An automatic matching type denitrification device for high ammonia-nitrogen wastewater treatment

Abstract

The present application relates to the field of wastewater treatment, and particularly relates to an automatic matching type denitrification device for high ammonia-nitrogen wastewater treatment. The automatic matching type denitrification device for high ammonia-nitrogen wastewater treatment comprises, in sequence, a high ammonia-nitrogen wastewater adjusting tank, a breakpoint chlorination reaction tank, a multifunctional dechlorination tank, a short-cut nitrification tank, an integrated A / O denitrification tank and a biochemical sedimentation tank. The device combines the breakpoint chlorination method with the biological denitrification process, and compared with the conventional biochemical denitrification nitrification-denitrification process, the device has more thorough treatment effect, is not limited by carbon source and temperature, solves the problems of large oxygen consumption and the need for external carbon source in the traditional biological denitrification process, reduces the operation cost, solves the problems of high chlorine consumption and many by-products when the breakpoint chlorination method is used alone, optimizes the chlorine addition ratio, realizes accurate regulation and control of ammonia-nitrogen and chlorine addition amount through online monitoring and automatic control, and improves the automation level.

Description

Technical Field

[0001] This invention relates to the field of wastewater treatment, and more particularly to an automatic blending denitrification device for treating high ammonia nitrogen wastewater. Background Technology

[0002] In recent years, large amounts of wastewater containing nutrients such as nitrogen and phosphorus have been discharged into receiving water bodies, causing eutrophication of surface waters and resulting in algal blooms or red tides. Nitrogen and phosphorus pollution in water bodies causes various algae and plankton to proliferate rapidly, forming a gelatinous coating on the water surface. Simultaneously, dissolved oxygen levels in the water droplets decrease rapidly, leading to mass fish deaths. This phenomenon is called red tide in seawater and algal bloom in freshwater. This problem is becoming increasingly serious worldwide and has become one of the most pressing water environmental issues facing humanity. Most lakes and coastal waters in my country have suffered from eutrophication and red tides for years, causing incalculable economic losses and environmental damage. The main factors causing surface water eutrophication are nitrogen and phosphorus. Algae require approximately 1 / 10 to 1 / 20 of their nitrogen requirement for phosphorus. Therefore, the phosphorus content in water bodies becomes a limiting factor for algal proliferation. Controlling nitrogen and phosphorus emissions from wastewater is therefore a primary means of preventing surface water eutrophication.

[0003] Physical methods for removing nitrogenous pollutants from wastewater mainly include ammonia stripping, electrodialysis, and reverse osmosis; chemical methods mainly include breakpoint chlorination and selective ion exchange; biological methods mainly include nitrification / denitrification and land treatment. Physicochemical denitrification methods generally can only remove specific forms of nitrogen from water, and are complex, costly, and prone to secondary environmental pollution. Regeneration methods are also imperfect, therefore, they are only suitable for treating small to medium volumes of pollutants and are difficult to promote on a large scale. Biological denitrification methods have become mainstream due to their economic, environmental, and simple operation advantages, but traditional nitrification / denitrification processes have long residence times, high oxygen consumption, and require external carbon sources, resulting in high treatment costs. Breakpoint chlorination is a chemical denitrification method that oxidizes ammonia nitrogen to nitrogen gas by adding chlorine or hypochlorite. It has advantages such as fast reaction, thorough removal, and small footprint, but when used alone, it has high chlorine consumption and produces many byproducts. To address these issues, it is urgent to solve the shortcomings of existing methods for treating high-ammonia-nitrogen wastewater to improve denitrification efficiency. Summary of the Invention

[0004] In order to overcome the shortcomings of existing methods for denitrification of high ammonia nitrogen wastewater, which are imperfect and affect the denitrification effect, this invention provides an automatic blending denitrification device for treating high ammonia nitrogen wastewater.

[0005] The technical implementation scheme of the present invention: An automatic adjusting denitrification device for treating high ammonia nitrogen wastewater, comprising a high ammonia nitrogen wastewater equalization tank, a breakpoint chlorination reaction tank, a multi-functional dechlorination tank, a short-cut nitrification tank, an integrated A / O denitrification tank, and a biochemical sedimentation tank connected in sequence; the multi-functional dechlorination tank includes a support platform, a reduction chamber, an inlet pipe, a reducing agent delivery pipe, a sedimentation chamber, a sludge discharge valve, a flocculation chamber, a stirring assembly, an inclined hole filter plate, a flocculant delivery pipe, and a semi-annular baffle; the reduction chamber is located on the left side of the support platform; the inlet pipe and the reducing agent delivery pipe are connected in sequence to the reduction chamber; the sedimentation chamber is located on the right side of the support platform; an overflow channel structure for discharging wastewater is opened on the upper right side of the sedimentation chamber; a device for periodically discharging sediment is installed at the bottom of the sedimentation chamber. The slag discharge valve of the sedimentation chamber; a flocculation chamber is fixedly connected to the upper side of the reduction chamber and the sedimentation chamber; several inlet channels connecting to the reduction chamber are opened on the left side of the flocculation chamber; several outlet micropore structures connecting to the sedimentation chamber are opened on the right side of the flocculation chamber; a sedimentation channel structure connecting to the sedimentation chamber is opened at the bottom of the flocculation chamber; a stirring assembly is installed inside the flocculation chamber; an inclined hole filter plate is fixedly connected to the sedimentation chamber, and the installation height of the inclined hole filter plate is aligned between the overflow channel structure and the outlet micropore structure of the flocculation chamber; a flocculant delivery pipe for conveying flocculant is connected to the flocculation chamber; a semi-circular baffle is provided on the right side of the flocculation chamber; several guide vertical plate structures are provided on the semi-circular baffle; and a guide fan plate structure is provided at the bottom of each guide vertical plate structure.

[0006] Preferably, the high ammonia nitrogen wastewater equalization tank is equipped with a submersible mixer and perforated aeration pipes at the bottom to prevent sludge caking and deposition; the high ammonia nitrogen wastewater equalization tank is equipped with an online ammonia nitrogen monitor to detect ammonia nitrogen concentration; the high ammonia nitrogen wastewater equalization tank is equipped with an online pH monitoring system; the high ammonia nitrogen wastewater equalization tank is equipped with an online TOC analyzer to detect organic matter concentration; the high ammonia nitrogen wastewater equalization tank is equipped with a PLC system to adjust the chlorination dosage and raw water diversion ratio according to the ammonia nitrogen to TOC ratio; the high ammonia nitrogen wastewater equalization tank is equipped with an acid-base dosing device to adjust the pH value; the effluent system of the high ammonia nitrogen wastewater equalization tank is connected to the influent system of the breakpoint chlorination reaction tank.

[0007] Preferably, the inflection point chlorination reactor adopts a baffled structure, forming an up-and-down reversing flow path; a stirrer is installed in the reversing flow channel of the inflection point chlorination reactor; the inflection point chlorination reactor is equipped with an automatic chlorination device; the last flow channel of the inflection point chlorination reactor is equipped with an online pH monitoring system; the last flow channel of the inflection point chlorination reactor is equipped with an ORP meter for monitoring oxidation-reduction potential; the last flow channel of the inflection point chlorination reactor is equipped with an alkali replenishment device; the inflection point chlorination reactor is equipped with a chlorine leak alarm device, which is interlocked with the automatic chlorination device and the alkali replenishment device; the effluent system of the inflection point chlorination reactor is connected to the influent system of the multi-functional dechlorination tank.

[0008] Preferably, the short-cut nitrification tank is equipped with a biological packing layer on which nitrifying bacteria attach and grow; the short-cut nitrification tank is equipped with a blower for oxygen supply; the short-cut nitrification tank is equipped with a microporous aerator; the short-cut nitrification tank is equipped with an online nitrite nitrogen meter; the effluent system of the short-cut nitrification tank is connected to the influent system of the integrated A / O denitrification tank.

[0009] Preferably, the integrated A / O denitrification tank consists of a front-end anoxic zone and a rear-end aerobic zone. The influent system of the integrated A / O denitrification tank is connected to the anoxic zone. The anoxic zone of the integrated A / O denitrification tank is equipped with a submersible mixer and a sludge return pump. The aerobic zone of the integrated A / O denitrification tank is equipped with a biological packing layer on which nitrifying bacteria attach and grow. The aerobic zone of the integrated A / O denitrification tank is equipped with a microporous aerator, an online pH monitoring system, and a dissolved oxygen (DO) meter. The effluent system of the integrated A / O denitrification tank is connected to the influent system of the biological sedimentation tank.

[0010] Preferably, the sludge at the bottom of the biochemical sedimentation tank is treated in three parts: one part is discharged as excess sludge; the second part is returned to the anoxic zone of the integrated A / O denitrification tank by a sludge return pump to maintain the sludge concentration in the biological tank; and the third part is returned to the multifunctional dechlorination tank by another sludge return pump to utilize the reducing properties of the sludge to assist in the removal of residual chlorine and realize the resource utilization of the sludge.

[0011] Preferably, the high ammonia nitrogen wastewater equalization tank is equipped with a bypass effluent system that connects to the anoxic zone of the integrated A / O denitrification tank, and the wastewater in the anoxic zone of the integrated A / O denitrification tank provides a carbon source for denitrification.

[0012] Preferably, the stirring assembly includes a rotating shaft, a stirring motor, outer blades, a first gear, a rotating drum, a second gear, inner blades, and an isolation cover; the rotating shaft is rotatably connected to the upper side of the flocculation chamber; a stirring motor that drives the rotating shaft to rotate is installed on the flocculation chamber; two outer blades are fixedly connected to the rotating shaft; a first gear is fixedly connected to the rotating shaft; a rotating drum is rotatably connected to the lower side of the flocculation chamber; a second gear is fixedly connected to the rotating drum; the second gear meshes with the first gear; three inner blades are fixedly connected inside the rotating drum; an isolation cover is fixedly connected inside the flocculation chamber; both the first gear and the second gear are isolated inside the isolation cover.

[0013] Preferably, the flocculation chamber is equipped with an alkali delivery pipe for adding alkali solution to adjust the pH value; the alkali delivery pipe is connected to several branch pipes; several nozzle structures are opened on the side of the branch pipes facing the water inlet channel structure; a pH detector for monitoring the pH value of wastewater is installed on the left side of the flocculation chamber.

[0014] Preferably, the effluent micropore structure is located in the lower middle region of the flocculation chamber; a C-shaped baffle for shielding the effluent micropore structure is fixed inside the flocculation chamber, the C-shaped baffle being a bucket-shaped structure that tapers towards the center from the bottom; several vertical groove structures are provided on the top of the C-shaped baffle; a sloping bottom plate of C-shaped structure is fixed to the bottom of the C-shaped baffle; an annular pipe is fixed inside the C-shaped baffle; the annular pipe is connected to the output port of the flocculant delivery pipe; several nozzle structures are provided on the upper side of the annular pipe.

[0015] The beneficial effects of this invention are as follows: This invention provides an automatic blending denitrification device for treating high ammonia nitrogen wastewater. The device sequentially connects a high ammonia nitrogen wastewater equalization tank, a breakpoint chlorination reaction tank, a multi-functional dechlorination tank, a short-cut nitrification tank, an integrated A / O denitrification tank, and a biological sedimentation tank. This device combines breakpoint chlorination with biological denitrification. Compared to conventional biological denitrification, nitrification, and denitrification processes, its treatment effect is more thorough, unaffected by carbon source and temperature limitations, and solves the problems of high oxygen consumption and the need for external carbon sources in traditional biological denitrification processes, thus reducing operating costs. It also solves the problems of high chlorine consumption and numerous byproducts when breakpoint chlorination is used alone, and optimizes the chlorine dosage ratio. Through online monitoring and automatic control, the ammonia nitrogen and chlorine dosage can be precisely controlled, improving the level of automation. The multi-functional dechlorination tank used in this device integrates five major functional modules: reduction reaction, intelligent pH adjustment, forced internal circulation staged flocculation, secondary concentration in the sludge discharge section, and flow guidance and anti-disturbance sedimentation. This forms a highly coordinated integrated treatment system from chemical environment control to floc growth and sorting to final solid-liquid separation. While significantly improving the stability of effluent quality and sludge thickening performance, it greatly reduces reagent consumption and operating energy consumption, achieving a comprehensive optimization and upgrade in treatment efficiency, operating economy, and ease of operation and maintenance. Attached Figure Description

[0016] Figure 1 This is a flowchart of an automatic blending denitrification device for treating high ammonia nitrogen wastewater according to the present invention; Figure 2 This is a three-dimensional view of the multi-functional dechlorination tank of this device; Figure 3 This is a three-dimensional cross-sectional view of the reduction chamber and sedimentation chamber of the multifunctional dechlorination tank of this device; Figure 4 This is a three-dimensional view of the flocculation chamber of the multifunctional dechlorination tank in this device; Figure 5 This is a three-dimensional cross-sectional view of the flocculation chamber of the multifunctional dechlorination tank in this device; Figure 6 This is a three-dimensional view of the stirring assembly of the multifunctional dechlorination tank in this device; Figure 7 This is a three-dimensional view of the rotating drum of the multifunctional dechlorination tank in this device; Figure 8This is a three-dimensional view of the semi-annular baffle of the multifunctional dechlorination tank of this device; Figure 9 This is a three-dimensional view of the C-shaped baffle of the multifunctional dechlorination tank of this device.

[0017] Reference numerals: 1-Support platform, 2-Reduction chamber, 21-Inlet pipe, 22-Reducing agent delivery pipe, 3-Sedimentation chamber, 301-Overflow channel structure, 31-Slag discharge valve, 4-Flocculation chamber, 401-Inlet channel structure, 402-Outlet microporous structure, 403-Sedimentation channel structure, 41-Rotating shaft, 42-Stirring motor, 43-Outer blade, 44-First gear, 45-Rotating drum, 46-Second gear, 47-Inner blade, 48-Isolation cover, 5-Inclined hole filter plate, 6-Flocculating agent delivery pipe, 61-Annular pipe, 6101-Nozzle structure, 7-Semi-annular baffle, 701-Guide vertical plate structure, 702-Guide fan plate structure, 8-Alkali delivery pipe, 81-Diverter pipe, 8101-Nozzle structure, 82-pH detector, 9-C-shaped baffle, 901-Vertical trough structure, 91-Sloping bottom plate. Detailed Implementation

[0018] The invention will now be described more fully below with reference to the accompanying drawings, in which presently preferred embodiments of the invention are illustrated. However, the invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided for thoroughness and completeness and to fully convey the scope of the invention to those skilled in the art.

[0019] Example 1: An automatic blending denitrification device for treating high ammonia nitrogen wastewater, as described in this example... Figure 1 As shown, the system is connected in sequence to a high ammonia nitrogen wastewater equalization tank, a breakpoint chlorination reaction tank, a multi-functional dechlorination tank, a short-cut nitrification tank, an integrated A / O denitrification tank, and a biochemical sedimentation tank.

[0020] High-ammonia nitrogen wastewater first enters a high-ammonia nitrogen wastewater equalization tank. The bottom of the equalization tank is equipped with a submersible mixer and perforated aeration pipes to release microbubbles that disturb the bottom sediment, preventing sludge caking and deposition. The equalization tank is equipped with an online ammonia nitrogen monitor to detect ammonia nitrogen concentration; an online pH monitoring system; an online TOC analyzer to detect organic matter concentration; a PLC system to adjust the chlorination dosage and raw water diversion ratio based on the ammonia nitrogen to TOC ratio; and an acid / alkali dosing device to adjust the pH value, stabilizing the effluent pH within the range of 6.5-7.5. The high-ammonia nitrogen wastewater then flows through the effluent system of the equalization tank into the influent system of the inflection point chlorination reactor.

[0021] The inflection point chlorination reactor adopts a baffled structure, forming an up-and-down reversing flow path, extending the water flow path by more than three times. The inflection point chlorination reactor is equipped with an automatic chlorination device for adding sodium hypochlorite solution. Based on the influent ammonia nitrogen and TOC concentrations, sodium hypochlorite solution is added to control the Cl2:NH4 ratio. + The -N mass ratio is 5.5:1 to 7:1; a stirrer is installed in the reversing flow channel of the breakpoint chlorination reactor to ensure thorough mixing of sodium hypochlorite and wastewater; an online pH monitoring system is installed in the last flow channel of the breakpoint chlorination reactor; an ORP meter for monitoring oxidation-reduction potential is installed in the last flow channel of the breakpoint chlorination reactor; an alkali replenishment device is installed in the last flow channel of the breakpoint chlorination reactor; the PLC dynamically adjusts the chlorination dosage based on feedback parameters from each flow channel, and automatically replenishes alkali solution through the alkali replenishment device when the pH drops below 6.0. The pH is maintained at 6.5-7.2. When the ORP rises above 800mV, the chlorination dosage is appropriately reduced to ensure the reaction operates under optimal conditions. The total residence time is controlled at 1-2 hours. The breakpoint chlorination reactor is equipped with a chlorine leak alarm device, which is interlocked with the automatic chlorination device and the alkali replenishment device. When the pH < 5.5 and the ORP rises abnormally, chlorination is automatically stopped and alkali is added urgently. The high ammonia nitrogen wastewater then enters the influent system of the multi-functional dechlorination tank through the effluent system of the breakpoint chlorination reactor.

[0022] like Figures 1-8As shown, the multi-functional dechlorination tank includes a support platform 1, a reduction chamber 2, an inlet pipe 21, a reducing agent delivery pipe 22, a sedimentation chamber 3, a slag discharge valve 31, a flocculation chamber 4, a stirring assembly, an inclined hole filter plate 5, a flocculant delivery pipe 6, and a semi-annular baffle 7. The reduction chamber 2 is located on the left side of the support platform 1. The inlet pipe 21 and the reducing agent delivery pipe 22 are connected sequentially to the reduction chamber 2, with the outlet end of the reducing agent delivery pipe 22 facing the outlet end of the inlet pipe 21. The reducing agent delivery pipe 22 is externally connected to a reducing agent delivery device. The sedimentation chamber 3 is located on the right side of the support platform 1. An overflow channel structure 301 is opened on the upper right side of the sedimentation chamber 3. A slag discharge valve 31 is installed at the bottom of the sedimentation chamber 3. The flocculation chamber 4 is fixedly connected to the upper side of both the reduction chamber 2 and the sedimentation chamber 3. Several inlet channel structures 401 are opened on the left side of the flocculation chamber 4. The inlet end of the flocculation chamber 4 is connected to the reduction chamber 2; several outlet micropore structures 402 are provided on the right side of the flocculation chamber 4, and the outlet end of the outlet micropore structure 402 is connected to the sedimentation chamber 3; a sedimentation channel structure 403 is provided at the bottom of the flocculation chamber 4, which is connected to the sedimentation chamber 3, and the outlet end of the sedimentation channel structure 403 is connected to the sedimentation chamber 3; a stirring assembly is installed inside the flocculation chamber 4; an inclined hole filter plate 5 is fixedly connected to the sedimentation chamber 3, and the installation height of the inclined hole filter plate 5 is aligned between the overflow channel structure 301 and the outlet micropore structure 402 of the flocculation chamber 4; a flocculant delivery pipe 6 is connected to the flocculation chamber 4, and a flocculant delivery device is connected to the outside of the flocculant delivery pipe 6; a semi-annular baffle 7 is provided on the right side of the flocculation chamber 4; several guide vertical plate structures 701 are provided on the semi-annular baffle 7; and a guide fan plate structure 702 is provided at the bottom of each guide vertical plate structure 701.

[0023] During wastewater treatment in the multifunctional dechlorination tank of this embodiment, the wastewater enters the reduction chamber 2 through the inlet pipe 21 of the inlet system of the multifunctional dechlorination tank. At the same time, the external reducing agent delivery device continuously delivers reducing agent to the outlet port of the inlet pipe 21 through the reducing agent delivery pipe 22, allowing the wastewater and reducing agent to mix thoroughly and undergo a reduction reaction. After the reduction reaction is completed, the wastewater flows upward through the inlet channel structure 401 and enters the flocculation chamber 4. At the same time, the external flocculant delivery device delivers flocculant into the flocculation chamber 4 through the flocculant delivery pipe 6. The stirring component thoroughly stirs the wastewater and flocculant in the flocculation chamber 4, causing the precipitated particles in the wastewater to continuously flocculate and accumulate into large-volume precipitates. Under the action of their own gravity, the large-volume precipitates sink downward through the sedimentation channel structure 403 to the bottom of the sedimentation chamber 3. Meanwhile, the wastewater that has separated the precipitate in the flocculation chamber 4 exits through the effluent. The microporous structure 402 flows out to the right. The wastewater flowing out of the microporous structure 402 is intercepted by the semi-annular baffle 7 and flows downward along the guide vertical plate structure 701. After leaving the bottom of the semi-annular baffle 7, the wastewater flows to the upper right side along the guide fan plate structure 702 towards the inclined hole filter plate 5. Under the flow guidance of the guide vertical plate structure 701 and the guide fan plate structure 702, the unstable turbulence generated by the wastewater during the flow can be reduced, and the disturbance caused to the sediment at the bottom of the sedimentation tank 3 can be reduced. When the wastewater flows upward through the inclined hole filter plate 5, the inclined hole filter plate 5 intercepts and filters the small amount of small-volume sediment remaining in the wastewater. Finally, only the clarified wastewater passes through the inclined hole filter plate 5 and flows out through the overflow channel structure 301 in the effluent system of the multi-functional dechlorination tank. In addition, during regular maintenance, the sludge discharge valve 31 can be opened to discharge the sediment at the bottom of the sedimentation tank 3.

[0024] The short-cut nitrification tank is equipped with a biological packing layer on which nitrifying bacteria attach and grow. It also features a blower for oxygen supply and a microporous aerator that turns air into tiny bubbles, increasing the oxygen contact area and utilization rate, and controlling dissolved oxygen at 1.5-2.5 mg / L. This process partially oxidizes residual ammonia nitrogen into nitrite nitrogen. An online nitrite nitrogen meter is also installed to monitor the short-cut nitrification effect. High-ammonia nitrogen wastewater then enters the influent system of the integrated A / O denitrification tank through the effluent system of the short-cut nitrification tank.

[0025] The integrated A / O denitrification tank consists of a pre-anoxic zone and a post-aerobic zone. The influent system of the integrated A / O denitrification tank is connected to the anoxic zone. The anoxic zone of the integrated A / O denitrification tank is equipped with a submersible mixer. The anoxic zone of the integrated A / O denitrification tank is also equipped with a sludge return pump to receive some of the excess sludge from the biological sedimentation tank, maintaining the sludge concentration in the anoxic zone at 3000–5000 mg / L and controlling dissolved oxygen below 0.5 mg / L. Denitrifying bacteria utilize organic matter in the raw water to reduce nitrite and nitrate nitrogen to nitrogen gas for removal. The high ammonia nitrogen wastewater equalization tank has a bypass effluent system connected to the anoxic zone of the integrated A / O denitrification tank. The wastewater in the anoxic zone of the integrated A / O denitrification tank provides a carbon source for denitrification. The aerobic zone of the integrated A / O denitrification tank is equipped with a biological packing layer on which nitrifying bacteria attach and grow. The aerobic zone of the integrated A / O denitrification tank also features microporous aerators to maintain dissolved oxygen at 2-3 mg / L, oxidizing residual ammonia nitrogen into nitrate nitrogen. The nitrified liquor in the aerobic zone of the integrated A / O denitrification tank is returned to the front end of the anoxic zone via a mixed liquor return pump, with a return ratio controlled at 100%-300%, ultimately removing total nitrogen. The aerobic zone of the integrated A / O denitrification tank is equipped with an online pH monitoring system and a dissolved oxygen (DO) meter. The denitrified wastewater then enters the influent system of the biological sedimentation tank through the effluent system of the integrated A / O denitrification tank.

[0026] The sludge at the bottom of the biological sedimentation tank is treated in three parts: one part is discharged as excess sludge; the second part is returned to the anoxic zone of the integrated A / O denitrification tank through a sludge return pump to maintain the sludge concentration in the biological tank; and the third part is returned to the multi-functional dechlorination tank through another sludge return pump to utilize the reducing properties of the sludge to assist in the removal of residual chlorine and realize the resource utilization of the sludge.

[0027] The following sections provide detailed explanations of each part.

[0028] The main function of the high ammonia nitrogen wastewater equalization tank is to regulate the water quality and quantity. It is equipped with instruments such as an online pH meter, an online ammonia nitrogen meter, and an online TOC analyzer.

[0029] In the breakpoint chlorination reaction tank, sodium hypochlorite, as a chlorine-based oxidant, reacts with ammonia nitrogen in water to oxidize it into nitrogen gas. The reaction mechanism is as follows: When sodium hypochlorite is added to water, it first reacts with water to produce hypochlorous acid: NaOCl + H₂O → HOCl + NaOH Hypochlorous acid undergoes a series of oxidation reactions with ammonia nitrogen: Phase 1: Ammonia nitrogen is oxidized to monochloramine. HOCl + NH4 + →NH₂Cl + H₂O + H₂ + Second stage: Monochloramine is further oxidized to dichloramine. NH₂Cl + HOCl → NH₂ + H₂O Third stage: Dichloramine continues to be oxidized to trichloramine. NHCl2 + HOCl → NCl3 + H2O Fourth stage: Chloramine is eventually oxidized to nitrogen gas, which is the core reaction for removing ammonia nitrogen by breakpoint chlorination. 2NH₂Cl + HOCl → N₂↑ + 3HCl + H₂O Controlling the Cl:NH3 ratio to 5.5-7:1 ensures the reaction approaches but does not exceed the breakpoint, avoiding the generation of large amounts of free residual chlorine and reducing dechlorination costs.

[0030] The effluent from the inflection point chlorination reactor flows into the multi-functional dechlorination tank. The multi-functional dechlorination tank has an overall water flow direction of bottom inlet, zoned treatment, and top outlet. Through the organic integration of five functional modules, namely reduction reaction, intelligent pH adjustment, forced internal circulation staged flocculation, secondary concentration in the sludge discharge section, and flow guidance and anti-disturbance sedimentation, a highly coordinated integrated treatment system is formed, from chemical environment control to floc growth and sorting to final solid-liquid separation. While significantly improving the stability of effluent water quality and sludge thickening performance, it greatly reduces reagent consumption and operating energy consumption, and achieves a comprehensive optimization and upgrade in treatment efficiency, operating economy, and ease of operation and maintenance.

[0031] The outlet system of the multi-functional dechlorination tank is equipped with an online residual chlorine meter and an ORP meter to ensure that the residual chlorine in the effluent is below 0.05 mg / L and the ORP is < 200 mV. If the residual chlorine exceeds the standard, sodium bisulfite will be automatically added through the emergency reducing agent dosing device.

[0032] The chemical dechlorination reaction mechanism is as follows.

[0033] When the residual chlorine exceeds the standard, the added reducing agent sodium bisulfite undergoes a redox reaction with the residual chlorine: NaHSO3 + HOCl → NaHSO4 + HCl The effluent from the multi-functional dechlorination tank flows by gravity into the short-cut nitrification tank. The short-cut nitrification tank utilizes the inherent differences in the kinetic characteristics of nitrifying bacteria and nitrite-oxidizing bacteria to control the nitrification reaction to proceed only up to NO2. - The -N stage generates a large amount of NO2. - -N accumulation, its reaction formula is as follows.

[0034] Short-range nitration reaction formula: NH4 + +1.5O2→NO2 - +H₂O+2H + The effluent from the short-cut nitrification tank directly enters the anoxic zone of the integrated A / O denitrification tank, without the installation of a nitrite nitrogen return pipeline.

[0035] The integrated A / O denitrification tank consists of a front anoxic zone and a rear aerobic zone. Denitrification occurs in the anoxic zone. Denitrifying bacteria use organic matter in the raw water as electron donors to reduce nitrite and nitrate nitrogen to gaseous nitrogen (N2) for removal. The denitrification reaction formula is as follows.

[0036] Nitrite denitrification: 2NO2 - +6[H] (electron donor) N₂↑ + 2H₂O + 2OH⁻ - Nitrate denitrification: 2NO3 - +10[H] (electron donor) N₂↑ + 4H₂O + 2OH⁻ - The effluent from the anoxic zone flows into the aerobic zone, where nitrification occurs. Under aerobic conditions, nitrifying bacteria utilize inorganic carbon sources to oxidize residual ammonia nitrogen into nitrite nitrogen, and then further oxidize it into nitrate nitrogen. The nitrification reaction formula is as follows: Nitrification stage (ammonia oxidation to nitrite): NH4 + +1.382O2 + 1.982HCO3 - →0.982NO2 - +1.036H2O+1.891H2CO3+0.018C5H7O2N Nitrification stage (nitrite is oxidized to nitrate): NO2 - +0.488O2 + 0.01H2CO3 + 0.003NH4 + →NO3 - +0.08H2O+0.03C5H7O2N The overall reaction equation for nitration is: NH4 + +1.87O2 +1.982HCO3 - →0.982NO3 - +1.044H2O+1.881H2CO3+0.021C5H7O2N The nitrified liquor from the aerobic zone is returned to the front end of the anoxic zone via a mixed liquor reflux pump, with the reflux ratio controlled at 100%~300%, ultimately removing total nitrogen.

[0037] The effluent from the aerobic zone of the integrated A / O denitrification tank enters the biochemical sedimentation tank through the central guide tube, where mud and water are separated by inclined tube packing, and the supernatant is discharged after meeting the standards.

[0038] Example 2, based on Example 1, such as Figures 1-8 As shown, the multifunctional dechlorination tank of this embodiment includes a stirring assembly comprising a rotating shaft 41, a stirring motor 42, outer blades 43, a first gear 44, a rotating drum 45, a second gear 46, inner blades 47, and an isolation cover 48. The rotating shaft 41 is rotatably connected to the upper side of the flocculation chamber 4. The stirring motor 42 is installed on the flocculation chamber 4. The output shaft of the stirring motor 42 is fixedly connected to the rotating shaft 41. Two outer blades 43 are fixedly connected to the rotating shaft 41. The first gear 44 is fixedly connected to the rotating shaft 41. The rotating drum 45 is rotatably connected to the lower side of the flocculation chamber 4. The second gear 46 is fixedly connected to the rotating drum 45. The second gear 46 meshes with the first gear 44. Three inner blades 47 are fixedly connected inside the rotating drum 45. An isolation cover 48 is fixedly connected inside the flocculation chamber 4. Both the first gear 44 and the second gear 46 are isolated and protected within the isolation cover 48 to prevent sediment in the wastewater from becoming stuck between the first gear 44 and the second gear 46.

[0039] During the wastewater treatment in the multifunctional dechlorination tank of this embodiment, the wastewater enters the flocculation chamber 4 through the inlet channel structure 401. The stirring motor 42 drives the rotating shaft 41 and the outer blades 43 to rotate slowly. At the same time, the flocculant is transported into the flocculation chamber 4 through the flocculant delivery pipe 6. The outer blades 43 stir and mix the wastewater and flocculant in the flocculation chamber 4. The sediment gradually flocculates during the stirring and flocculation process to form a large volume of sediment with a high weight. The large volume sediment slowly moves downward into the rotating drum 45 in the sedimentation channel structure 403 under its own action. At the same time, the rotating shaft 41 drives the first gear 44 to rotate. The first gear 44 meshes with the second gear 46 to drive the rotating drum 45 and the inner blades 47 to rotate. The inner blades 47 drive the large volume sediment passing through the rotating drum 45 to rotate and mix, allowing the large volume sediment to further flocculate together to form a more stable sediment floc. Finally, the sediment floc settles at the bottom of the sedimentation chamber 3.

[0040] Example 3, based on Example 2, such as Figures 1-8 As shown, in this embodiment of the multifunctional dechlorination tank, an alkali solution delivery pipe 8 is installed on the flocculation chamber 4. The lower side of the alkali solution delivery pipe 8 is located inside the flocculation chamber 4, and the alkali solution delivery pipe 8 is connected to an alkali solution delivery device. Several branch pipes 81 are connected to the lower side of the alkali solution delivery pipe 8. Several nozzle structures 8101 are opened on the side of each branch pipe 81 facing the water inlet channel structure 401. A pH value detector 82 is installed on the left side of the flocculation chamber 4.

[0041] During wastewater treatment in the multifunctional dechlorination tank of this embodiment, before the wastewater flows through the inlet channel structure 401 into the flocculation chamber 4, the pH value of the wastewater entering the flocculation chamber 4 is monitored by the pH value detector 82. This automatically calculates the amount of alkali solution that the external alkali solution delivery equipment needs to add to the flocculation chamber 4 through the alkali solution delivery pipe 8. The alkali solution flows along the alkali solution delivery pipe 8 to each branch pipe 81, and then is sprayed out through the nozzle structure 8101 of each branch pipe 81 towards the wastewater flowing into the corresponding inlet channel structure 401. The alkaline solution collides with the wastewater flowing in from the inlet channel structure 401, which not only slows down the flow rate of the wastewater after it flows into the flocculation chamber 4, significantly reducing the impact and disturbance of the wastewater flow on the already formed agitated flocculation environment in the flocculation chamber 4, but also allows the wastewater and alkaline solution to come into full contact and mix efficiently. This operation step realizes the immediate response to the fluctuation of the wastewater pH value and precise quantitative alkali replenishment, reducing the phenomenon of deterioration of flocculation effect or waste of reagents caused by drastic changes in wastewater pH, and stabilizing the reaction environment of the entire flocculation chamber 4 within the optimal flocculation pH range in the shortest possible time.

[0042] Example 4, based on Example 3, such as Figures 1-9 As shown, in this embodiment of the multifunctional dechlorination tank, each effluent microporous structure 402 is located in the lower middle region of the flocculation chamber 4; a C-shaped baffle 9 is fixedly connected inside the flocculation chamber 4, the C-shaped baffle 9 is designed as a bucket-shaped structure that converges from the bottom to the center, the C-shaped baffle 9 covers the effluent microporous structure 402; the top of the C-shaped baffle 9 is provided with several vertical groove structures 901 that are close to the inner wall of the flocculation chamber 4; the bottom of the C-shaped baffle 9 is fixedly connected with a C-shaped sloping bottom plate 91; an annular pipe 61 is fixedly connected to the lower inner side of the C-shaped baffle 9; the annular pipe 61 is connected to the output port of the flocculant delivery pipe 6; several nozzle structures 6101 are provided on the upper side of the annular pipe 61.

[0043] During wastewater treatment in the multifunctional dechlorination tank of this embodiment, as the stirring motor 42 drives the outer blades 43 on the rotating shaft 41 to rotate and stir the wastewater in the flocculation chamber 4, the outer blades 43 continuously push the wastewater located in the middle of the flocculation chamber 4 downwards. Since the depth of the sedimentation channel structure 403 is deeper than the depth of the outlet microporous structure 402 on the inner wall of the flocculation chamber 4, the flow resistance encountered by the wastewater flowing towards the sedimentation channel structure 403 is greater than the flow resistance encountered by the wastewater flowing upwards along the inner wall of the flocculation chamber 4. Therefore, some wastewater will preferentially flow upwards along the inner wall of the flocculation chamber 4, causing the produced sediment to circulate internally within the flocculation chamber 4 along with the undischarged wastewater. The sediment is blocked by the sloping bottom plate 91 and the C-shaped baffle 9 and will not flow directly to the outlet microporous structure 402 of the flocculation chamber 4. When the sediment flows through the sloping bottom plate 91 with the circulating wastewater, if the sediment has already flocculated into a large volume of sediment with a higher weight, the sediment will slide directly down the slope of the sloping bottom plate 91 into the rotating drum 45 for discharge. If the sedimentation is not complete and flocculation is still... When the sediment is in a small volume with relatively light weight, the circulating wastewater will push the small volume sediment upward through the C-shaped baffle 9. At the same time, the flocculant in the flocculant delivery pipe 6 will be sprayed out along the inner surface of the C-shaped baffle 9 through the nozzle structures 6101 of the annular pipe 61. The upward sprayed flocculant will push the small volume sediment upward to participate in the flocculation treatment again. At this time, the sprayed flocculant directly contacts the small volume sediment, realizing the direct targeted replenishment of the unqualified sediment. The small volume sediment is coated with high concentration of agent in the rising stage, which greatly increases the collision probability and coagulation efficiency between small volume sediments, significantly improves the agent utilization rate and sediment discharge concentration, and reduces the waste caused by excessive dosing of agents into the entire flocculation chamber 4. When some small volume sediment flows with the wastewater to the space between the C-shaped baffle 9 and the inner wall of the flocculation chamber 4, some of the upward flowing wastewater will push the small volume sediment through the vertical groove structure 901 and leave the C-shaped baffle 9, avoiding the sediment from accumulating between the C-shaped baffle 9 and the inner wall of the flocculation chamber 4 and causing blockage of the effluent microporous structure 402.

[0044] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that variations may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. An automatic blending denitrification device for treating high ammonia nitrogen wastewater, characterized in that: The system is connected in sequence to a high ammonia nitrogen wastewater conditioning tank, a breakpoint chlorination reaction tank, a multi-functional dechlorination tank, a short-cut nitrification tank, an integrated A / O denitrification tank, and a biochemical sedimentation tank. The multi-functional dechlorination tank includes a support platform (1), a reduction chamber (2), an inlet pipe (21), a reducing agent delivery pipe (22), a sedimentation tank (3), a slag discharge valve (31), a flocculation chamber (4), a stirring assembly, an inclined hole filter plate (5), a flocculant delivery pipe (6), and a semi-circular baffle (7). The left side of the support platform (1) is equipped with a reduction chamber (2). The inlet pipe (21) and the reducing agent delivery pipe (22) are connected in sequence on the reduction chamber (2). The right side of the support platform (1) is equipped with a sedimentation chamber (3). An overflow channel structure (301) for discharging wastewater is opened on the upper right side of the sedimentation chamber (3). A slag discharge valve (31) for periodically discharging sediment is installed at the bottom of the sedimentation chamber (3). A flocculation valve is fixedly connected between the upper sides of the reduction chamber (2) and the sedimentation chamber (3). The flocculation chamber (4) has several inlet channels (401) on the left side that connect to the reduction chamber (2); several outlet micropore structures (402) on the right side that connect to the sedimentation chamber (3); a sedimentation channel structure (403) connecting to the sedimentation chamber (3) is provided at the bottom of the flocculation chamber (4); a stirring assembly is installed inside the flocculation chamber (4); a slanted hole filter plate (5) is fixedly connected to the sedimentation chamber (3), and the installation height of the slanted hole filter plate (5) is aligned between the overflow channel structure (301) and the outlet micropore structure (402) of the flocculation chamber (4); a flocculant delivery pipe (6) for conveying flocculant is connected to the flocculation chamber (4); a semi-ring baffle (7) is provided on the right side of the flocculation chamber (4); several guide vertical plate structures (701) are provided on the semi-ring baffle (7); and a guide fan plate structure (702) is provided at the bottom of each guide vertical plate structure (701).

2. The automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The high ammonia nitrogen wastewater equalization tank is equipped with a submersible mixer and perforated aeration pipes at the bottom to prevent sludge caking and deposition; it also features an online ammonia nitrogen monitor to detect ammonia nitrogen concentration; an online pH monitoring system; an online TOC analyzer to detect organic matter concentration; a PLC system to adjust the chlorination dosage and raw water diversion ratio based on the ammonia nitrogen to TOC ratio; an acid / alkali dosing device to adjust the pH value; and the effluent system of the high ammonia nitrogen wastewater equalization tank is connected to the influent system of the breakpoint chlorination reaction tank.

3. The automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The inflection point chlorination reactor adopts a baffled structure, forming an up-and-down reversible flow path; a stirrer is installed in the reversible flow channel of the inflection point chlorination reactor; the inflection point chlorination reactor is equipped with an automatic chlorination device; the last flow channel of the inflection point chlorination reactor is equipped with an online pH monitoring system; the last flow channel of the inflection point chlorination reactor is equipped with an ORP meter for monitoring oxidation-reduction potential; the last flow channel of the inflection point chlorination reactor is equipped with an alkali replenishment device; the inflection point chlorination reactor is equipped with a chlorine leak alarm device, which is interlocked with the automatic chlorination device and the alkali replenishment device; the effluent system of the inflection point chlorination reactor is connected to the influent system of the multi-functional dechlorination tank.

4. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The short-cut nitrification tank is equipped with a biological packing layer on which nitrifying bacteria attach and grow; the short-cut nitrification tank is equipped with a blower for oxygen supply; the short-cut nitrification tank is equipped with a microporous aerator; the short-cut nitrification tank is equipped with an online nitrite nitrogen meter; the effluent system of the short-cut nitrification tank is connected to the influent system of the integrated A / O denitrification tank.

5. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The integrated A / O denitrification tank consists of a front-end anoxic zone and a rear-end aerobic zone, and the inlet system of the integrated A / O denitrification tank is connected to the anoxic zone; The integrated A / O denitrification tank has a submersible mixer in its anoxic zone; a sludge return pump in its anoxic zone; a biological packing layer in its aerobic zone, on which nitrifying bacteria attach and grow; a microporous aerator in its aerobic zone; an online pH monitoring system in its aerobic zone; a DO meter in its aerobic zone to monitor dissolved oxygen concentration; and an effluent system connected to the influent system of the biological sedimentation tank.

6. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The sludge at the bottom of the biological sedimentation tank is treated in three parts: one part is discharged as excess sludge. The second part is returned to the anoxic zone of the integrated A / O denitrification tank via a sludge return pump to maintain the sludge concentration in the biological tank; the third part is returned to the multi-functional dechlorination tank via another sludge return pump, utilizing the reducing properties of the sludge to assist in the removal of residual chlorine and realize the resource utilization of the sludge.

7. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The high ammonia nitrogen wastewater equalization tank is equipped with a bypass effluent system that connects to the anoxic zone of the integrated A / O denitrification tank. The wastewater in the anoxic zone of the integrated A / O denitrification tank provides a carbon source for denitrification.

8. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The stirring assembly includes a rotating shaft (41), a stirring motor (42), outer blades (43), a first gear (44), a rotating drum (45), a second gear (46), inner blades (47), and an isolation cover (48); the rotating shaft (41) is rotatably connected to the upper side of the flocculation chamber (4); the stirring motor (42) that drives the rotating shaft (41) to rotate is installed on the flocculation chamber (4); two outer blades (43) are fixedly connected to the rotating shaft (41); the first gear (44) is fixedly connected to the rotating shaft (41); the rotating drum (45) is rotatably connected to the lower side of the flocculation chamber (4); the second gear (46) is fixedly connected to the rotating drum (45); the second gear (46) meshes with the first gear (44); three inner blades (47) are fixedly connected inside the rotating drum (45); the isolation cover (48) is fixedly connected inside the flocculation chamber (4); the first gear (44) and the second gear (46) are both isolated inside the isolation cover (48).

9. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The flocculation chamber (4) is equipped with an alkali delivery pipe (8) for adding alkali solution to adjust the pH value; the alkali delivery pipe (8) is connected to several branch pipes (81); the branch pipes (81) have several nozzle structures (8101) on the side facing the water inlet channel structure (401); a pH detector (82) for monitoring the pH value of wastewater is installed on the left side of the flocculation chamber (4).

10. An automatic blending denitrification device for treating high ammonia nitrogen wastewater according to claim 1, characterized in that: The effluent microporous structure (402) is located in the middle and lower part of the flocculation chamber (4); a C-shaped baffle (9) for shielding the effluent microporous structure (402) is fixed inside the flocculation chamber (4). The C-shaped baffle (9) is designed as a bucket-shaped structure that converges from the bottom to the middle; several vertical groove structures (901) are opened on the top of the C-shaped baffle (9); a sloping bottom plate (91) of C-shaped structure is fixed to the bottom of the C-shaped baffle (9); an annular pipe (61) is fixed inside the C-shaped baffle (9); the annular pipe (61) is connected to the output port of the flocculant delivery pipe (6); several nozzle structures (6101) are provided on the upper side of the annular pipe (61).

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