobic reactor includes a mixing zone, a sludge bulking zone, a sedimentation zone and a separation zone, and is equipped with an anaerobic water distributor, a hydraulic circulation system and a three-phase separation system. The anaerobic water distributor adopts a single-tube injection full-coverage water distribution type, and the hydraulic circulation system is provided with a circulation pump. Through forced hydraulic internal circulation, the effluent and the raw water are evenly mixed; the three-phase separation system adopts a two-stage two-phase separation device, which first performs gas-liquid separation and then solid-liquid separation.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The utility model realizes multi-stage enhanced treatment of high-concentration bamboo product cooking wastewater through pretreatment, anaerobic biochemical treatment, two-stage biochemical enhanced treatment and ozone advanced oxidation + high-efficiency biological denitrification deep treatment, reduces the concentration of pollutants such as COD, meets the requirements of pipelining or discharge to downstream sewage treatment plants, reduces pollution emissions, maintains ecological environmental safety, and has good social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a framework diagram of the bamboo product cooking wastewater treatment system disclosed in the present utility model.

[0016] In the picture:

[0017] 1. pH adjustment tank; 2. Flotation device; 3. EGSB anaerobic reactor; 4. Anaerobic sedimentation tank; 5. AOAO tank; 6. Built-in MBR membrane tank; 7. Intermediate water tank; 8. Ozone contact oxidation tank; 9. Biological denitrification tank; 10. Biogas desulfurization device; 11. Biogas storage tank; 12. Biogas combustion device; 13. Sludge thickening tank; 14. Sludge dewatering machine. DETAILED DESCRIPTION

[0018] To make the purpose, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the embodiments described are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0019] The present invention is described in further detail below with reference to the accompanying drawings:

[0020] like Figure 1 As shown, the utility model provides a bamboo product cooking wastewater treatment system, comprising: a pH adjustment tank 1, an air flotation device 2, an EGSB anaerobic reactor 3, an anaerobic sedimentation tank 4, an AOAO tank (two-stage AO treatment tank) 5, a built-in MBR tank 6, an intermediate water tank 7, an ozone contact oxidation tank 8, and a biological denitrification tank 9, which are sequentially arranged along the treatment flow direction of the wastewater. The exhaust port of the EGSB anaerobic reactor 3 is provided with a biogas desulfurization device 10, a biogas storage tank 11, and a biogas combustion device 12, which are connected in sequence. The sludge outlets of the air flotation device 2, the anaerobic sedimentation tank 4, and the built-in MBR tank 6 are connected to a sludge thickening tank 13, which is connected to a sludge dewatering machine 14.

[0021] The bamboo product cooking wastewater of this utility model has the characteristics of high organic acid concentration, low pH (pH is about 3-4), high suspended solids concentration (SS5000-10000 mg / L), high COD (10,000-100,000 mg / L), and high chroma.

[0022] The pH regulating tank 1 of the utility model receives bamboo product cooking wastewater generated in the production workshop, and adds sodium hydroxide solution to the pH regulating tank 1 through the configured sodium hydroxide dosing device to adjust the pH of the wastewater to a range of 7-8. At the same time, a mixing stirrer is equipped to mix the wastewater to avoid precipitation of suspended matter; wherein, the sodium hydroxide dosing device includes a dosing tank and a drug delivery pipe connecting the dosing tank and the drug inlet of the pH regulating tank, and a valve is provided on the drug delivery pipe.

[0023] After pH adjustment, the wastewater is pumped into flotation unit 2, a dissolved air flotation tank, preferably a shallow one, to improve suspended solids removal efficiency and save floor space. The front end of the tank is equipped with a coagulation and flocculation mixing tank, which is equipped with a coagulation dosing device. The coagulation dosing device and the flocculation dosing device are similar in structure to the sodium hydroxide dosing device and are not described in detail here. By adding flocculants PAC and PAM, fine suspended particles are agglomerated, and the dissolved air causes the sludge to float upward, achieving mud-water separation and removing most of the suspended particles in the cooking wastewater.

[0024] After the suspended solids have been reduced by flotation, the wastewater is lifted by a lift pump and enters the EGSB anaerobic reactor 3. The cooking wastewater has a high organic acid concentration, good biodegradability, and a high suspended solids concentration, making it suitable for treatment by the EGSB anaerobic reactor 3 to remove most of the organic matter in the wastewater. Among them, the EGSB anaerobic reactor 3 is a conventional device in the form of a tank, including a mixing zone, a sludge bulking zone, a sedimentation zone, and a separation zone. It is equipped with an anaerobic water distributor, a hydraulic circulation system, a three-phase separation system, etc. The anaerobic water distributor adopts a single-tube spray full-coverage water distribution method. The hydraulic circulation system is equipped with a circulation pump. Through forced hydraulic internal circulation, the effluent and raw water are evenly mixed. The three-phase separator adopts a two-stage two-phase separation device, which first performs gas-liquid separation and then solid-liquid separation to reduce the suspended solids in the effluent. Because it is a conventional device, it will not be elaborated on here. Wastewater enters the tank through the anaerobic water distributor. The anaerobic effluent circulating water mixes with the influent and then evenly mixes with the anaerobic sludge in the reactor. The pH of the anaerobic reaction is controlled at 6.5-7.5, and the water temperature is controlled at 33-38°C. After entering the tank, the cooking wastewater passes upward through the sludge bed, undergoing a biological reaction with anaerobic bacteria, and then passes through a three-phase separator to separate the gas, solid, and liquid.

[0025] The biogas separated by the three-phase separator in the EGSB anaerobic reactor 3 is collected at the top of the tank body, desulfurized by the biogas desulfurization device 10, and then enters the biogas storage tank 11. It is then burned by the biogas combustion device 12 to achieve biogas resource recovery. The desulfurization process adopted by the biogas desulfurization device 10 is conventional dry desulfurization, wet desulfurization or biological desulfurization.

[0026] The effluent from the EGSB anaerobic reactor 3 enters the anaerobic sedimentation tank 4 to further precipitate the sludge carried by the anaerobic effluent, thereby reducing the amount of sludge entering the AOAO tank 5.

[0027] AOAO Tank 5 is divided into a primary A tank, a primary O tank, and secondary A tanks and secondary O tanks. Both the primary A tank and the secondary A tank are equipped with submersible flow propellers to thoroughly mix the wastewater. Both the primary O tank and the secondary O tank are equipped with liftable aerators, blowers, and internal recirculation pumps. This two-stage AO system achieves alternating nitrification and denitrification, improving reaction efficiency and reducing recirculation energy consumption. This allows for rapid maintenance and replacement of aerators without interruption. Dissolved oxygen levels in the primary A tank and the secondary A tank are controlled at 0-0.5 mg / L, and in the primary O tank and the secondary O tank at 2-4 mg / L, ensuring the removal of total nitrogen, COD, and total phosphorus.

[0028] The effluent from the AOAO pool 5 enters the built-in MBR pool 6, where the biochemical sludge is intercepted by the MBR membrane to reduce the SS and total phosphorus in the effluent. The built-in MBR pool 6 includes a curtain-type MBR membrane and an aeration device, and is also equipped with a water production self-priming pump, a backwash water pump and air pump, a sludge pump, an alkali washing device, a sodium hypochlorite cleaning device, etc., which is an existing conventional structure.

[0029] The effluent from the internal MBR tank 6 enters the intermediate tank 7 and is then elevated to the ozone contact oxidation tank 8. Because bamboo product cooking wastewater has a high chroma, even after biochemical treatment, it requires further treatment to reduce the chroma. The ozone contact oxidation tank 8 is equipped with an ozone generator and an ozone release device, utilizing ozone's strong oxidizing properties to further remove COD and chroma from the biochemical effluent.

[0030] The effluent from the ozone contact oxidation tank 8 is pumped into the biological denitrification tank 9, which is equipped with a filter layer, aeration system, and dissolved oxygen control system. The cooking wastewater contains a high level of total nitrogen. If two-stage AO biochemical denitrification fails to meet discharge requirements, further removal of total nitrogen is required. The biological denitrification tank achieves efficient total nitrogen removal by controlling dissolved oxygen and utilizing the anoxic microorganisms in the filter media. The wastewater after biological denitrification enters the effluent tank and is discharged when it meets discharge standards.

[0031] The sludge generated by the flotation unit 2, anaerobic sedimentation tank 4, and built-in MBR tank 6 is pumped to the sludge thickening tank 13, where it is then dehydrated by the sludge dewatering machine 14 before being transported for disposal. The sludge dewatering machine 14 is preferably a screw press dewatering machine, which reduces the moisture content of the dehydrated sludge to below 85%.

[0032] Taking the treatment of bamboo product cooking wastewater in a certain area of ​​Zhejiang as an example, the inlet and outlet water indicators of each stage of the bamboo product cooking wastewater treated by the treatment device of the utility model are shown in Table 1.

[0033] Table 1

[0034]

[0035] Note: The discharge requirements are: Class A standard in Table 1 of the "Water Quality Standard for Wastewater Discharge into Urban Sewers" (GB / T 31962-2015), and COD is the standard value accepted by the downstream sewage treatment plant.

[0036] The specific processing technology is:

[0037] S1. The COD of bamboo product cooking wastewater is 30,000 mg / L, SS is about 5,500 mg / L, and pH is about 3-4.

[0038] S2. After the pH is adjusted to 7-8 in the pH adjustment tank, the wastewater first enters the shallow dissolved air flotation tank, where most of the suspended particles and part of the COD are removed. The COD of the flotation effluent is about 22500 mg / L, and the SS is reduced to about 1375 mg / L.

[0039] S3. After flotation treatment, the effluent enters the EGSB anaerobic reactor, where the anaerobic microorganisms remove most of the organic matter and reduce the COD to about 3375 mg / L. The anaerobic COD removal rate can reach more than 85%.

[0040] The effluent from the S4 and EGSB anaerobic reactors enters the anaerobic sedimentation tank to further precipitate the sludge carried by the anaerobic effluent and reduce the amount of sludge entering the AOAO tank.

[0041] S5. The effluent from the anaerobic sedimentation tank enters the AOAO tank, where the biodegradable pollutants in the wastewater are further removed through alternating anoxic and aerobic biological action. The biochemical sludge is intercepted by the built-in MBR tank, and the COD of the biochemical effluent is controlled at around 500 mg / L.

[0042] S6. The effluent from the built-in MBR pool is temporarily stored in the intermediate water pool and then elevated to the ozone contact oxidation pool. Through the strong decolorization and COD removal capabilities of ozone, the color and COD of the biochemical effluent are further oxidized and removed, and the COD is reduced to below 450 mg / L.

[0043] S7. The effluent from the ozone contact oxidation tank enters the biological denitrification tank, which further reduces the COD and total nitrogen in the effluent. The biological denitrification tank serves as a guarantee unit to ensure that the COD and total nitrogen in the effluent meet the standards.

[0044] The advantages of the utility model are:

[0045] The utility model realizes multi-stage enhanced treatment of high-concentration bamboo product cooking wastewater through pretreatment, anaerobic biochemical treatment, two-stage biochemical enhanced treatment and ozone advanced oxidation + high-efficiency biological denitrification deep treatment, reduces the concentration of pollutants such as COD, meets the requirements of pipe collection or discharge to downstream sewage treatment plants, reduces pollution emissions, maintains ecological environmental safety, and has good social benefits; and the various devices adopted in the utility model can only make the water meet the discharge requirements after being combined and used in a specific order.

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Those skilled in the art will readily appreciate that the present invention is susceptible to various modifications and variations. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present invention shall be included within the scope of protection of the present invention.

Claims

1. A bamboo product cooking wastewater treatment system, characterized in that: include: Along the treatment flow of bamboo product cooking wastewater, a pH adjustment tank, an air flotation device, an EGSB anaerobic reactor, an anaerobic sedimentation tank, an AOAO tank, a built-in MBR tank, an intermediate water tank, an ozone contact oxidation tank and a biological denitrification tank are arranged in sequence; The exhaust port of the EGSB anaerobic reactor is provided with a biogas desulfurization device, a biogas storage tank and a biogas combustion device which are connected in sequence; The sludge outlets of the air flotation device, the anaerobic sedimentation tank and the built-in MBR tank are connected to the sludge concentration tank, and the sludge concentration tank is connected to the sludge dewatering machine.

2. The bamboo product cooking wastewater treatment system according to claim 1, characterized in that: The pH adjustment tank is equipped with a sodium hydroxide dosing device for adding sodium hydroxide solution into the pH adjustment tank to adjust the pH of the wastewater to 7-8; the pH adjustment tank is equipped with an agitator for preventing suspended particles from settling.

3. The bamboo product cooking wastewater treatment system according to claim 1, characterized in that: The flotation device adopts a dissolved air flotation tank, the front end of which is equipped with a coagulation stirring tank and a flocculation stirring tank, the coagulation stirring tank is equipped with a coagulation dosing device, and the flocculation stirring tank is equipped with a flocculation dosing device.

4. The bamboo product cooking wastewater treatment system according to claim 1, characterized in that: The AOAO pool is divided into a primary A pool, a primary O pool, a secondary A pool, and a secondary O pool; both the primary A pool and the secondary A pool are provided with a submersible flow propeller, and both the primary O pool and the secondary O pool are provided with a liftable aerator.

5. The bamboo product cooking wastewater treatment system according to claim 1, characterized in that: The EGSB anaerobic reactor includes a mixing zone, a sludge bulking zone, a sedimentation zone and a separation zone, and is equipped with an anaerobic water distributor, a hydraulic circulation system and a three-phase separation system. The anaerobic water distributor adopts a single-tube injection full-coverage water distribution method, and the hydraulic circulation system is equipped with a circulation pump. Through forced hydraulic internal circulation, the effluent and raw water are evenly mixed; the three-phase separation system adopts a two-stage two-phase separation device to first perform gas-liquid separation and then solid-liquid separation.

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