A device for advanced treatment of phosphorus-containing pesticide wastewater

Abstract

The utility model discloses a kind of phosphorus-containing pesticide wastewater advanced treatment device, including sequentially connected coagulation sedimentation tank, electro-Fenton reaction tank, pH back pool, anaerobic UASB reaction tower and biochemical pool, first dosing port and first agitator are equipped on coagulation sedimentation tank, pH adjusting area and reaction zone are sequentially equipped in electro-Fenton reaction tank along water flow direction, acid dosing port and first pH meter are equipped on pH adjusting area, electrode unit is equipped in reaction zone, reaction zone is connected gas generating assembly, pH back pool is equipped with pH adjusting unit, second agitator and second dosing port, pH adjusting unit includes alkali dosing port and second pH meter, whole set of device degree of integration is high, processing procedure is smooth, impact load resistance is strong, finally effluent water quality is stable and up to standard, operating cost is significantly lower than traditional technology.

Description

Technical Field

[0001] This utility model relates to the field of water treatment technology, and in particular to a device for deep treatment of phosphorus-containing pesticide wastewater. Background Technology

[0002] Phosphorus-containing pesticide wastewater mainly originates from the production, synthesis, washing, and recycling of organophosphorus pesticides (such as dichlorvos, dimethoate, malathion, and chlorpyrifos). This type of wastewater is characterized by a wide variety of pollutants, complex composition, high concentration of organophosphorus compounds, high total phosphorus load, high COD / BOD ratio, poor biodegradability, high toxicity, and significant biological inhibition. It has long been a challenging issue in wastewater treatment.

[0003] Existing traditional processes (such as the simple Fenton process) generally suffer from problems such as large amounts of iron sludge generated, low ozone utilization (usually less than 30%), susceptibility of biological treatment processes to toxicity inhibition, high energy consumption, and difficulty in consistently achieving the required treatment results. Utility Model Content

[0004] In view of the shortcomings of the existing technology, the purpose of this utility model is to provide a deep treatment device for phosphorus-containing pesticide wastewater, which aims to solve the technical problems mentioned in the background art.

[0005] A deep treatment device for phosphorus-containing pesticide wastewater includes a coagulation sedimentation tank, an electro-Fenton reaction tank, a pH adjustment tank, an anaerobic UASB reaction tower, and a biological treatment tank connected in sequence. The coagulation sedimentation tank is equipped with a first dosing port for adding coagulant and a first agitator, with the stirring end of the first agitator extending into the coagulation sedimentation tank. The electro-Fenton reaction tank is equipped with a pH adjustment zone and a reaction zone arranged in sequence along the water flow direction. The pH adjustment zone is equipped with an acid dosing port and a first pH meter. The reaction zone is equipped with an electrode unit and is connected to a gas generating component, which supplies gas to the reaction zone through a gas pipeline. The pH adjustment tank is equipped with a pH adjustment unit, a second agitator, and a second dosing port for adding microbial agents. The pH adjustment unit includes an alkali dosing port and a second pH meter, with the stirring end of the second agitator extending into the pH adjustment tank.

[0006] The beneficial effects of this utility model are: Through multi-unit synergistic coupling, the problem of treating phosphorus-containing pesticide wastewater is effectively solved. The coagulation sedimentation tank effectively removes phosphates and suspended solids, reducing the load on subsequent units; the electro-Fenton-ozone micro-nano coupling system generates Fe in situ through electrodes. 2+The system combines ·OH with ozone generated through efficient mass transfer via micro-nano bubbles, synergistically producing a large number of free radicals. This significantly improves the chain breaking and degradation efficiency of recalcitrant organic pollutants, as well as ozone utilization, thereby significantly reducing wastewater toxicity and improving biodegradability. Simultaneously, it reduces the production of iron sludge associated with traditional electro-Fenton processes. A pH adjustment tank, through the addition of specific bacterial communities, rapidly stabilizes water quality, creating a suitable environment for the anaerobic system. Subsequent UASB combined with traditional biological carbon and phosphorus removal processes achieves efficient and stable biodegradation and deep purification of organic matter. The entire system is highly integrated, with a smooth treatment process, strong resistance to shock loads, and consistently meets effluent quality standards. Operating costs are significantly lower than traditional processes.

[0007] Furthermore, the electrode unit includes several electrode plate groups arranged at intervals, each electrode plate group including an anode plate and a cathode plate, the anode plate and the cathode plate being arranged in pairs, the anode plate being an iron plate and the cathode plate being a carbon felt.

[0008] Furthermore, the gas generating component includes a micro-nano bubble generator and an ozone generator. One end of the gas pipe is connected to the micro-nano bubble generator and the ozone generator, and the other end of the gas pipe extends into the reaction zone and is connected to a first aeration head located in the reaction zone.

[0009] Furthermore, the anaerobic UASB reactor is equipped with an anaerobic three-phase separator, and the top of the anaerobic UASB reactor is equipped with an outlet.

[0010] Furthermore, the biochemical tank includes an aerobic biological reaction zone, which is equipped with a membrane separation system and an aeration unit. The membrane separation system is used to intercept activated sludge and suspended pollutants, and the aeration unit includes a plurality of second aeration heads located at the bottom of the aerobic biological reaction zone.

[0011] Furthermore, the biochemical pool is also equipped with a level gauge.

[0012] Furthermore, a booster pump is installed on the connecting pipeline between the pH adjustment tank and the anaerobic UASB reactor.

[0013] Furthermore, the bottom of the coagulation sedimentation tank, the electro-Fenton reactor, the anaerobic UASB reactor, and the biochemical tank are all equipped with sludge discharge valves. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the advanced treatment device for phosphorus-containing pesticide wastewater according to the present invention.

[0015] In the diagram: 1. Coagulation sedimentation tank; 11. First dosing port; 12. First agitator; 2. Electro-Fenton reaction tank; 21. pH adjustment zone; 211. Acid dosing port; 212. First pH meter; 22. Reaction zone; 221. Electrode unit; 2211. Electrode plate assembly; 22111. Anode plate; 22112. Cathode plate; 222. First aeration head; 23. Gas generating assembly; 231. Micro / nano bubble generator; 232. Ozone generator. 3. pH Adjustment Tank; 31. pH Adjustment Unit; 311. Alkali Dosing Port; 312. Second pH Meter; 32. Second Agitator; 33. Second Dosing Port; 4. Anaerobic UASB Reactor; 41. Anaerobic Three-Phase Separator; 42. Air Outlet; 5. Biological Tank; 51. Aerobic Biological Reactor Zone; 511. Membrane Separation System; 512. Aeration Unit; 5121. Second Aeration Head; 52. Level Gauge; 6. Lifting Pump; 7. Sludge Discharge Valve.

[0016] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this utility model. Detailed Implementation

[0017] To facilitate understanding of this utility model, a more complete description will be given below with reference to the accompanying drawings. Several embodiments of this utility model are shown in the drawings. However, this utility model can be implemented in many different forms and is not limited to the embodiments described herein. Rather, these embodiments are provided so that the disclosure of this utility model will be more thorough and complete.

[0018] It should be noted that when a component is said to be "fixed to" another component, it can be directly on the other component or there may be an intervening component. When a component is said to be "connected to" another component, it can be directly connected to the other component or there may be an intervening component. The terms "vertical," "horizontal," "left," "right," and similar expressions used in this document are for illustrative purposes only.

[0019] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0020] See Figure 1 A deep treatment device for phosphorus-containing pesticide wastewater includes a coagulation sedimentation tank 1, an electro-Fenton reaction tank 2, a pH adjustment tank 3, an anaerobic UASB reaction tower 4, and a biochemical tank 5 connected in sequence.

[0021] Specifically, the coagulation sedimentation tank 1 is equipped with a first inlet 11 for adding coagulant and a first agitator 12. The stirring end of the first agitator 12 extends into the coagulation sedimentation tank 1, and FeCl3 is quantitatively added to the wastewater as a coagulant through the first inlet 11. The dosage is controlled to be approximately 0.3% of the total mass of the wastewater. 3+ It forms a stable FePO4 precipitate with phosphate, achieving a total phosphorus removal rate of over 95%. After addition, the first stirrer 12 is started for thorough mixing. In this embodiment, stirring is carried out at medium speed for about 15 minutes to promote uniform dispersion of FeCl3 in the water and induce hydrolysis, generating ferric hydroxide colloids with flocculation effect. Stirring is then stopped, allowing the wastewater to enter a settling stage for 60 minutes. During this process, the formed flocs gradually settle, effectively adsorbing and removing phosphates, most suspended solids, and some colloidal organic pollutants from the water. After sedimentation, the supernatant is used as preliminary purified effluent and introduced into the subsequent pH adjustment zone for further treatment.

[0022] Specifically, the electro-Fenton reaction tank 2 is provided with a pH adjustment zone 21 and a reaction zone 22 sequentially along the water flow direction. The pH adjustment zone 21 is equipped with an acid dosing port 211 and a first pH meter 212. The reaction zone 22 is connected to a gas generating assembly 23. The gas generating assembly 23 supplies gas to the reaction zone 22 through a gas pipe. The gas generating assembly 23 includes a micro-nano bubble generator 231 and an ozone generator 232. One end of the gas pipe is connected to the micro-nano bubble generator 231 and the ozone generator 232. 32 is connected, and the other end of the gas pipe extends into the reaction zone 22 and is connected to the first aeration head 222 located in the reaction zone 22. The reaction zone 22 is provided with an electrode unit 221, which includes a plurality of spaced electrode plate groups 2211. Each electrode plate group 2211 includes an anode plate 22111 and a cathode plate 22112. The anode plate 22111 and the cathode plate 22112 are arranged in pairs. The anode plate 22111 is an iron plate, and the cathode plate 22112 is a carbon felt.

[0023] It is worth mentioning that sulfuric acid is added through the acid dosing port 211 to adjust the pH value of the wastewater entering the pH adjustment zone 21 to 3±0.2, and the pH change is monitored in real time using the first pH meter 212. Subsequently, the wastewater enters the reaction zone 22. In this embodiment, the distance between the anode plate 22111 and the cathode plate 2212 is set to 60 cm, and a direct current with a current density of 30 mA / cm² and an operating voltage of 15 V is applied. The cathode plate 22112 reacts to generate hydroxyl radicals (…). OH), and Fe dissolved from anode plate 22111 2+ The Fenton reaction occurs, producing... OH radicals. Simultaneously, using a nanobubble generator and an ozone generator 232, ozone-containing micro- and nanobubbles are introduced into the reaction zone 22 through a gas pipe and aerated by the first aeration head 222. In this embodiment, the ozone dosage is 200 mg / L, and the micro- and nanobubble particle size is approximately 300 nm. Ozone can directly oxidize pollutants and react with H2O2 and Fe produced during the electro-Fenton process. 3+ Further reactions generate more OH radicals. Electro-Fenton and ozone micro-nano coupling technology promotes Fe production through ozone. 2+ / Fe 3+ The cyclic conversion reduces iron sludge formation by more than 30% compared to the traditional electro-Fenton reaction. Under the synergistic effect of OH free radicals, the molecular structure of organophosphorus pesticides is efficiently destroyed through strong oxidation, and difficult-to-decompose substances such as benzene rings and heterocycles are degraded, reducing the toxicity of wastewater by more than 90% and efficiently removing organic matter from the water, thus providing a guarantee for subsequent biological treatment units.

[0024] Specifically, the pH adjustment tank 3 is equipped with a pH adjustment unit 31, a second stirrer 32, and a second dosing port 33 for adding microbial agents. The pH adjustment unit 31 includes an alkali dosing port 311 and a second pH meter 312. The stirring end of the second stirrer 32 extends into the pH adjustment tank 3, and NaOH solution is quantitatively added as a pH adjuster through the alkali dosing port 311. Under the control of a precision metering pump, the alkali solution is uniformly injected into the wastewater treatment system. In this embodiment, during the dosing process, the second stirrer 32 mechanically stirs at a speed of 120 rpm to ensure that the agent and wastewater are fully mixed and that the reaction system reaches an ideal homogeneous state. This stage, through precise pH control, gradually raises the wastewater from an acidic environment to a slightly alkaline 7.5, creating optimal conditions for subsequent biological treatment. During the adjustment process, the second pH meter 312 installed in the reaction tank performs real-time dynamic monitoring, collecting data every 30 seconds and feeding it back to the central control system to achieve closed-loop control of the pH value. After pH adjustment, a specially acclimatized, acid- and toxic-resistant microbial community is introduced through the second inlet 33. This community includes specific strains such as complex dehydrogenase-producing bacteria and organic pollutant-degrading bacteria. After inoculation, stirring is stopped, allowing the wastewater to enter a 12-hour static bioaugmentation phase. During this process, the microbial community gradually adapts to the environment and proliferates, decomposing recalcitrant organic matter in the wastewater through enzymatic reactions, effectively reducing the wastewater's biotoxicity. Simultaneously, extracellular polymers secreted by the active microorganisms can adsorb some heavy metal ions, further stabilizing water quality indicators. In this embodiment, this pretreatment stage reduces the wastewater's COD toxicity ratio from 0.32 to below 0.15, providing stable influent conditions for the subsequent upflow anaerobic sludge blanket reactor. A booster pump 6 is installed on the connecting pipe between the pH adjustment tank 3 and the anaerobic UASB reactor 4 to transport wastewater from the pH adjustment tank 3 to the anaerobic UASB reactor 4.

[0025] Specifically, the anaerobic UASB reactor 4 is equipped with an anaerobic three-phase separator 41, and an outlet 42 is located at the top of the reactor 4. In this embodiment, the internal temperature of the reactor must be strictly maintained at around 35°C during operation to create a suitable environment for mesophilic anaerobic digestion. After the wastewater enters the reactor, the hydraulic retention time is set to 24 hours to ensure sufficient contact between organic pollutants and anaerobic microorganisms. The system uses a volumetric loading rate of 8 kg COD / (m³). d) Maintaining operational stability while ensuring treatment efficiency. The three-phase separator installed at the top of the tower effectively separates the gas, liquid, and solid phases, promoting the smooth discharge of biogas and ensuring that the anaerobic granular sludge is effectively retained within the reaction zone 22. Under anaerobic conditions, the sludge undergoes three stages in sequence: hydrolysis, acidification, and methanogenesis, gradually decomposing the complex organic matter in the wastewater into small-molecule acids, ultimately converting it into methane and carbon dioxide. The methane is discharged through the gas outlet 42. Through this series of biodegradation processes, the system exhibits excellent treatment performance for high-concentration organic wastewater, with a stable chemical oxygen demand (COD) removal rate exceeding 90%.

[0026] Specifically, the biological treatment tank 5 preferentially adopts anoxic membrane bioreactor technology, including an aerobic biological reaction zone 5122. The aerobic biological reaction zone 5122 is equipped with a membrane separation system 511 and an aeration unit 512. The membrane separation system 511 is existing technology and will not be described in detail here. The aeration unit 512 includes multiple second aeration heads 5121 located at the bottom of the aerobic biological reaction zone 5122. The biological treatment tank 5 is also equipped with a level gauge 52. The biological treatment tank 5 is connected to a discharge pipeline or a reuse pipeline. In this embodiment, the membrane separation system 511 uses multiple hollow fiber membranes or flat sheet membranes with a pore size of 0.05 μm, which can efficiently intercept activated sludge and suspended pollutants. The multiple second aeration heads 5121 are arranged at the bottom of the reaction zone 22 to supply oxygen and create hydraulic disturbance. The system precisely controls the dissolved oxygen gradient through multiple secondary aeration heads 5121, maintaining a high dissolved oxygen level (average of approximately 3 mg / L) in the lower part of the membrane separation system 511, while the average dissolved oxygen level in other areas of the reaction zone 22 is maintained at 0.8 mg / L, thus promoting aerobic metabolism and anoxic reactions respectively. The sludge concentration in the reactor reaches as high as 10,000 mg / L, and the hydraulic retention time is 18 hours, effectively enhancing the pollutant degradation efficiency. The biological treatment tank 5 is also equipped with a level gauge 52 to monitor the operating water level in real time. The treated effluent is discharged through a discharge pipeline or a reuse pipeline, and the water quality can stably meet the strict standards of total phosphorus (TP) below 0.5 mg / L and chemical oxygen demand (COD) below 50 mg / L, satisfying the requirements for discharge or resource reuse.

[0027] Biological tank 5 can also use A 2 Other biological nitrogen and phosphorus removal processes for wastewater, such as O process and MBR process.

[0028] Specifically, sludge discharge valves 7 are installed at the bottom of the coagulation sedimentation tank 1, the electro-Fenton reactor 2, the anaerobic UASB reactor 4, and the biological treatment tank 5. The installation of sludge discharge valves 7 is a key measure for each treatment unit to achieve regular sludge discharge and stable system operation. By periodically opening the sludge discharge valves 7, the excess sludge settled at the bottom of the tanks can be effectively discharged, preventing sludge accumulation, maintaining the effective volume of the reaction zone 22, and ensuring the stability of hydraulic retention time and treatment load. Furthermore, proper sludge discharge also helps control sludge age, optimize the microbial community structure, thereby improving wastewater treatment efficiency and ensuring that the effluent quality meets standards.

[0029] This invention effectively solves the problem of treating phosphorus-containing pesticide wastewater through multi-unit synergistic coupling. The coagulation sedimentation tank 1 effectively removes phosphates and suspended solids, reducing the workload on subsequent units; the electro-Fenton-ozone micro-nano coupling system generates Fe in situ through electrodes. 2+ The system combines ·OH with ozone generated through efficient mass transfer via micro-nano bubbles, synergistically producing a large number of free radicals. This significantly improves the chain breaking and degradation efficiency of recalcitrant organic pollutants, as well as ozone utilization, thereby significantly reducing wastewater toxicity and improving biodegradability. Simultaneously, it reduces the production of iron sludge associated with traditional electro-Fenton processes. In pH adjustment tank 3, the addition of specific bacterial communities rapidly stabilizes water quality, creating a suitable environment for the anaerobic system. Subsequent UASB combined with traditional biological carbon and phosphorus removal processes achieves efficient and stable biodegradation and deep purification of organic matter. The entire system is highly integrated, with a smooth treatment process, strong resistance to shock loads, and consistently meets effluent quality standards. Operating costs are significantly lower than traditional processes.

[0030] 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.

[0031] The embodiments described above are merely illustrative of several implementations of this utility model, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this utility model, and these all fall within the protection scope of this utility model. Therefore, the protection scope of this utility model patent should be determined by the appended claims.

Claims

1. A device for deep treatment of phosphorus-containing pesticide wastewater, characterized in that: The system comprises a coagulation sedimentation tank, an electro-Fenton reaction tank, a pH adjustment tank, an anaerobic UASB reaction tower, and a biological treatment tank, connected in sequence. The coagulation sedimentation tank is equipped with a first dosing port for adding coagulant and a first agitator, with the stirring end of the first agitator extending into the coagulation sedimentation tank. The electro-Fenton reaction tank is equipped with a pH adjustment zone and a reaction zone in sequence along the water flow direction. The pH adjustment zone is equipped with an acid dosing port and a first pH meter. The reaction zone is equipped with an electrode unit and is connected to a gas generating component, which supplies gas to the reaction zone through a gas pipeline. The pH adjustment tank is equipped with a pH adjustment unit, a second agitator, and a second dosing port for adding microbial agents. The pH adjustment unit includes an alkali dosing port and a second pH meter, with the stirring end of the second agitator extending into the pH adjustment tank.

2. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 1, characterized in that: The electrode unit includes several electrode plate groups arranged at intervals. Each electrode plate group includes an anode plate and a cathode plate. The anode plate and the cathode plate are arranged in pairs. The anode plate is an iron plate, and the cathode plate is a carbon felt.

3. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 1, characterized in that: The gas generating assembly includes a micro-nano bubble generator and an ozone generator. One end of the gas pipe is connected to the micro-nano bubble generator and the ozone generator, and the other end of the gas pipe extends into the reaction zone and is connected to a first aeration head located in the reaction zone.

4. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 1, characterized in that: The anaerobic UASB reactor is equipped with an anaerobic three-phase separator, and the top of the anaerobic UASB reactor is equipped with an outlet.

5. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 1, characterized in that: The biochemical tank includes an aerobic biological reaction zone, which is equipped with a membrane separation system and an aeration unit. The membrane separation system is used to intercept activated sludge and suspended pollutants. The aeration unit includes a plurality of second aeration heads, which are located at the bottom of the aerobic biological reaction zone.

6. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 5, characterized in that: The biochemical pool is also equipped with a level gauge.

7. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 1, characterized in that: A booster pump is installed on the connecting pipeline between the pH adjustment tank and the anaerobic UASB reactor.

8. The advanced treatment device for phosphorus-containing pesticide wastewater according to claim 1, characterized in that: The bottom of the coagulation sedimentation tank, the electro-Fenton reactor, the anaerobic UASB reactor, and the biochemical tank are all equipped with sludge discharge valves.

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