Permeable reactive barrier filling material as well as preparation method and application thereof

Abstract

The invention provides a permeable reactive barrier filling material as well as a preparation method and application thereof. The permeable reactive barrier filling material provided by the invention comprises a first molecular sieve, a second molecular sieve, a metal oxide, a mesoporous material and a binder, the silica-alumina ratio of the first molecular sieve is greater than or equal to 200, and the silica-alumina ratio of the second molecular sieve is 5-80. The permeable reactive barrier filling material disclosed by the invention comprises two molecular sieves with different silica-alumina ratios and metal oxides, can effectively combine adsorption and oxidation principles, is applied to treatment of soil and underground water, has good treatment performance on low-concentration organic pollutants in water, and is excellent in regeneration performance.

Description

Technical Field

[0001] The invention belongs to the technical field of organic contaminated soil treatment and restoration, and in particular relates to a permeable reaction wall filling material and a preparation method and application thereof. Background Art

[0002] Due to the lack of environmental protection concepts or accidents in history, there are a lot of contaminated soil and groundwater in all countries. European and American countries have a relatively long period of industrialization and have started to control soil and groundwater pollution earlier. With people's pursuit of a better life, the comprehensive control of domestic soil-contaminated groundwater has also received attention. The types of contaminated sites can be mainly divided into heavy metal pollution, organic pollution, radioactive pollution and complex pollution. Among them, permeable reactive barrier (PRB) is an in-situ groundwater pollution remediation technology, which has good application prospects in the treatment of various types of contaminated sites. It has the characteristics of long life, in-situ remediation to save land, and little impact on the environment. Its core is the development of permeable reactive wall filling materials.

[0003] In terms of organic contaminated soil treatment and remediation technology, permeable reaction wall filling materials can be divided into adsorption type, chemical oxidation type and biodegradation type according to their use principles. Commonly used adsorption materials include activated carbon, zeolite molecular sieves, aluminosilicates, organic carbon, etc.; chemical reduction materials mainly use metal oxides that can be used for redox reactions as active centers, combined with oxidants to oxidize organic pollutants in water; biodegradation types mainly load microorganisms onto active carriers, such as activated carbon, activated clay, quartz sand, bentonite, natural zeolite, etc., to degrade organic pollutants in water through biochemical reactions.

[0004] CN113979508A discloses a filling material, preparation method and application of a permeable reaction wall. The filling material provided by the method is a solid pellet, mainly composed of zero-valent iron, activated carbon, tourmaline and a binder, and mainly forms an iron-carbon primary battery underground with zero-valent iron and a carbon source to eliminate petroleum hydrocarbon pollution in water. The material provided by the method cannot be regenerated in situ, and will gradually become ineffective after use, which is not conducive to long-term operation or reuse.

[0005] CN110467250A discloses a microfiber composite NaA molecular sieve membrane-nano zero-valent iron composite material and its preparation method and application in wastewater treatment. The microfiber composite NaA molecular sieve membrane is soaked in a ferrous solution for 20 to 40 minutes, and sodium borohydride solution is added to the surface of the microfiber composite NaA molecular sieve membrane after taking it out. After 1 to 3 hours of dripping, the microfiber composite NaA molecular sieve membrane-nano zero-valent iron composite material is obtained by suction filtration, washing, and vacuum drying. The microfiber composite NaA molecular sieve membrane-nano zero-valent iron composite material can further remove azo dyes and COD in the wastewater after treating heavy metals in the wastewater. The method has a low COD treatment capacity, with a maximum of only 66.3%, and the characteristic pollutants treated are single.

[0006] EP1697264B1 discloses a method for treating contaminated water using zeolite molecular sieves with different characteristics. The method mainly uses a composite method of two zeolite molecular sieves to remove low and high concentrations of underground pollutants. Specifically, ZSM-5 and Y zeolite molecular sieves are used. However, the permeable reaction wall material is mainly based on adsorption. When the adsorption is saturated, the material cannot be used anymore.

[0007] In summary, in the existing technologies, the types of adsorption materials are relatively single, it is difficult to treat complex components in the soil, and the adsorption capacity is limited; the traditional chemical oxidation materials have a small range of resistance to concentration fluctuations during use, and because the groundwater flow rate varies with the seasons, it may lead to insufficient treatment depth; the universality of biodegradable materials is poor. Due to the large differences in the environment of different sites, various components in the water will affect the survival of microorganisms, and it is necessary to cultivate microorganisms that adapt to the site, which takes a long time, and activated sludge will be produced during long-term use, which may block the permeable reaction wall. Therefore, it is necessary to develop a permeable reaction wall material with excellent treatment performance. Summary of the invention

[0008] In view of the problems existing in the prior art, the present invention provides a permeable reaction wall filling material and a preparation method thereof. The permeable reaction wall filling material of the present invention comprises two molecular sieves with different silicon-aluminum ratios and metal oxides, which can effectively combine the principles of adsorption and oxidation, and is applied in the treatment of soil and groundwater. It has good treatment performance for low-concentration organic pollutants in water and excellent regeneration performance.

[0009] In a first aspect, the present invention provides a permeable reaction wall packing material, which includes a first molecular sieve, a second molecular sieve, a metal oxide, a mesoporous material and a binder.

[0010] In some embodiments, the silicon-to-aluminum ratio of the first molecular sieve is greater than or equal to 200. In some embodiments, the silicon-to-aluminum ratio of the first molecular sieve is infinite, that is, the first molecular sieve is an all-silicon molecular sieve. In some embodiments, the silicon-to-aluminum ratio of the first molecular sieve is 200-1000.

[0011] In some embodiments, the silicon to aluminum ratio of the second molecular sieve is 5-90. In some embodiments, the silicon to aluminum ratio of the second molecular sieve is 7, 10, 13, 15, 17, 20, 23, 25, 27, 30, 33, 35, 37, 40, 43, 45, 47, 50, 53, 55, 57, 60, 63, 65, 67, 70, 73, 75, 77, 80, 83, 85, 87 or any value therebetween. In some embodiments, the silicon to aluminum ratio of the second molecular sieve is 15-50.

[0012] In some embodiments, the mass content of sodium in the first molecular sieve is 0.01%-0.5%, for example, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4% or 0.45%.

[0013] In some embodiments, the mass content of sodium element in the second molecular sieve is 0.01%-2%, for example, 0.05%, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8% or 1.9%.

[0014] In some embodiments, based on the mass of the permeable reaction wall filling material, the mass content of the first molecular sieve is 5%-20%, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% or 19%.

[0015] In some embodiments, based on the mass of the permeable reaction wall filling material, the mass content of the second molecular sieve is 10%-30%. In some embodiments, based on the mass of the permeable reaction wall filling material, the mass content of the second molecular sieve is 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 24.5%, 25%, 25.5%, 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, 31%, 32%, 33% or any value therebetween. In some embodiments, based on the mass of the permeable reaction wall filling material, the mass content of the second molecular sieve is 20%-34%.

[0016] In some embodiments, the first molecular sieve is selected from one or more of an MFI type molecular sieve and a BEA type molecular sieve.

[0017] In some embodiments, the second molecular sieve is selected from one or more of a BEA type molecular sieve, a FAU type molecular sieve, a MWW type molecular sieve, and a MFI type molecular sieve.

[0018] In some embodiments, the mass content of the metal oxide is 1%-10% based on the mass of the permeable reactive wall filling material. In some embodiments, the mass content of the metal oxide is 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 12%, 13%, 14% or any value therebetween based on the mass of the permeable reactive wall filling material. In some embodiments, the mass content of the metal oxide is 2%-15% based on the mass of the permeable reactive wall filling material.

[0019] In some embodiments, based on the mass of the permeable reactive wall filling material, the mass content of the mesoporous material is 5%-20%, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% or 19%.

[0020] In some embodiments, the mass content of the binder is 20%-80% based on the mass of the permeable reactive wall filling material. In some embodiments, the mass content of the binder is 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or any value therebetween based on the mass of the permeable reactive wall filling material.

[0021] In some embodiments, the metal oxide is selected from one or more of iron oxides.

[0022] In some embodiments, the XRD spectrum of the mesoporous material has a diffraction peak in the range of 1°-3°. In some embodiments, the mesoporous material is selected from one or more of M41S molecular sieve and SBA-15 molecular sieve.

[0023] In some embodiments, the binder has a pore size distribution of 5 nm to 20 nm. In some embodiments, the binder is selected from one or more of pseudo-boehmite, activated clay, diatomaceous earth and montmorillonite.

[0024] In some embodiments, the total specific surface area of ​​the permeable reactive wall filling material is 150 m 2 / g-500m 2 / g.

[0025] In some embodiments, the micropore specific surface area of ​​the permeable reactive wall filling material is 50%-90% of the total specific surface area.

[0026] In some embodiments, the total pore volume of the permeable reactive wall packing material is 0.1 mL / g to 0.6 mL / g.

[0027] In some embodiments, the mechanical strength of the permeable reactive wall filling material is 100 N / cm-200 N / cm.

[0028] In a second aspect, the present invention provides a method for preparing a permeable reactive wall filling material, comprising:

[0029] S1: forming a mixture including a first molecular sieve, a second molecular sieve, a metal oxide precursor, a mesoporous material, a binder and a pore-forming agent to obtain a formed solid;

[0030] S2: Drying and calcining the shaped solid to obtain the permeable reaction wall filling material.

[0031] In some embodiments, the silicon-to-aluminum ratio of the first molecular sieve is greater than or equal to 200. In some embodiments, the silicon-to-aluminum ratio of the first molecular sieve is infinite, that is, the first molecular sieve is an all-silicon molecular sieve. In some embodiments, the silicon-to-aluminum ratio of the first molecular sieve is 200-1000.

[0032] In some embodiments, the silicon to aluminum ratio of the second molecular sieve is 5-90. In some embodiments, the silicon to aluminum ratio of the second molecular sieve is 7, 10, 13, 15, 17, 20, 23, 25, 27, 30, 33, 35, 37, 40, 43, 45, 47, 50, 53, 55, 57, 60, 63, 65, 67, 70, 73, 75, 77, 80, 83, 85, 87 or any value therebetween. In some embodiments, the silicon to aluminum ratio of the second molecular sieve is 5-50.

[0033] In some embodiments, the mass content of sodium in the first molecular sieve is 0.01%-0.5%, for example, 0.1%, 0.15%, 0.2%, 0.25%, 0.3%, 0.35%, 0.4% or 0.45%.

[0034] In some embodiments, the mass content of sodium in the second molecular sieve is 0.01%-2%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8% or 1.9%.

[0035] In some embodiments, based on the mass of the shaped solid, the mass content of the first molecular sieve is 5%-20%, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% or 19%.

[0036] In some embodiments, based on the mass of the shaped solid, the mass content of the second molecular sieve is 10%-30%. In some embodiments, based on the mass of the shaped solid, the mass content of the second molecular sieve is 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, 24.5%, 25%, 25.5%, 26%, 26.5%, 27%, 27.5%, 28%, 28.5%, 29%, 29.5%, 30%, 31%, 32%, 33% or any value therebetween. In some embodiments, based on the mass of the shaped solid, the mass content of the second molecular sieve is 20%-34%.

[0037] In some embodiments, the first molecular sieve is selected from one or more of an MFI type molecular sieve and a BEA type molecular sieve.

[0038] In some embodiments, the second molecular sieve is selected from one or more of a BEA type molecular sieve, a FAU type molecular sieve, a MWW type molecular sieve, and a MFI type molecular sieve.

[0039] In some embodiments, the mass content of the metal oxide precursor is 1%-10% based on the mass of the shaped solid. In some embodiments, the mass content of the metal oxide is 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 5.5%, 6%, 6.5%, 7%, 7.5%, 8%, 8.5%, 9%, 9.5%, 10%, 10.5%, 11%, 12%, 13%, 14% or any value therebetween based on the mass of the shaped solid. In some embodiments, the mass content of the metal oxide is 2%-15% based on the mass of the shaped solid.

[0040] In some embodiments, the metal oxide precursor is selected from one or more of iron salts. In some embodiments, the metal oxide precursor is selected from one or more of ferric nitrate, ferric sulfate and ferrous sulfate.

[0041] In some embodiments, the mass content of the mesoporous material is 5%-20% based on the mass of the shaped solid, for example, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% or 19%.

[0042] In some embodiments, the XRD spectrum of the mesoporous material has a diffraction peak in the range of 1°-3°. In some embodiments, the mesoporous material is selected from one or more of M41S molecular sieve and SBA-15 molecular sieve.

[0043] In some embodiments, the mass content of the binder is 20%-80% based on the mass of the shaped solid. In some embodiments, the mass content of the binder is 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75% or any value therebetween based on the mass of the shaped solid.

[0044] In some embodiments, the binder has a pore size distribution of 5 nm to 20 nm. In some embodiments, the binder is selected from one or more of pseudo-boehmite, activated clay, diatomaceous earth and montmorillonite.

[0045] In some embodiments, the mass content of the pore former is 0.05%-2%, for example, 0.1%, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9%, 1.0%, 1.1%, 1.2%, 1.3%, 1.4%, 1.5%, 1.6%, 1.7%, 1.8% or 1.9%, based on the mass of the shaped solid.

[0046] In some embodiments, the pore former is selected from one or more of sesbania powder and cellulose.

[0047] In some embodiments, in S1, the molding process is selected from at least one of extrusion molding, ball molding, tablet molding or spray molding.

[0048] In some embodiments, in S2, the drying temperature is 50° C.-120° C., for example, 60° C., 70° C., 80° C., 90° C., 100° C. or 110° C. In some embodiments, in S2, the drying time is 2 h-24 h, for example, 4 h, 6 h, 8 h, 10 h, 12 h, 14 h, 16 h, 18 h, 20 h or 22 h.

[0049] In some embodiments, in S2, the calcination temperature is 500°C-650°C, for example, 530°C, 550°C, 570°C, 600°C or 630°C.

[0050] In a third aspect, the present invention provides use of the permeable reaction wall filling material described in the first aspect or the permeable reaction wall filling material prepared by the preparation method described in the second aspect in water treatment.

[0051] In some embodiments, the organic pollution in the soil groundwater (laboratory simulated contaminated groundwater) includes toluene, ethylbenzene, phenol, MTBE, and gasoline, and the total organic carbon concentration thereof is 30 mg / L to 300 mg / L.

[0052] In some embodiments, the water treatment is soil and groundwater treatment. In some embodiments, the organic pollutants in the soil and groundwater (actually contaminated groundwater on site) include volatile organic compounds (VOCs), semi-volatile organic compounds (SVOCs), total petroleum hydrocarbons TPH (C6-C9), and TPH (C6-C9). Volatile organic compounds include benzene, toluene, ethylbenzene, and xylene, and semi-volatile organic compounds include benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, and indeno(1,2,3-cd)pyrene.

[0053] Compared with the prior art, the present invention has the following excellent effects:

[0054] The first molecular sieve, i.e., high-silicon molecular sieve material, used in the permeable reaction wall filling material of the present invention is hydrophobic and can reduce the competitive adsorption of water, thereby improving the material's treatment depth for organic matter in water; the second type of molecular sieve can not only adsorb some organic pollutants, but also serve as a solid acid to provide acid centers for the permeable reaction wall material; the material has a multi-level pore distribution by compounding molecular sieves of different pore sizes, which can expand its application range and has strong adaptability; loaded with active metal oxides, combined with the acid center of the material, it can be regenerated in situ, and can be regenerated ex situ after failure after in situ regeneration; using a material with a certain mesoporous distribution as a binder, in addition to giving the material a certain mechanical strength, it can also provide a specific surface area for adsorption and retention of macromolecular substances. The permeable reaction wall filling material of the present invention is used in the treatment of soil and groundwater, and has good treatment performance for low-concentration organic pollutants in water, and excellent regeneration performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0055] Figure 1 Permeable reactive wall fill materials according to some embodiments of the present invention are shown. DETAILED DESCRIPTION

[0056] In order to make the purpose, technical scheme and advantages of the present invention clearer, the present invention is further described in detail below in conjunction with the embodiments and drawings. The specific embodiments described herein are only used to explain the present invention and are not intended to constitute any limitation to the present invention. In addition, in the following description, the description of known structures and technologies is omitted to avoid unnecessary confusion of the concepts of the present disclosure. Such structures and technologies are also described in many publications.

[0057] The endpoints and any values ​​of the ranges disclosed in this article 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 each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0058] The present invention will be described in detail below through examples.

[0059] In the present invention, the specific surface area and pore volume of the permeable reaction wall filling material are both well-known in the art and can be tested using methods and instruments known in the art. Specifically, the ASAP2020M physical and chemical adsorption instrument of the American Micromeritics Instrument Company was used. The sample was evacuated before measurement and treated at a constant temperature of 300°C for 2 hours to remove impurities attached to the surface of the sample. Then, high-purity N2 was adsorbed at low temperature of liquid nitrogen to obtain the adsorption / desorption curve of the permeable reaction wall filling material. The specific surface area was calculated by the BET method, and the pore volume was calculated according to the BJH method.

[0060] In the present invention, the chemical composition of the sample, ie, the silicon-aluminum ratio, is measured by an X-ray fluorescence spectrometer, the instrument model being Bruker S4 Pioneer.

[0061] In the present invention, the mechanical strength of the permeable reaction wall filling material has a well-known meaning in the art and can be tested using methods and instruments known in the art. Specifically, the catalyst strength is measured using a DLⅢ intelligent particle strength tester produced by Dalian Chemical Research and Design Institute, and the measurement is performed 22 times, and the maximum and minimum values ​​are removed to obtain the average value.

[0062] In the present invention, the total organic carbon (TOC) of the sample was measured using Shimadzu TOC-L CPH / CPN Total organic carbon analyzer.

[0063] In the present invention, VOCs are analyzed by gas chromatography-mass spectrometry, and SVOCs are analyzed by high performance liquid chromatography and gas chromatography.

[0064] Example 1

[0065] Preparation of permeable reactive wall filling materials:

[0066] The first molecular sieve high-silicon β molecular sieve powder (all silicon), the second molecular sieve ammonium-exchanged β molecular sieve powder (silicon-aluminum ratio 25), M41S mesoporous material powder, ferrous sulfate (measured in terms of ferric oxide), attapulgite, and pore-forming agent sesbania powder are measured in a mass ratio of 10:20:10:5:30:0.1, mixed evenly, and then extruded into strips (3 mm strips), dried, and calcined at 580°C.

[0067] Preparation and evaluation of permeable reactive wall filling materials:

[0068] The evaluation was conducted by fixed bed column experiment. The permeable reaction material was loaded into the reaction column. The aqueous solution pollutants and 8% mass concentration hydrogen peroxide were fed in a mass ratio of 20:1 in a bottom-in-top-out manner. The total mass space velocity was 1.5 h -1 , the reaction is carried out under normal pressure and temperature conditions.

[0069] The soil and groundwater pollutants treated are: toluene, ethylbenzene, phenol, MTBE, gasoline, and benzo[a]anthracene are mixed with water in a mass ratio of 2:2:2:2:10:1 to form an aqueous solution with a TOC concentration of 150 mg / L.

[0070] The specific characterization and evaluation results are shown in Table 1.

[0071] Example 2

[0072] The difference from Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in terms of ferric oxide), attapulgite and pore-forming agent is 10:20:10:5:50:0.1. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0073] In addition, the permeable reaction wall filling material prepared in this embodiment was used to evaluate the soil groundwater of a petrochemical site, and its initial TPH was 130 mg / L, and the TPH after treatment was 12 mg / L.

[0074] The permeable reactive wall filling material prepared in this embodiment was used to evaluate the soil groundwater of another petrochemical site. The initial TPH was 10 mg / L, the groundwater flow rate was 50 m / year, and the PRB wall thickness was 0.6 m. After the 180th day, the TPH after treatment was 0.5 mg / L, and benzene, toluene, ethylbenzene, xylene, and semi-volatile organic compounds (including benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene, etc.) were not detected after treatment (the detection limit was 10 -6 mg / L).

[0075] Example 3

[0076] The difference from Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in terms of ferric oxide), attapulgite and pore-forming agent is 10:20:10:5:100:0.1. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0077] Embodiment 4 to Embodiment 6

[0078] The difference from Example 1 is that the silicon-to-aluminum ratio of the second molecular sieve is 10, 50, and 75, respectively. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0079] Example 7

[0080] The difference from Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in mass as ferric oxide), attapulgite and pore-forming agent is 10:22:10:3:30:0.1. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0081] Example 8

[0082] The difference from Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in terms of ferric oxide), attapulgite and pore-forming agent is 10:24:10:1:30:0.1. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0083] Example 9

[0084] The difference from Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in terms of ferric oxide), attapulgite and pore-forming agent is 10:18:10:7:30:0.1. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0085] Example 10

[0086] The difference from Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in mass as ferric oxide), attapulgite and pore-forming agent is 10:15:10:10:30:0.1. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0087] Comparative Example 1

[0088] The difference between Comparative Example 1 and Example 1 is that the first molecular sieve high-silicon β molecular sieve is not added. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0089] Comparative Example 2

[0090] The difference between Comparative Example 2 and Example 1 is that the second molecular sieve ammonium-exchanged β molecular sieve is not added. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0091] Comparative Example 3

[0092] The difference between Comparative Example 3 and Example 1 is that the M41S mesoporous material is not added. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0093] Comparative Example 4-Comparative Example 5

[0094] The difference between Comparative Example 4-5 and Example 1 is that the silicon-aluminum ratio of the second molecular sieve is 100 and 200 respectively. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0095] Comparative Example 6

[0096] The difference between Comparative Example 6 and Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in mass as ferric oxide), attapulgite and pore-forming agent is 10:25:10:0:30:0.1, that is, ferrous sulfate is not added. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0097] Comparative Example 7

[0098] The difference between Comparative Example 7 and Example 1 is that the mass ratio of the first molecular sieve high silicon β molecular sieve powder, the second molecular sieve ammonium exchanged β molecular sieve powder, M41S mesoporous material powder, ferrous sulfate (measured in mass as ferric oxide), attapulgite and pore-forming agent is 10:0:10:25:30:0.1, that is, the second molecular sieve is not added. The characterization and evaluation results of the permeable reaction wall filling material are shown in Table 1.

[0099] Table 1

[0100]

[0101] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A permeable reaction wall filling material, comprising a first molecular sieve, a second molecular sieve, a metal oxide, a mesoporous material and a binder; Preferably, the silicon-to-aluminum ratio of the first molecular sieve is greater than or equal to 200, and the silicon-to-aluminum ratio of the second molecular sieve is 5-90.

2. The permeable reactive wall filling material according to claim 1, characterized in that: The silicon-aluminum ratio of the first molecular sieve is 200-1000; preferably, the mass content of sodium element in the first molecular sieve is 0.01%-0.5%; and / or The silicon-to-aluminum ratio of the second molecular sieve is 15-50. Preferably, the mass content of the sodium element in the second molecular sieve is 0.01%-2%.

3. The permeable reactive wall filling material according to claim 1 or 2, characterized in that: Based on the mass of the permeable reaction wall filling material, the mass content of the first molecular sieve is 5%-20%; and / or Based on the mass of the permeable reaction wall filling material, the mass content of the second molecular sieve is 10%-30%.

4. The permeable reactive wall filling material according to any one of claims 1 to 3, characterized in that: The first molecular sieve is selected from one or more of MFI type molecular sieve and BEA type molecular sieve; and / or The second molecular sieve is selected from one or more of BEA type molecular sieve, FAU type molecular sieve, MWW type molecular sieve and MFI type molecular sieve.

5. The permeable reactive wall filling material according to any one of claims 1 to 4, characterized in that: Based on the mass of the permeable reaction wall filling material, the mass content of the metal oxide is 1%-10%, and / or The mass content of the mesoporous material is 5%-20%, and / or The mass content of the binder is 20%-80%.

6. The permeable reactive wall filling material according to any one of claims 1 to 5, characterized in that: The metal oxide is selected from one or more of iron oxides; and / or The XRD spectrum of the mesoporous material has a diffraction peak in the range of 1°-3°. Preferably, the mesoporous material is selected from one or more of M41S molecular sieve and SBA-15 molecular sieve; and / or The binder has a pore size distribution of 5nm-20nm. Preferably, the binder is selected from one or more of pseudo-boehmite, attapulgite, diatomaceous earth, montmorillonite and kaolin.

7. The permeable reactive wall filling material according to any one of claims 1 to 6, characterized in that: The total specific surface area of ​​the permeable reaction wall filling material is 150m 2 / g-500m 2 / g, Preferably, the micropore specific surface area of ​​the permeable reactive wall filling material is 50%-90% of the total specific surface area; and / or The total pore volume of the permeable reaction wall filling material is 0.1 mL / g to 0.6 mL / g; and / or The mechanical strength of the permeable reaction wall filling material is 100N / cm-200N / cm.

8. A method for preparing the permeable reactive wall filling material according to any one of claims 1 to 7, comprising: S1: forming a mixture including a first molecular sieve, a second molecular sieve, a metal oxide precursor, a binder, a pore former and a mesoporous material to obtain a formed solid; S2: drying and calcining the formed solid to obtain the permeable reaction wall filling material; Preferably, based on the mass of the shaped solid, the mass content of the first molecular sieve is 5%-20%, the mass content of the second molecular sieve is 10%-30%, the mass content of the metal oxide precursor is 1%-10%, the mass content of the mesoporous material is 5%-20%, the mass content of the binder is 20%-80%, and the mass content of the pore-forming agent is 0.05%-2%.

9. The preparation method according to claim 8, characterized in that: The pore-forming agent is selected from one or more of sesbania powder and cellulose; and / or The metal oxide precursor is selected from one or more iron salts, preferably one or more iron nitrate, iron sulfate and ferrous sulfate; and / or In S2, the drying temperature is 50°C-120°C, and / or the calcining temperature is 500°C-650°C.

10. Use of the permeable reactive wall filling material according to any one of claims 1 to 7 or the permeable reactive wall filling material prepared by the preparation method according to claim 8 or 9 in water treatment, preferably soil and groundwater treatment.

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