An electric guided drainage system and method for in-situ separation and recovery of phosphorus from river and lake sediments

Abstract

This invention provides an electrically driven pumping system and method for in-situ separation and recovery of phosphorus from river and lake sediments. The device includes an electrically driven pumping unit, a temperature-controlled heating rod, a water-insulating blanket, a sediment water-phosphorus recovery blanket, and a power supply module. The electrically driven pumping unit is a cylindrical device integrally molded from acid- and alkali-resistant conductive plastic, with a conical bottom, a porous surface covered with a permeable cloth, and a miniature submersible pump installed inside. The water-insulating blanket is located around the outer ring of the sediment water-phosphorus recovery blanket and is laid at the river / lake sediment-water interface. The electrically driven pumping unit and the temperature-controlled heating rod are installed below the sediment water-phosphorus recovery blanket. The miniature submersible pump is used to pump pore water from phosphorus-rich sediment to the sediment water-phosphorus recovery blanket. The power supply module provides power to the electrically driven pumping unit, the miniature submersible pump, and the temperature-controlled heating rod. This invention is unaffected by aquatic environment and climate change, is highly efficient and environmentally friendly, and is universally applicable to the reduction, remediation, and resource recovery of phosphorus in river and lake sediments. The device can be laid over large areas and is highly operable on-site.

Description

Technical Field

[0001] This invention relates to the field of environmental governance, specifically to an electric discharge system and method for in-situ separation and recovery of phosphorus from river and lake sediments. Background Technology

[0002] Large amounts of nitrogen and phosphorus discharged from production and daily life enter natural water bodies via runoff, easily causing eutrophication of rivers and lakes and accumulating in bottom sediments. When factors such as dissolved oxygen, water temperature, and pH in the overlying water change, phosphorus in the bottom sediments will be released again, becoming an endogenous source of water pollution. On the other hand, phosphorus is also an indispensable, irreplaceable, and non-renewable strategic resource. Therefore, the reduction, remediation, and recycling of phosphorus in lake and reservoir bottom sediments are of great significance, both from the perspective of controlling eutrophication and from the perspective of resource utilization.

[0003] Currently, the remediation of high-phosphorus loads in sediment mainly includes ex-situ control and in-situ control technologies. Ex-situ control involves dredging lake and reservoir sediments from the water body and then treating or recovering phosphorus from the sediment through methods such as leaching and electrostatic remediation. However, ex-situ control technologies involve large engineering projects, significant water disturbance, and large sediment accumulation, making widespread application difficult. In-situ control technologies involve adding a layer of environmentally friendly and pollution-free covering material to the lake or reservoir water body, or spraying chemical agents, to inhibit the release of phosphorus from the sediment into the water body through physical, chemical, and biological processes. However, this technology has not achieved the reduction, remediation, and resource recovery of high-phosphorus loads in sediment.

[0004] The aforementioned problems were largely addressed in the inventor's previously filed patent, "A Device and Method for Accelerating the Release and Recycling of Endogenous Phosphorus in Eutrophic Water" (Authorization No.: ZL202210554452.9). However, during application, it was found that for low-oxygen water bodies, the release of phosphorus from the sediment into the sediment pore water and its overlying water is slow. Furthermore, the contact between the environmentally friendly phosphorus adsorption material and the overlying water is insufficient, and the slow phosphorus adsorption and recycling further affects the endogenous release of phosphorus from the sediment. Therefore, the existing devices and methods are not very effective and lack broad applicability for accelerating the release and recycling of endogenous phosphorus in low-oxygen water bodies. Summary of the Invention

[0005] To address the problem of slow release and recycling of endogenous phosphorus from low dissolved oxygen water into the pore water of sediment and its overlying water, this invention proposes an electric discharge system and method for in-situ separation and recovery of phosphorus from river and lake sediments.

[0006] The technical solution adopted in the present invention is:

[0007] An electric conveying system for in-situ separation and recovery of phosphorus from river and lake sediments includes an electric conveying device, a temperature-controlled heating rod, a water-insulating blanket, a sediment water-phosphorus recovery blanket, and a power supply module. The electric conveying device is a cylindrical device integrally molded from acid and alkali resistant conductive plastic, with a conical bottom, a porous surface covered with a water-permeable cloth, and a miniature submersible pump installed inside. The water-insulating blanket is located on the outer ring of the sediment water-phosphorus recovery blanket and is laid at the river / lake sediment-water interface. The electric conveying device and the temperature-controlled heating rod are installed below the sediment water-phosphorus recovery blanket. The miniature submersible pump is used to pump pore water from phosphorus-rich sediments to the sediment water-phosphorus recovery blanket. The power supply module provides power to the electric conveying device, the miniature submersible pump, and the temperature-controlled heating rod.

[0008] Furthermore, the electric guide device is 20-50cm long and 10-20cm in diameter, and is installed as an anode or cathode at intervals of 0.5-1.5m below the sediment water-phosphorus recovery blanket.

[0009] Furthermore, the electric conveyor device serving as the anode is filled with calcium-magnesium ore, and the calcium-magnesium ore is electrolyzed using H2O generated by the anode. + Obtain Ca 2+ and Mg 2+ The pH of the internal circulating water is adjusted to 7-9 to provide a suitable pH for the formation of calcium-phosphorus and magnesium-phosphorus precipitation, as well as for the accelerated release of phosphorus from the bottom sediment.

[0010] Furthermore, the temperature-controlled heating rod is 20-50cm long and 3-5cm in diameter, and is used to provide a suitable temperature for accelerating the release of phosphorus from the bottom mud of the covered area.

[0011] Furthermore, the water-barrier blanket is 5m-8m long and 3m-5m wide, with an outer ring 0.5m-0.8m wide and filled with bentonite. The interior is hollow and overlapped with waterproof geotextile. This is used to prevent phosphorus from the sediment in the covered area from being released into the water body and to provide or maintain an anaerobic environment for the accelerated release of phosphorus from the sediment in the covered area.

[0012] Furthermore, the water-resistant blanket has circular buckles around its perimeter for easy splicing and laying.

[0013] Furthermore, the sediment water and phosphorus recovery blanket is embedded in the inner ring of the upper water-isolation blanket, with a thickness of 5cm-8cm. The upper layer is a water-proof cloth, the middle layer consists of a hollow pad, an environmentally friendly phosphorus adsorption material layer, and a phosphorus removal filter material layer from top to bottom, and the lower layer is a water-permeable cloth. The phosphorus-rich sediment pore water pumped by the micro submersible pump enters the hollow pad.

[0014] Furthermore, the environmentally friendly phosphorus adsorption material is porous biochar, used to adsorb calcium-phosphorus precipitate particles, magnesium-phosphorus precipitate particles and phosphate ions; the phosphorus removal filter layer is used to adsorb residual phosphorus in the pore water of the bottom sediment.

[0015] Furthermore, the power supply module includes a solar power supply device, a wind power generation device, and a DC regulated power supply.

[0016] A method for in-situ separation and recovery of phosphorus from river and lake sediments, using the aforementioned apparatus, includes the following steps:

[0017] Install the electric guide device and temperature-controlled heating rod into the installation port below the mud-water-phosphorus recovery blanket;

[0018] Lay the water-isolation blanket and the sediment-phosphorus recovery blanket at the river and lake mud-water interface;

[0019] The temperature-controlled heating rod and the miniature submersible pump of the electric guide device are connected to the power supply module through wires. The electric guide devices in the same row are connected in series as anode and cathode, respectively, and connected to the positive and negative terminals of the DC regulated power supply in the power supply module.

[0020] After the electric guide pumping device for in-situ separation and recovery of phosphorus in river and lake sediment is laid, let it stand until the device is in close contact with the sediment, then turn on the heating switch controller and control the temperature at 25-35℃.

[0021] After heating for 1-3 days, the electric guide pump is turned on. Under suitable temperature, dissolved oxygen and pH conditions, the phosphorus in the sediment is accelerated to be separated and released. Under the action of the electric field, the phosphorus migrates rapidly with the sediment water to the electric guide pump. After being collected and stored for 1-2 days, it is pumped to the sediment water phosphorus recovery blanket. After adsorption treatment, it is used as internal circulating water to supplement the sediment in the coverage area, thus achieving efficient separation and recovery of sediment phosphorus.

[0022] By employing the above-mentioned technical devices and methods, this invention can achieve the reduction and remediation of phosphorus in river and lake sediments and its resource recovery, specifically with the following beneficial effects:

[0023] (1) This invention integrates the accelerated release of phosphorus from sediment to pore water, rapid collection and efficient enrichment of phosphorus in pore water, and realizes the reduction and remediation of phosphorus in river and lake sediments and its resource recovery.

[0024] (2) This invention regulates dissolved oxygen, temperature and pH from three dimensions, which can accelerate the release of endogenous phosphorus from sediment in different types of water bodies into pore water. The treatment cycle is short, and it is not limited by seasonality and has strong universality.

[0025] (3) The shift from “slow release of phosphorus from bottom sediment pore water to overlying water” to “rapid collection of bottom sediment phosphorus by electric discharge with pore water” and from “adsorption of phosphorus by overlying water and phosphorus adsorption material surface disturbance” to “mixing of phosphorus-rich bottom sediment pore water-precipitation of calcium phosphorus and magnesium phosphorus-phosphorus removal-phosphorus removal by environmentally friendly adsorption materials-adsorption of residual phosphorus by phosphorus removal filter media” has enabled rapid collection and efficient enrichment of phosphorus in pore water.

[0026] (4) This device is detachable and modular, which is convenient for transportation and large-scale installation. No remediation agents are required during the phosphorus recovery process of the bottom mud. It is economical, environmentally friendly and highly operable on site. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of an electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments according to the present invention.

[0028] Figure 2 This is a partial structural schematic diagram of the sediment water and phosphorus recovery blanket of the present invention;

[0029] Figure 3 This is a bottom view schematic diagram of the assembly module of the water-isolation blanket and the sediment water-phosphorus recovery blanket of the present invention;

[0030] Figure 4 This is a cross-sectional schematic diagram of the water-resistant insulating blanket of the present invention.

[0031] In the diagram: 1—Electric guide pump device, 1-1—Miniature submersible pump, 1-2—Calcium and magnesium minerals, 1-3—Electric guide pump device mounting port, 1-4—Anode wire, 1-5—Cathode wire, 2—Temperature-controlled heating rod, 2-1—Heating rod mounting port, 2-2—Wire, 3—Water-proof blanket covering, 3-1—Ring buckle, 3-2—Geotextile waterproof fabric, 3-3—Bentonite, 4—Sediment water and phosphorus recovery blanket, 4-1—Waterproof cloth, 4-2—Hollow core mat, 4-3—Environmentally friendly phosphorus adsorption material layer, 4-4—Phosphorus removal filter layer, 4-5—Permeable cloth, 5—Power supply module. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] This invention is used to treat 1000m 2 Taking a 30cm thick layer of phosphorus-rich polluted sediment in a lake as an example, an electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments is adopted to accelerate the release and recovery of phosphorus from the sediment. This device can isolate the overlying water, reduce the amount of phosphorus to be treated in the sediment, and prevent the released sediment phosphorus from spreading to the overlying water. The isolation blanket and phosphorus adsorption blanket, together with temperature-controlled heating rods and electric discharge devices, can accelerate the separation, release, enrichment, and recovery of phosphorus from the sediment without seasonal limitations.

[0034] like Figure 1-4As shown, an electric conveying system for in-situ separation and recovery of phosphorus in river and lake sediment includes an electric conveying device 1, a temperature-controlled heating rod 2, a water-insulating blanket 3, a sediment water-phosphorus recovery blanket 4, and a power supply module 5.

[0035] The electric guide device 1 is a cylindrical device integrally formed from acid and alkali resistant conductive plastic. It has a conical bottom, a porous surface covered with a water-permeable cloth, a length of 30cm and a diameter of 10cm. It can be installed as an anode or cathode at 1.0m intervals below the bottom sediment water and phosphorus recovery blanket 4.

[0036] The electric guide pump 1 is equipped with a miniature submersible pump 1-1, which is used to pump the pore water of phosphorus-rich sediment to the sediment water-phosphorus recovery blanket 4. The low-phosphorus sediment pore water after mixing and adsorption treatment is used as internal circulating water to supplement the sediment in the coverage area.

[0037] The electric conveyor device 1, which serves as the anode, is filled with calcium-magnesium ore 1-2, and can utilize the H generated by anode electrolysis. + Obtain Ca 2+ and Mg 2+ The pH of the internal circulating water is adjusted to 7-9 to provide a suitable pH for the formation of calcium-phosphorus and magnesium-phosphorus precipitation, as well as for the accelerated release of phosphorus from the bottom sediment.

[0038] The temperature-controlled heating rod 2 is 30cm long and 3cm in diameter. It can also be installed below the sediment water and phosphorus recovery blanket 4 to provide a suitable temperature for the accelerated release of phosphorus from the sediment in the covered area.

[0039] like Figure 3 and Figure 4 As shown, the water-isolation blanket 3 and the sediment water-phosphorus recovery blanket 4 can be assembled. The blanket is 7m long, 4m wide, and 0.6m wide on the outer ring. It is filled with bentonite 3-3 and has a hollow interior that is overlapped with waterproof geotextile 3-2. This can prevent the release of phosphorus from the sediment in the covered area into the water body and provide or maintain an anaerobic environment for the accelerated release of phosphorus from the sediment in the covered area.

[0040] The water-barrier blanket 3 is located around the outer ring of the sediment water-phosphorus recovery blanket 4, and has circular buckles 3-1 around it for easy splicing and laying; the sediment water-phosphorus recovery blanket 4 is on the inner ring, with a thickness of 6cm, as shown in the image. Figure 2 As shown, the upper layer is a waterproof cloth 4-1, the middle layer is a hollow pad 4-2, an environmentally friendly phosphorus adsorption material layer 4-3, and a phosphorus removal filter material layer 4-4, and the lower layer is a permeable cloth 4-5. The environmentally friendly phosphorus adsorption material layer 4-3 can be porous biochar, used to adsorb calcium-phosphorus precipitates, magnesium-phosphorus precipitates, and phosphate ions, etc., and can be directly used in agriculture; the phosphorus removal filter material layer 4-4 is used to adsorb residual phosphorus in the pore water of the bottom sediment, and can be desorbed and recycled.

[0041] The power supply module 5 includes a solar power supply device, a wind power generation device, and a DC regulated power supply, which can supply power to the electric guide pump 1, the micro submersible pump 1-1, and the temperature-controlled heating rod 2.

[0042] This invention also provides a method for in-situ separation and recovery of phosphorus from river and lake sediments, using the aforementioned apparatus. The method includes the following steps:

[0043] (1) Install the electric guide device 1 and the temperature control heating rod 2 into the installation port below the mud water phosphorus recovery blanket 4;

[0044] (2) Lay the water-isolation blanket 3 and the bottom mud-water-phosphorus recovery blanket 4 at the mud-water interface of the river and lake;

[0045] (3) Connect the temperature-controlled heating rod 2 and the miniature submersible pump 1-1 of the electric guide device 1 to the power supply module 5 through the wire 2-2. The electric guide devices 1 in the same row are connected in series and serve as anode and cathode respectively. They are connected to the positive and negative terminals of the DC regulated power supply in the power supply module 5 through the anode wire 1-4 and the cathode wire 1-5 respectively.

[0046] (4) After the electric guide device for in-situ separation and recovery of phosphorus in river and lake sediment is laid, let it stand until the device is in close contact with the sediment, and turn on the heating switch controller to make the temperature control heating rod 2 start working and control the temperature at 30°C.

[0047] (5) After the heating time is maintained for 2 days, turn on the switch of the electric guide device 1 (12h on - 12h off). Under the suitable temperature, dissolved oxygen and pH environment, the phosphorus in the bottom mud is accelerated to migrate to the electric guide device 1 with the bottom mud water under the action of the electric field. After being collected and stored for 1 day, it is pumped to the bottom mud water phosphorus recovery blanket 4. After adsorption treatment, it is used as the bottom mud of the internal circulation water to supplement the bottom mud of the coverage area, and finally the efficient separation and recovery of bottom mud phosphorus is achieved.

[0048] In addition to using a flexible overlying insulating blanket to provide an anaerobic environment for phosphorus release from sediment, the device of this invention also employs a temperature-controlled heating rod to provide a suitable temperature and calcium-magnesium ore to adjust the pH of the internal circulating water to provide a weakly alkaline environment. This enables the accelerated release of endogenous phosphorus from sediment into pore water in different types of water bodies. Then, under the action of an electric field, the phosphorus released from the sediment can migrate rapidly towards the electric guide device and be collected, solving the problem of slow diffusion of phosphorus released from sediment into the overlying water. Finally, the collected phosphorus in the sediment pore water is pumped by a miniature submersible pump of the electric guide device to the sediment water phosphorus recovery blanket for filtration and washing, which can achieve efficient enrichment of phosphorus released from sediment, while the filtered water is internally circulated to replenish the sediment in the covered area.

[0049] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. An electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments, characterized in that: The system includes an electric guide pump, a temperature-controlled heating rod, an upper water-insulating blanket, a sediment-water-phosphorus recovery blanket, and a power supply module. The electric guide pump is a cylindrical device integrally molded from acid and alkali resistant conductive plastic, with a conical bottom, a porous surface covered with a permeable cloth, and a miniature submersible pump installed inside. The upper water-insulating blanket is located on the outer ring of the sediment-water-phosphorus recovery blanket and is laid at the river / lake sediment-water interface. The electric guide pump and the temperature-controlled heating rod are installed below the sediment-water-phosphorus recovery blanket. The miniature submersible pump is used to pump pore water from phosphorus-rich sediment to the sediment-water-phosphorus recovery blanket. The power supply module provides power to the electric guide pump, the miniature submersible pump, and the temperature-controlled heating rod.

2. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 1, characterized in that: The electric guide device is 20-50cm long and 10-20cm in diameter, and is installed as an anode or cathode under the bottom sediment water and phosphorus recovery blanket at intervals of 0.5-1.5m.

3. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 2, characterized in that: The electric conveyor device, which serves as the anode, is filled with calcium-magnesium ore, and the calcium-magnesium ore is electrolyzed using H2O generated by the anode. + Obtain Ca 2+ and Mg 2 + The pH of the internal circulating water is adjusted to 7-9 to provide a suitable pH for the formation of calcium-phosphorus and magnesium-phosphorus precipitation, as well as for the accelerated release of phosphorus from the bottom sediment.

4. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 1, characterized in that: The temperature-controlled heating rod is 20-50cm long and 3-5cm in diameter, and is used to provide a suitable temperature for the accelerated release of phosphorus from the bottom mud of the covered area.

5. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 1, characterized in that: The water-isolation blanket is 5m-8m long and 3m-5m wide, with an outer ring 0.5m-0.8m wide and filled with bentonite. The interior is hollow and overlapped with waterproof geotextile. It is used to prevent phosphorus from the sediment in the covered area from being released into the water body and to provide or maintain an anaerobic environment for the accelerated release of phosphorus from the sediment in the covered area.

6. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 1, characterized in that: The water-resistant blanket has ring buckles around its perimeter for easy splicing and laying.

7. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 1, characterized in that: The sediment water and phosphorus recovery blanket is embedded in the inner ring of the upper water-isolation blanket, with a thickness of 5cm-8cm. The upper layer is a water-proof cloth, the middle layer consists of a hollow pad, an environmentally friendly phosphorus adsorption material layer and a phosphorus removal filter material layer from top to bottom, and the lower layer is a water-permeable cloth. The phosphorus-rich sediment pore water pumped by the micro submersible pump enters the hollow pad.

8. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 7, characterized in that: The environmentally friendly phosphorus adsorption material is porous biochar, used to adsorb calcium-phosphorus precipitate particles, magnesium-phosphorus precipitate particles and phosphate ions; the phosphorus removal filter layer is used to adsorb residual phosphorus in the pore water of the sediment.

9. The electric discharge system for in-situ separation and recovery of phosphorus from river and lake sediments as described in claim 1, characterized in that: The power supply module includes a solar power supply device, a wind power generation device, and a DC regulated power supply.

10. A method for in-situ separation and recovery of phosphorus from river and lake sediments, using the system described in any one of claims 1-9, the method comprising the following steps: Install the electric guide device and temperature-controlled heating rod into the installation port below the mud-water-phosphorus recovery blanket; Lay the water-isolation blanket and the sediment-phosphorus recovery blanket at the river and lake mud-water interface; The temperature-controlled heating rod and the miniature submersible pump of the electric guide device are connected to the power supply module through wires. The electric guide devices in the same row are connected in series as anode and cathode, respectively, and connected to the positive and negative terminals of the DC regulated power supply in the power supply module. After the electric guide pumping device for in-situ separation and recovery of phosphorus in river and lake sediment is laid, let it stand until the device is in close contact with the sediment, then turn on the heating switch controller and control the temperature at 25-35℃. After heating for 1-3 days, the electric guide pump is turned on. Under suitable temperature, dissolved oxygen and pH conditions, the phosphorus in the sediment is accelerated to be separated and released. Under the action of the electric field, the phosphorus migrates rapidly with the sediment water to the electric guide pump. After being collected and stored for 1-2 days, it is pumped to the sediment water phosphorus recovery blanket. After adsorption treatment, it is used as internal circulating water to supplement the sediment in the coverage area, thus achieving efficient separation and recovery of sediment phosphorus.

Images