Household garbage curing construction process based on biological enzyme type soil curing agent

Abstract

The invention discloses a household garbage solidification construction technology based on a biological enzyme type soil solidifying agent, and belongs to the technical field of soil solidification engineering. Comprising the following steps: mixing and stirring bio-enzyme lipidosome, quick lime, cement, premixed flow-state solidified soil and water to form curing agent slurry; a drilling machine is used for drilling a round hole downwards in the domestic waste yard, then the round hole is filled with curing agent grout, the curing agent grout is injected into the round hole, and then clay is covered for sealing to complete the domestic waste curing construction technology. The preparation method comprises the following steps: protecting a biological enzyme by taking Tayase and Pi enzyme as one of biological enzyme curing agent raw materials to prepare a biological enzyme lipidosome with alkali resistance, then mixing the biological enzyme lipidosome with quick lime, cement, premixed flow-state cured soil and water to form curing agent slurry, and performing drilling, grouting and stirring by a cement stirring pile machine to prepare the curing agent. And filling the curing agent slurry into the household garbage landfill soil, curing, and sealing to finish treatment, so as to realize curing utilization of the garbage landfill soil.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil solidification engineering, and particularly relates to a construction process for solidifying domestic waste based on a bio-enzyme type soil solidifying agent. Background Art

[0002] In a broad sense, any material used to reinforce soil should be called a soil solidifying agent. In a narrow sense, a soil solidifying agent refers to a soil hardening agent that can directly cement the surface of soil particles in the soil or react with clay minerals to generate a gelling substance at normal temperature. It can react with various types of soil to become a stable and durable stabilized soil. As a new type of additive for road construction materials, the soil solidifying agent has wide applicability. Practice has proved that the strength of the soil solidified by the solidifying agent is high, the water stability is good, and the anti-drying shrinkage performance is good. After the soil is solidified, it forms a plate body and becomes a semi-rigid road base or sub-base. Its overall mechanical properties are good, which can improve the quality of the road, extend the service life of the road, reduce the project cost, and speed up the construction speed. It is a high-quality road construction material with comprehensive solidifying and stabilizing properties. Municipal domestic waste refers to solid waste generated in urban daily life or in activities providing services for urban daily life. Since the 1980s, with the growth of the urban population and the improvement of living standards, more and more waste has been generated. These wastes not only pollute the environment, damage the urban landscape, but also spread diseases and threaten the safety of human life. How to deal with urban waste has become an important problem that needs to be solved urgently by countries around the world.

[0003] The main methods of garbage disposal are composting, incineration and landfill. Composting is to make the organic matter in the garbage undergo biochemical reactions under the action of microorganisms, and finally form a substance similar to humus soil, which can be used as fertilizer or soil conditioner. A complete set of machinery is used for composting operations in foreign countries, and my country has also piloted it. However, due to the complex composition of garbage in my country, high inorganic content, and low composting effect, this technology has not been widely promoted in China. Incineration is a method in which the combustible components in the garbage undergo combustion reactions under high temperature (800℃~1000℃) conditions to fully oxidize the combustible components and eventually become harmless and stable ash, and recover heat energy for heating and power generation. Sweden, Japan and other countries have used garbage incineration as a way to develop new energy. my country's urban garbage has mixed components and low calorific value (about 300~400 kcal), and the incineration method has large investment, complex management, high processing costs and high pollution, which has led to the fact that this technology has not been widely promoted and applied in China. At present, the most widely used method of garbage disposal is to build a landfill to bury the garbage. The construction of early landfills was relatively random. Landfills were similar to simple garbage dumps, which caused great pollution to the surrounding environment. Now, the construction of sanitary landfills for urban domestic waste has become a development trend of garbage disposal. In the construction process of sanitary landfills for urban domestic waste, the most important goal is to isolate the garbage from the surrounding environment. The landfill method is to send the garbage to a selected landfill site, spread and compact it in a limited area with a specific range of thickness of each layer, and then cover and compact it with soil after daily operation. The garbage layer and the soil cover layer together constitute a filling unit, and a complete landfill is composed of several filling units. When the garbage pile in the landfill reaches the final design height, it is necessary to cover the landfill layer with special requirements of clay, and then cover the ordinary soil layer and compact it, and finally form a closed and hygienic landfill system. Landfill method has large waste treatment capacity, simple treatment technology, no need for pre-treatment of waste, convenient management, reasonable operating costs, and is the final treatment method for urban waste. It has been widely used in many countries in the world and is currently the most common waste treatment method. In my country, landfill method has gradually become the main method of waste treatment, and many cities have built landfills.

[0004] Landfills, as a way of solid waste treatment, can effectively handle garbage in the short term. However, their long-term existence may bring various hazards and problems. The following are some of the main hazards of landfills: (1) Environmental pollution: Hazardous substances in landfills, such as heavy metals, chemical substances, and organic pollutants, may seep into the soil, affecting the quality and function of the soil; the leachate of landfill waste may pollute groundwater and surface water, resulting in water source pollution and affecting drinking water safety; garbage may release some volatile organic compounds (VOCs) and odors during the landfill process, leading to a decline in air quality and affecting the health of surrounding residents. (2) Health risks: Harmful gases (such as methane, ammonia, etc.) emitted by landfills may affect the respiratory systems of surrounding residents, causing respiratory diseases; Spread of infectious diseases: Landfills may become breeding grounds for pathogens, increasing the risk of disease transmission, especially in summer and humid environments. (3) Ecological impacts: Loss of biodiversity: Constructing landfills usually requires occupying land, resulting in the destruction of ecological habitats and affecting local plant and animal populations; Disruption of ecosystems: The existence of landfills may affect the ecological balance of the surrounding area, causing losses in ecological functions. (4) Waste of land resources: Landfills require a large amount of land resources, occupying available land for a long time and restricting its subsequent use, such as agriculture and urban development. (5) Economic costs: The pollution of landfills requires later treatment and restoration, which may lead to high economic costs, including the expenses for cleaning, treating pollution, and restoring the land. The hazards of landfills are multi-faceted, involving the fields of environment, health, ecology, and social economy. Therefore, in waste management, in addition to landfilling, attention should also be paid to the resource utilization of landfills after landfill to maximize the reduction of the negative impacts of landfill sites and improve the resource value of landfill sites.

[0005] Transforming landfill sites into engineered stabilized soil is a novel and innovative way of resource utilization, with multiple benefits: (1) Environmental protection: Converting the waste in landfills into engineered stabilized soil can effectively reduce the amount of solid waste landfilled and relieve the burden on landfills; through the stabilization process, the risk of pollution to the surrounding soil and water sources by landfills can be reduced, especially the leaching of heavy metals and harmful substances. (2) Resource reuse: Converting waste into engineering materials conforms to the concept of circular economy and helps to efficiently utilize resources; using engineered stabilized soil can reduce the demand for traditional building materials (such as sand and stone), saving natural resources. (3) Economic benefits: Using stabilized soil as a building material can reduce the material costs of road construction; the production and treatment of stabilized soil can drive the development of related industries and create new job opportunities. (4) Improvement of soil properties: Stabilized soil usually has high strength and stability, which can improve the bearing capacity and durability of roads; the stabilization process can improve the drainage performance of stabilized soil and reduce the risk of road waterlogging and soil erosion. (5) Technological innovation: The development of stabilization technology can promote the research and application of new building materials and engineering technologies, and drive the technological progress of the construction industry. (6) Social benefits: Converting waste into usable engineering materials can enhance the environmental image of the city and increase the public's awareness of sustainable development; by reducing the area and pollution of landfills, the living environment of surrounding communities and the health of residents can be improved.

[0006] Due to the complexity of landfill sites, with diverse waste components and the characteristic that organic matter gradually degrades over time, the settlement and deformation process of landfills is long and difficult to predict. The engineering mechanical properties of waste soil are poor, with low shear strength and high compressibility. After rotting and forming cavities, its self-bearing capacity is low and it cannot be directly used for engineering construction sites. Research at home and abroad shows that: the settlement of the landfill body after capping generally lasts for several decades, and the total settlement is about 25% - 50% of the initial landfill height; the settlement caused by the degradation of organic matter may reach 18% - 24% of the total height of the landfill. Moreover, due to the unique properties of domestic waste after landfill (such as large voids, complex composition, and no soil structure), its reinforcement method is very different from that of traditional loose soil and silt. Affected by various factors, it is difficult to solidify the sites of urban domestic waste landfills through conventional solidification methods, and thus it cannot be applied to engineering construction sites.

[0007] Therefore, how to achieve the solidification and utilization of urban landfill sites is a huge challenge. Summary of the Invention

[0008] In view of the deficiencies of the prior art, the present invention uses teranenzyme and perenzyme as one of the raw materials for the bioenzyme curing agent, protects the bioenzyme to prepare bioenzyme liposomes with alkali resistance performance, and then mixes them with quicklime, cement, premixed flowing solidified soil and water to form a curing agent slurry. By means of drilling and grouting and mixing with a cement mixing pile machine, the curing agent slurry is filled into the domestic waste landfill soil, and after curing, the sealing layer is completed, thus solving the technical problems raised in the background art. Specifically, the technical solution of the present invention includes the following contents:

[0009] A domestic waste solidification construction process based on a bioenzyme-type soil curing agent, the domestic waste solidification construction process comprising the following steps:

[0010] Mix bioenzyme liposomes, quicklime, cement, premixed flowing solidified soil and water in a weight ratio of 0.01:1:2:1.5:5 and stir to form a curing agent slurry;

[0011] Use a drilling machine to drill a circular hole with a depth of 13.5 meters downward in the domestic waste site, then fill and grout the curing agent slurry into the circular hole, and then cover it with clay for sealing to complete the domestic waste solidification construction process.

[0012] Further, the preparation method of the bioenzyme liposomes includes the following steps:

[0013] Mix the mixed enzyme, cholesterol, soybean lecithin and absolute ethanol to form an oil phase. After mixing the oil phase and the water phase and stirring at a speed of 400 r / min for 40 min, the bioenzyme liposomes are obtained through filtration.

[0014] Further, the mixed enzyme is composed of teranenzyme and perenzyme mixed in a mass ratio of 1:1.

[0015] Further, the mass ratio of the mixed enzyme: perenzyme: cholesterol: soybean lecithin: absolute ethanol is 1:2:9:1000.

[0016] Further, the water phase is composed of deionized water.

[0017] Further, the weight ratio of the oil phase to the water phase is 1:3.

[0018] Furthermore, the strength grade of the cement is P.O42.5R.

[0019] Further, the preparation method of the premixed flowing solidified soil includes the following steps:

[0020] Mix the curing agent, admixture, water and soil materials in a weight ratio of 10:1:20:69 in a mixer and stir to form the premixed flowing solidified soil.

[0021] Further, the curing agent is limestone.

[0022] Further, the admixture is a polycarboxylate superplasticizer.

[0023] Further, the soil material can be the soil material obtained by conventional trench excavation or other construction waste soil materials.

[0024] Further, the usage amount of the curing agent slurry is 0.67 cubic meters of the curing agent slurry per cubic meter of domestic waste filled.

[0025] Further, the number of times of filling and grouting is 2 times.

[0026] Further, the thickness of the covering clay for sealing is 2 m.

[0027] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0028] The Tairan enzyme and Pai enzyme used in the present invention can make the soil fungi more active, release hydrogen ions, and form a pH value gradient on the surface of soil particles, which is beneficial to changing the original soil structure and thus improving the anti-seepage performance of the soil mass. A large number of organic molecules in the soil particles combine with the bio-enzyme to form an intermediate reaction enzyme, which is then adsorbed by clay ions and replaces them, causing the double electric layer structure of the clay to break, thereby reducing the hydrophilicity of the soil particles and forming a waterproof soil layer. After compaction, the soil loses the ability to absorb water again, and the mechanical effect of the soil mass will not be affected even when it encounters water again. At the same time, the bio-enzyme liposome has an adsorption effect on the viscous mineral particles in the soil, binding the particles of different sizes in the soil body together. The number of large pores in the soil decreases, and the number of small pores increases, improving the cohesion degree and enhancing the interaction force between the soil particles. Quicklime is used as a desiccant because its dehumidification function is very strong and it can react with the moisture in the air. At the same time, after quicklime enters the soil, it will also generate a certain amount of heat, which can achieve effective sterilization and disinfection. Premixed flowing solidified soil makes full use of the soil materials after the excavation of the fat groove, foundation pit or waste, and then mixes in a certain proportion of soil curing agent, admixture and water, and fully mixes them evenly by machinery to form a pumpable and fluid reinforcement material. The fluidity of the premixed flowing solidified soil can fill all the voids in narrow spaces and special-shaped structure spaces. The premixed flowing solidified soil has the characteristics of self-compaction. During construction, large-scale ramming and rolling equipment do not need to be used for compaction, solving the problem that construction cannot be carried out in some narrow spaces. At the same time, the premixed flowing solidified soil adopts the construction method of mechanical premixing, centralized mixing and on-site pouring. The premixed flowing solidified soil is evenly mixed and has stable quality, and the on-site pouring is less affected by on-site conditions and construction personnel factors. However, due to the strong alkalinity of quicklime and the heat generated after contact with water, it is easy to cause the Tairan enzyme and Pai enzyme to lose their activity. Therefore, in the present invention, the Tairan enzyme, Pai enzyme, soybean lecithin, absolute ethanol and cholesterol are mixed to form an oil phase, and then the oil phase and the water phase are mixed and stirred to obtain a bio-enzyme liposome to protect the Tairan enzyme and Pai enzyme. The curing agent slurry is formed by mixing the bio-enzyme liposome, quicklime, cement, premixed flowing solidified soil and water. By means of drilling, grouting and stirring with a cement mixing pile machine, the curing agent slurry is filled into the domestic waste landfill soil, and the treatment is completed after curing, realizing the solidification and utilization of the landfill site. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a result diagram of the domestic waste site after solidification treatment in Example 1.

[0030] Figure 2 It is a result diagram of the domestic waste site after solidification treatment in Comparative Example 1.

[0031] Figure 3 It is a result diagram of the domestic waste site after solidification treatment in Comparative Example 2. Detailed implementation manners

[0032] The technical solutions of the present invention will be clearly and completely described below through embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts belong to the scope of protection of the present invention.

[0033] Unless otherwise specified, the raw materials and reagents used in the present invention below are all commercially available products or can be prepared by known methods.

[0034] Preparation Example 1:

[0035] The preparation of bioenzyme liposomes specifically includes the following process:

[0036] Weigh 3 mg of Terrazyme, 3 mg of Permazyme, 12 mg of cholesterol and 54 mg of soybean lecithin and put them into a flask, then add 6 g of absolute ethanol, mix and place in a water bath at a water bath temperature of 45 ± 1 °C until all are dissolved and mixed evenly to obtain an oil phase and keep it warm;

[0037] Take 25 g of deionized water and add it to a new flask, heat it to 55 °C to obtain an aqueous phase and keep it warm;

[0038] Subsequently, according to the weight ratio of the oil phase to the water phase of 1:3, the oil phase is all dropped into the water phase at 55 °C, and stirred at a speed of 400 r / min for 40 min. After the stirring is completed, the obtained mixture is placed on a rotary evaporator to rotary evaporate to remove absolute ethanol, and then filtered through a 0.22 μm filter membrane to obtain bioenzyme liposomes, which are placed in a refrigerator at 4 °C for storage and use.

[0039] Preparation Example 2:

[0040] The preparation of premixed flowable solidified soil specifically includes the following process:

[0041] Mix 10 parts by weight of limestone, 1 part by weight of admixture Polycarboxylate superplasticizer, 20 parts by weight of water and 69 parts by weight of soil material and place them in a mixer, start stirring for blending to form premixed flowable solidified soil.

[0042] Example 1:

[0043] A domestic waste solidification construction process based on a bioenzyme soil stabilizer specifically includes the following process:

[0044] Take 1 part by weight of the bio-enzyme liposome obtained in Preparation Example 1, 100 parts by weight of quicklime, 200 parts by weight of cement, 150 parts by weight of the premixed flowing solidified soil obtained in Preparation Example 2, and 500 parts by weight of water, and mix and stir to form a curing agent slurry;

[0045] Use a drilling machine to drill multiple round holes with a depth of 13.5 meters downward in the domestic waste site. Subsequently, according to the grouting volume of 0.67 cubic meters of the curing agent slurry filled per cubic meter of domestic waste, grout the curing agent slurry into the round holes so that the slurry is in full contact with the soil part. Through physical extrusion, the curing agent slurry and the domestic waste form a tight combination. The number of grouting passes is 2 times, and then cover with 2 m thickness of clay for sealing to complete the domestic waste solidification construction process.

[0046] Comparative Example 1:

[0047] A domestic waste solidification construction process specifically includes the following steps:

[0048] Replace the curing agent slurry in Example 1 with a mixture of cement, fly ash, soil and water (cement, fly ash, soil and water are mixed and added according to the weight ratio of 2:1:5:1). Then, after using a drill to drill the grouting pipe with a nozzle to a predetermined position (a depth of 13.5 meters), according to the grouting volume of 0.55 cubic meters of the curing agent slurry filled per cubic meter of domestic waste, use a high-pressure device to process the curing agent slurry into a high-pressure flow and spray it out from the nozzle, impact and break the soil body, stir and mix with the soil body to form a high-density concrete pile body, and complete the domestic waste solidification construction process.

[0049] Comparative Example 2:

[0050] A domestic waste solidification construction process specifically includes the following steps:

[0051] Replace the bio-enzyme liposome in Example 1 with pepsin and terramycin (the two are used in equal amounts), and then set the grouting volume to 0.5 cubic meters of the curing agent slurry filled per cubic meter of domestic waste, and the other conditions are the same as those in Example 1.

[0052] On the 7th day after grouting, conduct on-site inspection and take pictures of the domestic waste site after solidification treatment. The graphical results are shown in Figures 1 to 3 , Figure 1 is the result diagram of the domestic waste site after solidification treatment in Example 1, Figure 2 is the result diagram of the domestic waste site after solidification treatment in Comparative Example 1, Figure 3 is the result diagram of the domestic waste site after solidification treatment in Comparative Example 2. Through on-site inspection, it is found that:

[0053] There is no stench and no flies in the domestic waste site after solidification treatment in Example 1. From Figure 1It can be seen that the garbage is fragmented, has a good wrapping effect, and the solidified material is evenly and fully filled. The results of this test show that the combination of bioenzyme liposomes, quicklime, cement, premixed fluidized solidified soil, and water has a better effect in disinfecting organic matter, and the garbage is basically fragmented.

[0054] In the domestic waste site after solidification treatment in Comparative Example 1, there was a foul smell and flies flying. From Figure 2 it can be seen that the garbage is basically not wrapped with solidified materials, the soil bearing capacity is low, and the distribution of the solidifying agent is uneven, so the solidification effect cannot be achieved, and finally the leaching detection of toxic substance content, the physical permeability coefficient test, and the foundation bearing capacity test cannot be completed.

[0055] In the domestic waste site after solidification treatment in Comparative Example 2, there was basically no foul smell or flies. From Figure 3 it can be seen that the wrapping effect of the garbage is good, but the local filling is not full, and the better solidification effect cannot be achieved. Finally, the leaching detection of toxic substance content, the physical permeability coefficient test, and the foundation bearing capacity test cannot be completed.

[0056] On the 7th day after grouting, the toxic substance content of the solidified soil block after construction and solidification in Example 1 was detected, and the results are shown in Table 1.

[0057] Table 1 Detection results of toxic substance content

[0058]

[0059] On the 7th day and the 28th day after grouting, the physical permeability coefficient of the solidified soil block after construction and solidification in Example 1 was tested, and the results are shown in Table 2.

[0060] Table 2 Test results of physical permeability coefficient

[0061] Days after forming by grouting Test value (cm / s) Index requirement (cm / s) Whether it meets the requirement The 7th day <![CDATA[2.75×10 -6 > <![CDATA[≤1×10 -7 > Does not meet the requirement The 28th day <![CDATA[2.88×10 -7 > <![CDATA[≤1×10 -7 > Meets the requirement

[0062] On the 14th day and the 28th day after grouting, three places were sampled from the solidified soil block after construction and solidification in Example 1 for test numbers, and then the plate load test was carried out. The results are shown in Table 3.

[0063] Table 3 Test results of plate load

[0064]

[0065] It can be seen from Table 3 that;

[0066] (1) The total load of the three test points (Y1 - Y3) after 14 days of solidification was 360 kPa, the settlement was small, and there was no obvious lateral extrusion or uplift of the soil around the loading plate. The characteristic value of the foundation soil bearing capacity within the influence depth of the loading plate at the three test points was fak = 180 kPa. The characteristic value of the foundation bearing capacity after 14 days of solidification meets the design requirement of 180 kPa.

[0067] (2) The total loading of the three test points (Y4 - Y6) after 28 days of curing is 640 kPa, the settlement is small, and there is no obvious lateral extrusion or heave of the soil around the loading plate. The characteristic value of the bearing capacity of the foundation soil within the influence depth range of the loading plate at the three test points is fak = 320 kPa. The characteristic value of the bearing capacity of the foundation after 28 days of curing meets the design requirement of 320 kPa.

[0068] The above - described embodiments have detailed the technical solutions and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Without departing from the spirit and scope of the present invention, the present invention will have various changes and improvements, and these changes and improvements all fall within the scope of the present invention claimed.

Claims

1. A domestic waste solidification construction process based on a bio-enzyme soil solidifier, characterized in that: The domestic waste solidification construction process comprises the following steps: The bio-enzyme liposome, quicklime, cement, premixed fluidized solidified soil and water are mixed and stirred in a weight ratio of 0.01:1:2:1.5:5 to form a curing agent slurry; A circular hole with a depth of 13.5 meters is drilled downward in the domestic waste site using a drilling machine, and then the curing agent slurry is filled and grouted into the circular hole, which is then covered with clay for sealing to complete the domestic waste solidification construction process.

2. According to claim 1, a domestic waste solidification construction process based on a biological enzyme type soil solidifier is characterized in that: The preparation method of the bioenzyme liposome comprises the following steps: The mixed enzyme, cholesterol, soybean lecithin and anhydrous ethanol are mixed to form an oil phase, the oil phase and the water phase are mixed and stirred at a speed of 400 r / min for 40 minutes, and then filtered to obtain the bio-enzyme liposome.

3. According to claim 2, a domestic waste solidification construction process based on a biological enzyme type soil solidifier is characterized in that: The mixed enzyme is composed of Tairanase and Paiase mixed in a mass ratio of 1:

1.

4. According to claim 2, a domestic waste solidification construction process based on a biological enzyme type soil solidifier is characterized in that: The mass ratio of the mixed enzyme: Paezyme: cholesterol: soybean lecithin: anhydrous ethanol is 1:2:9:1000.

5. According to claim 2, a domestic waste solidification construction process based on a biological enzyme type soil solidifier is characterized in that: The weight ratio of the oil phase to the water phase is 1:

3.

6. According to claim 1, a domestic waste solidification construction process based on a biological enzyme type soil solidifier is characterized in that: The preparation method of the premixed fluidized solidified soil comprises the following steps: The curing agent, admixture, water and soil material are mixed in a mixer according to a weight ratio of 10:1:20:69 to form the premixed fluidized solidified soil.

7. A domestic waste solidification construction process based on a biological enzyme type soil solidifier according to claim 6, characterized in that: The curing agent is limestone.

8. A domestic waste solidification construction process based on a biological enzyme type soil solidifier according to claim 6, characterized in that: The admixture is -ⅠPolycarboxylic acid high performance water reducing agent.

9. A domestic waste solidification construction process based on a biological enzyme type soil solidifier according to claim 1, characterized in that: The usage amount of the curing agent slurry is 0.67 cubic meters of curing agent slurry per cubic meter of domestic waste site.

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