An autotrophic denitrification multi-cell control device and wastewater denitrification method

Abstract

The application discloses a kind of autotrophic denitrification multi-cell regulation device and sewage denitrification method, the multi-cell regulation device includes multiple autotrophic denitrification pools in box (1), clear water pool (2), pipeline (3) and equipment room (7), autotrophic denitrification pool is installed in the box by parallel mode between each other, the denitrification process of each autotrophic denitrification pool is independent of each other, each has independently inlet and outlet pipe, each inlet and outlet pipe is connected with PLC controller, so that autotrophic denitrification pool can be automatically regulated according to sewage treatment capacity, while the number of autotrophic denitrification pool can be adjusted according to the temperature of sewage to be treated, give the device stronger sewage treatment adaptability, reduce sewage treatment cost, while improve denitrification effect and denitrification efficiency, with good application prospect.

Description

Technical Field

[0001] This invention relates to the field of water pollution treatment, specifically to a multi-compartment control device and a denitrification method using the device. Background Technology

[0002] Nitrogen and phosphorus pollution in water bodies is a major cause of eutrophication, especially in rural areas of my country where the volume of wastewater discharged from domestic and agricultural activities is enormous. Rural wastewater mainly includes wastewater from agricultural production, excrement, animal husbandry, and landfill leachate. Due to the extensive use of chemical fertilizers and the discharge of large amounts of human and animal excrement, rural wastewater contains a large amount of nitrogenous pollutants, such as ammonia nitrogen and nitrate nitrogen. Nitrogenous pollutants are among the main pollutants that pollute surface water and groundwater, and are also the "culprit" of eutrophication of surface water bodies.

[0003] However, rural areas in my country are relatively underdeveloped and have limited technology. The vast majority of sewage is directly discharged into lakes and rivers or used for land infiltration irrigation, causing extensive pollution of water bodies and soil in rural areas and seriously threatening the rural living environment.

[0004] The current method for removing nitrogen pollution from wastewater is mainly heterotrophic denitrification technology, which requires the introduction of carbon sources into the water body, resulting in high economic costs, operational difficulties, and a high risk of secondary pollution. Summary of the Invention

[0005] Based on the aforementioned technical background, the inventors have made significant progress and provided an autotrophic denitrification multi-compartment control device and a wastewater denitrification method. The multi-compartment control device includes a housing 1 and multiple autotrophic denitrification tanks. These tanks are installed in parallel within the housing. The denitrification process of each autotrophic denitrification tank is independent, with each tank having its own independent inlet pipe, air inlet pipe, outlet pipe, and air outlet pipe, all connected to a PLC controller. This multi-compartment control device can automatically adjust the inlet pipe, air inlet pipe, outlet pipe, and air outlet pipe of each autotrophic denitrification tank according to the wastewater treatment volume. This allows the autotrophic denitrification tanks in operation to automatically adjust according to the wastewater treatment volume and temperature, adaptively adjusting the hydraulic retention time and the number of activated sub-units. This gives the device stronger wastewater treatment adaptability, improves denitrification effect and efficiency, and reduces wastewater treatment costs, thus completing this invention.

[0006] The first aspect of the present invention is to provide an autotrophic denitrification multi-compartment control device. Specifically, the multi-compartment control device includes multiple autotrophic denitrification tanks, a clear water tank 2, a pipe room 3 and an equipment room 7 located in a housing 1. The autotrophic denitrification tanks are installed in the housing 1 in parallel.

[0007] The pipeline room 3 and multiple autotrophic denitrification tanks are located between the equipment room 7 and the clear water tank 2, with the autotrophic denitrification tanks located between the pipeline room 3 and the equipment room 7;

[0008] The main inlet pipe 807 is installed in equipment room 7, and the main inlet pipe 807 is located between the autotrophic denitrification tank and the inlet pump.

[0009] A second aspect of the present invention is to provide a method for denitrification of wastewater using the multi-compartment control device described in the first aspect of the present invention, wherein the wastewater to be treated is fed into the multi-compartment control device for wastewater treatment. Attached Figure Description

[0010] Figure 1 This diagram shows a top view of a multi-compartment control device according to a preferred embodiment of the present invention.

[0011] Figure 2 A cross-sectional schematic diagram of an autotrophic denitrification tank according to a preferred embodiment of the present invention is shown;

[0012] Figure 3 A perspective view of three sub-units in a multi-cell control device according to a preferred embodiment of the present invention is shown.

[0013] Figure 4 The diagram shows the denitrification efficiency curve during the operation of the multi-grid control device in Example 1.

[0014] Explanation of icon numbers

[0015] 1-Box;

[0016] 2-Clear pool;

[0017] 3-Pipe room;

[0018] 4-Autotrophic denitrification tank one;

[0019] 5-Autotrophic denitrification tank two;

[0020] 6-Autotrophic denitrification tank three;

[0021] 7-Equipment Room;

[0022] 101 - First partition;

[0023] 102 - Second partition;

[0024] 103 - Third partition;

[0025] 104 - Fourth partition;

[0026] 105 - Fifth partition;

[0027] 201-Backwash water pump;

[0028] 202-Overflow weir of clear water pool;

[0029] 203 - Main water outlet pipe;

[0030] 301-Outlet Pipe 1;

[0031] 302 - Outlet Pipe 2;

[0032] 303-Outlet pipe three;

[0033] 304 - Backwash main outlet pipe;

[0034] 305-Backwash outlet pipe one;

[0035] 306-Backwash outlet pipe two;

[0036] 307-Backwash outlet pipe three;

[0037] 701 - Backwash fan;

[0038] 702 - Backwash water pump;

[0039] 703-Backwash Main Inlet Pipe

[0040] 804 - Inlet Pipe 1;

[0041] 805-Inlet Pipe 2;

[0042] 806-Inlet Pipe Three;

[0043] 807 - Main water inlet pipe;

[0044] 808 - Backwashing Channel;

[0045] 901 - Main intake manifold;

[0046] 902 - Intake Pipe 1;

[0047] 903 - Intake pipe two;

[0048] 904 - Intake pipe three;

[0049] 905-Overflow pipe one;

[0050] 906-Overflow pipe two;

[0051] 907-Overflow pipe three. Detailed Implementation

[0052] The present invention will now be described in detail, and its features and advantages will become clearer and more apparent from these descriptions.

[0053] The first aspect of this invention is to provide an autotrophic denitrification multi-compartment control device. This device includes multiple autotrophic denitrification tanks, a clear water tank 2, a pipe room 3, and an equipment room 7, all located within a housing 1. The autotrophic denitrification tanks are installed in parallel within the housing. The denitrification process of each autotrophic denitrification tank is independent. During wastewater treatment, the parallel connection allows for more independent operation between the individual tanks. The device can adjust the number of autotrophic denitrification tanks in operation according to the wastewater treatment volume, making the device more adaptable to wastewater treatment and improving its denitrification effect and efficiency.

[0054] The pipeline room 3 is located between the equipment room 7 and the clear water tank 2, and the autotrophic denitrification tank is located between the pipeline room 3 and the equipment room 7. The pipeline room 3 and the clear water tank 2 are separated by a fifth partition 105, the autotrophic denitrification tank and the pipeline room 3 are separated by a first partition 101, and the equipment room 7 and the autotrophic denitrification tank are separated by a fourth partition 104.

[0055] In this invention, the main inlet pipe 807 is installed in the equipment room 7. The main inlet pipe 807 is located between the autotrophic denitrification tank and the inlet pump. The inlet pump pumps the front-end sewage into the autotrophic denitrification tank for denitrification treatment.

[0056] An outlet pipe is installed in pipe room 3. The outlet pipe is installed between clear water tank 2 and autotrophic denitrification tank. The wastewater treated by autotrophic denitrification tank is collected in clear water tank 2 through the outlet pipe.

[0057] The multi-compartment control device also includes a main water outlet pipe 203, which is located above the clear water tank 2.

[0058] After treatment, the water passes through the sedimentation and separation process in the clear water tank 2, leaving suspended solids and large molecules in the multi-compartment control device. Finally, the water is discharged from the multi-compartment control device through the main outlet pipe 203 above the clear water tank 2, thus completing the wastewater purification process.

[0059] The clear water pool includes a clear water pool overflow weir 202, which is located at the top of the clear water pool 2, and the main outlet pipe 203 is installed on the side wall of the clear water pool overflow weir 202.

[0060] Each autotrophic denitrification tank is equipped with an outlet pipe and an inlet pipe, with the number of inlet pipes and air inlet pipes being the same as the number of autotrophic denitrification tanks. The inlet pipe is installed in equipment room 7, located between the main inlet pipe 807 and the autotrophic denitrification tank. The outlet pipe is installed in pipe room 3, located between the autotrophic denitrification tank and the clear water tank 2.

[0061] Solenoid valves are installed on each inlet and outlet pipe. The solenoid valves are connected to a PLC controller to control the opening and closing of the inlet, air inlet and outlet pipes of the self-aeration denitrification tanks. This allows the inlet pipes to open and close according to the amount of wastewater treated, and controls the number of self-aeration denitrification tanks in operation. The multi-compartment control device can be adaptively adjusted according to the amount of wastewater treated.

[0062] The number of autotrophic denitrification tanks is 2 to 10, preferably 2 to 6, and more preferably 3.

[0063] According to a preferred embodiment of the present invention, the multi-cell control device includes an autotrophic denitrification tank 4, an autotrophic denitrification tank 5, and an autotrophic denitrification tank 6. The autotrophic denitrification tank 4 and the autotrophic denitrification tank 5 are separated by a second partition 102, and the autotrophic denitrification tank 5 and the autotrophic denitrification tank 6 are separated by a third partition 103.

[0064] Preferably, the water inlet pipe includes a first water inlet pipe 804, a second water inlet pipe 805, and a third water inlet pipe 806. The first water inlet pipe 804 is located between the first autotrophic denitrification tank 4 and the main water inlet pipe 807, the second water inlet pipe 805 is located between the second autotrophic denitrification tank 5 and the main water inlet pipe 807, and the third water inlet pipe 806 is located between the third autotrophic denitrification tank 6 and the main water inlet pipe 807.

[0065] Solenoid valves are installed on each inlet pipe to control the opening of each autotrophic denitrification tank. If the wastewater treatment volume is large, the solenoid valves of multiple inlet pipes can be opened to allow multiple autotrophic denitrification tanks to open simultaneously for wastewater denitrification. If the wastewater treatment volume is small, only one or two inlet pipe valves need to be opened for wastewater denitrification. This increases the controllability of the multi-compartment control device described in this application for the wastewater treatment volume, and allows for adaptive adjustments based on the size of the wastewater treatment volume.

[0066] The effluent pipes include effluent pipe 301 between autotrophic denitrification tank 4 and clear water tank 2, effluent pipe 302 between autotrophic denitrification tank 5 and clear water tank 2, and effluent pipe 303 between autotrophic denitrification tank 6 and clear water tank 2. Figure 1 As shown.

[0067] An outlet pipe is installed between each autotrophic denitrification tank and the clear water tank to ensure that the autotrophic denitrification tanks are connected in parallel, so that the wastewater denitrification process of each autotrophic denitrification tank is independent of each other. The number of autotrophic denitrification tanks to be started can be determined according to the actual amount of wastewater to be treated. If the amount of wastewater to be treated is large, multiple autotrophic denitrification tanks can be started. If the amount of wastewater to be treated is small, only one needs to be started to complete the process, effectively improving the wastewater treatment efficiency.

[0068] According to a further preferred embodiment of the present invention, each of the denitrification tanks includes a support layer, a filter media layer, a water distribution pipe, and an air distribution pipe. The support layer and the filter media layer are horizontally laid above the water distribution pipe and the air distribution pipe, with the filter media layer located above the support layer. Figure 2 As shown.

[0069] The support layer includes a filter brick support layer and a pebble support layer. The pebble support layer is located above the filter brick support layer, and the filter bricks and filter heads are evenly arranged below the pebble support layer to achieve uniform water intake. The water distribution pipe is connected to the water inlet pipe, and the air distribution pipe is connected to the air inlet pipe.

[0070] During operation, wastewater pumped in by the inlet pump flows upward through the filter brick support layer, the pebble support layer, and the filter media layer. Under the action of the microbial film in the filter media layer, denitrification occurs. The filter media adsorbs nitrate ions from the wastewater, achieving nitrogen and phosphorus removal. The wastewater then flows into the clear water tank through the overflow weir at the top of the autotrophic denitrification tank via the outlet pipe. Figure 2 As shown.

[0071] The filter media layer includes sulfur-based functional materials and sulfur-autotrophic denitrifying bacteria.

[0072] In a preferred embodiment, the sulfur-based functional material is, for example, a solid functional material synthesized from single elements of sulfur and iron, or from sulfur-based and iron-based composite elements, such as elemental sulfur, elemental iron, pyrite, siderite, magnetite, elemental sulfur-elemental iron, elemental sulfur-pyrite, elemental sulfur-siderite, elemental sulfur-magnetite, elemental sulfur-calcium carbonate, elemental sulfur-ferrous carbonate, etc. Commonly used materials in the art can be used for these sulfur-based functional materials, and there are no particular limitations.

[0073] The particle size of the sulfur-based functional material is 1–20 mm, preferably 2–15 mm.

[0074] According to a preferred embodiment of the present invention, a backwash water pump 702 is also installed in the equipment room 7. The backwash water pump 702 is connected to the backwash main water inlet pipe 703, and the backwash main water inlet pipe 703 is connected to each backwash water inlet pipe, so as to backwash each denitrification tank.

[0075] By installing a backwash water pump, caking of the packing material in the denitrification tank can be avoided, keeping the porosity of the packing material within a certain range, which is beneficial to improving the denitrification effect.

[0076] Preferably, the backwash water pump 702 of the present invention is connected to the overflow weir 202 of the clear water tank through the backwash channel 808, that is, the water used for backwashing comes from the water after denitrification treatment. The dissolved oxygen content in the water after ammonia removal treatment is low. Using it as backwash water can reduce the inhibitory effect of dissolved oxygen on the rate of sulfur autotrophic denitrification, prevent packing caking, and improve the denitrification effect and efficiency of sewage.

[0077] Because there are many impurities and pollutants in the water after backwashing, the water after backwashing flows out of the backwash outlet pipe into the multi-compartment control device. The backwash main outlet pipe 304 is located in the pipe room 3. The backwash main outlet pipe is connected to each backwash outlet pipe. The backwash outlet pipe is located between the autotrophic denitrification tank and the backwash main outlet pipe 304. A valve is installed on the backwash outlet pipe. Only when backwashing is performed will the solenoid valve on the backwash outlet pipe open, allowing the backwashed water to flow out from the backwash main outlet pipe 304.

[0078] Preferably, the backwash outlet pipe includes backwash outlet pipe one 305, backwash outlet pipe two 306, and backwash outlet pipe three 307. Backwash outlet pipe one 305 is located between autotrophic denitrification tank one 4 and backwash main outlet pipe 304, backwash outlet pipe two 306 is located between autotrophic denitrification tank two 5 and backwash main outlet pipe 304, and backwash outlet pipe three 307 is located between autotrophic denitrification tank three 6 and backwash main outlet pipe 304.

[0079] The backwash inlet pipes include Backwash Inlet Pipe 1, located between Autotrophic Denitrification Tank 1 4 and Backwash Main Inlet Pipe 703; Backwash Inlet Pipe 2, located between Autotrophic Denitrification Tank 2 5 and Backwash Main Inlet Pipe 703; and Backwash Inlet Pipe 3, located between Autotrophic Denitrification Tank 3 6 and Backwash Main Inlet Pipe 703. Each backwash inlet pipe is equipped with a solenoid valve, which can control which autotrophic denitrification tank is backwashed. The solenoid valves of each backwash inlet pipe are installed between the autotrophic denitrification tank and the backwash main inlet pipe 703.

[0080] According to a further preferred embodiment of the present invention, a main air inlet pipe 901 and a backwash fan 701 are also installed in the equipment room 7. The main air inlet pipe 901 is located between the autotrophic denitrification tank and the backwash fan 701. Gas is pumped into the main air inlet pipe 901 via the backwash fan 701 and then flows into the autotrophic denitrification tank through the main air inlet pipe 901. The arrangement of the air inlet pipe and the backwash fan allows the device to also perform air washing. When the backwashing system and the air washing system are turned on simultaneously, the device can perform combined air-water washing.

[0081] The main air inlet pipe 901 preferably enters the autotrophic denitrification tank through the air inlet pipe, which is located between the main air inlet pipe 901 and the autotrophic denitrification tank.

[0082] The air inlet pipe includes air inlet pipe one 902, air inlet pipe two 903 and air inlet pipe three 904. Air inlet pipe one 902 is located between the autotrophic denitrification tank and the main air inlet pipe 901, air inlet pipe two 903 is located between the autotrophic denitrification tank and the main air inlet pipe 901, and air inlet pipe three 904 is located between the autotrophic denitrification tank and the main air inlet pipe 901.

[0083] Solenoid valves are installed on each air inlet pipe. The opening and closing of the solenoid valves on the air inlet pipes are controlled according to the amount of sewage treated. When the amount of sewage treated is large, multiple autotrophic denitrification tanks need to be opened at the same time to denitrify the sewage. At this time, the valves on multiple air inlet pipes are opened so that multiple autotrophic denitrification tanks can work at the same time.

[0084] An overflow pipe is also installed in the pipe room 3. The overflow pipe is located between the autotrophic denitrification tank and the clear water tank 2, and is connected to the autotrophic denitrification tank and the clear water tank. The overflow pipe includes overflow pipe one 905, overflow pipe two 906 and overflow pipe three 907.

[0085] Overflow pipe 1 (905) is located between autotrophic denitrification tank 1 (4) and clear water tank 2; overflow pipe 2 (906) is located between autotrophic denitrification tank 2 (5) and clear water tank 2; and overflow pipe 3 (907) is located between autotrophic denitrification tank 3 (6) and clear water tank 2.

[0086] When the water level in the autotrophic denitrification tank is too high, the denitrified clear water flows into the clear water tank 2 through the overflow pipe.

[0087] A second aspect of the present invention is to provide a method for denitrification of wastewater using the multi-compartment control device described in the first aspect of the present invention, wherein the wastewater to be treated is fed into the multi-compartment control device for wastewater treatment.

[0088] In a preferred embodiment, the number of autotrophic denitrification tanks (i.e., sub-units) activated in the multi-compartment control device and the residence time of the wastewater in the autotrophic denitrification tanks are adjusted according to the nitrate content in the wastewater and the temperature of the wastewater to be treated. If the nitrate concentration is high, multiple sub-units can be activated and the wastewater residence time can be extended. If the nitrate concentration is low, fewer sub-units can be activated and the wastewater residence time can be shortened.

[0089] By adjusting the number of open sub-units, the concentration of nitrate after wastewater treatment can be reduced, thereby improving the wastewater treatment effect. At the same time, the consumption of packing material can be reduced. Compared with autotrophic denitrification, the operating cost is reduced, the problem of excessive denitrification is avoided, and the economic efficiency is improved.

[0090] In a further preferred embodiment, when the water temperature is 18-21℃, the denitrification efficiency of the multi-cell control device is high, and it can basically remove all nitrate nitrogen. Considering the consumption of packing material, when one sub-unit is turned on, the EBCT (water retention time) is shortened to 0.1-1h, preferably 0.3-0.7h, and more preferably 0.5h. Under these conditions, compared with turning on three or two sub-units, the nitrogen removal efficiency of multiple control devices decreases. The highest TN concentration in the effluent is 7.0mg / L, and the average TN removal rate is about 8.1mg / L. At this point, the effluent can still meet the discharge standards, but the consumption of packing material is greatly reduced.

[0091] When the water temperature is 14–17°C, two sub-units are activated, and the EBCT time for each sub-unit is extended to 0.5–1.5 h, preferably 0.8–1.2 h, and more preferably 1 h.

[0092] If the temperature drops further, such as when the water temperature is below 14°C, all three sub-units should be activated simultaneously, with the EBCT of each sub-unit extended to 1–3 hours, preferably 1.2–2 hours, and more preferably 1.5 hours.

[0093] Experiments revealed that denitrification efficiency decreases with decreasing temperature. Activating more sub-units and extending the EBCT (Excessive Electron Tube Time) can improve wastewater denitrification efficiency while reducing packing material consumption and further lowering operating costs. Within this temperature range, activating three sub-units and extending the EBCT resulted in a maximum nitrate nitrogen concentration of approximately 9.92 mg / L, a minimum nitrate nitrogen concentration of approximately 8.81 mg / L, and an average denitrification rate of approximately 5.6 mg / L, achieving the required effluent quality. This demonstrates that even with all three sub-units activated at lower temperatures, effluent quality remains compliant. Furthermore, it was found that higher water temperatures lead to greater packing material consumption and increased costs. Activating three sub-units at lower temperatures reduces packing material consumption to 25% of the total packing material, effectively lowering costs.

[0094] The beneficial effects of this invention are as follows:

[0095] (1) The multi-grid control device of the present invention uses multiple autotrophic denitrification tanks connected in parallel to perform denitrification treatment. Each autotrophic denitrification tank has its own independent inlet pipe and outlet pipe, which can be automatically adjusted according to the sewage treatment volume, so as to achieve efficient denitrification and phosphorus removal of sewage, with good denitrification effect and high efficiency.

[0096] (2) The multi-grid control device of the present invention is simple to operate, does not require an external carbon source during the processing, avoids secondary pollution, and has a high cost performance.

[0097] (3) By introducing a backwash water pump and a backwash water inlet pipe, and by connecting the denitrified clean water to the backwash water inlet pipe for backwashing, the present invention effectively reduces the caking of filter media in the autotrophic denitrification tank and improves the denitrification treatment effect.

[0098] (4) By introducing a backwash fan and an air inlet pipe, the present invention enables the device to have the function of air-water combined washing;

[0099] (5) The multi-compartment control device of the present invention can flexibly adjust the opening and stopping of the sub-units in the filter bed according to the changes in water temperature every day while maintaining a stable influent flow rate, thereby reducing the denitrification cost while ensuring the denitrification effect.

[0100] (6) The multi-grid control device and denitrification method described in this invention can effectively deal with the problem of low-temperature effluent water quality exceeding the standard caused by temperature changes, avoid excessive denitrification, and at the same time minimize the consumption of filter media. The filter media is basically not ineffectively consumed, reducing unnecessary loss of filter media, reducing costs, and is economical and practical. It can operate stably for a long time under temperature change conditions and can simultaneously meet the requirements of economy and good denitrification effect.

[0101] (7) The EBCT of each subunit of the multi-grid control device described in this invention is adjusted from 5h to 1.5h to complete the start-up of the multi-grid control device.

[0102] Example

[0103] The present invention is further illustrated by specific examples below. These embodiments are only for illustrating the present invention and are not intended to limit the scope of the present invention.

[0104] Example 1

[0105] Adopting such Figure 1 The multi-compartment control device shown is used for wastewater denitrification treatment. The main material of this device is stainless steel, and its dimensions are 7m × 3m × 3m. The device includes three autotrophic denitrification tanks (4, 5, 6, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 10, 11, 11, 12, 13, 19 ... The equipment room 7 and the pipe room 3 are separated from the clear water tank 2 by a fifth partition 105; the autotrophic denitrification tank and the pipe room 3 are separated by a first partition 101; the equipment room 7 and the autotrophic denitrification tank are separated by a fourth partition 104; autotrophic denitrification tank 1 4 and autotrophic denitrification tank 2 5 are separated by a second partition 102; and autotrophic denitrification tank 2 5 and autotrophic denitrification tank 3 6 are separated by a third partition 103. The effective volume of each autotrophic denitrification tank is 2.83 m³. 3 .

[0106] The main inlet pipe 807 is installed in the equipment room 7. The main inlet pipe 807 is located between the autotrophic denitrification tank and the inlet pump. Each autotrophic denitrification tank is equipped with an outlet pipe and an inlet pipe. The inlet pipe is installed in the equipment room 7. The inlet pipe is located between the main inlet pipe 807 and the autotrophic denitrification tank. The inlet pipe includes inlet pipe one 804, inlet pipe two 805 and inlet pipe three 806. Inlet pipe one 804 is located between autotrophic denitrification tank one 4 and the main inlet pipe 807. Inlet pipe two 805 is located between autotrophic denitrification tank two 5 and the main inlet pipe 807. Inlet pipe three 806 is located between autotrophic denitrification tank three 6 and the main inlet pipe 807. The main outlet pipe 203 is located above the clear water tank 2. The clear water tank includes the clear water tank overflow weir 202, which is located at the top of the clear water tank 2. The main outlet pipe 203 is installed on the side wall of the clear water tank overflow weir 202. The outlet pipe is installed in the pipe room 3, located between the autotrophic denitrification tank and the clear water tank 2. The outlet pipe includes the outlet pipe 301 between the autotrophic denitrification tank 4 and the clear water tank 2, the outlet pipe 302 between the autotrophic denitrification tank 5 and the clear water tank 2, and the outlet pipe 303 between the autotrophic denitrification tank 6 and the clear water tank. A solenoid valve is installed on each inlet pipe and outlet pipe. The solenoid valve is connected to the PLC controller. A backwash water pump 702 is also installed in equipment room 7. The backwash water pump 702 is connected to the main backwash inlet pipe 703, which in turn is connected to each of the other backwash inlet pipes. The backwash water pump 702 is connected to the overflow weir 202 of the clear water tank via a backwash channel 808. The main backwash outlet pipe 304 is located in pipe room 3 and is connected to each of the other backwash outlet pipes. The backwash outlet pipes are located between the autotrophic denitrification tank and the main backwash outlet pipe 304. The backwash outlet pipes include backwash outlet pipe one 305, backwash outlet pipe two 306, and backwash outlet pipe three 307. Backwash outlet pipe one 305 is located between the autotrophic denitrification tank one 4 and the main backwash outlet pipe one 307. Between water pipes 304, backwash outlet pipe two 306 is located between autotrophic denitrification tank two 5 and backwash main outlet pipe 304, and backwash outlet pipe three 307 is located between autotrophic denitrification tank three 6 and backwash main outlet pipe 304. Valves are installed on each backwash outlet pipe. Backwash inlet pipes include backwash inlet pipe one located between autotrophic denitrification tank one 4 and backwash main inlet pipe 703, backwash inlet pipe two located between autotrophic denitrification tank two 5 and backwash main inlet pipe 703, and backwash inlet pipe three located between autotrophic denitrification tank three 6 and backwash main inlet pipe 703. Solenoid valves for each backwash inlet pipe are installed between the autotrophic denitrification tank and backwash main inlet pipe 703. The equipment room 7 is also equipped with a main air inlet pipe 901 and a backwash fan 701. The main air inlet pipe 901 is located between the autotrophic denitrification tank and the backwash fan 701. The air inlet pipes include air inlet pipe one 902, air inlet pipe two 903 and air inlet pipe three 904. Air inlet pipe one 902 is located between the autotrophic denitrification tank and the main air inlet pipe 901. Air inlet pipe two 903 is located between the autotrophic denitrification tank and the main air inlet pipe 901. Air inlet pipe three 904 is located between the autotrophic denitrification tank and the main air inlet pipe 901. Solenoid valves are installed on each air inlet pipe.An overflow pipe is also installed in pipe room 3. The overflow pipe is located between the autotrophic denitrification tank and the clear water tank 2. The overflow pipe includes overflow pipe 1 905, overflow pipe 2 906 and overflow pipe 3 907. Overflow pipe 1 905 is located between autotrophic denitrification tank 1 4 and clear water tank 2. Overflow pipe 2 906 is located between autotrophic denitrification tank 2 5 and clear water tank 2. Overflow pipe 3 907 is located between autotrophic denitrification tank 3 6 and clear water tank 2.

[0107] Each autotrophic denitrification tank includes a support layer, a filter media layer, a water distribution pipe, and an air distribution pipe. The support layer and the filter media layer are laid horizontally above the water distribution pipe and the air distribution pipe. The filter media layer is located above the support layer and includes elemental sulfur-siderite composite material and sulfur autotrophic denitrifying bacteria. The particle size of the elemental sulfur-siderite composite material is 2-15 mm. The support layer includes a filter brick support layer and a pebble support layer. The pebble support layer is located above the filter brick support layer. The height of the filter media layer is 1.4 m, the height of the pebble support layer is 0.2 m, and the height of the filter brick support layer is 0.3 m.

[0108] Inoculate sludge into the multi-cell control device (inoculation concentration of 500–1000 g MLSS / m³). 3 The influent is the actual effluent from conventional rural domestic sewage treated by the MBBR equipment. The sewage to be treated is then introduced into the device at a flow rate of 200 m³. 3 The wastewater to be treated had a nitrate content of 14.2–18.1 mg / L and a pH value of 7.4–7.9. During the startup of the multi-compartment control device, three autotrophic denitrification tanks were simultaneously activated. The initial EBCT was controlled at 5 hours, and the EBCT was gradually shortened to 1.5 hours based on the denitrification effect. After 5–7 days in the autotrophic denitrification tanks, the effluent from each autotrophic denitrification tank achieved stable denitrification and met the standard (TN < 10 mg / L), thus completing the startup. Subsequently, while maintaining a stable influent flow rate, the startup and shutdown of each autotrophic denitrification tank were flexibly adjusted according to changes in water temperature.

[0109] The specific method for adjusting wastewater denitrification using a multi-compartment control device based on water temperature changes is as follows: When the water temperature is 18–21℃, open any one of the autotrophic denitrification tanks in the multi-compartment control device and control the EBCT (hydraulic retention time) of the autotrophic denitrification tank to 0.5h; when the influent temperature is 14–17℃, open any two of the autotrophic denitrification tanks in the multi-compartment control device and control the EBCT of the two autotrophic denitrification tanks to 1h; when the influent temperature is 9–13℃, open all three autotrophic denitrification tanks in the multi-compartment control device and control the EBCT of all three autotrophic denitrification tanks to 1.5h. Backwashing is performed during the wastewater denitrification process, with a backwashing frequency of once a day.

[0110] The denitrification efficiency during the operation of the multi-grid control device is as follows: Figure 4 As shown, from Figure 4As can be seen, when the influent temperature is 18–21℃, the nitrate nitrogen content after treatment is 4.5–10 mg / L; when the influent temperature is 14–17℃, the nitrate nitrogen content after treatment is 5.4–10 mg / L; and when the influent temperature is 9–13℃, the nitrate nitrogen content after treatment is 4.6–10 mg / L. This indicates that the multi-compartment control device and denitrification method described in this invention can efficiently remove nitrogen from wastewater, and the nitrate nitrogen content of the wastewater after denitrification treatment is 4.5–10 mg / L.

[0111] Comparative Example

[0112] Wastewater denitrification was carried out in a manner similar to that in Example 1, except that the wastewater denitrification method was not adjusted according to changes in water temperature, and three autotrophic denitrification tanks were started, with an EBCT time of 1.5 hours for each tank.

[0113] Experimental Example

[0114] Experiment Example 1: Packing Consumption Test

[0115] The packing consumption during the denitrification process in Example 1 and Comparative Example 1 was tested over 180 days, and the test results are shown in Table 1. The specific test process is as follows: The height change of the top 5 points of the packing in the multi-compartment control device was measured and calculated with reference to Equations (1)-(4).

[0116] Δh=h0-h t Equation (1)

[0117] ΔN=(N0-N t Equation (2) is: )*180d*Q / 1000

[0118] S = a * b (Equation 3)

[0119] m / ΔN=S*ρ*Δh / ΔN Formula (4);

[0120] In equations (1)-(4), Δh is the difference in packing height, h0 is the initial height of the packing, and h t ΔN is the height of the packing material after 180 days, ΔN is the total denitrification rate (kg) at 180 days, and Q is the influent flow rate (200 m³ / h). 3 / d), ρ is the packing density 1.22 (g / cm³) 3 ), a and b are the length and width of the autotrophic denitrification tank, respectively, N0 is the influent TN concentration, N t It refers to the TN concentration in the effluent.

[0121] Table 1

[0122]

[0123]

[0124] As can be seen from Table 1, the comparative example, which did not use this control method, experienced excessive denitrification, leading to excessive consumption of the packing material. The packing material consumption in Example 1 was reduced by 41.44% compared to the comparative example, indicating that the amount of packing material consumed using the multi-cell control device and denitrification method described in this application is less than that consumed in the comparative example, effectively reducing operating costs.

[0125] In the description of this invention, it should be noted that the terms "upper," "lower," "inner," "outer," "front," and "rear," etc., indicate the orientation or positional relationship based on the orientation or positional relationship in the working state of this invention, and are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this invention. Furthermore, the terms "first," "second," "third," and "fourth" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0126] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0127] The present invention has been described above with reference to preferred embodiments; however, these embodiments are merely exemplary and illustrative. Various substitutions and modifications can be made to the present invention based on these embodiments, all of which fall within the scope of protection of the present invention.

Claims

1. An autotrophic denitrification multi-step regulation device, characterized in that, The multi-cell regulation device comprises multiple autotrophic denitrification tanks, a clear water tank (2), a pipeline room (3) and an equipment room (7) in a box (1), and the autotrophic denitrification tanks are installed in the box (1) in parallel; The pipeline room (3) and the multiple autotrophic denitrification tanks are located between the equipment room (7) and the clear water tank (2), and the autotrophic denitrification tanks are located between the pipeline room (3) and the equipment room (7); A total water inlet pipe (807) is installed in the equipment room (7), and the total water inlet pipe (807) is located between the autotrophic denitrification tanks and a water inlet pump; A backwashing water pump (702) is also installed in the equipment room (7), the backwashing water pump (702) is connected with a backwashing total water inlet pipe (703), and the backwashing total water inlet pipe (703) is connected with each backwashing water inlet pipe; The clear water tank comprises a clear water tank overflow weir (202) located at the uppermost part of the clear water tank (2); The backwashing water pump (702) is communicated with the clear water tank overflow weir through a backwashing channel (808); A backwashing total water outlet pipe (304) is located in the pipeline room (3), the backwashing total water outlet pipe is connected with each backwashing water outlet pipe, the backwashing water outlet pipe is located between the autotrophic denitrification tank and the backwashing total water outlet pipe (304), and an electromagnetic valve is installed on the backwashing water outlet pipe; The backwashing water outlet pipe comprises a backwashing water outlet pipe one (305) located between the autotrophic denitrification tank one (4) and the backwashing total water outlet pipe (304), a backwashing water outlet pipe two (306) located between the autotrophic denitrification tank two (5) and the backwashing total water outlet pipe (304), and a backwashing water outlet pipe three (307) located between the autotrophic denitrification tank three (6) and the backwashing total water outlet pipe (304); Each autotrophic denitrification tank comprises a supporting layer, a filter material layer, a water distribution pipe and a gas distribution pipe, the water distribution pipe and the gas distribution pipe are horizontally laid above the supporting layer and the filter material layer, and the filter material layer is located above the supporting layer, The supporting layer comprises a filter brick supporting layer and a cobblestone supporting layer, the cobblestone supporting layer is located above the filter brick supporting layer, filter bricks and filter heads are uniformly arranged below the cobblestone supporting layer, uniform water inlet is realized, the water distribution pipe is connected with a water inlet pipe, and the gas distribution pipe is connected with an air inlet pipe.

2. The multi-cell regulation device according to claim 1, wherein Each autotrophic denitrification tank is provided with a water outlet pipe and a water inlet pipe, the number of the water inlet pipes and the water outlet pipes is the same as the number of the autotrophic denitrification tanks, and an electromagnetic valve is installed on each water inlet pipe and water outlet pipe; The water inlet pipe is installed in the equipment room (7) and located between the total water inlet pipe (807) and the autotrophic denitrification tank, and the water outlet pipe is installed in the pipeline room (3) and located between the autotrophic denitrification tank and the clear water tank (2).

3. The multi-cell regulation device according to claim 2, wherein The number of the autotrophic denitrification tanks is 2-10.

4. The multi-cell regulation device according to claim 3, wherein The autotrophic denitrification tanks comprise an autotrophic denitrification tank one (4), an autotrophic denitrification tank two (5) and an autotrophic denitrification tank three (6).

5. The multi-cell regulation device according to claim 4, wherein The water inlet pipe comprises a water inlet pipe one (804), a water inlet pipe two (805) and a water inlet pipe three (806), the water inlet pipe one (804) is located between the autotrophic denitrification tank one (4) and the total water inlet pipe (807), the water inlet pipe two (805) is located between the autotrophic denitrification tank two (5) and the total water inlet pipe (807), and the water inlet pipe three (806) is located between the autotrophic denitrification tank three (6) and the total water inlet pipe (807). The water outlet pipe comprises a water outlet pipe one (301) between the autotrophic denitrification tank one (4) and the clear water tank (2), a water outlet pipe two (302) between the autotrophic denitrification tank two (5) and the clear water tank (2), and a water outlet pipe three (303) between the autotrophic denitrification tank three (6) and the clear water tank.

6. A method for denitrification of sewage, characterized by, The autotrophic denitrification multi-cell regulation device of any one of claims 1 to 5 is used for sewage denitrification. The method comprises the following steps: the sewage to be treated is introduced into the multi-cell regulation device for sewage treatment.

7. The method of claim 6, wherein, The number of autotrophic denitrification tanks opened in the multi-cell regulation device and the residence time of the sewage in the autotrophic denitrification tanks are adjusted according to the content of nitrate in the sewage and the temperature of the sewage to be treated.

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