Selective adsorption material for treating selenium-containing wastewater, preparation method therefor, and method using same for treating selenium-containing wastewater

Abstract

The present application relates to the field of wastewater treatment. Provided are a selective adsorption material for treating selenium-containing wastewater, a preparation method therefor, and a method using same for treating selenium-containing wastewater.The preparation method comprises: thermally treating active charcoal by using nitric acid, washing same to be neutral, and carrying out constant-temperature drying to obtain modified active charcoal; mixing magnesium chloride, ethanol, dodecyl trimethyl ammonium chloride and 2-mercaptoethanol to obtain a loading solution; mixing the modified active charcoal, the loading solution and sulfosuccinimidyl 4-(maleimidomethyl)cyclohexane-1-carboxylate sodium salt, adding ammonium hydroxide to regulate the pH value of the solution to 10-11, and then sequentially carrying out first heating treatment and second heating treatment to obtain a primary adsorption material; and cleaning the primary adsorption material, and then performing vacuum drying. The material prepared by the method provided in the present application can enable treated wastewater to reach the primary standard limit value (0.1 mg / L) of integrated wastewater discharge standard, and has high adsorption efficiency and low treatment cost.

Description

A selective adsorption material for treating selenium-containing wastewater, a preparation method thereof, and a method for treating selenium-containing wastewater using the same Technical Field

[0001] The present application relates to the field of wastewater treatment, and in particular to a selective adsorption material for treating selenium-containing wastewater, a preparation method thereof, and a method for treating selenium-containing wastewater using the same. Background Art

[0002] In recent years, the discharge of selenium-containing wastewater has received increasing attention, putting increasing pressure on related companies to meet emission standards. Currently, companies typically use chemical precipitation methods for treatment, but this method suffers from unstable treatment results and the inability to consistently meet standards. Advanced treatment using commonly used adsorption materials on the market can also present challenges such as poor adsorption selectivity, unstable treatment results, low adsorption capacity, frequent regeneration leading to reduced service life, and high costs.

[0003] Developing an adsorption material with good selectivity, large adsorption capacity, good stability, no need for frequent regeneration and long service life for selenium-containing wastewater has become an urgent problem to be solved.

[0004] Summary of the Invention

[0005] The purpose of this application is to provide a selective adsorption material for treating selenium-containing wastewater, a preparation method thereof, and a method for treating selenium-containing wastewater using the same, so as to solve the above problems.

[0006] To achieve the above objectives, this application adopts the following technical solutions:

[0007] A method for preparing a selective adsorption material for treating selenium-containing wastewater, comprising:

[0008] The activated carbon is heat-treated with nitric acid at 50-80°C for 2-3 hours, washed to neutrality, and dried at a constant temperature of 80-110°C to obtain modified activated carbon;

[0009] Mixing magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol to obtain a loading solution;

[0010] The modified activated carbon, the loaded solution, and 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt are mixed, ammonia water is added to adjust the pH of the solution to 10-11, and then a first heating treatment and a second heating treatment are sequentially performed to obtain a primary adsorption material; the first heating treatment temperature is 60-80° C. and the time is 30-45 minutes; the second heating treatment temperature is 100-120° C. and the time is 8-12 hours;

[0011] The primary adsorption material is washed and then vacuum-dried at 60-80° C. for 12-18 hours to obtain the selective adsorption material for treating selenium-containing wastewater.

[0012] Preferably, the mass volume ratio of the activated carbon to the nitric acid is 5 g: (10-20) mL;

[0013] The particle size of the activated carbon is 20-50 meshes.

[0014] Preferably, the mass volume ratio of the magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol is 1 g: (60-80) mL: (0.1-0.5) g: (0.2-0.5) ml.

[0015] Preferably, the volume fraction of the ammonia water is 10-15%;

[0016] The sodium salt of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester is pre-configured into an aqueous solution with a mass fraction of 12%-18% for use.

[0017] Preferably, the mass volume ratio of the activated carbon, the loading solution, and the 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt cross-linking agent is 5 g: (40-60) mL: (30-40) mL.

[0018] Preferably, the cleaning comprises: repeatedly cleaning the primary adsorption material with deionized water and ethanol for 45-60 minutes.

[0019] The present application also provides a selective adsorption material for treating selenium-containing wastewater, which is prepared using the preparation method of the selective adsorption material for treating selenium-containing wastewater.

[0020] Preferably, in the selective adsorption material for treating selenium-containing wastewater, the material with a particle size of 0.3-0.85 mm accounts for greater than or equal to 98 wt %.

[0021] The present application also provides a method for treating selenium-containing wastewater using the selective adsorption material for treating selenium-containing wastewater, comprising:

[0022] The selective adsorption material for treating selenium-containing wastewater is mixed with the selenium-containing wastewater.

[0023] Preferably, the pH of the system is 6-10.

[0024] Compared with the prior art, the advantages of this application include:

[0025] The present application provides a method for preparing a selective adsorption material for treating selenium-containing wastewater. During the preparation process, the activated carbon is first pre-treated with acid to expand the pores, which is beneficial to the transfer and diffusion of ions and the loading of more selective adsorption particles in the pores during the adsorption process. After loading magnesium, it is treated with ammonia water to form a hydrated oxide with a special magnesium metal-hydroxyl group. Through surface complexation, the adsorption selectivity of selenite is improved; at the same time, quaternary amino groups and thiol groups are also loaded, and the selectivity for selenate is increased through coordination. Compared with other adsorbents on the market, it has a different separation principle. The adsorption treatment of heavy metals in this application mainly relies on the hydroxyl groups of hydrated hydroxy magnesium oxide, as well as the adsorption of quaternary amino groups and thiol groups.

[0026] The selective adsorption material for treating selenium-containing wastewater provided in the present application has good selectivity, large adsorption capacity, good stability, no need for frequent regeneration, and long service life.

[0027] The selective adsorption material for treating selenium-containing wastewater provided in the present application can be used to treat selenium-containing wastewater, which can meet the first-level comprehensive sewage discharge standard (0.1 mg / L) with high adsorption efficiency and low treatment cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0029] FIG1 is a scanning electron microscope photograph of the selective adsorption material for treating selenium-containing wastewater obtained in Example 1;

[0030] FIG2 is an infrared spectrum of the selective adsorption material for treating selenium-containing wastewater obtained in Example 1. DETAILED DESCRIPTION

[0031] As used herein:

[0032] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0033] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0034] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0035] In these examples, parts and percentages are by mass unless otherwise indicated.

[0036] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the mass of all components is not limited to 100 parts.

[0037] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0038] A method for preparing a selective adsorption material for treating selenium-containing wastewater, comprising:

[0039] The activated carbon is heat-treated with nitric acid at 50-80°C for 2-3 hours, washed to neutrality, and dried at a constant temperature of 80-110°C to obtain modified activated carbon;

[0040] Mixing magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol to obtain a loading solution;

[0041] The modified activated carbon, the loaded solution, and 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt are mixed, ammonia water is added to adjust the pH of the solution to 10-11, and then a first heating treatment and a second heating treatment are sequentially performed to obtain a primary adsorption material; the first heating treatment temperature is 60-80° C. and the time is 30-45 minutes; the second heating treatment temperature is 100-120° C. and the time is 8-12 hours;

[0042] The primary adsorption material is washed and then vacuum-dried at 60-80° C. for 12-18 hours to obtain the selective adsorption material for treating selenium-containing wastewater.

[0043] Optionally, the temperature of the heat treatment can be 50°C, 60°C, 70°C, 80°C or any value between 50°C and 80°C, and the time can be 2h, 2.5h, 3h or any value between 2-3h; the temperature of the constant temperature drying can be 80°C, 90°C, 100°C, 110°C or any value between 80°C and 110°C; the pH of the solution adjusted by adding ammonia water can be 10, 11 or any value between 10-11; the temperature of the first heat treatment can be 60°C, 70°C, 80°C or any value between 60-80°C , and the time can be 30min, 35min, 40min, 45min or any value between 30-45min; the temperature of the second heat treatment can be 100℃, 110℃, 120℃ or any value between 100-120℃, and the time can be 8h, 10h, 12h or any value between 8-12h; the temperature of the vacuum drying can be 60℃, 70℃, 80℃ or any value between 60-80℃, and the time can be 12h, 14h, 16h, 18h or any value between 12-18h.

[0044] In an optional embodiment, the mass volume ratio of the activated carbon to the nitric acid is 5 g: (10-20) mL;

[0045] Optionally, the mass volume ratio of the activated carbon to the nitric acid can be any value between 5g:10mL, 5g:15mL, 5g:20mL or 5g:(10-20)mL;

[0046] The particle size of the activated carbon is 20-50 meshes.

[0047] Optionally, the particle size of the activated carbon can be 20 mesh, 30 mesh, 40 mesh, 50 mesh or any value between 20-50 mesh.

[0048] In an optional embodiment, the mass volume ratio of the mixture of magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol is 1 g: (60-80) mL: (0.1-0.5) g: (0.2-0.5) ml.

[0049] Optionally, the mass volume ratio of the magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol can be 1g:60mL:0.1g:0.2mL; 1g:60mL:0.1g:0.5mL; 1g:60mL:0.5g:0.2mL; 1g:60mL:0.5g:0.5mL; 1g:80mL:0.1g:0.2mL; 1g:80mL:0.1g:0.5mL; 1g:80mL:0.5g:0.2mL; 1g:80mL:0.5g:0.5mL; or 1g:(60-80)mL:(0.1-0.5)g:(0.2-0.5)mL.

[0050] In an optional embodiment, the volume fraction of the ammonia water is 10-15%;

[0051] The sodium salt of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester is pre-configured into an aqueous solution with a mass fraction of 12%-18% for use.

[0052] Optionally, the volume fraction of the ammonia water may be 10%, 11%, 12%, 13%, 14%, 15%, or any value between 10-15%; the mass fraction of the sodium salt of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester pre-configured may be 12%, 13%, 14%, 15%, 16%, 17%, 18%, or any value between 12-18%;

[0053] In an optional embodiment, the mass volume ratio of the activated carbon, the loading solution, and the 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfonic acid succinimide ester sodium salt cross-linking agent is 5 g: (40-60) mL: (30-40) mL.

[0054] Optionally, the mass volume ratio of the activated carbon, the loaded solution, and the 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfonic acid succinimide ester sodium salt cross-linker can be any value between 5g:40mL:30mL, 5g:40mL:40mL, 5g:60mL:30mL, 5g:60mL:40mL or 5g:(40-60)mL:(30-40)mL.

[0055] In an optional embodiment, the cleaning comprises: repeatedly cleaning the primary adsorption material with deionized water and ethanol for 45-60 minutes.

[0056] Optionally, the time for repeatedly washing the primary adsorption material with deionized water and ethanol can be 45 min, 50 min, 55 min, 60 min or any value between 45 and 60 min.

[0057] The present application also provides a selective adsorption material for treating selenium-containing wastewater, which is prepared using the preparation method of the selective adsorption material for treating selenium-containing wastewater.

[0058] In an optional embodiment, in the selective adsorption material for treating selenium-containing wastewater, the material with a particle size of 0.3-0.85 mm accounts for greater than or equal to 98 wt %.

[0059] The present application also provides a method for treating selenium-containing wastewater using the selective adsorption material for treating selenium-containing wastewater, comprising:

[0060] The selective adsorption material for treating selenium-containing wastewater is mixed with the selenium-containing wastewater.

[0061] In an optional embodiment, the pH of the system is 6-10.

[0062] Optionally, when treating wastewater, the pH of the system can be 6, 7, 8, 9, 10 or any value between 6 and 10.

[0063] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are merely illustrative of the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, the conditions are carried out according to conventional conditions or manufacturer recommendations. The reagents or instruments used are not specified by the manufacturer and are conventional products that can be purchased commercially.

[0064] This embodiment provides a selective adsorption material for treating selenium-containing wastewater, and the preparation method thereof is as follows:

[0065] 1) Add 15 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 60° C., stir for 2 h, cool, filter, wash the activated carbon with water to pH = 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0066] 2) Magnesium chloride, ethanol, dodecyltrimethylammonium chloride, and 2-mercaptoethanol were prepared in a ratio of 1 g:60 mL:0.2 g:0.3 mL, and stirred for 30 minutes to fully dissolve and mix to form a loading solution.

[0067] 3) The modified activated carbon, the loading solution, and a 15% (by mass) crosslinker of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt were mixed in a ratio of 5 g:50 mL:40 mL, stirred for 1 h, and 12% ammonia water was added to adjust the solution pH to 10 to form Preparation Solution 1.

[0068] 4) Heat the prepared solution 1 at 60° C. for 30 minutes to form the prepared solution 2.

[0069] 5) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 8 h to obtain a primary adsorption material.

[0070] 6) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 60° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0071] A scanning electron microscope photograph of the obtained selective adsorption material for treating selenium-containing wastewater is shown in Figure 1. The left figure is a scanning electron microscope photograph before modification, and the right figure is a scanning electron microscope photograph after modification.

[0072] Figure 2 is the infrared spectrum of the selective adsorption material for treating selenium-containing wastewater obtained in Example 1. -1 There is an obvious hydroxyl stretching vibration peak, and at 1682.1cm -1 The quaternary amino group vibration peak appears at 1370.2 cm -1 、860.4cm -1 The metal-hydroxyl vibration peak appeared at 2627.5 cm -1 The thiol vibration peak appears.

[0073] Selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater (test method: Determination of selenium in water by 2,3-diaminonaphthalene fluorescence method (GB 11902-89)). The pH of the system was 6. The treatment results are shown in Table 1 below:

[0074] Table 1 Example 1 Treatment results (unit mg / L)

[0075] As can be seen from Table 1, the selective adsorption material for selenium-containing wastewater is used to treat selenium-containing wastewater, and the selenium content after treatment can reach the first-level standard for comprehensive sewage discharge.

[0076] Example 2

[0077] This embodiment provides a selective adsorption material for treating selenium-containing wastewater, and the preparation method thereof is as follows:

[0078] 1) Add 20 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 80° C., stir for 2.5 h, cool, and filter. Wash the activated carbon with water to a pH of 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0079] 2) Magnesium chloride, ethanol, dodecyltrimethylammonium chloride, and 2-mercaptoethanol were prepared in a ratio of 1 g:60 mL:0.5 g:0.5 mL, and stirred for 30 minutes to fully dissolve and mix to form a loading solution.

[0080] 3) The modified activated carbon, the loading solution, and 18% by mass of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt crosslinker were mixed in a ratio of 5 g:60 mL:40 mL, stirred for 1 h, and 15% ammonia water was added to adjust the solution pH to 11 to form Preparation Solution 1.

[0081] 4) Heat the prepared solution 1 and carry out a heating reaction at a reaction temperature of 70° C. for 40 minutes to form a prepared solution 2.

[0082] 5) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 10 h to obtain a primary adsorption material.

[0083] 6) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 80° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0084] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 9. The treatment results are shown in Table 2 below:

[0085] Table 2 Example 2 Treatment results (unit mg / L)

[0086] As can be seen from Table 2, the selective adsorption material for selenium-containing wastewater is used to treat selenium-contaminated surface water, and the selenium content after treatment can meet the first-level standard for comprehensive sewage discharge.

[0087] Example 3

[0088] This embodiment provides a selective adsorption material for treating selenium-containing wastewater, and the preparation method thereof is as follows:

[0089] 1) Add 10 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 60° C., stir for 2 h, cool, filter, wash the activated carbon with water to pH = 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0090] 2) Magnesium chloride, ethanol, dodecyltrimethylammonium chloride, and 2-mercaptoethanol were prepared in a ratio of 1 g:60 ml:0.1 g:0.2 mL, and stirred for 30 minutes to fully dissolve and mix to form a loading solution.

[0091] 3) The modified activated carbon, the loading solution, and a 12% (by mass) crosslinker of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt were mixed in a ratio of 5 g:40 mL:30 mL, stirred for 1 h, and 10% ammonia water was added to adjust the solution pH to 10 to form Preparation Solution 1.

[0092] 4) Heat the prepared solution 1 at 60° C. for 30 minutes to form the prepared solution 2.

[0093] 5) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 8 h to obtain a primary adsorption material.

[0094] 6) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 70° C. for 16 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0095] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 10. The treatment results are shown in Table 3 below:

[0096] Table 3 Example 3 treatment results (unit mg / L)

[0097] As can be seen from Table 3, the selective adsorption material for selenium-containing wastewater is used to treat selenium-contaminated surface water, and the selenium content after treatment can meet the first-level standard for comprehensive sewage discharge.

[0098] Comparative Example 1

[0099] This comparative example provides a selective adsorption material for treating selenium-containing wastewater, and its preparation method is as follows:

[0100] 1) Prepare magnesium chloride, ethanol, dodecyltrimethylammonium chloride, and 2-mercaptoethanol in a ratio of 1 g:60 mL:0.2 g:0.3 mL, and stir for 30 minutes to fully dissolve and mix to form a loading solution.

[0101] 2) Activated carbon, the loading solution, and a 15% (by mass) crosslinker of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt were mixed in a ratio of 5 g:50 mL:40 mL. The mixture was stirred for 1 h, and 12% ammonia water was added to adjust the solution pH to 10 to form Preparation Solution 1.

[0102] 3) Heat the prepared solution 1 and carry out a heating reaction at a reaction temperature of 60° C. for 30 minutes to form a prepared solution 2.

[0103] 4) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 8 h to obtain a primary adsorption material.

[0104] 5) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 60° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0105] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 6. The treatment results are shown in Table 4 below:

[0106] Table 4 Comparative Example 1 Treatment Results (Unit: mg / L)

[0107] As can be seen from Table 4, the selective adsorption material for selenium-containing wastewater is used to treat selenium-contaminated surface water, and the selenium content after treatment cannot meet the first-level standard for comprehensive sewage discharge.

[0108] Comparative Example 2

[0109] This comparative example provides a selective adsorption material for treating selenium-containing wastewater, and its preparation method is as follows:

[0110] 1) Add 15 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 60° C., stir for 2 h, cool, filter, wash the activated carbon with water to pH = 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0111] 2) Take ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol in a ratio of 60 mL:0.2 g:0.3 mL, and stir for 30 minutes to fully dissolve and mix to form a loading solution.

[0112] 3) The modified activated carbon, the loading solution, and a 15% (by mass) crosslinker of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt were mixed in a ratio of 5 g:50 mL:40 mL, stirred for 1 h, and 12% ammonia water was added to adjust the solution pH to 10 to form Preparation Solution 1.

[0113] 4) Heat the prepared solution 1 at 60° C. for 30 minutes to form the prepared solution 2.

[0114] 5) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 8 h to obtain a primary adsorption material.

[0115] 6) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 60° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0116] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 6. The treatment results are shown in Table 5 below:

[0117] Table 5 Comparative Example 2 Treatment Results (Unit: mg / L)

[0118] As can be seen from Table 5, the selective adsorption material for selenium-containing wastewater in Comparative Example 2 was used to treat selenium-contaminated surface water, and the selenium content after treatment could not meet the first-level standard for comprehensive sewage discharge.

[0119] Comparative Example 3

[0120] This comparative example provides a selective adsorption material for treating selenium-containing wastewater, and its preparation method is as follows:

[0121] 1) Add 15 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 60° C., stir for 2 h, cool, filter, wash the activated carbon with water to pH = 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0122] 2) Prepare magnesium chloride and ethanol at a ratio of 1 g:60 mL and stir for 30 minutes to fully dissolve and mix to form a loading solution.

[0123] 3) The modified activated carbon, the loading solution, and a 15% (by mass) crosslinker of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt were mixed in a ratio of 5 g:50 mL:40 mL. The mixture was stirred for 1 h, and 12% ammonia water was added to adjust the solution pH to 10 to form Preparation Solution 1.

[0124] 4) Heat the prepared solution 1 at 60° C. for 30 minutes to form the prepared solution 2.

[0125] 5) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 8 h to obtain a primary adsorption material.

[0126] 6) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 60° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0127] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 6. The treatment results are shown in Table 6 below:

[0128] Table 6 Comparative Example 3 Treatment Results (Unit: mg / L)

[0129] As can be seen from Table 6, the selective adsorption material for selenium-containing wastewater in Comparative Example 3 was used to treat selenium-contaminated surface water, and the selenium content after treatment could not meet the first-level standard for comprehensive sewage discharge.

[0130] Comparative Example 4

[0131] This comparative example provides a selective adsorption material for treating selenium-containing wastewater, and its preparation method is as follows:

[0132] 1) Add 15 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 60° C., stir for 2 h, cool, filter, wash the activated carbon with water to pH = 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0133] 2) Magnesium chloride, ethanol, dodecyltrimethylammonium chloride, and 2-mercaptoethanol were prepared in a ratio of 1 g:60 mL:0.2 g:0.3 mL, and stirred for 30 minutes to fully dissolve and mix to form a loading solution.

[0134] 3) The modified activated carbon, the loading solution, and a 15% by mass ratio of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt crosslinker were mixed in a ratio of 5 g:50 mL:40 mL, and stirred for 1 hour to form Preparation Solution 1.

[0135] 4) Heat the prepared solution 1 and carry out a heating reaction at a reaction temperature of 60° C. for 30 minutes to form a prepared solution 2.

[0136] 5) The prepared solution 2 was heated and reacted at a reaction temperature of 120° C. for 8 h to obtain a primary adsorption material.

[0137] 6) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 60° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0138] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 6. The treatment results are shown in Table 7 below:

[0139] Table 7 Comparative Example 4 Treatment Results (Unit: mg / L)

[0140] As can be seen from Table 7, the selective adsorption material for selenium-containing wastewater in Comparative Example 4 was used to treat selenium-contaminated surface water, and the selenium content after treatment could not meet the first-level standard for comprehensive sewage discharge.

[0141] Comparative Example 5

[0142] This comparative example provides a selective adsorption material for treating selenium-containing wastewater, and its preparation method is as follows:

[0143] 1) Add 15 mL of nitric acid to 5 g of 20-mesh activated carbon, heat to 60° C., stir for 2 h, cool, filter, wash the activated carbon with water to pH = 7, and dry at a constant temperature of 110° C. to a constant weight to form modified activated carbon.

[0144] 2) Magnesium chloride, ethanol, dodecyltrimethylammonium chloride, and 2-mercaptoethanol were prepared in a ratio of 1 g:60 mL:0.2 g:0.3 mL, and stirred for 30 minutes to fully dissolve and mix to form a loading solution.

[0145] 3) The modified activated carbon, the loading solution, and a 15% mass fraction of 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfosuccinimide ester sodium salt crosslinker were mixed in a ratio of 5 g:50 mL:40 mL, stirred for 1 h, and 12% ammonia water was added to adjust the solution pH to 10.

[0146] 4) Repeatedly washing with deionized water and ethanol for 60 minutes to remove the solvent and unreacted substances; then placing in a vacuum drying oven at 60° C. for 18 hours to prepare a selective adsorption material for treating selenium-containing wastewater.

[0147] The selenium-containing wastewater was treated using the selective adsorption material for treating selenium-containing wastewater, and the pH of the system was 6. The treatment results are shown in Table 8 below:

[0148] Table 8 Comparative Example 5 Treatment Results (Unit: mg / L)

[0149] As can be seen from Table 8, the selective adsorption material for selenium-containing wastewater in Comparative Example 5 was used to treat selenium-contaminated surface water, and the selenium content after treatment could not meet the first-level standard for comprehensive sewage discharge.

[0150] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0151] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form distinct embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing a selective adsorption material for treating selenium-containing wastewater, characterized in that: include: The activated carbon is heat treated with nitric acid at 50°C-80°C for 2-3h, washed to neutrality, and dried at a constant temperature of 80-110°C to obtain modified activated carbon; Mixing magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol to obtain a loading solution; The modified activated carbon, the loading solution and 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfonic acid succinimide ester sodium salt are mixed, ammonia water is added to adjust the pH of the solution to 10-11, and then a first heating treatment and a second heating treatment are sequentially performed to obtain a primary adsorption material; the temperature of the first heating treatment is 60-80° C. and the time is 30-45 min; the temperature of the second heating treatment is 100-120° C. and the time is 8-12 h; The primary adsorption material is washed and then vacuum dried at 60-80° C. for 12-18 hours to obtain the selective adsorption material for treating selenium-containing wastewater.

2. The method for preparing a selective adsorption material for treating selenium-containing wastewater according to claim 1, characterized in that: The mass volume ratio of the activated carbon to the nitric acid is 5 g: (10-20) mL; The particle size of the activated carbon is 20-50 meshes.

3. The method for preparing a selective adsorption material for treating selenium-containing wastewater according to claim 1, characterized in that: The mass volume ratio of the magnesium chloride, ethanol, dodecyltrimethylammonium chloride and 2-mercaptoethanol is 1g: (60-80)mL: (0.1-0.5)g: (0.2-0.5)ml.

4. The method for preparing a selective adsorption material for treating selenium-containing wastewater according to claim 1, characterized in that: The volume fraction of the ammonia water is 10-15%; The 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfonic acid succinimide ester sodium salt is prepared First prepare it into an aqueous solution with a mass fraction of 12%-18% for use.

5. The method for preparing a selective adsorption material for treating selenium-containing wastewater according to claim 1, characterized in that: The mass volume ratio of the activated carbon, the loading solution, and the 4-(N-maleimidomethyl)cyclohexane-1-carboxylic acid sulfonic acid succinimide ester sodium salt cross-linking agent is 5g: (40-60) mL: (30-40) mL.

6. The method for preparing a selective adsorption material for treating selenium-containing wastewater according to any one of claims 1 to 5, characterized in that: The cleaning comprises: repeatedly cleaning the primary adsorption material with deionized water and ethanol for 45-60 minutes.

7. A selective adsorption material for treating selenium-containing wastewater, characterized in that: The selective adsorption material for treating selenium-containing wastewater is prepared using the preparation method of any one of claims 1 to 6.

8. The selective adsorption material for treating selenium-containing wastewater according to claim 7, characterized in that: In the selective adsorption material for treating selenium-containing wastewater, the material with a particle size of 0.3-0.85 mm accounts for greater than or equal to 98 wt %.

9. A method for treating selenium-containing wastewater using the selective adsorption material for treating selenium-containing wastewater according to claim 7 or 8, characterized in that: include: The selective adsorption material for treating selenium-containing wastewater is mixed with the selenium-containing wastewater.

10. The method according to claim 9, characterized in that The system pH is 6-10.

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