Emergency plugging device for hazardous waste landfill seepage prevention

Abstract

The utility model relates to dangerous waste treatment technical field, and disclose a kind of dangerous waste landfill anti-seepage emergency plugging device, including garbage landfill pit and for seepage emergency plugging seepage emergency plugging device, the intersection of inside wall and bottom of pit forms right-angle structure, and anti-seepage structure is equipped in pit interior;Seepage emergency plugging device includes expansion waterstop and double liquid foaming component, double liquid foaming component includes first liquid storage unit, second liquid storage unit, first fragility pipe, second fragility pipe and for making first fragility pipe and second fragility pipe breakage expansion superabsorbent, first liquid storage unit is sealed in first fragility pipe, second liquid storage unit is sealed in second fragility pipe, and superabsorbent is filled in the gap between first fragility pipe and second fragility pipe.This application seepage emergency does not need artificial intervention, and seepage emergency plugging device realizes the quick solution to dangerous waste landfill seepage hidden danger.

Description

Technical Field

[0001] This utility model relates to the field of hazardous waste treatment technology, specifically to an emergency sealing device for preventing leakage in hazardous waste landfills. Background Technology

[0002] Hazardous waste landfills are critical sites for handling toxic, harmful, and corrosive hazardous wastes. Their leak-proof systems are the core barrier preventing waste from contacting the surrounding soil and groundwater. Leakage can lead to environmental pollution and health risks; therefore, leak-proof emergency sealing devices are crucial equipment for rapid response and containing the spread of pollution.

[0003] For example, application number 202021370798.6 describes a seepage barrier structure for rigid landfills for hazardous waste. While it possesses a certain seepage prevention capability, numerous problems have been exposed in practical applications. During long-term use, the concrete base slab and sidewalls of rigid landfills are susceptible to shrinkage cracks or cracks due to settlement at the junction of the base and sidewalls due to complex internal stresses and potential foundation settlement. Once cracks appear, the integrity of the seepage barrier layer is compromised, allowing hazardous waste leachate to leak into the surrounding soil and groundwater, causing pollution to the ecological environment. Therefore, we propose an emergency sealing device for seepage prevention in hazardous waste landfills to address the aforementioned problems. Utility Model Content

[0004] The purpose of this utility model is to provide an emergency sealing device for preventing leakage in hazardous waste landfills, in order to solve the problem mentioned in the background art that cracks are easily generated at the junction of the bottom and sidewalls of rigid hazardous waste landfills due to shrinkage or settlement. Once cracks appear, they will damage the integrity of the anti-seepage layer, leading to leakage of hazardous waste leachate, polluting the surrounding soil and groundwater, and causing ecological and environmental damage.

[0005] To achieve the above objectives, this utility model provides the following technical solution: An emergency sealing device for preventing leakage in a hazardous waste landfill includes a landfill pit and an emergency sealing device for preventing leakage. The pit is rectangular in shape, and the junction of the inner wall and the bottom of the pit forms a right-angle structure. The pit is equipped with an anti-leakage structure. The leakage emergency sealing device includes an expanding water-stop strip and a two-component foaming assembly. The two-component foaming assembly includes an independently packaged first liquid storage unit, a second liquid storage unit, a first brittle tube, a second brittle tube, and an expanding superabsorbent resin for rupturing the first and second brittle tubes. The first liquid storage unit is sealed inside the first brittle tube, and the second liquid storage unit is sealed inside the second brittle tube. The first and second brittle tubes are coaxially connected with a gap at the connection point, and the superabsorbent resin fills the gap.

[0006] Preferably, the seepage-proof structure consists of, from bottom to top, a clay protective layer laid on the foundation pit base, a bentonite waterproof blanket, a high-density polyethylene geomembrane, a long-filament geotextile, a composite geogrid drainage net, and a leachate diversion layer, wherein the thickness of the clay protective layer is cm.

[0007] Preferably, the dual-liquid foaming component is located inside the right-angle structure and is embedded between the high-density polyethylene geomembrane and the bentonite waterproof blanket, and the wall thickness of the first brittle tube and the second brittle tube is 0.1 mm to 0.3 mm.

[0008] Preferably, the first liquid storage unit contains an isocyanate prepolymer, and the second liquid storage unit contains a polyol containing a catalyst; when the expanding superabsorbent resin expands upon contact with the leachate and squeezes the first and second brittle tubes to cause them to rupture, the liquids in the two liquid storage units mix and a foaming reaction occurs.

[0009] Preferably, the expansion waterstop strip is made of water-swellable rubber and is installed at the top corner of the right-angle structure of the foundation pit. The contact surface between the expansion waterstop strip and the foundation pit is coated with butyl sealant.

[0010] Preferably, the foundation pit has a structure with a high perimeter and a low center, and the composite geogrid drainage net works in conjunction with the leachate diversion layer to guide the leachate to the collection area in the middle of the foundation pit.

[0011] Compared with the prior art, the beneficial effects of this utility model are: 1. This application addresses the problem of leakage caused by cracks at the junction of the inner wall and bottom of existing hazardous landfill foundations due to stress and settlement. The leakage emergency sealing device can directly act on the weakest part most prone to leakage, reducing the risk of leachate overflow from the source.

[0012] 2. The dual-liquid foaming component triggers a reaction by expanding a highly absorbent resin. When leachate enters, stress is concentrated at the pre-fabricated microcracks, causing the local stress to instantly exceed the ultimate strength, thereby triggering rapid crack propagation and immediate rupture of the brittle tube. The isocyanate prepolymer is then mixed with a catalyst-containing polyol to produce a large amount of foam, which can deeply fill the cracks and surrounding voids, achieving high-strength and permanent sealing, significantly improving the success rate and durability of emergency sealing.

[0013] 3. The dual-liquid foaming component is embedded between the high-density polyethylene geomembrane and the bentonite waterproof blanket, and the expansion waterstop strip is set at the right-angle apex. Both are closely integrated with the original seepage prevention structure of the foundation pit, which not only does not damage the original protection system, but also adds emergency protection on the basis, forming a dual line of defense of conventional protection plus emergency sealing. Attached Figure Description

[0014] Figure 1This is an overall side view of the present invention; Figure 2 For the present utility model Figure 1 Enlarged view of area A in the middle; Figure 3 This is a schematic diagram of the junction between the expansion sealing strip of this utility model and the inner wall and bottom of the foundation pit; Figure 4 This is a side view of the dual-liquid foaming component of this utility model; Figure 5 This is a side view of the foundation pit and leakage emergency sealing device and anti-leakage structure of this utility model. Figure 6 This is a schematic diagram of the expanding superabsorbent resin and brittle tube structure of this utility model.

[0015] In the diagram: 1. Foundation pit; 2. Emergency sealing device for leakage; 21. Expandable waterstop strip; 22. Two-component foaming assembly; 221. First liquid storage unit; 222. Second liquid storage unit; 223. First brittle tube; 224. Second brittle tube; 225. Superabsorbent resin; 3. Leak-proof structure; 31. Clay protective layer; 32. Bentonite waterproof blanket; 33. High-density polyethylene geomembrane; 34. Long-filament geotextile; 35. Composite geogrid; 36. Leachate diversion layer; 226. Microcracks. Detailed Implementation

[0016] 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.

[0017] Please see the appendix Figure 1 , Figure 2 and Figure 5As shown, an emergency sealing device for preventing leakage in a hazardous waste landfill includes a landfill pit 1 and an emergency sealing device 2 for preventing leakage. The pit 1 is in the shape of a rectangular container, and the junction of the inner wall and the bottom of the pit 1 forms a right-angle structure. The pit 1 has a structure that is high around the edges and low in the middle, which facilitates the collection of leachate. The pit 1 is equipped with an anti-leakage structure 3 inside. The seepage-proof structure 3, from bottom to top, consists of a clay protective layer 31 laid on the foundation pit 1, a bentonite waterproof blanket 32, a high-density polyethylene geomembrane 33, a long-fiber geotextile 34, a composite geogrid 35, and a leachate diversion layer 36. The clay protective layer 31 is 30cm thick. The bentonite waterproof blanket 32 ​​is a sodium-based bentonite waterproof blanket (Taian Lutong Building Materials Co., Ltd.), with a water swelling rate ≥24 times and a permeability coefficient ≤5×10⁻¹¹cm / s. The high-density polyethylene geomembrane 33 is a GH-2S smooth geomembrane (Dongfang Yuhong), with a thickness of 1... 0mm and 1.5mm thick geotextiles, 6m wide, with a limit deviation ≥-3% and tensile strength ≥30MPa; product model 34 is spunbond needle-punched geotextile (Dezhou Zhongrui Geotechnical Materials Co., Ltd.); product model 35 is three-dimensional composite drainage net (Dezhou Nuolai New Materials Co., Ltd.), with a core thickness of 7.6mm, longitudinal water conductivity ≥2.5×10⁻³m² / s, geotextile weight 200g / m², and peel strength ≥2.1kN / m. This is a landfill leachate drainage layer, replacing the traditional gravel layer, improving drainage efficiency by 30%. The composite geotextile drainage net 35, in conjunction with the leachate drainage layer 36, guides the leachate to the collection area in the middle of the foundation pit 1, facilitating centralized treatment of the leachate, reducing its accumulation in the foundation pit, and lowering the risk of leakage.

[0018] Please see the appendix Figure 1 , Figure 3 , Figure 4 and Figure 6As shown, the leakage emergency sealing device 2 includes an expanding water-stop strip 21 and a two-component foaming assembly 22. The two-component foaming assembly 22 includes an independently packaged first liquid storage unit 221, a second liquid storage unit 222, a first brittle tube 223, a second brittle tube 224, and an expanding superabsorbent resin 225 for rupturing the first brittle tube 223 and the second brittle tube 224. The first liquid storage unit 221 is sealed inside the first brittle tube 223, and the second liquid storage unit 222 is sealed inside the second brittle tube 224. The first brittle tube 223 and the second brittle tube 224 are coaxially connected with a gap at the connection point. The superabsorbent resin 225 fills the gap, and the gap width is... The thickness is 0.5mm to 2mm. This range ensures that the superabsorbent resin 225 tightly fills the gaps when dry, and also allows it to quickly convert the expansion force into compressive force on the thin-walled brittle tube when it expands upon contact with water, meeting the emergency requirement of rupture within 3 to 5 seconds. It also matches the easily ruptured characteristics of the brittle tube with a wall thickness of 0.1 to 0.3mm. The superabsorbent resin 225 is model WHS700C (Wanhua Chemical Group Co., Ltd.), with a water absorption capacity ≥700g / g and a pressure absorption capacity ≥25g / g; its elastic modulus is 1200-1500Pa (gel state), corresponding to an expansion pressure of 0.6-1.2MPa in the enclosed space. The two-component foaming component 22 is located inside the right-angled structure and is embedded between the high-density polyethylene geomembrane 33 and the bentonite waterproof blanket 32. The wall thickness of both the first brittle tube 223 and the second brittle tube 224 is 0.1mm to 0.3mm, making them prone to rupture. The first liquid storage unit 221 contains isocyanate prepolymer, and the second liquid storage unit 222 contains polyol containing a catalyst. When the expanding superabsorbent resin 225 expands upon contact with leachate and squeezes the first brittle tube 223 and the second brittle tube 224 to cause them to rupture, the liquids in the two liquid storage units mix and a foaming reaction occurs.

[0019] It should be noted that in this embodiment, the first brittle tube 223 and the second brittle tube 224 are made of glass microcatheter or thin-walled ceramic tube. The molecular structure is compact and lacks ductility, so stress cannot be dispersed through plastic deformation. At the same time, annular microcracks 226 (depth 0.05-0.1mm) are pre-set on the outer wall of the brittle tube joint. Combined with the ultra-thin wall thickness design of 0.1mm-0.3mm, the structural strength is greatly weakened. When subjected to a small pressure (about 0.5-1MPa) generated by the expansion of the superabsorbent resin 225, the stress will concentrate at the pre-made microcracks 226, causing the local stress to exceed the ultimate strength instantly, thereby triggering the rapid propagation of the crack and realizing the immediate rupture of the brittle tube. In addition, the inner wall of the brittle tube is coated with a silane coupling agent (such as KH-550) to form an inert layer, which does not react with the liquid in the liquid storage unit and can ensure the sealing when not triggered, thereby meeting the functional requirements of easy breakage.

[0020] Furthermore, the superabsorbent resin 225 (preferably sodium polyacrylate-acrylamide copolymer resin) rapidly absorbs water and swells within 5-10 seconds after contacting the leachate (the high concentration of ions in the leachate slightly slows down the expansion rate; the expansion time in pure water can be shortened to 3-5 seconds), achieving a volume expansion rate of 80-100 times. The mechanical pressure generated after water saturation can reach 0.5-1.2 MPa, fully meeting the rupture threshold of thin-walled brittle tubes (wall thickness 0.1-0.3 mm). It remains stable in the acidic or alkaline environment of the leachate (pH typically 4-12) and does not react with the isocyanate prepolymer or polyol in the two-liquid foaming component 22, ensuring a tight seal when not triggered. After absorbing water, the superabsorbent resin 225 forms a gel-like network that can uniformly fill the gaps between brittle pipe joints, ensuring that the expansion force is evenly transmitted to both pipe walls. When leachate enters the gaps between the brittle pipe joints, the superabsorbent resin 225 rapidly absorbs water and expands, and the resulting pressure is concentrated at the pre-existing cracks in the brittle pipe. Due to the material's lack of ductility and extremely thin wall thickness, it ruptures instantaneously when the local stress exceeds the ultimate strength, releasing the two-component components and initiating a foaming reaction. As clearly described in Chinese invention patent CN115784705A, similar superabsorbent resin 225 can expand 80-100 times within 5-10 seconds in tunnel dynamic water environments (including high ion seepage), and when combined with two-component grout, it can achieve a water-blocking rate of over 98%, verifying its rapid expansion and high-pressure characteristics.

[0021] When shrinkage cracks or settlement lead to cracks at the junction of the bottom and sidewalls, compromising the integrity of the impermeable layer, the leachate comes into contact with the expanding superabsorbent resin 225 in the two-liquid foaming component 22. The superabsorbent resin 225 expands upon contact with the leachate. Because it is located in the gap between the first brittle tube 223 and the second brittle tube 224, the pressure generated by the expansion concentrates on the pre-cracked area of ​​the brittle tube. Since the brittle tube has extremely low local strength after optimization by the microcracks 226 and a wall thickness of only 0.1mm to 0.3mm, it will rapidly rupture under pressure. After the brittle tube ruptures, the isocyanate prepolymer in the first storage unit 221 and the catalyst-containing polyol in the second storage unit 222 flow out and mix, undergoing a foaming reaction to generate a large amount of foam. This foam can deeply fill the cracks and surrounding voids, achieving high-strength, permanent sealing of the cracks, thereby effectively preventing further leakage of leachate. The expandable waterstop strip 21 is made of water-swellable rubber and is installed at the apex of the right-angle structure of the foundation pit 1. The contact surface between the expandable waterstop strip 21 and the foundation pit 1 is coated with butyl sealant. When cracks appear in the right-angle and apex structures where the inner wall of the foundation pit meets the bottom, the integrity of the seepage prevention layer is damaged, and leachate begins to leak. When it comes into contact with the expandable waterstop strip 21 at the apex, the expandable waterstop strip 21, being made of water-swellable rubber, expands rapidly upon contact with water. Combined with the adhesive effect of the butyl sealant, it quickly fills the gaps, forming a preliminary sealing barrier and delaying the spread of leachate.

[0022] After the two-component foaming component 22 is sealed, a small amount of leachate may remain unsealed and continue to diffuse towards the apex of the right-angled structure. At this point, the expansion sealing strip 21 (made of water-swellable rubber) located at the apex begins to function. The sealing strip expands rapidly upon contact with the leachate, and together with the butyl sealant applied to the contact surface, it enhances the bonding and sealing effect, further filling the remaining gaps and forming a secondary barrier to ensure that the leakage channel is completely sealed.

[0023] Working principle: When the right-angle structure at the junction of the inner wall and bottom of the foundation pit 1 of the hazardous waste landfill develops cracks due to long-term stress, foundation settlement and other factors, and the integrity of the seepage prevention layer is damaged, the hazardous waste leachate first penetrates into the deep layer of the seepage prevention structure 3 and directly contacts the two-liquid foaming component 22 buried between the high-density polyethylene geomembrane 33 and the bentonite waterproof blanket 32. Leachate rapidly penetrates the gap between the first brittle tube 223 and the second brittle tube 224, coming into contact with the expanding superabsorbent resin 225 filling it. Upon contact with water, the superabsorbent resin 225 rapidly expands in volume, generating outward compressive force. Stress concentrates at the pre-fabricated microcracks 226, causing the localized stress to instantly exceed the ultimate strength, leading to rapid crack propagation and immediate rupture of the brittle tube. This force acts directly on the brittle tube wall, which is only 0.1mm to 0.3mm thick. Due to the fragility of the brittle tube material, it ruptures instantly under the expanding force, causing the isocyanate prepolymer in the first storage unit 221 and the catalyst-containing polyol in the second storage unit 222 to lose their encapsulation protection. They rapidly flow out through the rupture and mix thoroughly, immediately triggering a violent foaming reaction, generating a large amount of highly expandable and adhesive foam. This foam quickly fills the interior and surrounding voids of the crack, forming a high-strength three-dimensional sealing structure, initially blocking the diffusion path of the leachate. If a small amount of leachate remains unsealed, it will continue to spread towards the apex of the right-angled structure. At this point, the expansion sealant 21 (made of water-swellable rubber) located at the apex begins to function. The sealant expands rapidly upon contact with the leachate, and together with the butyl sealant applied to the contact surface, it enhances the bonding and sealing effect, further filling the remaining gaps and forming a secondary barrier to ensure that the leakage channel is completely sealed. At the same time, the high-middle-high structural design around the foundation pit 1, together with the composite geogrid 35 and the leachate diversion layer 36, works in synergy to efficiently guide the leachate that has not leaked to the central collection area, reducing the amount of leachate accumulated in the foundation pit and reducing the possibility of secondary leakage from the source. The entire process requires no manual intervention. It involves a progressive protection system: first, a double-liquid foaming component 22 is used for sealing; then, an expansion water-stop strip 21 is used for secondary reinforcement; and finally, a diversion system is used to assist in pollution control. This system forms a complete emergency treatment closed loop, enabling a rapid and thorough solution to potential leakage hazards in hazardous waste landfills.

[0024] The contents not described in detail in this specification are existing technologies known to those skilled in the art.

[0025] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A hazardous waste landfill leakage prevention and emergency sealing device, comprising a landfill pit (1) and a leakage emergency sealing device (2) for leakage emergency sealing, characterized in that: The foundation pit (1) is in the shape of a rectangular container. The junction of the inner wall and the bottom of the foundation pit (1) forms a right-angle structure. The foundation pit (1) is provided with a seepage prevention structure (3). The leakage emergency sealing device (2) includes an expanding water-stop strip (21) and a two-liquid foaming assembly (22). The two-liquid foaming assembly (22) includes an independently packaged first liquid storage unit (221), a second liquid storage unit (222), a first brittle tube (223), a second brittle tube (224), and an expanding superabsorbent resin (225) for rupturing the first brittle tube (223) and the second brittle tube (224). The first liquid storage unit (221) is sealed inside the first brittle tube (223), and the second liquid storage unit (222) is sealed inside the second brittle tube (224). The first brittle tube (223) and the second brittle tube (224) are coaxially connected with a gap at the connection point. The expanding superabsorbent resin (225) fills the gap.

2. The emergency sealing device for preventing leakage in hazardous waste landfills according to claim 1, characterized in that: The seepage prevention structure (3) consists of, from bottom to top, a clay protective layer (31), a bentonite waterproof blanket (32), a high-density polyethylene geomembrane (33), a long-fiber geotextile (34), a composite geogrid (35), and a leachate diversion layer (36) laid on the foundation pit (1). The thickness of the clay protective layer (31) is 30 cm.

3. The emergency sealing device for preventing leakage in hazardous waste landfills according to claim 1, characterized in that: The dual-liquid foaming component (22) is located inside the right-angle structure and is embedded between the high-density polyethylene geomembrane (33) and the bentonite waterproof blanket (32). The wall thickness of the first brittle tube (223) and the second brittle tube (224) is 0.1 mm to 0.3 mm.

4. The emergency sealing device for preventing leakage in hazardous waste landfills according to claim 1, characterized in that: The first liquid storage unit (221) contains isocyanate prepolymer, and the second liquid storage unit (222) contains polyol containing catalyst. When the expanding superabsorbent resin (225) expands upon contact with leachate and squeezes the first brittle tube (223) and the second brittle tube (224) to cause them to rupture, the liquids in the two liquid storage units mix and foam.

5. The emergency sealing device for preventing leakage in hazardous waste landfills according to claim 1, characterized in that: The expansion waterstop strip (21) is made of water-swellable rubber and is set at the top corner of the right-angle structure of the foundation pit (1). The contact surface between the expansion waterstop strip (21) and the foundation pit (1) is coated with butyl sealant.

6. The emergency sealing device for preventing leakage in hazardous waste landfills according to claim 2, characterized in that: The foundation pit (1) has a structure with a high center and a high perimeter. The composite geogrid (35) works in conjunction with the leachate guide layer (36) to guide the leachate to the collection area in the middle of the foundation pit (1).

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