A sludge in-situ reduction device and process for biochemical sewage treatment

Abstract

The present invention provides an in-situ sludge reduction device and process for biochemical sewage treatment, comprising a biochemical tank, a sedimentation tank, and a first microbial inactivation reaction device; a delivery pipe and a return pipe are respectively provided between the biochemical tank and the sedimentation tank. The present invention utilizes an electrochemical oxidation-reduction method to inactivate and modify the sludge in the biochemical system. Because the microbial inactivation reaction device selectively kills microorganisms in the sludge, nitrifying and denitrifying bacteria, facultative oxic hydrolytic bacteria, and other facultative oxic bacteria with slower reproduction rates are effectively enriched, thereby significantly improving the biochemical system's ability to reduce total nitrogen and degrade low-biodegradable pollutants, thereby enhancing the biochemical system's sewage treatment effect and capacity. Furthermore, chemical, physical, or biological methods are used to digest the microbial debris that has been broken and inactivated, reducing sludge output and achieving in-situ sludge reduction.

Description

Technical Field

[0001] The invention belongs to the technical field of biochemical sewage treatment, and particularly relates to a sludge in-situ reduction device and process for biochemical sewage treatment. Background Art

[0002] Sludge, a byproduct of biochemical wastewater treatment, is an extremely complex, heterogeneous mass composed of organic debris, bacterial cells, inorganic particles, and colloids. According to data from China's Ministry of Environmental Protection, by the end of 2021, the daily treatment capacity of urban sewage treatment facilities nationwide had reached 360 million tons. With the continuous improvement of urbanization and people's living standards, the amount of sludge generated nationwide is expected to increase further in the future. The main characteristics of sludge are high moisture content and high organic matter content, which makes it easily decompose and odorize. It also has fine particles, a low specific gravity, and a colloidal liquid state. Sludge contains a large amount of organic matter, such as benzene, chlorophenols, polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), and polychlorinated dibenzo-p-dioxins (PCDDs); pathogenic microorganisms such as parasite eggs; and heavy metals such as cadmium, chromium, copper, and zinc. Improper handling can easily cause secondary pollution to the environment. To reduce environmental pollution and lower disposal costs, excess sludge from municipal sewage treatment plants needs to be reduced, stabilized, and rendered harmless.

[0003] At present, the main methods of disposing residual sludge from urban sewage treatment plants in my country are compressed landfill, composting and incineration.

[0004] 1. Compression landfill: The sludge is compressed and then buried in a dedicated landfill. The advantage is that the sludge can be reduced to a minimum, but the disadvantage is that it requires a large amount of land and produces harmful substances such as leachate, which may pollute groundwater.

[0005] 2. Composting: Sludge and organic waste are fermented and composted together to produce high-quality organic fertilizer. The advantage of this method is that it can reduce the amount of sludge while producing organic fertilizer. However, the disadvantage is that composting takes a long time and produces odor, which is a nuisance to residents.

[0006] 3. Incineration: Sludge is incinerated at high temperatures to eliminate all organic matter, producing ash and flue gas. The advantage is that the sludge can be minimized, and the flue gas can be discharged after treatment. The disadvantage is that incineration requires a lot of energy, is costly, and produces harmful gases such as carbon dioxide.

[0007] When selecting a specific treatment technology, factors such as the nature of urban surplus sludge, the scale of the treatment facilities and the operating costs need to be considered.

[0008] Before sludge disposal, some dewatering technologies are usually used to reduce the volume and weight of sludge to reduce the load of subsequent sludge disposal and reduce disposal costs. Currently, there are several sludge reduction technologies:

[0009] 1. Biological method: By changing the activity of sludge and environmental conditions, the growth and metabolism of microorganisms are promoted, organic matter is degraded, and thus the generation of sludge is reduced.

[0010] 2. Physical method: Use physical methods to treat sludge, such as filter pressing, centrifugation, compression, ozone, ultrasound, etc., to remove moisture and organic matter in the sludge to achieve the purpose of reducing the amount.

[0011] 3. Chemical method: Use chemical methods to oxidize and decompose organic matter in sludge, thereby reducing the amount of sludge.

[0012] 4. Thermal method: Dry the sludge to evaporate its water, thereby reducing the weight and volume of the sludge.

[0013] 5. Biocharization method: Use biocharization technology to treat sludge and convert organic matter into biochar, thereby reducing the volume and weight of sludge.

[0014] Appropriate sludge reduction technologies need to be selected based on specific circumstances. However, these technologies generally suffer from high energy consumption and reagent costs, and also have certain impacts on subsequent sludge disposal. Therefore, environmental and safety issues must be taken into consideration during use. Summary of the Invention

[0015] Technical problem to be solved: Currently, the most common method is to discharge wastewater into a sedimentation tank after treatment in a biochemical tank. A portion of the sludge is returned to the biochemical tank for continued use, while the remaining portion is transported out and dewatered at the back end to reduce the volume and weight of the sludge. The present invention provides an in-situ sludge reduction device and process for biochemical wastewater treatment. By installing a microbial inactivation reaction device in the process flow, the sludge in the biochemical system is inactivated and modified using an electrochemical redox method to improve the biodegradability of the sludge. The microbial debris that has been broken and inactivated is digested through chemical, physical, or biological methods to reduce sludge output and achieve in-situ sludge reduction.

[0016] Technical solution: A sludge in-situ reduction device for biochemical sewage treatment, comprising a biochemical tank, a sedimentation tank, and a first microbial inactivation reaction device; a delivery pipe and a return pipe are respectively provided between the biochemical tank and the sedimentation tank, the delivery pipe is used to deliver the treated sewage in the biochemical tank to the sedimentation tank; the return pipe is used to return the sludge in the sedimentation tank to the biochemical tank; a reflux pump and a first microbial inactivation reaction device are installed on the return pipe.

[0017] Furthermore, the first microorganism inactivation reaction device includes a PLC control system, a microorganism inactivation reactor, a backwash device, a sewage tank, a main line pipeline, a backwash pipeline and a bypass pipeline; the main line pipeline and the backwash pipeline are installed at both ends of the microorganism inactivation reactor, and a first valve and a second valve are installed at both ends of the main line pipeline; a third valve and a fourth valve are installed on the backwash pipeline respectively; the sewage tank is connected to the microorganism inactivation reactor through the backwash pipeline and the third valve; the backwash device is connected to the microorganism inactivation reactor through the backwash pipeline and the fourth valve, and is controlled by the PLC control system for backwashing and clearing blockages; the bypass pipeline is connected to the main line pipeline in parallel with the microorganism inactivation reactor, and a fifth valve is installed on the bypass pipeline; the PLC control system is connected to the microorganism inactivation reactor, the backwash device, the first valve, the second valve, the third valve, the fourth valve and the fifth valve, the pressure gauge and the sludge concentration meter placed in the biochemical tank by pipelines, and controls their use and start and stop; the first microorganism inactivation reaction device is connected to the biochemical tank and the sedimentation tank respectively through both ends of the main line pipeline.

[0018] Furthermore, the microbial inactivation reactor is a fluid static device composed of a group of alloy sleeves with microbial inactivation function based on a multiple redox potential system. The alloy sleeves have internal rifling, which can change the flow process and turbulent state of the fluid in the tube bundle, prolong and strengthen the contact time and intensity between the microorganisms and the alloy material, and improve the inactivation efficiency of the microorganisms. The formula of the alloy sleeve material is as follows, in weight percentage: zinc: 28%-35%, tin: 4%-7%, nickel: 19%-26%, lanthanum 0.2-0.5%, samarium 0.3-1%, lutetium 1-2%, and the balance is copper.

[0019] Furthermore, the backwash device closes the first valve and the second valve through the PLC control system according to the pressure gauge signal, and opens the third valve, the fourth valve and the fifth valve and the sewage pump to remove impurities that block the microorganism inactivation reactor.

[0020] A sludge in-situ reduction process for biochemical sewage treatment comprises the following steps:

[0021] Step 1: After the biochemical wastewater enters the biochemical pool for purification, it flows through the delivery pipe to the sedimentation tank for sedimentation. The purified water is discharged, and the sludge in the sedimentation tank is extracted by the reflux pump and pumped through the reflux pipe to the first microbial inactivation reaction device to break down the microorganisms in the sludge and inactivate them;

[0022] Step 2: The treated sludge is pumped out by the reflux pump and continues to flow back to the biochemical pool. The broken and inactivated microbial debris is digested by chemical, physical or biological methods to reduce the output of sludge and achieve in-situ sludge reduction.

[0023] Furthermore, the biological method in step 2 includes directly adding high-efficiency composite engineered bacteria and adding high-efficiency composite engineered bacteria after acclimation and expansion.

[0024] Furthermore, a temporary bacteria cultivation device is provided for acclimating and expanding the high-efficiency composite engineering bacteria; the temporary bacteria cultivation device includes a second microorganism inactivation reaction device, a temporary bacteria cultivation tank and a switchable self-priming sewage pump device; the second microorganism inactivation reaction device has the same structure as the first microorganism inactivation reaction device; the temporary bacteria cultivation tank has a built-in plug flow agitator, which is connected to the sedimentation tank and the biochemical tank through a switchable self-priming sewage pump device, and is connected to the second microorganism inactivation reaction device through a circulation pump and a pipeline to form an internal circulation system, which continuously performs property modification treatment on the residual sludge, thereby acclimating and expanding the high-efficiency composite engineering bacteria.

[0025] Furthermore, a sixth valve is installed between the switchable self-priming sewage pump device and the biochemical tank, a seventh valve is installed between the switchable self-priming sewage pump device and the sedimentation tank, and an eighth valve and a ninth valve are installed at both ends of the temporary bacteria culture tank respectively; the switchable self-priming sewage pump device can pump the residual sludge in the sedimentation tank into the temporary bacteria culture tank through the switching of the sixth valve, the seventh valve, the eighth valve and the ninth valve, and can also introduce the high-efficiency composite engineering bacteria domesticated and expanded in the temporary bacteria culture tank into the biochemical tank.

[0026] Furthermore, the domestication and expansion of the high-efficiency composite engineered bacteria includes the following steps:

[0027] Step 1: Sludge is pumped from the sedimentation tank to a temporary culture tank. The sludge in the temporary culture tank is treated by a second microbial inactivation reaction device and then returned to the temporary culture tank. The sludge in the temporary culture tank is continuously modified by the second microbial inactivation reaction device to obtain modified sludge. High-efficiency composite engineered bacteria are then added to the temporary culture tank. Under the action of the second microbial inactivation reaction device, the modified sludge is used as a culture medium to acclimate and expand the high-efficiency composite engineered bacteria.

[0028] Beneficial effects:

[0029] 1. The present invention uses a microbial inactivation reaction device to cause the sludge to be broken and inactivated during the confluence process. The treated sludge is extracted by a reflux pump and continues to flow back to the biochemical pool. The broken and inactivated microbial remains are then digested by chemical, physical or biological methods, thereby reducing sludge output and achieving in-situ sludge reduction.

[0030] 2. The present invention provides a microbial inactivation reaction device in the process flow and applies an electrochemical redox method to inactivate and modify the sludge in the biochemical system. Since the microbial inactivation reaction device (mainly composed of an alloy material) has the function of selectively killing microorganisms in the sludge, the so-called "selectivity" refers to the fact that since microorganisms exist in the form of bacterial flocs in the water body, microorganisms that are easy to grow and gather on the surface of the bacterial flocs are inactivated by cell wall rupture through the electrochemical redox reaction on the surface of the alloy material, thereby effectively enriching nitrifying and denitrifying bacteria, facultative anaerobic hydrolytic bacteria, and other facultative anaerobic bacteria with slower reproduction rates within the bacterial flocs, thereby significantly improving the biochemical system's ability to reduce total nitrogen and degrade low-biodegradable pollutants. While achieving sludge reduction, it also improves the sewage treatment effect and capacity of the biochemical system.

[0031] 3. The present invention arranges the microorganism inactivation reaction device on the reflux pipe, and the sludge reflux itself also requires the use of a reflux pump, so there is no additional increase in energy consumption.

[0032] 4. In conventional water treatment processes, it is necessary to regularly add carbon source nutrients such as glucose to replenish the microorganisms in the sludge. However, after the microbial inactivation reaction device in the present invention performs cell wall breaking and inactivation treatment on the microorganisms in the sludge, the microbial cells rupture, producing cell fluid, sugars, and nitrogen substances, which flow back into the biochemical pool and can serve as nutrients for the microorganisms in the sludge, reducing the addition of carbon source nutrients such as glucose and greatly saving costs.

[0033] 5. The present invention adopts a special alloy casing material. The alloy pipe material is composed of zinc, tin, nickel, lanthanum, samarium, lutetium and copper. Different elements have different redox potentials, and different potential differences are generated between the elements. Countless complex tiny primary batteries with different electrode potentials are formed in the water, which increases the oxidizability of the alloy material. The moment the alloy comes into contact with water, the redox potential of the water at the contact surface can undergo an impact change, destroying the cell wall of microorganisms, inhibiting the growth and reproduction of microorganisms, and facilitating the selective cell wall breaking and inactivation of microorganisms in water treatment.

[0034] 6. The alloy sleeve of the present invention has internal rifling, which can change the flow process and turbulence state of the fluid in the tube bundle, prolong and strengthen the contact time and intensity between microorganisms and the alloy material, thereby improving the inactivation efficiency of microorganisms.

[0035] 7. The present invention can also establish a temporary bacterial cultivation device, using the sludge in the sedimentation tank, after being modified by the microbial inactivation reactor, as a culture medium for the high-efficiency composite engineered bacteria. Under the action of the microbial inactivation reactor, the high-efficiency composite engineered bacteria are acclimated and expanded. After a period of acclimation and expansion, all the high-efficiency composite engineered bacteria in the cultivation tank are transferred from the cultivation tank to the biochemical tank, where the inactivated and modified sludge is digested by the "high-efficiency composite engineered bacteria" in the biochemical system. In subsequent engineering applications, if conditions permit, the excess sludge discharged from the sewage treatment plant that has implemented this in-situ sludge reduction technology can be directly used as the culture medium for the high-efficiency composite engineered bacteria that have been expanded and acclimated, thereby reducing the costs of temporary bacterial cultivation tank construction and the acclimation and expansion of the high-efficiency composite engineered bacteria. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a schematic structural diagram of the sludge in-situ reduction device for biochemical sewage treatment according to the present invention;

[0037] Figure 2 Schematic diagram of the structure of the first microorganism inactivation reaction device;

[0038] Figure 3 This is a schematic diagram of the structure of a temporary bacterial cultivation device;

[0039] Figure 4 This is the flow chart of traditional biochemical sewage treatment.

[0040] In the figure: 1. Biochemical pool; 2. Sedimentation tank; 3. First microorganism inactivation reaction device; 4. Delivery pipe; 5. Return pipe; 6. Return pump; 7. Temporary bacterial culture device; 302. Microorganism inactivation reactor; 303. Backwash device; 304. Sewage tank; 305. Main line; 306. Backwash line; 307. Bypass line; 308. First valve; 309. Second valve; 310. Third valve; 311. Fourth valve; 312. Fifth valve; 701. Second microorganism inactivation reaction device; 702. Temporary bacterial culture tank; 703. Switchable self-priming sewage pump device; 704. Sixth valve; 705. Seventh valve; 706. Eighth valve; 707. Ninth valve. DETAILED DESCRIPTION

[0041] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only 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 are within the scope of protection of the present invention.

[0042] like Figure 1As shown, a sludge in-situ reduction device for biochemical sewage treatment includes a biochemical tank 1, a sedimentation tank 2, and a first microorganism inactivation reaction device 3; a delivery pipe 4 and a return pipe 5 are respectively provided between the biochemical tank 1 and the sedimentation tank 2, the delivery pipe is used to deliver the treated sewage in the biochemical tank 1 to the sedimentation tank 2; the return pipe 5 is used to return the sludge in the sedimentation tank 2 to the biochemical tank 1; a reflux pump 6 and a first microorganism inactivation reaction device 3 are installed on the reflux pipe 5, and the first microorganism inactivation reaction device 3 is installed on the reflux pump 6, which can achieve wall-breaking and inactivation of the sludge without increasing energy consumption.

[0043] like Figure 2 As shown, the first microorganism inactivation reaction device 3 includes a PLC control system, a microorganism inactivation reactor 302 (a fluid static device composed of a group of alloy sleeves with a multi-redox potential system having a microorganism inactivation function, the alloy sleeves have internal rifling, which can change the flow process and turbulence state of the fluid in the tube bundle, prolong and strengthen the contact time and intensity between the microorganisms and the alloy material, and improve the inactivation efficiency of the microorganisms; in one embodiment, the alloy sleeve material formula is as follows, in weight percentage: zinc: 30%, tin: 7%, nickel: 23%, lanthanum 0.3%, samarium 0.8%, lutetium 1.6%, and the balance is copper), a backwash device 303, a sewage tank 304, a main line pipeline 305, a backwash pipeline 306 and a bypass pipeline 307; the main line pipeline 305 and the backwash pipeline 306 are installed at both ends of the microorganism inactivation reactor 302, and the first valve 308 and the second valve 309 are installed at both ends of the main line pipeline 305; 06 are respectively installed with a third valve 310 and a fourth valve 311; the sewage tank 304 is connected to the microorganism inactivation reactor 302 through the backwash pipeline 306 and the third valve 310; the backwash device 303 is connected to the microorganism inactivation reactor 302 through the backwash pipeline 306 and the fourth valve 311, and is controlled by the PLC control system for backwashing and clearing blockages; the bypass pipeline 307 is connected to the main line pipeline 305 in parallel with the microorganism inactivation reactor 302, and a fifth valve 312 is installed on the bypass pipeline 307; the PLC control system is connected to the microorganism inactivation reactor 302, the backwash device 30, the first valve 308, the second valve 309, the third valve 310, the fourth valve 311 and the fifth valve 312, the pressure gauge and the sludge concentration meter placed in the biochemical tank 1 by pipelines, and controls their use and start and stop; the first microorganism inactivation reactor 3 is respectively connected to the biochemical tank 1 and the sedimentation tank 2 through the two ends of the main line pipeline 305.

[0044] The backwash device 303 closes the first valve 308 and the second valve 309 through the PLC control system according to the pressure gauge signal, opens the third valve 310, the fourth valve 311 and the fifth valve 312 and the sewage pump to remove impurities that block the microorganism inactivation reactor (302).

[0045] The above-mentioned device is used to reduce the amount of sludge in situ from biochemical sewage treatment, comprising the following steps:

[0046] Step 1: After the biochemical sewage enters the biochemical pool 1 for purification, it flows to the sedimentation tank 2 through the delivery pipe 4 for precipitation, and the purified water is discharged. Under the control of the PLC control system, the third valve 310, the fourth valve 311 and the fifth valve 312 are closed, and the first valve 308 and the second valve 309 are opened. The sludge in the sedimentation tank 2 is extracted by the reflux pump 6 and is extracted into the first microorganism inactivation reaction device 3 through the reflux pipe 5. Under the action of the first microorganism inactivation reaction device 3, some microorganisms on the surface of the sludge floccules will be broken or killed under the action of the redox reaction of the alloy material; when the PLC control system detects that the first microorganism inactivation reaction When the outlet pressure gauge of the first microorganism inactivation reactor 3 drops to a certain value, it indicates that the first microorganism inactivation reactor 3 is clogged by impurities in the sludge. Under the control of the PLC control system, the first valve 308 and the second valve 309 are closed, and the third valve 310, the fourth valve 311 and the fifth valve 312 are opened at the same time, and the backwash pump is started to flush the clogged impurities into the sewage tank 305 for discharge. The working time of the first microorganism inactivation reactor 3 is set according to the change in the sludge concentration in the biochemical tank 1. The opening and closing of the first valve 308, the second valve 309 and the third valve 310 are controlled by the PLC control system to realize the activation and deactivation of the first microorganism inactivation reactor 3.

[0047] Step 2: The treated sludge is extracted by the reflux pump 6 and continues to flow back to the biochemical pool 1. The broken and inactivated microbial debris is digested by chemical, physical or biological methods to reduce the output of sludge and achieve in-situ sludge reduction.

[0048] One of the embodiments:

[0049] like Figure 3 As shown, a temporary bacterial cultivation device 7 is added for acclimating and expanding the high-efficiency composite engineering bacteria; the temporary bacterial cultivation device 7 includes a second microorganism inactivation reaction device 701, a temporary bacterial cultivation tank 702 and a switchable self-priming sewage pump device 703; the second microorganism inactivation reaction device 701 has the same structure as the first microorganism inactivation reaction device 3; the temporary bacterial cultivation tank 702 has a built-in plug flow agitator, which is connected to the sedimentation tank 2 and the biochemical tank 1 through the switchable self-priming sewage pump device 703, and is connected to the second microorganism inactivation reaction device 701 through a circulation pump and a pipeline to form an internal circulation system, which continuously performs property modification treatment on the residual sludge, thereby acclimating and expanding the high-efficiency composite engineering bacteria.

[0050] The specific acclimation and expansion process is as follows:

[0051] Step 1: Close the sixth valve 704 and the ninth valve 707, open the seventh valve 705 and the eighth valve 706, and pump a certain amount of sludge from the sedimentation tank 2 to the temporary culture tank 702 through the switchable self-priming sewage pump device 703, and use the remaining sludge as a culture medium for acclimating and expanding the high-efficiency composite engineering bacteria in the temporary culture tank 702. Then, shut down the switchable self-priming sewage pump device 703, and install several push flow agitators in the temporary culture tank 702 to stir the sludge in the temporary culture tank 702; use the circulating pump to modify the sludge in the second microorganism inactivation reaction device 701, and then return it to the temporary culture tank 702. The cycle is repeated so that the sludge in the temporary culture tank 702 is continuously modified by the second microorganism inactivation reaction device 701. The modified sludge is treated to obtain modified sludge. Since the second microbial inactivation reaction device 701 has the function of selectively killing microorganisms in the sludge, the nitrifying and denitrifying bacteria, anaerobic hydrolytic bacteria and other anaerobic bacteria with a slower reproduction rate in the sludge are effectively enriched, thereby significantly improving the biochemical system's ability to reduce total nitrogen and degrade low-biodegradable pollutants. While achieving sludge reduction, the modified sludge can also improve the sewage treatment effect and capacity of the biochemical system. Then, high-efficiency composite engineered bacteria are added to the temporary culture tank 702. The high-efficiency composite engineered bacteria are hydrolytic acidifying bacteria and EM bacteria, and the addition ratio of the two is 6:4. Under the action of the second microbial inactivation reaction device 701, the modified sludge is used as a culture medium to domesticate and expand the high-efficiency composite engineered bacteria to obtain high-efficiency composite engineered bacteria.

[0052] In specific operations, the high-efficiency composite engineered bacteria after domestication and expansion are introduced into the biochemical pool by the following method: a sixth valve 704 is installed between the switchable self-priming sewage pump device 703 and the biochemical pool 1, a seventh valve 705 is installed between the switchable self-priming sewage pump device 703 and the sedimentation pool 2, and an eighth valve 706 and a ninth valve 707 are installed at both ends of the temporary bacteria culture pool 702 respectively; the switchable self-priming sewage pump device 703 realizes the suction of the residual sludge in the sedimentation pool 2 into the temporary bacteria culture pool 702 by switching the sixth valve 704, the seventh valve 705, the eighth valve 706 and the ninth valve 707, and can also introduce the high-efficiency composite engineered bacteria domesticated and expanded in the temporary bacteria culture pool 702 into the biochemical pool 1 for the aforementioned sludge reduction process.

[0053] Taking the daily treatment of 10,000 tons of biochemical sewage as an example, after treatment with the in-situ sludge reduction device of the present invention, the mortality rate of microorganisms in the sludge during the circulation process is 3.97%. When the in-situ sludge reduction device of the present invention is not used for treatment, the increase in microorganisms in the sludge is 5.02%. After calculation, the present invention can reduce the sludge by 3.97% / 5.02*100%=79.08%. In the actual process, only 20% of the increase needs to be processed. This application is basically a one-time investment, with basically no operating costs and no additional energy consumption. The initial one-time investment is approximately 1.5 million yuan, including: 600,000 yuan for the microbial inactivation reactor, 200,000 yuan for high-efficiency composite engineering bacteria, and 700,000 yuan for civil construction and personnel expenses.

[0054] Comparative Example 1

[0055] Conventional existing biochemical sewage treatment methods are used, such as Figure 4 As shown: After the domestic sewage enters the biochemical pool for purification, the purified water is discharged, a part of the incremental sludge is returned to the biochemical pool, and the other part is transferred for disposal (compared with this application, the increment is 100%). About 8 tons of sludge with a moisture content of 80% is produced every day for every 10,000 tons of water. The general cost of treating 1 ton is 300, and the annual cost is 8*300*365=876,000.

[0056] Taking three years as an example, the application cost is 1,500,000 + 8*0.2*300*365*3 = 2,025,600 yuan

[0057] The conventional method processing cost of comparative example 1 is: 876000*3=2628000 yuan.

[0058] It can be seen from this that the cost of this application method can be recovered within three years, which does not include the actual social benefits. The later stage is basically pure cost savings.

[0059] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of the technical features being referred to. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one such feature. In the description of the present invention, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0060] In the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection; direct connection, or indirect connection through an intermediate medium; internal communication between two components, or interaction between two components, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0061] In the present invention, unless otherwise expressly specified or limited, when a first feature is "above" or "below" a second feature, it may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediary. Furthermore, when a first feature is "above," "above," or "above" a second feature, it may mean that the first feature is directly above or diagonally above the second feature, or simply means that the first feature is at a higher level than the second feature. When a first feature is "below," "below," or "below" a second feature, it may mean that the first feature is directly below or diagonally below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0062] Furthermore, those skilled in the art may combine and combine different embodiments or examples and features of different embodiments or examples described in this specification without mutual contradiction.

[0063] Although the embodiments of the present invention have been shown and described above, it will be understood that the above embodiments are illustrative and are not to be construed as limitations on the present invention. A person skilled in the art may change, modify, replace and modify the above embodiments within the scope of the present invention.

Claims

1. A sludge in-situ reduction process for biochemical sewage treatment, implemented based on a sludge in-situ reduction device for biochemical sewage treatment, characterized by: The device comprises a biochemical tank (1), a sedimentation tank (2), and a first microorganism inactivation reaction device (3); a delivery pipe (4) and a return pipe (5) are respectively provided between the biochemical tank (1) and the sedimentation tank (2); the delivery pipe is used to deliver the treated sewage in the biochemical tank (1) to the sedimentation tank (2); the return pipe (5) is used to return the sludge in the sedimentation tank (2) to the biochemical tank (1); a return pump (6) and the first microorganism inactivation reaction device (3) are installed on the return pipe (5); The process includes the following steps: Step 1: After the biochemical wastewater enters the biochemical pool (1) for purification, it flows through the delivery pipe (4) to the sedimentation tank (2) for sedimentation, and the purified water is discharged. The sludge in the sedimentation tank (2) is extracted by the reflux pump (6) and then pumped through the reflux pipe (5) to the first microbial inactivation reaction device (3) to perform cell wall destruction and inactivation treatment on the microorganisms in the sludge; Step 2: The treated sludge is extracted by a reflux pump (6) and continues to flow back into the biochemical pool (1), where the broken and inactivated microbial debris is digested by chemical, physical or biological methods to reduce the output of sludge and achieve in-situ sludge reduction; the biological method includes directly adding high-efficiency composite engineered bacteria and adding high-efficiency composite engineered bacteria after acclimation and expansion; The domestication and expansion of the high-efficiency composite engineering bacteria comprises the following steps: Step 1: Sludge is pumped from the sedimentation tank (2) to the temporary bacteria culture tank (702), the sludge in the temporary bacteria culture tank (702) is treated by the second microorganism inactivation reaction device (701), and then returned to the temporary bacteria culture tank (702), and the cycle is repeated so that the sludge in the temporary bacteria culture tank (702) is continuously modified by the second microorganism inactivation reaction device (701) to obtain modified sludge, and then high-efficiency composite engineered bacteria are added to the temporary bacteria culture tank (702). Under the action of the second microorganism inactivation reaction device (701), the modified sludge is used as a culture medium to acclimate and expand the high-efficiency composite engineered bacteria.

2. The in-situ sludge reduction process for biochemical sewage treatment according to claim 1, characterized in that: The first microorganism inactivation reaction device (3) comprises a PLC control system, a microorganism inactivation reactor (302), a backwashing device (303), a sewage tank (304), a main line pipeline (305), a backwashing pipeline (306) and a bypass pipeline (307); the main line pipeline (305) and the backwashing pipeline (306) are installed at both ends of the microorganism inactivation reactor (302), and the first valve (308) and the second valve (309) are installed at both ends of the main line pipeline (305); the backwashing pipeline (306) is respectively installed with a third valve (310) and a fourth valve (311); the sewage tank (304) is connected to the microorganism inactivation reactor (302) through the backwashing pipeline (306) and the third valve (310); the backwashing device (303) is connected to the microorganism inactivation reactor (302) through the backwashing pipeline (306) and the third valve (310); Four valves (311) are connected to the microorganism inactivation reactor (302) and are controlled by a PLC control system for backwashing and clearing blockages; the bypass pipeline (307) is connected to the main line pipeline (305) in parallel with the microorganism inactivation reactor (302), and a fifth valve (312) is installed on the bypass pipeline (307); the PLC control system is connected to the microorganism inactivation reactor (302), the backwashing device (303), the first valve (308), the second valve (309), the third valve (310), the fourth valve (311) and the fifth valve (312), the pressure gauge and the sludge concentration meter placed in the biochemical tank (1) by pipelines, and controls their use and start and stop; the first microorganism inactivation reaction device (3) is connected to the biochemical tank (1) and the sedimentation tank (2) through the two ends of the main line pipeline (305).

3. The in-situ sludge reduction process for biochemical sewage treatment according to claim 2, characterized in that: The microorganism inactivation reactor (302) is a fluid static device composed of a group of alloy sleeves with a microorganism inactivation function based on a multiple redox potential system. The alloy sleeves have internal rifling, which can change the flow process and turbulence state of the fluid in the tube bundle, prolong and strengthen the contact time and intensity between the microorganisms and the alloy material, and improve the inactivation efficiency of the microorganisms.

4. The in-situ sludge reduction process for biochemical sewage treatment according to claim 3, characterized in that: The alloy sleeve material has the following formula, calculated by weight percentage: zinc: 28%-35%, tin: 4%-7%, nickel: 19%-26%, lanthanum 0.2-0.5%, samarium 0.3-1%, lutetium 1-2%, and the balance is copper.

5. The in-situ sludge reduction process for biochemical sewage treatment according to claim 2, characterized in that: The backwash device (303) closes the first valve (308) and the second valve (309) through the PLC control system according to the pressure gauge signal, and opens the third valve (310), the fourth valve (311) and the fifth valve (312) and the sewage pump to remove impurities that block the microorganism inactivation reactor (302).

6. The in-situ sludge reduction process for biochemical sewage treatment according to claim 1, characterized in that: A temporary bacterial culture device (7) is provided for acclimating and expanding the high-efficiency composite engineering bacteria; the temporary bacterial culture device (7) comprises a second microorganism inactivation reaction device (701), a temporary bacterial culture tank (702) and a switchable self-priming sewage pump device (703); the second microorganism inactivation reaction device (701) and the first microorganism inactivation reaction device (3) have the same structure; the temporary bacterial culture tank (702) is equipped with a plug flow agitator, is connected to the sedimentation tank (2) and the biochemical tank (1) through the switchable self-priming sewage pump device (703), and is connected to the second microorganism inactivation reaction device (701) through a circulation pump and a pipeline to form an internal circulation system, which continuously performs property modification treatment on the residual sludge, thereby acclimating and expanding the high-efficiency composite engineering bacteria.

7. The in-situ sludge reduction process for biochemical sewage treatment according to claim 6, characterized in that: A sixth valve (704) is installed between the switchable self-priming sewage pump device (703) and the biochemical tank (1), a seventh valve (705) is installed between the switchable self-priming sewage pump device (703) and the sedimentation tank (2), and an eighth valve (706) and a ninth valve (707) are installed at both ends of the temporary bacterial culture tank (702). The switchable self-priming sewage pump device (703) can pump the residual sludge in the sedimentation tank (2) into the temporary bacterial culture tank (702) by switching the sixth valve (704), the seventh valve (705), the eighth valve (706) and the ninth valve (707), and can also introduce the high-efficiency composite engineered bacteria domesticated and expanded in the temporary bacterial culture tank (702) into the biochemical tank (1).

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