Advanced treatment method and equipment for gelatin production sewage

Abstract

The invention provides an advanced treatment method and equipment for gelatin production wastewater, which can improve the treatment efficiency of gelatin wastewater, reduce the investment of chemicals, activated sludge, construction cost and the like, avoid equipment blockage, ensure zero discharge of the gelatin production wastewater, and meet the wastewater treatment requirements of large gelatin production plants. Comprising the following steps: pre-treating wastewater, introducing the wastewater into a comprehensive wastewater collecting tank, and pumping a mixed solution into a pre-aeration regulating tank through a second draw-off pump; supernate in the pre-aeration regulating tank is pumped into a static mixer, and the mixed sewage sequentially passes through a folded plate flocculation tank, a horizontal flow sedimentation tank and an inclined tube sedimentation tank; supernate in the inclined tube sedimentation tank is sequentially guided into an AO biochemical tank and a V-shaped filter tank, primarily filtered water of the V-shaped filter tank enters a reflux tank, and backwashing water of the V-shaped filter tank enters a drainage tank; bottom mud of the preliminary sedimentation tank, the folded plate flocculation tank, the horizontal flow sedimentation tank, the inclined tube sedimentation tank, the AO biochemical tank and the drainage tank is discharged into the mud discharge tank.

Description

Technical Field

[0001] The invention relates to the field of gelatin wastewater treatment, and in particular to a method for deep treatment of gelatin production wastewater. Background Art

[0002] The wastewater generated during the gelatin production process contains a large amount of inorganic salts and organic matter. If it is discharged at will, it will cause great pollution to the environment and needs to be treated before it can be discharged.

[0003] In the existing gelatin production wastewater treatment process, for example, a gelatin production workshop wastewater treatment and reuse process with patent application number CN202211150931.0, the treatment is carried out through the following steps: Step 1: raw water collection; Step 2: filter cloth filtration; Step 3: ceramic membrane treatment; Step 4: ultrafiltration treatment. However, the Ca content of gelatin wastewater is 2+ The concentration is high. If ceramic membrane and ultrafiltration methods are used for treatment, ceramic membrane and ultrafiltration equipment will be blocked. In addition, a large amount of wastewater is generated during the gelatin production process. These wastewaters have the characteristics of large water volume, good biodegradability, high concentration, and large water quality fluctuations. The daily wastewater discharge of large gelatin production plants is 3,000-5,000 cubic meters. If such a large amount of wastewater such as calcium hydrogen phosphate is input, it will cause serious blockage if membrane treatment is used, and it will condense on the equipment and is not easy to clean. Summary of the invention

[0004] The purpose of the present invention is to provide a method and equipment for deep treatment of gelatin production wastewater, which can improve the treatment efficiency of gelatin wastewater, reduce the investment in chemicals, activated sludge, construction costs, etc., avoid equipment clogging, ensure zero discharge of gelatin production wastewater, and can be suitable for the wastewater treatment needs of large-scale gelatin production plants.

[0005] The embodiment of the present invention is achieved as follows:

[0006] A method for deep treatment of gelatin production wastewater, comprising the following steps:

[0007] The first-class workshop wastewater is sequentially introduced into the gray water collection tank after impurities are removed through the first grille. After air is introduced into the gray water collection tank, the mixed liquid is extracted into the pre-sedimentation tank through the first extraction pump;

[0008] After the Class II workshop wastewater is removed of impurities through the second grille in turn, it is introduced into the comprehensive wastewater collection tank. After air is introduced into the comprehensive wastewater collection tank, the mixed liquid is extracted into the pre-aeration regulating tank through the second extraction pump; the supernatant in the pre-sedimentation tank flows into the comprehensive wastewater collection tank;

[0009] The supernatant in the pre-aeration regulating tank is extracted and enters the static mixer, in which a coagulant is provided. The mixed sewage passes through the folded plate flocculation tank, the horizontal flow sedimentation tank and the inclined tube sedimentation tank in sequence;

[0010] The supernatant in the inclined tube sedimentation tank is sequentially introduced into the AO biochemical tank and the V-type filter tank, the primary filtered water of the V-type filter tank enters the return tank, and the backwash water of the V-type filter tank enters the drainage tank; the supernatant in the return tank and the drainage tank flows back to the first grid or the second grid;

[0011] The sludge from the pre-sedimentation tank, folded plate flocculation tank, horizontal flow sedimentation tank, inclined tube sedimentation tank, AO biochemical tank and drainage tank is discharged into the sludge discharge tank. The supernatant of the sludge discharge tank flows back to the first grid or the second grid. The sludge in the sludge discharge tank enters the sludge balance tank after concentration and is transported out after dehydration.

[0012] The AO biochemical tank includes a hydrolysis tank, an anoxic tank, an aerobic tank and a secondary sedimentation tank which are connected in sequence. The mixed liquor of the aerobic tank flows back to the anoxic tank; the sludge of the secondary sedimentation tank flows back to the hydrolysis tank; the supernatant of the secondary sedimentation tank is introduced into the static mixer through the third extraction pump, and the residual sludge of the secondary sedimentation tank enters the sludge discharge tank.

[0013] The folded plate flocculation tank is equipped with three flocculation zones, each of which is equipped with a folded plate combination consisting of 90° relative folded plates and 90° parallel folded plates. The residence time of the first flocculation zone is 4 minutes, the peak velocity is 0.3 m / s, the valley velocity is 0.07 m / s, and the G value is 94.5S -1 The residence time of the second flocculation zone is 5 min, the peak velocity is 0.2 m / s, and the G value is 58.4 S -1 The residence time in the third flocculation zone is 7 min, the peak velocity is 0.1 m / s, and the G value is 22.1 S -1 .

[0014] Category I workshop wastewater includes acid soaking workshop wastewater, phosphate-calcium workshop wastewater, and liming workshop wastewater.

[0015] Coagulant polyaluminium chloride and flocculant polyacrylamide are added into the static mixer.

[0016] The pre-sedimentation tank and the horizontal flow sedimentation tank are equipped with a traveling sludge suction machine. A sludge concentration meter is installed on the branch pipe of the traveling sludge suction machine. When the sludge concentration reaches the set condition, the pneumatic valve is opened to discharge the sludge, and the sludge discharge vehicle continues to move forward. When it is 2m away from the flocculation tank, the pneumatic forced sludge discharge is turned on. When the scraper is retracted, the pneumatic valve is closed.

[0017] The pre-aeration regulating tank is injected with ozone and air through a micro-nano bubble generator, and the content ratio of ozone to air is 7-7.5:2.5-3.

[0018] The medicine inlet pipes of the static mixer and the folded plate flocculation tank are provided with heating steam pipes.

[0019] A bidirectional separation cyclone reaction sedimentation device is provided in the pre-aeration regulating tank.

[0020] The embodiment of the present invention also provides a gelatin production wastewater deep treatment equipment, which includes:

[0021] A first grid, a grey water collection tank and a pre-sedimentation tank connected in sequence;

[0022] The second grid, the comprehensive wastewater collection tank, and the pre-aeration regulating tank are connected in sequence; the supernatant of the pre-sedimentation tank is connected to the comprehensive wastewater collection tank through a pipeline;

[0023] The supernatant of the pre-aeration regulating tank is connected to the static mixer, the folded plate flocculation tank, the advection sedimentation tank and the inclined tube sedimentation tank in sequence through pipelines;

[0024] The supernatant of the inclined tube sedimentation tank is connected to the AO biochemical tank and the V-type filter tank in sequence through pipelines; the primary filtered water of the V-type filter tank is connected to the return tank through pipelines, and the backwash water of the V-type filter tank is connected to the drainage tank through pipelines; the supernatant of the return tank and the drainage tank is connected to the water inlet of the first grid or the second grid through pipelines;

[0025] The pre-sedimentation tank, folded plate flocculation tank, horizontal flow sedimentation tank, inclined tube sedimentation tank, AO biochemical tank and drainage tank are scraped off the bottom sludge through the sludge scraping equipment and connected to the sludge discharge tank through the sludge discharge pump; the supernatant of the sludge discharge tank is connected to the water inlet of the first grid or the second grid through a pipeline; the sludge in the sludge discharge tank enters the sludge balance tank after concentration and is transported out after dehydration.

[0026] The beneficial effects of the embodiments of the present invention are:

[0027] In the present invention, the gelatin production wastewater is pre-aerated after pretreatment. During the pre-aeration process, air and ozone are used for aeration treatment. On the basis of reducing the pollutants in the AO biochemical pool, a part of the organic matter in the gelatin wastewater cannot be oxidized. After being catalyzed by H2O2 and oxidized by ozone, it is converted into organic matter that can be chemically oxidized, and then adsorbed and absorbed by the activated sludge in the AO biochemical pool, thereby improving the removal effect of COD, and is significantly higher than the biochemical effluent of other processes;

[0028] The supernatant after pre-aeration treatment enters the static mixer, and then passes through the folded plate flocculation tank, the horizontal flow sedimentation tank and the inclined tube sedimentation tank in turn. The tubular static mixer shortens the mixing time. At the same time, a heating steam pipe is provided on the tubular static mixer, which shortens the mechanical mixing time. The DN15 steam pipe heating means that each pipe and the steam heating pipe are placed close together for insulation, which can reduce the risk of the reagent clogging the pipe due to temperature drop and reduced solubility;

[0029] Then, the folded plate flocculation tank, horizontal flow sedimentation tank and inclined tube sedimentation tank are designed in turn, which can carry out flocculation and multiple sedimentation to remove impurities before the wastewater enters the AO biochemical tank, shorten the action time of the AO biochemical tank, thereby reducing the amount of activated sludge, etc. and saving wastewater treatment costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0031] Figure 1 This is a flow chart of a method for deep treatment of gelatin production wastewater according to an embodiment of the present invention;

[0032] Figure 2 It is a process flow chart of a gelatin production wastewater deep treatment equipment according to an embodiment of the present invention;

[0033] Figure 3 This is a process flow chart of the AO biochemical pool according to an embodiment of the present invention;

[0034] Figure 4 It is a schematic structural diagram of a combined tank of a folded plate flocculation tank, a horizontal flow sedimentation tank and an inclined tube sedimentation tank according to an embodiment of the present invention;

[0035] Figure 5 This is a sludge treatment flow chart for deep treatment of gelatin production wastewater in an embodiment of the present invention.

[0036] Icons: first screen 1; gray water collection tank 2; pre-sedimentation tank 3; second screen 4; integrated wastewater collection tank 5; pre-aeration regulating tank 6; static mixer 7; folded plate flocculation tank 8; horizontal flow sedimentation tank 9; inclined tube sedimentation tank 10; heated steam pipe 11; AO biochemical tank 12; hydrolysis tank 121; anoxic tank 122; aerobic tank 123; secondary sedimentation tank 124; V-type filter 13; reflow tank 14; drainage tank 15; sludge discharge tank 16; sludge balance tank 17. DETAILED DESCRIPTION

[0037] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, 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 described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0038] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0039] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, further definition and explanation thereof is not required in subsequent drawings.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inside", "outside", etc. indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, or the positions or positional relationships in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", "third", etc. are only used to distinguish the description, and cannot be understood as indicating or implying relative importance.

[0041] In addition, the terms "horizontal", "vertical", "overhanging" and the like do not mean that the components are required to be absolutely horizontal or overhanging, but can be slightly tilted. For example, "horizontal" only means that its direction is more horizontal than "vertical", and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0042] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "set", "install", "connect", and "connect" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0043] First embodiment

[0044] Bone gelatin is a fat-free, high-protein food extracted from bones. The wastewater generated in its production process mainly comes from defatting, pickling, liming, neutralization, gelatin making and calcium hydrogen phosphate production processes. The composition is complex and difficult to treat. The gelatin production capacity of gelatin production enterprises has reached 1,500 tons, and the daily wastewater treatment volume is 2,500-3,000 cubic meters. The main products include medicinal gelatin, edible gelatin and by-product feed-grade calcium hydrogen phosphate.

[0045] The present embodiment targets the gelatin production wastewater, which not only has a large amount of water, but also has a high concentration of organic matter and a high concentration of suspended matter. The organic matter in these wastewaters mainly includes proteins, polypeptides, amino acids, etc., which are dissolved or suspended in the wastewater during the production process, increasing the difficulty of wastewater treatment. In view of the difficulties existing in the existing wastewater treatment processes, a new method for deep treatment of gelatin production wastewater is designed, which can improve the treatment capacity and treatment efficiency of gelatin wastewater. Effective wastewater treatment can not only reduce environmental pollution, but also improve the quality of water used in the production process, and improve the quality and output of products. For example, by reusing treated wastewater, the demand for fresh water resources can be reduced and production costs can be reduced.

[0046] For details, see Figure 1-5 This embodiment provides a method for deep treatment of gelatin production wastewater, which comprises the following steps:

[0047] S11: The first type of workshop wastewater is sequentially introduced into the gray water collection tank 2 after impurities are removed through the first grid 1. After air is introduced into the gray water collection tank 2, the mixed liquid is extracted into the pre-sedimentation tank 3 through the first extraction pump.

[0048] Among them, the first type of workshop wastewater is the wastewater from the pickling workshop, the wastewater from the phosphate and calcium workshop, and the wastewater from the liming workshop. The wastewater generated by the pickling workshop, the phosphate and calcium workshop, and the liming workshop is transported by an open channel, and the coarse matter such as bone particles is removed by the screen, and then flows by gravity to the ash water collection tank 2. It should be noted that the collection tank is equipped with an aeration device to prevent sludge sedimentation. After that, the effluent is lifted to the pre-sedimentation tank 3 by a lifting pump, and most of the suspended matter such as lime is removed by sedimentation, and the clean water flows by gravity into the comprehensive wastewater collection tank.

[0049] S12: After the impurities in the Class II workshop wastewater are removed through the second grid 4 in turn, it is introduced into the comprehensive wastewater collection tank 5. After air is introduced into the comprehensive wastewater collection tank 5, the mixed liquid is extracted into the pre-aeration regulating tank 6 through the second extraction pump; the supernatant in the pre-sedimentation tank 3 flows into the comprehensive wastewater collection tank 5.

[0050] Among them, wastewater from the second-class workshops is all wastewater used in gelatin production except wastewater from the first-class workshops, such as degreasing workshops, rubber extraction workshops, etc. The wastewater generated by them is also transported by open channels, and the coarse matter such as bone particles is removed by the screen, and then flows to the comprehensive wastewater collection tank 5 by gravity. The wastewater from the two types of workshops after rough treatment by the screen is then concentrated in the comprehensive wastewater collection tank 5. Similarly, the comprehensive wastewater collection tank 5 is also equipped with an aeration device to prevent sludge precipitation by introducing air for aeration.

[0051] In this embodiment, the wastewater generated in the pickling section and the calcium hydrogen phosphate production section is acidic and mainly contains Cl - , Ca 2 +The wastewater from the liming process is alkaline and contains a large amount of organic matter such as Ca(OH)2, protein and amino acids. Excessive Cl- concentration has a certain inhibitory effect on biochemical treatment. The protein and amino acids contained in the wastewater also increase the difficulty of treating NH3-N in compliance with the emission standards. The wastewater has a high SS concentration, is easy to corrupt, and produces a large amount of sludge. The SS concentration per liter of wastewater can be as high as thousands of milligrams.

[0052] Therefore, in this embodiment, the mixed liquid is extracted into the pre-aeration regulating tank 6 through the second extraction pump, and ozone and air are injected into the pre-aeration regulating tank 6 through the micro-nano bubble generating device, and the content ratio of ozone and air is 7-7.5:2.5-3. The air and ozone enter the air source mixing pump through the pores, and micro-nano bubbles are generated by the method of pressurization and decompression and enter the flotation column to complete the flotation process. The separated oil and fat float on the liquid surface.

[0053] As the ozone concentration increases, the amount of hydroxyl radicals generated increases. In addition, ozone itself has a certain oxidizing ability, so the removal efficiency of pollutants in water increases accordingly. However, too high a concentration of ozone will cause a waste of resources and increase the cost of ozone tail gas treatment. Therefore, the ratio of ozone to air is 7-7.5:2.5-3.

[0054] The ozone conversion rate will increase with the increase of water temperature. The increase in the number of activated molecules will accelerate the chemical reaction rate, and the ozone utilization rate will increase accordingly. However, at the same ozone concentration, the increase in temperature will cause the stability of ozone to deteriorate and decompose, and its solubility in water will decrease instead. Therefore, when the temperature is further increased, although the activity of ozone molecules increases, its solubility decreases, resulting in a decrease in the amount of hydroxyl radicals generated, and the treatment effect becomes worse. The water temperature of the pre-aeration regulating tank 6 in this embodiment is controlled at 25-30°C.

[0055] At the same time, the micro-nano bubbles are injected with ozone to acidify the wastewater in the pre-aeration regulating tank 6. By adjusting the pH of the wastewater, the Zeta potential of the micro-nano bubbles can be effectively changed, thereby affecting the flotation effect and reducing the amount of sulfuric acid used in the later stage. Moreover, under acidic conditions, the oil removal effect of micro-nano bubbles is significantly better than that under alkaline conditions, thereby improving the pretreatment effect.

[0056] At the same time, a two-way separation cyclone reaction sedimentation device is provided in the pre-aeration regulating tank 6. The incoming water enters the inner cavity sedimentation separation zone tangentially through the water inlet pipe of the two-way separation cyclone reaction sedimentation device. The water flow fully reacts with the reagent in the inner cavity through the hydrocyclone. Due to the decrease in the incoming water pressure, the flocs after the reaction float to the water surface with the help of the dissolved gas released in the produced water and condense into scum, and at the same time help the grease to condense into scum. The water flows out from the bottom of the inner cylinder sedimentation separation zone to the surroundings and enters the clean water zone of the outer cavity. After the clean water separated by sedimentation passes through the inclined plate packing layer of the clean water zone from bottom to top, the flocs in the sewage are further intercepted. The clean water flows through the water collecting bell mouth and is collected and discharged through the outlet pipe. The outlet water enters the next treatment unit.

[0057] The two-way separation cyclone reaction sedimentation device is equipped with a negative pressure slag collecting device at the top of the tank cavity. The floating slag first enters the negative pressure slag collecting device and then is discharged from the tank through the slag discharge pipe. The floating oil brought by the previous process is collected by the oil collecting tank and then discharged from the tank through the oil collecting pipe. The sludge deposited at the bottom is regularly discharged from the tank through the sludge discharge device.

[0058] S2: The supernatant in the pre-aeration regulating tank 6 is extracted and enters the static mixer 7. A coagulant is provided in the static mixer 7. The mixed sewage passes through the folded plate flocculation tank 8, the horizontal flow sedimentation tank 9 and the inclined tube sedimentation tank 10 in sequence.

[0059] The effluent after catalytic ozone oxidation treatment is pumped into a static mixer to further remove residual organic matter and pollutants such as ammonia nitrogen in the water.

[0060] The coagulant polyaluminium chloride and the flocculant polyacrylamide are added into the static mixer 7, and after being mixed evenly, they are put into the folded plate flocculation tank 8 for reaction. This flocculation is used to remove oils and fats and other substances that are not easy to sink in the wastewater.

[0061] The method of multiple single channels in parallel is adopted, and three stages of flocculation are set in each channel. The construction is relatively simple and the precision is high, while ensuring the uniform water discharge of the folded flocculation tank. Each group of incoming water enters the 8 flow channels of the folded plate flocculation tank 8 through 8 water inlet holes. It can achieve multi-point water inlet and multi-point water outlet. The interconnecting pipe is pre-buried at the bottom of each channel. The material is PVC-U pipe with a small resistance coefficient, which can increase the flow rate in the pipe and reduce the possibility of blockage.

[0062] The flocculation time and GT value of the folded plate flocculation tank 8 are the key to the design and are important indicators of whether the reaction flocculation process is sufficient and complete. The folded plate flocculation tank 8 is equipped with three flocculation zones, each of which is equipped with a folded plate combination consisting of 90° relative folded plates and 90° parallel folded plates. The residence time of the first flocculation zone is 4 minutes, the peak velocity is 0.3m / s, the valley velocity is 0.07m / s, and the G value is 94.5S -1 The residence time of the second flocculation zone is 5 min, the peak velocity is 0.2 m / s, and the G value is 58.4 S -1The residence time in the third flocculation zone is 7 min, the peak velocity is 0.1 m / s, and the G value is 22.1 S -1 .

[0063] In this embodiment, each flocculation zone is provided with a folding plate combination composed of a 90° opposite folding plate and a 90° parallel folding plate. Under the same water depth condition, the larger the folding plate angle, the fewer turns the water flow makes. When the water flow flows vertically upward and downward along the 90° folding plate, the turning angle is large, that is, multiple turns are made, and the turbulent state required for flocculation is achieved, so that the energy loss is fully utilized, and the mixed solution of the source water and the flocculant achieves a good flocculation effect.

[0064] In the present embodiment, the static mixer 7 and the medicine inlet pipe of the folded plate flocculation tank 8 are provided with a heating steam pipe 11, which shortens the mechanical mixing time. The DN15 steam pipe heating means that each pipe and the steam heating pipe are placed close together for insulation, which can reduce the risk of the medicine being easily blocked by the pipe due to a drop in temperature and a decrease in solubility.

[0065] In this embodiment, a traveling sludge suction machine is provided for the pre-sedimentation tank 3 and the horizontal flow sedimentation tank 9 with a large sedimentation volume. A sludge concentration meter is provided on the branch pipe of the traveling sludge suction machine. When the sludge concentration reaches the set condition, the pneumatic valve is opened to discharge the sludge, and the sludge discharge vehicle continues to move forward. When it is 2m away from the flocculation tank, the pneumatic forced sludge discharge is turned on. When the scraper is retracted, the pneumatic valve is closed.

[0066] The lower part of both the horizontal flow sedimentation tank 9 and the inclined tube sedimentation tank 10 is provided with a drainage pipe, a gate is provided on the drainage pipe, and the drainage pipe is connected to the drain pipe at the bottom of the tank through a connecting pipe. When the tank needs to flush the inclined tube, it only needs to open the valve on the drainage pipe at the lower part of the inclined tube to drain the water; the drainage at this part will not affect the sludge system at the bottom of the tank.

[0067] S3: The supernatant in the inclined tube sedimentation tank 10 is sequentially introduced into the AO biochemical tank 12 and the V-type filter 13, the primary filtered water of the V-type filter 13 enters the reflow tank 14, and the backwash water of the V-type filter 13 enters the drainage tank 15; the supernatant in the reflow tank 14 and the drainage tank 15 flows back to the first grid 1 or the second grid 4.

[0068] The AO biochemical tank 12 includes a hydrolysis tank 121, an anoxic tank 122, an aerobic tank 123 and a secondary sedimentation tank 124 which are connected in sequence. The mixed liquid of the aerobic tank 123 flows back to the anoxic tank 122; the sludge of the secondary sedimentation tank 124 flows back to the hydrolysis tank 121; the supernatant of the secondary sedimentation tank 124 is introduced into the static mixer 7 through the third extraction pump, and the residual sludge of the secondary sedimentation tank 124 enters the sludge discharge tank 16.

[0069] It flows by gravity into the AO biochemical tank, and the macromolecular organic matter is hydrolyzed into small molecular organic matter in the hydrolysis tank 121 to improve the removal efficiency of organic matter. At the same time, organic nitrogen is converted into ammonia nitrogen through hydrolysis. In the subsequent anoxic tank 122 and aerobic tank 123, most of the dissolved organic pollutants are removed by the microbial action of the system's activated sludge, and denitrification is carried out through biological nitrification and denitrification. Submersible mixers are arranged in the hydrolysis tank 121 and the anoxic tank 122, and a lifting aerator is arranged in the aerobic tank 123. The mixed liquid is returned to the anoxic tank 122 through an internal reflux pump. After the mixed liquid in the aerobic tank 123 is precipitated in the secondary sedimentation tank 124, the effluent meets the discharge standards.

[0070] In this embodiment, high calcium, high phosphorus, high alkali and high protein are the main characteristics of gelatin wastewater. How to effectively treat and meet the discharge standards is an important problem faced by gelatin production enterprises. Gelatin wastewater has a high alkalinity and contains high concentrations of calcium, protein, fat and other organic matter. The anaerobic-aerobic two-step method is often used in actual treatment. During the anaerobic-aerobic treatment process, both anaerobic and aerobic reactors are open for operation. Under anaerobic conditions, large molecular refractory organic matter can be decomposed into more easily degradable small molecular organic matter through facultative bacterial hydrolysis, and insoluble organic matter can be decomposed into soluble organic matter, which improves the biodegradability of wastewater and creates favorable conditions for subsequent aerobic treatment. In the aerobic process, the assimilation and alienation of aerobic bacteria are used to degrade organic matter. At the same time, the aerobic pool increases the gas-liquid interface through mechanical stirring, which strengthens the integration of oxygen. Therefore, the microbial flora is the main body of gelatin processing wastewater purification, and the treatment effect and water quality changes of the biological system are closely related to the structure and function of the microbial community.

[0071] The V-type filter 13 is installed above the hydrolysis tank 121, the anoxic tank 122, the aerobic tank 123 and the secondary sedimentation tank 124. The primary filtered water of the V-type filter 13 enters the reflow tank 14, and the backwash water of the V-type filter 13 enters the drainage tank 15; the supernatant of the reflow tank 14 and the drainage tank 15 flows back to the first grid 1 or the second grid 4.

[0072] S4: The sludge from the pre-sedimentation tank 3, the folded plate flocculation tank 8, the horizontal flow sedimentation tank 9, the inclined tube sedimentation tank 10, the AO biochemical tank 12, the drainage tank 15, etc. is discharged into the sludge discharge tank 16, and the supernatant of the sludge discharge tank 16 is returned to the first grid 1 or the second grid 4. The sludge in the sludge discharge tank 16 enters the sludge balance tank 17 after being concentrated, and is transported out after being dehydrated. The unused sludge such as sedimentation or activated sludge is transported out after being concentrated, dehydrated, and dried for safe landfill; the supernatant is recycled to reduce water consumption.

[0073] In summary, the gelatin production wastewater in the present invention is pre-aerated after pretreatment. During the pre-aeration process, air and ozone are used for aeration treatment. On the basis of reducing the pollutants in the AO biochemical pool 12, a part of the organic matter in the gelatin wastewater cannot be oxidized. After being catalyzed by H2O2 and oxidized by ozone, it is converted into organic matter that can be chemically oxidized, and then adsorbed and absorbed by the activated sludge in the AO biochemical pool 12, thereby improving the COD removal effect, and it is significantly higher than the biochemical effluent of other processes;

[0074] The supernatant after pre-aeration treatment enters the static mixer 7, and then passes through the folded plate flocculation tank 8, the horizontal flow sedimentation tank 9 and the inclined tube sedimentation tank 10 in sequence. The tubular static mixer 7 shortens the mixing time. At the same time, a heating steam pipe 11 is provided on the tubular static mixer 7, which shortens the mechanical mixing time. The DN15 steam pipe heating means that each pipe and the steam heating pipe are close together for insulation, which can reduce the risk of the reagent being easily blocked by the pipe due to temperature drop and reduced solubility;

[0075] The folded plate flocculation tank 8, the horizontal flow sedimentation tank 9 and the inclined tube sedimentation tank 10 are designed in sequence, so that the wastewater can be flocculated and precipitated multiple times to remove impurities before entering the AO biochemical tank 12, thereby reducing the action time of the AO biochemical tank 12, thereby reducing the amount of activated sludge, etc., and saving wastewater treatment costs.

[0076] Second embodiment

[0077] Please refer to Figure 1 and 2 This embodiment provides an embodiment of the present invention also provides a gelatin production wastewater deep treatment equipment, which includes:

[0078] A first grid 1, a grey water collection tank 2 and a pre-sedimentation tank 3 connected in sequence;

[0079] The second grid 4, the comprehensive wastewater collection tank 5, and the pre-aeration regulating tank 6 are connected in sequence; the supernatant of the pre-sedimentation tank 3 is connected to the comprehensive wastewater collection tank 5 through a pipeline;

[0080] The supernatant of the pre-aeration regulating tank 6 is connected to the static mixer 7, the folded plate flocculation tank 8, the advection sedimentation tank 9 and the inclined tube sedimentation tank 10 in sequence through pipelines;

[0081] The supernatant of the inclined tube sedimentation tank 10 is connected to the AO biochemical tank 12 and the V-type filter tank 13 in sequence through pipelines; the primary filtered water of the V-type filter tank 13 is connected to the return tank 14 through pipelines, and the backwash water of the V-type filter tank 13 is connected to the drainage tank 15 through pipelines; the supernatant of the return tank 14 and the drainage tank 15 is connected to the water inlet of the first grid 1 or the second grid 4 through pipelines;

[0082] The pre-sedimentation tank 3, the folded plate flocculation tank 8, the horizontal flow sedimentation tank 9, the inclined tube sedimentation tank 10, the AO biochemical tank 12, and the drainage tank 15 scrape the bottom sludge through the sludge scraping equipment and connect to the sludge discharge tank 16 through the sludge discharge pump; the supernatant of the sludge discharge tank 16 is connected to the water inlet of the first grid 1 or the second grid 4 through a pipeline; the sludge in the sludge discharge tank 16 enters the sludge balance tank after being concentrated, and is transported out after being dehydrated.

[0083] This specification describes examples of embodiments of the present invention, and it is not intended that these embodiments illustrate and describe all possible forms of the present invention. It should be understood that the embodiments in the specification can be implemented in a variety of alternative forms. The drawings need not be drawn to scale; some features can be enlarged or reduced to show the details of specific components. The specific structural and functional details disclosed should not be interpreted as limiting, but are merely representative bases for teaching those skilled in the art to implement the present invention in various forms. It should be understood by those skilled in the art that the multiple features illustrated and described with reference to any of the drawings can be combined with the features illustrated in one or more other drawings to form embodiments that are not explicitly illustrated or described. The described combined features provide representative embodiments for typical applications. However, various combinations and variations of features consistent with the teachings of the present invention can be used for specific applications or implementations as needed.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for deep treatment of gelatin production wastewater, characterized in that: The steps include: The first-class workshop wastewater is sequentially introduced into the gray water collection tank after impurities are removed through the first grille. After air is introduced into the gray water collection tank, the mixed liquid is pumped into the pre-sedimentation tank through the first extraction pump; After the second-class workshop wastewater is sequentially passed through the second grid to remove impurities, it is introduced into the comprehensive wastewater collection tank. After the comprehensive wastewater collection tank is introduced with air, the mixed liquid is extracted into the pre-aeration regulating tank through the second extraction pump; the supernatant in the pre-sedimentation tank flows into the comprehensive wastewater collection tank; The supernatant in the pre-aeration regulating tank is extracted and enters the static mixer, in which a coagulant is arranged, and the mixed sewage passes through the folded plate flocculation tank, the horizontal flow sedimentation tank and the inclined tube sedimentation tank in sequence; The supernatant in the inclined tube sedimentation tank is sequentially introduced into the AO biochemical tank and the V-type filter tank, the primary filtered water of the V-type filter tank enters the return tank, and the backwash water of the V-type filter tank enters the drainage tank; the supernatant of the return tank and the drainage tank flows back to the first grid or the second grid; The sludge in the pre-sedimentation tank, the folded plate flocculation tank, the horizontal flow sedimentation tank, the inclined tube sedimentation tank, the AO biochemical tank and the drainage tank is discharged into the sludge discharge tank, the supernatant of the sludge discharge tank is returned to the first grid or the second grid, the sludge in the sludge discharge tank is concentrated and then enters the sludge balance tank, and is transported out after dehydration.

2. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: The AO biochemical tank includes a hydrolysis tank, an anoxic tank, an aerobic tank and a secondary sedimentation tank connected in sequence. The mixed liquid of the aerobic tank is returned to the anoxic tank; the sludge of the secondary sedimentation tank is returned to the hydrolysis tank; the supernatant of the secondary sedimentation tank is introduced into the static mixer through the third extraction pump, and the residual sludge of the secondary sedimentation tank enters the sludge discharge tank.

3. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: The folded plate flocculation tank is provided with three flocculation zones, each of which is provided with a folded plate combination consisting of 90° relative folded plates and 90° parallel folded plates. The residence time of the first flocculation zone is 4 min, the peak velocity is 0.3 m / s, the valley velocity is 0.07 m / s, and the G value is 94.5S -1 The residence time of the second flocculation zone is 5 min, the peak velocity is 0.2 m / s, and the G value is 58.4 S -1 The residence time in the third flocculation zone is 7 min, the peak velocity is 0.1 m / s, and the G value is 22.1 S -1 .

4. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: The first type of workshop wastewater is acid soaking workshop wastewater, phosphate calcium workshop wastewater, and liming workshop wastewater.

5. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: Polyaluminium chloride as a coagulant and polyacrylamide as a flocculant are added into the static mixer.

6. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: The pre-sedimentation tank and the horizontal flow sedimentation tank are provided with a traveling sludge suction machine, and a sludge concentration meter is provided on the branch pipe of the traveling sludge suction machine. When the sludge concentration reaches the set condition, the pneumatic valve is opened to discharge the sludge, and the sludge discharge vehicle continues to move forward. When it is 2m away from the flocculation tank, the pneumatic forced sludge discharge is turned on, and when the scraper is retracted, the pneumatic valve is closed.

7. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: The pre-aeration regulating tank is injected with ozone and air through a micro-nano bubble generating device, and the content ratio of ozone to air is 7-7.5:2.5-3.

8. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: The medicine inlet pipes of the static mixer and the folded plate flocculation tank are provided with heating steam pipes.

9. The method for advanced treatment of gelatin production wastewater according to claim 1, characterized in that: A bidirectional separation cyclone reaction sedimentation device is arranged in the pre-aeration regulating tank.

10. A gelatin production wastewater deep treatment equipment, characterized in that: include: A first grid, a grey water collection tank and a pre-sedimentation tank connected in sequence; The second grid, the comprehensive wastewater collection tank, and the pre-aeration regulating tank are connected in sequence; The supernatant of the pre-sedimentation tank is connected to the comprehensive wastewater collection tank through a pipeline; The supernatant of the pre-aeration regulating tank is connected to the static mixer, the folded plate flocculation tank, the advection sedimentation tank and the inclined tube sedimentation tank in sequence through pipelines; The supernatant of the inclined tube sedimentation tank is connected to the AO biochemical tank and the V-type filter tank in sequence through a pipeline; the primary filtered water of the V-type filter tank is connected to the return tank through a pipeline, and the backwash water of the V-type filter tank is connected to the drainage tank through a pipeline; the supernatant of the return tank and the drainage tank is connected to the water inlet of the first grid or the second grid through a pipeline; The pre-sedimentation tank, the folded plate flocculation tank, the horizontal flow sedimentation tank, the inclined tube sedimentation tank, the AO biochemical tank, and the drainage tank scrape the bottom sludge through the sludge scraping equipment and are connected to the sludge discharge tank through the sludge discharge pump; the supernatant of the sludge discharge tank is connected to the water inlet of the first grid or the second grid through a pipeline; the sludge in the sludge discharge tank enters the sludge balance tank after being concentrated, and is transported out after being dehydrated.

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