Low-energy consumption circulating liquor wastewater treatment device and use method thereof

Abstract

This application discloses a low-energy-consumption circulating wastewater treatment device for liquor wastewater, comprising multi-stage reaction tanks connected in series. Each stage of the reaction tank is equipped with a stirring device, a heating device, an exhaust valve, and a drain valve. It also includes an oxygen-releasing material, which is periodically removed from the previous stage reaction tank and placed into the next stage reaction tank according to the arrangement of the multi-stage reaction tanks. By applying this oxygen-releasing material to liquor wastewater treatment, and adjusting the order in which it is added, oxygen is supplied using a purely physical method without the need for other electrical equipment, thus achieving energy savings.

Description

Technical Field

[0001] This invention relates to the field of liquor wastewater treatment technology, specifically to a low-energy-consumption circulating liquor wastewater treatment device and its usage method. Background Technology

[0002] my country has a huge market demand for baijiu (Chinese liquor), and its brewing process generates a large amount of baijiu wastewater. Statistics show that producing 1 ton of baijiu produces 20-40 tons of wastewater, and in recent years, my country's annual baijiu wastewater discharge has exceeded 100 million tons. Baijiu wastewater not only contains high concentrations of dissolved organic matter, such as polysaccharides, glycerol, methanol, ethanol, fatty acids, amino acids, aldehydes, and esters, but also high levels of suspended solids (SS), high COD, high BOD, high color, low pH, low dissolved oxygen, high total nitrogen, and high organic nitrogen. Baijiu wastewater is characterized by its high biodegradability and difficulty in treatment. The discharge of inadequately treated baijiu wastewater leads to the proliferation of algae, a significant depletion of dissolved oxygen (DO) in water bodies, and the inability of aquatic plants and animals to survive normally, causing serious damage to aquatic ecosystems. If baijiu wastewater seeps into the soil, it will inhibit plant growth and reproduction and cause some harm to terrestrial animals. Furthermore, it may alter the unique microbial communities in local soil and water systems, impacting the economic benefits of the local baijiu industry.

[0003] Organic nitrogen in baijiu wastewater is decomposed by microorganisms to produce ammonia nitrogen. If this ammonia nitrogen exceeds the treatment capacity of the process, it may lead to excessive levels of ammonia nitrogen in the effluent. The treatment of ammonia nitrogen in baijiu wastewater mainly relies on the decomposition of nitrifying organisms. Most nitrogen-converting microorganisms are sensitive to changes in dissolved oxygen (DO), therefore, DO is a crucial factor affecting the denitrification effect of baijiu wastewater.

[0004] The problem of low dissolved oxygen (DO) and high ammonia nitrogen (AM) in baijiu (Chinese liquor) wastewater has received widespread attention. A common wastewater treatment approach combines physicochemical methods with anaerobic and aerobic biological methods, achieving good COD removal efficiency. Common physicochemical methods include flotation, coagulation, and hydrolysis acidification; common biological processes include IC (integrated electrolyte solution) + secondary A / O tank, UASB + SBR (semi-aerobic bioreactor), AFB (aerobically fed biological reactor), UASB + biological contact oxidation, EGSB + CASS (chemically activated carbon monoxide solution), etc. Various traditional and new processes have improved the situation of low DO and high AM in baijiu wastewater to some extent. However, because the aerobic stage relies on aeration, the DO concentration in the aerobic phase of these traditional and new baijiu wastewater treatment processes is usually controlled below 2.0 mg / L. Within this DO concentration range, microorganisms have a certain removal effect on ammonia nitrogen, but there is still room for optimization.

[0005] Studies have shown that increasing dissolved oxygen (DO) concentration not only promotes the removal rate of organic matter in the reactor, but also increases the removal rates of both COD and ammonia nitrogen. DO at concentrations of 4.31-5.16 mg / L promotes the synthesis of more branched-chain fatty acids (BFA) by microorganisms to maintain high cell membrane fluidity. Furthermore, research on water treatment microorganisms at different DO concentrations indicates that the concentration of Bacteroidetes increases with increasing DO, and the content of Flavobacterium is more than 10 times higher at a DO concentration of 4.0 mg / L than at 3.0 mg / L. Flavobacterium is a bacterium with strong heterotrophic nitrification capabilities, and some strains also possess aerobic denitrification abilities. Therefore, appropriately increasing the DO concentration is more beneficial for improving the nitrification effect of ammonia nitrogen.

[0006] Based on the actual conditions of wastewater treatment plants both domestically and internationally, when design discharge standards are not met, the electricity consumption for treating 1 ton of wastewater ranges from 0.5 to 1.5 kWh. Among these, the secondary biological treatment aeration system consumes the most energy, accounting for approximately 50% to 65% of the total electricity consumption. During the operation of wastewater treatment plants, a significant amount of electricity, resources, and funds are wasted due to the long-term aeration requirements.

[0007] The inventors previously applied for an oxygen-slow-release material for improving the bottom environment of aquatic bodies, as well as its preparation method and apparatus (application number: 201810311986.2). This material includes a porous medium and a coating layer, and also includes oxygen contained within the pores of the porous medium. The coating layer covers the surface of the porous medium, sealing the oxygen within its pores. Using the pores of the porous medium as the oxygen carrier and pure oxygen as the oxygen source, the oxygen-slow-release material does not produce strong oxidizing or alkaline substances when reintroduced into water, which is beneficial for the growth and reproduction of microorganisms and plants. Simultaneously, the coating layer allows for the slow release of oxygen, maintaining a certain level of dissolved oxygen at the bottom of the water body for several days, continuously providing an aerobic environment for plants and microorganisms.

[0008] Therefore, the applicant applied the oxygen slow-release material to the treatment of liquor wastewater. By adjusting the order of adding the oxygen slow-release material, oxygen was filled using a purely physical method without the need for other electrical equipment, thus achieving the goal of saving energy consumption. To a certain extent, this increased the DO concentration in the biological treatment tank of liquor wastewater, thereby improving the removal rate of ammonia nitrogen. Summary of the Invention

[0009] The present invention aims to provide a low-energy-consumption circulating baijiu wastewater treatment device and its usage method. By adjusting the addition sequence of oxygen slow-release materials, oxygen is filled by a purely physical method without other electrical equipment, thereby achieving the purpose of saving energy consumption. To a certain extent, it increases the DO concentration in the biological treatment tank of baijiu wastewater, thereby improving the removal rate of ammonia nitrogen.

[0010] To achieve the above objectives, the present invention provides the following technical solution:

[0011] A low-energy-consumption circulating baijiu wastewater treatment device includes multi-stage reaction tanks connected in series. Each stage of the reaction tank is equipped with a stirring device, a heating device, an exhaust valve, and a drain valve. It also includes an oxygen-releasing material, which is taken out from the previous stage reaction tank and placed into the next stage reaction tank according to a certain cycle in the arrangement of the multi-stage reaction tanks.

[0012] Ideally, the stirring device is specifically a stirring foot.

[0013] Ideally, the heating device is specifically a heating plate.

[0014] Ideally, a pressure pump is installed between adjacent reaction vessels.

[0015] Ideally, the reactor comprises four stages connected in series: reactor a, reactor b, reactor c, and reactor d.

[0016] A method for using a low-energy-consumption circulating baijiu wastewater treatment device, characterized by the following steps:

[0017] S1. Add oxygen slow-release material at a ratio of 1 cubic meter of material to 10 cubic meters of water, and add the oxygen slow-release material to the reaction tank d on day 0.

[0018] S2. On the 10th day, remove the oxygen-releasing material from reaction vessel d and add it to reaction vessel c;

[0019] S3. On the 20th day, remove the oxygen-releasing material from reaction vessel c and add it to reaction vessel b;

[0020] S4. On the 30th day, remove the oxygen-releasing material from reaction vessel b and add it to reaction vessel a;

[0021] S5. On the 40th day, remove the oxygen slow-release material from reaction vessel a, and then prepare new oxygen slow-release material to repeat the process from S1 to S5. This 40-day cycle is one cycle.

[0022] Ideally, the liquor wastewater, after being filtered through a screen and sedimentation tank, flows through reaction tanks d, c, b, and a.

[0023] Ideally, the liquor wastewater, after being filtered through the screen and sedimentation tank, flows through reaction tanks d, c, b, and a.

[0024] Ideally, the residence time of the liquor wastewater in reaction tanks d, c, and b is 2–3 hours, and the residence time in reaction tank a is 6–8 hours.

[0025] Ideally, the lower half of the reaction tank c is not filled with packing material to form a suspended sludge layer, while the upper half is still filled with packing material. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of a low-energy-consumption, circulating baijiu wastewater treatment device for the invention. Detailed Implementation

[0027] The following detailed description illustrates the specific implementation method:

[0028] In the following statements, directional terms such as "left," "right," "up," and "down" are based on the directions shown in the diagram. In practice, if the corresponding structures are changed in the same direction based on the direction while maintaining their relative positions, it will not affect the implementation of the plan.

[0029] Example: A low-energy-consumption circulating baijiu wastewater treatment device includes four reaction tanks, namely reaction tank a, reaction tank b, reaction tank c and reaction tank d.

[0030] An oxygen-releasing material (particle size 3-5mm) was prepared according to my previously filed patent (see patent "An Oxygen-Release Material for Improving the Bottom Environment of Water Bodies and Its Preparation Method and Device" (201810311986.2)). Based on the oxygen release cycle of this material, taking a 40-day oxygen release cycle as an example, the oxygen-releasing material was added at a ratio of 1 cubic meter of material per 10 cubic meters of wastewater treated.

[0031] First, on day 0, the oxygen-releasing material was added to reaction tank d (for the next 10 days, tank d was an aerobic tank, and the dissolved oxygen concentration do increased from 0 mg / L to 5.2 mg / L, and then gradually decreased to 2.0 mg / L);

[0032] Then, on the 10th day, the oxygen-releasing material was removed from reaction tank d and added to reaction tank c (at this time, tank c is an aerobic tank, and the dissolved oxygen concentration rises from 0 mg / L to 5.2 mg / L, and then gradually decreases to 2.0 mg / L). Tank d is an anoxic tank, and the dissolved oxygen concentration gradually decreases from 2 mg / L to 0.5 mg / L.

[0033] On the 20th day, the oxygen-releasing material was removed from reaction tank c and added to reaction tank b. At this time, tank b was an aerobic tank, and the dissolved oxygen concentration increased from 0 mg / L to 5.2 mg / L, and then gradually decreased to 2.0 mg / L. Tank c was an anoxic tank, and the dissolved oxygen concentration gradually decreased from 2 mg / L to 0.5 mg / L. Tank d was an anaerobic tank, and the dissolved oxygen concentration gradually decreased from 0.5 mg / L to 0 mg / L.

[0034] On day 30, the oxygen-releasing material was removed from reaction vessel b and added to reaction vessel a. At this time, vessel a was an aerobic vessel, with the dissolved oxygen concentration increasing from 0 mg / L to 5.2 mg / L and then gradually decreasing to 2.0 mg / L; vessel b was an anoxic vessel, with the dissolved oxygen concentration decreasing from 2 mg / L to 0.5 mg / L; and vessel c was an anaerobic vessel, with the dissolved oxygen concentration decreasing from 0.5 mg / L to 0 mg / L.

[0035] Tank d is an anaerobic digestion tank without any material, with a dissolved oxygen concentration of 0 mg / L. On day 40, the process of day 0 is repeated. The material in tank d is taken out, cleaned and dried, and new oxygen slow-release material is placed in it. This 40-day cycle is one cycle.

[0036] Taking the operation from day 30 to 40 as an example, the operating status of the device is described. At the start of operation, the effluent from the physical structures such as the screen chamber and sedimentation tank (to prevent clogging) first enters reaction tank d, where it remains for 2 hours for anaerobic digestion (at this time, tank d is an anaerobic digestion tank without materials, with a dissolved oxygen concentration of 0 mg / L). Heating is performed by heating plate 9 (only heating plate 9d is used; the other three heating plates 9a, 9b, and 9c are not heated) at a mesophilic digestion temperature (33–35℃). Simultaneously, stirring foot 10 (only stirring foot 10d is used; the other three stirring feet 10a, 10b, and 10c are not used) is activated at a rate of 0.15–0.30 m / s to stir the high-concentration liquor wastewater. Four exhaust valves 8 are opened; 8d and 8c release biogas from reaction tank d, while 8a and 8b connect the reaction tank to the atmosphere to maintain stable pressure.

[0037] Next, the liquor wastewater, after remaining in reaction tank d for 24 hours, enters reaction tank c through the top outlet pipe, valve 3d, booster pump 11d, and valve 4d, where it remains for 2 hours, completing the anaerobic phosphorus release and ammoniation process. At this point, tank c is an anaerobic tank with a dissolved oxygen concentration of 0.5–0 mg / L. The operating principle of tank c is the same as that of an anaerobic biological filter, but the lower half is not filled with packing material, creating a suspended sludge layer, while the upper half still uses a packed bed, forming a composite anaerobic biological filter. This effectively avoids clogging and improves treatment efficiency. Anaerobic treatment occurs through the adsorption of porous materials and the multiple effects of the anaerobic biofilm.

[0038] Next, the effluent from reaction tank c enters reaction tank b through the top outlet pipe, valve 3c, booster pump 11c, and valve 4c, where it remains for 2 hours, completing the anoxic denitrification process. At this time, tank b is an anoxic tank with a dissolved oxygen concentration of 0.5–2 mg / L. In reaction tank d, the oxygen-carrying material releases DO over a certain period to create an anoxic environment, where anoxic denitrification and other treatments occur under the adsorption of porous materials and the combined effects of the anoxic biofilm.

[0039] Finally, the wastewater from reactor b exits through the top outlet pipe of reactor b, passes through valve 3b, booster pump 11b, and valve 4b, and enters reactor a to complete the processes of phosphorus adsorption, nitrification, and BOD removal. The residence time in reactor a is 6 hours. The addition of oxygen-carrying material to reactor a coincides with the water treatment time, resulting in a dissolved oxygen concentration of 5.2–2.0 mg / L, creating an aerobic environment. Aerobic treatment occurs through the adsorption of porous materials and the combined effects of the aerobic biofilm.

[0040] The time for adding oxygen-carrying material to each reaction tank and the time for changing the reaction tank are controlled online by the values ​​displayed on the DO meter 8 at the top of the reaction tank, so that the DO of the four baijiu wastewater reaction tanks are controlled within the required dissolved oxygen range of 0-0.5 mg / L, 0-0.5 mg / L, 1-2 mg / L and 4.3-5.2 mg / L respectively.

[0041] An effluent detection device is installed at valve 3. If the effluent discharge standard is met in one run, the tailwater can be discharged from the aerobic reaction tank through valves 3a and 6. If the effluent does not meet the discharge standard, the effluent from reaction tank a can be circulated into reaction tank d through valve 3, pressurizing pump 11 and valve 5a, and the dcba treatment process can be continued until the effluent meets the standard and is discharged through valve 6.

[0042] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

Claims

1. A method for using a low-energy consumption circulating liquor wastewater treatment device, comprising reaction tanks connected in series and multiple stages, each reaction tank being provided with a stirring device, a heating device, an exhaust valve, and a drain valve, characterized in that: It also includes oxygen-releasing materials, which are taken out from the previous stage reaction tank and placed in the next stage reaction tank according to a certain period of time in the arrangement of the multi-stage reaction tanks; including four reaction tanks connected in series, namely reaction tank a, reaction tank b, reaction tank c and reaction tank d; The process includes the following steps: S1, add oxygen-releasing material at a ratio of 1 cubic meter of material to 10 cubic meters of water, and add the oxygen-releasing material to reaction tank d on day 0; S2, remove the oxygen-releasing material from reaction tank d on day 10 and add it to reaction tank c; S3, remove the oxygen-releasing material from reaction tank c on day 20 and add it to reaction tank b; S4, remove the oxygen-releasing material from reaction tank b on day 30 and add it to reaction tank a; S5, remove the oxygen-releasing material from reaction tank a on day 40, and prepare new oxygen-releasing material to repeat the process from S1 to S5. This 40-day cycle is one period. After being filtered through a screen and sedimentation tank, the liquor wastewater flows sequentially through reaction tanks d, c, b, and a. The residence time of the liquor wastewater in reaction tanks d, c, and b is 2–3 hours, and the residence time in reaction tank a is 6–8 hours. The oxygen release cycle of the oxygen slow-release material is 40 days.

2. The method of using the low-energy-consumption circulating liquor wastewater treatment device according to claim 1, characterized in that: The stirring device is specifically a stirring foot.

3. The method of using the low-energy-consumption circulating liquor wastewater treatment device according to claim 2, characterized in that: The heating device is specifically a heating plate.

4. The method of using the low-energy consumption circulating type Baijiu wastewater treatment device according to claim 3, characterized in that: A pressure pump is installed between adjacent reaction vessels.

5. The method of using the low-energy-consumption circulating liquor wastewater treatment device according to claim 4, characterized in that: The lower half of the reaction tank c is not filled with packing material to form a suspended sludge layer, while the upper half is still filled with packing material.

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