Solidified materials with both seepage prevention and pollution remediation functions and their applications

Abstract

This invention relates to the field of solidification materials, and discloses a solidification material that combines seepage prevention and pollution remediation functions with its application. The solidification material comprises a first component, a second component, and a third component; the first component comprises cement; the second component comprises slag; and the third component comprises hydrotalcite and a piezoelectric catalyst. Through the rational matching and compounding of its components, this solidification material forms a synergistic effect, significantly improving the crack resistance, seepage resistance, and corrosion resistance of vertical seepage barriers. It can simultaneously meet the requirements for seepage prevention performance and has the function of remediating heavy metals and organic pollution, thereby achieving the goal of long-term vertical seepage prevention in solid waste dumps. Furthermore, it simultaneously realizes the reduction and utilization of bulk solid wastes such as blast furnace slag and fly ash, resulting in excellent economic and equipment benefits.

Description

Technical Field

[0001] This invention relates to the field of curing materials, specifically to curing materials that combine seepage prevention and pollution remediation functions, and their applications. Background Technology

[0002] With the continuous improvement of my country's economic and industrial levels, the generation of general industrial solid waste has also increased rapidly. The number of industrial solid waste dumps is enormous, and the types are diverse, with very few ways to comprehensively utilize them. Currently, my country mainly uses stockpiling and disposal methods to treat most industrial solid waste. The management effectiveness of these stockpiles directly affects the treatment effect of industrial solid waste, and strengthening the management of industrial solid waste stockpiles can reduce soil pollution.

[0003] For these large quantities of existing solid waste, on-site management is a practical solution. Vertical barriers (anti-seepage walls) should be erected around the solid waste dump or at a certain depth downstream of the groundwater flow to prevent contaminated water from spreading and migrating to other water bodies and polluting the surrounding waters. Currently, the most commonly used anti-seepage technologies for solid waste landfills are those introduced from industries such as water conservancy, metallurgy, and mining. These concrete underground barrier walls in water conservancy and civil engineering projects typically utilize uncontaminated groundwater as the environmental fluid, with the strength of the concrete being the primary consideration.

[0004] Solid waste disposal sites need to contain contaminated groundwater, which often has high concentrations of pollutants and exhibits varying acidity, alkalinity, and salinity, as well as containing various heavy metals and organic matter. With increasing social development and a growing emphasis on environmental protection, especially in industries such as mineral resource recycling, environmental remediation, and hazardous waste disposal, there is an urgent need for a barrier material that meets both seepage prevention requirements and environmental remediation functions.

[0005] CN111548089A discloses a barrier material with environmental remediation function, as well as its preparation and application method. The barrier material, by weight, comprises the following raw materials: 50-300 parts soft clay, 50-200 parts bentonite, 50-300 parts water-based resin emulsion, 10-300 parts dry powder, 10-50 parts activated carbon powder, and 10-40 parts iron powder; the dry powder is one or more of ordinary cement, quick-drying cement, and fly ash. This material exhibits good impermeability and can remediate heavy metals. In application, it can achieve both seepage prevention and heavy metal remediation functions in a single construction, reducing construction difficulty and cost, and shortening the corresponding construction cycle. This patent application mainly focuses on seepage prevention and heavy metal remediation, but does not consider the degradation of organic matter.

[0006] The seepage from solid waste dumps is often a complex pollution source, involving multiple heavy metals and organic pollutants. Therefore, for groundwater contamination prevention technology in solid waste dumps, it is particularly important to develop a barrier material that can remediate heavy metal and organic pollution while also meeting the seepage prevention requirements of seepage control projects. Summary of the Invention

[0007] The purpose of this invention is to overcome the aforementioned problems in the existing technology and provide a solidification material and its application that combines seepage prevention and pollution remediation functions. This solidification material, through the rational matching and compounding of various materials such as cement, slag, hydrotalcite, and piezoelectric catalysts, forms a synergistic effect, which can significantly improve the crack resistance, seepage resistance, and corrosion resistance of vertical seepage prevention and barrier. It can simultaneously meet the requirements of seepage prevention performance and has the function of remediation of heavy metals and organic pollution, thereby achieving the purpose of long-term vertical seepage prevention and barrier in solid waste dumps. At the same time, it also realizes the reduction and utilization of bulk solid wastes such as blast furnace slag and fly ash, which has good economic and equipment benefits.

[0008] To achieve the above objectives, the first aspect of the present invention provides a curing material that combines seepage prevention and pollution remediation functions, the curing material comprising a first component, a second component, and a third component;

[0009] The first component includes cement;

[0010] The second component includes slag;

[0011] The third component includes hydrotalcite and a piezoelectric catalyst.

[0012] A second aspect of the present invention provides a method for constructing a barrier wall for a solid waste disposal site, the method comprising: mixing the above-mentioned solidified material with water and then constructing the wall.

[0013] A third aspect of the present invention provides the application of the above-mentioned solidified material in the vertical seepage prevention barrier of a composite polluted solid waste dump.

[0014] Through the above technical solution, the present invention has at least the following beneficial effects:

[0015] (1) The curing material provided by the present invention, through the reasonable matching and compounding of the first, second and third components, forms a cross-superimposed effect, which can significantly improve the crack resistance, seepage resistance and corrosion resistance of the vertical seepage barrier wall, providing dual functions of barrier and repair, and avoiding its adverse impact on the surrounding environment. Preferably, by changing the proportion of each component, the strength, seepage resistance and sulfate resistance of the vertical seepage barrier wall can be more effectively controlled, and the method of use is simple and easy to operate.

[0016] (2) The solidification material provided by the present invention uses bulk industrial solid waste such as blast furnace slag and fly ash, which is inexpensive and effectively solves the problem of reducing the utilization of bulk solid waste. It also reduces the cost of vertical seepage prevention and barrier, and effectively protects the environment. Detailed Implementation

[0017] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0018] The first aspect of the present invention provides a curing material that combines seepage prevention and pollution remediation functions, characterized in that the curing material comprises a first component, a second component, and a third component;

[0019] The first component includes cement;

[0020] The second component includes slag;

[0021] The third component includes hydrotalcite and a piezoelectric catalyst.

[0022] The inventors of this invention have discovered that adding hydrotalcite to the curing material of this application, in combination with cement and slag, can not only enhance the crack resistance and impermeability of the curing material, but also reduce the intrusion and corrosion of pollutants such as heavy metal cations and sulfate anions.

[0023] The inventors of this invention have discovered that adding a piezoelectric catalyst to the curing material of this invention, when combined with cement and slag, can not only enhance the crack resistance and impermeability of the curing material, but also reduce / oxidize heavy metals and oxidize and degrade organic pollutants.

[0024] Preferably, the weight ratio of the first component to the third component is 5-80:1, and can be 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, 55:1, 60:1, 65:1, 70:1, 75:1, 80:1, or any range formed by any two of the above values. The weight ratio of the second component to the third component is 2-50:1, and can be 2:1, 5:1, 10:1, 15:1, 20:1, 25:1, 30:1, 35:1, 40:1, 45:1, 50:1, or any range formed by any two of the above values.

[0025] The inventors of this invention have discovered that combining hydrotalcite with a piezoelectric catalyst can further improve the crack resistance and impermeability of the cured material, and can also reduce / oxidize heavy metals and oxidize and degrade organic pollutants, thereby reducing the intrusion and corrosion of pollutants such as heavy metal cations and sulfate anions.

[0026] In this invention, in order to further improve the crack resistance and impermeability of the cured material, it can also reduce / oxidize heavy metals and oxidize and degrade organic pollutants, reduce the intrusion and corrosion of pollutants such as heavy metal cations and sulfate anions. The weight ratio of the hydrotalcite and the piezoelectric catalyst is 1-5:1, which can be 1:1, 2:1, 3:1, 4:1, 5:1 or any two of the above values ​​within the range and values ​​within the range.

[0027] In this invention, the cement is not limited; it can be combined with the second and third components to obtain high crack resistance and impermeability. The cement is a general-purpose cement, specifically classified as silicate cement, ordinary silicate cement, slag silicate cement, pozzolanic silicate cement, fly ash silicate cement, and composite silicate cement. The cement in this invention is preferably silicate cement and / or ordinary silicate cement. More preferably, according to standard GB175-2007, the strength grade of the cement is greater than 42 and less than 63. Even more preferably, the strength grade of the cement is at least one of 42.5, 52.5, and 62.5, with 42.5 being the most preferred.

[0028] In this invention, the slag is not limited and can be used to fill the pores between cement and the third component to achieve micro-aggregate composite superposition and obtain low permeability. Preferably, the slag includes blast furnace slag and / or fly ash.

[0029] In this invention, the blast furnace slag is a waste residue discharged from the blast furnace during pig iron smelting, including at least one of steelmaking pig iron slag, foundry pig iron slag, and manganese iron ore slag. Its main components include oxides of calcium, silicon, aluminum, magnesium, and iron, as well as sulfur. The content of calcium oxide is 32-49% by weight, silicon oxide is 32-41% by weight, aluminum oxide is 6-17% by weight, magnesium oxide is 2-13% by weight, iron oxide is 0.2-4% by weight, and sulfur is 0.2-2% by weight. Preferably, CaO, SiO2, and Al2O3 account for more than 90% by weight.

[0030] In this invention, the main components of the fly ash include oxides of silicon, aluminum, iron, calcium, magnesium, sulfur, and carbon, wherein the SiO2 content is 33.9-59.7 wt%, the Al2O3 content is 16.5-35.4 wt%, the Fe2O3 content is 1.5-19.7 wt%, the CaO content is 0.8-10.4 wt%, the MgO content is 0.7-1.9 wt%, the SO2 content is less than 0.5%, and the C content is 10-20 wt%.

[0031] In this invention, in order to further enable the second component and other components to fill the pores between each other and achieve micro-aggregate composite superposition to obtain lower permeability, the particle size distribution D90 of the second component is 0.005-0.1 mm, that is, 90% of the second component particles are smaller than 0.005-0.1 mm. It can be 0.005 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm or any two of the above values ​​or values ​​within the range, more preferably 0.01-0.05 mm.

[0032] The inventors of this invention have discovered that when the second component is a combination of blast furnace slag and fly ash, better results can be obtained. Preferably, the blast furnace slag accounts for 30-50% of the total weight of the second component, which can be 30%, 35%, 40%, 45%, 50%, or any two of the above values ​​within a range; the fly ash accounts for 50-70% of the total weight of the second component, which can be 50%, 55%, 60%, 65%, 70%, or any two of the above values ​​within a range.

[0033] Preferably, the particle size distribution D90 of the third component is 0.005-0.1 mm, that is, 90% of the second component particles are smaller than 0.005-0.1 mm. It can be 0.005 mm, 0.01 mm, 0.02 mm, 0.03 mm, 0.04 mm, 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm or any two of the above values ​​or values ​​within the range, more preferably 0.01-0.05 mm.

[0034] In this invention, to achieve better results, the hydrotalcite includes at least one of magnesium aluminum hydrotalcite, rare earth hydrotalcite, magnesium zinc aluminum hydrotalcite, and zinc aluminum hydrotalcite.

[0035] In this invention, to achieve better results, the piezoelectric catalyst includes at least one of lead zirconate titanate, bismuth oxychloride, barium titanate, zinc oxide, molybdenum sulfide, and molybdenum selenide.

[0036] The second aspect of the present invention provides a method for constructing a barrier wall for a solid waste disposal site, the method comprising: mixing the above-mentioned solidified material with water and then constructing the wall.

[0037] Preferably, the weight ratio of the curing material to water is 0.6-1.2:1, which can be 0.6:1, 0.7:1, 0.8:1, 0.9:1, 1:1, 1.1:1, 1.2:1 or any two of the above values ​​within a range, preferably 0.8-1:1.

[0038] A third aspect of this invention provides the application of the aforementioned solidification material in vertical seepage prevention barriers for compound contaminated solid waste dumps. Compound contaminated solid waste refers to waste simultaneously contaminated with heavy metals (such as Cr). 6+ Cd 2+ Pb 2+ Hg 2+ Especially Cr 6+ Solid waste contaminated with organic matter (such as benzene compounds, especially benzo[a]pyrene).

[0039] In this invention, the vertical seepage prevention involves constructing a vertical barrier (seepage barrier wall) at a certain depth (usually 2-10m) around the solid waste dump or downstream of the groundwater flow to prevent contaminated water from spreading and migrating to other water bodies and polluting the surrounding waters. The vertical seepage prevention and solidification material proposed in this invention has better seepage resistance and sulfate corrosion resistance than existing solidification materials, and also possesses good compressive strength, while simultaneously having the function of remediating heavy metal and organic pollution.

[0040] The present invention will be described in detail below through examples. In the following examples, the determination of hexavalent chromium is carried out in accordance with the spectrophotometric method of diphenylcarbazide GBT 7467-1987;

[0041] The determination of benzene series compounds shall be performed in accordance with gas chromatography GB / T 11890-1989;

[0042] Concrete sulfate wet-dry cycle test chamber (where the test solution is a salt solution prepared by mixing 95% by weight distilled water and 5% by weight NaSO4 by mass ratio) Source: Beijing Yichuang Times Technology Co., Ltd.;

[0043] Ordinary Portland cement (model PI42.5): Zhengzhou Kanghui Refractory Materials Co., Ltd.;

[0044] Magnesium aluminum hydrotalcite source: Shandong Yousuo Chemical Technology Co., Ltd.;

[0045] Reference for the preparation of magnesium zinc aluminum hydrotalcite: Chen Liqian, Han Bing, Liu Qi, Synthesis and characterization of magnesium aluminum and magnesium zinc aluminum hydrotalcite, Inorganic Salts Industry, 2011, 43(12), 38-41;

[0046] Reference for the preparation of zinc-aluminum hydrotalcite: Zhao Yu, Yang Yubin, Xu Bing, Yu Yue, Li Zhuxin, Chi Liping, Synthesis and electrochemical properties of zinc-aluminum hydrotalcite materials, Journal of Dalian Jiaotong University, 2018, 39(05), 48-52.

[0047] Reference for the preparation of rare earth hydrotalcite: Zhu Hongtao, Li Yanna, Zhai Qiuyue, Guo Ningyu, Preparation and performance study of rare earth element hydrotalcite, Henan Chemical Industry, 2019, 36(07), 15-18.

[0048] Breccia: Shandong Yousuo Chemical Technology Co., Ltd.;

[0049] Piezoelectric catalyst (lead zirconate titanate, bismuth oxychloride, barium titanate, molybdenum sulfide, and quartz crystal) Source: Weifang Bofa Electronic Technology Co., Ltd.;

[0050] Blast furnace slag source: Shijiazhuang Anbai Mining Co., Ltd., main components are as follows:

[0051] CaO is 38.5% by weight, SiO2 is 35.5% by weight, Al2O3 is 15.2% by weight, MgO is 4.6% by weight, Fe2O3 is 3.1% by weight, S is 1.2% by weight, and others are 1.9% by weight.

[0052] Fly ash source: Shijiazhuang Anbai Mining Co., Ltd., main components are as follows:

[0053] The composition is 47.8 wt% SiO2, 27.2 wt% Al2O3, 7.5 wt% Fe2O3, 3.1 wt% CaO, 0.15 wt% MgO, and 14.25 wt% C.

[0054] Water absorption rate: The test blocks were taken out under different corrosion ages and curing environments, and the water on the surface of the test blocks was wiped dry with a clean dry cloth. After drying in an oven at 80℃ for 24 hours, the test blocks were taken out and weighed and recorded as m1. The dried test blocks were soaked in clean water for 24 hours (the water level should be at least 30 mm above the test blocks, and the test blocks should not touch or be stacked). The test blocks were taken out of the clean water, the water on the surface was wiped dry with a dry cloth, and the water absorption rate Wa of the test blocks was recorded as m2. The water absorption rate Wa of the test blocks was calculated by the following formula (accurate to 0.01%): the arithmetic mean of three measurements was taken as the test result.

[0055]

[0056] Concrete compressive strength: Tested according to the "Standard for Test Methods of Mechanical Properties of Ordinary Concrete" (GB / T50081-2002).

[0057] Permeability: The permeability of concrete is determined according to the NEL rapid test method in the "Guideline for Durability Design and Construction of Concrete Structures". e represents ×10.

[0058] Example 1

[0059] Solidification materials: Component 1: 50 parts by weight of ordinary Portland cement; Component 2: 40 parts by weight of slag, of which blast furnace slag accounts for 30 parts by weight and fly ash accounts for 70 parts by weight, with a particle size D90 of 0.1 mm; Component 3: 10 parts by weight, of which magnesium aluminum hydrotalcite and lead zirconate titanate are in a mass ratio of 1:1, with a particle size D90 of 0.05 mm.

[0060] A seepage-proof grout was prepared by mixing water and curing material at a mass ratio of 0.8:1. The prepared grout was then injected in situ to create a vertical seepage-proof barrier wall. Core samples were taken to test the performance of the vertical seepage-proof barrier wall. The test method involved placing the core samples in a concrete sulfate wet-dry cycle tester for sulfate etching. The water absorption, compressive strength, and permeability of the test blocks after 30, 60, 90, 120, and 150 cycles of dry corrosion were measured. The results are shown in Table 1.

[0061] Table 1

[0062]

[0063] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 20 mg / kg, Cr 6+ The reduction rate was 60%; the benzo[a]pyrene content was 5.4 mg / kg, and the benzo[a]pyrene degradation rate was 46%.

[0064] Example 2

[0065] The curing materials consist of: 80 parts by weight of ordinary Portland cement as the first component; 19 parts by weight of slag as the second component, comprising 30 parts by weight of blast furnace slag and 70 parts by weight of fly ash, all with a particle size D90 of 0.1 mm; and 1 part by weight of the third component, comprising magnesium zinc aluminum hydrotalcite and bismuth oxychloride in a 1:1 mass ratio, all with a particle size D90 of 0.1 mm. Water and the curing materials are mixed at a mass ratio of 0.8:1 to prepare the seepage-proof barrier grouting material.

[0066] The slurry prepared above was injected in situ to form a vertical seepage barrier wall. Core samples were taken to test the performance of the vertical seepage barrier wall. The test method involved placing the extracted core samples in a concrete sulfate wet-dry cycle tester for sulfate corrosion. The water absorption, compressive strength, and permeability of the test blocks after 30, 60, 90, 120, and 150 cycles of dry corrosion were measured. The results are shown in Table 2.

[0067] Table 2

[0068]

[0069] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 21 mg / kg, Cr 6+ The reduction rate was 58%; the benzo[a]pyrene content was 6 mg / kg, and the benzo[a]pyrene degradation rate was 40%.

[0070] Example 3

[0071] Solidification materials: Component 1: 60 parts by weight of ordinary Portland cement; Component 2: 30 parts by weight of slag, of which blast furnace slag accounts for 50 parts by weight and fly ash accounts for 50 parts by weight, with a particle size D90 of 0.1 mm; Component 3: 10 parts by weight, of which zinc aluminum hydrotalcite and barium titanate are in a mass ratio of 5:1, with a particle size D90 of 0.01 mm.

[0072] A seepage-proof and barrier grouting slurry is prepared by mixing water and curing material at a mass ratio of 0.8:1.

[0073] The slurry prepared above was used to create a vertical seepage barrier wall through in-situ injection. Core samples were taken to test the performance of the vertical seepage barrier wall. The test method involved placing the extracted core samples in a concrete sulfate wet-dry cycle tester for sulfate corrosion. The water absorption, compressive strength, and permeability of the test blocks were measured after 30, 60, 90, 120, and 150 cycles of dry corrosion. The results are shown in Table 3.

[0074] Table 3

[0075]

[0076] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 18 mg / kg, Cr 6+ The reduction rate was 64%; the benzo[a]pyrene content was 5.8 mg / kg, and the benzo[a]pyrene degradation rate was 42%.

[0077] Example 4

[0078] The curing materials consist of: 70 parts by weight of ordinary Portland cement (component 1); 25 parts by weight of slag (component 20 parts by weight of blast furnace slag and 80 parts by weight of fly ash, both with a particle size D90 of 0.1 mm); and 5 parts by weight of admixtures (component 3), containing rare earth hydrotalcite and molybdenum sulfide in a 5:1 ratio, both with a particle size D90 of 0.1 mm. Water and the curing materials are mixed at a mass ratio of 0.8:1 to prepare the seepage-proof and barrier grouting material.

[0079] The slurry prepared above was used to create a vertical seepage barrier wall through in-situ injection. Core samples were taken to test the performance of the vertical seepage barrier wall. The test method involved placing the extracted core samples in a concrete sulfate wet-dry cycle tester for sulfate corrosion. The water absorption, compressive strength, and permeability of the test blocks were measured after 30, 60, 90, 120, and 150 cycles of dry corrosion. The results are shown in Table 4.

[0080] Table 4

[0081]

[0082] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 19 mg / kg, Cr 6+ The reduction rate was 62%; the benzo[a]pyrene content was 5.5 mg / kg, and the benzo[a]pyrene degradation rate was 45%.

[0083] Example 5

[0084] Solidification materials: Component 1: 50 parts by weight of ordinary Portland cement; Component 2: 45 parts by weight of slag, of which blast furnace slag accounts for 30 parts by weight and fly ash accounts for 70 parts by weight, with a particle size D90 of 0.1 mm; Component 3: 5 parts by weight, of which magnesium zinc aluminum hydrotalcite and lead zirconate titanate are in a mass ratio of 1:1, with a particle size D90 of 0.1 mm.

[0085] A seepage-proof and barrier grouting slurry is prepared by mixing water and curing material at a mass ratio of 0.8:1.

[0086] The slurry prepared in Example 1 was used to create a vertical seepage barrier wall through in-situ injection. Core samples were taken to test the performance of the vertical seepage barrier wall. The test method involved placing the extracted core samples in a concrete sulfate wet-dry cycle tester for sulfate etching. The water absorption, compressive strength, and permeability of the test blocks were measured after 30, 60, 90, 120, and 150 cycles of dry corrosion. The results are shown in Table 5.

[0087] Table 5

[0088]

[0089] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 20 mg / kg, Cr 6+ The reduction rate was 60%; the benzo[a]pyrene content was 5.3 mg / kg, and the benzo[a]pyrene degradation rate was 47%.

[0090] Example 6

[0091] The method is the same as in Example 2, except that the second component of fly ash is not added. Performance indicators are shown in Table 6.

[0092] Table 6

[0093]

[0094] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 24 mg / kg, Cr 6+ The reduction rate was 52%; the benzo[a]pyrene content was 6.2 mg / kg, and the benzo[a]pyrene degradation rate was 38%.

[0095] Example 7

[0096] The method is the same as in Example 2, except that the second component, blast furnace slag, is not added. Performance indicators are shown in Table 7.

[0097] Table 7

[0098]

[0099] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 22g / kg, Cr 6+ The reduction rate was 56%; the benzo[a]pyrene content was 6.5 mg / kg, and the benzo[a]pyrene degradation rate was 35%.

[0100] Example 8

[0101] The method is the same as in Example 2, except that the first component is 90 parts by weight. Performance indicators are shown in Table 8.

[0102] Table 8

[0103]

[0104] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 26 mg / kg, Cr 6+ The reduction rate was 48%; the benzo[a]pyrene content was 6.4 mg / kg, and the benzo[a]pyrene degradation rate was 36%.

[0105] Example 9

[0106] The method is the same as in Example 2, except that the second component is 60 parts by weight. Performance indicators are shown in Table 9.

[0107] Table 9

[0108]

[0109] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content was 27.5 mg / kg, Cr 6+ The reduction rate was 45%; the benzo[a]pyrene content was 6.2 mg / kg, and the benzo[a]pyrene degradation rate was 38%.

[0110] Example 10

[0111] The method is the same as in Example 2, except that the mass ratio of hydrotalcite to piezoelectric catalyst is 0.5:1. Performance indicators are shown in Table 10.

[0112] Table 10

[0113]

[0114]

[0115] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+The content is 25 mg / kg, Cr 6+ The reduction rate was 50%; the benzo[a]pyrene content was 6.2 mg / kg, and the benzo[a]pyrene degradation rate was 38%.

[0116] Example 11

[0117] The method of Example 2 was followed, except that the piezoelectric catalyst bismuth oxychloride was replaced with quartz crystal. Performance parameters are shown in Table 11.

[0118] Table 11

[0119]

[0120] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 45 mg / kg, Cr 6+ The reduction rate was 10%; the benzo[a]pyrene content was 9.5 mg / kg, and the benzo[a]pyrene degradation rate was 5%.

[0121] Comparative Example 1

[0122] The method is the same as in Example 2, except that no second component is added. Performance indicators are shown in Table 12.

[0123] Table 12

[0124]

[0125] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 22.5 mg / kg, Cr 6+ The reduction rate was 55%; the benzene content was 6.4 mg / kg, and the benzene degradation rate was 36%.

[0126] Comparative Example 2

[0127] The method of Example 2 was followed, except that the third component, magnesium zinc aluminum hydrotalcite, was not added. Performance indicators are shown in Table 13.

[0128] Table 13

[0129]

[0130] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content was 27.5 mg / kg, Cr 6+ The reduction rate was 45%; the benzo[a]pyrene content was 6.2 mg / kg, and the benzo[a]pyrene degradation rate was 38%.

[0131] Comparative Example 3

[0132] The method of Example 2 was followed, except that the third component, the piezoelectric catalyst bismuth oxychloride, was not added. Performance parameters are shown in Table 14.

[0133] Table 14

[0134]

[0135] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 48 mg / kg, Cr 6+ The reduction rate was 4%; the benzo[a]pyrene content was 9.6 mg / kg, and the benzo[a]pyrene degradation rate was 8%.

[0136] Comparative Example 4

[0137] The method of Example 2 was followed, except that the third component was replaced with a water glass and naphthalene sulfonate formaldehyde condensate. Performance indicators are shown in Table 15.

[0138] Table 15

[0139]

[0140] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 48 mg / kg, Cr 6+ The reduction rate was 4%; the benzo[a]pyrene content was 9.4 mg / kg, and the benzo[a]pyrene degradation rate was 6%.

[0141] Comparative Example 5

[0142] The method is the same as in Example 2, except that no third component is added. Performance indicators are shown in Table 16.

[0143] Table 16

[0144]

[0145] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content was 47.5 mg / kg, Cr 6+ The reduction rate was 5%; the benzo[a]pyrene content was 9.4 mg / kg, and the benzo[a]pyrene degradation rate was 6%.

[0146] Comparative Example 6

[0147] The method is the same as in Example 2, except that magnesium zinc aluminum hydrotalcite is replaced with brucite. Performance indicators are shown in Table 17.

[0148] Table 17

[0149]

[0150] Simultaneously, the core sample was placed in a water tank contaminated with heavy metals and organic pollutants, and ultrasonic mechanical vibration was applied to detect changes in the concentration of pollutants in the tank. The initial Cr concentration in the water tank... 6+ The initial concentration of benzo[a]pyrene was 10 mg / kg, and the Cr concentration in the water tank after repair was 50 mg / kg. 6+ The content is 32.5 mg / kg, Cr 6+ The reduction rate was 35%; the benzo[a]pyrene content was 7 mg / kg, and the benzo[a]pyrene degradation rate was 30%.

[0151] As can be seen from the results in the table above, the embodiments of the present invention can significantly improve the crack resistance, seepage resistance and corrosion resistance of vertical seepage prevention barriers, provide dual functions of barrier and repair, and avoid adverse effects on the surrounding environment.

[0152] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A curing material that combines seepage prevention and pollution remediation functions, characterized in that, The cured material is composed of a first component, a second component, and a third component; The first component is cement; The second component is slag; the slag includes blast furnace slag and fly ash; The third component is hydrotalcite and piezoelectric catalyst, and the weight ratio of hydrotalcite to piezoelectric catalyst is 1-5:1; The weight ratio of the first component, the second component, and the third component is 5-80:2-50:1; The blast furnace slag accounts for 30-50% of the total weight of the second component. The fly ash accounts for 50-70% of the total weight of the second component. The piezoelectric catalyst includes at least one of lead zirconate titanate, bismuth oxychloride, barium titanate, zinc oxide, molybdenum sulfide, and molybdenum selenide.

2. The curing material according to claim 1, wherein, The cement is silicate cement; And / or, according to standard GB175-2007, the cement strength grade is at least one of 42.5, 52.5 and 62.

5.

3. The curing material according to claim 1 or 2, wherein, The particle size distribution D90 of the second component is 0.005-0.1 mm.

4. The curing material according to claim 3, wherein, The particle size distribution D90 of the second component is 0.01-0.05 mm.

5. The curing material according to claim 1 or 2, wherein, The particle size distribution D90 of the third component is 0.005-0.1 mm; And / or, the hydrotalcite includes at least one of magnesium aluminum hydrotalcite, rare earth hydrotalcite, magnesium zinc aluminum hydrotalcite, and zinc aluminum hydrotalcite.

6. The curing material according to claim 5, wherein, The particle size distribution D90 of the third component is 0.01-0.05 mm.

7. A method for constructing a barrier wall for a solid waste storage site, characterized in that, The method includes: mixing the curing material according to any one of claims 1-6 with water and then using the mixture to form a wall.

8. The method according to claim 7, wherein, The weight ratio of the solidified material to water is 0.6-1.2:

1.

9. The method according to claim 7, wherein, The weight ratio of the solidified material to water is 0.8-1:

1.

10. The application of the solidification material according to any one of claims 1-6 in the vertical seepage prevention barrier of a composite polluted solid waste dump.

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