A waste tire geotechnical structure and a benzene permeation prevention treatment method thereof

Abstract

The application discloses a kind of waste tire geotechnical structure and its benzene permeation prevention processing method, processing method includes the following steps: waste mask disinfection treatment;ZnCl2 is dissolved in HCl, preprocessed activated carbon is added, after oscillation stirring, make ZnCl2 solution enter into activated carbon, dry to constant weight, with nitrogen at 850~900 ℃, activated carbon is activated, and ZnCl2 modified activated carbon is obtained;Multiple waste masks are tied together, and ZnCl2 modified activated carbon is wrapped between adjacent waste masks;Fixed on geogrid, the outer layer non-woven fabric of waste mask is towards waste tire, the inner layer non-woven fabric is towards geogrid, and ZnCl2 modified activated carbon is rolled on the tread pattern groove of waste tire;The bottom end of geogrid is fixed with lock catch.The application effectively solves the potential harm generated when waste tire is applied to geotechnical application, expands the application field of waste tire, and reduces the pollution generated when waste tire is used in soil.

Description

Technical Field

[0001] This invention belongs to the field of environmental protection treatment, specifically a waste tire geostructure and its benzene-proofing treatment method. Background Technology

[0002] In order to apply waste tire retaining walls to geotechnical applications (such as tire strip reinforced soil, tire retaining walls supporting soil, etc.), existing technologies mainly focus on optimizing and innovating the mechanical properties of waste tires and the overall performance of tire retaining walls. However, whether waste tires cause harm to the soil determines whether waste tires can be used in actual geotechnical applications.

[0003] Experimental data shows that when waste tires are used above the groundwater level, they do not affect the soil. However, when used below the groundwater level, prolonged immersion causes leachate from the tires and the water body to leach into the soil, releasing a certain amount of benzene. When this benzene leaks or is discharged into the soil, it can easily seep in and migrate, leading to soil pollution. Benzene is toxic to soil microorganisms, disrupting the balance of the soil ecosystem, reducing soil fertility and crop yields. Therefore, measures need to be taken to address the pathological problems associated with waste tire retaining walls, alleviate public concerns about their potential impact, and expand the application of tire retaining walls.

[0004] Benzene is difficult to degrade and easily accumulates in organisms. Long-term exposure to benzene through the skin and respiratory tract can irritate the skin, affect blood cell function, and even cause leukemia. Existing waste tire retaining walls will generate benzene pollution problems during long-term use. Summary of the Invention

[0005] Purpose of the invention: In order to overcome the shortcomings of the existing technology, the purpose of this invention is to provide a highly efficient benzene adsorption method for benzene-proofing treatment applied to waste tire geostructures. Another purpose of this invention is to provide an environmentally friendly and energy-saving waste tire geostructure.

[0006] Technical solution: The present invention provides a method for preventing benzene penetration into waste tire geostructures, comprising the following steps:

[0007] Step 1: Discarded masks are disinfected, causing the surface to expand and form a superhydrophobic layer;

[0008] Step 2: Dissolve ZnCl2 in HCl, add pretreated activated carbon, shake and stir to allow the ZnCl2 solution to fully enter the pores of the activated carbon, dry to constant weight, and activate the activated carbon with nitrogen at 850-900℃ to obtain ZnCl2 modified activated carbon, which can greatly enhance the benzene absorption and energy dissipation of activated carbon.

[0009] Step 3: Tie multiple discarded masks together, and wrap ZnCl2 modified activated carbon between adjacent discarded masks;

[0010] Step four: Fix the material obtained in step three onto the geogrid, with the outer non-woven fabric of the discarded mask facing the waste tire and the inner non-woven fabric facing the geogrid. Press ZnCl2 modified activated carbon into the tread grooves of the waste tire to further reduce the benzene element leaching from the waste tire.

[0011] Further, in step one, the disinfection treatment of discarded masks involves soaking them in a NaOH and ethanol solution for 1–3 hours. The NaOH content in the NaOH and ethanol solution is 10–12 wt%, removing surface oil and other contaminants. Surface expansion is achieved by treating the mask surface with an alkane solvent, followed by low-temperature evaporation to remove the alkane solvent. The alkane solvent is either diethyl ether or petroleum ether. Discarded masks may contain pathogens, and improper handling could easily lead to virus transmission; therefore, simple disinfection treatment is necessary before further use.

[0012] Further, in step two, the activated carbon is walnut shell powder or sugarcane bagasse. The pretreatment of the activated carbon involves cutting it into small pieces, washing it repeatedly with distilled water to remove impurities, shaking it on a shaker at 110–120 rpm and 20–30°C for 3–4 hours, washing the activated carbon with deionized water until the pH value remains constant, and drying it to constant weight. The mass-to-volume ratio of ZnCl2, HCl, and activated carbon is 50 g: 50 mL: 8–10 g.

[0013] The adsorption capacity of face masks mainly comes from the internal meltblown cotton. Experiments and data analysis revealed that discarded face masks still adsorb benzene compounds (benzene, toluene, and xylene) relatively quickly, reaching saturation in 10 seconds. The saturation adsorption capacity increases with decreasing diameter and increasing porosity of the internal meltblown cotton fibers. Therefore, treating the mask surface with alkane solvents (such as diethyl ether and petroleum ether) causes the surface of the discarded mask to expand, forming a superhydrophobic layer. This significantly improves the adsorption effect and increases the surface roughness of the treated mask. Furthermore, trace amounts of benzene from the alkane solvent are absorbed by the modified internal meltblown cotton. However, the benzene adsorption capacity of the treated internal meltblown cotton is limited. To ensure subsequent benzene absorption, this invention incorporates ZnCl2-modified activated carbon into the treated discarded face mask.

[0014] Furthermore, in step three, there are two ways to combine the discarded masks. First, multiple discarded masks are glued or sewn together at the vertical straps. Second, multiple discarded masks have their straps removed to create a gap, the straps are threaded through the gap, and then tied together.

[0015] Furthermore, the discarded masks were disposable medical masks with a corrugated outer non-woven fabric layer.

[0016] The soil is the part that needs to be protected, and the tire is the source of external leaching pollution, so the outer non-woven fabric faces the tire surface and the inner non-woven fabric faces the soil surface.

[0017] The present invention discloses a waste tire geostructure based on waste masks and activated carbon, comprising the aforementioned waste tire, geogrid, and waste mask layer; ZnCl2 modified activated carbon is rolled into the tread grooves of the waste tire; the waste mask layer consists of multiple waste masks tied together and containing ZnCl2 modified activated carbon inside, with the outer non-woven fabric of the waste mask facing the waste tire and the inner non-woven fabric facing the geogrid.

[0018] Working principle: The mask layer filters impurities, allowing the activated carbon to fully adsorb benzene without being affected by other impurities. In addition, after the mask is treated, the internal meltblown cotton forms a superhydrophobic layer, which enhances the mask's ability to adsorb benzene.

[0019] Beneficial effects: Compared with the prior art, the present invention has the following significant features:

[0020] 1. By using discarded masks and activated carbon, the potential hazards caused by the use of waste tires in geotechnical applications are effectively solved, expanding the application field of waste tires and reducing the pollution generated when waste tires are used in soil.

[0021] 2. Compared to the direct burial of discarded masks, this method provides a way to recycle discarded masks, promotes the sustainable use of discarded masks and realizes valuable and novel functions, reduces negative environmental impact, reduces energy consumption, and lowers carbon emissions.

[0022] 3. The treated waste masks do not carry germs, and according to the treatment method of the present invention, the treated waste masks have a significant effect on adsorbing benzene produced by waste tires. As the first line of defense, they have excellent anti-pollution performance, and the mask connection method is also convenient for construction in geotechnical applications.

[0023] 4. Biomass activated carbon is made from readily available, inexpensive, environmentally friendly, and renewable raw materials. Modified biomass activated carbon enhances its ability to adsorb benzene. It has a large specific surface area and pore volume, serving as a second line of defense with high adsorption efficiency. Combined with the first line of defense of waste masks, it can further improve the environmental safety of waste tires when used in geotechnical applications.

[0024] 5. Treating the surface of masks with solvents such as ether and petroleum ether will cause the meltblown cotton inside the discarded masks to expand and form a superhydrophobic layer, which will enhance the mask's ability to adsorb benzene. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of the structure of the discarded mask 1 of the present invention;

[0026] Figure 2 This is a schematic diagram of the structure of the discarded mask 1 with the mask strap 103 removed;

[0027] Figure 3 This is one of the combination methods of the discarded mask 1 of the present invention;

[0028] Figure 4 This is the second combination method of the discarded mask 1 of the present invention;

[0029] Figure 5 This is a schematic diagram showing the connection between the activated carbon 2 and the discarded mask 1 of the present invention;

[0030] Figure 6 This is a schematic diagram of the surface treatment of the tread grooves 4 of the waste tire 3 of the present invention;

[0031] Figure 7 This is a schematic diagram showing the connection between the discarded mask 1 and the geogrid 5 of the present invention;

[0032] Figure 8 This is a schematic diagram showing the connection between the waste tire 3 and the geogrid 5 of the present invention.

[0033] Figure 9 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0034] Figure 10 This is a schematic diagram of the structure of Embodiment 3 of the present invention. Detailed Implementation

[0035] All reagents listed below are of analytical grade.

[0036] Example 1

[0037] like Figures 1-8 A method for preventing benzene penetration in waste tire geotechnical structures includes pretreatment of waste masks 1, a combination of ZnCl2 modified activated carbon 2 and waste masks 1, a waste mask 1-ZnCl2 modified activated carbon 2 structure, surface treatment of waste tires 3, and connection of the tire retaining wall with the waste mask 1-ZnCl2 modified activated carbon 2 structure. The specific steps are as follows:

[0038] Step 1, Pre-treatment of discarded masks 1, i.e., disinfection: Discarded masks 1 may contain germs, which can easily spread viruses if not handled properly. Therefore, they need to be disinfected before further use. First, the collected discarded masks 1 are soaked in a NaOH and ethanol solution for 2 hours to remove surface oil and other contaminants, resulting in pre-treated discarded masks 1. The NaOH in the NaOH and ethanol solution has a NaOH mass percentage of 10-12 wt%, preferably a 10 wt% sodium hydroxide ethanol solution.

[0039] The adsorption of benzene is enhanced by treating the internal meltblown cotton 105 of the discarded mask 1: The adsorption of benzene in the discarded mask 1 mainly comes from the internal meltblown cotton 105. Experimental tests and data analysis revealed that the discarded mask 1 still has a relatively fast adsorption rate for benzene compounds (benzene, toluene, and xylene), reaching saturation in 10 seconds. The saturated adsorption capacity increases with decreasing fiber diameter and increasing porosity of the internal meltblown cotton 105. Therefore, alkane solvents such as diethyl ether and petroleum ether are used to treat the surface of the discarded mask 1. The alkane solvent causes the surface of the discarded mask 1 to expand, forming a superhydrophobic layer, which is then removed by low-temperature evaporation. The adsorption effect of the treated discarded mask 1 is significantly improved, and the surface roughness is significantly increased. Trace amounts of benzene from the alkane solvent are also absorbed by the modified internal meltblown cotton. However, the benzene adsorption capacity of the treated internal meltblown cotton 105 is limited. To ensure subsequent benzene absorption, ZnCl2-modified activated carbon 2 is added to the treated discarded mask 1 in this invention. Step 2, ZnCl2 modified activated carbon 2: Activated carbon 2 types: walnut shells and sugarcane bagasse with high lignocellulose content for benzene removal. Modification method is as follows: 1. Cut biomass activated carbon 2 into small pieces, then wash the solid sample multiple times with distilled water to remove impurities. 2. Improve benzene adsorption effect: ZnCl2 modification can greatly enhance the benzene adsorption capacity of activated carbon 2. Therefore, this study uses ZnCl2 as an activator to modify activated carbon 2. Then, the washed activated carbon 2 and HCl (1mol / L) are placed in an Erlenmeyer flask and shaken on a shaker at 120 rpm and 20℃ for 4 hours to remove organic matter. After shaking, the activated carbon 2 is washed with deionized water until the pH value remains constant, and then dried in an oven at 60℃ for 24 hours to constant weight. 50g ZnCl2 is dissolved in 50mL HCl (1mol / L). 10g of pretreated activated carbon 2 is added to this solution, and the mixture is placed in a shaker and shaken at 120 rpm for 12 hours at 25℃. After shaking and stirring, the ZnCl2 solution was fully incorporated into the pores of activated carbon 2. Activated carbon 2 was then dried in a 60℃ oven until constant weight. Finally, activated carbon 2 was activated with nitrogen at 850℃ for 2 hours (heating rate 4℃ / min) to obtain ZnCl2-modified high-efficiency benzene-removing activated carbon 2.

[0040] Step 3, Assembly methods for discarded masks 1: Assembly method 1: Multiple discarded masks 1 are glued and sewn together at the vertical elastic band 101. Assembly method 2: First, remove the mask straps 102 of the discarded masks 1 (the mask straps are mostly fuzzy elastic bands). After removing the mask straps, four notches 103 will appear at the four o'clock position of the discarded mask 1. The mask straps 102 are passed through the notches 103 of the discarded mask 1 to tie multiple discarded masks 1 together.

[0041] Structure of Discarded Mask 1 - ZnCl2 Modified Activated Carbon 2: Most disposable discarded masks 1 are disposable medical masks (YY 0469-2011), so this invention uses this type of discarded mask 1. The outer non-woven fabric 104 of this mask is corrugated. The corrugated groove 107 is opened, and activated carbon 2 particles are poured into the groove 107, so that the discarded mask 1 wraps the modified activated carbon 2, and the two work together to adsorb benzene.

[0042] Step 4, surface treatment of waste tire 3: Conventional waste tires 3 have tread grooves 4 on their surface. After the waste tire 3 is rolled with the modified activated carbon 2 mentioned above, the activated carbon 2 is stuck in the tread grooves 4, which further reduces the benzene element leaching out of the waste tire 3.

[0043] Step 5, Connection method between the waste mask 1-ZnCl2 modified activated carbon 2 structure tire retaining wall and the waste mask 1-ZnCl2 modified activated carbon 2 structure: The waste mask 1-ZnCl2 modified activated carbon 2 structure in claim 5 is adhered or tied to the geogrid 5. The soil is the part that needs to be protected, and the tire is the external seepage pollution, so the outer non-woven fabric 104 faces the tire surface and the inner non-woven fabric 106 faces the soil surface.

[0044] Comparative Example 1

[0045] The remaining steps of this comparative example are the same as those in Example 1, except that the tread grooves 4 are all replaced with individual activated carbon with a specific surface area of ​​752 m². 2 ·g -1 Do not modify or use discarded masks.

[0046] Comparative Example 2

[0047] The remaining steps of this comparative example are the same as those of Example 1, except that: the discarded mask 1 is omitted, and the modified activated carbon has a specific surface area of ​​1185 m². 2 ·g -1 .

[0048] The benzene adsorption capacity of the structures obtained in Example 1, Comparative Example 1, and Comparative Example 2 was tested. The initial mass concentration of benzene was 17.2 mg / m³. 3 The benzene adsorption capacity of Comparative Example 1 was 98.65 mg / g, that of Comparative Example 2 was 172.43 mg / g, and that of Example 1 was 216.58 mg / g. This indicates that the waste mask 1 filters impurities, allowing the activated carbon to more fully adsorb benzene without being affected by other impurities in its internal structure. Furthermore, after treatment, the meltblown cotton 105 inside the mask forms a superhydrophobic layer, enhancing the mask's ability to adsorb benzene.

[0049] Example 2

[0050] like Figure 9 The reinforcing material of the recycled tire has undergone the same benzene-proofing treatment as in Example 1. ZnCl2-modified activated carbon 2 is present in the tread grooves 4 at the connection between the waste tire 3 and the geogrid 5. Multiple discarded masks 1 are tied together between the geogrid 5 and the recycled tire 3, with ZnCl2-modified activated carbon 2 wrapped between adjacent discarded masks 1. The waste tire 3 is completely buried in the soil.

[0051] Example 3

[0052] like Figure 10 The tire retaining wall has undergone the same benzene-proofing treatment as in Example 1. The tread grooves 4 of the waste tires 3 facing away from the soil of the tire retaining wall are rolled with ZnCl2 modified activated carbon 2. There are multiple waste masks 1 tied together between the waste tire panel facing the soil of the tire retaining wall below the groundwater level and the geogrid 5. ZnCl2 modified activated carbon 2 is wrapped between adjacent waste masks 1.

Claims

1. A method for preventing benzene penetration into geostructures made from waste tires, characterized in that, Includes the following steps: Step 1: Discarded masks are disinfected, causing the surface to expand and form a superhydrophobic layer; Step 2: Dissolve ZnCl2 in HCl, add pretreated activated carbon, shake and stir to allow the ZnCl2 solution to fully enter the pores of the activated carbon, dry to constant weight, and activate the activated carbon with nitrogen at 850~900℃ to obtain ZnCl2 modified activated carbon. Step 3: Tie multiple discarded masks together, and wrap ZnCl2 modified activated carbon between adjacent discarded masks; Step four: Fix the material obtained in step three onto the geogrid, with the outer non-woven fabric of the discarded mask facing the waste tire and the inner non-woven fabric facing the geogrid. ZnCl2 modified activated carbon is rolled into the tread grooves of the waste tire.

2. The method for preventing benzene penetration in waste tire geostructures according to claim 1, characterized in that: In step one, the disinfection treatment of the discarded masks involves soaking the discarded masks in a NaOH and ethanol solution for 1 to 3 hours, wherein the mass percentage of NaOH in the NaOH and ethanol solution is 10 to 12 wt%.

3. The method for preventing benzene penetration in waste tire geostructures according to claim 1, characterized in that: The surface expansion is achieved by treating the mask surface with an alkane solvent, followed by low-temperature evaporation to remove the alkane solvent.

4. The method for preventing benzene penetration in waste tire geostructures according to claim 1, characterized in that: In step two, the activated carbon is walnut shells or sugarcane bagasse.

5. A method for preventing benzene penetration into waste tire geostructures according to claim 1, characterized in that: In step two, the pretreatment of activated carbon involves cutting the activated carbon into small pieces, washing it multiple times with distilled water to remove impurities, shaking it on a shaker at 110-120 rpm and 20-30°C for 3-4 hours, washing the activated carbon with deionized water until the pH value remains unchanged, and drying it to a constant weight.

6. A method for preventing benzene penetration into waste tire geostructures according to claim 1, characterized in that: In step two, the mass-to-volume ratio of ZnCl2, HCl, and activated carbon is 50 g: 50 mL: 8~10 g.

7. The method for preventing benzene penetration in waste tire geostructures according to claim 1, characterized in that: In step three, multiple discarded masks are glued or sewn together at the vertical strip.

8. The method for preventing benzene penetration in waste tire geostructures according to claim 1, characterized in that: In step three, the mask straps of multiple discarded masks are first removed to create a gap, and then the mask straps are passed through the gap and tied together.

9. A method for preventing benzene penetration in waste tire geostructures according to claim 1, characterized in that: The discarded masks were disposable medical masks with a corrugated outer non-woven fabric layer.

10. A geostructure based on waste masks and activated carbon improved from waste tires, characterized in that: The method for preventing benzene penetration of waste tire geostructures according to any one of claims 1 to 9 is adopted. The waste tire geostructure includes waste tires, geogrids and waste mask layers; ZnCl2 modified activated carbon is rolled into the tread grooves of the waste tires. The discarded mask layer consists of multiple discarded masks tied together and containing ZnCl2 modified activated carbon inside. The outer non-woven fabric of the discarded mask faces the waste tire, and the inner non-woven fabric faces the geogrid.

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