Device for treating deeper bottom mud in situ by utilizing gas stripping

Abstract

The utility model discloses a device for treating deeper bottom mud in situ by utilizing gas stripping, and relates to the technical field of water environment pollution treatment. The device comprises a gas stripping lifting pipe and a water body moving device, a stirring machine is installed on the top face of the gas stripping lifting pipe in a sliding mode, a plurality of impellers are arranged at the output end of the stirring machine, a bottom mud backflow pipe is fixedly arranged on the outer surface of the gas stripping lifting pipe in a sleeved mode, and the bottom mud backflow pipe is installed on one side of the water body moving device in a sliding mode. A plurality of gas stripping mud pipes are arranged on the outer surface of the top of the gas stripping lifting pipe, deep bottom mud is subjected to gas stripping lifting, then reoxygenation and chemical adding are conducted, then the deep bottom mud returns to a bottom mud layer, a slow-release carbon source, a phosphorus removal chemical and nitrate are brought to the bottom mud layer with insufficient oxygen, and pollutants in the bottom mud are removed in situ. The loosening of the bottom mud layer can enhance the mass transfer rate in the bottom mud, and an anoxic environment is formed in the bottom mud layer. According to the in-situ bottom mud treatment device, in-situ bottom mud treatment is realized in a simple manner.

Description

Technical Field

[0001] This utility model relates to the field of water environment pollution control technology, specifically a device for in-situ treatment of deep bottom sediment using airlift. Background Technology

[0002] This year, the national surface water environment has improved significantly, with the proportion of Class II water bodies among the key national monitoring water bodies increasing from 29.1% in 2002 to 89.4% in 2023. However, the 2023 ecological and environmental bulletin shows that the proportion of important lakes and reservoirs in eutrophication remains high at 27%. As water sources, lakes and reservoirs urgently need to address their eutrophication status.

[0003] The main pollutants causing eutrophication in water bodies are nitrogen and phosphorus, which mainly originate from external and internal pollution sources. With increasingly stringent environmental protection requirements in my country, most external pollution sources in important water bodies have been prevented from entering through rainwater and sewage separation and initial rainwater interception. Therefore, internal pollution has become a significant source of pollution for many water bodies, with bottom sediment being a major contributor. The nitrogen and phosphorus concentrations in bottom sediment can reach as high as 15,000 mg / kg and 1,000 mg / kg, respectively. Current methods for treating bottom sediment primarily involve dredging or adding sediment conditioners. However, dredging is costly, and the removed sludge still requires dewatering and proper disposal. While sediment conditioners can inhibit the release of pollutants from bottom sediment into the water, they only work on the surface. The large amounts of pollutants contained in the sediment below the surface remain a potential source of water pollution. To address these issues, the inventors propose a device for in-situ treatment of deeper bottom sediment using airlift. Utility Model Content

[0004] The main methods for treating bottom sediment are dredging or adding sediment conditioners, but dredging is costly and the removed sediment still needs to be dehydrated and properly disposed of. The purpose of this invention is to provide a device for in-situ treatment of deeper bottom sediment using air lifting.

[0005] To solve the above-mentioned technical problems, this utility model adopts the following technical solution: a device for in-situ treatment of deep bottom sediment using air lift, comprising an air lift pipe and a water-based mobile device. A mixer is slidably mounted on the top surface of the air lift pipe, and the output end of the mixer is provided with multiple impellers. A bottom sediment return pipe is fixedly sleeved on the outer surface of the air lift pipe, and the bottom sediment return pipe is slidably mounted on one side of the water-based mobile device. Multiple air lift sludge extraction pipes are provided on the top outer surface of the air lift pipe, and valves are installed on the outer surface of the multiple air lift sludge extraction pipes. A mud discharge pipe is connected to the outer surface of one of the air lift sludge extraction pipes. The mud discharge pipe is a flexible pipe. A cascading mixing and reoxygenation zone is provided on the outer surface of the bottom sediment return pipe. The end of the mud discharge pipe away from the air lift sludge extraction pipe is... Connected within the cascading mixing and reoxygenation zone, the top surface of the water-moving equipment is fixedly equipped with a chemical tank. A pump body is located on one side of the chemical tank, and a chemical extraction pipe is connected between the chemical tank and the pump body. A chemical dosing pipe is fixedly located at one end of the pump body and is fixedly connected to the mud outflow pipe. After the water-moving equipment is moved to the designated position, the air lift pipe, mixer, and bottom mud return pipe are driven downwards to the depth of the bottom mud. Then, the mixer is turned on, and the mixing rod slides up and down inside the air lift pipe, thereby loosening the bottom mud with the impeller. At the same time, the water on the top of the bottom mud mixes with the bottom mud, thereby increasing the moisture content of the bottom mud to meet the air lift requirements. When the moisture content of the bottom mud in the target water body is too low, water is manually added from the top of the air lift pipe during the mixing and air lift process to increase the moisture content of the mixed bottom mud. After the mixer moves up and down and mixes for 15-60 minutes, air lifting is performed to lift the mud-liquid mixture until it can no longer be lifted or it can run continuously for more than 60 minutes (when the bottom mud is relatively loose, the bottom mud in the air lifting pipe and the bottom mud return pipe will flow fully). Then the blower is turned on, so that air is delivered from the air delivery pipe to the air lifting pipe, and the bottom mud can flow from the air lifting pipe to the mud outlet pipe. At the same time, the pump is turned on to extract the agent in the agent tank and deliver it to the mud outlet pipe through the dosing pipe. Then it flows with the bottom mud into the cascade mixing and reoxygenation zone.

[0006] The spiral-shaped downward-flowing channel features several cascades with a height (H) of 5-25 cm. The channel extends a distance (L) 15-30 cm beyond each cascade to ensure adequate reoxygenation during the cascading process. After reoxygenation in the cascading mixing and reoxygenation zone, the sludge, mixed with chemicals by the water flow, falls underwater through the outlet pipe at the end of the cascading mixing and reoxygenation zone. Finally, the chemically mixed and reoxygenated sludge-chemical mixture settles to the bottom sediment surface, while excess water in the mixture is slowly released into the water phase. The sludge-chemical mixture undergoes thorough reoxygenation during the cascading and flowing process, and nitrifying bacteria carried in the water simultaneously perform nitrification, forming nitrates. Due to the high pollutant concentration and rapid oxygen consumption rate in the bottom sediment layer, the sludge-chemical mixture that settles back to the bottom quickly reaches anoxic or anaerobic conditions, facilitating the denitrification process of nitrates oxidized by reoxygenation. Combined with the slow-release carbon source carried on the mixture, denitrification is achieved. The entire device achieves increased water content by stirring deep-water sediment, mixing it with chemicals via air stripping, and completing the nitrification process while simultaneously reoxygenating. The mixture is then returned to the sediment surface, contacting the existing sediment and carrying the necessary denitrification carbon sources, nitrates, phosphorus removal chemicals, and oxygen. This provides the necessary environmental and material conditions for removing sediment contaminants underwater. The device's residence time and operating time at each location can be determined based on the actual conditions of the sediment in the water body.

[0007] Preferably, the cascading mixing and reoxygenation zone is a spiral downward-flowing channel with several cascading points in the middle. The top of the cascading mixing and reoxygenation zone is provided with a starting point sealing end, which is fixedly connected to the mud slurry outlet pipe. The bottom surface of the cascading mixing and reoxygenation zone is provided with an end outlet pipe.

[0008] Preferably, the top surface of the water-based mobile equipment is provided with a blower, one end of which is fixedly provided with an air delivery pipe, and the other end of which is fixedly provided inside an air lifting pipe.

[0009] Compared with the prior art, the beneficial effects of this utility model are as follows:

[0010] 1. The bottom sediment is fully reoxygenated through airlift and drop processes. While the nitrification process is underway, the bottom sediment with relatively high dissolved oxygen is sent back to the bottom of the water. The slow-release denitrification and phosphorus removal agents carried at the same time are used to treat the bottom sediment in situ at the bottom of the water.

[0011] 2. By stirring, the bottom sediment is cleared, the dissolved oxygen environment of the deep bottom sediment is improved, and diverse environmental conditions are provided, which is conducive to the degradation of pollutants in the bottom sediment. Attached Figure Description

[0012] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a cross-sectional structural diagram of a device for in-situ treatment of deep mud using airlift according to this utility model.

[0014] Figure 2 This is a top view of the cascading water mixing and reoxygenation zone of this utility model;

[0015] Figure 3 This is a detailed structural diagram of the cascading point in the mixed oxygenation zone of this utility model.

[0016] In the diagram: 1. Air lift pipe; 2. Mixer; 3. Bottom sediment return pipe; 4. Impeller; 5. Air lift sludge pipe; 6. Sludge discharge pipe; 7. Cascade mixing and reoxygenation zone; 7-1. Flow channel; 7-2. Cascade point; 7-3. Starting point sealing end; 7-4. End outlet pipe; 8. Blower; 9. Air delivery pipe; 10. Chemical tank; 11. Chemical dosing pipe; 12. Water body moving equipment; 13. Sludge-chemical mixture. Detailed Implementation

[0017] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0018] Example: Figure 1-3As shown, this utility model provides a device for in-situ treatment of deep bottom sediment using air lift, including an air lift pipe 1 and a water-based mobile device 12. A mixer 2 is slidably mounted on the top surface of the air lift pipe 1, and the output end of the mixer 2 is equipped with multiple impellers 4. A bottom sediment return pipe 3 is fixedly sleeved on the outer surface of the air lift pipe 1 and slidably mounted on one side of the water-based mobile device 12. The air lift pipe 1, mixer 2, and bottom sediment return pipe 3 are connected together and slide up and down on one side of the water-based mobile device 12. The mixer 2 can slide up and down independently relative to the air lift pipe 1, and the up and down movement of the two parts is independent. Multiple air lift sludge extraction pipes 5 are provided on the top outer surface of the air lift pipe 1, and valves are installed on the outer surface of the multiple air lift sludge extraction pipes 5. One of the air lift sludge extraction pipes 5 is connected to a mud slurry outlet pipe 6 on its outer surface. The mud slurry outlet pipe 6 is a flexible pipe. A cascading mixing and reoxygenation zone 7 is provided on the outer surface of the bottom sediment return pipe 3, and the mud slurry outlet... One end of pipe 6 away from the air-lift sludge pipe 5 is connected to the cascading mixing and reoxygenation zone 7. A chemical tank 10 is fixedly installed on the top surface of the water body mobile device 12. A pump body is installed on one side of the chemical tank 10, and a chemical extraction pipe is provided between the chemical tank 10 and the pump body. A chemical dosing pipe 11 is fixedly installed at one end of the pump body. The chemical dosing pipe 11 is fixedly connected to the sludge outlet pipe 6. (The distance between the uppermost gas outlet pipe 5 and the top of the gas lift pipe 1 is 20-50cm). According to the depth of the bottom sediment, the sludge outlet pipe 6 is connected to the air-lift sludge pipe 5 at an appropriate height. Only the valve of the air-lift sludge pipe 5 connected to the sludge outlet pipe 6 is opened, and the other valves are closed. The water body mobile device 12 can be a boat hull, a separate floating body, etc., with a certain working area, including a blower 8, a chemical tank 10, and an operating area. The specific area is set according to the depth and pollution level of the bottom sediment. The chemical tank 10 can be single or multiple, and all are transported to the dosing point through pumps and pipelines. Depending on the pollution level of the bottom sediment, denitrification slow-release carbon sources, phosphorus removal agents, specific microorganisms, or other agents can be added to the sediment. After the water body mobile device 12 is moved to the designated position, the air lift pipe 1, mixer 2, and sediment return pipe 3 are pushed down into the sediment. Then, the mixer 2 is turned on, and the mixing rod 2 slides up and down inside the air lift pipe 1, thereby loosening the sediment by the impeller 4. At the same time, the water on the top of the sediment mixes with the sediment, thereby increasing the moisture content of the sediment to meet the air lift requirements. When the moisture content of the sediment in the target water body is too low, water is manually added from the top of the air lift pipe 1 during the mixing and air lift process to increase the moisture content of the mixed sediment.After the mixer 2 moves up and down and mixes for 15-60 minutes, air lifting is performed to lift the mud-liquid mixture until it can no longer be lifted or can run continuously for more than 60 minutes (when the bottom mud is relatively loose, the bottom mud in the air lifting pipe 1 and the bottom mud return pipe 3 flows fully). Then the blower 8 is turned on, so that air is delivered from the air delivery pipe 9 to the air lifting pipe 1, and the bottom mud can flow from the air lifting pipe 5 to the mud outlet pipe 6. At the same time, the pump is turned on to extract the agent in the agent tank 10 and deliver it to the mud outlet pipe 6 through the dosing pipe 11. Then it flows with the bottom mud to the cascade mixing and reoxygenation zone 7.

[0019] The cascading mixing and reoxygenation zone 7 is a spiral downward-flowing channel 7-1 with several cascading points 7-2 in the middle. The top of the cascading mixing and reoxygenation zone 7 is provided with a starting point sealing end 7-3, which is fixedly connected to the mud slurry outlet pipe 6. The bottom surface of the cascading mixing and reoxygenation zone 7 is provided with an end outlet pipe 7-4.

[0020] By adopting the above technical solution, both the sediment input point and the chemical dosing point are located at the end of the cascade mixing and reoxygenation zone 7. The number of layers, length, flow velocity, and residence time of the spiral downward flow channel 7-1 are determined according to the properties of the sediment. The spiral downward flow channel 7-1 has several cascade points 7-2 in the middle, with a cascade height H of 5-25 cm. After the cascade points 7-2, the channel extends a certain distance L inward, with a length L of 15-30 cm, to ensure sufficient reoxygenation during the cascade process. After reoxygenation and chemical mixing in the cascade mixing and reoxygenation zone 7, the sludge falls underwater through the outlet pipe 7-4 at the end of the cascade mixing and reoxygenation zone 7. Finally, the sludge-chemical mixture 13, after being mixed with chemicals and reoxygenated, settles to the surface of the sediment, and excess water in the mixture is slowly released into the water phase. The sludge mixture is fully reoxygenated during the cascade and flow process, and the nitrifying bacteria carried in the water can simultaneously carry out nitrification to form nitrates. Due to the high concentration of pollutants and rapid oxygen consumption in the bottom sediment layer, the sludge-chemical mixture that settles back to the bottom quickly reaches anoxic or anaerobic conditions, which is conducive to the denitrification process of nitrates through reoxygenation and oxidation. Combined with the carried slow-release carbon source, nitrogen removal is achieved. The entire device achieves agitation of the deeper bottom sediment to increase the water content, airlifts and mixes the chemicals, completing the nitrification process simultaneously with reoxygenation, and then returns it to the bottom sediment surface to contact the existing sediment, carrying the necessary denitrification carbon source, nitrates, phosphorus removal chemicals, and oxygen. This provides the environmental and material conditions for removing pollutants from the bottom sediment underwater. The device's residence time and operating time at each point can be determined according to the actual conditions of the bottom sediment in the water body.

[0021] The top surface of the water-body mobile device 12 is provided with a blower 8. One end of the blower 8 is fixedly provided with an air delivery pipe 9, and the other end of the air delivery pipe 9 is fixedly provided inside the air lifting pipe 1.

[0022] By adopting the above technical solution, the blower 8 is turned on, so that air is transported from the air delivery pipe 9 to the air lifting pipe 1, and then the bottom mud can flow from the air lifting mud pipe 5 to the mud discharge pipe 6.

[0023] Working principle: After the water body moving device 12 is moved to the designated position, the air lift pipe 1, mixer 2 and bottom sediment return pipe 3 are pushed down into the bottom sediment as a whole. Then the mixer 2 is turned on and the mixing rod 2 slides up and down in the air lift pipe 1, thereby loosening the bottom sediment by the impeller 4. At the same time, the water on the top of the bottom sediment mixes with the bottom sediment, thereby increasing the moisture content of the bottom sediment to meet the air lift requirements. When the moisture content of the bottom sediment in the target water body is too low, water is manually added from the top of the air lift pipe 1 during the mixing and air lift process to increase the moisture content of the mixed bottom sediment. After the mixer 2 moves up and down and mixes for 15-60 minutes, air lifting is performed to lift the mud-liquid mixture until it can no longer lift the mud-liquid mixture or can run continuously for more than 60 minutes (when the bottom mud is relatively loose, the bottom mud in the air lifting pipe 1 and the bottom mud return pipe 3 flows fully). Then the blower 8 is turned on, so that air is delivered from the air delivery pipe 9 to the air lifting pipe 1, and the bottom mud can flow from the air lifting pipe 5 to the mud-liquid outlet pipe 6. At the same time, the pump is turned on to extract the agent in the agent tank 10 and deliver it to the mud-liquid outlet pipe 6 through the dosing pipe 11. Then it flows with the bottom mud to the cascade mixing and reoxygenation zone 7.

[0024] A spiral-shaped downward-flowing channel 7-1 has several drop points 7-2 in the middle, with a drop height H of 5-25cm. After the drop points 7-2, the channel extends a certain distance L inward, with a length L of 15-30cm, to ensure sufficient reoxygenation during the drop process. After reoxygenation in the drop mixing and reoxygenation zone 7 and mixing with the chemicals in the water flow, the sludge falls into the water through the outlet pipe 7-4 at the end of the drop mixing and reoxygenation zone 7. Finally, the sludge-chemical mixture 13, which has been mixed with chemicals and reoxygenated, settles to the bottom sediment surface. Excess water in the sludge-chemical mixture is slowly released into the water phase. The sludge mixture is fully reoxygenated during the drop and flow process, and the nitrifying bacteria carried in the water can simultaneously carry out the nitrification process to form nitrates. Due to the high concentration of pollutants and the fast oxygen consumption rate in the bottom sediment layer, the sludge-chemical mixture that has settled back to the bottom quickly reaches an anoxic or anaerobic state, which is conducive to the denitrification process of nitrates oxidized by reoxygenation, and denitrification is achieved in combination with the slow-release carbon source carried on board. The entire device achieves increased water content by stirring deep-water sediment, mixing it with chemicals via air stripping, and completing the nitrification process while simultaneously reoxygenating. The mixture is then returned to the sediment surface, contacting the existing sediment and carrying the necessary denitrification carbon sources, nitrates, phosphorus removal chemicals, and oxygen. This provides the necessary environmental and material conditions for removing sediment contaminants underwater. The device's residence time and operating time at each location can be determined based on the actual conditions of the sediment in the water body.

[0025] All standard parts used in this invention can be purchased from the market, and irregular parts can be customized according to the description and drawings. The specific connection methods of each part adopt conventional methods such as bolts, rivets, and welding that are mature in the prior art. The machinery, parts and equipment adopt conventional models in the prior art, and the circuit connection adopts conventional connection methods in the prior art, which will not be described in detail here.

[0026] Obviously, those skilled in the art can make various modifications and variations to this utility model without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this utility model and their equivalents, this utility model also intends to include these modifications and variations.

Claims

1. An apparatus for in situ treatment of deeper bottom sediments with gas stripping, comprising a gas stripping riser (1) and a water body moving device (12), characterised in that: The top surface of the gas stripping riser (1) is slidingly installed with a stirrer (2), the output end of the stirrer (2) is provided with a plurality of impellers (4), the outer surface of the gas stripping riser (1) is fixedly sleeved with a bottom mud return pipe (3), the bottom mud return pipe (3) is slidingly installed on one side of a water body moving device (12), the gas stripping riser (1), the stirrer (2) and the bottom mud return pipe (3) are connected together and slide up and down on one side of the water body moving device (12), the stirrer (2) can independently slide up and down relative to the gas stripping riser (1), the top outer surface of the gas stripping riser (1) is provided with a plurality of gas mud pipes (5), the outer surface of the plurality of gas mud pipes (5) is installed with a valve, the outer surface of one of the gas mud pipes (5) is connected with a mud liquid outflow pipe (6), the outer surface of the bottom mud return pipe (3) is provided with a waterfall mixed reoxygenation zone (7), the end of the mud liquid outflow pipe (6) away from the gas mud pipe (5) is connected in the waterfall mixed reoxygenation zone (7), the top surface of the water body moving device (12) is fixedly provided with a medicament box (10), one side of the medicament box (10) is provided with a pump body, and an agent suction pipe is arranged between the medicament box (10) and the pump body, one end of the pump body is fixedly provided with a dosing pipe (11), and the dosing pipe (11) is fixedly connected in the mud liquid outflow pipe (6).

2. A device for in situ treatment of deeper bottom sediments using air stripping as claimed in claim 1, characterized in that, The waterfall mixed reoxygenation zone (7) is a spiral downward flow channel (7-1) with a plurality of waterfall points (7-2) arranged in the middle.

3. A device for in situ treatment of deeper bottom sediments by gas stripping according to claim 1, characterized in that, The top end of the waterfall mixed reoxygenation zone (7) is provided with a starting point sealing end (7-3), the starting point sealing end (7-3) is fixedly connected with the mud liquid outflow pipe (6), and the bottom surface of the waterfall mixed reoxygenation zone (7) is provided with an end water outlet pipe (7-4).

4. A device for in situ treatment of deeper bottom sediments by gas stripping according to claim 1, characterised in that, The top surface of the water body moving device (12) is provided with a blowing device (8), one end of the blowing device (8) is fixedly provided with an air conveying pipe (9), the other end of the air conveying pipe (9) is fixedly provided in the gas stripping riser (1), and the air conveying pipe (9) and the gas stripping riser (1) are mutually penetrated.

5. A device for in situ treatment of deeper bottom sediments by gas stripping according to claim 1, characterised in that, The mud liquid outflow pipe (6) is a soft pipe.

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