Food wastewater treatment system

Abstract

The utility model relates to a food wastewater treatment system, which comprises a flocculation sedimentation tank, an anoxic tank, an anaerobic tank, an aerobic tank and a filter tank which are sequentially connected through a pipeline, the water inlet end of the flocculation sedimentation tank is connected with a food wastewater discharge pipe, and the water outlet end of the filter tank is connected with a discharge port; and the mixed liquid outlet end of the aerobic tank is communicated with the anoxic tank through a pipeline. According to the system disclosed by the utility model, the flocculation sedimentation tank, the anoxic tank, the anaerobic tank, the aerobic tank and the filter tank are combined, so that good treatment efficiency and effect on organic matters in wastewater can be ensured. An anoxic tank, an anaerobic tank and an aerobic tank are sequentially connected, a large amount of nitrate and nitrite in the aerobic tank flow back to the anoxic tank from a mixed liquid outlet end, and wastewater in the anoxic tank is not treated by the anaerobic tank, so that the concentration of organic matters in the wastewater is high, a sufficient carbon source can be provided for denitrification reaction, and the denitrification function of the system is further enhanced.

Description

Technical Field

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

[0002] For food wastewater with high organic matter and high nitrogen, the traditional treatment process generally adopts the process system of oil separation sedimentation tank + anaerobic + anoxic + aerobic + sedimentation tank, but these process systems basically adopt the A2 / O process path (i.e. anaerobic-anoxic-aerobic process flow path). The anaerobic process can remove a large amount of organic matter and suspended solids in the wastewater, reduce the organic load of the combined aerobic process, and reduce the aerobic sludge production accordingly. The reaction volume of the whole process is much smaller; the anaerobic process as a pre-treatment process can play a balancing role, reduce the fluctuation of the subsequent aerobic process load, and greatly reduce the oxygen demand of the aerobic process and make it more stable, which saves energy and facilitates the actual operation in industry. The anaerobic process as a pre-treatment process can significantly improve the biodegradability of the wastewater and make the wastewater more smoothly undergo the aerobic biological treatment process. The anoxic tank creates an oxygen-deficient environment, refluxes a large amount of nitrates and nitrites in the aerobic tank through internal circulation, and uses the organic matter in the tank as a carbon source for denitrification and phosphorus removal reactions.

[0003] Because the effluent from the aerobic pool flows back to the anoxic pool, the nitrate nitrogen generated in the aerobic pool is removed by denitrification, and the removal of ammonia nitrogen and total nitrogen is very effective. However, since the denitrification reaction needs to be completed under the condition of sufficient carbon source, the organic matter in the sewage has been largely degraded after the front-end anaerobic process, so the denitrification will be affected to a certain extent, resulting in less than ideal denitrification effect. Utility Model Content

[0004] The utility model aims to provide a food wastewater treatment system, which has a good removal effect on organic matter and nitrogen in wastewater.

[0005] To achieve the above-mentioned purpose, the utility model discloses a food wastewater treatment system, which includes a flocculation sedimentation tank, an anoxic tank, an anaerobic tank, an aerobic tank and a filtration tank which are connected in sequence through pipelines, the water inlet end of the flocculation sedimentation tank is connected to a food wastewater discharge pipe, the water outlet end of the filtration tank is connected to a discharge port; the mixed liquor water outlet end of the aerobic tank is connected to the anoxic tank through a pipeline.

[0006] Preferably, the flocculation sedimentation tank is an electrochemical flocculation sedimentation tank.

[0007] Preferably, the anaerobic tank is a baffled anaerobic tank.

[0008] Preferably, the aerobic tank is an aerobic activated sludge tank.

[0009] Preferably, the filtration tank is an MBR tank; the MBR tank is provided with a first sludge return pipe for returning sludge to the aerobic tank.

[0010] Preferably, it further comprises an anaerobic sedimentation tank disposed between the anaerobic tank and the aerobic tank; the anaerobic sedimentation tank is provided with a second sludge return pipe for returning sludge to the anaerobic tank.

[0011] Preferably, the anaerobic sedimentation tank is provided with a mud discharge pipe.

[0012] Preferably, a sludge pool is further included, and the sludge discharge pipes of the flocculation sedimentation tank, the aerobic tank and the filtration tank are all connected to the sludge pool.

[0013] Preferably, it also includes a filter press for making the sludge in the sludge tank into a mud cake, and the filtrate outlet pipe of the filter press is connected to the anoxic tank or the flocculation sedimentation tank.

[0014] Preferably, it also includes a comprehensive regulating tank arranged between the flocculation sedimentation tank and the anoxic tank.

[0015] The utility model has the following beneficial effects:

[0016] 1. The utility model system can ensure good treatment efficiency and effect of organic matter in wastewater by combining flocculation sedimentation tank, anoxic tank, anaerobic tank, aerobic tank and filtration tank. The anoxic tank, anaerobic tank and aerobic tank are connected in sequence. A large amount of nitrate and nitrite in the aerobic tank flows back to the anoxic tank from the outlet of the mixed liquid. The wastewater in the anoxic tank has a high concentration of organic matter because it has not been treated in the anaerobic tank. It can provide sufficient carbon source for denitrification reaction, thereby strengthening the denitrification function of the system.

[0017] 2. The flocculation sedimentation tank is an electrochemical flocculation sedimentation tank, which opens the ring and breaks the chain of organic macromolecules while removing the precipitate, degrading substances that are not conducive to biodegradation into easily biodegradable substances, thereby improving the biodegradability of organic matter, reducing the subsequent sludge cultivation cycle, reducing the operating costs of the sewage plant, and increasing the stability of the effluent.

[0018] 3. By designing the filter pool as an MBR pool, the system footprint can be effectively reduced. High-concentration sludge can be cultivated in the MBR pool, and the sludge age can be very long, thereby greatly improving the degradation efficiency of organic matter. Moreover, the MBR can completely intercept the sludge, suspended matter and microorganisms in the pool. This process greatly improves the efficiency of solid-liquid separation. The suspended matter and turbidity of the effluent are almost zero, and it can be directly reused, realizing sewage resource utilization and optimizing corporate profits and losses. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the utility model.

[0020] Note: The solid line with arrows in the figure represents the path of sewage, and the dotted line with arrows represents the path of sludge. DETAILED DESCRIPTION

[0021] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0022] like Figure 1 As shown, the utility model discloses a food wastewater treatment system, which includes a flocculation sedimentation tank, a comprehensive regulating tank, an anoxic tank, an anaerobic tank, an anaerobic sedimentation tank, an aerobic tank and a filter tank connected in sequence through pipelines, the water inlet end of the flocculation sedimentation tank is connected to the food wastewater discharge pipe, and the water outlet end of the filter tank is connected to the discharge port. The mixed liquid outlet end of the aerobic tank is connected to the anoxic tank through a pipeline. The filter tank is an MBR tank, which is provided with a first mud return pipe for returning sludge to the aerobic tank. The anaerobic sedimentation tank is provided with a second mud return pipe for returning sludge to the anaerobic tank. In addition, the system is also provided with a sludge tank for collecting sludge, and the mud discharge pipes of the flocculation sedimentation tank, the anaerobic sedimentation tank, the aerobic tank and the filter tank are all connected to the sludge tank, and a filter press is provided in the sludge tank for making the sludge therein into mud cakes, and the sewage filtered out during the filter pressing process is returned to the comprehensive regulating tank.

[0023] The flocculation sedimentation tank is an electrochemical flocculation sedimentation tank, which mainly adjusts the pH value by online control of the acid-base pump, and then quantitatively adds mixing and flocculants. The colloidal particles and tiny suspended matter in the water are flocculated and precipitated, thereby separating the mud and water. The sludge is discharged to the sludge tank through the pipeline, and the supernatant enters the electrochemical advanced oxidation device. The macromolecular organic matter in the water can be opened and broken, thereby being converted into small molecular organic matter to improve the biodegradability of subsequent treatment. Some volatile organic matter can be directly separated by aeration and volatilization in the device.

[0024] The wastewater flowing out of the flocculation sedimentation tank enters the comprehensive regulating tank, and the high-organic and high-nitrogen wastewater is homogenized and equalized through the internal reflux device, and appropriate amounts of nutrient agents are added to adjust the ratio of carbon source / nitrogen source / phosphorus source and the adaptability of the biochemical system inlet water.

[0025] The anoxic pool creates an anoxic environment by controlling the blower and valve to input a small amount of oxygen. A large amount of nitrate and nitrite in the aerobic pool is returned through internal circulation (i.e., from the mixed liquid outlet of the aerobic pool). The denitrifying bacteria in the pool use the undecomposed carbon-containing organic matter in the sewage as a carbon source, and carry out denitrification and denitrification reactions in the pool, reducing nitrate and nitrite to N2 and releasing them. The anoxic pool pre-placement gives priority to meeting the denitrification carbon source demand, strengthening the denitrification function of the treatment system. The anoxic pool has a hydrolysis reaction, which removes some organic matter while denitrifying, improving biodegradability.

[0026] The anaerobic tank is a baffled anaerobic tank. Several vertical guide plates are set in the baffled anaerobic tank to divide the tank body into several reaction chambers in series. Each reaction chamber can be regarded as a relatively independent upflow sludge bed system (UASB for short). After the wastewater enters the reactor, it moves along the guide plate up and down, and passes through the sludge bed of each reaction chamber in turn. The organic matrix in the wastewater is removed by sufficient contact with the microorganisms. The sludge precipitated on the inclined wall slides back to the anaerobic reaction area along the inclined wall, so that a large amount of sludge accumulates in the reaction area. The treated effluent separated from the sludge overflows from the upper part of the overflow weir of the sedimentation area. In the early stage of sludge cultivation, the residual sludge and eliminated sludge of the anaerobic tank enter the anaerobic sedimentation tank, which is convenient for discharge from the system to reduce the harm to the system. In the later stage, the sludge can be returned to the anaerobic tank through the anaerobic sedimentation tank to ensure that the COD removal efficiency is further improved.

[0027] The aerobic tank is an activated sludge aerobic tank. The activated sludge process is the most widely used aerobic biochemical treatment technology for wastewater. It is mainly composed of an aeration tank, an aeration system, and a sludge return system. The aerobic activated sludge tank continuously mixes sewage and various microbial communities under the condition of forced aeration and oxygenation to form activated sludge. The biological coagulation, adsorption and oxidation of activated sludge are used to decompose and remove organic pollutants in sewage, and absorb and remove elements such as nitrogen and phosphorus. After being treated in the aerobic activated sludge tank, the sewage flows into the filter tank by gravity.

[0028] The filtration tank is an MBR tank. MBR is a sewage treatment process that combines membrane filtration high-efficiency solid-liquid separation technology with microbial degradation technology. The high-efficiency separation effect of the membrane is used in the system, and the treated water is extremely clear, the suspended solids and turbidity are close to zero, and bacteria and viruses are greatly removed. At the same time, membrane separation also allows the microorganisms to be completely intercepted in the bioreactor, so that a high concentration of microorganisms can be maintained in the system, which not only improves the overall removal efficiency of the reaction device for pollutants and ensures good effluent water quality, but also the reactor has good adaptability to various changes in the influent load (water quality and water volume), is resistant to shock loads, and can stably obtain high-quality effluent water quality, which can ensure that the effluent can stably meet the standards. In order to avoid the influence of excessive solid concentration in the pool on the effluent efficiency of MBR membrane filtration, the sludge in the pool is regularly discharged to the sludge pool in an appropriate amount.

[0029] The electrochemical flocculation precipitation at the front end converts high-concentration difficult-to-degrade organic matter into easily degradable matter. The subsequent biochemical treatment debugging and sludge cultivation can be completed faster and simpler. The COD removal of food wastewater targeted by the utility model is not difficult, but the difficulty lies in the treatment of ammonia nitrogen. Therefore, coordinating with the anoxic tank in front can ensure that the overall water discharge efficiency is more stable and efficient.

[0030] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily thought of by any technician familiar with the technical field within the technical scope disclosed in the present invention should be included in the protection scope of the present invention.

Claims

1. A food wastewater treatment system, characterized in that: It comprises a flocculation sedimentation tank, an anoxic tank, an anaerobic tank, an aerobic tank and a filtering tank which are connected in sequence through pipelines. The water inlet of the flocculation sedimentation tank is connected to a food wastewater discharge pipe, and the water outlet of the filtering tank is connected to a discharge port; the mixed liquid water outlet of the aerobic tank is connected to the anoxic tank through a pipeline.

2. The food wastewater treatment system according to claim 1, characterized in that: The flocculation sedimentation tank is an electrochemical flocculation sedimentation tank.

3. The food wastewater treatment system according to claim 1, characterized in that: The anaerobic tank is a baffled anaerobic tank.

4. The food wastewater treatment system according to claim 1, characterized in that: The aerobic tank is an aerobic activated sludge tank.

5. The food wastewater treatment system according to claim 1, characterized in that: The filtering tank is an MBR tank; the MBR tank is provided with a first sludge return pipe for returning sludge to the aerobic tank.

6. The food wastewater treatment system according to claim 1, characterized in that: It also includes an anaerobic sedimentation tank arranged between the anaerobic tank and the aerobic tank; the anaerobic sedimentation tank is provided with a second mud return pipe for returning mud to the anaerobic tank.

7. The food wastewater treatment system according to claim 6, characterized in that: The anaerobic sedimentation tank is provided with a mud discharge pipe.

8. The food wastewater treatment system according to claim 1, characterized in that: It also includes a sludge pool, and the sludge discharge pipes of the flocculation sedimentation tank, the aerobic tank and the filtration tank are all connected to the sludge pool.

9. The food wastewater treatment system according to claim 8, characterized in that: It also includes a filter press for making mud cakes from the sludge in the sludge tank, and the filtrate outlet pipeline of the filter press is connected to the anoxic tank or the flocculation sedimentation tank.

10. The food wastewater treatment system according to claim 1, characterized in that: It also includes a comprehensive regulating tank arranged between the flocculation sedimentation tank and the anoxic tank.

Images