Odor adsorption material, adsorption system and preparation method for landfill

Abstract

The present invention provides an odor adsorption material, adsorption system and preparation method for a landfill, which can efficiently absorb H2S in a landfill. An odor adsorption material for a landfill, the raw material of which is a recycled fine aggregate prepared from recycled construction waste and recycled powder mixed with recycled fine aggregate, and the recycled construction waste contains quicklime or slaked lime. An odor adsorption system for a landfill, the system includes at least one intermediate adsorption subsystem and a topmost closure adsorption subsystem; the intermediate adsorption subsystem includes three functional layers, which are, from top to bottom, an upper gas collection layer, an odor adsorption layer II, and a lower gas collection layer; the closure adsorption subsystem includes six functional layers, which are, from top to bottom, a vegetation layer, a drainage layer, an impermeable layer, a drainage layer, an odor adsorption layer I, and a gas collection layer I, and the materials of the odor adsorption layer I and the odor adsorption layer II are the odor adsorption materials.

Description

Technical Field

[0001] The invention relates to the technical field of garbage landfill, and in particular to an odor adsorption material, an adsorption system and a preparation method for a garbage landfill. Background Art

[0002] In recent years, with the sustained and rapid development of my country's national economy and the acceleration of urbanization, urban garbage has increased dramatically. As of 2012, the amount of domestic garbage collected and transported in China's cities was about 171 million tons. In addition to a small amount of incineration, composting and recycling, more than 60% was disposed of by sanitary landfill. Domestic garbage contains a large amount of organic matter, which will release a large amount of odorous substances during the landfill process. Among various odorous substances, hydrogen sulfide (H2S) is the most typical and common.

[0003] The H2S odor in landfills mainly comes from the oxidation of sulfur-containing organic matter and the reduction of sulfate under anaerobic conditions. In the early stage of landfill, the organic sulfur-containing components in the garbage (such as sulfur-containing vitamins or proteins, etc.) decompose under the action of microorganisms to produce H2S and accumulate a large amount of sulfate; in the middle and late stages, anaerobic microorganisms (mainly sulfate-reducing bacteria) use various organic matter or hydrocarbons to reduce sulfate, forming H2S under alienation, which is also the main source of H2S in landfills.

[0004] H2S has an irritating and suffocating smell of rotten eggs. Exposure to H2S can cause various eye, respiratory and neurological diseases, and even shock and death, which is very harmful to the health of workers and surrounding residents. In recent years, odor pollution outbreaks have frequently occurred in municipal landfills in Beijing, Shanghai, Guangzhou, Shenzhen and other cities, which have had a huge impact on the quality of life of surrounding residents and caused serious social problems. Therefore, effectively dealing with H2S odor pollution in landfills, reducing its damage to the surrounding ecological environment, and protecting people's health have become an important part of the comprehensive management of landfills.

[0005] The pollution control of H2S odor in landfills can be achieved by inhibiting the generation of H2S at the source and reducing the emission of H2S at the end.

[0006] Generally speaking, the conventional approach to inhibiting the generation of H2S from the source is: (1) inhibiting the activity of microorganisms in the system, mainly by adding alkaline substances such as sodium hydroxide and calcium hydroxide to increase the pH value, or adding fungicides; (2) inhibiting the activity of sulfate-reducing bacteria, mainly by injecting substances such as oxygen and nitrates to increase the redox potential. However, in practice, this approach is not very effective.

[0007] The terminal control of H2S odor is mainly carried out through the purification of H2S in landfill gas and the optimization of the cover layer to reduce H2S emissions and other terminal control measures.

[0008] Among them, landfill gas purification is mainly achieved through the gas drainage and collection system in the landfill, which collects and centrally purifies the landfill gas generated during the garbage degradation process. However, these technologies have high initial investment and operating costs, and many landfills in China lack a complete landfill gas drainage and collection system. Therefore, their actual application in large landfill areas is often limited.

[0009] Currently, the most commonly used method for controlling H2S odor in landfills is to use a landfill cover to achieve in-situ control of the odor.

[0010] The material selection of the landfill cover is directly related to the effect of in-situ odor control. Although the traditional clay cover technology is relatively mature, it has the disadvantages of poor deodorization effect, large storage capacity, precious and difficult to obtain clay resources, expensive materials, and affecting the migration of biogas and leachate. The ideal landfill cover material should generally have the following physical properties: high specific surface area, high moisture retention capacity, high mechanical strength, low bulk density, high porosity, high buffering capacity, easy to obtain, low cost, low transportation cost, long service life, etc. However, no one has found an ideal material that meets these characteristics. Therefore, it is urgent to find a more suitable landfill cover material.

[0011] The landfill cover layer is divided into the intermediate cover layer and the closure cover layer.

[0012] The intermediate cover refers to the temporary covering of exposed garbage during landfill operations due to processes such as spreading, leveling and compacting, as well as the migration of the working surface. The main functions of the intermediate cover include: (1) preventing the garbage from being exposed to a large amount of rainwater for a long time and generating a large amount of leachate; (2) inhibiting the release of odor into the atmosphere; and (3) reducing mosquitoes and flies and improving the adverse visual environment.

[0013] Among them, the main functions of the capping layer are anti-seepage and air-tightness. Anti-seepage means preventing rainfall, surface runoff and groundwater from infiltrating into the garbage body, thereby reducing the production of leachate. Air-tightness means reducing the leakage of landfill gas, including reducing the leakage of odor, thereby reducing the impact of the landfill on the surrounding environment and residents' lives.

[0014] At present, geocomposite materials (such as HDPE membranes) and clay and other anti-seepage materials are mainly used for intermediate covering and site sealing.

[0015] As a covering material, the main problems of geocomposites are high construction quality requirements, high engineering costs, and easy failure due to puncture by hard and sharp garbage components. In addition, HDPE membrane cannot absorb or process H2S, so a large amount of gas often accumulates under the membrane, causing bulging, which affects the service life of the membrane.

[0016] The advantages of the soil middle cover layer are that it is widely available, low cost, and stable, but the soil cover layer also has disadvantages such as low strength, which will weaken the stability of the garbage body, occupy storage capacity, consume soil resources, affect construction, and poor economy. In order to solve the above problems, "CN201810659898-Landfill Middle Cover Layer and Preparation Method and Application thereof" proposes to use recycled aggregates to construct the middle cover layer, in order to achieve the purpose of improving the mechanical properties of the garbage body through the reinforcement effect of recycled aggregates, and provide a certain degree of anti-seepage and air-tightness function. Its air-tightness function is to reduce the amount of odor passing through the low permeability layer.

[0017] However, both soil cover layers and cover layers constructed with recycled aggregates have several serious defects: (1) These cover layers are not intended to absorb or treat H2S, but only provide a barrier to isolate and prevent spillover; (2) Since H2S is not absorbed or treated, it will accumulate under the low permeability layer, and the gas pressure will increase over time, eventually breaking through the intake pressure value of the low permeability layer, forming a through channel, and then losing the air-locking function. Summary of the invention

[0018] In order to solve the above problems, the present invention provides an odor adsorption material, an adsorption system and a preparation method for a landfill, which can efficiently absorb H2S in the landfill.

[0019] The object of the present invention is achieved in the following manner: an odor adsorbing material for a landfill, the raw material of which is a recycled fine material prepared by mixing recycled fine aggregate and recycled powder prepared from recycled construction waste, and the recycled construction waste contains quicklime or slaked lime.

[0020] The proportion of concrete and mortar in the recycled construction waste for preparing recycled fine aggregate and recycled powder is ≥95%, the strength of the original concrete is not less than C30, and the particle size distribution curve of the odor adsorption material is saddle-shaped. Specifically, according to soil mechanics standards, the particle size distribution curve characteristics of the recycled fine material must meet the following conditions: (a) the maximum particle size does not exceed 2 mm; (b) the effective particle size d 10 Not more than 0.005mm; (c) 1.2mm≤d 90 ≤1.8mm; (d) Unevenness coefficient CU≥5; (e) Curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C ≥1.

[0021] There are many types of concrete, among which cement concrete is the most widely used and common. The concrete used in the preparation of odor adsorbent material or odor adsorbent layer material in the present invention specifically refers to cement concrete, that is, concrete prepared from various types of cement as cementitious materials. It must contain cement, and the general raw materials of cement contain silicate cement clinker, and silicate cement clinker contains calcium oxide, such as silicate cement, ordinary silicate cement, slag silicate cement, pozzolanic silicate cement, fly ash silicate cement, composite silicate cement, medium heat silicate cement, low heat slag silicate cement, fast hardening silicate cement, sulfate-resistant silicate cement, white silicate cement, road silicate cement, masonry cement, oil well cement, and gypsum slag cement.

[0022] The recycled construction waste contains quicklime or slaked lime. The odor adsorption mechanism of the odor adsorption material is to use the recycled fine material of construction waste as the odor adsorption layer material. The unreacted quicklime (CaO) or slaked lime (Ca(OH)2) and other alkaline substances in the construction waste react with the acidic substances (mainly H2S) in the odor to produce an acid-base neutralization reaction. The chemical reaction equation is as follows:

[0023]

[0024] In order for the above chemical reaction to occur and develop, some environmental conditions are required, such as a large specific surface area to increase the reaction contact area, a humid environment, etc. Therefore, in the present invention, the theoretical adsorption capacity is controlled by controlling the material properties, particle size distribution, adsorption layer thickness, etc. of the odor adsorbent material, and the contact area between the odor and the adsorbent material, the moisture content of the odor adsorbent material, the odor passing amount, the odor passing rate, the odor passing time (which can be regarded as the odor adsorption reaction time), etc. are controlled by controlling the compaction degree, the fine particle ratio, etc., thereby controlling the adsorption effect.

[0025] An odor adsorption system for a landfill, the system comprising at least one intermediate adsorption subsystem and a topmost closure adsorption subsystem; the intermediate adsorption subsystem is laid as a temporary cover and temporary adsorption after each landfill operation is completed, and is sandwiched inside the garbage body after the next landfill operation, and the closure adsorption subsystem is laid after the landfill operation is completed, and finally forms a composite structure of "garbage body-intermediate adsorption subsystem...-garbage body-closure adsorption subsystem" staggered and superimposed, that is, the upper and lower parts of the intermediate adsorption subsystem are garbage landfills, respectively. The garbage body after the operation is completed; the intermediate adsorption subsystem includes three functional layers, which are the upper gas collection layer, the odor adsorption layer II, and the lower gas collection layer from top to bottom; the closure adsorption subsystem includes six functional layers, which are: vegetation layer, drainage layer, anti-seepage layer, drainage layer, odor adsorption layer I, and gas collection layer I from top to bottom; the material of odor adsorption layer I and odor adsorption layer II is the odor adsorption material, the compaction degree of odor adsorption layer I and odor adsorption layer II is ≥95% respectively, and the permeability coefficient of odor adsorption layer I, odor adsorption layer I and odor adsorption layer II is 10 -6 m / s—10 -8 m / s, the air intake values ​​are 1kPa-10kPa, the water absorption rates are ≥10%, and the pore water saturations are 60%-90%.

[0026] The recycled coarse aggregate used in the upper and lower gas collection layers of the intermediate adsorption subsystem is recycled coarse aggregate prepared by recycling construction waste buried in landfills, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compacted relative density ≥0.9; the odor adsorption layer of the intermediate adsorption subsystem uses the above-mentioned odor adsorption material with a thickness of 0.3-0.6m.

[0027] The closure adsorption subsystem includes six functional layers, from top to bottom: vegetation layer, drainage layer, anti-seepage layer, drainage layer, odor adsorption layer I, and gas collection layer I. The vegetation layer uses natural soil plus surface nutrient soil to meet the nutritional needs of plant growth, and the thickness of the vegetation layer meets the root system needs of the planted vegetation. The thickness of the vegetation layer is ≥0.5m. The soil of the vegetation layer should be compacted in layers, and the compaction degree should not be less than 80%; the raw material of the drainage layer is recycled coarse aggregate prepared by recycling construction waste buried in the landfill, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compaction relative density of ≥0.9; the raw material of the anti-seepage layer is recycled fine aggregate prepared by recycling construction waste buried in the landfill. The maximum particle size of the recycled fine aggregate used is 2mm, and the effective particle size d of the particle size grading curve is 0.2-0.4m. 10 Not more than 0.01mm, unevenness coefficient C U ≥5, curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C≥1, compaction degree not less than 95%, permeability coefficient between 10 -9 m / s -10 -6 m / s, water absorption rate ≥8%, unsaturated soil mechanical air intake value ≥5kPa; the raw material of the drainage layer is recycled coarse aggregate prepared by recycling construction waste buried in landfill sites; the drainage layer thickness is 0.2-0.4m, the particle size is 10-40mm, the compacted relative density is ≥0.9, and the unsaturated soil mechanical air intake value does not exceed 1 kPa; the difference in air intake value between the recycled fine aggregate of the anti-seepage layer and the recycled coarse aggregate of the drainage layer is ≥4kPa; the odor adsorption layer I adopts the above-mentioned odor adsorption material, with a thickness of 0.4-1.0m; the gas collection layer I is located between the odor adsorption layer I and the garbage body, constructed with recycled coarse aggregate, with a thickness of 0.3-0.5m, a particle size of 20-40mm, and a compacted relative density of not less than 0.9.

[0028] The landfill odor adsorption system has water-permeable and air-permeable insulating material layers between each layer to prevent the raw materials of each layer from mixing.

[0029] The H2S odor adsorption method of the landfill odor adsorption system is mainly achieved through a combined adsorption system composed of several intermediate adsorption subsystems constructed during landfilling for layer-by-layer adsorption and a sealing adsorption subsystem for final adsorption; wherein the intermediate adsorption subsystem performs temporary odor adsorption as a temporary cover during landfill intervals, and can continue to adsorb odor as an intermediate layer of the garbage body after sealing; the odor adsorption in the sealing adsorption subsystem is mainly achieved through gas collection in gas collection layer I, adsorption in odor adsorption layer I, gas collection in drainage layer and adsorption in anti-seepage layer, with adsorption in odor adsorption layer I as the main method and adsorption in anti-seepage layer as the auxiliary method.

[0030] The landfill odor adsorption system has an anti-seepage function achieved by a double capillary barrier covering layer consisting of a first capillary barrier covering layer formed by an anti-seepage layer and a drainage layer and a second capillary barrier covering layer formed by an odor adsorption layer I and a gas collection layer I. The anti-seepage function of the first capillary barrier covering layer is primary, while the second capillary barrier covering layer is secondary.

[0031] In the odor adsorption system of the garbage landfill, a gas collecting layer exhaust device is provided on the side of the gas collecting layer I.

[0032] The recycled coarse aggregate, recycled fine aggregate and recycled powder required for the odor adsorption system of the landfill are all prepared by recycling construction waste. The construction waste also specifically refers to waste concrete construction waste. The strength of the original concrete of the construction waste used to prepare the odor adsorption layer material is not less than C30, and the strength of the original concrete of the materials of other layers except the vegetation layer is not less than C10. The recycled fine material refers to a mixture prepared by mixing recycled fine aggregate and recycled powder in a certain proportion, and the parameter performance requirements are as described above.

[0033] The method for preparing the landfill odor adsorption system comprises the following steps: (1) preparing materials according to the raw material requirements of each functional layer; before preparing the recycled aggregate and recycled powder, impurities such as wood, steel bars, and slag in the construction waste should be removed by pretreatment, leaving only waste concrete and mortar stone; (2) laying each functional layer according to the requirements of each layer.

[0034] Specifically, the preparation method of the landfill odor adsorption system comprises the following steps: (1) preparing materials according to the raw material requirements of each functional layer, the soil material of the vegetation layer can be obtained nearby, and the recycled materials required for other functional layers are obtained from the construction waste buried in the landfill or the construction waste to be buried in the landfill; before preparing the recycled aggregate and recycled powder, the impurities such as wood, steel bars, and slag in the construction waste are removed, and only the waste concrete and mortar stone are retained; then crushing, grinding and screening are performed to prepare the recycled coarse aggregate and recycled fine aggregate with the corresponding predetermined particle size requirements, and the micro powder, i.e., recycled powder, can be prepared by a dust collection device, and the micro powder and the recycled fine aggregate are mixed together to prepare the odor adsorption material;

[0035] (2) Before constructing the enclosure adsorption subsystem and the intermediate adsorption subsystem, the required materials need to be mixed with water to reach the optimal moisture content, and then sealed and cured to ensure uniform moisture content;

[0036] (3) Laying of the intermediate adsorption subsystem: After the landfill operation is completed, the landfill is leveled and rolled, and then a layer of geotextile is laid. Then, the compacted coarse aggregate of the lower gas collection layer is laid on the geotextile. The recycled coarse aggregate is laid in layers and fully compacted. The thickness of each layer shall not exceed 10 cm, and the compaction degree shall meet the requirements, not less than 0.9 relative density, and then the geotextile is laid; then, the odor adsorption layer II is laid on the geotextile. When laying, it shall be laid in layers and fully compacted. The thickness of each layer shall not exceed 10 cm, and the compaction degree shall not be less than 95%. After the laying of the attached layer II is completed, the odor adsorption layer II needs to be artificially watered or aired so that its moisture content reaches the predetermined adsorption reaction moisture content. When the next round of garbage landfill operation is carried out, it is only necessary to lay the upper gas collection layer on the odor adsorption layer. The laying method is the same as the lower gas collection layer. First lay the geotextile, then lay the upper gas collection layer on the geotextile, and then landfill the garbage; after the next round of garbage landfill operation is completed, continue to lay the intermediate adsorption subsystem, and then carry out the next round of landfill operation until the predetermined landfill elevation is reached for sealing, and lay the sealing adsorption subsystem;

[0037] (4) Laying of the closure adsorption subsystem: After the landfill operation is completed, the landfill is cleaned, leveled and rolled, and then a geotextile is laid on the compacted and leveled garbage body. Then, the compacted coarse aggregate of the gas collection layer I is laid on the geotextile. The recycled coarse aggregate is laid in layers and fully compacted. The thickness of each layer is not more than 10 cm, and the compaction degree meets the requirements. Then, the geotextile is laid, and then the odor adsorption layer I is laid on the geotextile. When laying, it needs to be laid in layers and fully compacted. The thickness of each layer is 10 cm, and the compaction degree is not less than 95%. After the odor adsorption layer I is laid, it needs to be manually watered or dried so that its moisture content reaches The predetermined adsorption reaction moisture content is achieved, and then the geotextile is laid, and the drainage layer is laid on the geotextile, and then the geotextile is laid, and the anti-seepage layer is laid on the geotextile. The laying needs to be layered and fully compacted, and the thickness of each layer shall not exceed 10cm. The compaction degree shall not be less than 95%, and then the geotextile is laid, and the drainage layer is laid on the geotextile, and then the geotextile is laid on the drainage layer, and then the vegetation layer is laid. After the laying of the closure adsorption subsystem is completed, monitoring and maintenance are required, especially the integrity and integrity of the adsorption system, the generation and distribution of landfill gas (especially H2S), and the operation of the odor adsorption function of the closure adsorption subsystem.

[0038] The odor adsorbing layer of the present invention refers to the odor adsorbing layer I and the odor adsorbing layer II.

[0039] It should be noted that in the production process of recycled aggregate at home and abroad, recycled coarse aggregate and recycled fine aggregate can be prepared by crushing and grading, and micro powder (particle size can be less than 0.15mm) can be collected by dust collection equipment to prepare recycled powder. Since the recycled fine materials for the anti-seepage layer and the odor adsorption layer in the present invention have high requirements for their micro powder ratio, the particle size gradation is between the traditional recycled fine aggregate and recycled powder. Therefore, in the present invention, the recycled material required for the anti-seepage layer is named as recycled fine aggregate, and the material required for the odor adsorption layer is named as recycled fine aggregate. It should be noted that this naming and particle size requirements are limited to the present invention patent. Since the particle size of the recycled fine material is different from that of traditional recycled coarse aggregate, recycled fine aggregate and recycled powder, therefore, in the actual industrial production process, the recycled fine material required by the present invention can be obtained by fully crushing and screening the waste concrete to reach the predetermined particle size, or by adding a certain proportion of recycled powder and mixing evenly to prepare recycled fine aggregate that meets the particle size requirements. In the present invention, no requirements are made on the preparation process of the recycled fine material, recycled coarse aggregate, recycled fine aggregate and recycled powder, and only requirements are made on parameters such as material properties and particle size.

[0040] The present invention provides an odor adsorption material, adsorption system and preparation method for a landfill, which controls the theoretical adsorption capacity by controlling the material properties, particle size distribution, adsorption layer thickness and the like of the odor adsorption layer, and controls the contact area between the odor and the adsorption material, the moisture content of the odor adsorption layer, the odor flow rate, the odor flow rate, the odor flow time (i.e., the odor adsorption reaction time) and the like by controlling the compaction degree and the ratio of different particle sizes of the recycled aggregate, thereby controlling the adsorption effect. The odor adsorption layer I prevents the odor from seeping out, and the gas collection layer I collects gas, thereby increasing the adsorption effect of the odor adsorption layer I. Furthermore, the adsorption effect of the odor adsorption layer I is further increased by the water storage, anti-seepage, moisture retention, gas collection and odor adsorption functions of the gas collection layer I and the drainage layer. The intermediate adsorption subsystem plays a temporary role in odor adsorption on the one hand, and can continue to adsorb odor as an intermediate interlayer of the garbage body after the site is sealed.

[0041] The main features of the odor adsorbent material in this patent include the following aspects:

[0042] (1) Large specific surface area. As is known to all, odor adsorption reaction mainly occurs on the surface of adsorption material. Increasing the specific surface area of ​​adsorption material can increase its contact area with H2S gas, thereby increasing odor adsorption chemical reaction and increasing odor adsorption. One of the main reasons for using construction waste recycled fine material as odor adsorption material proposed in the present invention is that the recycled fine material particles are relatively fine, which can significantly increase the surface area. At the same time, recycled fine material is also a typical porous material, and its pores mainly include primary pores and regenerated pores. Its pore volume is much larger than that of natural aggregate and soil with the same particle size distribution. Among them, primary pores are mainly primary pores on the mortar surface caused by foaming and other reasons during the preparation of concrete, and regenerated pores refer to new cracks or pores generated during the crushing preparation of recycled fine material. The increase of pores and cracks can greatly increase the specific surface area of ​​recycled aggregate, increase the contact area between the odor adsorption layer and H2S, and further improve the odor adsorption capacity.

[0043] (2) More fine particles and stronger adsorption capacity. The odor adsorption material proposed by the present invention has adsorption capacity mainly for cement, and the sand and gravel in the original concrete have no adsorption capacity. The cement mortar content in the fine particles of the recycled aggregate is relatively high, so increasing the proportion of fine particles can effectively increase the odor adsorption capacity of the recycled aggregate.

[0044] (3) The small permeability coefficient can effectively control the amount and time of odor passing through the odor adsorption layer. By reducing the amount of odor passing between units and extending the time of passing, the adsorption effect can be improved.

[0045] (4) The alkaline environment provided by the odor adsorption layer can effectively inhibit the generation of odor. According to literature reports, the pH value of compacted recycled aggregates is generally higher than 9, which exceeds the suitable pH environment for aerobic / anaerobic microorganisms that degrade garbage, and can effectively inhibit the generation of H2S.

[0046] (5) High water absorption and good water holding capacity. Studies have shown that in an environment with a high water content, the adsorption reaction between fine aggregates recycled from construction waste and H2S will be accelerated, and odor can be better adsorbed. Generally speaking, the water content of recycled aggregates is 15 times that of natural aggregates, and the water absorption rate is 10.2 times that of natural aggregates. This is mainly because the porosity of recycled aggregates is large. The pores in recycled aggregates include pores between particles and pores inside aggregate particles. Therefore, in the compacted recycled aggregate layer, water can be stored in the pores between aggregate particles and in the pores inside the particles. In addition, the cement mortar attached to the surface of the recycled aggregate has good hydrophilicity. According to the basic theory of unsaturated soil mechanics, compacted recycled aggregates have good water holding capacity and can absorb and retain water more easily.

[0047] (6) High strength. The intermediate adsorption subsystem needs to have good mechanical properties so that it can form a reinforcement effect between different layers of garbage to improve the mechanical stability of the entire garbage body. According to literature reports, the mechanical strength of compacted recycled aggregate is much greater than that of natural soil or gravel with the same particle size distribution. Using recycled aggregate as the material of the intermediate adsorption subsystem can greatly improve the mechanical properties of the intermediate adsorption subsystem and further improve the stability of the garbage body.

[0048] (7) Low cost and easy to obtain. There are many technologies and materials for odor adsorption, but the cost is generally high and requires large-scale long-distance transportation, which results in low economic efficiency. Therefore, odor adsorption materials should be low-cost and easy to obtain.

[0049] Compared with the prior art, the present invention provides the following beneficial effects:

[0050] (1) The concept of "using garbage to absorb garbage odor" is proposed to achieve the recycling of construction waste, energy saving and emission reduction, and green environmental protection. The present invention creatively proposes to use construction waste buried in landfills to absorb the odor generated by landfill garbage, thus achieving the recycling of construction waste, energy saving and emission reduction, and green environmental protection.

[0051] (2) Provide an odor adsorption system that uses H2S absorption treatment as a means to achieve odor control. The present invention provides an odor adsorption system that achieves odor adsorption by adsorption, which includes several intermediate adsorption subsystems and a closure adsorption subsystem. The intermediate adsorption subsystem can be used as a temporary odor adsorption after a single landfill operation is completed, and can also be used as an intermediate layer of the garbage body after closure to continue odor adsorption.

[0052] (3) It can effectively inhibit the generation of H2S. The odor adsorption layer and gas collection layer of the odor adsorption system provided by the present invention are made of recycled aggregates from construction waste. According to literature reports, the pH value of compacted recycled aggregates is generally higher than 9, which exceeds the suitable pH environment for aerobic / anaerobic microorganisms that degrade waste, and can effectively inhibit the generation of H2S.

[0053] (4) Improve the permeability of the garbage body, improve the gas collection and extraction capacity, accelerate the degradation of the garbage body, and improve the odor adsorption effect. The intermediate adsorption subsystem in the odor adsorption system provided by the present invention contains upper and lower gas collection layers constructed of highly permeable recycled coarse aggregate. As the landfill operation proceeds, a layer of garbage is superimposed on an intermediate adsorption subsystem to form a composite structure with multiple good permeability and gas collection functions. This composite structure can greatly improve the permeability of the garbage body and enhance the gas collection and extraction capacity during the later maintenance process. In conjunction with engineering measures such as ventilation and exhaust, it can accelerate the degradation of the garbage body and accelerate the extraction capacity of methane (CH4) generated by the degradation of the garbage body. In addition, the improvement of the permeability of the garbage body is also conducive to the entry of H2S into the upper and lower gas collection layers and the odor adsorption layer II. In conjunction with engineering means, the air pressure of the upper and lower gas collection layers can be controlled to maintain it at the pressure required for the optimal odor adsorption reaction, thereby promoting the adsorption effect of H2S gas. There is also a gas collection layer I in the closure adsorption subsystem, which can also provide similar effects.

[0054] (5) Improve the moisture retention capacity of the adsorption system, so that the garbage body and the odor adsorption layer in the adsorption system maintain appropriate humidity, thereby creating a suitable environment for the H2S adsorption reaction and accelerating the H2S adsorption reaction. The odor adsorption system in the odor adsorption system of the present invention uses a double capillary barrier system composed of an impermeable layer and a drainage layer, an odor adsorption layer I and an air collection layer I to prevent seepage, seal air and retain moisture. Under the action of the double capillary barrier system, rainwater cannot penetrate into the closure adsorption subsystem and the garbage body; at the same time, the moisture in the closure adsorption subsystem and the garbage body will not evaporate into the air, thereby ensuring the stability of the moisture content in the closure adsorption subsystem and the garbage body. In the actual working process, the moisture content of the landfill garbage will be pretreated before laying the odor adsorption layer I, and the coarse and fine recycled aggregates of the air collection layer I and the odor adsorption layer I will also be pretreated to ensure that the moisture content of the garbage body and the air collection layer I and the odor adsorption layer I reaches a predetermined value. This pretreatment method includes watering, stirring, drying, exposure to the sun, air drying, etc. For the closure adsorption subsystem for odor adsorption treatment, the predetermined moisture content of the garbage body, gas collection layer I and odor adsorption layer I depends on the progress of the odor adsorption reaction.

[0055] (6) Using construction waste from landfills to absorb H2S, local materials are used, and there is no need to transport a large amount of odor adsorption materials from outside. This avoids the disadvantage that traditional odor adsorption materials and the soil cover layer constructed consume the storage capacity of the landfill. The H2S absorption treatment method involved in the present invention does not require the additional transportation of a large amount of soil and odor adsorption materials from outside. It only needs to use local materials and recycle the construction waste buried in the landfill. Therefore, the odor adsorption system for odor adsorption treatment involved in the present invention does not require the transportation of a large amount of odor adsorption materials from outside; at the same time, it avoids the disadvantage that the traditional soil cover layer requires a large amount of engineering materials to be transported from outside, and the disadvantage that the traditional soil cover layer is too thick, resulting in serious consumption of landfill storage capacity.

[0056] (7) More reasonable arrangement of the landfill garbage body shape and landfill construction process, increase the landfill storage capacity, and maximize the odor adsorption effect. The landfill garbage body is restricted by mechanical properties, and its height, slope, single landfill layer thickness and other morphological parameters are restricted. The odor adsorption system of the present invention is constructed with high-strength recycled aggregates, and the implementation of the present invention makes the structure after the landfill is closed into "garbage body-intermediate adsorption subsystem-garbage body-intermediate adsorption subsystem-...-garbage body-sealing adsorption subsystem". This garbage body formed by the staggered superposition of the composite structure of "garbage body-intermediate adsorption subsystem" will play a mechanical reinforcement role due to the high mechanical strength of the intermediate adsorption subsystem, thereby improving the mechanical properties and mechanical stability of the garbage body. Therefore, the implementation of the present invention eliminates the above-mentioned restrictive factors, so that the landfill garbage body shape can be arranged more reasonably, the landfill garbage body can be higher and the slope can be larger, thereby increasing the storage capacity of the landfill. On the other hand, by consuming the construction waste in the landfill, the storage capacity occupied by the construction waste can also be released, thereby increasing the storage capacity of the landfill from another angle. In addition, due to the absence of other limiting factors, the design concept of the landfill construction process of the garbage body will focus on maximizing odor adsorption, reasonably setting the thickness of the single landfill layer and the thickness of the intermediate adsorption subsystem layer, and reasonably setting the landfill operation process.

[0057] (8) Consume a large amount of construction waste in landfills and release the storage capacity occupied by construction waste. In traditional landfills, construction waste occupies a large amount of storage capacity. The odor adsorption system involved in the present invention uses recycled materials prepared by recycling construction waste from landfills, and the recycled aggregates made from construction waste are used in the odor adsorption system. The excess recycled aggregates can also be exported for use in other civil engineering projects. In this way, construction waste can be effectively consumed and utilized, thereby releasing the storage capacity occupied by construction waste in landfills and improving the economic and social benefits of landfills.

[0058] (9) Convenient material acquisition, low cost, good durability, simple and low cost for later maintenance. The odor adsorption system involved in the present invention is mainly made of construction waste in landfills, which avoids the need for traditional soil cover layers to transport a large amount of soil resources from outside and the high material and transportation costs. In addition, the material stability and durability of recycled aggregates are good, the adsorption system has a stable structure, simple maintenance, and low maintenance costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0059] Figure 1 It is a structural schematic diagram of the landfill odor adsorption system of the present invention.

[0060] Figure 2 It is a structural diagram of the sealing adsorption subsystem.

[0061] Figure 3 It is a schematic diagram of the structure of the intermediate adsorption subsystem.

[0062] Figure 4 It is the typical particle grading curve of each functional layer.

[0063] Figure 5 It is a schematic diagram of the adsorption principle of odor in the sealing adsorption subsystem.

[0064] Figure 6 It is a schematic diagram of the adsorption principle of odor in the intermediate adsorption subsystem.

[0065] Figure 7 It is a schematic diagram of the anti-seepage and air-tightening principle of the sealing adsorption subsystem.

[0066] Diagram: 1. Vegetation; 2. Vegetation layer; 3. Drainage layer; 4. Anti-seepage layer; 5. Drainage layer; 6. Odor adsorption layer I; 7. Gas collection layer I; 8. Garbage body; 9. Water-permeable and breathable insulation material layer; 10. Upper gas collection layer; 11. Odor adsorption layer II; 12. Lower gas collection layer; 13 Drainage layer exhaust device; 14. Gas collection layer I exhaust device; 15. Upper gas collection layer exhaust device; 16. Lower gas collection layer exhaust device; 17 Anti-seepage lining layer; 18 Sealing adsorption subsystem; 19 Intermediate adsorption subsystem; 20 Rainfall; 21 Slope runoff; 22 Lateral drainage of drainage layer; 23 Lateral drainage of drainage layer.

[0067] Note: In this implementation, the drainage layer, the drainage layer, the gas collection layer I, and the upper and lower gas collection layers of the intermediate adsorption subsystem all use recycled coarse aggregates of the same particle size. Figure 4 In this embodiment, the odor adsorption layer I of the enclosure adsorption subsystem and the odor adsorption layer II of the intermediate adsorption subsystem are made of the same material. Figure 4 The particle size curves of the two overlap. DETAILED DESCRIPTION

[0068] The present invention will be described in detail below in conjunction with the accompanying drawings and specific implementation methods. It is necessary to point out here that the schematic embodiments and descriptions of the present invention are only used to further explain the present invention and cannot be understood as limiting the scope of protection of the present invention. Technical personnel skilled in the art can make some non-essential improvements and adjustments based on the contents of the present invention.

[0069] like Figure 1-Figure 7 As shown, an odor adsorption material for a landfill, the raw material is recycled fine material, the recycled fine material is a mixture of recycled fine aggregate and recycled powder prepared from recycled construction waste, the proportion of concrete and mortar in the construction waste for preparing recycled fine aggregate and recycled powder is ≥95%, and the particle size distribution curve of the odor adsorption layer presents a saddle shape. Specifically, according to soil mechanics standards, the particle size gradation curve characteristics of the recycled fine material must meet the following conditions: (a) the maximum particle size does not exceed 2 mm; (b) the effective particle size d 10 Not more than 0.005mm; (c) 1.2mm≤d 90 ≤1.8mm; (d) Unevenness coefficient CU≥5; (e) Curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C ≥1, compaction degree ≥95%, the air permeability coefficient of the odor adsorbent material at the maximum dry density is 10 -6 m / s—10 -8 m / s, air intake value 1kPa-10kPa, water absorption rate ≥10%, pore water saturation 60%-90%. For example, the odor adsorption material here is mainly used to construct the odor adsorption layer Ⅰ6 or the odor adsorption layer Ⅱ11.

[0070] A landfill odor adsorption system is composed of a landfill closure adsorption subsystem 18 and at least one intermediate adsorption subsystem 19. The landfill closure adsorption subsystem 18 includes six functional layers, which are, from top to bottom: vegetation layer 2, drainage layer 3, impermeable layer 4, drainage layer 5, odor adsorption layer I6, gas collection layer I7, and below the gas collection layer I7 is the garbage body. The landfill intermediate adsorption subsystem 19 includes three functional layers, which are, from top to bottom: upper gas collection layer 10, odor adsorption layer II, lower gas collection layer 12, and below the gas collection layer 12 is the garbage body.

[0071] The requirements for the functional materials of the closure adsorption subsystem 18 are as follows: the soil of the vegetation layer 2 must meet the relevant requirements of the soil of the vegetation layer of the landfill, and the present invention does not impose additional restrictions. For example, the vegetation layer 2 is prepared by natural soil plus surface nutrient soil, or soil around the landfill can be used. The five functional layers of the drainage layer 3, the impermeable layer 4, the drainage layer 5, the odor adsorption layer Ⅰ6 and the gas collection layer Ⅰ7 are all constructed by recycled materials prepared by recycling construction waste buried in the landfill, preferably using discarded high-strength concrete. It is required that the strength of the original concrete of the drainage layer 3, the impermeable layer 4, the drainage layer 5 and the gas collection layer Ⅰ7 is not less than C10, and the strength of the original concrete of the odor adsorption layer Ⅰ material is not less than C30; and before preparing the recycled aggregate from the construction waste, impurities (including slag, steel bars, wood, glass, plastic, bricks, paper, fabrics, etc.) are removed, and only concrete and mortar blocks are retained, and the weight of concrete and mortar accounts for not less than 95%.

[0072] The closure adsorption subsystem 18, the vegetation layer 2 uses natural soil plus surface nutrient soil or soil from the surrounding area of ​​the landfill, and its thickness should be determined according to the depth of the plant roots, and the thickness should not be less than 0.5m. The vegetation layer soil should be compacted in layers, and the compaction degree should not be less than 80%. The vegetation layer is preferably planted with turf with shallow roots, and the fertilization, irrigation, and tillage construction methods of the vegetation layer soil are determined according to the characteristics of the planted plants. The main function of the vegetation layer is to beautify the greening, prevent soil and water loss, and release the water that has infiltrated and stored in the vegetation layer into the atmosphere through surface evaporation and plant transpiration during non-rainfall time, so as to maintain the water balance of the closure adsorption subsystem. It should be noted that the main function of the vegetation layer in the present invention is as described above, and it does not bear the functions of anti-seepage, air-tightness, and odor adsorption. Therefore, the main considerations for the parameter design of the vegetation layer 2 are that the materials are obtained nearby, the soil nutrition is sufficient to support the growth of the landfill vegetation 1, and the material cost is low.

[0073] The drainage layer 3 of the closure adsorption subsystem 18 is located below the vegetation layer 2 and above the anti-seepage layer 4, and is constructed of recycled coarse aggregate prepared by recycling construction waste buried in the landfill site, with a thickness of 0.2-0.4m, a particle size of 20-40mm, a compacted relative density of not less than 0.9, and a permeability coefficient of not less than 10 -1m / s. The main function of the drainage layer is to drain away the water that infiltrates into the drainage layer and serve as a support layer for the vegetation layer. Therefore, the main requirements for its parameter performance are that the mechanical strength is good enough to support the vegetation layer, the permeability is good so that the water that infiltrates the vegetation layer can be drained away as quickly as possible, and the material is easy to obtain, the material cost is low, and the durability is good. The parameter design of the drainage layer needs to consider factors such as the local maximum rainfall, the maximum infiltration of the vegetation layer, the slope, the permeability coefficient of the drainage layer and the thickness of the drainage layer in order to meet the maximum drainage needs. In addition, because the strength of the aggregate recycled from construction waste is far greater than the mechanical properties of natural soil, it can meet the mechanical strength requirements for supporting the vegetation layer.

[0074] The sealing adsorption subsystem 18, the anti-seepage layer 4 is located between the drainage layer 3 and the drainage layer 5, the raw material of the anti-seepage layer 4 is recycled fine aggregate prepared by recycling construction waste buried in the landfill site, the maximum particle size of the recycled fine aggregate used is 2mm, and the effective particle size d of the particle size grading curve is 10 Not more than 0.01mm, unevenness coefficient C U ≥5, curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C ≥1, compaction degree not less than 95%, permeability coefficient between 10 -9 m / s -10 -6 m / s, water absorption rate ≥8%, unsaturated soil mechanical air intake value ≥5kPa; the raw material of the drainage layer is recycled coarse aggregate prepared by recycling construction waste buried in landfills; the drainage layer thickness is 0.2-0.4m, the particle size is 10-40mm, the compacted relative density is ≥0.9, and the unsaturated soil mechanical air intake value exceeds 1 kPa; the difference in air intake value between the recycled fine aggregate of the anti-seepage layer and the recycled coarse aggregate of the drainage layer is ≥4kPa.

[0075] The functions of the anti-seepage layer 4 mainly include surface drainage, water storage, anti-seepage, moisture retention, gas collection and odor absorption. First, the compaction degree of the compacted recycled aggregate of the anti-seepage layer is controlled to be above 95%, and the permeability coefficient is not more than 10 -6m / s, plus the slope design of the closure adsorption subsystem (the slope of the present invention can be 30°-60°, preferably 40°-50°), it can effectively reduce rainwater infiltration and convert most of the rainwater into lateral drainage of the drainage layer 22. Secondly, the compacted recycled aggregate of the anti-seepage layer has good water storage and water holding capacity, which can absorb and store the infiltrated water to the maximum extent during rainfall. On the other hand, the difference in air intake value between the recycled fine aggregate of the anti-seepage layer and the recycled coarse aggregate of the drainage layer is more than 4KPa, forming a capillary blocking covering layer, forming a capillary blocking effect, which can effectively block the infiltrated water from entering the drainage layer. The moisturizing function of the anti-seepage layer means that the capillary blocking covering layer formed by the anti-seepage layer and the drainage layer can effectively protect the odor adsorption layer I below, prevent the odor adsorption layer I from evaporating and drying, which is conducive to the odor adsorption layer I maintaining a high water content for a long time, and the compacted recycled fine aggregate will accelerate the adsorption reaction with H2S in an environment with a high water content, which can better promote and ensure the odor adsorption reaction of the odor adsorption layer I. The gas collecting function of the anti-seepage layer means that when the odor (mainly H2S) fails to undergo an adsorption reaction in the odor adsorption layer I and instead breaks through the odor adsorption layer I to enter the drainage layer, the anti-seepage layer has a low permeability coefficient, which can effectively prevent the odor from further breaking through and overflowing upward, and accumulates the odor that breaks through the odor adsorption layer I in the drainage layer, forming a gas collecting effect, and maintaining a higher air pressure and a higher concentration of H2S gas in the drainage layer, which can accelerate the chemical reaction between the recycled aggregate in the odor adsorption layer I and the H2S gas, thereby accelerating the adsorption of H2S; in the case of gas extraction, it will also help to enrich the H2S gas in the gas collection layer I and the drainage layer, which has a favorable effect on odor adsorption. The odor adsorption function of the anti-seepage layer means that the construction material of the anti-seepage layer is recycled fine aggregate from construction waste, and there are unreacted quicklime (CaO) or slaked lime (Ca(OH)2) and other alkaline substances remaining inside, which can react with the odor (mainly H2S) that breaks through the odor adsorption layer I and overflows upward, thereby preventing the odor from further overflowing the sealing adsorption subsystem into the atmospheric environment and affecting the surrounding environment.

[0076] The described closure adsorption subsystem 18, the drainage layer 5 is located between the anti-seepage layer 4 and the odor adsorption layer I 6, and is constructed of recycled coarse aggregate prepared by recycling construction waste buried in landfill sites. The drainage layer has a thickness of 0.2-0.4m, a particle size of 10-40mm, preferably a particle size of 20-40mm, a compacted relative density of not less than 0.9, and an unsaturated soil mechanical air intake value of not more than 1KPa. The functions of the drainage layer are mainly anti-seepage, drainage and gas collection. Among them, the anti-seepage and drainage functions are to form a capillary barrier covering layer between the recycled coarse aggregate of the drainage layer and the recycled fine aggregate of the anti-seepage layer, preventing the infiltrated rainwater from further entering the drainage layer, the odor adsorption layer I and even the garbage body; after the infiltrated water breaks through the capillary barrier effect, the permeability coefficient of the drainage layer is relatively large (not less than 10 -2m / s), which can laterally guide and drain the water that infiltrates into the drainage layer. On the other hand, a highly permeable odor-enriched area is formed under the anti-seepage layer, which is convenient for collecting the gas (including H2S) that breaks through the odor adsorption layer I, providing certain gas collection and exhaust functions, and facilitating the control of higher pressure and higher concentration of H2S gas in the drainage layer, which can accelerate the chemical reaction between the recycled aggregate and H2S gas in the odor adsorption layer I, thereby accelerating the adsorption of H2S.

[0077] The raw material of the odor adsorption layer I6 is recycled fine material, which is made by mixing recycled fine aggregate and recycled powder prepared by recycling construction waste. Its parameters are as follows:

[0078] (1) Material requirements: Recycled aggregates need to be quality controlled. The recycled fine materials here include recycled fine aggregates and recycled powder. Recycled aggregates prepared from discarded high-strength concrete are preferred, and the strength of the original concrete is required to be no less than C30; and before preparing recycled aggregates from construction waste, impurities (including slag, steel bars, wood, glass, plastic, bricks, paper, fabrics, etc.) are removed, and only concrete and mortar blocks are retained. The weight of concrete and mortar accounts for no less than 95%, of which cement stone (and cement paste hardening body) and mortar content is no less than 40%. As the grade of the original concrete increases, the proportion of cement in the corresponding mix also increases, and the amount of alkaline substances such as quicklime (CaO) or slaked lime (Ca(OH)2) remaining in the original concrete will also increase, which is more conducive to improving the odor adsorption capacity.

[0079] (2) Layer thickness: 0.4-1.0m. It should be noted that the thickness of the odor adsorption layer I depends on the thickness of the landfill operation, the type of landfilled garbage, and the adsorption characteristics of the adsorbent material in the odor adsorption layer I. When the thickness of the landfill operation increases and the content of sulfur-containing organic waste that can be degraded to produce H2S increases, it means that the H2S generated by the landfill garbage will also increase, and the thickness of the corresponding odor adsorption layer I will also increase.

[0080] (3) The particle size distribution curve is saddle-shaped, that is, the fine and coarse particles account for a large proportion, and the intermediate particles are relatively small. Specifically, according to soil mechanics standards, the particle size distribution curve characteristics of recycled fine materials must meet the following conditions: (a) the maximum particle size does not exceed 2 mm; (b) the effective particle size d 10 Not more than 0.005mm; (c) 1.2mm≤d 90 ≤1.8mm; (d) Unevenness coefficient CU≥5; (e) Curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C≥1. The purpose of designing this particle size distribution is that the particle size distribution curve of the compacted fine aggregate layer presents a saddle shape, among which the coarse particles have a higher shear strength, forming the skeleton of the odor adsorption layer Ⅰ6 obtained after compaction, and improving the mechanical properties of the odor adsorption layer Ⅰ6 obtained after compaction. Fine particles are filled in the skeleton pores constructed by coarse particles, controlling the water holding capacity and air permeability coefficient of the odor adsorption layer Ⅰ6 obtained after compaction. A high proportion of fine particles can improve the water holding capacity of the odor adsorption layer Ⅰ6 obtained after compaction and reduce its air permeability coefficient.

[0081] (4) The compaction degree of the recycled fine material in the odor adsorption layer I is not less than 95%. Improving the compaction degree can improve its mechanical strength, compress the pore volume, and increase the water holding capacity; at the same thickness, increasing the compaction degree can use more recycled aggregates, which can increase the total amount of alkaline substances in the odor adsorption layer I and thus improve the adsorption capacity; on the other hand, it can also consume more construction waste and realize the recycling of construction waste.

[0082] (5) Requirements for the air permeability of the regenerated fine material of the odor adsorption layer I: The air permeability coefficient of the compacted regenerated fine material of the odor adsorption layer I at the maximum dry density is 10 -6 m / s—10 -8 m / s, air intake value 1kPa-10kPa. The purpose of selecting the permeability parameters is to control the time for odor to pass through the odor adsorption layer I, thereby controlling the amount of odor passing through and extending the odor adsorption reaction time of odor in the odor adsorption layer I, thereby improving the odor adsorption effect.

[0083] (6) Water absorption requirement: The water absorption of the odor adsorption layer I material shall not be less than 10%. The water absorption of the recycled aggregate depends on the pore volume and the hydrophilic properties of the material. Among them, the pores include the pores between the particles of the compacted odor adsorption layer I and the pores and cracks of the particles themselves. The pores between the particles depend on the shape, particle size and compaction degree of the particles. Generally speaking, the higher the cement stone (i.e., cement slurry hardening body) and mortar content of the recycled fine material, the greater the water absorption; the more microcracks in the fine aggregate, the greater the water absorption. The present invention requires that the proportion of concrete and mortar in the construction waste used to prepare the recycled fine material be not less than 95%, and accordingly, the water absorption requirement for the prepared recycled fine material is not less than 10%.

[0084] (7) Moisture content requirement: saturation 60%-90%. The present invention requires that the pore water saturation of the regenerated fine material is not less than 60%. This is because the H2S adsorption reaction is more suitable in a humid environment, and a higher moisture content can improve the efficiency of the adsorption reaction. However, in order to ensure the permeability of the odor adsorption layer I, the pore water saturation of the compacted regenerated fine material layer cannot be 100%, otherwise the regenerated fine material layer is completely saturated and its permeability coefficient will become 0. Through research, the present invention proposes that the maximum saturation should not be higher than 90%. In order to ensure a saturation of 60%-90%, it is required that the compacted regenerated fine material of the odor adsorption layer I contains enough fine particles (especially clay particles, i.e. <0.002mm) to improve the water holding capacity of the odor adsorption layer I. In addition, the maintenance of the moisture content in the compacted recycled aggregate of the odor adsorption layer I requires processes such as mixing water to configure the optimal moisture content before laying the regenerated fine material and sprinkling water to the predetermined moisture content after laying.

[0085] The main function of the odor adsorption layer I of the closure adsorption subsystem is to seal air and adsorb odor, and also to perform anti-seepage function. Its parameter design is also mainly to maximize the odor adsorption capacity and efficiency. The anti-seepage function of the odor adsorption layer I is mainly reflected in the fact that the particles of the odor adsorption layer I material are much smaller than the recycled coarse aggregate of the gas collection layer I. A capillary blocking effect will be formed between the two, preventing the water that has infiltrated into the odor adsorption layer I from further infiltrating into the gas collection layer I and the garbage body. However, the odor adsorption layer I is under the protection of the anti-seepage layer and the drainage layer, and its moisture content has been maintained at a high level for a long time. Therefore, the water storage capacity of the odor adsorption layer I is relatively weak. Therefore, the anti-seepage function of the odor adsorption layer I is mainly manifested in the capillary blocking effect between the odor adsorption layer I and the gas collection layer I. In addition, the adsorption material of the odor adsorption layer I has a low permeability coefficient, which can effectively prevent landfill gas from breaking through the odor adsorption layer I and entering the atmosphere.

[0086] The odor adsorption mechanism of the odor adsorption layer I is that the recycled aggregate of construction waste is used as the material of the odor adsorption layer. The unreacted quicklime (CaO) or slaked lime (Ca(OH)2) and other alkaline substances remain in the construction waste, which react with the acidic substances (mainly H2S) in the odor to produce an acid-base neutralization reaction. In order for the above chemical reaction to occur and develop, some environmental conditions are required, such as a large specific surface area to increase the reaction contact area, a humid environment, etc. In the present invention, the theoretical adsorption capacity is controlled by controlling the material properties, particle size grading, and adsorption layer thickness of the odor adsorption layer I, and the contact area between the odor and the adsorption material, the moisture content of the odor adsorption layer I, the odor passage amount, the odor passage rate, the odor passage time (i.e., the odor adsorption reaction time), etc. are controlled by controlling the compaction degree, the fine particle ratio, etc., thereby controlling the adsorption effect.

[0087] The anti-seepage function of the odor adsorption layer I is mainly reflected in the difference in particle size between the material of the odor adsorption layer I and the recycled coarse aggregate of the gas collection layer I. A capillary barrier effect will be formed between the two, preventing the moisture that has infiltrated into the odor adsorption layer I from further infiltrating into the gas collection layer I and the garbage body. However, the odor adsorption layer I is under the protection of the anti-seepage layer and the drainage layer, and its moisture content has been maintained at a high level for a long time. Therefore, the water storage capacity of the odor adsorption layer I is relatively weak. Therefore, the anti-seepage function of the odor adsorption layer I is mainly manifested in the capillary barrier effect between the odor adsorption layer I and the gas collection layer I. But in general, the anti-seepage function of the adsorption subsystem involved in the present invention is mainly achieved by the anti-seepage layer, and the anti-seepage function of the odor adsorption layer I serves as an auxiliary function.

[0088] The closure adsorption subsystem 18, the gas collection layer I is constructed of recycled coarse aggregate, with a thickness of 0.3-0.5m, a particle size of 20-40mm, and a compacted relative density of not less than 0.9. The function of the gas collection layer I is to be located between the odor adsorption layer I and the garbage body to facilitate the collection of odor, and to control the intensity of the H2S gas partial pressure in the gas collection layer I through the exhaust device, thereby controlling the partial pressure distribution of the H2S gas in the closure adsorption subsystem. When the odor generated by the degradation of the garbage body enters the closure adsorption subsystem, it is blocked by the odor adsorption layer I and the anti-seepage layer and is enriched in the closure adsorption subsystem. The particle size of the gas collection layer I is large, the pore volume is high, and a large amount of gas can be enriched; and the gas collection layer I has a large permeability coefficient, and the odor can be quickly extracted and discharged during the extraction, which is convenient for controlling the vertical distribution of the odor partial pressure in the adsorption subsystem. In addition, a capillary barrier effect can be formed between the recycled coarse aggregate of the gas collection layer I and the adsorption material of the odor adsorption layer, which can assist in providing an anti-seepage function and prevent the moisture that has infiltrated into the odor adsorption layer I from further infiltrating into the gas collection layer I and the garbage body.

[0089] The water storage of the compacted recycled fine aggregate layer of the anti-seepage layer 4 and the recycled fine aggregate layer of the odor adsorption layer I in the enclosure adsorption subsystem 18 is mainly achieved through macropore accommodation, capillary pore adsorption and fine particle adsorption. The soil with a larger clay mass fraction has more capillary content, more storage pores, a larger specific surface area, a stronger adsorption capacity, and a stronger water storage capacity. As shown in the soil-water characteristic curve, the soil volume moisture content of each water suction section decreases with the increase of clay mass fraction. In the medium and low water suction sections, the soil with a larger clay mass fraction has a higher capillary content, a stronger capillary absorption capacity, and can hold more water. In the high water suction section, the huge surface area and surface charge of the clay give it a very strong ability to adsorb water molecules, forming a thicker adsorbed water layer or water film. The pores between the clay particles are extremely fine, forming a thicker adsorbed water layer or water film. The pores between the clay particles are extremely fine, and it is possible for the adsorbed water film to retain a certain amount of water under the action of capillary force. Moreover, the soil with a larger clay mass fraction has a stronger effect.

[0090] The purpose of the particle size gradation design of the odor adsorption layer I material in the enclosure adsorption subsystem 18 is to increase the proportion of fine particles, thereby increasing the adsorbent material in the odor adsorption layer I material and improving the odor adsorption capacity; and to increase the total specific surface area of ​​the odor adsorption layer I material, thereby increasing the contact area with the odor and improving the odor adsorption efficiency and capacity; by increasing the proportion of fine particles, the water holding capacity of the odor adsorption layer I can be effectively enhanced, the permeability coefficient can be reduced, and the amount of odor passing through the odor adsorption layer I per unit time can be controlled and the odor passing time can be extended, thereby extending the odor adsorption reaction time of the odor in the odor adsorption layer I and improving the odor adsorption effect. The parameter design of the odor adsorption layer II of the intermediate adsorption subsystem is the same.

[0091] The enclosure adsorption subsystem 18 has an outer cross-section as shown in FIG. Figure 1 If it is trapezoidal, it includes the plane and the inclined slope. If the outer cross-section is triangular, it only includes the inclined slope.

[0092] The closure adsorption subsystem 18, the vegetation layer 2 includes soil capable of cultivating vegetation 1, and the thickness of the vegetation layer 2 meets the root system requirements of the planted vegetation 1, and the thickness of the vegetation layer 2 is ≥0.5m; the drainage layer 3 is made of recycled coarse aggregate prepared by recycling construction waste buried in the landfill, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compacted relative density ≥0.9; a water-permeable and air-permeable insulating material layer 9 is provided between each layer to prevent the mixing of the raw materials of each layer; the original concrete strength of the material of the odor adsorption layer I and the odor adsorption layer II is not less than C30, and the original concrete strength of the other layers except the vegetation layer is not less than C10. The water-permeable and air-permeable insulating material layer 9 is a geotextile.

[0093] The preparation method of the closure adsorption subsystem 18 includes the following steps: (1) preparing materials according to the raw material requirements of each functional layer; before preparing the recycled aggregate and recycled powder, impurities such as wood, steel bars, and slag in the construction waste should be removed through pretreatment, leaving only waste concrete and mortar stone; (2) laying each functional layer according to the requirements of each layer.

[0094] The intermediate adsorption subsystem 19 includes three functional layers, which are, from top to bottom, an upper gas collection layer 10 of the intermediate adsorption subsystem, an odor adsorption layer II 11, and a lower gas collection layer 12.

[0095] The three functional layers of the intermediate adsorption subsystem 19, the upper gas collection layer 10, the odor adsorption layer II 11, and the lower gas collection layer 12 are all constructed of recycled materials prepared by recycling construction waste buried in landfills, preferably using discarded high-strength concrete. It is required that the strength of the original concrete of the upper and lower gas collection layers is not less than C10, and the strength of the original concrete of the odor adsorption layer II material of the intermediate adsorption subsystem is not less than C30; and before preparing recycled aggregates from construction waste, impurities (including slag, steel bars, wood, glass, plastic, bricks, paper, fabrics, etc.) are removed, leaving only concrete and mortar blocks, and the weight of concrete and mortar accounts for not less than 95%.

[0096] The intermediate adsorption subsystem 19 and the upper gas collection layer 10 are constructed of recycled coarse aggregate, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compacted relative density of not less than 0.9. The function of the upper gas collection layer of the intermediate adsorption subsystem is to separate the odor adsorption layer II of the intermediate adsorption subsystem from the garbage body thereon to avoid direct contact between the two; a gas collection layer with high permeability is formed between the odor adsorption layer II of the intermediate adsorption subsystem and the garbage body thereon, so that H2S gas can overflow downward from the garbage body above the odor adsorption layer II and be enriched in the upper gas collection layer; under the control of the upper gas collection layer exhaust device 15, the partial gas pressure value of H2S gas in the upper gas collection layer is controlled, and then the partial gas pressure distribution of H2S gas in the odor adsorption layer II of the intermediate adsorption subsystem is controlled, thereby affecting the progress of the odor adsorption reaction.

[0097] The odor adsorption layer II of the intermediate adsorption subsystem 19 is made of recycled fine aggregate and recycled powder prepared by recycling construction waste, and its thickness is 0.3-0.6m. The other material performance parameters are the same as the parameter requirements of the odor adsorption layer of the closure adsorption subsystem. The odor adsorption layer II of the intermediate adsorption subsystem serves as a temporary odor adsorption when the intermediate adsorption subsystem is in place, and on the other hand, it can continue to adsorb odor as an intermediate interlayer of the garbage body after closure.

[0098] The lower gas collection layer 12 of the intermediate adsorption subsystem 19 is constructed of recycled coarse aggregate, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compacted relative density of not less than 0.9. The function of the lower gas collection layer of the intermediate adsorption subsystem is to separate the odor adsorption layer II of the intermediate adsorption subsystem from the garbage body below it to avoid direct contact between the two; a gas collection layer with high permeability is formed between the odor adsorption layer II of the intermediate adsorption subsystem and the garbage body below it, so that H2S gas can overflow upward from the garbage body below the odor adsorption layer II and be enriched in the lower gas collection layer; under the control of the lower gas collection layer exhaust device 16, the partial gas pressure value of H2S gas in the lower gas collection layer is controlled, and then the partial gas pressure distribution of H2S gas in the odor adsorption layer II of the intermediate adsorption subsystem is controlled, thereby affecting the progress of the odor adsorption reaction.

[0099] A bottom anti-seepage lining is also provided below and on the side of the lowest garbage body, so that the odor adsorption system in the present invention and the garbage body, as well as the bottom anti-seepage lining in the prior art, constitute "bottom anti-seepage lining-garbage body-intermediate adsorption subsystem-garbage body-intermediate adsorption subsystem-...-garbage body-sealing adsorption subsystem", and the bottom anti-seepage lining is an anti-seepage cushion layer 17. In this structure formed by the staggered superposition of the composite structure of "garbage body-intermediate adsorption subsystem", the intermediate adsorption subsystem and the garbage body 8 are in full contact, that is, the odor adsorption layer II of the intermediate adsorption subsystem is mixed in the garbage, and multi-level adsorption is achieved. On the one hand, the intermediate adsorption subsystem serves as a temporary odor adsorption during the landfill operation, and on the other hand, it can continue to adsorb odor as an intermediate interlayer of the garbage body 8 after the closure.

[0100] In the odor adsorption system of the landfill, a gas collecting layer exhaust device is provided at the side of the gas collecting layer, for example, the gas collecting layer exhaust device here is the gas collecting layer I exhaust device 14, the upper gas collecting layer exhaust device 15 or the lower gas collecting layer exhaust device 16.

[0101] A water-permeable and air-permeable insulating material layer 9 is provided between all functional layers of the closure adsorption subsystem and the intermediate adsorption subsystem, and between the functional layer and the garbage body. The insulating material layer 9 is preferably a geotextile. Because the particle sizes of the particles between the functional layers are quite different, in order to prevent the smaller particles from falling into the larger particles, the geotextile is laid in advance to prevent the mixing of the particles. In addition, a geotextile may be laid between the gas collection layer I and the garbage body to prevent the mixing of the particles.

[0102] Among them, the water storage of the anti-seepage layer and the odor adsorption layer I is mainly achieved through macropore accommodation, capillary pore absorption and fine aggregate particle absorption. The soil with a larger mass fraction of clay particles has more capillary content, more storage pores, a larger specific surface area, a stronger adsorption capacity, and a stronger water storage capacity. As shown in the soil-water characteristic curve, the soil volume moisture content in each water suction section decreases with the increase of clay mass fraction. In the medium and low water suction sections, the soil with a larger mass fraction of clay particles has more capillary content, a stronger capillary absorption capacity, and more water; in the high water suction section, the huge surface area and surface charge of clay particles make it have a strong ability to absorb water molecules, forming a thicker adsorption water layer or water film, and the pores between clay particles are extremely fine, forming a thicker adsorption water layer or water film, and the pores between clay particles are extremely fine, and it is possible to retain a certain amount of water outside the adsorption water film under the action of capillary force, and the soil with a larger mass fraction of clay particles has a stronger effect.

[0103] The mechanism of action of the landfill odor adsorption system involved in the present invention is:

[0104] The core functions of the landfill odor adsorption system involved in the present invention include anti-seepage and air-locking functions, as well as the H2S odor adsorption function unique to the present invention. Among them, the anti-seepage and air-locking function is realized by the landfill closure adsorption subsystem.

[0105] Attached Figure 7 This is a schematic diagram of the anti-seepage and air-tightening principle of the present invention. The anti-seepage function is mainly achieved by the double capillary blocking covering layer formed by the sealing adsorption subsystem, that is, the anti-seepage layer and the drainage layer form the first capillary blocking covering layer, and the second capillary blocking covering layer formed by the odor adsorption layer I and the gas collection layer I located directly below the first capillary blocking covering layer, wherein the anti-seepage of the first capillary blocking covering layer is the main function, and the second capillary blocking covering layer is the auxiliary function. The anti-seepage working mechanism of the double capillary blocking covering layer is:

[0106] When it rains 20, most of the rainwater will form slope runoff 21 and drain down the slope, entering the rainwater collection and drainage system of the landfill, and a small amount of rainwater will infiltrate into the vegetation layer 2. The rainwater entering the vegetation layer is stored in the vegetation layer. When the storage capacity of the vegetation layer is exceeded, the rainwater that infiltrates the vegetation layer 2 will be stored in the soil pores of the vegetation layer 2 on the one hand, and the other part will continue to infiltrate into the drainage layer 3. The saturated permeability coefficient of the drainage layer 3 is large, and the permeability coefficient of the impermeable layer 4 is small. Most of the water entering the drainage layer will be laterally drained in the drainage layer 3 (i.e., the drainage layer will be laterally drained 22), and a small amount will infiltrate into the impermeable layer 4.

[0107] Part of the water that penetrates into the impermeable layer 4 is stored in the pores of the impermeable layer 4, and the other part continues to infiltrate to the interface between the impermeable layer 4 and the drainage layer. This interface will form a capillary barrier effect due to the difference in particle size and air intake value between the upper and lower materials. At this time, under the action of the capillary barrier effect, the water that penetrates into the impermeable layer will not continue to infiltrate, and under the action of the slope, it will be drained laterally down the slope along the interface between the impermeable layer 4 and the drainage layer 5. As the amount of water stored in the impermeable layer increases, the suction of the impermeable layer decreases, and the capillary barrier effect between the impermeable layer 4 and the drainage layer 5 will be weakened or even disappear until the infiltrated water breaks through the capillary barrier covering layer. At this time, the first capillary barrier covering layer fails, and the infiltrated water begins to enter the drainage layer 5. Then, the second capillary barrier covering layer begins to play a role. Most of the water that infiltrates into the drainage layer 5 will be drained along the slope in the drainage layer 5 (i.e., the drainage layer will be drained laterally 23), and a small amount will infiltrate into the odor adsorption layer I. Because the odor adsorption layer I is protected by the first capillary barrier covering layer composed of the anti-seepage layer and the drainage layer, the odor adsorption layer I is maintained at a high moisture content for a long time, so the water storage capacity of the odor adsorption layer I is relatively weak. At this time, the anti-seepage function of the second capillary barrier covering layer mainly relies on the capillary barrier effect of the interface between the odor adsorption layer I and the gas collection layer I. Under the action of this barrier effect, the water entering the odor adsorption layer I is blocked on the interface between the odor adsorption layer I and the gas collection layer I, and is drained along the interface. Under the joint action of the double capillary barrier covering layer, rainwater can be effectively prevented from infiltrating into the garbage body to form leachate.

[0108] During periods of no rainfall, the water stored in the vegetation layer and impermeable layer can be released into the atmosphere through surface evaporation and transpiration of plants in the vegetation layer.

[0109] In this way, through water storage / drainage during rainfall and release by evaporation during non-rainfall periods, the enclosure adsorption subsystem of the present invention achieves water balance in the dry-wet cycle of weather.

[0110] In addition, under the protection of the first capillary barrier covering layer formed by the anti-seepage layer and the drainage layer, the second capillary barrier covering layer can maintain a high moisture content. Under a high moisture content, the air permeability coefficient of the odor adsorption layer I is relatively low, which can effectively prevent the odor from escaping into the atmosphere, thereby achieving the air-locking function.

[0111] Attached Figure 5 and 6 The schematic diagram of the odor adsorption principle of the present invention. The H2S odor adsorption function involved in the present invention is mainly achieved through the layer-by-layer adsorption of the intermediate adsorption subsystem constructed during the landfilling, and the final adsorption of the closure adsorption subsystem, that is, the combined adsorption system composed of several intermediate adsorption subsystems and the final closure adsorption subsystem realizes odor adsorption.

[0112] The principle of odor adsorption in the intermediate adsorption subsystem is that odor adsorption in the intermediate adsorption subsystem 19 is mainly achieved through gas collection in the upper gas collection layer 10 and the lower gas collection layer 12 and adsorption reaction in the odor adsorption layer II 11. The particles in the upper and lower gas collection layers are larger in size, pore volume, and permeability coefficient, and can collect the landfill gas generated by the upper and lower garbage bodies, and enrich and maintain a higher H2S partial pressure in the upper and lower gas collection layers, that is, the upper and lower odor adsorption layers II of the intermediate adsorption subsystem are in an environment with a higher H2S partial pressure, which can accelerate the chemical reaction between the recycled aggregate and the H2S gas in the odor adsorption layer II of the intermediate adsorption subsystem, thereby accelerating the adsorption of H2S. In addition, the upper and lower gas collection layers are respectively equipped with exhaust devices to control the gas pressure of the upper and lower gas collection layers, especially the partial pressure of H2S gas, and then control the distribution of the partial pressure of H2S gas in the odor adsorption layer II with depth, so as to achieve the best odor adsorption effect.

[0113] As attached Figure 6 As shown, the present invention requires several intermediate adsorption subsystems, Figure 6 The intermediate adsorption subsystem with serial number N is used as an example. In the intermediate adsorption subsystem with serial number N: the depth of contact between the upper gas collection layer and the garbage body is D N0 The depth of contact between the upper gas collection layer and the odor adsorption layer Ⅱ11 is D N1 The depth of contact between the lower gas collection layer and the odor adsorption layer Ⅱ11 is D N2 , the depth of contact between the lower gas collecting layer and the garbage body is D N3 The partial pressure of H2S gas in the upper and lower gas collecting layers can be regarded as P N2 , the burial depth of the longitudinal middle thickness of the odor adsorption layer II is D NC , the burial depth is D NC The partial pressure of H2S gas at N1 . From D in the odor adsorption layer NC To D N1 and D NC To D N2 The H2S gas pressure along the vertical direction increases with the depth from P N1 To P N2 The linear distribution of .

[0114] Generally, for the H2S gas partial pressure P of the odor adsorption layer II of the intermediate adsorption subsystem N1 The control value is between 0kPa and 2kPa, and the optimal control value is 0kPa. The partial pressure P of H2S gas in the upper and lower gas collecting layers of the intermediate adsorption subsystem N1 The control value is between 0kPa and 10kPa, ensuring that the H2S gas partial pressure P in the intermediate adsorption subsystem N1 and P N2Under the condition that the standard is not exceeded, the partial pressure P of H2S gas in the intermediate adsorption subsystem should be appropriately increased. N1 and P N2 The value can effectively improve the efficiency and adsorption effect of the odor adsorption reaction. The partial pressure P of the H2S gas in the upper and lower gas collection layers is controlled by the upper gas collection layer exhaust device 15 and the lower gas collection layer exhaust device 16. N2 value, thereby controlling the distribution of the partial pressure of H2S gas in the odor adsorption layer II with depth, so as to achieve the best odor adsorption effect.

[0115] The intermediate adsorption subsystem in the present invention, the garbage body, and the bottom anti-seepage lining in the prior art constitute "bottom anti-seepage lining-garbage-intermediate adsorption subsystem-garbage-intermediate adsorption subsystem-...-garbage-sealing adsorption subsystem". In this structure formed by the staggered superposition of the composite structure of "garbage-intermediate adsorption subsystem", the intermediate adsorption subsystem and the garbage body are in full contact, that is, the odor adsorption layer II of the intermediate adsorption subsystem is mixed in the garbage, and multi-level adsorption is achieved. On the one hand, the intermediate adsorption subsystem acts as a temporary odor adsorption when it is an intermediate adsorption subsystem, and on the other hand, it can continue to adsorb odor as an intermediate interlayer of the garbage body after the closure.

[0116] The principle of odor adsorption in the sealing adsorption subsystem 18 is that odor adsorption in the sealing adsorption subsystem is mainly achieved through air sealing in the anti-seepage layer 4, air collection in the drainage layer 5 and the gas collection layer Ⅰ7, and adsorption reaction in the odor adsorption layer Ⅰ6. The air-sealing function of the anti-seepage layer helps to maintain a higher air pressure and a higher concentration of H2S gas below it, which can accelerate the chemical reaction between the recycled aggregate and the H2S gas in the odor adsorption layer Ⅰ, thereby accelerating the adsorption of H2S; the particles in the drainage layer and the gas collection layer Ⅰ have a larger particle size, a higher pore volume, and a larger permeability coefficient, which can enrich a large amount of gas. In addition, the air-sealing function of the odor adsorption layer Ⅰ6 helps to maintain a higher air pressure and a higher concentration of H2S gas in the gas collection layer Ⅰ7, which can accelerate the chemical reaction between the recycled aggregate and the H2S gas in the odor adsorption layer Ⅰ6, thereby accelerating the adsorption of H2S. In addition, the gas collection layer I and the guide layer are respectively equipped with exhaust devices - the guide layer exhaust device 13 and the gas collection layer I exhaust device 14, which are used to control the air pressure of the odor adsorption layer I and the gas collection layer I, especially the partial pressure of H2S gas, and then control the distribution of the partial pressure of H2S gas in the odor adsorption layer I with depth, so as to achieve the best odor adsorption effect.

[0117] According to the basic theory of soil mechanics, the particles of the drainage layer 3, the drainage layer 5 and the gas collection layer Ⅰ7 are relatively large, and the gas permeability is relatively good. The gas pressure inside them can be regarded as being equal everywhere. Figure 5As shown, the partial pressures of H2S gas in the drainage layer 5 and the gas collecting layer Ⅰ7 are P1 and P2 respectively, and the partial pressure of H2S gas in the odor adsorption layer Ⅰ6 presents a linear distribution from P1 to P2 with the vertical depth. Figure 5 In the figure, the surface burial depth of vegetation layer 2 is D0, the surface burial depth of drainage layer 3, i.e., the interface depth of vegetation layer 2 and drainage layer 3, is D1, the surface burial depth of anti-seepage layer 4, i.e., the interface depth of drainage layer 3 and anti-seepage layer 4, is D2, the surface burial depth of drainage layer 5, i.e., the interface depth of anti-seepage layer 4 and drainage layer 5, is D3, the surface burial depth of odor adsorption layer Ⅰ6, i.e., the interface depth of drainage layer 5 and odor adsorption layer Ⅰ6, is D4, the surface burial depth of gas collection layer Ⅰ7, i.e., the interface depth of odor adsorption layer Ⅰ6 and gas collection layer Ⅰ7, is D5, and the critical depth at which the partial pressure of H2S gas is 0 kPa is D T , D T Between D2 and D3. The vegetation layer 2, drainage layer 3 and anti-seepage layer 4 are from surface D2 to depth D T The partial pressure of H2S gas is 0kPa. T To D3, it presents a linear distribution from 0 kPa to P1 along the vertical direction.

[0118] In this embodiment of the present invention, the exhaust device of the gas collection layer I can control the partial pressure P2 of the H2S gas in the gas collection layer I by exhausting air, and the exhaust device of the guide layer can control the partial pressure P1 of the H2S gas in the guide layer 5 by exhausting air. Usually, the control value of the partial pressure P1 of the H2S gas in the guide layer is between 0kPa and 1kPa. The control value of the partial pressure P2 of the H2S gas in the gas collection layer I is between 0kPa and 10kPa. Under the condition that the partial pressure P1 of the H2S gas in the guide layer is not exceeded, appropriately increasing the partial pressure P2 of the H2S gas in the gas collection layer I can effectively improve the occurrence efficiency and adsorption effect of the odor adsorption reaction. The partial pressure P2 of the H2S gas in the gas collection layer I is controlled by the exhaust device of the gas collection layer I.

[0119] By the combined action of the exhaust layer exhaust device 13 and the gas collection layer I exhaust device 14, the partial pressure distribution of the H2S gas in the entire enclosure adsorption subsystem is controlled to achieve the best odor adsorption effect.

[0120] The exhaust device 13 of the guide layer can control D T When D T =D3=D4, indicating that the partial pressure of H2S gas in the impermeable layer 4 and the drainage layer 5 is 0kPa, that is, no H2S gas overflows from the odor adsorption layer I. T = D1=D2, the partial pressure of H2S gas on the surface of the drainage layer and the anti-seepage layer is 0kPa, reaching a critical state, that is, no H2S gas overflows from the anti-seepage layer into the vegetation layer to affect vegetation growth.

[0121] It should be noted that the exhaust layer exhaust device 13, the gas collection layer I exhaust device 14, the upper gas collection layer exhaust device 15 and the lower gas collection layer exhaust device 16 are not permanent and full-time operating devices, but are only auxiliary facilities. Through exhaust and exhaust, they ensure the partial pressure distribution of H2S gas in the sealing adsorption subsystem, so that the sealing adsorption subsystem is in the best state for odor adsorption; at the same time, ensure that no H2S gas overflows from the anti-seepage layer to pollute the atmosphere and the surrounding environment.

[0122] The odor adsorption mechanism of the odor adsorption material involved in the present invention is: using construction waste recycled aggregate as the construction material of the odor adsorption layer, the unreacted quicklime (CaO) or slaked lime (Ca(OH)2) and other alkaline substances remaining in the construction waste react with the acidic substances (mainly H2S) in the odor to produce an acid-base neutralization reaction. The chemical reaction equation is as follows:

[0123]

[0124] In addition, the characteristics of the odor adsorption layer, such as high-strength concrete crushing preparation, large thickness, high compaction, high proportion of fine particles, high proportion of concrete and mortar blocks, high water content and moisturizing function of the anti-seepage layer, can effectively increase the theoretical adsorption capacity of the odor adsorption layer and create an environment suitable for the adsorption reaction, thereby better improving the actual adsorption effect.

[0125] The method for making the adsorption system involved in the present invention is as follows:

[0126] (1) Prepare the ingredients.

[0127] The soil material of the vegetation layer can be obtained nearby, and the material requirements of the vegetation soil must meet relevant specifications. The present invention does not make any special requirements.

[0128] The drainage layer, anti-seepage layer, drainage layer, odor adsorption layer I and gas collection layer I of the closure adsorption subsystem and the recycled aggregates required by the intermediate adsorption subsystem should be prepared from abandoned construction waste, preferably from construction waste buried in landfills. The preparation method is as follows:

[0129] A construction waste crushing station is set up in the landfill, and the construction waste to be landfilled in the landfill is directly transported to the construction waste crushing station to prepare recycled coarse aggregate, recycled fine aggregate and recycled powder. Before preparing recycled aggregate, impurities such as wood, steel bars, and slag in the construction waste should be removed by pretreatment, leaving only abandoned concrete and mortar stone. Then, the construction waste is prepared into recycled coarse aggregate, recycled fine aggregate and recycled powder through processes such as crushing, screening, removing impurities, grinding, drying and composite material selection. Recycled coarse aggregate and recycled fine aggregate with corresponding predetermined particle size requirements are prepared through crushing, grinding and screening processes, and micro powder is collected by dust collection equipment to prepare recycled powder. The recycled powder is mixed with recycled fine aggregate to prepare the recycled fine material required for the odor adsorption layer. It should be noted that in the production process of recycled aggregate at home and abroad, recycled coarse aggregate and recycled fine aggregate can be prepared by crushing and grading, and micro powder (particle size can be less than 0.15mm) can be collected by dust collection equipment to prepare recycled powder.

[0130] Since the regenerated fine material of the odor adsorption layer in the present invention has requirements for its powder ratio, the regenerated fine material required by the present invention can be prepared by mixing the regenerated fine aggregate and the regenerated powder in a certain ratio in the actual industrial production process (i.e., composite material selection). The materials required for the closure adsorption subsystem and the intermediate adsorption subsystem need to meet the above requirements.

[0131] The specific production and processing requirements of recycled materials can refer to or follow the production specifications for recycled aggregates in construction projects (such as GB / T25177-2010 Recycled coarse aggregate for concrete and DB894.1-Technical Specifications for Application of Recycled Sand Powder (Shanghai)), so as to facilitate large-scale industrial production and reduce process difficulty and production costs.

[0132] It can be understood that the obtained recycled coarse aggregate, recycled fine aggregate and recycled powder can be used to construct the landfill odor adsorption system on the one hand, and can also be used for other civil engineering construction on the other hand; similarly, the raw materials for constructing the closure adsorption subsystem can also be obtained from other landfills or other places with construction waste crushing stations.

[0133] (2) Add water, mix and maintain.

[0134] Before constructing the enclosure adsorption subsystem and the intermediate adsorption subsystem separately, the required materials need to be mixed with water to the optimal moisture content, and then sealed and cured to ensure uniform moisture. The optimal moisture content of each layer of material needs to be determined by experimental research in advance, and the determination method should comply with the requirements of relevant geotechnical test specifications (such as GBT 50123-2019 Geotechnical Test Method Standard). When configuring the optimal moisture content, it should be ensured that the water is added evenly and fully stirred without large agglomeration. The material should be cured in a closed and light-shielded environment, usually for 3-10 days.

[0135] (3) Laying of the intermediate adsorption subsystem: A bottom anti-seepage lining is also provided below and on the side of the lowest garbage body. The bottom anti-seepage lining - the anti-seepage cushion layer 17 is laid first (performed according to the existing technology), and then the garbage is landfilled. After the garbage landfill operation is completed, it is leveled and rolled to form a garbage body; then a layer of geotextile is laid on the garbage body. Then the compacted coarse aggregate of the lower gas collection layer is laid on the geotextile, and the recycled coarse aggregate is laid in layers and fully compacted. The thickness of each layer should not be too thick (generally not more than 10cm), and the compaction degree must meet the requirements (relative density not less than 0.9). Then the geotextile is laid. Then the odor adsorption layer II is laid on the geotextile. When laying, it needs to be laid in layers and fully compacted. The thickness of each layer should not exceed 10cm, and the compaction degree should not be less than 95%. When compacting in layers, pay attention to scraping the surface of the recycled fine material layer after compaction in front, so that the front and back layers can fully contact and combine.

[0136] After the odor adsorption layer II is laid, it is necessary to manually sprinkle water or air dry the odor adsorption layer II so that its moisture content reaches the predetermined adsorption reaction moisture content. Generally speaking, the odor adsorption layer II can play a role in anti-seepage and deodorization during temporary covering, and can also meet the requirements for anti-seepage, air-tightness and deodorization during landfill operations. However, if the surrounding environment of the landfill has high requirements for anti-seepage, air-tightness and deodorization, a higher level of anti-seepage and air-tightness can be achieved by laying a layer of geomembrane on the odor adsorption layer II. At this time, the anti-seepage and air-tightness functions of the intermediate adsorption subsystem are mainly realized by the geomembrane. The laying, welding, and maintenance of geomembranes need to be carried out in accordance with relevant specifications (such as GB / T 50290-2014 Technical Specifications for the Application of Geosynthetics), and the present invention does not make special requirements.

[0137] When the next round of landfill operation is carried out, it is only necessary to lay the upper gas collection layer on the odor adsorption layer II. The laying method is the same as the lower gas collection layer. First lay the geotextile, then lay the upper gas collection layer on the geotextile, and then landfill the garbage. When the geomembrane is laid, it is necessary to peel off the geomembrane first, and then start laying the upper gas collection layer and the subsequent new round of landfill operation. The geomembrane can be reused in the intermediate adsorption subsystem after the next round of landfill operation is completed, and the use method is the same.

[0138] After the next round of landfill operation is completed, the intermediate adsorption subsystem will continue to be laid, and then the next round of landfill operation will be carried out until the predetermined landfill elevation is reached for sealing, and the sealing adsorption subsystem will be laid.

[0139] After the intermediate adsorption subsystem is laid, it needs to be monitored and maintained. In addition to the monitoring of anti-seepage drainage, leachate, garbage degradation, garbage body sedimentation, etc. required by the traditional intermediate adsorption subsystem, it is also necessary to carry out the integrity and soundness of the intermediate adsorption subsystem, the generation and distribution of landfill gas (especially H2S), and the operation of the odor adsorption function of the intermediate adsorption subsystem.

[0140] (4) Laying of the closure adsorption subsystem: After the landfill operation is completed, the landfill should be cleaned, leveled and compacted. Pay attention to cleaning up sharp stones, tree roots and other debris, and all debris should be cleaned up. The base surface is not allowed to have local unevenness. The cleaned base surface should be compacted with a tamping hammer or tamping board to make it dense and flat.

[0141] Then, geotextile is laid on the garbage body first, and then the compacted coarse aggregate of gas collection layer I is laid on the geotextile. The recycled coarse aggregate is laid in layers and fully compacted. The thickness of each layer should not be too thick (generally not more than 10cm), and the compaction degree must meet the requirements (relative density not less than 0.9). Then, geotextile is laid, and then the odor adsorption layer I is laid on the geotextile. When laying, it needs to be laid in layers and fully compacted. The thickness of each layer should not exceed 10cm, and the compaction degree should not be less than 95%. When compacting in layers, pay attention to scraping the surface of the recycled fine material layer after compaction in front, so that the front and back layers can fully contact and combine.

[0142] After the odor adsorption layer I is laid, it is necessary to manually sprinkle water or dry it in the sun so that its moisture content reaches the predetermined moisture content of the adsorption reaction.

[0143] Then lay the geotextile, and then lay the drainage layer on the geotextile. The laying method and requirements of the drainage layer are the same as those of the gas collection layer I.

[0144] Then lay the geotextile, and then lay the anti-seepage layer on the geotextile. When laying, it needs to be laid in layers and fully compacted. The thickness of each layer shall not exceed 10cm, and the compaction degree shall not be less than 95%. When compacting in layers, pay attention to scraping the surface of the recycled fine aggregate layer that has been compacted before, so that the front and back layers can fully contact and bond.

[0145] Then lay the geotextile, and then lay the drainage layer on the geotextile. The laying steps and requirements of the drainage layer are the same as those of the drainage layer. Then lay the geotextile on the drainage layer.

[0146] Then, the geotextile is laid, and then the vegetation layer is laid on the geotextile. The soil material of the vegetation layer is compacted in layers, and the hair needs to be scraped between the layers. Then, greening is planted on the vegetation layer. Fertilization, tillage construction, maintenance, irrigation, etc. of the vegetation are carried out in accordance with relevant specifications, and the present invention does not make special requirements.

[0147] After the closure and adsorption subsystem is laid, it needs to be monitored and maintained. In addition to the monitoring of anti-seepage drainage, leachate, garbage degradation, garbage body sedimentation, etc. required by the traditional closure and adsorption subsystem, it is also necessary to carry out the integrity and soundness of the closure and adsorption subsystem, the generation and distribution of landfill gas (especially H2S), and the operation of the odor adsorption function of the closure and adsorption subsystem. In addition, vegetation maintenance is also required.

[0148] Among them, in the laying step, the geotextile laid between the functional layers is mainly used to prevent the large difference in particle size between the upper and lower layers from causing particle migration and the smaller particles from falling into the larger particles and mixing with each other. The geotextile is required to be water-permeable and air-permeable, and the strength meets the requirements. The present invention requires that the geotextile used meets the basic performance requirements of the geotextile conventionally used in landfills, and the present invention does not make special requirements.

[0149] In addition, compared with the operating characteristics of similar landfills, the operating characteristics of the landfill where the odor adsorption system involved in the present invention is located are "small amount and multiple times", that is, the thickness of a single landfill is reduced, and the total number of landfill operations is increased; in this way, the number of the composite structure of "garbage-intermediate adsorption subsystem-garbage" stacked up and down can be increased. Its design concept is to increase the number of intermediate adsorption subsystem layers in the garbage body as much as possible, and to increase the total contact area between the odor adsorption layer and the garbage body as much as possible, so as to improve the odor adsorption capacity and adsorption effect.

[0150] The thickness of a single landfill operation and the corresponding thickness of the intermediate adsorption subsystem and the thickness of the closure adsorption subsystem suggested by the present invention all need to be calculated and verified in order to match each other. Generally speaking, the increase in the thickness of a single landfill operation and the increase in the total amount of sulfur-containing organic matter in the garbage landfilled in a single landfill will inevitably lead to an increase in the theoretical amount of odor H2S generated in the garbage landfilled in a single landfill, which will inevitably lead to an increase in the thickness of the odor adsorption layer II in the required intermediate adsorption subsystem. In addition, the thickness of the odor adsorption layer is also related to the adsorption capacity of the odor adsorption layer material. When the adsorption capacity of the odor adsorption layer material increases, the required adsorption layer thickness will also decrease accordingly. Therefore, the thickness design of the intermediate adsorption subsystem involved in the present invention is related to the total amount of H2S gas that can be generated by the garbage in a single landfill operation and the H2S adsorption capacity of the adsorption layer material. This design concept is very different from the design concept of the traditional intermediate covering layer.

[0151] Specifically, Figure 1 As shown, the present invention relates to an odor adsorption system for a landfill, which is composed of a landfill closure adsorption subsystem 18 and a plurality of intermediate adsorption subsystems 19. The raw materials are mostly recycled construction waste and are used for odor adsorption.

[0152] The vegetation layer 2 is made of soil from the surrounding area of ​​the landfill. In this embodiment, loess from the surrounding area is selected, which is rich in nutrients and can meet the requirements of relevant regulations for vegetation soil in the landfill odor adsorption system. Therefore, no additional nutrients need to be added, and the implementation of the present invention does not exceed the requirements of relevant regulations. The thickness of the vegetation layer 2 is 0.5m, the compaction degree is 80%, and its particle size curve is shown in the attached figure. Figure 4 shown.

[0153] The drainage layer 3 is located between the vegetation layer 2 and the anti-seepage layer 4, and is constructed of recycled coarse aggregate prepared by recycling construction waste buried in landfill sites. It has a thickness of 0.3m, a particle size of 20-40mm, and a compacted relative density of 0.9.

[0154] The anti-seepage layer 4 is located on the top of the closure adsorption subsystem and is made of recycled fine aggregates prepared by recycling construction waste buried in the landfill. Its thickness is 0.4m, and the maximum particle size of the recycled fine aggregate is 2mm. Its particle size gradation curve is as shown in the attached figure. Figure 4 The anti-seepage layer is constructed by layered compaction, with a compaction degree of 95% and a permeability coefficient between 10 -8 m / s -10 -7 m / s, the water absorption rate is 8%, and the mechanical air intake value of unsaturated soil is 5.5kPa.

[0155] The drainage layer 5 is made of recycled coarse aggregates made from construction waste landfilled in landfills. The drainage layer is constructed of recycled coarse aggregates with a thickness of 0.2m, a particle size of 20-40mm, a compacted relative density of 0.9, and an unsaturated soil mechanics air intake value of 1.2kPa.

[0156] The odor adsorption layer I6 is made of recycled fine aggregate and recycled powder prepared by recycling construction waste, with a thickness of 0.8m, a compaction degree of 95%, a maximum particle size of 2mm, and an effective particle size d 10 =0.02mm, the air permeability coefficient of the compacted recycled aggregate in the odor adsorption layer I at the maximum dry density is 10 -7 m / s—10 -8 m / s, air intake value 5kPa, water absorption rate 12%, pore water saturation 60%.

[0157] The gas collection layer Ⅰ7 is constructed with recycled coarse aggregate, with a thickness of 0.3m, a particle size of 20-40mm, and a compacted relative density of not less than 0.9.

[0158] The intermediate adsorption subsystem 19 includes three functional layers, which are, from top to bottom, an upper gas collection layer of the intermediate adsorption subsystem, an odor adsorption layer II of the intermediate adsorption subsystem, and a lower gas collection layer.

[0159] The upper gas collection layer 10 of the intermediate adsorption subsystem is constructed with recycled coarse aggregate, with a thickness of 0.2m, a particle size of 20-40mm, and a compacted relative density of 0.9.

[0160] Among them, the odor adsorption layer II11 of the intermediate adsorption subsystem adopts recycled fine material made by mixing recycled fine aggregate and recycled powder prepared by recycling construction waste, and its thickness is 0.4m. The other material performance parameters are the same as the parameter requirements of the odor adsorption layer I of the closure adsorption subsystem.

[0161] The lower gas collection layer 12 of the intermediate adsorption subsystem is constructed with recycled coarse aggregate, with a thickness of 0.2m, a particle size of 20-40mm, and a compacted relative density of 0.9.

[0162] The particle size curves of the above layers are shown in the attached Figure 4 shown.

[0163] Among them, the recycled aggregate described in the above-mentioned functional layer material is preferably recycled aggregate prepared from discarded high-strength concrete, and the strength of the original concrete is required to be not less than C20; and before preparing the recycled aggregate from construction waste, impurities (including slag, steel bars, wood, glass, plastic, bricks, paper, fabric, etc.) are removed, and only concrete and mortar blocks are retained, and the weight proportion of concrete and mortar is not less than 95%.

[0164] A water-permeable and air-permeable insulating material layer 9 is provided between the functional layers. The insulating material layer is preferably a geotextile, which should meet the requirements of relevant specifications. The purpose of setting the geotextile is that since the particle sizes between the functional layers of the closure adsorption subsystem and the intermediate adsorption subsystem are quite different, in order to prevent the smaller particles from falling into the larger particles, the pre-laying of the geotextile can prevent the mutual mixing. In addition, a geotextile is also laid between the air collection layer I and the garbage body to prevent mutual mixing.

[0165] It should be noted that in order to solve the problem that the strength of the traditional earthen cover layer is too low, large and medium-sized construction machinery cannot pass normally on the earthen cover layer during the next stage of landfill, causing further construction difficulties, the drainage layer, drainage layer, odor adsorption layer and gas collection layer in this embodiment require a minimum bearing ratio (CBR) > 3% during the construction process to ensure sufficient strength to facilitate the passage of large and medium-sized machinery in the subsequent landfill process.

[0166] It should be noted that the particle grading shown in the above particle grading curve is not the only one and can be adjusted according to the characteristics and requirements of different landfills in specific application scenarios.

[0167] The technical solutions provided by the embodiments of the present invention are introduced in detail above. Specific examples are used herein to illustrate the principles and implementation methods of the embodiments of the present invention. The description of the above embodiments is only applicable to help understand the principles of the embodiments of the present invention. At the same time, for those skilled in the art, according to the embodiments of the present invention, there will be changes in the specific implementation methods and application scopes. In summary, the content of this specification should not be understood as limiting the present invention.

Claims

1. A method for preparing a landfill odor adsorption system, characterized in that: A landfill odor adsorption system, the system comprising at least one intermediate adsorption subsystem and a topmost closure adsorption subsystem; the intermediate adsorption subsystem is laid as a temporary cover and temporary adsorption after each landfill operation is completed, and is sandwiched inside the garbage body after the next landfill operation. After the landfill operation is completed, the closure adsorption subsystem is laid, and finally a composite structure of "garbage body-intermediate adsorption subsystem...-garbage body-closure adsorption subsystem" is formed, that is, the upper and lower parts of the intermediate adsorption subsystem are the garbage bodies after the landfill operation is completed; the intermediate adsorption subsystem comprises three functional layers, which are an upper gas collection layer, an odor adsorption layer II, and a lower gas collection layer from top to bottom; the The closure adsorption subsystem includes six functional layers, from top to bottom: vegetation layer, drainage layer, anti-seepage layer, drainage layer, odor adsorption layer I, and gas collection layer I; the materials of odor adsorption layer I and odor adsorption layer II are odor adsorption materials, and the raw materials of odor adsorption materials are recycled fine aggregate prepared from recycled construction waste and recycled powder. The recycled construction waste contains quicklime or slaked lime; the proportion of concrete and mortar in the recycled construction waste for preparing recycled fine aggregate and recycled powder is ≥95%, and the strength of the original concrete is not less than C30. The particle size distribution curve of the odor adsorption material is saddle-shaped. Specifically, according to soil mechanics standards, the particle size gradation curve characteristics of the recycled fine material must meet the following conditions: (a) the maximum particle size does not exceed 2mm; (b) the effective particle size d 10 Not more than 0.005mm; (c) 1.2mm≤d 90 ≤1.8mm; (d) Unevenness coefficient CU≥5; (e) Curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C ≥1; The compaction degree of odor adsorption layer I and odor adsorption layer II are ≥95% respectively. Under the maximum dry density, the air permeability coefficient of odor adsorption layer I and odor adsorption layer II are 10 -6 m / s—10 -8 m / s, the air intake values ​​are 1kPa-10kPa, the water absorption rates are ≥10%, and the pore water saturations are 60%-90%; Preparation method of landfill odor adsorption system, The method comprises the following steps: (1) preparing materials according to the raw material requirements of each functional layer, taking the soil material of the vegetation layer from nearby, and taking the recycled materials required for other functional layers from the construction waste buried in the landfill or the construction waste to be buried in the landfill; before preparing the recycled aggregate and recycled powder, removing the impurities of wood, steel bars, and slag from the construction waste, and only retaining the waste concrete and mortar stone; then crushing, grinding and screening to prepare the recycled coarse aggregate and recycled fine aggregate with the corresponding predetermined particle size requirements, preparing the micro powder, i.e. the recycled powder, by using the dust collection equipment, and mixing the micro powder with the recycled fine aggregate to prepare the odor adsorption material; (2) Before constructing the enclosure adsorption subsystem and the intermediate adsorption subsystem, the required materials need to be mixed with water to reach the optimal moisture content, and then sealed and cured to ensure uniform moisture content; (3) Laying of the intermediate adsorption subsystem: After the landfill operation is completed, the landfill is leveled and rolled, and then a layer of geotextile is laid. Then, the compacted coarse aggregate of the lower gas collection layer is laid on the geotextile. The recycled coarse aggregate is laid in layers and fully compacted. The thickness of each layer shall not exceed 10 cm, and the compaction degree shall meet the requirements, not less than 0.9 relative density, and then the geotextile is laid; then, the odor adsorption layer II is laid on the geotextile. When laying, it shall be laid in layers and fully compacted. The thickness of each layer shall not exceed 10 cm, and the compaction degree shall not be less than 95%. After the laying of the attached layer II is completed, the odor adsorption layer II needs to be artificially watered or aired so that its moisture content reaches the predetermined adsorption reaction moisture content. When the next round of garbage landfill operation is carried out, it is only necessary to lay the upper gas collection layer on the odor adsorption layer. The laying method is the same as the lower gas collection layer. First lay the geotextile, then lay the upper gas collection layer on the geotextile, and then landfill the garbage; after the next round of garbage landfill operation is completed, continue to lay the intermediate adsorption subsystem, and then carry out the next round of landfill operation until the predetermined landfill elevation is reached for sealing, and lay the sealing adsorption subsystem; (4) Laying of the closure adsorption subsystem: After the landfill operation is completed, the landfill is cleaned, leveled and rolled, and then a geotextile is laid on the compacted and leveled garbage body. Then, the compacted coarse aggregate of the gas collection layer I is laid on the geotextile. The recycled coarse aggregate is laid in layers and fully compacted. The thickness of each layer does not exceed 10 cm, and the compaction degree meets the requirements. Then, the geotextile is laid, and then the odor adsorption layer I is laid on the geotextile. When laying, it needs to be laid in layers and fully compacted. The thickness of each layer is 10 cm, and the compaction degree does not exceed 10 cm. Lower than 95%. After the odor adsorption layer I is laid, the odor adsorption layer needs to be artificially sprinkled with water or dried in the sun so that its moisture content reaches the predetermined adsorption reaction moisture content. Then lay the geotextile, and lay the drainage layer on the geotextile, and then lay the geotextile, and lay the anti-seepage layer on the geotextile. When laying, it is necessary to lay it in layers and compact it fully. The thickness of each layer shall not exceed 10cm, and the compaction degree shall not be lower than 95%. Then lay the geotextile, and lay the drainage layer on the geotextile, and then lay the geotextile on the drainage layer, and then lay the vegetation layer.

2. The method for preparing the landfill odor adsorption system according to claim 1, characterized in that: The raw materials of the upper and lower gas collection layers are respectively recycled coarse aggregate, which is recycled coarse aggregate prepared by recycling construction waste, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compacted relative density ≥0.9; the thickness of the odor adsorption layer II is 0.3-0.6m.

3. The method for preparing the landfill odor adsorption system according to claim 2, characterized in that: The vegetation layer includes the natural soil at the bottom and the surface nutrient soil above the natural soil. The thickness of the vegetation layer is ≥ 0.5m, and the compaction degree of the vegetation layer soil is greater than or equal to 80%; The raw material of the drainage layer is recycled coarse aggregate made from construction waste, with a thickness of 0.2-0.4m, a particle size of 20-40mm, and a compacted relative density ≥0.9; The raw material of the anti-seepage layer is recycled fine aggregate made from construction waste. The maximum particle size of the recycled fine aggregate is 2 mm, and the effective particle size d 10 Not more than 0.01mm, unevenness coefficient C U ≥5, curvature coefficient C C Between 1 and 3, that is, 3 ≥ C C ≥1, compaction degree not less than 95%, permeability coefficient between 10 -9 m / s -10 -6 m / s, water absorption ≥8%, unsaturated soil mechanical air intake value ≥5kPa; The raw material of the drainage layer is recycled coarse aggregate made from construction waste; the drainage layer thickness is 0.2-0.4m, the particle size is 10-40mm, the compacted relative density is ≥ 0.9, the unsaturated soil mechanical air intake value does not exceed 1 kPa, and the permeability coefficient is ≥ 10 -2 m / s; the difference in air intake value between the recycled fine aggregate of the anti-seepage layer and the recycled coarse aggregate of the drainage layer is ≥4kPa; The thickness of odor adsorption layer I is 0.4-1.0m; the gas collection layer I is located between the odor adsorption layer I and the garbage body of the closure adsorption subsystem, and is constructed with recycled coarse aggregate, with a thickness of 0.3-0.5m, a particle size of 20-40mm, and a compacted relative density of not less than 0.

9.

4. The method for preparing the landfill odor adsorption system according to any one of claims 1 to 3, characterized in that: A water-permeable and air-permeable insulating material layer is provided between each functional layer to prevent the raw materials of each layer from mixing.

5. The method for preparing the landfill odor adsorption system according to claim 3, characterized in that: The strength of the original concrete made from recycled fine aggregate and recycled coarse aggregate from construction waste shall not be less than C10.

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