Efficient targeted adsorbent for treating perchlorate wastewater and preparation method and application thereof

Abstract

The application discloses a kind of efficient targeted adsorbent for treating perchlorate wastewater, including the matrix of crustacean biomass with porous structure, the surface of the matrix of crustacean biomass and the pore structure are loaded with modified material, the modified material is mainly prepared by mixing reaction of aluminum source, iron source, solid base, excitation agent.The application also provides a kind of preparation method of the above-mentioned efficient targeted adsorbent and its application.The efficient targeted adsorbent for treating perchlorate wastewater and its preparation method of the application, by modifying adsorption material, the surface and internal void surface characteristics are optimized, so that the whole adsorption material is positively charged, so that it becomes the carrier of adsorbing perchlorate in water body, and the adsorption capacity and adsorption selectivity are improved.

Description

Technical Field

[0001] This invention belongs to the field of wastewater treatment, and particularly relates to an adsorbent, its preparation method, and its application. Background Technology

[0002] Perchlorate is a novel persistent pollutant, primarily generated in industries such as military, fireworks, firecrackers, textile printing and dyeing, electroplating, rubber, and paint. Perchlorate has a tetrahedral structure and is characterized by its small molecular weight, high solubility, rapid diffusion, long residual time, extreme stability in water, non-volatile nature, and extreme difficulty in activation by oxidants.

[0003] Currently, research on perchlorate removal mainly focuses on ion exchange, adsorption, membrane filtration, microbial methods, and chemical reduction. Among these, ion exchange technology is still immature, and the regeneration of waste resin and the treatment and disposal of concentrated brine are difficult; membrane filtration has high investment and operating costs, and complex and demanding operating conditions, making industrial application difficult; microbial methods face challenges in screening reducing bacteria, wastewater treatment is time-consuming, and treatment effects are unstable; chemical reduction requires high reaction activation energy, such as ClO4. - Although chlorine has a tetrahedral structure and is in the +7 oxidation state, its oxidizing properties are extremely difficult to activate, requiring a catalyst to promote the reaction process. The catalytic reduction reaction conditions are quite demanding, the catalyst preparation cost is high, and there is a risk of secondary pollution. Compared to the above methods, adsorption has advantages such as mature technology and low cost. However, for high-concentration perchlorate wastewater (perchlorate content > 500 mg / L), the adsorbents used in traditional adsorption methods have small adsorption capacity and low adsorption reaction efficiency. Furthermore, the adsorbents used in traditional adsorption methods lack specificity, and the adsorption process is easily interfered with by other ions, thus failing to meet the requirements for treating high-concentration perchlorate wastewater. Summary of the Invention

[0004] The technical problem to be solved by this invention is to overcome the shortcomings and defects mentioned in the background art above, and to provide a highly efficient targeted adsorbent for treating perchlorate wastewater with large adsorption capacity, high adsorption efficiency, and good adsorption specificity, as well as its preparation method and applications. To solve the above technical problem, the technical solution proposed by this invention is as follows:

[0005] A highly efficient targeted adsorbent for treating perchlorate wastewater includes a crustacean biomass matrix with a porous structure. The surface and pore structure of the crustacean biomass matrix are loaded with a modified material, which is mainly prepared by mixing and reacting an aluminum source, an iron source, a solid alkali, and an activator.

[0006] In the aforementioned highly efficient targeted adsorbents, preferably, the aluminum source includes aluminum sulfate and / or aluminum chloride, the iron source includes ferric sulfate and / or ferric chloride, the solid alkali includes one or more of solid sodium hydroxide, solid calcium hydroxide, and solid potassium hydroxide, and the activator includes one or more of DL-methionine methylsulfonium chloride, cystamine sulfate, triphenylsulfonium hexafluorophosphate, and trimethyltetrafluoroborate sulfonium. The reaction of the aluminum source, iron source, solid alkali, and activator generates a gelling material, altering the surface properties and structure of the crustacean biomass, forming specific functional groups on the crustacean biomass, and creating a porous, multifunctional structure, further improving the adsorption capacity, adsorption selectivity, and stability of the adsorbent.

[0007] As a general technical concept, the present invention also provides a method for preparing the above-mentioned highly efficient targeted adsorbent, comprising the following steps:

[0008] (1) The shell biomass is washed, roasted, crushed, and then acid-treated to obtain pretreated shell biomass.

[0009] (2) The pretreated crustacean biomass obtained in step (1) is mixed with aluminum source, iron source, solid alkali and activator to form a paste, and then cured to obtain a cured paste.

[0010] (3) The aging paste obtained in step (2) is washed, dried and pulverized to obtain the highly efficient targeted adsorbent.

[0011] In the above preparation method, preferably, the acid treatment includes the following steps: slowly adding the crushed shell biomass into an acid solution while stirring to obtain a slurry mixture, and then placing the slurry mixture in a closed pressure reactor for a constant temperature and pressure hydrothermal reaction.

[0012] In the above preparation method, preferably, the acid solution includes one or more of citric acid, oxalic acid, and tartaric acid, with a concentration ≤0.02 mol / L. The stirring intensity is controlled at 80-120 r / min, the pH value of the slurry mixture is 5.5-6.5, the pressure of the isothermal hydrothermal reaction is 1.0-1.5 MPa, the temperature is 120-150℃, and the time is 3-5 h. This invention incorporates a low-concentration acid treatment to slowly erode the material without damaging its overall structure. Simultaneously, the isothermal hydrothermal reaction under the above process conditions improves the pore structure, ensuring that the pore structure is subjected to relatively uniform high pressure and high temperature during formation, resulting in rapid pore formation and relatively uniform pores.

[0013] In the above preparation method, preferably, the mass ratio of the pretreated crustacean biomass, aluminum source, iron source, solid alkali, and activator is 100:(5-10):(6-12):(2-5):(1.5-2.5). The amounts of the pretreated crustacean biomass, aluminum source, iron source, solid alkali, and activator need to be reasonably controlled so that the main material, the crustacean biomass carrier, combines with a certain amount of aluminum and iron sources, and under the activation effect of a small amount of solid alkali and activator, forms the corresponding adsorbent precursor.

[0014] In the above preparation method, preferably, the moisture content of the paste is controlled at 45%-65% (mass moisture content) during the curing process, the curing time is 36-48 hours, and the process is carried out at room temperature and pressure.

[0015] In the above preparation method, preferably, the washing, roasting, and pulverizing of the shellfish biomass involves first washing the shellfish biomass with water to remove attached impurities, then roasting it, and finally pulverizing the shellfish biomass to 20-60 mesh. The roasting temperature is controlled at 150-200℃ for 1-2 hours. The shellfish biomass is marine shellfish biomass, including natural conch shells, scallop shells, blue shells, and colorful shells. The roasting treatment primarily aims to rapidly evaporate the water of crystallization within the washed material, stabilize the surface structure and functional groups, and cause lattice distortion to create voids, thereby increasing the specific surface area.

[0016] In the above preparation method, preferably, the aging paste obtained in step (3) is washed, dried and crushed. First, the aging paste is washed with water, then dried and crushed to 80-120 mesh. When washing with water, the liquid-solid ratio is controlled at (2-3):1 and washed 3-5 times. When drying, the drying temperature is 80-100℃.

[0017] As a general technical concept, this invention also provides the application of the above-mentioned highly efficient targeted adsorbent for treating perchlorate wastewater in the adsorption of perchlorate wastewater. In specific use, the highly efficient targeted adsorbent is added to the perchlorate wastewater at a certain dosage, controlling the pH value of the perchlorate wastewater to be 2.5-12.0, the total salinity to ≤6%, the stirring intensity to be 60-120 r / min, the reaction time to be 5-30 min, and solid-liquid separation to occur. The perchlorate wastewater can be taken from the supernatant of a fireworks factory sedimentation tank, with a perchlorate concentration of 500-2000 mg / L; the main salt components are sodium chloride, sodium sulfate, potassium chloride, potassium sulfate, etc.; the mass ratio of the highly efficient targeted adsorbent to the perchlorate wastewater is (1-4):1000.

[0018] This invention first utilizes acid to erode the surface of crustacean biomass under high-pressure hydrothermal conditions, forming a porous structure, optimizing the pore structure, increasing the specific surface area, and improving adsorption capacity. Simultaneously, aluminum and iron sources are introduced into the crustacean biomass to form an activated system. The aluminum and iron sources are thoroughly mixed with the crustacean biomass, and under the activation of the active component (solid alkali) and activator, a gelling material is produced, altering its surface properties and structure. Specific functional groups are formed on the material, creating a porous, multi-functional structure that further improves adsorption capacity, selectivity, and stability. Specifically, the crustacean biomass, through treatment, forms a porous structure with a large specific surface area, enhancing adsorption capacity. The addition of aluminum, iron, solid alkali, and activator introduces functional groups such as iron-aluminum hydroxyl compounds (e.g., Al-OH, α-FeOOH, and β-FeOOH), sulfides, and hydroxyl groups, and generates other complex functional groups on the surface, stably loading them on the surface and pore surfaces, increasing affinity for pollutants, and further improving adsorption. Simultaneously, the OH2 in the crustacean biomass molecular structure... + Positively charged, it readily combines electrostatically with perchlorate ions. Furthermore, the introduction of thioether and hydroxyl functional groups onto the material, with the thioether groups readily protonated to form cations, results in a high positive charge density on the adsorbent surface. This allows for strong adsorption of negatively charged perchlorate ions. Through various influencing factors, the affinity between the adsorbent and perchlorate ions is enhanced, giving it adsorption specificity and allowing for highly selective adsorption of perchlorate ions from wastewater (compared to other anions, it is more easily adsorbed by the adsorbent of this invention). In addition, after acidification and aging steps, the surface structure of the adsorbent material becomes stable, its impact resistance is enhanced, and the loaded functional groups are also very stable. It has a wide applicability range for wastewater pH and high stability.

[0019] The highly efficient targeted adsorbent of this invention reacts with an aluminum source, an iron source, a solid alkali, and an activator to produce a gelling substance. This substance does not significantly clog the pores of crustacean biomass but alters its surface properties and structure, forming specific functional groups on the material to improve its performance. This highly efficient targeted adsorbent requires loading the aforementioned gelling substance onto the surface of the crustacean biomass. Through the combined action of the characteristics of the crustacean biomass and the gelling substance produced by the reaction of the aluminum source, iron source, solid alkali, and activator, a highly efficient targeted adsorbent with high adsorption capacity, selectivity, and stability can be obtained.

[0020] This invention first utilizes acid to erode the surface of crustacean biomass under high-pressure hydrothermal conditions, forming a porous structure. Then, through aging treatment and linking of functional groups, its high-efficiency adsorption capacity is activated, thus completing the preparation of a highly efficient targeted adsorbent for perchlorate. This highly efficient targeted adsorbent for perchlorate has a porous and complex structure with a large specific surface area and a large adsorption capacity, reaching 500 mg / g. It reaches adsorption saturation within 5-20 minutes, overcoming the limitations of traditional perchlorate adsorbents with small adsorption capacity and slow reaction rates, which cannot meet the treatment requirements of high-concentration perchlorate wastewater. Simultaneously, the adsorption exhibits relative specificity, enabling efficient and rapid treatment of high-concentration perchlorate wastewater and selective removal of perchlorate in high-salt systems. Furthermore, this highly efficient targeted adsorbent is applicable to a wide range of wastewater pH, uses readily available and inexpensive raw materials, and the entire preparation process requires simple equipment, allowing for large-scale production and possessing high potential for widespread application. Overall, the highly efficient targeted adsorbent of this invention has a high removal effect on perchlorate ions, stable treatment effect, short reaction time, and significantly improves treatment capacity and efficiency, which is conducive to the recycling of wastewater and has good economic and environmental benefits.

[0021] Compared with the prior art, the advantages of the present invention are as follows:

[0022] 1. The present invention relates to a highly efficient targeted adsorbent for treating perchlorate wastewater and its preparation method. By modifying the adsorbent material, the surface characteristics of the surface and internal pores are optimized, making the adsorbent material positively charged as a whole, thus turning it into a carrier for adsorbing perchlorate in water, thereby improving the adsorption capacity and adsorption selectivity.

[0023] 2. The highly efficient targeted adsorbent for treating perchlorate wastewater of the present invention has a wide applicable pH range for wastewater, readily available and inexpensive raw materials, simple equipment for the entire preparation process, and can be mass-produced, making it highly valuable for promotion. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a SEM image of the highly efficient targeted adsorbent for treating perchlorate wastewater prepared in Example 3. Detailed Implementation

[0026] To facilitate understanding of the present invention, the present invention will be described more fully and in detail below with reference to the accompanying drawings and preferred embodiments, but the scope of protection of the present invention is not limited to the following specific embodiments.

[0027] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by those skilled in the art. The technical terms used herein are for the purpose of describing particular embodiments only and are not intended to limit the scope of the invention.

[0028] Unless otherwise specified, all raw materials, reagents, instruments and equipment used in this invention can be purchased from the market or prepared by existing methods.

[0029] Example 1:

[0030] A highly efficient targeted adsorbent for treating perchlorate wastewater includes a shell biomass matrix with a porous structure, wherein the surface and pore structure of the shell biomass matrix are loaded with a modified material, which is mainly prepared by mixing and reacting an aluminum source, an iron source, a solid alkali, and an activator.

[0031] The preparation method of the above-mentioned highly efficient targeted adsorbent for treating perchlorate wastewater includes the following steps:

[0032] (1) Wash the shell biomass with water to remove the attached impurities, and then roast it. The shell biomass is a seashell. The roasting temperature is 150℃ and the roasting time is 1h.

[0033] (2) Crush the crustacean biomass from step (1) to 20 mesh.

[0034] (3) Slowly add a dilute acid solution to the crustacean biomass in step (2) while stirring to obtain a slurry mixture. Adjust the pH value to 6.5. The acid solution is citric acid with a concentration of 0.02 mol / L and the stirring intensity is 80 r / min.

[0035] (4) Place the slurry mixture from step (3) into a closed pressure reactor and carry out a hydrothermal reaction at a pressure of 1.0 MPa and a temperature of 120°C for 3 hours under constant temperature and pressure.

[0036] (5) After the crustacean biomass from step (4) has cooled naturally, add ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to the reactor and mix thoroughly. Stir to form a paste, maintain a moisture content of 50%, and mature for 36 hours. Control the mass ratio of crustacean biomass, ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to be 100:5:6:2:1.5.

[0037] (6) Add water to the paste-like substance after maturation in step (5) and wash it. The liquid-to-solid ratio is 2:1 each time, and the washing is repeated 3 times.

[0038] (7) The paste-like substance washed in step (6) is dried at 85°C and then crushed to 80 mesh to obtain the high-efficiency targeted adsorbent for treating perchlorate wastewater in this embodiment.

[0039] The highly efficient targeted adsorbent prepared in this embodiment was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratio of the highly efficient targeted adsorbent to the perchlorate wastewater was 1:1000, 2:1000, 3:1000, and 4:1000, respectively. The treatment results are shown in Table 1 below.

[0040] Table 1: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0041] Different mass ratio treatment <![CDATA[ClO4 - Concentration (mg / L) <![CDATA[ClO4 - Removal rate (%) raw water 776.25 / 1：1000 583.28 25.86 2：1000 395.42 49.06 3：1000 194.63 74.92 4：1000 ＜0.004 100

[0042] As shown in Table 1, the perchlorate adsorbent prepared by treating crustacean biomass using the method described in this embodiment exhibits excellent removal efficiency for perchlorate in wastewater. With increasing adsorbent dosage, the perchlorate removal rate gradually increases. When the adsorbent-to-wastewater mass ratio is 4:1000, the perchlorate removal rate reaches 100%, with an adsorption capacity of approximately 0.2 g / g, effectively achieving the removal of perchlorate from the wastewater.

[0043] Example 2:

[0044] A highly efficient targeted adsorbent for treating perchlorate wastewater includes a shell biomass matrix with a porous structure, wherein the surface and pore structure of the shell biomass matrix are loaded with a modified material, which is mainly prepared by mixing and reacting an aluminum source, an iron source, a solid alkali, and an activator.

[0045] The preparation method of the above-mentioned highly efficient targeted adsorbent for treating perchlorate wastewater includes the following steps:

[0046] (1) Wash the shell biomass with water to remove the attached impurities, and then roast it. The shell biomass is a seashell. The roasting temperature is 180℃ and the roasting time is 1.5h.

[0047] (2) Crush the crustacean biomass from step (1) to 40 mesh.

[0048] (3) Slowly add a dilute acid solution to the crustacean biomass in step (2) while stirring to obtain a slurry mixture. Adjust the pH value to 6.0. The acid solution is citric acid with a concentration of 0.02 mol / L and the stirring intensity is 80 r / min.

[0049] (4) Place the slurry mixture from step (3) into a closed pressure reactor and carry out a hydrothermal reaction at a pressure of 1.25 MPa and a temperature of 130°C for 4 hours under constant temperature and pressure.

[0050] (5) After the crustacean biomass from step (4) has cooled naturally, add ferric chloride, aluminum chloride, solid calcium hydroxide, and DL-methionine methyl sulfonium chloride to the reactor and mix thoroughly. Stir to form a paste, maintain a moisture content of 50%, and mature for 48 hours. Control the mass ratio of crustacean biomass, ferric chloride, aluminum chloride, solid calcium hydroxide, and DL-methionine methyl sulfonium chloride to be 100:6:6:2.5:2.

[0051] (6) Add water to the paste-like substance after maturation in step (5) and wash it. The liquid-to-solid ratio is 3:1 each time, and the washing is repeated 5 times.

[0052] (7) The paste-like substance washed in step (6) is dried at 80°C and then crushed to 120 mesh to obtain the high-efficiency targeted adsorbent for treating perchlorate wastewater in this embodiment.

[0053] The highly efficient targeted adsorbent prepared in this embodiment was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratio of the highly efficient targeted adsorbent to the perchlorate wastewater was 1:1000, 1.5:1000, 1.8:1000, and 2:1000, respectively. The treatment results are shown in Table 2 below.

[0054] Table 2: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0055]

[0056]

[0057] As shown in Table 2, the perchlorate adsorbent prepared by treating crustacean biomass using the method described in this embodiment exhibits excellent removal efficiency for perchlorate in wastewater. With increasing adsorbent dosage, the perchlorate removal rate gradually increases. When the adsorbent-to-wastewater mass ratio is 2:1000, the perchlorate removal rate reaches 100%, with an adsorption capacity of approximately 0.42 g / g, effectively achieving the removal of perchlorate from the wastewater.

[0058] Example 3:

[0059] A highly efficient targeted adsorbent for treating perchlorate wastewater includes a shell biomass matrix with a porous structure, wherein the surface and pore structure of the shell biomass matrix are loaded with a modified material, which is mainly prepared by mixing and reacting an aluminum source, an iron source, a solid alkali, and an activator.

[0060] The preparation method of the above-mentioned highly efficient targeted adsorbent for treating perchlorate wastewater includes the following steps:

[0061] (1) Wash the shell biomass with water to remove the attached impurities, and then roast it. The shell biomass is a seashell. The roasting temperature is 200℃ and the roasting time is 2h.

[0062] (2) Crush the crustacean biomass from step (1) to 60 mesh.

[0063] (3) Slowly add a dilute acid solution to the crustacean biomass in step (2) while stirring to obtain a slurry mixture. Adjust the pH value to 5.5. The acid solution is citric acid with a concentration of 0.01 mol / L and the stirring intensity is 80 r / min.

[0064] (4) Place the slurry mixture from step (3) into a closed pressure reactor and carry out a hydrothermal reaction at a pressure of 1.5 MPa and a temperature of 150°C for 5 hours under constant temperature and pressure.

[0065] (5) After the crustacean biomass from step (4) has cooled naturally, add ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to the reactor and mix thoroughly. Stir to form a paste, maintain a moisture content of 50%, and mature for 48 hours. Control the mass ratio of crustacean biomass, ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to be 100:8:10:4:2.5.

[0066] (6) Add water to the paste-like substance after maturation in step (5) and wash it. The liquid-to-solid ratio is 3:1 each time, and the washing is repeated 5 times.

[0067] (7) The paste-like substance washed in step (6) is dried at 85°C and then crushed to 120 mesh to obtain the high-efficiency targeted adsorbent for treating perchlorate wastewater in this embodiment.

[0068] The SEM image of the highly efficient targeted adsorbent prepared in this embodiment is shown below. Figure 1 As shown in the figure, the preparation method of this embodiment can yield an adsorbent material with a uniform porous structure.

[0069] The preparation conditions in this embodiment are more stringent, with lower acidity during acidification and higher temperature and pressure during hydrothermal reaction, which is conducive to preparing adsorbent materials with better performance.

[0070] The highly efficient targeted adsorbent prepared in this embodiment was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratios of the highly efficient targeted adsorbent to the perchlorate wastewater were 1:1000, 1.2:1000, 1.4:1000, and 1.6:1000, respectively. The treatment results are shown in Table 3 below.

[0071] Table 3: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0072] Different mass ratio treatment <![CDATA[ClO4 - Concentration (mg / L) <![CDATA[ClO4 - Removal rate (%) raw water 776.25 / 1：1000 264.53 65.92 1.2：1000 163.25 78.97 1.4：1000 58.96 92.40 1.6：1000 ＜0.004 100

[0073] As shown in Table 3, the perchlorate adsorbent prepared by treating crustacean biomass using the method described in this embodiment exhibits excellent removal efficiency for perchlorate in wastewater. With increasing adsorbent dosage, the perchlorate removal rate gradually increases. When the adsorbent-to-wastewater mass ratio is 1.6:1000, the perchlorate removal rate reaches 100%, with an adsorption capacity of approximately 0.5 g / g, effectively achieving the removal of perchlorate from the wastewater.

[0074] When the highly efficient targeted adsorbent prepared in this embodiment was added to perchlorate wastewater at a certain dosage, the pH value of the perchlorate wastewater was changed, and experiments were conducted as follows: the pH value of the perchlorate wastewater was adjusted to 2.5, 4.0, 6.0, 7.5, 9.0, 10.5, and 12.0, the total salinity was 0.25%, the main salt component was sodium sulfate, the stirring intensity was 80 r / min, the reaction time was 15 min, and solid-liquid separation was performed. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, and the perchlorate concentration was 776.25 mg / L; the mass ratio of the highly efficient targeted adsorbent to the perchlorate wastewater was 1.6:1000, and the treatment results are shown in Table 4 below.

[0075] Table 4: ClO4 in wastewater under different pH conditions - Removal effect result table

[0076] Different pH <![CDATA[ClO4 - Concentration (mg / L) <![CDATA[ClO4 - Removal rate (%) 2.5 103.68 86.64 4.0 39.56 94.90 6.0 10.36 98.67 7.5 (raw water) ＜0.004 100 9.0 8.27 98.93 10.5 29.12 96.25 12.0 86.31 88.88

[0077] As shown in Table 4, the perchlorate adsorbent prepared by treating crustacean biomass using the method of this embodiment has a good removal effect on perchlorate in wastewater and a wide applicable pH range for wastewater. The optimal wastewater pH is neutral. Under strong acidic and alkaline conditions of pH 3.0 and 12.0, the perchlorate removal rate can still reach more than 86%, effectively achieving the removal of perchlorate from wastewater.

[0078] When the highly efficient targeted adsorbent prepared in this embodiment was added to perchlorate wastewater at a certain dosage, the total salinity of the perchlorate wastewater was changed, and experiments were conducted as follows: the pH of the perchlorate wastewater was controlled at 7.5, and the total salinity was adjusted to 0.25%, 1%, 2%, 3%, 4%, 5%, and 6%, respectively. The main salt component was sodium sulfate. The stirring intensity was 80 r / min, the reaction time was 15 min, and solid-liquid separation was performed. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, and the perchlorate concentration was 776.25 mg / L. The mass ratio of the highly efficient targeted adsorbent to the perchlorate wastewater was 1.6:1000. The treatment results are shown in Table 5 below.

[0079] Table 5: ClO4 in wastewater under different total salinity conditions - Removal effect result table

[0080] Different total salinity (%) <![CDATA[ClO4 - Concentration (mg / L) <![CDATA[ClO4 - Removal rate (%) 0.25 (raw water) ＜0.004 100 1 ＜0.004 100 2 ＜0.004 100 3 ＜0.004 100 4 ＜0.004 100 5 10.28 98.67 6 27.25 96.49

[0081] As shown in Table 5, the perchlorate adsorbent prepared by treating crustacean biomass using the method of this embodiment has a good removal effect on perchlorate in wastewater and a wide range of applicability to the total salinity of the wastewater. The optimal total salinity of the wastewater is <5. In a high-salt system with a total salinity of 6%, the removal rate of perchlorate can still reach 96.49%, indicating that the adsorbent has strong specificity for the adsorption of perchlorate ions and can basically eliminate the influence of other ions in high-salt wastewater on the adsorption process, effectively achieving the removal of perchlorate from high-salt wastewater.

[0082] Example 4:

[0083] A highly efficient targeted adsorbent for treating perchlorate wastewater includes a shell biomass matrix with a porous structure, wherein the surface and pore structure of the shell biomass matrix are loaded with a modified material, which is mainly prepared by mixing and reacting an aluminum source, an iron source, a solid alkali, and an activator.

[0084] The preparation method of the above-mentioned highly efficient targeted adsorbent for treating perchlorate wastewater includes the following steps:

[0085] (1) Wash the shell biomass with water to remove the attached impurities, and then roast it. The shell biomass is a seashell. The roasting temperature is 200℃ and the roasting time is 2h.

[0086] (2) Crush the crustacean biomass from step (1) to 60 mesh.

[0087] (3) Slowly add a dilute acid solution to the crustacean biomass in step (2) while stirring to obtain a slurry mixture. Adjust the pH value to 5.5. The acid solution is oxalic acid with a concentration of 0.01 mol / L and the stirring intensity is 80 r / min.

[0088] (4) Place the slurry mixture from step (3) into a closed pressure reactor and carry out a hydrothermal reaction at a pressure of 1.5 MPa and a temperature of 150°C for 5 hours under constant temperature and pressure.

[0089] (5) After the crustacean biomass from step (4) has cooled naturally, add ferric sulfate, aluminum sulfate, solid potassium hydroxide, and triphenylsulfonium hexafluorophosphate to the reactor and mix thoroughly. Stir to form a paste, maintain a moisture content of 50%, and mature for 48 hours. Control the mass ratio of crustacean biomass, ferric sulfate, aluminum sulfate, solid potassium hydroxide, and triphenylsulfonium hexafluorophosphate to be 100:8:10:4:2.5.

[0090] (6) Add water to the paste-like substance after maturation in step (5) and wash it. The liquid-to-solid ratio is 3:1 each time, and the washing is repeated 5 times.

[0091] (7) The paste-like substance washed in step (6) is dried at 85°C and then crushed to 120 mesh to obtain the high-efficiency targeted adsorbent for treating perchlorate wastewater in this embodiment.

[0092] The highly efficient targeted adsorbent prepared in this embodiment was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratios of the highly efficient targeted adsorbent to the perchlorate wastewater were 1:1000, 1.2:1000, 1.4:1000, and 1.6:1000, respectively. The treatment results are shown in Table 6 below.

[0093] Table 6: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0094] Different mass ratio treatment <![CDATA[ClO4 - Concentration (mg / L) <![CDATA[ClO4 - Removal rate (%) raw water 776.25 / 1：1000 248.57 67.98 1.2：1000 173.15 77.69 1.4：1000 48.16 93.79 1.6：1000 ＜0.004 100

[0095] As shown in Table 6, the perchlorate adsorbent prepared by treating crustacean biomass using the method described in this embodiment exhibits excellent removal efficiency for perchlorate in wastewater. With increasing adsorbent dosage, the perchlorate removal rate gradually increases. When the adsorbent-to-wastewater mass ratio is 1.6:1000, the perchlorate removal rate reaches 100%, with an adsorption capacity of approximately 0.5 g / g, effectively achieving the removal of perchlorate from the wastewater.

[0096] Comparative Example 1:

[0097] A method for preparing an adsorbent includes the following steps:

[0098] (1) Wash the shell biomass with water to remove the attached impurities, and then roast it. The shell biomass is a seashell. The roasting temperature is 150℃ and the roasting time is 1h.

[0099] (2) The crustacean biomass from step (1) is crushed to 60 mesh to obtain an adsorbent.

[0100] The powdered chitinous biomass adsorbent obtained in step (2) was added to the perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, and the perchlorate concentration was 776.25 mg / L. The mass ratio of adsorbent to perchlorate wastewater was 1:1000, 2:1000, 3:1000, and 4:1000. The treatment results are shown in Table 7 below.

[0101] Table 7: ClO4 in wastewater under different amounts of crustacean biomass addition - Removal effect result table

[0102] Different mass ratio treatment <![CDATA[ClO4 - Concentration (mg / L) raw water 776.25 1：1000 776.37 2：1000 775.96 3：1000 769.38 4：1000 776.82

[0103] As shown in Table 7, roasting and pulverizing the crustacean biomass and then directly adding it to perchlorate wastewater reduces the ClO4 content in the wastewater. - The removal of ClO4 has almost no effect; crustacean biomass not treated by the preparation process of this invention has no effect on the removal of ClO4. - It does not have an adsorption effect.

[0104] Comparative Example 2:

[0105] A method for preparing an adsorbent includes the following steps:

[0106] (1) Wash the crustacean biomass with water to remove the attached impurities, and then roast it. The crustacean biomass is mainly shells. The roasting temperature is 200℃ and the roasting time is 2h.

[0107] (2) Crush the crustacean biomass from step (1) to 60 mesh.

[0108] (3) Slowly add a dilute acid solution to the crustacean biomass in step (2) while stirring to obtain a slurry mixture. Adjust the pH value to 5.5. The acid solution is citric acid with a concentration of 0.01 mol / L and the stirring intensity is 80 r / min.

[0109] (4) Place the slurry mixture from step (3) into a closed pressure reactor and carry out a hydrothermal reaction at a pressure of 1.5 MPa and a temperature of 150°C for 5 hours under constant temperature and pressure.

[0110] (5) The substance after hydrothermal reaction in step (4) is dried at 85°C and then crushed to 120 mesh to obtain the adsorbent.

[0111] The adsorbent prepared in this comparative example was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratios of the high-efficiency targeted adsorbent to the perchlorate wastewater were 1:1000, 2:1000, 3:1000, and 4:1000, respectively. The treatment results are shown in Table 8 below.

[0112] Table 8: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0113]

[0114]

[0115] As shown in Table 8, the results indicate that directly adding the roasted, crushed, acidified, and hydrothermal-treated crustacean biomass to perchlorate wastewater effectively reduces the ClO4 content in the wastewater. - While there is some effect on the removal of ClO4, the effect is very small. When the mass ratio of adsorbent to wastewater is 4:1000, the removal rate of perchlorate in the wastewater is only 3.52%. Without the complete preparation process of this invention, the removal rate of ClO4 from the crustacean biomass is significantly lower. - The adsorption effect is not very good.

[0116] Comparative Example 3:

[0117] A method for preparing an adsorbent includes the following steps:

[0118] (1) Add ferric chloride, aluminum chloride, solid calcium hydroxide, DL-methionine methyl sulfonium chloride and an appropriate amount of water to the reaction vessel and mix thoroughly. Stir to form a paste, maintain a moisture content of 50%, and mature for 48 hours. Control the mass ratio of ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to be 6:6:2.5:2.

[0119] (2) Add water to the paste-like substance after maturation in step (1) and wash it. The liquid-to-solid ratio is 3:1 each time, and the washing is repeated 5 times.

[0120] (3) The paste-like substance washed in step (2) is dried at 80°C and then crushed to 120 mesh to obtain the adsorbent.

[0121] The adsorbent prepared in this comparative example was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratio of adsorbent to perchlorate wastewater was 1:1000, 2:1000, 3:1000, and 4:1000, respectively. The treatment results are shown in Table 9 below.

[0122] Table 9: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0123] Different mass ratio treatment <![CDATA[ClO4 - Concentration (mg / L) raw water 776.25 1：1000 774.15 2：1000 769.65 3：1000 778.54 4：1000 775.36

[0124] As shown in Table 9, the adsorbents prepared directly using aluminum source, iron source, solid alkali and activator effectively target ClO4 in wastewater. - It has almost no effect on the removal of ClO4. - It does not have an adsorption effect.

[0125] Comparative Example 4:

[0126] A method for preparing an adsorbent includes the following steps:

[0127] (1) Wash the activated carbon with water to remove the attached impurities, and then calcine it at a temperature of 200℃ for 2 hours.

[0128] (2) Crush the activated carbon from step (1) to 60 mesh.

[0129] (3) Slowly add dilute acid solution to the activated carbon in step (2) while stirring to obtain a slurry mixture. Adjust its pH value to 5.5. The acid solution is citric acid with a concentration of 0.01 mol / L and the stirring intensity is 80 r / min.

[0130] (4) Place the slurry mixture from step (3) into a closed pressure reactor and carry out a hydrothermal reaction at a pressure of 1.5 MPa and a temperature of 150°C for 5 hours under constant temperature and pressure.

[0131] (5) After the activated carbon from step (4) has cooled naturally, add ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to the reaction vessel and mix thoroughly. Stir to form a paste, maintain a moisture content of 50%, and mature for 48 hours. Control the mass ratio of activated carbon, ferric chloride, aluminum chloride, solid calcium hydroxide and DL-methionine methyl sulfonium chloride to be 100:8:10:4:2.5.

[0132] (6) Add water to the paste-like substance after maturation in step (5) and wash it. The liquid-to-solid ratio is 3:1 each time, and the washing is repeated 5 times.

[0133] (7) The paste-like substance washed in step (6) is dried at 85°C and then crushed to 120 mesh to obtain the adsorbent of this embodiment.

[0134] The adsorbent prepared in this comparative example was added to perchlorate wastewater at a certain dosage. The pH of the perchlorate wastewater was controlled at 7.5, the total salinity at 0.25%, and the main salt component was sodium sulfate. The stirring intensity was 80 r / min, and the reaction was carried out for 15 min, followed by solid-liquid separation. The perchlorate wastewater was taken from the supernatant of the sedimentation tank of a fireworks factory, with a perchlorate concentration of 776.25 mg / L. The mass ratio of adsorbent to perchlorate wastewater was 1:1000, 2:1000, 3:1000, and 4:1000, respectively. The treatment results are shown in Table 10 below.

[0135] Table 10: ClO4 in wastewater under different adsorbent dosages - Removal effect result table

[0136] Different mass ratio treatment <![CDATA[ClO4 - Concentration (mg / L) raw water 776.25 1：1000 765.12 2：1000 751.23 3：1000 766.89 4：1000 764.88

[0137] As shown in Table 10, the adsorbent material made by using activated carbon instead of crustacean biomass has a very poor effect on the removal of perchlorate in wastewater and cannot achieve the removal of perchlorate in wastewater.

Claims

1. A highly efficient targeted adsorbent for treating perchlorate wastewater, characterized in that, The invention includes a crustacean biomass matrix with a porous structure, wherein the surface and pore structure of the crustacean biomass matrix are loaded with a modified material, which is mainly prepared by mixing and reacting an aluminum source, an iron source, a solid alkali, and an activator; the activator includes one or more of DL-methionine methyl sulfonium chloride, cystamine sulfate, triphenyl sulfonium hexafluorophosphate, and trimethyltetrafluoroborate sulfonium. The preparation method of the highly efficient targeted adsorbent includes the following steps: (1) The shell biomass is washed, roasted, crushed, and then acid-treated to obtain pretreated shell biomass; (2) The pretreated crustacean biomass obtained in step (1) is mixed with aluminum source, iron source, solid alkali and activator to form a paste, and then cured to obtain a cured paste; (3) The aging paste obtained in step (2) is washed, dried and pulverized to obtain the highly efficient targeted adsorbent; The acid treatment includes the following steps: slowly adding the crushed crustacean biomass into an acid solution while stirring to obtain a slurry mixture, and then placing the slurry mixture in a closed pressure reactor for a constant temperature and pressure hydrothermal reaction.

2. The highly efficient targeted adsorbent according to claim 1, characterized in that, The aluminum source includes aluminum sulfate and / or aluminum chloride, the iron source includes ferric sulfate and / or ferric chloride, and the solid alkali includes one or more of solid sodium hydroxide, solid calcium hydroxide, and solid potassium hydroxide.

3. The highly efficient targeted adsorbent according to claim 1, characterized in that, The acid solution includes one or more of citric acid, oxalic acid, and tartaric acid, with a concentration ≤0.02mol / L. The stirring intensity is controlled at 80-120r / min, the pH value of the slurry mixture is 5.5-6.5, the pressure of the constant temperature and pressure hydrothermal reaction is 1.0-1.5MPa, the temperature is 120-150℃, and the time is 3-5h.

4. The highly efficient targeted adsorbent according to claim 1, characterized in that, The mass ratio of the pretreated crustacean biomass, aluminum source, iron source, solid alkali and activator is 100:(5-10):(6-12):(2-5):(1.5-2.5).

5. The highly efficient targeted adsorbent according to claim 1, characterized in that, During the curing process, the moisture content of the paste should be controlled at 45-65%, and the curing time should be 36-48 hours.

6. The highly efficient targeted adsorbent according to any one of claims 1-5, characterized in that, The process of washing, roasting, and pulverizing crustacean biomass involves first washing the crustacean biomass with water to remove attached impurities, then roasting it, and finally pulverizing it to 20-60 mesh. The roasting temperature is controlled at 150-200℃ for 1-2 hours. The crustacean biomass is marine shellfish biomass.

7. The highly efficient targeted adsorbent according to any one of claims 1-5, characterized in that, The aging paste obtained in step (2) is washed, dried and crushed. First, the aging paste is washed with water, then dried and crushed to 80-120 mesh. When washing with water, the liquid-solid ratio is controlled at (2-3):1 and washed 3-5 times. When drying, the drying temperature is 80-100℃.

8. The application of any one of the high-efficiency targeted adsorbents according to claims 1-7 in the adsorption of perchlorate wastewater.

Images