A sewage treatment system and method

Abstract

The application discloses a sewage treatment system and method, which comprises a coagulation tank, a flocculation tank and a sedimentation tank. The coagulation tank, the flocculation tank and the sedimentation tank are sequentially communicated along the sewage flow direction. In addition, part of the sediment in the sedimentation tank returns to the flocculation tank. The system further comprises a control module, which comprises a carrier control module, the carrier control module adjusts the amount of circulating carriers and the amount of external carriers in the sediment returned by the sedimentation tank to the flocculation tank by monitoring the first actual carrier density in the coagulation tank and the water quantity and water quality of the water inlet end, so that the carrier density in the flocculation tank is kept within a first preset range; and a dosing control module, the dosing control module adjusts the dosing amount added to the coagulation tank and the flocculation tank by monitoring the second actual carrier density of the flocculation tank and combining the water quantity and water quality of the water inlet end. The sewage treatment system and method of the embodiment of the application improve the efficiency of sewage treatment and the water quality by coordinating the sewage treatment equipment.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment technology, and in particular to a wastewater treatment system and method. Background Technology

[0002] Currently, wastewater treatment systems suffer from problems such as mixed connections and misaligned drainage networks, easily leading to overflow pollution from combined sewer overflows and subsequent water pollution. Among numerous solutions, decentralized wastewater treatment is a crucial approach. Combined sewer overflow (CSO) treatment plants and equipment are typically used to manage water pollution caused by overflows. Overflow pollution is characterized by large fluctuations in water quality and quantity, poor stability, and strong randomness. When treating overflow pollution or co-treating rainwater and wastewater from wastewater treatment plants, the system faces the challenge of massive instantaneous overflow volumes and random locations. Therefore, wastewater treatment systems need to achieve high treatment loads and efficiencies within a limited land area. Even in the advanced treatment phase of wastewater treatment plants, high-efficiency sedimentation tanks in the system face throughput challenges. Currently, overflow treatment still suffers from low efficiency and low load, making improving equipment operating efficiency to cope with drastic changes in influent water quality and enhancing overflow pollution control effectiveness a critical need in wastewater treatment.

[0003] Patent CN113321283 discloses an artificial intelligence-based chemical dosing coagulation and sedimentation system, comprising a wastewater tank, a chemical dosing tank, a liquid mixing and diversion tank, a coagulation and sedimentation tank, and a purified water testing tank. These tanks are adjacent and interconnected, arranged sequentially along a horizontal path. The system also includes a wastewater influent source acquisition system, a wastewater source data acquisition and processing system, a PLC control system, and an operation monitoring system. Through the intelligent dosing system and the intelligent chemical dosing coagulation and sedimentation system, multiple motors and circulating pumps can be controlled to perform corresponding operations. During operation, the system automatically controls the metering and dosing of chemicals, monitors the status of the chemicals, and selects accurate real-time dosage data under different environmental conditions.

[0004] Patent CN113264645 discloses a domestic sewage treatment system, including a cyclone grit chamber, a biological system, an advanced treatment system, a disinfection system, and a sludge disposal system. The biological system includes an anaerobic tank, an anoxic tank, an aerobic tank, and a first sedimentation tank arranged sequentially according to the sewage flow direction. The advanced treatment system includes a multi-effect clarifier, which includes a coagulation tank, a flocculation tank, and a second sedimentation tank arranged sequentially according to the sewage flow direction. Both the anoxic and aerobic tanks contain several suspended media, and the anoxic tank is equipped with two submersible mixers. The bottom of the aerobic tank is equipped with multiple staggered water distributors and multiple aeration devices.

[0005] The aforementioned system discloses the basic components of the wastewater treatment system and the adjustment of chemical dosage based on the influent water quality. However, it does not disclose how to coordinate the operation of each component in the wastewater treatment system to ensure its efficient and stable operation. It is unable to effectively cope with drastic changes in overflow water quality and still suffers from low equipment operating efficiency and poor overflow pollution control.

[0006] In view of the above technical problems, this invention is hereby introduced. Summary of the Invention

[0007] The first objective of this invention is to propose a wastewater treatment system that is applicable to scenarios such as overflow wastewater treatment during the rainy season, rainwater and sewage system treatment at wastewater treatment plants, and advanced wastewater treatment. Through the high-load and highly intelligent coordinated operation of the wastewater treatment system, efficient and stable wastewater treatment can be achieved.

[0008] The second objective of this invention is to provide a wastewater treatment method.

[0009] To achieve the above objectives, the first aspect of the present invention provides a wastewater treatment system, comprising a coagulation tank, a flocculation tank, and a sedimentation tank, wherein the coagulation tank, flocculation tank, and sedimentation tank are sequentially connected along the wastewater flow direction, and a portion of the sediment in the sedimentation tank is returned to the flocculation tank. The system also includes a control module, which comprises:

[0010] The carrier control module monitors the actual carrier density in the coagulation tank, as well as the water volume and quality at the inlet, and adjusts the amount of circulating carrier and external loading in the sediment returned to the flocculation tank from the sedimentation tank to maintain the carrier density in the flocculation tank within a first preset range.

[0011] The dosing control module monitors the density of the second actual carrier in the flocculation tank and adjusts the amount of chemicals added to the coagulation and flocculation tanks based on the water volume and quality at the inlet.

[0012] Furthermore, the carrier control module includes a sedimentation tank material control module, which determines whether to return the sediment from the sedimentation tank to the flocculation tank based on the sludge level in the sedimentation tank.

[0013] Furthermore, the system also includes a sludge treatment device connected to a sedimentation tank. The sedimentation tank material control module controls the amount of sediment transported from the sedimentation tank to the sludge treatment device to maintain the sludge level in the sedimentation tank within a second preset range.

[0014] Furthermore, the system also includes a carrier separation device connected to a sedimentation tank. The sediment in the sedimentation tank is separated by the carrier separation device, and the circulating carrier enters the flocculation tank. The remaining sediment after separating the circulating carrier is transported to the sludge treatment device.

[0015] Furthermore, the system also includes an effluent water quality monitoring module, which monitors the water quality at the effluent end of the sedimentation tank and feeds it back to the dosing control module to further adjust the dosage of chemicals added to the coagulation tank and flocculation tank.

[0016] Furthermore, the sludge treatment unit is connected to the flocculation tank, and at least part of the supernatant in the sludge treatment unit is returned to the flocculation tank.

[0017] Furthermore, a gap is provided between the coagulation tank and the flocculation tank, and the sewage flows from the coagulation tank to the flocculation tank through the gap along the anti-gravity direction.

[0018] Furthermore, multiple slippery surfaces are formed on the inner wall of the sedimentation tank along the axial direction of the sedimentation tank, and a slope difference is formed between the multiple slippery surfaces.

[0019] Furthermore, the distance between the outlet of the flocculation tank and the bottom of the sedimentation tank is less than half the height of the sedimentation tank wall.

[0020] By applying the technical solutions in the above embodiments of the present invention, the following technical effects are achieved:

[0021] 1. This wastewater treatment system controls the operation of equipment in the system by monitoring its operational data, achieving coordinated operation of the equipment and enabling intelligent control to flexibly and quickly respond to drastic changes in influent water quality, thus effectively improving the efficiency and effluent quality of the wastewater treatment system.

[0022] 2. This wastewater treatment method increases the weight of flocs produced by flocculation by controlling the carrier density, thereby increasing the sedimentation rate, shortening the flocculation reaction time, and improving the removal efficiency of pollutants.

[0023] 3. This wastewater treatment system improves the utilization rate of the carrier by recycling the carrier in the sediment to the flocculation tank, thereby reducing the amount of carrier to be added.

[0024] 4. This wastewater treatment system can reduce the amount of chemicals needed while ensuring high-efficiency operation of wastewater treatment by adjusting the dosage according to the carrier density.

[0025] To achieve the above objectives, a second aspect of the present invention provides a wastewater treatment method, comprising:

[0026] Step S1: Monitor the first actual carrier density in the coagulation tank and the water volume and quality at the inlet, and adjust the amount of circulating carrier and external loading in the sediment returned from the sedimentation tank to the flocculation tank so that the carrier density in the flocculation tank is kept within the first preset range.

[0027] Step S2: Monitor the second actual carrier density in the flocculation tank, and adjust the dosage of chemicals added to the coagulation tank and flocculation tank based on the water volume and quality at the inlet.

[0028] Furthermore, the carrier control module outputs a first preset sub-range based on the water quality at the inlet end. Step S1 includes:

[0029] Step S11: Determine whether the density of the first actual carrier is greater than the first preset sub-range;

[0030] Step S12: When the first actual carrier density is less than or equal to the first preset sub-range, the carrier loss in the flocculation tank is calculated based on the first actual carrier density and the first preset sub-range.

[0031] Step S13: Obtain the actual sludge level in the sedimentation tank and determine whether the actual sludge level is greater than or equal to the preset sludge level;

[0032] Step S14: When the actual mud level is greater than or equal to the preset mud level, the sediment is returned from the sedimentation tank 3 and the circulating carrier is separated into the flocculation tank according to the amount of carrier missing.

[0033] Step S15: Determine the external loading volume based on the cyclic carrier volume and the carrier missing volume.

[0034] Furthermore, step S1 also includes:

[0035] Step S16: When the density of the first actual carrier is greater than the first preset sub-range, the sediment is transported from the sedimentation tank to the sludge disposal device to keep the sludge level in the sedimentation tank within the second preset range.

[0036] Furthermore, step S1 also includes:

[0037] Step S17: The remaining precipitate after separating the circulating carrier is transported to the sludge treatment device.

[0038] Furthermore, the method also includes:

[0039] Step S3: At least a portion of the supernatant in the sludge treatment device is returned to the flocculation tank.

[0040] Furthermore, the method also includes:

[0041] Step S4: Monitor the water quality at the effluent end of the sedimentation tank and further adjust the dosage of chemicals added to the coagulation and flocculation tanks.

[0042] By applying the technical solutions in the above embodiments of the present invention, the following technical effects are achieved:

[0043] 1. This wastewater treatment method controls the operation of equipment in the wastewater treatment system by monitoring the system's operational data, achieving coordinated operation of the equipment and enabling intelligent control to flexibly and quickly respond to drastic changes in influent water quality, effectively improving the efficiency and effluent quality of the wastewater treatment system.

[0044] 2. This wastewater treatment method increases the weight of flocs produced by flocculation by controlling the carrier density, thereby increasing the sedimentation rate, shortening the flocculation reaction time, and improving the removal efficiency of pollutants.

[0045] 3. This wastewater treatment method improves the utilization rate of the carrier by recycling the carrier in the sediment to the flocculation tank, thereby reducing the amount of carrier to be added.

[0046] 4. This wastewater treatment method can reduce the amount of chemicals added while ensuring high efficiency in wastewater treatment by adjusting the dosage according to the carrier density.

[0047] Additional aspects and advantages of the invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0048] The accompanying drawings, which form part of this specification, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0049] Figure 1 A schematic diagram of the structure of a wastewater treatment system according to one embodiment is shown;

[0050] Figure 2 A schematic diagram of the structure of another embodiment of a wastewater treatment system is shown;

[0051] Figure 3 A structural schematic diagram of a wastewater treatment system according to yet another embodiment is presented;

[0052] Figure 4 A structural schematic diagram of a wastewater treatment system according to another embodiment is shown;

[0053] Figure 5 A schematic diagram of the connection between the coagulation tank and the flocculation tank in a specific embodiment is shown;

[0054] Figure 6 A structural schematic diagram of a sedimentation tank in a specific embodiment is shown;

[0055] Figure 7 A schematic diagram of the connection between the flocculation tank and the sedimentation tank in a specific embodiment is shown;

[0056] Figure 8 A flowchart of a wastewater treatment method according to one embodiment is provided;

[0057] Figure 9 A flowchart of step S1 in one embodiment is presented;

[0058] Figure 10 A flowchart of step S1 in another embodiment is presented;

[0059] Figure 11 A flowchart of step S1 in yet another embodiment is presented;

[0060] Figure 12 A flowchart of another embodiment of a wastewater treatment method is presented;

[0061] Figure 13 A flowchart of another embodiment of a wastewater treatment method is presented;

[0062] Figure 14 A schematic diagram of a wastewater treatment system according to a specific embodiment is shown;

[0063] Figure 15 A control logic diagram of an intelligent control system in a specific embodiment is presented.

[0064] Attached reference numerals: 1. Coagulation tank; 2. Flocculation tank; 3. Sedimentation tank; 31. First sludge slip surface; 32. Second sludge slip surface; 4. Control module; 41. Carrier control module; 42. Dosing control module; 5. Sludge treatment device; 6. Carrier separation device; 7. Effluent water quality monitoring module; 110. Reaction tank; 111. Coagulation tank; 112. First flocculation tank; 113. Second flocculation tank; 114. Sedimentation tank; 1141. Sludge pump; 1142. Circulation valve; 1143. Sludge discharge valve; 115. Mixer; 120. Monitoring equipment; 121. Influent monitoring instrument; 122. Effluent water quality monitoring instrument. Instruments; 123. Density meter; 1231. First density meter; 1232. Second density meter; 124. Liquid level gauge; 125. Sludge level gauge; 1251. First sludge level gauge; 1252. Second sludge level gauge; 126. Pressure gauge; 130. Dosing device; 131. Dosing pump; 132. Chemical room; 133. Dosing point; 140. Carrier addition and circulation device; 141. Electrically controlled valve; 142. Hydrocyclone; 143. Carrier adder; 150. Sludge treatment device; 151. Supernatant pump; 152. Sludge tank sludge pump; 160. Intelligent control system; 170. Frequency converter; 180. Valve. Detailed Implementation

[0065] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0066] The present invention will be further described in detail below with reference to specific embodiments, which should not be construed as limiting the scope of protection claimed by the present invention.

[0067] In this description, 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 direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances. Furthermore, in the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0068] The wastewater treatment system and method of this application are described below with reference to the accompanying drawings.

[0069] Figure 1 This is a schematic diagram of the structure of a sewage treatment system according to an embodiment of this application.

[0070] This embodiment addresses scenarios such as overflow sewage treatment during the rainy season, stormwater and sewage system treatment at sewage treatment plants, and advanced sewage treatment. Through the high-load and highly intelligent coordinated operation of the sewage treatment system, it achieves efficient and stable sewage treatment, solving the problem of low operating load in conventional sewage treatment systems.

[0071] In this embodiment, as Figure 1 As shown, the wastewater treatment system includes a coagulation tank 1, a flocculation tank 2, and a sedimentation tank 3, which are sequentially connected along the wastewater flow direction. Wastewater flows through the tank structures sequentially, reacting with chemicals and carriers in the process. The flocs produced by the flocculation reaction are then carried into the sedimentation tank for settling, thereby purifying the wastewater.

[0072] In this embodiment, part of the sediment in sedimentation tank 3 is returned to flocculation tank 2 to achieve the recycling of the carrier in the sediment.

[0073] In this embodiment, as Figure 1 As shown, in order to cope with drastic changes in the quality of incoming water, the sewage treatment system also includes a control module 4, which is used to monitor the operating data of the sewage treatment system and control the operation of the equipment in the sewage treatment system. By coordinating the equipment in the sewage treatment system, intelligent control of the sewage treatment process is realized, and the operating efficiency of each piece of equipment in the sewage treatment system is effectively improved, thereby improving the efficiency of sewage treatment and the quality of effluent.

[0074] Specifically, such as Figure 1 As shown, the control module 4 includes a carrier control module 41 and a dosing control module 42. The carrier control module 41 monitors the first actual carrier density in the coagulation tank 1, as well as the water volume and quality at the inlet, and adjusts the amount of circulating carrier and external loading in the sediment returned from the sedimentation tank 3 to the flocculation tank 2, so that the carrier density in the flocculation tank 2 is maintained within a first preset range.

[0075] Controlling the carrier density in flocculation tank 2 effectively increases the probability of collision between fine flocs, enabling them to quickly combine and form larger flocs. This increases the weight of the flocs produced by flocculation, improves the sedimentation rate, shortens the flocculation reaction time, and enhances the removal efficiency of pollutants. For example, the addition of heavy media increases the weight of the flocs produced by flocculation, increasing their gravity, accelerating sedimentation, shortening the reaction time, and improving the removal efficiency of total phosphorus (TP), suspended solids (SS), and chemical oxygen demand (COD). Furthermore, recycling the carrier from the precipitate back into the flocculation tank improves the carrier utilization rate.

[0076] The first preset range is determined based on past wastewater operation data and on-site operation and commissioning of the wastewater treatment system application scenario. It should be noted that on-site operation and commissioning can be conducted before the wastewater treatment system is put into operation, and the first preset range in carrier control module 1 is obtained by comprehensively considering past wastewater operation data. Furthermore, during the operation of the wastewater treatment system, on-site operation and commissioning can be carried out according to the treatment status and operational requirements of the wastewater treatment system, and the first preset range in carrier control module 1 is updated by comprehensively considering past wastewater operation data.

[0077] For example, as shown in Table 1, before or during the operation of the wastewater system, chemicals are added to coagulation tank 1 and flocculation tank 2 according to the water quality range (e.g., A1: C1~C2, where A represents the water quality range and C represents the water quality within the corresponding range). Then, based on the monitored value of the first actual carrier density in the wastewater, a carrier is added to flocculation tank 2 to control the gradual increase of the second actual carrier density, and the amount of added chemicals is reduced accordingly, so that the effluent quality meets the specifications and achieves optimal flocculation. In wastewater treatment, the carrier and chemicals need to work together. Through the above on-site operation and commissioning, the minimum amount of chemicals (M1) can be determined for this water quality range, and the corresponding maximum carrier density (B1) can be obtained.

[0078] In addition, before or during the operation of the wastewater system, chemicals are added to coagulation tank 1 and flocculation tank 2 according to the water quality range (e.g., A1: C1~C2, where A represents the water quality range and C represents the water quality within the corresponding range), without reducing the dosage. Then, a loading medium is added to flocculation tank 2, and flocculation is monitored. Based on the monitored value of the first actual carrier density in the wastewater, a loading medium is added to flocculation tank 2 to increase the weight of flocs during flocculation until optimal flocculation is achieved, and the minimum carrier density (B) under this water quality range is determined. b1 ), to make B b1 -B1 serves as the first preset sub-range corresponding to the water quality range at the inlet, ultimately yielding the first preset range B. b1 -B n .

[0079] Table 1 Correspondence of Influent Turbidity

[0080]

[0081]

[0082] It should be noted that during the actual operation of the wastewater treatment system, if the density of the carriers in the wastewater is high, the first actual carrier density in the coagulation tank will exceed the first preset range, which will in turn cause the second actual carrier density in the flocculation tank to exceed the first preset range.

[0083] In this embodiment, the dosing control module 42 monitors the second actual carrier density of the flocculation tank 2 and adjusts the dosage of chemicals added to the coagulation tank 1 and the flocculation tank 2 based on the water volume and quality at the inlet. The carrier control module 41 controls the carrier density in the flocculation tank 2 within a certain range by controlling the circulating carrier volume and the external loading volume. Therefore, it can adjust the dosage of chemicals in the reaction tank in conjunction with the second carrier density of the flocculation tank 2, thereby reducing the dosage of chemicals while ensuring high-efficiency operation of wastewater treatment.

[0084] In another embodiment, the carrier control module 41 includes a sedimentation tank material control module. Specifically, the sedimentation tank material control module determines whether to return the sediment from the sedimentation tank 3 to the flocculation tank 2 based on the sludge level of the sedimentation tank 3. This avoids situations where the amount of circulating carrier in the returned sediment is insufficient, and the problem of low carrier circulation efficiency caused by the return of sediment due to insufficient circulating carrier. The sludge level at which the sediment from the sedimentation tank 3 begins to return to the flocculation tank 2 can be determined based on the minimum value of a first preset range to meet the minimum carrier density requirement in the flocculation tank 2.

[0085] Furthermore, such as Figure 2As shown, the system also includes a sludge treatment device 5, which is connected to the sedimentation tank 3. The material control module controls the amount of sediment transported from the sedimentation tank 3 to the sludge treatment device 5 to maintain the sludge level in the sedimentation tank 3 within a second preset range. This second preset range is determined based on the sludge hopper height of the sedimentation tank 3, the maximum value of the first preset range, and the power of the on-site equipment, to meet the highest carrier density requirements in the flocculation tank 2 while simultaneously preventing the sludge level from exceeding the sludge hopper height and affecting the effluent.

[0086] In yet another embodiment, such as Figure 3 As shown, the system also includes a carrier separation device 6, which is connected to the sedimentation tank 3. Specifically, the precipitate in the sedimentation tank 3 is separated into circulating carriers by the carrier separation device 6, which then enter the flocculation tank 2. The remaining precipitate after separating the circulating carriers is transported to the sludge treatment device 5.

[0087] Furthermore, the sludge treatment device 5 is connected to the flocculation tank 2, and at least part of the supernatant in the sludge treatment device 5 is returned to the flocculation tank 2, which reduces the water loss caused by the return of sediment from the sedimentation tank 3, and improves the sludge concentration effect in the sludge treatment device 5 after the supernatant is returned.

[0088] In yet another embodiment, such as Figure 4 As shown, the system also includes an effluent water quality monitoring module 7. Specifically, the effluent water quality monitoring module 7 monitors the water quality at the effluent end of the sedimentation tank 3 and feeds it back to the dosing control module 42 to further adjust the dosage of chemicals added to the coagulation tank 1 and the flocculation tank 2, so as to ensure the wastewater treatment quality of the wastewater treatment system by adjusting the dosage in a timely and accurate manner.

[0089] In one specific embodiment, such as Figure 5 As shown, a gap can be provided between the coagulation tank 1 and the flocculation tank 2, allowing sewage to flow from the coagulation tank 1 to the flocculation tank 2 along the anti-gravity direction. Through the high-level connection between the coagulation tank and the flocculation tank, sewage can flow through the flocculation tank 2 from top to bottom, allowing the chemicals and carriers to further contact and react fully with the sewage, thus improving the sewage treatment efficiency and quality.

[0090] Furthermore, multiple sludge surfaces are formed on the inner wall of sedimentation tank 3 along its axial direction, and these surfaces are separated by a gradient difference. For example, such as... Figure 6 As shown, the sedimentation tank 3 is provided with two sliding mud surfaces. The slope of the first sliding mud surface 31, which is located above the sedimentation tank 3 in the vertical direction, is small, which ensures the effective usable space of the sedimentation tank. The slope of the second sliding mud surface 32, which is located at the bottom of the sedimentation tank 3 in the vertical direction, is large, which can accelerate the sedimentation process of particulate matter in the sedimentation tank 3.

[0091] Furthermore, the distance between the outlet of flocculation tank 2 and the bottom of sedimentation tank 3 is less than half the height of the sedimentation tank 3 wall. For example, Figure 7 As shown, the flocculation tank 2 and the sedimentation tank 3 are connected at a low level to effectively prevent the flocs from breaking during startup due to residual flocs in the sedimentation tank 3 when the sewage treatment system is running intermittently during rainy days, thus ensuring the effluent quality of the sewage treatment system. In a preferred embodiment, the outlet height of the flocculation tank 2 is higher than the upper edge of the sludge hopper in the sedimentation tank 3.

[0092] By applying the technical solutions in the above embodiments of the present invention, the following technical effects are achieved:

[0093] 1. This wastewater treatment system controls the operation of equipment in the system by monitoring its operational data, achieving coordinated operation of the equipment and enabling intelligent control to flexibly and quickly respond to drastic changes in influent water quality, thus effectively improving the efficiency and effluent quality of the wastewater treatment system.

[0094] 2. This wastewater treatment method increases the weight of flocs produced by flocculation by controlling the carrier density, thereby increasing the sedimentation rate, shortening the flocculation reaction time, and improving the removal efficiency of pollutants.

[0095] 3. This wastewater treatment system improves the utilization rate of the carrier by recycling the carrier in the sediment to the flocculation tank, thereby reducing the amount of carrier to be added.

[0096] 4. This wastewater treatment system can reduce the amount of chemicals needed while ensuring high-efficiency operation of wastewater treatment by adjusting the dosage according to the carrier density.

[0097] In order to put the above embodiments into application, the present invention also proposes a wastewater treatment method.

[0098] Figure 8 This is a flowchart of a wastewater treatment method according to an embodiment of the present invention, which specifically includes the following steps:

[0099] Step S1: Monitor the first actual carrier density in coagulation tank 1 as well as the water volume and water quality at the inlet, and adjust the amount of circulating carrier and external loading in the sediment returned from sedimentation tank 3 to flocculation tank 2 so that the carrier density in flocculation tank 2 is maintained within the first preset range.

[0100] Specifically, such as Figure 9 As shown, step S1 includes the following steps:

[0101] Step S11: Determine whether the density of the first actual carrier is greater than the first preset sub-range corresponding to the water quality.

[0102] Among them, the carrier control module outputs a first preset sub-range based on the water quality at the inlet end.

[0103] Step S12: When the first actual carrier density is less than or equal to the first preset sub-range, the carrier loss in the flocculation tank 2 is calculated based on the first actual carrier density and the first preset range.

[0104] In a preferred embodiment, the carrier deletion amount can be calculated using the following formula: M s =M max -ρ a V a , of which M s M represents the amount of vector missing. max ρ represents the maximum value of the first preset subrange. a V represents the first actual carrier density. a This indicates the volume of the coagulation tank. The above process calculates the carrier loss based on the maximum value of the first preset range, which can maintain the carrier density in the flocculation tank at a high level, thereby enabling the subsequent dosage in the coagulation and flocculation tanks to be controlled at a low level.

[0105] Step S13: Obtain the actual sludge level in sedimentation tank 3 and determine whether the actual sludge level is greater than or equal to the preset sludge level.

[0106] Step S14: When the actual mud level is greater than or equal to the preset mud level, the sediment is returned from the sedimentation tank 3 and the circulating carrier is separated and transferred to the flocculation tank 2 according to the amount of carrier missing.

[0107] Step S15: Determine the external loading volume based on the cyclic carrier volume and the carrier missing volume.

[0108] In one specific embodiment, the external load volume can be calculated using the following formula: M d = Mmax - ρbVb, where Md represents the external loading volume, Mmax represents the maximum value of the first preset sub-range, and ρ b V represents the second actual carrier density in the flocculation tank after the circulating carrier is added. b This indicates the volume of the flocculation tank.

[0109] S2, monitor the second actual carrier density of flocculation tank 2, and adjust the dosage of chemicals added to coagulation tank 1 and flocculation tank 2 based on the water volume and water quality at the inlet.

[0110] In one embodiment of the present invention, the initial dosage can be matched according to the water volume and quality at the inlet, and then the initial dosage can be adjusted according to the second actual carrier density to determine the final dosage. The carrier can increase the probability of collision of fine flocs, thereby enabling them to quickly combine and form larger flocs, increasing the weight of the flocs produced by flocculation, improving the sedimentation rate, shortening the flocculation reaction time, and improving the removal efficiency of pollutants. By having a certain carrier density in the flocculation tank 2, the dosage can be reduced accordingly, thereby effectively saving the dosage while ensuring that the drug and water can react fully, and improving the treatment efficiency and quality of wastewater through the efficient combination of carrier and drug.

[0111] In another embodiment, such as Figure 10 As shown, step S1 further includes:

[0112] Step S16: When the density of the first actual carrier is greater than the first preset sub-range, the sediment is transported from the sedimentation tank 3 to the sludge treatment device 5 to keep the sludge level in the sedimentation tank 3 within the second preset range.

[0113] In one embodiment of the present invention, when the first actual carrier density is greater than the first preset sub-range, it indicates that the carrier density in the flocculation tank has reached a high level. By conveying precipitate from the sedimentation tank 3 to the sludge disposal device 5, sludge accumulation in the sedimentation tank can be avoided. Simultaneously, to ensure that precipitate can be promptly returned from the sedimentation tank 3 and the circulating carrier separated and returned to the flocculation tank 2 when the carrier density in the flocculation tank 2 is insufficient, the amount of precipitate from the sedimentation tank 3 to the sludge disposal device 5 can be controlled to maintain the sludge level in the sedimentation tank 3 within the second preset range.

[0114] In yet another embodiment, such as Figure 11 As shown, step S1 further includes:

[0115] Step S17: The remaining precipitate after separating the circulating carrier is transported to the sludge treatment device 5. This allows for the centralized treatment and utilization of the sludge in the remaining precipitate.

[0116] In yet another embodiment, such as Figure 12 As shown, the method also includes:

[0117] Step S3 involves returning at least a portion of the supernatant from the sludge treatment device 5 to the flocculation tank 2. Returning the supernatant to the flocculation tank 2 reduces water loss in the treatment system and achieves sludge concentration in the sludge treatment device 5.

[0118] It should be noted that the amount of supernatant returned to flocculation tank 2 is affected by the liquid level in the sludge treatment device 5. This liquid level is affected by the amount of sediment transported to the sludge treatment device 5, including the remaining sediment transported to the sludge treatment device 5 after separation of the circulating carrier, and the sediment transported to the sludge treatment device 5 from sedimentation tank 3. When the supernatant level in the sludge treatment device 5 reaches the preset level value, the supernatant in the sludge treatment device 5 will be returned to flocculation tank 2.

[0119] In another embodiment, such as Figure 13 As shown, the method also includes:

[0120] Step S4: Monitor the water quality at the outlet of sedimentation tank 3 and further adjust the dosage of chemicals added to coagulation tank 1 and flocculation tank 2.

[0121] By monitoring the water quality at the effluent outlet of sedimentation tank 3, it is possible to quickly and promptly determine whether the effluent quality meets the requirements of the wastewater treatment system in its current scenario. This allows for flexible and accurate adjustment of the dosage to ensure that the effluent quality of the wastewater treatment system meets the quality requirements under various scenarios.

[0122] 1. This wastewater treatment method controls the operation of equipment in the wastewater treatment system by monitoring the system's operational data, achieving coordinated operation of the equipment and enabling flexible and rapid response to drastic changes in incoming water quality through intelligent control, thus effectively improving the efficiency and effluent quality of the wastewater treatment system.

[0123] 2. This wastewater treatment method increases the weight of flocs produced by flocculation by controlling the carrier density, thereby increasing the sedimentation rate, shortening the flocculation reaction time, and improving the removal efficiency of pollutants.

[0124] 3. This wastewater treatment method improves the utilization rate of the carrier by recycling the carrier in the sediment to the flocculation tank, thereby reducing the amount of carrier to be added.

[0125] 4. This wastewater treatment method can reduce the amount of chemicals added while ensuring high efficiency in wastewater treatment by adjusting the dosage according to the carrier density.

[0126] The wastewater treatment system and method are described in detail below with reference to a specific embodiment.

[0127] like Figure 14 As shown in this specific embodiment, the wastewater treatment system includes a reaction tank 110, monitoring equipment 120, a dosing device 130, a carrier addition and circulation device 140, a sludge disposal device 150, and an intelligent control system 160. The components of the sludge treatment system are interconnected and achieve intelligent collaborative control through the intelligent control system 160 to achieve high-load wastewater treatment results.

[0128] It is worth noting that this wastewater treatment system occupies a small area and can be flexibly arranged, enabling it to efficiently and stably treat overflow water with a large instantaneous flow rate within a limited space.

[0129] Specifically, such as Figure 14 and Figure 15 As shown, the reaction tank 110 includes a coagulation tank 111, a first flocculation tank 112, a second flocculation tank 113, and a sedimentation tank 114. Furthermore, a mixer 115 controlled by a frequency converter 170 is installed in the coagulation tank 111, the first flocculation tank 112, and the second flocculation tank 113. This mixer can create a hydraulic direction consistent with the direction of wastewater flow, meaning the hydraulic directions created by the mixer in the coagulation tank 111, the first flocculation tank 112, and the second flocculation tank 113 are downward, downward, and upward, respectively.

[0130] In addition, a sludge pump 1141, a circulation valve 1142, and a sludge discharge valve 1143 are installed in the sedimentation tank 114. The sludge pump 1141 is used to pump out the sediment in the sedimentation tank 114, and when the circulation valve 1142 is open, the sediment is pumped into the carrier addition and circulation device 140. When the sludge discharge valve 1143 is open, the sediment is pumped into the sludge treatment device 150.

[0131] Monitoring equipment 120 is installed in the corresponding structure of the pool to monitor the real-time operating data of the wastewater treatment system and feed the data back to the intelligent control system 160. Specifically, such as... Figure 14 As shown, the monitoring equipment 120 includes an influent monitor 121, an effluent water quality monitor 122, a density meter 123, a level gauge 124, a sludge level gauge 125, and a pressure gauge 126.

[0132] The influent monitoring instrument 121 is installed at the influent pipe of the coagulation tank 111 to monitor the influent water quality and flow rate. In this embodiment, the influent water quality includes turbidity, suspended solids (SS), carbon dioxide (COD), ammonia nitrogen, and total phosphorus (TP). The effluent water quality monitoring instrument 122 is installed at the effluent pipe of the sedimentation tank 114 to monitor the water quality after treatment by the wastewater treatment system. In this embodiment, the effluent water quality includes turbidity, suspended solids (SS), carbon dioxide (COD), ammonia nitrogen, and total phosphorus (TP).

[0133] The density meter 123 includes a first density meter 1231 installed in the coagulation tank 111 and a second density meter 1232 installed in the first flocculation tank 112. The first density meter 1231 is used to monitor the actual carrier density in the coagulation tank 111, and the second density meter 1232 is used to monitor the actual carrier density in the first flocculation tank 112. The level gauge 124 is installed in the sludge treatment device 150 to monitor the liquid level in the sludge treatment device.

[0134] The sludge level gauge 125 includes a first sludge level gauge 1251 installed in the sedimentation tank 114 and a second sludge level gauge 1252 installed in the sludge treatment device 150. The first sludge level gauge 1251 monitors the sludge level in the sedimentation tank 114, and the second sludge level gauge 1252 monitors the sludge level in the sludge treatment device 150. The pressure gauge 126 is installed in the carrier addition and circulation device and is used to monitor the pressure generated by the sludge pump 1141.

[0135] The dosing device 130 includes a dosing pump 131 controlled by a frequency converter 170 and a valve 180, and a drug chamber 132 and multiple dosing points 133 connected to the dosing pump 131. The first dosing point is a dosing mixer located on the inlet pipe, used to add PAC (polyaluminum chloride) to the inlet pipe according to control information from the intelligent control system 160. The second dosing point is a dosing tray covering the inlet pipe opening at the junction of the inlet pipe and the coagulation tank 111, used to add PAC to the coagulation tank 111 according to control information from the intelligent control system 160. The third dosing point is a dosing tray located at the junction of the coagulation tank 111 and the first flocculation tank 112, used to add PAM (polyacrylamide) or nano-flocculators to the first flocculation tank 112 according to control information from the intelligent control system 160. Furthermore, the drug mixing degree at the dosing points can be increased through structural design or the dosing mixing components.

[0136] The carrier addition and circulation device 140 includes a hydrocyclone 142 and a carrier adder 143, both connected to an electrically controlled valve 141. Specifically, the hydrocyclone is used to separate the carrier from the sediment pumped into the sedimentation tank 114 into the first flocculation tank 112 according to control information from the intelligent control system 160, and to separate the remaining sediment into the sludge disposal device 150. The carrier adder is used to add an external loading medium into the first flocculation tank 112. In this embodiment, the carrier is a mineral or placer. Preferably, the diameter of the carrier is 60-150 μm, and the carrier density is 2-5 g / m³. 3 .

[0137] The sludge treatment device 150 includes a supernatant pump 151 and a sludge tank pump 152 controlled by a frequency converter 170 and a valve 180. Specifically, the supernatant pump is used to pump the supernatant in the sludge treatment device 150 into the first flocculation tank 112 according to the control information of the intelligent control system 160. The sludge tank pump is used to pump the sludge in the sludge treatment device 150 out of the sludge treatment device 150 to participate in the external sludge-water circulation.

[0138] like Figure 15 As shown, the intelligent control system 160 controls the operation of the sewage treatment system based on the monitoring data fed back by the monitoring equipment 120.

[0139] The intelligent control system 160 performs multi-faceted control over the wastewater treatment system, which will be described in detail below.

[0140] The intelligent control system 160 obtains the amount of chemicals added to the reaction tank and controls the frequency converter to adjust the agitator accordingly, so as to match the speed and dosage of chemicals and make the flocculation reaction more complete.

[0141] The intelligent control system 160 acquires the influent water quality monitored by the influent monitor 121 and the actual carrier density in the first flocculation tank 112 monitored by the density meter 123, and performs comprehensive analysis on both to control the frequency converter and valves to adjust the dosage, type, and time interval of the dosing pump. Specifically, as shown in Table 1, the corresponding dosage is first determined by different influent turbidity ranges, such as M1 corresponding to range A1. Then, the amount of M1 is adjusted according to the actual carrier density in the first flocculation tank 112 to determine the final dosage.

[0142] The intelligent control system 160 acquires the preset carrier density B0-B1 in the first flocculation tank 112 and the actual carrier density in the coagulation tank 111 monitored by the densitometer 123, in order to control the amount of sediment pumped into the carrier addition and circulation device 140 via the circulation valve 1142. Further, the intelligent control system 160 acquires the aforementioned sediment amount to control the frequency converter to adjust the frequency of the sludge pump 1141, and acquires the pressure value monitored by the pressure gauge 126 to adjust the specifications and number of hydrocyclones opened to improve the carrier separation efficiency. In addition, the intelligent control system 160 also acquires the actual carrier density in the first flocculation tank 112 monitored by the densitometer 123 after the addition of circulating carrier, in order to control the amount of external loading K added to the first flocculation tank 112 by the carrier adder.

[0143] The intelligent control system 160 acquires the sludge level in the sedimentation tank 114 monitored by the first sludge level gauge 1251, and controls the start of the sludge pump 1141 accordingly. Specifically, when the monitored sludge level in the sedimentation tank 114 is greater than or equal to a preset sludge level H, the sludge pump 1141 is started; when the monitored sludge level in the sedimentation tank 114 is less than the preset sludge level H, the sludge pump 1141 is stopped. It should be noted that the preset sludge level H is based on the minimum preset carrier density B. b1 Sure.

[0144] The intelligent control system 160 acquires the sludge level in the sludge treatment device 150 monitored by the second sludge level gauge 1252, and controls the frequency converter to adjust the frequency at which the sludge treatment device 150 pumps sludge into the sludge-water external circulation system. This enables the reuse of concentrated sludge and prevents sludge accumulation from hindering the operation of the wastewater treatment system. Furthermore, the intelligent control system 160 also acquires the liquid level in the sludge treatment device 150 monitored by the liquid level gauge 124, and controls the frequency converter to adjust the frequency at which the supernatant is pumped into the flocculation tank 2. This effectively avoids water loss due to sediment returning to the sedimentation tank and improves the sludge concentration effect in the sludge treatment device.

[0145] In one specific embodiment, the above-mentioned wastewater treatment system can be put into use using wastewater treatment methods.

[0146] After the wastewater treatment system has been running for a period of time, the influent monitor 121 detects that the influent turbidity increases from A1 to A2, the first density meter 1231 detects that the actual carrier density in the coagulation tank 111 increases but does not exceed the maximum value B2 of the first preset sub-range, and the first sludge level meter 1251 detects that the sludge level in the sedimentation tank 114 is higher than H.

[0147] The intelligent control system 160 adjusts the frequency of the sludge pump 1141 according to the actual carrier density monitored in the coagulation tank 111, so as to adjust the amount of sediment pumped from the sedimentation tank 114 into the carrier addition and circulation device through the circulation valve 1142, and puts the circulating carrier after the sediment is separated by the carrier addition and circulation device 140 into the first flocculation tank 112.

[0148] The first sludge level gauge 1251 continuously monitors the sludge level in the sedimentation tank 114. When the first sludge level gauge 1251 detects that the sludge level in the sedimentation tank 114 still exceeds the second preset range after the above-mentioned sediment is pumped out, the intelligent control system 160 controls the sludge pump 1141 to pump sediment from the sedimentation tank 114 to the sludge disposal device 150 through the sludge discharge valve 1143, and controls the amount of sediment pumped into the sludge disposal device 150 to keep the sludge level in the sedimentation tank 114 within the second preset range.

[0149] When the circulating carrier, after being separated from the carrier addition and circulation device 140, is added to the first flocculation tank 112, the second density meter 1232 detects that the actual carrier density in the first flocculation tank 112 has not yet reached the maximum value B2 of the first preset sub-range. The intelligent control system adds an external loading body to the first flocculation tank 112 according to the actual carrier density in the first flocculation tank 112 and the maximum value B2 of the first preset sub-range, so that the actual carrier density in the first flocculation tank 112 reaches the maximum value B2 of the first preset sub-range.

[0150] The intelligent control system 160 controls the dosing device 130 to add drugs at the dosing point based on the influent turbidity A2 and the actual carrier density in the first flocculation tank 112 monitored by the second density meter 1232 after the addition of the external loading body.

[0151] The above specific embodiments achieve intelligent and coordinated control of the sewage treatment system through an intelligent control system, realizing high-load sewage treatment effect. It can efficiently, stably, and quickly respond to large instantaneous flow of overflow water in a limited space, thereby improving the intelligence and stability of the sewage treatment system.

[0152] The above are merely several specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

[0153] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes the element.

[0154] It should be noted that, in the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

Claims

1. A wastewater treatment system comprising a coagulation tank (1), a flocculation tank (2), and a sedimentation tank (3), wherein the coagulation tank (1), the flocculation tank (2), and the sedimentation tank (3) are sequentially connected along the wastewater flow direction, and a portion of the sediment in the sedimentation tank (3) is returned to the flocculation tank (2), characterized in that, It also includes a control module (4), which includes: The carrier control module (41) monitors the first actual carrier density in the coagulation tank (1) and the water volume and quality at the inlet, and adjusts the amount of circulating carrier and external loading in the sediment returned from the sedimentation tank (3) to the flocculation tank (2), so that the carrier density in the flocculation tank (2) is maintained within a first preset range. The carrier control module (41) is configured to: determine the first preset sub-range of carrier density in the flocculation tank (2) corresponding to the current water quality based on the water quality at the inlet end; Determine whether the density of the first actual carrier is greater than the first preset sub-range; if the density of the first actual carrier is less than or equal to the first preset sub-range, calculate the carrier loss in the flocculation tank (2) based on the density of the first actual carrier and the first preset sub-range; obtain the actual sludge level of the sedimentation tank (3) and determine whether the actual sludge level is greater than or equal to the preset sludge level; when the actual sludge level is greater than or equal to the preset sludge level, return the sediment from the sedimentation tank (3) and separate the circulating carrier to the flocculation tank (2) based on the carrier loss; determine the external loading volume based on the circulating carrier volume and the carrier loss. The dosing control module (42) adjusts the amount of chemicals added to the coagulation tank (1) and the flocculation tank (2) by monitoring the second actual carrier density of the flocculation tank (2) and combining the water volume and water quality at the inlet.

2. The wastewater treatment system according to claim 1, characterized in that, The carrier control module (41) includes a sedimentation tank material control module, which determines whether to return the sediment in the sedimentation tank (3) to the flocculation tank (2) based on the sludge level in the sedimentation tank (3).

3. The wastewater treatment system according to claim 2, characterized in that, It also includes a sludge treatment device (5), which is connected to the sedimentation tank (3). The sedimentation tank material control module controls the amount of sediment transported from the sedimentation tank (3) to the sludge treatment device (5) to keep the sludge level in the sedimentation tank (3) within a second preset range.

4. The wastewater treatment system according to claim 3, characterized in that, It also includes a carrier separation device (6), which is connected to the sedimentation tank (3). The sediment in the sedimentation tank (3) is separated by the carrier separation device (6) and the circulating carrier enters the flocculation tank (2). The remaining sediment after separating the circulating carrier is transported to the sludge treatment device (5).

5. The wastewater treatment system according to claim 1, characterized in that, It also includes an effluent water quality monitoring module (7), which monitors the water quality at the effluent end of the sedimentation tank (3) and feeds it back to the dosing control module (42) to further adjust the amount of chemicals added to the coagulation tank (1) and the flocculation tank (2).

6. The wastewater treatment system according to claim 3, characterized in that, The sludge treatment device (5) is connected to the flocculation tank (2), and at least part of the supernatant in the sludge treatment device (5) is returned to the flocculation tank (2).

7. The wastewater treatment system according to claim 1, characterized in that, A gap is provided between the coagulation tank (1) and the flocculation tank (2), and the sewage flows from the coagulation tank (1) to the flocculation tank (2) along the anti-gravity direction.

8. The wastewater treatment system according to claim 1, characterized in that, The inner wall of the sedimentation tank (3) forms multiple slippery surfaces along the axial direction of the sedimentation tank (3), and a slope difference is formed between the multiple slippery surfaces.

9. The wastewater treatment system according to claim 1, characterized in that, The distance between the outlet of the flocculation tank (2) and the bottom of the sedimentation tank (3) is less than half the height of the wall of the sedimentation tank (3).

10. A wastewater treatment method, employing the wastewater treatment system according to any one of claims 1-9, characterized in that, include: Step S1: Monitor the first actual carrier density in the coagulation tank (1) as well as the water volume and water quality at the inlet, and adjust the amount of circulating carrier and external loading in the sediment returned from the sedimentation tank (3) to the flocculation tank (2) so that the carrier density in the flocculation tank (2) is kept within the first preset range. Step S1 includes: obtaining the water quality at the inlet end, and determining a first preset sub-range of carrier density in the flocculation tank (2) based on the water quality; It also includes step S11, determining whether the density of the first actual carrier is greater than the first preset sub-range; Step S12: If the first actual carrier density is less than or equal to the first preset sub-range, then calculate the carrier missing amount in the flocculation tank (2) based on the first actual carrier density and the first preset sub-range. Step S13: Obtain the actual sludge level of the sedimentation tank (3) and determine whether the actual sludge level is greater than or equal to the preset sludge level; Step S14: When the actual mud level value is greater than or equal to the preset mud level value, the sediment is returned from the sedimentation tank (3) and the circulating carrier is separated and transferred to the flocculation tank (2) according to the amount of carrier missing. Step S15: Determine the external loading volume based on the cyclic carrier quantity and the carrier missing quantity; Step S2: Monitor the second actual carrier density in the flocculation tank (2), and adjust the dosage of chemicals added to the coagulation tank (1) and flocculation tank (2) based on the water volume and water quality at the inlet.

11. The wastewater treatment method according to claim 10, characterized in that, Step S1 further includes: Step S16: When the density of the first actual carrier is greater than the first preset sub-range, the sediment is transported from the sedimentation tank (3) to the sludge disposal device (5) to keep the sludge level in the sedimentation tank (3) within the second preset range.

12. The wastewater treatment method according to claim 10, characterized in that, Step S1 further includes: Step S17: The remaining precipitate after separating the circulating carrier is transported to the sludge treatment device (5).

13. The wastewater treatment method according to claim 10, characterized in that, Also includes: Step S3, at least part of the supernatant in the sludge treatment device (5) is returned to the flocculation tank (2).

14. The wastewater treatment method according to claim 10, characterized in that, Also includes: Step S4: Monitor the water quality at the outlet of the sedimentation tank (3) and further adjust the dosage of chemicals added to the coagulation tank (1) and the flocculation tank (2).

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