Efficient heavy metal removal agent as well as preparation method and application thereof

Abstract

The invention provides an efficient heavy metal removal agent and a preparation method and application thereof, and the preparation method comprises the following steps: (1) mixing hot water and a synthetic agent to obtain a synthetic agent solution; (2) adding nano orange-hole soil, pyridine, a promoter and p-toluene sulfonic acid into the synthetic agent solution, stirring, adding a sodium hydroxide solution, and continuously stirring to obtain a premix; (3) mixing the premix with a sodium hydroxide solution for alkali salt absorption to obtain a first intermediate material; (4) dropwise adding a sodium thiocompound into the first intermediate material for primary reaction to obtain a second intermediate material; and (5) dropwise adding a cross-linking agent and a stabilizer into the second intermediate material to carry out secondary reaction, and carrying out solid-liquid separation to obtain the efficient heavy metal removal agent. The efficient heavy metal removal agent provided by the invention is pyridylthio amino hydroxyl sodium modified nanometer orange-hole soil with a porous structure and a long-chain material, is good in stability and high in selective adsorption capacity on heavy metal elements, meets the green and environment-friendly requirements, and is beneficial to large-scale popularization and application.

Description

Technical Field

[0001] The invention belongs to the technical field of heavy metal removal, and relates to a heavy metal removal agent, in particular to a high-efficiency heavy metal removal agent and a preparation method and application thereof. Background Art

[0002] Heavy metal pollution in water and soil is a global environmental problem, which mainly comes from industrial emissions, agricultural use of pesticides and fertilizers containing heavy metals, mining production activities and urban wastewater. These heavy metals include but are not limited to lead, mercury, cadmium, chromium and arsenic. These heavy metal elements are not easily degraded and can accumulate in the environment for a long time, accumulate through the food chain and eventually pose a serious threat to human health.

[0003] Traditional heavy metal removal technologies, such as chemical precipitation, ion exchange, membrane separation, etc., all have problems such as low treatment efficiency, high cost, complicated operation process or secondary pollution. For example, chemical precipitation may produce a large amount of sludge that is difficult to treat; ion exchange requires regular replacement of resin; membrane separation may lead to reduced efficiency due to membrane pollution, and there is still much room for improvement.

[0004] Nanomaterials have shown great application potential in the field of heavy metal removal due to their unique physical and chemical properties (such as high specific surface area, high reactivity and designability). Nanomaterials can provide more active sites, thereby improving the adsorption capacity and selectivity for heavy metal elements.

[0005] However, the existing technology of using nanomaterials to remove heavy metal elements generally has the problem of poor stability. Tiny nanomaterials are very easy to aggregate or precipitate in a liquid environment, thus affecting their performance. In addition, the environmental friendliness of nanomaterials during large-scale use is one of the focuses of technical personnel in this field. Summary of the invention

[0006] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a high-efficiency heavy metal removal agent and a preparation method and application thereof. The high-efficiency heavy metal removal agent is a nanoporous soil modified with sodium pyridinethioaminohydroxyl having a porous structure and a long-chain material. It has good stability and strong selective adsorption capacity for heavy metal elements. At the same time, it meets green environmental protection requirements and is conducive to large-scale promotion and application.

[0007] To achieve this object, the present invention adopts the following technical solutions:

[0008] In a first aspect, the present invention provides a method for preparing an efficient heavy metal removal agent, the preparation method comprising the following steps:

[0009] (1) mixing hot water and a synthesizing agent to obtain a synthesizing agent solution;

[0010] (2) adding nano-porous clay, pyridine, a catalyst promoter and p-toluenesulfonic acid to the synthesis agent solution, stirring for a first period of time, then adding a sodium hydroxide solution of a first concentration, and continuing to stir for a second period of time to obtain a premix;

[0011] (3) mixing the premix and the sodium hydroxide solution of the second concentration for alkali salt absorption to obtain a first intermediate material, wherein the second concentration is lower than the first concentration;

[0012] (4) adding the sodium thioate complex dropwise to the first intermediate material for a reaction to obtain a second intermediate material;

[0013] (5) adding a crosslinking agent and a stabilizer to the second intermediate material for secondary reaction, and obtaining the high-efficiency heavy metal removal agent after solid-liquid separation.

[0014] Wherein, the cross-linking agent in step (5) contains a hydroxyl group, and the stabilizer contains an amino group.

[0015] The invention uses nano-porous soil as a raw material, and sequentially undergoes premixing, alkali salt absorption, primary reaction and secondary reaction to finally prepare pyridinethioaminohydroxy sodium modified nano-porous soil with a porous structure and long-chain material. The modified nano-porous soil has higher specific surface area and porosity, can more effectively adsorb heavy metal elements, and enhances the selective adsorption capacity for specific heavy metal elements. The addition of a cross-linking agent and a stabilizer improves the chemical and physical stability of the product, and it is not easy to aggregate or precipitate in a liquid environment, which helps to improve its long-term effectiveness in practical applications, meets green environmental protection requirements, and is conducive to large-scale promotion and application.

[0016] Preferably, the temperature of the hot water in step (1) is 30-40°C, for example, it can be 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0017] Preferably, the synthesizing agent in step (1) comprises any one of calcium polysulfide, sodium metaphosphate or sodium dihydrogen phosphate, or a combination of at least two thereof. Typical but non-limiting combinations include a combination of calcium polysulfide and sodium metaphosphate, a combination of sodium metaphosphate and sodium dihydrogen phosphate, a combination of calcium polysulfide and sodium dihydrogen phosphate, or a combination of calcium polysulfide, sodium metaphosphate and sodium dihydrogen phosphate.

[0018] Preferably, the concentration of the synthetic agent solution in step (1) is 30-50wt%, for example, 30wt%, 32wt%, 34wt%, 36wt%, 38wt%, 40wt%, 42wt%, 44wt%, 46wt%, 48wt% or 50wt%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0019] Preferably, the catalyst promoter in step (2) comprises an iron catalyst.

[0020] Preferably, the mixing mass ratio of the nanoporous soil and pyridine in step (2) is 3.5:(1.1-1.3), for example, it can be 3.5:1.1, 3.5:1.12, 3.5:1.14, 3.5:1.16, 3.5:1.18, 3.5:1.2, 3.5:1.22, 3.5:1.24, 3.5:1.26, 3.5:1.28 or 3.5:1.3, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0021] Preferably, the amount of the co-catalyst and p-toluenesulfonic acid in step (2) is 0.2%-1% of the mass of pyridine, for example, 0.2%, 0.3%, 0.4%, 0.5%, 0.6%, 0.7%, 0.8%, 0.9% or 1%, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0022] Preferably, in step (2), the first time period is 15-25 min, for example, it can be 15 min, 16 min, 17 min, 18 min, 19 min, 20 min, 21 min, 22 min, 23 min, 24 min or 25 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0023] Preferably, in step (2), the first concentration is 25-35wt%, for example, it can be 25wt%, 26wt%, 27wt%, 28wt%, 29wt%, 30wt%, 31wt%, 32wt%, 33wt%, 34wt% or 35wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0024] Preferably, the second time period in step (2) is 25-35 min, for example, it can be 25 min, 26 min, 27 min, 28 min, 29 min, 30 min, 31 min, 32 min, 33 min, 34 min or 35 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0025] Preferably, in step (3), the second concentration is 15-25wt%, for example, it can be 15wt%, 16wt%, 17wt%, 18wt%, 19wt%, 20wt%, 21wt%, 22wt%, 23wt%, 24wt% or 25wt%, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0026] Preferably, the sum of the masses of sodium hydroxide in the sodium hydroxide solution of the first concentration in step (2) and the sodium hydroxide solution of the second concentration in step (3) is 1.80-2.07 times the mass of pyridine, for example, it can be 1.80 times, 1.82 times, 1.84 times, 1.86 times, 1.88 times, 1.90 times, 1.92 times, 1.94 times, 1.96 times, 1.98 times, 2.00 times, 2.02 times, 2.04 times, 2.06 times or 2.07 times, but is not limited to the listed values, and other unlisted values ​​within the numerical range are equally applicable.

[0027] Preferably, the sodium thio complex in step (4) comprises trisodium thiocyanate and / or sodium dimethyldithiocarbamate.

[0028] Preferably, the amount of the sodium thio complex added in step (4) is 50-100 mg / L, for example, 50 mg / L, 55 mg / L, 60 mg / L, 65 mg / L, 70 mg / L, 75 mg / L, 80 mg / L, 85 mg / L, 90 mg / L, 95 mg / L or 100 mg / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0029] In the present invention, the dripping amount of the sodium thio complex is specifically: the specific dripping mass of the sodium thio complex relative to 1L of the first intermediate material.

[0030] Preferably, the temperature of the primary reaction in step (4) is 30-40°C, for example, it can be 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0031] Preferably, the primary reaction in step (4) is accompanied by stirring, and the stirring time is 50-60 min, for example, it can be 50 min, 51 min, 52 min, 53 min, 54 min, 55 min, 56 min, 57 min, 58 min, 59 min or 60 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0032] Preferably, the cross-linking agent in step (5) includes 4'-hydroxywogonin.

[0033] Preferably, the amount of the cross-linking agent added in step (5) is 20-60 mg / L, for example, 20 mg / L, 25 mg / L, 30 mg / L, 35 mg / L, 40 mg / L, 45 mg / L, 50 mg / L, 55 mg / L or 60 mg / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0034] In the present invention, the amount of the cross-linking agent added is specifically: the specific amount of the cross-linking agent added relative to 1L of the second intermediate material.

[0035] Preferably, the stabilizer in step (5) comprises 6-aminocaproic acid.

[0036] Preferably, the amount of the stabilizer added in step (5) is 50-80 mg / L, for example, 50 mg / L, 55 mg / L, 60 mg / L, 65 mg / L, 70 mg / L, 75 mg / L or 80 mg / L, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0037] In the present invention, the amount of the stabilizer added is specifically: the specific amount of the stabilizer added relative to 1L of the second intermediate material.

[0038] Preferably, the temperature of the secondary reaction in step (5) is 30-40°C, for example, 30°C, 31°C, 32°C, 33°C, 34°C, 35°C, 36°C, 37°C, 38°C, 39°C or 40°C, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0039] Preferably, the secondary reaction in step (5) is accompanied by stirring, and the stirring time is 50-60 min, for example, it can be 50 min, 51 min, 52 min, 53 min, 54 min, 55 min, 56 min, 57 min, 58 min, 59 min or 60 min, but is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0040] As a preferred technical solution of the first aspect of the present invention, the preparation method comprises the following steps:

[0041] (1) mixing hot water at 30-40° C. with a synthesizing agent to obtain a synthesizing agent solution with a concentration of 30-50 wt %; the synthesizing agent comprises any one of calcium polysulfide, sodium metaphosphate or sodium dihydrogen phosphate or a combination of at least two thereof;

[0042] (2) adding nano-orange pore soil, pyridine, iron catalyst and p-toluenesulfonic acid to the synthesis agent solution, stirring for 15-25 minutes, then adding 25-35wt% sodium hydroxide solution, and continuing to stir for 25-35 minutes to obtain a premix; the mixing mass ratio of the nano-orange pore soil and pyridine is 3.5:(1.1-1.3); the iron catalyst and p-toluenesulfonic acid are 0.2%-1% of the mass of pyridine respectively;

[0043] (3) mixing the premix and a 15-25wt% sodium hydroxide solution for alkali salt absorption to obtain a first intermediate material; the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is 1.80-2.07 times the mass of pyridine;

[0044] (4) adding trisodium thiocyanate and / or sodium dimethyldithiocarbamate dropwise to the first intermediate material, and controlling the addition amount to be 50-100 mg / L, and performing a reaction at 30-40° C., accompanied by stirring for 50-60 min, to obtain a second intermediate material;

[0045] (5) Add 4'-hydroxy wogonin and 6-aminocaproic acid to the second intermediate material, and control the addition amount of 4'-hydroxy wogonin to 20-60 mg / L and the addition amount of 6-aminocaproic acid to 50-80 mg / L, and carry out a secondary reaction at 30-40° C., accompanied by stirring for 50-60 minutes, and obtain the efficient heavy metal removal agent after solid-liquid separation.

[0046] In a second aspect, the present invention provides a high-efficiency heavy metal removal agent prepared by the preparation method described in the first aspect, wherein the high-efficiency heavy metal removal agent is a nanoporous soil modified with sodium pyridinethioaminohydroxyl having a porous structure and a long-chain material.

[0047] In a third aspect, the present invention provides an application of the high-efficiency heavy metal removal agent as described in the second aspect, wherein the high-efficiency heavy metal removal agent is used to remove heavy metal elements in water or soil.

[0048] The numerical range described in the present invention not only includes the point values ​​listed above, but also includes any point values ​​between the above numerical ranges that are not listed. Due to space limitations and for the sake of simplicity, the present invention no longer exhaustively lists the specific point values ​​included in the range.

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

[0050] The invention uses nano-porous soil as a raw material, and sequentially undergoes premixing, alkali salt absorption, primary reaction and secondary reaction to finally prepare pyridinethioaminohydroxy sodium modified nano-porous soil with a porous structure and long-chain material. The modified nano-porous soil has higher specific surface area and porosity, can more effectively adsorb heavy metal elements, and enhances the selective adsorption capacity for specific heavy metal elements. The addition of a cross-linking agent and a stabilizer improves the chemical and physical stability of the product, and it is not easy to aggregate or precipitate in a liquid environment, which helps to improve its long-term effectiveness in practical applications, meets green environmental protection requirements, and is conducive to large-scale promotion and application. DETAILED DESCRIPTION

[0051] The technical solution of the present invention is further illustrated below through specific implementation methods.

[0052] Example 1

[0053] This embodiment provides a high-efficiency heavy metal removal agent and a preparation method thereof, the preparation method comprising the following steps:

[0054] (1) mixing hot water at 35° C. and calcium polysulfide to obtain a synthetic agent solution with a concentration of 30 wt %;

[0055] (2) adding nano-orange pore soil, pyridine, iron catalyst and p-toluenesulfonic acid to the synthesis agent solution, stirring for 20 minutes, then adding 30wt% sodium hydroxide solution, and continuing to stir for 30 minutes to obtain a premix; the mixing mass ratio of the nano-orange pore soil and pyridine is 3.5:1.2; the iron catalyst and p-toluenesulfonic acid are 0.6% of the mass of pyridine respectively;

[0056] (3) mixing the premix and a 20 wt% sodium hydroxide solution for alkali salt absorption to obtain a first intermediate material; the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is 1.95 times the mass of pyridine;

[0057] (4) adding trisodium thiocyanate solution to the first intermediate material, and controlling the amount of addition to be 70 mg / L, and performing a reaction at 35° C. while stirring for 55 minutes to obtain a second intermediate material;

[0058] (5) Add 4'-hydroxy baicalin solution and 6-aminocaproic acid solution to the second intermediate material, and control the addition amount of 4'-hydroxy baicalin to 40 mg / L and the addition amount of 6-aminocaproic acid to 60 mg / L, and carry out a secondary reaction at 35° C. with stirring for 55 minutes, and then filter and dry to obtain the efficient heavy metal removal agent.

[0059] Example 2

[0060] This embodiment provides a high-efficiency heavy metal removal agent and a preparation method thereof, the preparation method comprising the following steps:

[0061] (1) mixing 30° C. hot water and sodium metaphosphate to obtain a synthetic agent solution with a concentration of 40 wt %;

[0062] (2) adding nano-orange pore soil, pyridine, iron catalyst and p-toluenesulfonic acid to the synthesis agent solution, stirring for 25 minutes, then adding 25wt% sodium hydroxide solution, and continuing to stir for 35 minutes to obtain a premix; the mixing mass ratio of the nano-orange pore soil and pyridine is 3.5:1.1; the iron catalyst and p-toluenesulfonic acid are 0.2% of the mass of pyridine respectively;

[0063] (3) mixing the premix and a 15 wt % sodium hydroxide solution for alkali salt absorption to obtain a first intermediate material; the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is 1.80 times the mass of pyridine;

[0064] (4) adding sodium dimethyldithiocarbamate solution to the first intermediate material, and controlling the amount of addition to be 50 mg / L, and performing a reaction at 30° C. while stirring for 60 min to obtain a second intermediate material;

[0065] (5) Add 4'-hydroxy wogonin solution and 6-aminocaproic acid solution to the second intermediate material, and control the addition amount of 4'-hydroxy wogonin to 20 mg / L and the addition amount of 6-aminocaproic acid to 50 mg / L, and carry out a secondary reaction at 30° C. with stirring for 60 minutes, and then filter and dry to obtain the efficient heavy metal removal agent.

[0066] Example 3

[0067] This embodiment provides a high-efficiency heavy metal removal agent and a preparation method thereof, the preparation method comprising the following steps:

[0068] (1) mixing 40° C. hot water and sodium dihydrogen phosphate to obtain a synthetic agent solution with a concentration of 50 wt %;

[0069] (2) adding nano-orange pore soil, pyridine, iron catalyst and p-toluenesulfonic acid to the synthesis agent solution, stirring for 15 minutes, then adding 35wt% sodium hydroxide solution, and continuing to stir for 25 minutes to obtain a premix; the mixing mass ratio of the nano-orange pore soil and pyridine is 3.5:1.3; the iron catalyst and p-toluenesulfonic acid are 1% of the mass of pyridine respectively;

[0070] (3) mixing the premix and a 25 wt% sodium hydroxide solution for alkali salt absorption to obtain a first intermediate material; the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is 2.07 times the mass of pyridine;

[0071] (4) adding trisodium thiocyanate solution to the first intermediate material, and controlling the amount of addition to be 100 mg / L, and performing a reaction at 40° C. while stirring for 50 minutes to obtain a second intermediate material;

[0072] (5) Add 4'-hydroxy baicalin solution and 6-aminocaproic acid solution to the second intermediate material, and control the addition amount of 4'-hydroxy baicalin to 60 mg / L and the addition amount of 6-aminocaproic acid to 80 mg / L, and carry out a secondary reaction at 40° C. while stirring for 50 minutes, and then filter and dry to obtain the efficient heavy metal removal agent.

[0073] Example 4

[0074] This embodiment provides an efficient heavy metal removal agent and a preparation method thereof. Except that the mixing mass ratio of nanoporous clay and pyridine in step (2) is changed to 3.5:0.8, the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0075] Example 5

[0076] This embodiment provides an efficient heavy metal removal agent and a preparation method thereof. Except that the mixing mass ratio of nanoporous clay and pyridine in step (2) is changed to 3.5:1.5, the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0077] Example 6

[0078] This embodiment provides a highly efficient heavy metal removal agent and a preparation method thereof. Except that the iron catalyst and p-toluenesulfonic acid in step (2) are respectively changed to 0.1% of the mass of pyridine, the remaining steps and conditions are the same as those in Example 1 and are not described in detail here.

[0079] Example 7

[0080] This embodiment provides a highly efficient heavy metal removal agent and a preparation method thereof. Except that the iron catalyst and p-toluenesulfonic acid in step (2) are respectively changed to 2% of the mass of pyridine, the remaining steps and conditions are the same as those in Example 1 and are not described in detail here.

[0081] Example 8

[0082] The present embodiment provides a high-efficiency heavy metal removal agent and a preparation method thereof. Except that the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is changed to 1.60 times the mass of pyridine, the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0083] Example 9

[0084] This embodiment provides a high-efficiency heavy metal removal agent and a preparation method thereof. Except that the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is changed to 2.10 times the mass of pyridine, the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0085] Example 10

[0086] This embodiment provides a high-efficiency heavy metal removal agent and a preparation method thereof. Except that the addition amount of trisodium thiocyanate in step (4) is changed to 40 mg / L, the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0087] Embodiment 11

[0088] This embodiment provides a highly efficient heavy metal removal agent and a preparation method thereof. Except that the amount of 4'-hydroxywogonin added in step (5) is changed to 10 mg / L, the remaining steps and conditions are the same as those in Example 1 and are not described in detail here.

[0089] Example 12

[0090] This embodiment provides a highly efficient heavy metal removal agent and a preparation method thereof. Except that the addition amount of 6-aminocaproic acid in step (5) is changed to 40 mg / L, the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0091] Comparative Example 1

[0092] This comparative example provides a heavy metal removal agent and a preparation method thereof. Except that pyridine is not added in step (2), the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0093] Comparative Example 2

[0094] This comparative example provides a heavy metal removal agent and a preparation method thereof. Except that the primary reaction described in step (4) is not performed, that is, a cross-linking agent and a stabilizer are directly added to the first intermediate material for a secondary reaction, the remaining steps and conditions are the same as those in Example 1 and are not described in detail here.

[0095] Comparative Example 3

[0096] This comparative example provides a heavy metal removal agent and a preparation method thereof. Except that 4'-hydroxywogonin is not added dropwise in step (5), the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0097] Comparative Example 4

[0098] This comparative example provides a heavy metal removal agent and a preparation method thereof. Except that 6-aminocaproic acid is not added dropwise in step (5), the remaining steps and conditions are the same as those in Example 1, and thus are not described in detail here.

[0099] Comparative Example 5

[0100] This comparative example provides a heavy metal removal agent and a preparation method thereof. Except that the secondary reaction described in step (5) is not performed, that is, the second intermediate material is directly filtered and dried and then used as the heavy metal removal agent, the remaining steps and conditions are the same as those in Example 1, so they are not repeated here.

[0101] Performance Testing

[0102] According to Table 1 below, 17 groups of 1L sewage samples containing heavy metal elements were prepared, and the heavy metal removal agents obtained in Examples 1-12 and Comparative Examples 1-5 were added to the above 17 groups of sewage samples respectively, and the added amount was 10 g. The heavy metal removal agents were fully stirred to make them suspended and in full contact with the sewage samples. After stirring for 5 hours, the concentration of remaining heavy metal elements in the sewage samples was detected. The relevant physical properties of the heavy metal removal agents and the heavy metal removal detection results are shown in Table 2 below.

[0103] Table 1

[0104] Heavy Metal Elements Pb Hg Cd Cr Concentration (mg / L) 5 0.01 0.5 5

[0105] Table 2

[0106]

[0107]

[0108] It can be seen that the present invention uses nano-porous soil as raw material, and successively undergoes premixing, alkali salt absorption, primary reaction and secondary reaction to finally prepare pyridinethioaminohydroxy sodium modified nano-porous soil with a porous structure and long-chain material. The modified nano-porous soil has higher specific surface area and porosity, can more effectively adsorb heavy metal elements, and enhances the selective adsorption capacity for specific heavy metal elements; the addition of cross-linking agent and stabilizer improves the chemical and physical stability of the product, and it is not easy to aggregate or precipitate in a liquid environment, which helps to improve its long-term effectiveness in practical applications, and at the same time meets green environmental protection requirements, which is conducive to large-scale promotion and application.

[0109] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for preparing an efficient heavy metal removal agent, It is characterized in that The preparation method comprises the following steps: (1) mixing hot water and a synthesizing agent to obtain a synthesizing agent solution; (2) adding nano-porous clay, pyridine, a catalyst promoter and p-toluenesulfonic acid to the synthesis agent solution, stirring for a first period of time, then adding a sodium hydroxide solution of a first concentration, and continuing to stir for a second period of time to obtain a premix; (3) mixing the premix and the sodium hydroxide solution of the second concentration for alkali salt absorption to obtain a first intermediate material, wherein the second concentration is lower than the first concentration; (4) adding the sodium thioate complex dropwise to the first intermediate material for a reaction to obtain a second intermediate material; (5) adding a crosslinking agent and a stabilizer to the second intermediate material for secondary reaction, and obtaining the efficient heavy metal removal agent after solid-liquid separation; Wherein, the cross-linking agent in step (5) contains a hydroxyl group, and the stabilizer contains an amino group.

2. The preparation method according to claim 1, It is characterized in that The temperature of the hot water in step (1) is 30-40° C. Preferably, the synthesis agent in step (1) comprises any one of calcium polysulfide, sodium metaphosphate or sodium dihydrogen phosphate, or a combination of at least two thereof; Preferably, the concentration of the synthesis agent solution in step (1) is 30-50wt%.

3. The preparation method according to claim 1 or 2, It is characterized in that The auxiliary catalyst in step (2) includes an iron catalyst; Preferably, the mixing mass ratio of the nano-porous clay and pyridine in step (2) is 3.5:(1.1-1.3); Preferably, the catalyst promoter and p-toluenesulfonic acid in step (2) are 0.2%-1% of the mass of pyridine respectively.

4. The preparation method according to any one of claims 1 to 3, It is characterized in that Step (2) the first time period is 15-25 minutes; Preferably, in step (2), the first concentration is 25-35 wt %; Preferably, in step (2), the second time period is 25-35 minutes.

5. The preparation method according to any one of claims 1 to 4, It is characterized in that Step (3) the second concentration is 15-25wt%; Preferably, the sum of the mass of sodium hydroxide in the sodium hydroxide solution of the first concentration in step (2) and the sodium hydroxide solution of the second concentration in step (3) is 1.80-2.07 times the mass of pyridine.

6. The preparation method according to any one of claims 1 to 5, It is characterized in that The sodium thio complex in step (4) comprises trisodium thiocyanate and / or sodium dimethyldithiocarbamate; Preferably, the amount of the sodium thio complex added in step (4) is 50-100 mg / L; Preferably, the temperature of the primary reaction in step (4) is 30-40°C; Preferably, the primary reaction in step (4) is accompanied by stirring, and the stirring time is 50-60 min.

7. The preparation method according to any one of claims 1 to 6, It is characterized in that The cross-linking agent in step (5) includes 4'-hydroxywogonin; Preferably, the amount of the cross-linking agent added in step (5) is 20-60 mg / L; Preferably, the stabilizer in step (5) comprises 6-aminocaproic acid; Preferably, the amount of the stabilizer added in step (5) is 50-80 mg / L; Preferably, the temperature of the secondary reaction in step (5) is 30-40°C; Preferably, the secondary reaction in step (5) is accompanied by stirring, and the stirring time is 50-60 min.

8. The preparation method according to any one of claims 1 to 7, It is characterized in that The preparation method comprises the following steps: (1) mixing hot water at 30-40° C. with a synthesizing agent to obtain a synthesizing agent solution with a concentration of 30-50 wt %; the synthesizing agent comprises any one of calcium polysulfide, sodium metaphosphate or sodium dihydrogen phosphate or a combination of at least two thereof; (2) adding nano-orange pore soil, pyridine, iron catalyst and p-toluenesulfonic acid to the synthesis agent solution, stirring for 15-25 minutes, then adding 25-35wt% sodium hydroxide solution, and continuing to stir for 25-35 minutes to obtain a premix; the mixing mass ratio of the nano-orange pore soil and pyridine is 3.5:(1.1-1.3); the iron catalyst and p-toluenesulfonic acid are 0.2%-1% of the mass of pyridine respectively; (3) mixing the premix and a 15-25wt% sodium hydroxide solution for alkali salt absorption to obtain a first intermediate material; the sum of the mass of sodium hydroxide in the sodium hydroxide solution in step (2) and the sodium hydroxide solution in step (3) is 1.80-2.07 times the mass of pyridine; (4) adding trisodium thiocyanate and / or sodium dimethyldithiocarbamate dropwise to the first intermediate material, and controlling the addition amount to be 50-100 mg / L, and performing a reaction at 30-40° C., accompanied by stirring for 50-60 min, to obtain a second intermediate material; (5) Add 4'-hydroxy wogonin and 6-aminocaproic acid to the second intermediate material, and control the addition amount of 4'-hydroxy wogonin to 20-60 mg / L and the addition amount of 6-aminocaproic acid to 50-80 mg / L, and carry out a secondary reaction at 30-40° C., accompanied by stirring for 50-60 minutes, and obtain the efficient heavy metal removal agent after solid-liquid separation.

9. An efficient heavy metal removal agent prepared by the preparation method according to any one of claims 1 to 8, It is characterized in that The high-efficiency heavy metal removal agent is a nanoporous soil modified with sodium pyridinethioaminohydroxyl having a porous structure and a long-chain material.

10. Use of the efficient heavy metal removal agent as claimed in claim 9, It is characterized in that The high-efficiency heavy metal removal agent is used for removing heavy metal elements in water or soil.

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