Hazardous waste landfill systems and landfill methods

Abstract

The present invention provides a hazardous waste landfill system and landfill method, the system includes a landfill unit, an anti-seepage unit and a discharge platform, the landfill unit includes a plurality of landfill areas, the anti-seepage unit is arranged on the landfill area, the anti-seepage unit includes an anti-seepage layer and an anti-seepage protective layer; the plurality of landfill areas are arranged in sequence from high to low terrain, and the edge of the landfill area with the highest terrain is provided with the said discharge platform that meets the initial landfill operation, so that the hazardous waste ton bags are suspended from the landfill area with the highest terrain, so that the hazardous waste ton bags form a temporary road connected to the discharge platform. The present invention sets an anti-seepage protective layer to avoid the damage of the anti-seepage layer, the landfill method reduces the amount of leachate generated by solidifying the hazardous waste and then landfilling it, the initial landfill uses a crane to lift the ton bags of hazardous waste on the discharge platform to form a temporary exit road to meet the subsequent transportation and landfill operations, and the exit road is cancelled to avoid the damage of the anti-seepage layer while increasing the landfill storage capacity.

Description

Technical Field

[0001] The invention relates to the technical field of waste landfill, in particular to a hazardous waste landfill system and a landfill method. Background Art

[0002] In recent years, with the rapid development of my country's economy, a large amount of waste has been generated and needs to be treated, especially the treatment of hazardous waste has gradually received attention in the industry. Landfill technology is currently the most commonly used method for hazardous waste treatment due to its large treatment capacity and strong applicability. It is also one of the more ideal treatment methods for the final treatment of hazardous waste.

[0003] At present, in the existing hazardous waste landfill technology, the landfill units are generally not divided or have few divisions, and are not covered in time during the landfill process, and the separation of clean and dirty water cannot be achieved, which easily leads to rainwater directly entering the hazardous waste to form leachate; the anti-seepage units are basically set up in accordance with standard specifications. Due to insufficient or improper setting of the protective layer, the geomembrane layer is easily damaged during actual construction and / or landfill use, causing the leachate in the landfill area to leak into the soil and pollute the surrounding environment; in order to meet the bottom landfill operations in the landfill area, it is usually considered to set up a permanent exit road in the landfill area, which not only occupies storage capacity but also increases the risk of damaging the anti-seepage units. In addition, existing hazardous waste is often directly loaded and transported to landfills without being treated. In addition to being easily left behind during transportation and causing secondary pollution, the hazardous waste contains a high water content and many active harmful heavy metals and salts, which can easily lead to large amounts of leachate and clog the leachate collection system, making the hazardous waste pile unstable and threatening the safety of the landfill. At the same time, harmful heavy metals are enriched in the leachate, which not only makes subsequent treatment difficult and costly, but also increases the risk of environmental pollution from heavy metal migration. Summary of the invention

[0004] The purpose of the present invention is to propose a hazardous waste landfill system and landfill method to solve the problems of secondary pollution during the transportation of hazardous waste and waste pile safety, easy clogging of leachate drainage, and damage to anti-seepage units in the existing landfill systems and landfill methods.

[0005] The present invention provides a hazardous waste landfill system, comprising a landfill unit, an anti-seepage unit and a discharge platform, wherein the landfill unit comprises a plurality of landfill areas, the anti-seepage unit is arranged on the landfill area, and the anti-seepage unit comprises an anti-seepage layer and an anti-seepage protective layer stacked in sequence from the inside to the outside;

[0006] Several landfill areas are arranged in sequence from high to low terrain. The edge of the landfill area with the highest terrain is provided with an unloading platform that meets the requirements of initial landfill operations. Ton bags of hazardous waste are hoisted from the landfill area with the highest terrain so that the ton bags of hazardous waste form a temporary road connected to the unloading platform. The ton bags of hazardous waste are formed by solidified bags of hazardous waste.

[0007] The hazardous waste landfill system proposed by the present invention has the following beneficial effects: the anti-seepage protective layer is set on the landfill area to effectively protect the anti-seepage layer from damage and drain the leachate into the leachate drainage system set at the bottom of the landfill area, thereby preventing the soil around the landfill unit from being polluted by the leachate. A crane is used to lift the hazardous waste ton bag containing the hazardous waste solid body on the unloading platform to form a temporary landfill road to meet the subsequent transportation and landfill operations of the hazardous waste solid body. The elimination of the landfill road not only increases the landfill storage capacity, but also further prevents the anti-seepage layer from being damaged.

[0008] In addition, the hazardous waste landfill system provided by the present invention may also have the following additional technical features:

[0009] Furthermore, the landfill area is surrounded by a landfill area bottom and a landfill area slope extending upward from the landfill area bottom;

[0010] The anti-seepage protective layer comprises a first anti-seepage protective layer and a second anti-seepage protective layer, wherein the first anti-seepage protective layer is arranged on the slope of the landfill area and comprises a first geotextile layer and a bagged sand layer stacked from inside to outside;

[0011] The second anti-seepage protective layer is arranged on the bottom of the landfill area, and includes a second geotextile layer, a geocomposite drainage net layer and a geomat layer stacked from bottom to top;

[0012] The first geotextile layer and the second geotextile layer are connected in one piece.

[0013] Furthermore, the hazardous waste landfill system also includes an anchoring platform, the unloading platform is arranged on the anchoring platform, and the edges of the anti-seepage layer and the first geotextile layer are fixed on the anchoring platform.

[0014] Furthermore, the hazardous waste landfill system also includes a temporary covering unit, and the edge of the temporary covering unit is fixed to the anchoring platform by weight or expansion screws to temporarily cover the landfill area.

[0015] Furthermore, the temporary covering unit is a high-density polyethylene geomembrane, and the thickness of the temporary covering unit is 0.75-1.0 mm.

[0016] The present invention also provides a hazardous waste landfill method, which is applied to the above hazardous waste landfill system. The hazardous waste landfill method comprises the following steps:

[0017] The hazardous waste landfill method comprises the following steps:

[0018] Dividing the landfill unit into a plurality of landfill areas, laying an impermeable layer on the slope and the bottom of each landfill area, and laying an impermeable protective layer on the impermeable layer to form an impermeable unit;

[0019] Several of the landfill areas are arranged in sequence from high to low terrain. An unloading platform that meets the needs of initial landfill operations is provided at the edge of the landfill area with the highest terrain. Hazardous waste is solidified and bagged to form ton bags of hazardous waste. A crane is used on the unloading platform to lift the ton bags of hazardous waste into the landfill area with the highest terrain to form a temporary exit road connecting the unloading platform to meet the subsequent transportation and landfill operations of the ton bags of hazardous waste.

[0020] Furthermore, the hazardous waste landfill method specifically comprises the following steps:

[0021] The landfill unit is divided into several landfill areas, which are arranged in order from high to low according to the terrain. The edge of the landfill area with the highest terrain is provided with a material unloading platform that meets the requirements of the initial landfill operation, and an impermeable layer is laid on the slope and bottom of each landfill area;

[0022] A first geotextile layer and a bagged sand layer are sequentially laid on the anti-seepage layer of the landfill area slope to form a first anti-seepage protective layer, and a second geotextile layer, a geocomposite drainage net layer and a geomat layer are sequentially laid on the anti-seepage layer at the bottom of the landfill area to form a second anti-seepage protective layer, wherein the first geotextile layer and the second geotextile layer are integrally connected;

[0023] Fixing the edges of the anti-seepage layer and the first geotextile layer on an anchoring platform;

[0024] After each of the landfill areas is built, a temporary covering unit is placed on the upper opening, and the edge of the temporary covering unit is fixed to the anchoring platform by weight or expansion screws;

[0025] The temporary covering unit is uncovered, and a crane is used to lift the hazardous waste ton bags onto the unloading platform and place them in the landfill area with the highest terrain to form a temporary road connecting the unloading platform to meet the subsequent transportation and landfill operations of the hazardous waste ton bags. The order of landfilling is from high to low according to the terrain of the landfill area;

[0026] After the landfill is completed, the temporary covering unit is used for covering.

[0027] The hazardous waste landfill method proposed in the present invention has the following beneficial effects: firstly, the hazardous waste is stabilized and solidified into a hazardous waste solid body and bagged, so that the hazardous waste materials can be transported in an organized manner and can play a reinforcing and stabilizing role on the hazardous material pile, thereby avoiding secondary pollution during transportation, reducing the amount of leachate generated during landfilling, and delaying the clogging time of the leachate collection system; by setting an unloading platform at the edge of the landfill area with the highest terrain, the initial landfill is carried out on the unloading platform by using a crane to lift and place ton bags of hazardous waste containing the hazardous waste solid body to form a temporary exit road to meet the subsequent transportation and landfill operations of the hazardous waste solid body, thereby increasing the landfill capacity and avoiding damage to the anti-seepage layer.

[0028] Furthermore, the preparation method of the hazardous waste ton bag is: adding a fixative, a stabilizer and water to the hazardous waste, stirring to form a hazardous waste solid body, and bagging the hazardous waste solid body to form a hazardous waste ton bag.

[0029] Furthermore, the fixing agent is cement, lime or fly ash, and the stabilizer is sodium thiosulfate or a metal chelating agent.

[0030] Furthermore, the hazardous waste landfill method specifically comprises the following steps:

[0031] The landfill unit is divided into several landfill areas, which are arranged in order from high to low according to the terrain. The edge of the landfill area with the highest terrain is provided with a material unloading platform that meets the requirements of the initial landfill operation, and an impermeable layer is laid on the slope and bottom of each landfill area;

[0032] A first geotextile layer and a bagged sand layer are sequentially laid on the anti-seepage layer of the landfill area slope to form a first anti-seepage protective layer, and a second geotextile layer, a geocomposite drainage net layer and a geomat layer are sequentially laid on the anti-seepage layer at the bottom of the landfill area to form a second anti-seepage protective layer, wherein the first geotextile layer and the second geotextile layer are integrally connected;

[0033] Fixing the edges of the anti-seepage layer and the first geotextile layer on an anchoring platform;

[0034] After each of the landfill areas is built, a temporary covering unit is placed on the upper opening, and the edge of the temporary covering unit is fixed to the anchoring platform by weight or expansion screws;

[0035] The temporary covering unit is uncovered, and a crane is used to lift the hazardous waste ton bags onto the unloading platform and place them in the landfill area with the highest terrain to form a temporary road connecting the unloading platform to meet the subsequent transportation and landfill operations of the hazardous waste ton bags. The order of landfilling is from high to low according to the terrain of the landfill area;

[0036] After the landfill is completed, the temporary covering unit is used for covering.

[0037] The hazardous waste landfill method proposed in the present invention has the following beneficial effects: firstly, the hazardous waste is stabilized and solidified into a hazardous waste solid body and bagged, so that the hazardous waste materials can be transported in an organized manner and can play a reinforcing and stabilizing role on the hazardous material pile, thereby avoiding secondary pollution during transportation, reducing the amount of leachate generated during landfilling, and delaying the clogging time of the leachate collection system; by setting an unloading platform at the edge of the landfill area with the highest terrain, the initial landfill is carried out on the unloading platform by using a crane to lift and place ton bags of hazardous waste containing the hazardous waste solid body to form a temporary exit road to meet the subsequent transportation and landfill operations of the hazardous waste solid body, thereby increasing the landfill capacity and avoiding damage to the anti-seepage layer.

[0038] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0040] Figure 1 is a top view of a hazardous waste landfill system according to a first embodiment of the present invention;

[0041] Figure 2 is a longitudinal cross-sectional view of a hazardous waste landfill system according to a first embodiment of the present invention;

[0042] Figure 3 is a cross-sectional schematic diagram of a landfill area of ​​a hazardous waste landfill system according to a first embodiment of the present invention;

[0043] Figure 4 It is a schematic structural diagram of a landfill area slope of a hazardous waste landfill system according to a first embodiment of the present invention;

[0044] Figure 5 It is a schematic structural diagram of the bottom of the landfill area of ​​the hazardous waste landfill system of the first embodiment of the present invention;

[0045] Figure 6 is a schematic diagram of the operation of the hazardous waste landfill system according to the first embodiment of the present invention;

[0046] Figure numbers: 10. landfill area; 11. landfill area bottom; 12. landfill area slope; 13. bottom landfill area; 14. middle landfill area; 20. anti-seepage unit; 21. anti-seepage layer; 22. first anti-seepage protective layer; 221. first geotextile layer; 222. bagged sand layer; 23. second anti-seepage protective layer; 231. second geotextile layer; 232. geocomposite drainage net layer; 233. geomat layer; 30. anchoring platform; 40. temporary covering unit; 50. unloading platform; 60. crane; 70. partition dam. DETAILED DESCRIPTION

[0047] In order to make the purpose, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the accompanying drawings. Several embodiments of the present invention are shown in the accompanying drawings. However, the present invention can be implemented in many different forms and is not limited to the embodiments described herein. On the contrary, the purpose of providing these embodiments is to make the disclosure of the present invention more thorough and comprehensive.

[0048] Please refer to Figure 1 to Figure 6 As shown, the first embodiment of the present invention provides a hazardous waste landfill system, including a landfill unit, an anti-seepage unit 20 and a discharge platform 50.

[0049] The landfill unit includes a plurality of landfill areas 10, and the anti-seepage unit 20 is arranged on the landfill area 10. The anti-seepage unit 20 includes an anti-seepage layer 21 and an anti-seepage protective layer stacked in sequence from the inside to the outside. The anti-seepage protective layer is arranged on the landfill area 10 to effectively protect the anti-seepage layer 21 from damage and to guide the leachate into the leachate drainage system arranged at the bottom 11 of the landfill area, thereby preventing the soil around the landfill unit from being contaminated by the leachate.

[0050] Several landfill areas 10 are arranged in sequence from high to low terrain. The edge of the landfill area 10 with the highest terrain is provided with the unloading platform 50 that meets the requirements of initial landfill operations. Ton bags of hazardous waste are hoisted from the landfill area 10 with the highest terrain so that the ton bags of hazardous waste form a temporary road connected to the unloading platform 50. The ton bags of hazardous waste are formed by solidifying and bagging hazardous waste.

[0051] The crane 60 is used to hoist and lower the hazardous waste ton bags from the landfill area 10 at the end, so that the hazardous waste ton bags form a temporary road connected to the unloading platform 50. The initial landfill can form a temporary road using hazardous waste ton bags, which can eliminate the road to increase the landfill capacity and avoid the damage of the impermeable layer 21.

[0052] In this embodiment, the landfill area 10 has an upper opening and is surrounded by a landfill area bottom 11 and a landfill area slope 12 extending upward from the landfill area bottom 11. The anchoring platform 30 is arranged at the upper opening edge of the landfill area 10.

[0053] The anti-seepage protective layer includes a first anti-seepage protective layer 22 and a second anti-seepage protective layer 23; the first anti-seepage protective layer 22 is arranged on the landfill area slope 12, and includes a first geotextile layer 221 and a bagged sand layer 222 stacked from the inside to the outside. The first geotextile layer 221 and the bagged sand layer 222 arranged on the landfill area slope 12 can effectively protect the anti-seepage layer 21 from damage and guide the leachate into the leachate drainage system arranged at the bottom 11 of the landfill area, thereby preventing the soil around the landfill unit from being contaminated by the leachate.

[0054] The second anti-seepage protective layer 23 is arranged on the bottom 11 of the landfill area, and includes a second geotextile layer 231, a geocomposite drainage net layer 232 and a geomat cushion layer 233 stacked from bottom to top. The second geotextile layer 231, the geocomposite drainage net layer 232 and the geomat cushion layer 233 are arranged on the bottom of the landfill area 10 to protect the anti-seepage layer 21 from damage, and prevent leachate from infiltrating into the soil from the bottom of the landfill area 10.

[0055] The first geotextile layer 221 and the second geotextile layer 231 are connected in one piece, and the edge of the first geotextile layer 221 is fixed on the anchoring platform 30 to prevent the first geotextile layer 221 from slipping.

[0056] In this embodiment, the hazardous waste landfill system further includes an anchoring platform 30, the unloading platform 50 is arranged on the anchoring platform 30, and the edges of the anti-seepage layer 21 and the first geotextile layer 221 are fixed on the anchoring platform 30. The anchoring platform 30 is arranged to prevent the anti-seepage unit 20 from slipping and ensure the anti-seepage effect.

[0057] In this embodiment, the anti-seepage layer 21 includes two layers of high-density polyethylene geomembranes stacked together. High-density polyethylene geomembranes have strong tensile strength, excellent UV resistance, anti-aging and corrosion resistance, and high-density polyethylene geomembranes are used as the anti-seepage layer 21, which has good anti-seepage effect and is more durable.

[0058] In this embodiment, the landfill is provided with five landfill areas 10, namely landfill area 1, landfill area 2, landfill area 3, landfill area 4 and landfill area 5 arranged in a straight line, and partition dams 70 are provided between adjacent landfill areas 10 for separation. The landfill area 1 is located in the highest area of ​​the landfill unit, and the other landfill areas 10 are arranged in descending order according to the order of use and the terrain. This design can make the leachate seep out of the hazardous waste pile as soon as possible and gather at the lowest point, which is conducive to the diversion of sewage and improves the stability of the hazardous waste pile, while reducing the heavy metal content in the leachate and reducing the difficulty and cost of leachate treatment.

[0059] In this embodiment, an unloading platform 50 that meets the requirements of initial landfill operations is provided at the edge of the landfill area 10 with the highest terrain, and the unloading platform 50 is arranged on the anchoring platform 30 .

[0060] In this embodiment, the hazardous waste landfill system also includes a temporary covering unit 40, and the edge of the temporary covering unit 40 is weighted by bagged soil or sand or fixed to the anchoring platform 30 with expansion screws to temporarily cover the upper opening. In order to prevent rainwater from directly entering the hazardous waste pile, the upper opening of the landfilled hazardous waste is temporarily covered by the temporary covering unit 40, which is then uncovered during the landfill operation and immediately covered after the landfill is completed each day, thereby reducing the amount of leachate generated from the source. The edge of the temporary covering unit 40 is fixed to the anchoring platform 30 at the edge of the landfill area 10 by weighting or expansion bolts to prevent the temporary covering unit 40 from slipping.

[0061] Among them, after the construction of the temporary covering unit 40, the bottom of the landfill area slope 12 is weighted with waste tires. Since the rainwater on the covering film cannot be discharged outside the landfill area 10 by gravity, a water collection pit is intentionally formed at the lowest point during the landfill operation, so that the rainwater will naturally gather in the water collection pit and then be pumped out of the landfill area 10 by a portable water pump.

[0062] In this embodiment, the temporary covering unit 40 is a high-density polyethylene geomembrane, and the thickness of the temporary covering unit 40 is 0.75-1.0 mm. The high-density polyethylene geomembrane has strong tensile strength, excellent anti-ultraviolet, anti-aging and corrosion resistance, and the use of high-density polyethylene geomembrane as the temporary covering unit 40 is more durable and prevents rainwater from entering the landfill area 10.

[0063] In this embodiment, the hazardous waste ton bag is formed by bagging after the hazardous waste is solidified. The specific formation steps are as follows: according to the nature of the hazardous waste, it is first stabilized and solidified in a stabilization and solidification workshop, and after 5 to 10 days of curing, its compressive strength can reach 5kg / cm after 5 days of curing. 2 After 10 days of curing, its compressive strength can reach 10kg / cm 2After passing the test, the stabilized and solidified hazardous waste is bagged to form a hazardous waste ton bag, and then the ton bag containing the stabilized and solidified hazardous waste is transported to the landfill area by dump trucks or forklifts 10. Hazardous waste is stabilized and solidified and transported in ton bags to avoid secondary pollution during transportation and reduce the amount of leachate generated during the landfill process.

[0064] Among them, the hazardous waste ton bags are landfilled from the highest landfill area 1, and a certain amount of stabilized and solidified hazardous waste ton bags need to be accumulated. Two slings or ropes are set on the ton bags. When lifting, the hook of the crane 60 is hung on the central part of the slings or ropes. Do not lift the ton bags obliquely, single-sidedly or diagonally. The initial landfill is carried out on the unloading platform 50 by using the crane 60 to lift the ton bags of stabilized and solidified hazardous waste one by one from the bottom of the landfill area 1, until a temporary exit road for the landfill machinery to travel is formed to connect the unloading platform 50. After the landfill machinery enters the site, the hazardous waste is transported to the bottom of the landfill area 11 for paving and compacting. When the thickness of the hazardous waste is filled to more than 1m, the landfill machinery can be driven up to operate. The subsequent transportation and landfill operations directly transport the ton bags of stabilized and solidified hazardous waste to each landfill area 10 through the temporary exit road formed by the initial landfill, and then the landfill machinery is used for layered paving and rolling operations. The use of hazardous waste ton bags in the initial landfill can form a temporary road, which can eliminate the downstream road, increase the landfill capacity and avoid damage to the anti-seepage layer 21.

[0065] In this embodiment, each of the landfill areas 10 is divided into a bottom landfill area 13 and an intermediate landfill area 14. The bottom landfill area 13 is surrounded by the landfill area slope 12 and the landfill area bottom 11. The intermediate landfill area 14 is located on the bottom landfill area 13. The bottom landfill area 13 is used to landfill slag, and the intermediate landfill area 14 is used to landfill fly ash, hazardous waste containing heavy metals and other hazardous wastes. During the landfill operation, the bottom landfill area 13 within the landfill area 10 within a range of 1m from the bottom and slope of the landfill area 10 is only filled with slag to protect the anti-seepage unit 20 from damage, and fly ash, hazardous waste containing heavy metals and other hazardous wastes are buried in the intermediate landfill area 14 to delay the time when the leachate drainage system is blocked, which is also conducive to reducing the concentration of heavy metal ions and salts in the leachate and reducing the treatment cost.

[0066] A second embodiment of the present invention provides a hazardous waste landfill method, which is applied to the above-mentioned hazardous waste landfill system;

[0067] The hazardous waste landfill method comprises the following steps:

[0068] Divide the landfill unit into several landfill areas 10, lay an impermeable layer 21 on the slope 12 and the bottom of each landfill area, and lay an impermeable protective layer on the impermeable layer 21 to form an impermeable unit 20;

[0069] Several landfill areas 10 are arranged in sequence from high to low terrain. The edge of the landfill area 10 with the highest terrain is provided with an unloading platform 50 that meets the requirements of initial landfill operations. Hazardous waste is solidified and bagged to form hazardous waste ton bags. A crane 60 is used on the unloading platform 50 to lift the hazardous waste ton bags into the landfill area 10 at the end to form a temporary exit road connecting the unloading platform 50 to meet the subsequent transportation and landfill operations of the hazardous waste ton bags.

[0070] Specifically, the method for preparing the hazardous waste ton bag is as follows: adding a fixing agent, a stabilizer and water to the hazardous waste, stirring to form a hazardous waste solid body, and bagging the hazardous waste solid body to form a hazardous waste ton bag. The fixing agent is cement, lime or fly ash, and the stabilizer is sodium thiosulfate or a metal chelating agent.

[0071] A third embodiment of the present invention provides a hazardous waste landfill method, which is applied in the above-mentioned hazardous waste landfill system. The hazardous waste landfill method specifically includes the following steps:

[0072] The landfill unit is divided into a plurality of landfill areas 10, which are arranged in descending order according to the terrain. The edge of the landfill area 10 with the highest terrain is provided with a material unloading platform 50 that meets the requirements of the initial landfill operation, and an impermeable layer 21 is laid on the slope 12 and the bottom of each landfill area;

[0073] A first geotextile layer 221 and a bagged sand layer 222 are sequentially laid on the anti-seepage layer 21 of the landfill area slope 12 to form a first anti-seepage protective layer 22; a second geotextile layer 231, a geocomposite drainage net layer 232 and a geomat layer 233 are sequentially laid on the anti-seepage layer 21 of the landfill area bottom 11 to form a second anti-seepage protective layer 23; the first geotextile layer 221 and the second geotextile layer 231 are integrally connected;

[0074] Fixing the edges of the anti-seepage layer 21 and the first geotextile layer 221 on the anchoring platform 30;

[0075] After each of the landfill areas 10 is built, a temporary covering unit 40 is placed on the upper opening, and the edge of the temporary covering unit 40 is fixed to the anchoring platform 30 by weighting or using expansion screws;

[0076] Adding a fixative, a stabilizer and water to hazardous waste, wherein the fixative is cement, lime or fly ash, and the stabilizer is sodium thiosulfate or a metal chelating agent, and the weight ratio of the hazardous waste, the fixative, the stabilizer and the water is 3-5:1:0.02-0.04:0.5-0.7, and after stirring, a solid mixture is obtained to form a hazardous waste solid body, and the hazardous waste solid body is bagged to form a hazardous waste ton bag;

[0077] The temporary covering unit 40 is uncovered, and the hazardous waste ton bags are hoisted and placed on the unloading platform 50 by a crane 60 to the landfill area 10 with the highest terrain, forming a temporary road connecting the unloading platform 50 to meet the subsequent transportation and landfill operations of the hazardous waste ton bags. The order of landfilling is from high to low according to the terrain of the landfill area 10;

[0078] After the landfill is completed, the temporary covering unit 40 is used for covering.

[0079] A fourth embodiment of the present invention provides a hazardous waste landfill method, which is applied in the above-mentioned hazardous waste landfill system. The hazardous waste landfill method specifically comprises the following steps:

[0080] 1) Landfill layout:

[0081] According to the use time of the landfill and the terrain of the site, the landfill is divided into several landfill areas 10. The landfill area 10 for first burying hazardous waste is set as landfill area 1. Landfill area 1 is arranged in the highest area of ​​the landfill. Other landfill areas 10 are arranged in order from high to low according to the order of use and terrain, so that the leachate can seep out of the hazardous waste pile as soon as possible and gather at the lowest point, which is conducive to sewage diversion and improves the stability of the hazardous waste pile. Each landfill area 10 is provided with an anti-seepage unit 20 and an anchoring platform 30 that can meet the requirements of laying the anti-seepage unit 20. The width of the anchoring platform 30 is generally set to 4m to 6m to meet the requirements of mechanical operation as much as possible. An anchoring ditch is set at a distance of not less than 0.8m from the outside of the anchoring platform 30 and the anti-seepage unit 20 is anchored by backfilling with plain concrete to prevent slipping. The anti-seepage unit 20 includes an anti-seepage layer 21 with two layers of 2.0mm thick high-density polyethylene (HDPE) geomembrane, a first anti-seepage protective layer 22 and a second anti-seepage protective layer 23. After the construction of the anti-seepage unit 20, the integrity of the high-density polyethylene (HDPE) geomembrane should be tested to determine and repair the damage or weld problems caused during the construction process. The landfill area 1 is provided with a discharge platform 50 that can meet the initial landfill operation.

[0082] Specifically, the anti-seepage protection layer includes a second geotextile layer 231, a geocomposite drainage net layer 232, a geomat layer 233 laid on the bottom of the field, and a first geotextile layer 221 and a bagged sand layer 222 laid on the slope.

[0083] Specifically, the unloading platform 50 is arranged on the anchoring platform 30 arranged in the first landfill area, close to the initial landfill and located at a high position in the landfill area 10, with a width of 6m to 15m and a length of 10m to 20m, which can meet the operating requirements of the crane 60.

[0084] 2) Temporary covering facilities setting:

[0085] After the landfill area 10 is completed, a temporary covering unit 40 is set on top of the anti-seepage unit 20, which can be implemented simultaneously with the anti-seepage unit 20, and each block is overlapped at the anchoring platform 30. In order to prevent it from being blown away by the wind in the future, the slope and the bottom of the field are weighted with waste tires after the construction of the temporary covering unit 40, and the anchoring platform 30 is weighted with bagged soil or sand or fixed with expansion screws. The temporary covering unit 40 at the bottom of the field is directly covered with waste tires, and the waste tires weighed on the slope are tied in series with anti-aging materials, with a diameter requirement of not less than 10mm. The spacing of the weighted waste tires is 1m to 4m, and the spacing can be appropriately increased or decreased on site depending on whether it is a typhoon area. The materials used to tie the waste tires on the slope should be checked regularly, and if they are aged, they should be replaced in time.

[0086] Specifically, the temporary covering unit 40 uses a 0.75mm or 1.0mm thick high-density polyethylene (HDPE) smooth geomembrane. The temporary covering unit 40 is divided into several blocks. Each block is welded into a whole by a double-track hot-melt welding machine with different rolls of high-density polyethylene (HDPE) geomembrane. When laying, the blocks are overlapped from high to low along the water flow, and the overlap width is 1m to 2m. During the landfill process, the integrity of the temporary covering unit 40 should be checked manually and visually frequently, and if damaged, it should be replaced in time.

[0087] 3) Hazardous waste transportation:

[0088] According to the nature of hazardous waste, it is first stabilized and solidified in the stabilization and solidification workshop. After 5 to 10 days of curing, its compressive strength can reach 5kg / cm after 5 days of curing. 2 After 10 days of curing, its compressive strength can reach 10kg / cm 2 After passing the test, the stabilized and solidified hazardous waste will be packed in ton bags, and then the ton bags containing the stabilized and solidified hazardous waste will be transported to the landfill by dump trucks or forklifts.

[0089] Specifically, stabilization and solidification uses cement, lime (fly ash) and other curing agents, as well as sodium thiosulfate, metal chelating agents and other stabilizers and water according to the nature and composition of the hazardous waste. After mixing and curing with the hazardous waste, the loose hazardous waste with high water content is solidified into a stable, resistant to crushing and scattering solidified body. A single type of hazardous waste material should be mixed and stirred, and different hazardous wastes should be stirred at different times. Different types of hazardous waste materials should not be mixed and stirred at the same time. The solidified body is maintained in the stabilization and solidification workshop or landfill according to the incoming hazardous waste materials. If the incoming hazardous waste materials and the curing agent and stabilizer are treated and stabilized according to the ratio, the cured solidified body can be directly loaded into ton bags and transported to the landfill operation area for landfill. When the incoming materials or curing agents and stabilizers change, they must be tested again. Only after passing the test can they be transported to the landfill operation area for landfill treatment.

[0090] Specifically, the ton bag is made of geotextiles, which specifically include polyester fiber materials such as polypropylene and polyethylene. The weight of the ton bag filled with stabilized and solidified hazardous waste is between 0.5 tons and 1.5 tons, and the volume is between 500L and 1200L.

[0091] 4) Hazardous waste landfill:

[0092] According to the layout of the landfill, hazardous wastes are landfilled from the first landfill area, and a certain amount of stabilized and solidified hazardous wastes need to be accumulated and packed in ton bags. The tonnage of the crane 60 can be selected as 25 tons, 50 tons or 100 tons according to the horizontal distance and height between the bottom of the first landfill area and the unloading platform 50, and one ton bag is hoisted each time. The initial landfill is carried out on the unloading platform 50 by using the crane 60 to hoist and place the ton bags of stabilized and solidified hazardous wastes one by one from the bottom of the first landfill area until a temporary road is formed for the landfill machinery to drive and connect to the unloading platform 50. After the landfill machinery enters the site, the hazardous wastes are transported to the bottom of the landfill for paving and leveling. The landfill machinery can only be driven up to operate when the thickness of the hazardous wastes is filled to more than 1m. The subsequent landfill directly transports the ton bags of stabilized and solidified hazardous wastes to each landfill area 10 through the temporary road formed by the initial landfill, and then the landfill machinery is used for layered paving and rolling operations. During the landfill operation, only incineration slag is landfilled within a thickness of 1m at the bottom of the site and on the slopes. Other hazardous wastes such as fly ash and sludge containing heavy metals are landfilled in the middle area. Salt-containing wastes should be disposed of separately and necessary water-proofing and waterproofing treatment must be performed.

[0093] 5) Hazardous waste coverage:

[0094] In order to prevent rainwater from directly entering the hazardous waste pile, the landfilled hazardous waste is covered in a timely and comprehensive manner using a temporary covering unit 40, which is uncovered during the landfill operation and immediately covered after the landfill is completed each day, thereby reducing the amount of leachate generated from the source. During the pit filling operation, since the rainwater on the temporary covering unit 40 cannot flow out of the landfill by itself, a water collection pit is intentionally formed at the lowest point during the landfill operation, so that the rainwater can naturally flow into the water collection pit and then be pumped out of the landfill using a portable water pump.

[0095] In summary, the present invention provides a hazardous waste landfill method, which has the beneficial effects of: firstly stabilizing and solidifying the hazardous waste into a hazardous waste solid body and bagging it, and the compressive strength of the hazardous waste solid body reaches 5-10kg / cm 2 , which enables the organized transportation of hazardous waste materials and plays a reinforcing and stabilizing role on the hazardous material pile, can avoid secondary pollution during transportation, reduce the amount of leachate generated during landfill and delay the clogging time of the leachate collection system.

[0096] The initial landfill uses a crane 60 to lift hazardous waste ton bags containing hazardous waste solids on the unloading platform 50 to form a temporary landfill road, which can not only meet the subsequent transportation and landfill operation requirements of the hazardous waste solids, but also cancel the permanent landfill road and increase the landfill capacity. At the same time, the landfill is carried out in sections from high to low according to the terrain of the landfill area 10 and is temporarily covered in time, which solves the problem of sewage diversion in the hazardous waste landfill process, reduces the amount of leachate generated from the source, and reduces the landfill treatment cost and environmental pollution risk.

[0097] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the patent of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be subject to the attached claims.

Claims

1. A hazardous waste landfill method, characterized in that: The hazardous waste landfill method is applied to a hazardous waste landfill system, wherein the hazardous waste landfill system comprises a landfill unit, an anti-seepage unit and a discharge platform, wherein the landfill unit comprises a plurality of landfill areas, the anti-seepage unit is arranged on the landfill area, and the anti-seepage unit comprises an anti-seepage layer and an anti-seepage protective layer which are sequentially stacked from the inside to the outside; The hazardous waste landfill method specifically comprises the following steps: The landfill unit is divided into several landfill areas, which are arranged in order from high to low according to the terrain. The edge of the landfill area with the highest terrain is provided with a discharge platform that meets the requirements of the initial landfill operation. An impermeable layer is laid on the slope and the bottom of each landfill area. Among them, the landfill area where hazardous waste is buried first is set as the first landfill area, which is arranged in the highest terrain area of ​​the landfill site. The other landfill areas are arranged in order from high to low according to the order of use and terrain; A first geotextile layer and a bagged sand layer are sequentially laid on the anti-seepage layer of the landfill area slope to form a first anti-seepage protective layer, and a second geotextile layer, a geocomposite drainage net layer and a geomat layer are sequentially laid on the anti-seepage layer at the bottom of the landfill area to form a second anti-seepage protective layer, wherein the first geotextile layer and the second geotextile layer are integrally connected; Fixing the edges of the anti-seepage layer and the first geotextile layer on an anchoring platform; After each of the landfill areas is built, a temporary covering unit is placed on the upper opening, and the edge of the temporary covering unit is fixed to the anchoring platform by weight or expansion screws; The temporary covering unit is uncovered, and a crane is used to lift the hazardous waste ton bags onto the unloading platform and place them in the landfill area with the highest terrain to form a temporary road connecting the unloading platform to meet the subsequent transportation and landfill operations of the hazardous waste ton bags. The order of landfilling is from high to low according to the terrain of the landfill area; After the landfill is completed, the temporary covering unit is used for covering.

2. The hazardous waste landfill method according to claim 1, characterized in that: The preparation method of the hazardous waste ton bag is: adding a fixative, a stabilizer and water to the hazardous waste, stirring to form a hazardous waste solid body, and bagging the hazardous waste solid body to form a hazardous waste ton bag.

3. The hazardous waste landfill method according to claim 2, characterized in that: The fixing agent is cement, lime or fly ash, and the stabilizing agent is sodium thiosulfate or a metal chelating agent.

4. The hazardous waste landfill method according to claim 1, characterized in that: The hazardous waste landfill system further comprises an anchoring platform, the unloading platform is arranged on the anchoring platform, and the edges of the anti-seepage layer and the first geotextile layer are fixed on the anchoring platform.

5. The hazardous waste landfill method according to claim 1, characterized in that: The temporary covering unit is a high-density polyethylene geomembrane, and the thickness of the temporary covering unit is 0.75-1.0 mm.

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