High ammonia-nitrogen wastewater treatment device and treatment method

Abstract

The application relates to the technical field of wastewater treatment, and specifically discloses a high-ammonia-nitrogen wastewater treatment device and a treatment method, which comprises a tank body, a water distributor and a gas outlet are arranged at the top of the tank body, a water outlet is arranged at the bottom end of the tank body, filler and a gas blowing assembly are arranged in the tank body, an outer cylinder and an inner cylinder are coaxially arranged in the tank body, two spiral plates are arranged between the outer cylinder and the inner cylinder, the two spiral plates separate the space between the outer cylinder and the inner cylinder into a filler cavity and a water distribution cavity, the water distribution range of the water distributor is equal to the range of the projection of the filler cavity on a horizontal plane, the outer cylinder, the inner cylinder and the spiral plates are all porous structures, the gas blowing assembly comprises a spiral pipeline arranged outside the outer cylinder and a blowing device, water flow circulates between the filler cavity and the water distribution cavity multiple times, the gas-liquid contact time and frequency are increased, the ammonia-nitrogen stripping effect is improved, the treated wastewater is discharged from the water outlet at the bottom of the tank body, and the gas carrying ammonia gas is discharged from the top gas outlet.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of wastewater treatment, in particular to a high-ammonia-nitrogen wastewater treatment device and a treatment method. BACKGROUND

[0002] Ammonia-nitrogen wastewater is widely sourced and has a large discharge amount, for example, a large amount of high-concentration ammonia-nitrogen wastewater is generated in the production of chemical fertilizers, coking, petrochemicals, pharmaceuticals, food, and landfill sites. Discharging a large amount of ammonia-nitrogen wastewater into water bodies not only causes water body eutrophication and blackening and stench, but also increases the difficulty and cost of water treatment, and even has toxic effects on the human population and organisms. How to prevent and eliminate the influence of ammonia-nitrogen on the ecological environment is one of the main tasks of water treatment researchers at present. In the treatment of high-ammonia-nitrogen wastewater, the general treatment link is: pretreatment + stripping + biochemical treatment. For wastewater containing high ammonia-nitrogen and high COD, most of the ammonia-nitrogen is usually removed by stripping to reduce the toxic load on the subsequent biochemical system, and then the wastewater after stripping is sent to a biological treatment system to remove COD and residual ammonia-nitrogen. The ammonia-nitrogen stripping tower is a physical and chemical treatment technology for removing ammonia-nitrogen in wastewater by using Henry's law and gas-liquid mass transfer principle. Under alkaline conditions (usually the pH value of wastewater is adjusted to above 10.5), a large amount of dissolved and non-volatile ammonium ions in wastewater is converted into free ammonia molecules. The ammonia-nitrogen stripping tower provides a large gas-liquid contact area, and the pretreated high-pH wastewater is in countercurrent contact with air (or steam). Since the ammonia partial pressure in the gas phase is much lower than that in the liquid phase, the free ammonia molecules will diffuse and transfer from the liquid phase (water) to the gas phase (air / steam), and the continuous blowing of fresh air (or steam) continuously carries away the ammonia in the gas phase, maintains a low ammonia partial pressure in the gas phase, and continuously drives the transfer of ammonia from water to air, so as to achieve the purpose of removing ammonia-nitrogen.

[0003] A patent file with the authorization announcement number CN212174502U discloses an ammonia-nitrogen stripping tower, which comprises a shell, an air outlet pipe and a water outlet pipe, a filler part, a water inlet mechanism and an air inlet pipe. The shell is a hollow sealed body. The air outlet pipe and the water outlet pipe are in sealed communication with the inside of the top and the bottom of the shell, respectively. The filler part is installed in the shell and located between the air outlet pipe and the water outlet pipe. The water inlet mechanism is in sealed communication with the shell and located between the air outlet pipe and the filler part. The air inlet pipe is in sealed communication with the inside of the shell and is installed in the shell at an angle of 30-50 degrees from top to bottom. The pipe opening of the air inlet pipe is aligned with the bottom of the shell. The air inlet pipe enters the shell and uniformly impacts the bottom of the shell. The air is uniformly dispersed in the shell to form a horizontal layer and synchronously rises. The water droplets fall from the filler part. The air in the horizontal layer synchronously rises and completely contacts the sewage at each point, completes the mass transfer process, and makes the ammonia-nitrogen completely transfer from the liquid phase to the gas phase and be discharged through the air outlet pipe.

[0004] In order to achieve a certain removal efficiency, the stripping tower needs a large enough gas-liquid contact area and contact time, which directly determines the height of the packing layer. At the same time, a too high tower will increase the construction cost, the operating energy consumption (especially the energy consumption of the fan to overcome the pressure drop) and the structural stability requirement. In addition, the gas flow of the traditional stripping tower is blown from the bottom upwards, and the wastewater flows from top to bottom. Therefore, when the gas flow passes through the bottommost packing layer, a part of ammonia gas in the gas flow is carried. As the gas flow rises, the ammonia content in the gas flow gradually increases. Therefore, when the partial pressure of ammonia in the gas flow is no longer much lower than the partial pressure of ammonia in the liquid phase, the stripping effect of the gas flow on the wastewater at the top will be greatly weakened, thus resulting in poor treatment effect. SUMMARY

[0005] The present application provides a high ammonia-nitrogen wastewater treatment device and method, aiming to solve the problem of poor treatment effect caused by the fact that when the partial pressure of ammonia in the gas flow is no longer much lower than the partial pressure of ammonia in the liquid phase, the stripping effect of the gas flow on the wastewater at the top will be greatly weakened.

[0006] A high ammonia-nitrogen wastewater treatment device, comprising a tank body, a water distributor and a gas outlet are arranged at the top of the tank body, a water outlet is arranged at the bottom end of the tank body, a packing and a gas blowing assembly are arranged in the tank body, an outer cylinder and an inner cylinder are coaxially arranged in the tank body, two spiral plates are arranged between the outer cylinder and the inner cylinder, the two spiral plates separate the space between the outer cylinder and the inner cylinder into a packing cavity and a water distribution cavity, the water distribution range of the water distributor is equal to the projection range of the packing cavity on the horizontal plane, the outer cylinder, the inner cylinder and the spiral plates are all porous structures, the gas blowing assembly comprises a spiral pipe arranged outside the outer cylinder and a blowing device, the pitch of the spiral pipe is the same as that of the spiral plate, and blow heads for blowing gas into the packing cavity are arranged at equal intervals on the spiral pipe, a spiral baffle group is arranged on the inner side of the inner cylinder, the spiral baffle group gradually inclines downward from the position close to the axis of the tank body to the position away from the axis of the tank body, and the outer end of the spiral baffle group enters the water distribution cavity, so as to guide the water flow blown out by the gas flow into the water distribution cavity along the spiral baffle.

[0007] The effect is that the high ammonia-nitrogen wastewater enters the packing cavity from the water distributor. In the packing cavity, the wastewater fully contacts with the packing, the water surface area is increased, which is beneficial to the ammonia gas in the liquid phase entering the gas phase. The liquid flows downward, the blowing device blows gas into the packing cavity through the spiral pipe, the gas flow fully contacts with the wastewater in the packing cavity, the ammonia gas is transferred from the liquid phase to the gas phase, part of the water is blown out of the packing cavity and flows into the water distribution cavity along the spiral baffle, the water in the water distribution cavity enters the packing cavity again to participate in the stripping process, and the water flow circulates between the packing cavity and the water distribution cavity multiple times, which increases the gas-liquid contact time and frequency, improves the ammonia-nitrogen stripping effect, and the treated wastewater is discharged from the water outlet at the bottom of the tank body, and the gas carrying ammonia is discharged from the gas outlet at the top.

[0008] Preferably, the spiral plate is provided with water filtering holes along the spiral direction, and the length direction of the water filtering holes is the same as the width direction of the spiral plate, which can disperse the water flow and further increase the gas-liquid contact area. When the wastewater flows in the filler cavity, the water filtering holes can prevent the local accumulation of water in the filler cavity, and prevent the wastewater from flowing downward along the spiral plate and passing between the filler cavity and the water distribution cavity, so that the wastewater cannot be effectively contacted with the gas, affecting the ammonia nitrogen stripping effect.

[0009] Preferably, the spiral baffle group is composed of spiral baffles one and spiral baffles two with the same pitch, the number of spiral baffles one is at least one, and there are passages between spiral baffles one and spiral baffles two for gas to pass through, and spiral baffles one are completely located in the inner cylinder, so that the gas can flow smoothly in the inner cylinder, ensuring the smooth progress of the gas-liquid mass transfer process. When the gas flow carries ammonia gas, the gas passes through the gap between spiral baffles one and spiral baffles two, and can make the water droplets in the gas flow contact with spiral baffles one and spiral baffles two when passing through these passages, so that the water droplets gather on spiral baffles one and spiral baffles two, and then enter the water distribution cavity through spiral baffles two, and then enter the filler cavity from the water distribution cavity, and then experience gas blowing again until the water flow falls to the bottom of the tank body.

[0010] Preferably, spiral baffles one and spiral baffles two overlap in the projection plane of the tank body axis, and spiral baffles one and spiral baffles two also overlap in the projection plane of the tank body axis. Because of the overlapping area between the spiral baffles, the water droplets in the gas flow can impact on spiral baffles one and spiral baffles two, so as to be separated from the gas flow.

[0011] Preferably, the upper surfaces of spiral baffles one and spiral baffles two are provided with a plurality of equally spaced hydrophobic grooves along the spiral direction, the length direction of the hydrophobic grooves is the same as the width direction of spiral baffles one / spiral baffles two, and the outer ends of the hydrophobic grooves extend to the outer ends of spiral baffles one / spiral baffles two. The hydrophobic grooves can guide the water flow to flow better, so that the water gathered on spiral baffles one and spiral baffles two can flow smoothly into the water distribution cavity along the hydrophobic grooves. When the water flow flows on the spiral plate, the hydrophobic grooves can play a role of constraint and guidance, avoiding the random flow of the water flow, ensuring that the water flow can efficiently enter the water distribution cavity from the spiral plate, and then participate in the stripping process in the filler cavity again.

[0012] Preferably, in the horizontal projection plane, the width of the second spiral baffle located inside the water distribution cavity is l, and the width of the water distribution cavity is x, then x / 5 < l < x / 3. The range of settings can ensure that the second spiral baffle can effectively guide the water flow into the water distribution cavity, and will not occupy too much space in the water distribution cavity, affecting the normal water distribution function of the water distribution cavity. If the width of the second spiral baffle located inside the water distribution cavity is too narrow, it may not be able to fully guide the water flow into the water distribution cavity, resulting in that part of the water flow cannot be effectively circulated; and if it is too wide, it will compress the effective space of the water distribution cavity, so that the water distribution is uneven, affecting the overall ammonia nitrogen stripping effect.

[0013] Preferably, the spiral number of the filler cavity is at least three turns. Sufficient spiral turns can significantly increase the flow path and residence time of the wastewater in the device, which means that the wastewater has more opportunities to fully contact with the gas flow, improves the efficiency of gas-liquid mass transfer, and more effectively transfers the ammonia nitrogen in the wastewater to the gas phase. When the wastewater flows in the spiral filler cavity, each turn provides a new gas-liquid contact interface, so that the removal of ammonia nitrogen is more sufficient. At the same time, the design of multiple turns can also buffer the fluctuations of gas flow and water flow to a certain extent, ensuring the stability of the device operation.

[0014] Preferably, the bottom of the tank body is provided with a discharge hole communicating with the filler cavity, and a sealing plate is mounted on the discharge hole. When the filler needs to be replaced, the sealing plate is opened, so that the filler in the filler cavity can be directly discharged by gravity. The sealing plate is fixedly connected with the edge of the discharge hole through a flange or a buckle structure, so as to ensure that the wastewater will not leak during operation.

[0015] Preferably, the bottom of the gas outlet is communicated with a gas collecting pipe coaxial with the tank body axis. A plurality of gas collecting holes are uniformly arranged on the gas collecting pipe. A flow guide channel is arranged in the gas collecting pipe. The top end of the flow guide channel has a plurality of outlets. The plurality of outlets are respectively communicated with gas collecting holes at different heights. The gas collecting pipe can more efficiently collect the gas carrying ammonia. Since the gas collecting pipe is coaxial with the tank body axis and the gas collecting holes are uniformly distributed, the ammonia-containing gas rising from different positions of the tank body can be more uniformly collected into the gas collecting pipe. The plurality of outlets at the top end of the flow guide channel are communicated with the gas collecting holes at different heights. This can reasonably guide and collect the gas according to the different heights and pressure conditions of the gas rising. When the gas enters the gas collecting pipe, it will be divided and guided through the flow guide channel, so that the gas can more orderly converge and be discharged from the gas outlet. Such design helps to improve the efficiency and stability of gas collection, ensures the smooth discharge of the gas phase in the whole ammonia nitrogen stripping process, and further improves the overall performance of the high ammonia nitrogen wastewater treatment device. At the same time, this design can also reduce the stagnation and turbulent flow of the gas in the tank body, reducing the adverse effects of the gas flow on the wastewater treatment effect.

[0016] A high ammonia nitrogen wastewater treatment method, comprising the following steps:

[0017] Step one: pretreatment, removing suspended solids, grease and heavy metals in wastewater;

[0018] Step two: pH value adjustment, increasing the pH value of wastewater to a high enough alkaline range to convert as much ammonium ion in water into free ammonia as possible;

[0019] Step three: using the high ammonia-nitrogen wastewater treatment device described above for stripping treatment;

[0020] Step four: introducing ammonia-containing waste gas into an acid washing tower to spray and absorb ammonia gas with dilute sulfuric acid or dilute hydrochloric acid.

[0021] The effect is that: through the pretreatment step, the suspended solids, grease and heavy metals in the wastewater can be effectively removed, preventing these impurities from interfering with the subsequent processing steps, reducing the risk of wear and blockage of the processing device, the pH value adjustment step is crucial, increasing the pH value of the wastewater to a high enough alkaline range can promote the conversion of a large number of ammonium ions in water into free ammonia, creating favorable conditions for subsequent stripping treatment, using the high ammonia-nitrogen wastewater treatment device of the application for stripping treatment, the wastewater is in full contact with the gas flow in the filler cavity, using the spiral structure and circulating flow design, greatly increasing the gas-liquid contact time and frequency, improving the ammonia-nitrogen stripping effect, effectively transferring ammonia-nitrogen in wastewater to the gas phase, finally introducing ammonia-containing waste gas into an acid washing tower to spray and absorb ammonia gas with dilute sulfuric acid or dilute hydrochloric acid, which can convert ammonia gas into ammonium salt for recycling, reducing ammonia gas pollution to the environment and achieving effective resource recovery. The entire treatment method is relatively simple to operate, has high processing efficiency, can significantly reduce the ammonia-nitrogen content in high ammonia-nitrogen wastewater, achieve good wastewater treatment effect, and reduce processing cost and environmental impact, with good economic and environmental benefits.

[0022] By adopting the above technical solutions, the application has the following advantages:

[0023] 1、The treated wastewater first enters the packing cavity of the treatment device uniformly through the water distributor. In the packing cavity, the wastewater is in full contact with the specially designed multi-faceted hollow sphere packing. This packing structure significantly increases the contact surface area of the water flow and the air, creating favorable conditions for the transfer of ammonia gas in the liquid phase to the gas phase. At the same time, the air blowing assembly continuously blows air into the packing cavity through multiple blowing heads installed on the spiral pipe. These air streams form strong convective contact with the wastewater in the packing cavity, effectively transferring dissolved ammonia gas from the liquid phase to the gas phase. Due to the spiral number of the spiral plate being not less than three turns and the uniform opening of multiple water filtering holes on the spiral plate, this structure allows the water flow to form multiple circulation flows between the packing cavity and the water distribution cavity, significantly prolonging the contact time of the gas-liquid two-phase and increasing the gas-liquid exchange frequency, thereby significantly improving the ammonia nitrogen stripping efficiency. When the ammonia gas-carrying air stream enters the inner cylinder, it enters the flow guide channel system through the evenly distributed gas collection holes on the gas collection pipe. This flow guide channel can distribute the air flow at different heights, effectively avoiding the problem of air flow differences caused by uneven blowing intensity of the air blowing assembly at different heights, ensuring the uniformity and stability of the air flow in the entire system. In the process of air flow pushing wastewater movement, some water droplets are inevitably carried along. Due to the double spiral plate design of the spiral baffle group (including spiral baffle one and spiral baffle two) and the overlapping area between the two plates, the water droplets will hit the surface of the spiral plate, while the gas can smoothly enter the gas collection hole through the gap between the spiral plates. The water droplets hitting the spiral plate will gradually converge under the action of surface tension and finally slide down the specially designed hydrophobic groove, returning to the water distribution cavity. These backflow water will enter the packing cavity again through the spiral plate and participate in the air blowing process again, repeating the cycle until the water flow finally settles at the bottom of the tank and is discharged from the water outlet. This design and structure fundamentally solve the problem of decreased treatment efficiency caused by the weakening of the air blowing effect on the top wastewater in traditional technology, significantly improving the ammonia nitrogen removal efficiency, significantly reducing the energy consumption and operating cost during the treatment process, and achieving the goal of efficient and energy-saving wastewater treatment.

[0024] 2、When replacing the multi-faceted hollow sphere, first open the sealing plate on the device. When the sealing plate is opened, the multi-faceted hollow spheres accumulated in the packing cavity will naturally slide down and be discharged due to their own gravity. If it is found that the multi-faceted hollow spheres are not discharged smoothly and there is a blockage, start the air blowing assembly to push the stagnant multi-faceted hollow spheres to move, thereby effectively unblocking the blocked parts in the packing cavity. This dual design of natural discharge combined with pneumatic assistance makes the entire packing replacement process very simple and efficient, greatly reducing the operation difficulty and maintenance cost. At the same time, this design also ensures that there are no old multi-faceted hollow spheres left in the packing cavity, creating good conditions for the subsequent installation of new packing. BRIEF DESCRIPTION OF DRAWINGS

[0025] Figure 1 is a front view of the present application.

[0026] Figure 2 is a schematic view of the structure inside the can body of the present application.

[0027] Figure 3 is a sectional view of the present application.

[0028] Figure 4 is a schematic view of Figure 3 is an enlarged schematic view of the structure at A in the middle.

[0029] Figure 5 is a schematic view of the structure of the spiral plate in the present application.

[0030] Figure 6 is a front view of the inner cylinder in the present application.

[0031] Figure 7 is a schematic view of the structure of the spiral plate group in the present application.

[0032] Reference Signs:

[0033] 1, can body; 11, water distributor; 12, air outlet; 13, water outlet; 14, sealing plate; 2, air blowing assembly; 21, spiral duct; 22, air blowing head; 23, main pipe; 3, outer cylinder; 4, inner cylinder; 5, spiral plate; 51, filler cavity; 52, water distribution cavity; 6, spiral baffle one; 7, spiral baffle two; 8, air collecting pipe; 81, flow guide channel. DETAILED DESCRIPTION

[0034] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below by reference to the drawings are exemplary and are intended to explain the present application, and should not be understood as limiting the present application.

[0035] As Figures 1-7As shown, a kind of high ammonia nitrogen wastewater treatment device, including tank body 1, water distributor 11, outer cylinder 3, inner cylinder 4, two spiral plates 5 and air blowing assembly 2, the top of tank body 1 is provided with water distributor 11 and gas outlet 12, bottom end is provided with water outlet 13, the bottom of gas outlet 12 is communicated with gas collecting pipe 8, gas collecting pipe 8, tank body 1, outer cylinder 3 and inner cylinder 4 are coaxially arranged between, outer cylinder 3 and inner cylinder 4 are separated by two spiral plates 5 and fill the cavity 51 and water distribution cavity 52, water distributor 11 is installed above outer cylinder 3, so that wastewater is evenly distributed to fill the cavity 51 in annular range, its water distribution range is equal to the range of fill the cavity 51 projection on horizontal plane, ensure that wastewater can effectively enter fill the cavity 51, outer cylinder 3, inner cylinder 4 and spiral plate 5 are all porous structure, this not only is favorable for the flow of gas-liquid, can also increase gas-liquid contact area, air blowing assembly 2 thus the outer cylinder 3 outside to fill the cavity 51 Blow gas, so that ammonia gas enters inner cylinder 4, then is discharged from gas outlet 12.

[0036] Multiple gas collecting holes are evenly provided on gas collecting pipe 8, and a flow guide channel is arranged in gas collecting pipe 8, the top end of the flow guide channel has multiple outlets, and the multiple outlets are respectively communicated with gas collecting holes at different heights, so that gas flows at different heights are respectively introduced into different gas collecting holes to complete shunting, to avoid that the gas flows blown by air blowing assembly 2 at different heights have great difference.

[0037] The filler is a polyhedral hollow sphere, which is a polyhedron composed of multiple geometric planes, the planes are connected by ribs to form a hollow and framework-like spherical body, so as to form a grid-like structure, the holes further increase the specific surface area and porosity of the polyhedral hollow sphere, and the hollow structure makes the porosity of the filler layer very high (usually more than 90%), which greatly reduces the resistance of gas flow through the filler layer and reduces energy consumption, and the material is polypropylene, the polyhedral hollow spheres are placed into fill the cavity 51 from the top end of fill the cavity 51, and the polyhedral hollow spheres roll downwards along the spiral plates 5 to fill the entire fill the cavity 51, after water distribution, the water flow flows through the polyhedral hollow spheres to increase the water flow surface area, so that the ammonia gas in the liquid phase can enter the gas phase better.

[0038] The spiral plate 5 has at least three spiral turns, and filter holes are arranged on the spiral plate 5 at equal intervals, the length direction of the filter holes is the same as the width direction of the spiral plate 5, when the water flow contacts the spiral plate 5 after separating from the hollow spherical balls, the water flow is prevented from flowing along the spiral direction of the spiral plate 5, and then the water flow enters the water distribution cavity 52 through the filter groove, and then enters the filler cavity 51 through the filter holes on the spiral plate 5, the bottom of the tank body 1 is provided with a discharge hole communicating with the filler cavity 51, and a sealing plate 14 is arranged on the discharge hole, when the hollow spherical balls need to be replaced, the sealing plate 14 is opened, so that the hollow spherical balls in the filler cavity 51 can be directly discharged by gravity, if the discharge is not smooth, the air blowing assembly 2 is started, so that the hollow spherical balls move and unblock, the sealing plate 14 is fixedly connected with the edge of the discharge hole through a flange or a buckle structure, so as to prevent wastewater from leaking during operation, the discharge hole can be long strip-shaped, and the width is designed to be 20-30 cm according to the size of the hollow spherical balls, and the sealing plate 14 is made of corrosion-resistant rubber material, and an annular groove is arranged on the surface to enhance the sealing performance.

[0039] The air blowing assembly 2 comprises a plurality of air blowing heads 22, a spiral pipe 21 and a blowing device (not shown in the figure), the spiral pipe 21 is wound outside the filler cavity 51, the air blowing heads 22 are arranged on the spiral pipe 21 at equal intervals, the pitch of the spiral pipe 21 is the same as the spiral pitch of the filler cavity 51, and the spiral pipe 21 is communicated with a main pipe 23, the main pipe 23 is fixedly arranged in the tank body 1, and the blowing device is communicated with the main pipe 23, so that air is conveyed into the main pipe 23, then into the spiral pipe 21 through the main pipe 23, and then blows air into the filler cavity 51 through the air blowing heads 22.

[0040] A spiral baffle group is arranged on the inner side of the inner cylinder 4, the spiral baffle group is composed of spiral baffles one 6 and spiral baffles two 7 with the same pitch, the spiral baffles one 6 and the spiral baffles two 7 are fixedly arranged in the tank body 1 through fixing rods, the number of the spiral baffles one 6 is at least one, and more can be arranged, preferably two, the spiral baffles one 6 are completely located in the inner cylinder 4, the spiral baffles one 6 and the spiral baffles two 7 are gradually inclined downward from the position close to the axis of the tank body 1 to the position far away from the axis of the tank body 1, and the outer end of the spiral baffles two 7 enters the water distribution cavity 52, the projections of the two spiral baffles one 6 on the plane where the axis of the tank body 1 is located have an overlapping area, the projections of the spiral baffles one 6 and the spiral baffles two 7 on the plane where the axis of the tank body 1 is located also have an overlapping area, a plurality of equal-interval water drainage grooves are arranged on the upper surfaces of the spiral baffles one 6 and the spiral baffles two 7 along the spiral direction of the spiral baffles one 6 and the spiral baffles two 7, the length direction of the water drainage grooves on the spiral baffles one 6 and the spiral baffles two 7 is the same as the width direction of the spiral baffles one 6 and the spiral baffles two 7, and the outer end of the water drainage grooves extends to the outer end of the spiral baffles one 6 and the spiral baffles two 7, and the water flow is prevented from moving along the spiral direction of the spiral plate 5 through the water drainage grooves.

[0041] In the horizontal projection plane, the width of the spiral baffle two 7 at the inside of the water distribution cavity 52 is l, and the width of the water distribution cavity 52 is x, then x / 5 < l < x / 3. By setting in this way, it can avoid that all the water droplets falling through the multi-surface hollow ball and the spiral plate 5 gather on the spiral plate 5, so as to be uniformly distributed in the water distribution cavity 52.

[0042] When the gas flow blows the wastewater, the gas blowing assembly 2 blows the gas, the gas flow passing through the filler cavity 51 carries water droplets. Since there is an overlapping area between the spiral plate 5, the water droplets hit the spiral baffle one 6 and the spiral baffle two 7. The gas enters the gas collection hole through the gap between the spiral baffle one 6 and the spiral baffle two 7. The water droplets on the spiral baffle one 6 and the spiral baffle two 7 gather and slide downward along the water-repellent groove to the outside, and finally enter the water distribution cavity 52. Then, the water droplets enter the filler cavity 51 through the spiral plate 5 again, and experience the gas blowing process again until the water flow falls to the bottom of the tank body 1.

[0043] Working principle: In the wastewater treatment process, the high ammonia-nitrogen wastewater is first pretreated to remove suspended solids, oil, heavy metals and other impurities. Then, the pH value of the wastewater is adjusted to a high enough alkaline range to convert the ammonium ion in the water into free ammonia as much as possible. Then, the treated wastewater is introduced into the filler cavity 51 of the treatment device through the water distributor 11. In the filler cavity 51, the wastewater is in full contact with the multi-surface hollow ball filler, which increases the water flow surface area and is beneficial to the ammonia gas in the liquid phase to enter the gas phase. The gas blowing assembly 2 blows gas into the filler cavity 51 through the gas blowing head 22 on the spiral pipe 21. The gas flow is in full contact with the wastewater in the filler cavity 51, and the ammonia gas is transferred from the liquid phase to the gas phase. Since the spiral plate 5 has at least three spiral turns, and the spiral plate 5 is provided with water filtering holes, the water flow circulates multiple times between the filler cavity 51 and the water distribution cavity 52, which increases the gas-liquid contact time and frequency, and improves the ammonia-nitrogen stripping effect. The gas flow carrying ammonia gas enters the inner cylinder 4, and then enters the flow guide flow channel through the gas collection hole of the gas collection pipe 8. The flow guide flow channel separately divides the gas flow at different heights to avoid large differences in the gas flow blown by the gas blowing assembly 2 at different heights, ensuring the uniformity and stability of the gas flow. In the process of the gas flow blowing the wastewater, the gas flow carries water droplets. Since there is an overlapping area between the spiral baffle one 6 and the spiral baffle two 7 of the spiral baffle group, the water droplets hit the spiral plate 5. The gas enters the gas collection hole through the gap between the spiral plate 5. The water droplets on the spiral plate 5 gather and slide downward along the water-repellent groove, enter the water distribution cavity 52, and then enter the filler cavity 51 through the spiral plate 5 again to experience the gas blowing process again until the water flow falls to the bottom of the tank body 1 and is discharged from the water outlet 13. The problem of poor treatment effect caused by the large decrease in the stripping effect of the gas flow on the top wastewater in the related art is solved, the ammonia-nitrogen removal efficiency is improved, and the treatment cost and energy consumption are reduced.

[0044] A high ammonia-nitrogen wastewater treatment method, characterized by comprising the following steps:

[0045] Step one: pretreatment, remove suspended solids, grease, heavy metals in wastewater;

[0046] Step two: pH adjustment, increase the pH of the wastewater to a high enough alkaline range, so that the ammonium ion in the water is converted into free ammonia as much as possible;

[0047] Step three: use high ammonia nitrogen wastewater treatment device for stripping treatment;

[0048] Step four: introduce ammonia-containing waste gas into the acid washing tower, and spray absorb ammonia gas with dilute sulfuric acid or dilute hydrochloric acid.

[0049] Among them, the pretreatment step separates suspended solids and grease by physical or chemical methods to avoid interference of impurities in the subsequent stripping process; the pH adjustment step uses alkaline reagent to raise the pH of the wastewater to above 10.5, to promote the conversion of ammonium ions into free ammonia molecules; the stripping treatment step uses a device with a spiral water distribution chamber 52 and a filler chamber 51, to enhance the gas-liquid contact efficiency through spiral airflow distribution; the acid washing step uses an acid solution to react with ammonia gas to generate ammonium salt, achieving waste gas purification.

[0050] Specifically, the pretreatment stage removes suspended solids and grease by precipitation, filtration or flotation process to prevent filler blockage and reduce mass transfer efficiency. In the pH adjustment stage, sodium hydroxide or lime milk is added to stabilize the pH of the wastewater in the range of 10.5-11.5, so that the conversion rate of ammonium ions exceeds 90%. In the stripping treatment stage, wastewater forms a uniform liquid film in the spiral water distribution chamber 52, the rotating airflow generated by the spiral pipe 21 forms countercurrent contact with the liquid film on the surface of the filler, the spiral baffle group guides the water circulation to prolong the residence time, and the porous structure promotes gas-liquid mass transfer. In the acid washing stage, ammonia-containing waste gas enters the acid washing tower from the top of the stripping tower, and the dilute sulfuric acid or hydrochloric acid spray liquid reacts with ammonia gas to generate ammonium sulfate or ammonium chloride solution, achieving harmless treatment of waste gas. This method optimizes the structure of the stripping device and the process steps, reduces the height of the filler while improving the ammonia nitrogen removal efficiency, and effectively avoids secondary pollution through acid washing treatment.

[0051] In the pretreatment stage, the wastewater is first filtered through a screen to remove large particles of suspended matter, then enters the air flotation tank, and through the release of micro-bubbles by pressurized dissolved air water, the grease is adsorbed and separated by floating, and finally, sodium sulfide solution is added to make heavy metal ions into sulfide precipitate; in the pH value adjustment stage, the pretreated wastewater is introduced into the neutralization tank, sodium hydroxide solution is added to stabilize the pH value in the range of 10.8-11.2, and the stirring reaction is carried out for 30 minutes to fully convert the ammonium ion into free ammonia; in the stripping treatment stage, the wastewater is pumped into the water distributor 11 at the top of the tank 1, uniformly sprayed into the filler cavity 51, and the air driven by the air blowing device forms a spiral upward airflow through the air distribution holes of the spiral pipe 21, the wastewater and the airflow are countercurrently contacted on the surface of the filler, the free ammonia enters the inner cylinder 4 with the airflow, and after being guided by the spiral baffle group, it enters the water distribution cavity 52 for circulation; the ammonia-containing waste gas enters the pickling tower through the air outlet pipe, the tower is provided with a nozzle with a pore size of 2mm, and a dilute sulfuric acid solution with a concentration of 15% is used for stepwise spraying, the ammonia gas in the waste gas reacts with sulfuric acid to generate ammonium sulfate solution, and the finally purified gas is discharged up to the standard.

[0052] Through the above technical solution, the application effectively reduces the interference of impurities on the stripping process through multi-stage pretreatment, and the precise control of alkaline conditions ensures the maximum conversion efficiency of ammonia molecules; the dynamic contact mode of spiral airflow and filler prolongs the gas-liquid mass transfer time and improves the ammonia nitrogen removal rate; the stepwise spraying design in the acid washing tower strengthens the gas-liquid mixing and avoids ammonia gas escape, which reduces the equipment operation energy consumption while ensuring the treatment efficiency, solves the problem of top treatment efficiency decay caused by ammonia partial pressure accumulation in the traditional stripping tower, and realizes the stable standard treatment of high ammonia nitrogen wastewater.

[0053] Although the embodiments of the application have been shown and described above, it should be understood that the above embodiments are exemplary and should not be construed as limiting the application, and those skilled in the art can make changes, modifications, replacements and variations to the above embodiments within the scope of the application.

Claims

1. A high-ammonia-nitrogen wastewater treatment device, comprising a tank body, a water distributor and a gas outlet being arranged at the top of the tank body, a water outlet being arranged at the bottom end of the tank body, and a filler and a gas blowing assembly being arranged in the tank body, characterized in that, The outer cylinder and the inner cylinder are coaxially arranged in the tank body, two spiral plates are arranged between the outer cylinder and the inner cylinder, the two spiral plates separate the space between the outer cylinder and the inner cylinder into a filler cavity and a water distribution cavity, the water distribution range of the water distributor is equal to the range of the filler cavity projected on the horizontal plane, the outer cylinder, the inner cylinder and the spiral plate are all porous structures, the air blowing assembly comprises a spiral pipe arranged outside the outer cylinder and a blowing device, the spiral pitch of the spiral pipe is the same as that of the spiral plate, and air blowing heads for blowing air into the filler cavity are arranged at equal intervals on the spiral pipe, a spiral baffle group is arranged on the inner side of the inner cylinder, the spiral baffle group gradually inclines downward from a position close to the axis of the tank body to a position away from the axis of the tank body, the spiral baffle group is composed of spiral baffles one and spiral baffles two with the same spiral pitch, the number of the spiral baffles one is at least one, and there are passages for the gas to pass through between the spiral baffles one and the spiral baffles two, the spiral baffles one are completely located in the inner cylinder, and the outer ends of the spiral baffles two enter the water distribution cavity, so that the water flow blown by the air flow enters the water distribution cavity along the spiral baffles; the water filtering holes are arranged on the spiral plate along the spiral direction of the spiral plate, and the length direction of the water filtering holes is the same as the width direction of the spiral plate; The upper surfaces of the spiral baffles one and the spiral baffles two are all provided with a plurality of equal-interval water draining grooves along the spiral direction of the spiral baffles one and the spiral baffles two, the length direction of the water draining grooves is the same as the width direction of the spiral baffles one / the spiral baffles two, and the outer ends of the water draining grooves extend to the outer ends of the spiral baffles one / the spiral baffles two; the number of the spiral turns of the filler cavity is at least three turns.

2. The high-ammonia-nitrogen wastewater treatment apparatus according to claim 1, wherein The spiral baffles one and the spiral baffles two overlap in the projection plane of the tank body axis plane.

3. The high-ammonia-nitrogen wastewater treatment apparatus according to claim 2, characterized by In the horizontal projection plane, the width of the spiral baffles two at the inner position of the water distribution cavity is l, and the width of the water distribution cavity is x, so x / 5 < l < x / 3.

4. The high-ammonia-nitrogen wastewater treatment apparatus according to claim 1, wherein A discharge hole communicating with the filler cavity is arranged in the bottom of the tank body, and a sealing plate is arranged on the discharge hole.

5. The high-ammonia-nitrogen wastewater treatment apparatus according to claim 1, wherein A gas collecting pipe is communicated with the bottom of the air outlet, the gas collecting pipe is coaxial with the tank body axis, a plurality of gas collecting holes are uniformly arranged on the gas collecting pipe, and a flow guide channel is arranged in the gas collecting pipe, the top end of the flow guide channel is provided with a plurality of outlets, and the plurality of outlets are respectively communicated with the gas collecting holes at different heights.

6. A method for treating high-ammonia-nitrogen wastewater, characterized by, The method comprises the following steps: Step one: pretreatment, removing suspended solids, grease and heavy metals in the wastewater; Step two: pH value adjustment, increasing the pH value of the wastewater to above 10.5 to convert the ammonium ion in the water into free ammonia; Step three: using the high ammonia-nitrogen wastewater treatment device according to any one of claims 1-5 for air stripping treatment; Step four: introducing the ammonia-containing waste gas into an acid washing tower to spray and absorb ammonia gas with dilute sulfuric acid or dilute hydrochloric acid.

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