An adsorbent material for treating wastewater and a method of making the same

Abstract

The application discloses an adsorbent material for treating wastewater and a preparation method thereof, and comprises the following steps: S1, preparation of porous biochar; S2, pretreatment of the porous biochar; S3, preparation of modified porous biochar; S4, preparation of modified sepiolite; and S5, preparation of the adsorbent material. The adsorbent material is prepared by combining the modified porous biochar with the modified sepiolite, so that the respective advantages of the two are exerted, and hydroxypropyl-beta-cyclodextrin is introduced, so that the heavy metal ions and organic pollutants in the chemical wastewater can be adsorbed through the synergistic effect of the three, and the adsorbent material can be separated through filtration after adsorption is completed, so that the operability of the adsorbent material is greatly improved, and the method is simple and easy to implement, and no secondary pollution is caused.

Description

Technical Field

[0001] This invention belongs to the field of chemical wastewater adsorbent technology, specifically relating to an adsorbent material for treating wastewater and its preparation method. Background Technology

[0002] The petrochemical industry plays a vital role in modern society; however, its massive production also generates large amounts of wastewater containing various organic compounds, heavy metals, and other harmful substances, posing a serious threat to the environment and ecosystems. In recent years, with increasing environmental awareness and increasingly stringent environmental regulations, the research and practice of petrochemical wastewater treatment technologies have become particularly important. The treatment of petrochemical wastewater involves complex chemical, biological, and physical processes, characterized by the complex and diverse composition of the wastewater, high pollutant concentrations, and significant harm to the ecological environment.

[0003] The basic characteristics of chemical wastewater are: (1) The wastewater has a complex composition, especially with many byproducts after mixing. Because chemical reaction processes often use solvents and organic compounds with more cyclic molecular structures, it is more difficult to treat than domestic sewage. (2) The wastewater has a high concentration of pollutants, which is caused by the incomplete reaction of raw materials and the large amount of solvent media that must be used due to the reaction conditions. These pollutants with high concentrations have poor biodegradability, which often leads to a significant reduction in the treatment efficiency of conventional wastewater treatment processes and a high effluent color. (3) The wastewater is more likely to contain toxic and harmful substances. The petroleum, fine chemical and synthetic chemical industries often use toxic and harmful substances as catalysts in their production processes, so the wastewater they produce will inevitably contain such substances, which are toxic and harmful to microorganisms, animals and plants. Such as halogenated organic and inorganic compounds, nitro-containing organic compounds, alkali metal phosphate inorganic compounds with antibacterial and bactericidal effects, and various complex dispersants and surfactants.

[0004] Currently, adsorption technology is a simple and effective wastewater treatment technique, widely used in the treatment of industrial wastewater containing heavy metal ions, dye wastewater, petrochemical wastewater, etc. Common technologies for industrial wastewater treatment include activated carbon adsorption and zeolite exchange. Chinese patent CN112169748A discloses an adsorbent, its preparation method, and its application. This adsorbent includes titanium hexametaphosphate, which is mainly prepared from hexametaphosphate and titanium salt. This adsorbent is an aggregate of micron- or nano-sized particles, possessing a large surface area and excellent adsorption performance. Using it as a wastewater treatment agent, it can effectively remove thallium pollutants from various water bodies, including groundwater, surface water, chemical wastewater, and mining wastewater, achieving a removal rate of 99.8%. Furthermore, this adsorbent also exhibits good removal capabilities for heavy metals such as cadmium, lead, copper, antimony, cesium, and uranium in water. The adsorbent has a wide applicable pH range, exhibiting excellent adsorption capacity, stability, and heat resistance, especially under acidic conditions. The preparation method is simple to operate, requires low reaction conditions, and is inexpensive. However, this adsorbent only has a good adsorption effect on heavy metals in wastewater. Chemical wastewater has a complex composition and contains a large amount of organic matter. Whether it is suitable for adsorbing chemical wastewater remains to be discussed.

[0005] Due to the unique characteristics of chemical wastewater, it often contains multiple pollutants, which may interact and affect each other's removal efficiency. Therefore, developing a multifunctional adsorbent to achieve the synergistic removal and adsorption of multiple pollutants is a crucial technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] To address the shortcomings of existing technologies, the present invention aims to provide an adsorbent material for wastewater treatment and its preparation method. This adsorbent has high adsorption capacity, low treatment cost, and can simultaneously adsorb heavy metal ions and organic pollutants, showing promising application prospects.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0009] S1. Preparation of porous biochar: Biomass powder is added to sodium hydroxide solution, stirred evenly, and then potassium permanganate is added for impregnation treatment. After treatment, the mixture is filtered and dried to obtain solid powder. The solid powder is then mixed with urea and calcined. After calcination, porous biochar is obtained.

[0010] S2. Pretreatment of porous biochar: The porous biochar from step S1 is added to an ethanol aqueous solution, followed by the addition of vinyltriethoxysilane. The mixture is stirred and reacted. After the reaction is completed, the mixture is filtered, washed, and dried to obtain pretreated porous biochar.

[0011] S3. Preparation of modified porous biochar: The pretreated porous biochar from step S2 is added to deionized water, followed by the addition of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and ammonium persulfate. The mixture is subjected to a constant temperature reaction. After the reaction is completed, the mixture is filtered, washed, and dried to obtain modified porous biochar.

[0012] S4. Preparation of modified sepiolite: Sepiolite was added to an ethanol aqueous solution, followed by the addition of γ-aminopropyltriethoxysilane. The mixture was stirred and then filtered, washed, and dried to obtain modified sepiolite.

[0013] S5. Preparation of adsorbent material: The modified porous biochar from step S3 and the modified sepiolite from step S4 are added to deionized water and stirred evenly. Then, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine are added. The mixture is heated under a nitrogen atmosphere. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the adsorbent material.

[0014] Preferably, the biomass powder in step S1 is one or more of corn stalk powder, rice stalk powder, and sorghum stalk powder; the concentration of the sodium hydroxide solution is 5-10 wt%; the mass ratio of the biomass powder, sodium hydroxide solution, and potassium permanganate is 100-150:2000-2500:5-10; and the impregnation treatment temperature is 40-50℃ for 2-3 hours.

[0015] More preferably, the biomass powder in step S1 is corn stalk powder, the concentration of the sodium hydroxide solution is 10 wt%, the mass ratio of the biomass powder, sodium hydroxide solution and potassium permanganate is 120-140:2200-2400:7-9, the temperature of the impregnation treatment is 45-50℃, and the time is 2-2.5h.

[0016] In this invention, biomass powder is first treated with alkali to destroy the cellulose structure inside the biomass and make it loose. At the same time, potassium permanganate is added to dope the porous biochar with manganese, thereby improving the biochar's ability to adsorb heavy metals.

[0017] Preferably, the mass ratio of the solid powder to urea in step S1 is 100:20-30; the calcination temperature is 400-500℃ and the time is 1-2h.

[0018] More preferably, in step S1, the mass ratio of the solid powder to urea is 100:25-30; the calcination temperature is 450-500℃, and the time is 1-1.5h.

[0019] In this invention, pretreated biomass is mixed with urea and calcined to incorporate nitrogen atoms into the carbon atom framework, thereby enhancing the adsorption performance of biochar.

[0020] Preferably, in step S2, the volume ratio of ethanol to water in the aqueous ethanol solution is 3:1-2, the mass ratio of porous biochar to vinyltriethoxysilane is 50-70:6-10, and the stirring reaction temperature is 60-70℃ for 2-4 hours.

[0021] More preferably, in step S2, the volume ratio of ethanol to water in the aqueous ethanol solution is 3:1, the mass ratio of porous biochar to vinyltriethoxysilane is 60-70:8-10, the temperature of the stirring reaction is 65-70℃, and the time is 2-3h.

[0022] In this invention, double bond groups are introduced onto the surface of porous biochar by reacting vinyltriethoxysilane with porous biochar, which is beneficial for subsequent reactions.

[0023] Preferably, in step S3, the mass ratio of pretreated porous biochar, deionized water, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, and ammonium persulfate is 50-70:800-900:8-12:0.5-1.

[0024] More preferably, in step S3, the mass ratio of pretreated porous biochar, deionized water, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, and ammonium persulfate is 60-70:850-900:10-12:0.7-1.

[0025] In this invention, the added sodium 3-allyloxy-2-hydroxy-1-propanesulfonate can react with the pretreated biochar to introduce sulfonic acid groups, thereby increasing the adsorption capacity of the adsorbent material for heavy metal cations.

[0026] Preferably, the isothermal reaction in step S3 is carried out at a temperature of 80-90°C for 5-8 hours.

[0027] More preferably, the isothermal reaction in step S3 is carried out at a temperature of 85-90°C for 5-7 hours.

[0028] Preferably, in step S4, the volume ratio of ethanol to water in the aqueous ethanol solution is 3:1-2, and the mass ratio of sepiolite to γ-aminopropyltriethoxysilane is 30-50:5-8; the stirring treatment is carried out at a temperature of 60-70°C for 3-5 hours.

[0029] More preferably, in step S4, the volume ratio of ethanol to water in the aqueous ethanol solution is 3:1, and the mass ratio of sepiolite to γ-aminopropyltriethoxysilane is 30-40:5-7; the stirring treatment is carried out at a temperature of 65-70°C for 3-4 hours.

[0030] In this invention, sepiolite is modified by γ-aminopropyltriethoxysilane, which can improve the dispersibility of sepiolite and introduce amino groups on the surface of sepiolite, which is beneficial to the subsequent reaction.

[0031] Preferably, the mass ratio of the modified porous biochar, modified sepiolite, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine in step S5 is 50-70:30-50:15-25:20-30:40-60.

[0032] More preferably, the mass ratio of the modified porous biochar, modified sepiolite, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine in step S5 is 60-70:30-40:20-25:25-30:50-60.

[0033] Preferably, the heating reaction in step S5 is carried out at a temperature of 75-85°C for 6-10 hours.

[0034] More preferably, the heating reaction in step S5 is carried out at a temperature of 80-85°C for 6-8 hours.

[0035] In this invention, glutaraldehyde is used as a crosslinking agent to graft modified sepiolite, modified biochar, and hydroxypropyl-β-cyclodextrin together. Hydroxypropyl-β-cyclodextrin can adsorb organic pollutants in wastewater through inclusion complexation, thereby improving the adsorption capacity of the adsorption material for organic pollutants.

[0036] The present invention also protects an adsorbent material for treating wastewater prepared by the method described above.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] (1) The adsorbent material for treating wastewater provided by the present invention is a porous biochar prepared by a specific method, which makes the prepared porous biochar have a large specific surface area and surface activity, thereby improving the adsorption performance of the biochar. Then, functional functional groups are introduced on the surface of the porous biochar by chemical modification, which improves the adsorbent material's ability to treat heavy metal pollutants and organic pollutants in chemical wastewater at the same time, expands the application range of the adsorbent material, and has good application prospects.

[0039] (2) The adsorbent material for wastewater treatment provided by this invention first involves adding biomass powder to a sodium hydroxide solution, along with potassium permanganate, and then performing alkaline heat treatment. This makes the biomass more porous. The added potassium permanganate can be incorporated into the biomass and decomposes during subsequent calcination, generating gas that forms a porous structure in the biochar, increasing its specific surface area. Then, the solid powder is mixed with urea and calcined to incorporate nitrogen into the porous biochar. When nitrogen atoms are incorporated into the carbon skeleton of the biochar, they replace the carbon atoms in their original positions. The lone pair electrons on the nitrogen atoms provide electrons to the sp2 hybridized π electrons in the carbon skeleton, increasing the electron cloud density on the biochar surface. This results in the porous biochar having better hydrophilicity and higher surface activity. Finally, the porous biochar is further processed... The pretreated biochar undergoes ethylene treatment, followed by reaction with sodium 3-allyloxy-2-hydroxy-1-propanesulfonate. Through double bond addition, hydroxyl and sulfonic acid groups are introduced onto the biochar, increasing its hydrophilicity and enhancing its adsorption capacity for heavy metal ions. Next, sepiolite is aminated to introduce amino groups onto its surface, improving its reactivity. Finally, glutaraldehyde is used as a crosslinking agent to graft modified sepiolite, modified biochar, and hydroxypropyl-β-cyclodextrin via aldol condensation. This enhances the adsorption capacity of the adsorbent material for organic pollutants. Compared to physical blending, chemical grafting improves the stability and strength of the adsorbent material, while preventing the organic components from detaching, thus avoiding secondary pollution.

[0040] (3) The adsorbent material for treating wastewater provided by the present invention combines modified porous biochar and modified sepiolite to give full play to their respective advantages. At the same time, hydroxypropyl-β-cyclodextrin is introduced. The three work together to adsorb heavy metal ions and organic pollutants in chemical wastewater. After adsorption, the adsorbent material can be separated by filtration, which greatly improves the operability of the adsorbent material. The method is simple and easy to implement and will not produce secondary pollution. Detailed Implementation

[0041] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] In this invention, the sepiolite was purchased from Shijiazhuang Chengao New Material Technology Co., Ltd., with a mesh size of 400; the hydroxypropyl-β-cyclodextrin was purchased from Hubei Xinghengye Technology Co., Ltd.

[0043] Example 1

[0044] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0045] S1. Preparation of porous biochar: 130g of corn stalk powder was added to 2300g of 10wt% sodium hydroxide solution, stirred evenly, and then 8g of potassium permanganate was added. The mixture was impregnated at 45℃ for 2.5h. After the treatment, the mixture was filtered and dried to obtain solid powder. Then, 100g of solid powder was mixed with 25g of urea and placed in a tube furnace. The mixture was calcined at 450℃ for 1.5h. After calcination, the mixture was cooled to room temperature to obtain porous biochar.

[0046] S2. Pretreatment of porous biochar: 60g of porous biochar from step S1 was added to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 8g of vinyltriethoxysilane. The mixture was stirred at 65℃ for 3h. After the reaction was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain pretreated porous biochar.

[0047] S3. Preparation of modified porous biochar: 60g of pretreated porous biochar from step S2 was added to 850g of deionized water, followed by 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 0.8g of ammonium persulfate. The mixture was reacted at 85℃ for 7h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 4h to obtain modified porous biochar.

[0048] S4. Preparation of modified sepiolite: 40g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 7g of γ-aminopropyltriethoxysilane. The mixture was stirred at 65℃ for 4h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0049] S5. Preparation of adsorbent material: 60g of modified porous biochar from step S3 and 40g of modified sepiolite from step S4 were added to 1500g of deionized water and stirred evenly. Then, 20g of glutaraldehyde, 25g of hydroxypropyl-β-cyclodextrin and 50g of triethylamine were added. The mixture was reacted at 80°C for 8 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80°C for 3 hours to obtain the adsorbent material.

[0050] Example 2

[0051] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0052] S1. Preparation of porous biochar: 120g of rice straw powder was added to 2300g of 5wt% sodium hydroxide solution, stirred evenly, and then 7g of potassium permanganate was added. The mixture was impregnated at 45℃ for 2.5h. After the treatment, the mixture was filtered and dried to obtain solid powder. Then, 100g of solid powder was mixed with 25g of urea and placed in a tube furnace. The mixture was calcined at 450℃ for 1.5h. After calcination, the mixture was cooled to room temperature to obtain porous biochar.

[0053] S2. Pretreatment of porous biochar: 65g of porous biochar from step S1 was added to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 3:2), followed by 8g of vinyltriethoxysilane. The mixture was stirred at 65℃ for 3h. After the reaction was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain pretreated porous biochar.

[0054] S3. Preparation of modified porous biochar: 65g of pretreated porous biochar from step S2 was added to 850g of deionized water, followed by 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 0.8g of ammonium persulfate. The mixture was reacted at 85℃ for 6h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 4h to obtain modified porous biochar.

[0055] S4. Preparation of modified sepiolite: 35g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:2), followed by 6g of γ-aminopropyltriethoxysilane. The mixture was stirred at 65℃ for 4h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0056] S5. Preparation of adsorbent material: 65g of modified porous biochar from step S3 and 35g of modified sepiolite from step S4 were added to 1500g of deionized water and stirred evenly. Then, 20g of glutaraldehyde, 25g of hydroxypropyl-β-cyclodextrin and 50g of triethylamine were added. The mixture was reacted at 80°C for 8 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80°C for 3 hours to obtain the adsorbent material.

[0057] Example 3

[0058] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0059] S1. Preparation of porous biochar: 100g of sorghum straw powder was added to 2000g of 10wt% sodium hydroxide solution, stirred evenly, and then 5g of potassium permanganate was added. The mixture was impregnated at 40℃ for 3h. After the treatment, it was filtered and dried to obtain solid powder. Then, 100g of solid powder was mixed with 20g of urea and placed in a tube furnace. The mixture was calcined at 400℃ for 2h. After calcination, it was cooled to room temperature to obtain porous biochar.

[0060] S2. Pretreatment of porous biochar: 50g of porous biochar from step S1 was added to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 6g of vinyltriethoxysilane. The mixture was stirred at 60℃ for 4h. After the reaction was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain pretreated porous biochar.

[0061] S3. Preparation of modified porous biochar: 50g of pretreated porous biochar from step S2 was added to 800g of deionized water, followed by 8g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 0.5g of ammonium persulfate. The mixture was reacted at 80℃ for 8h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 4h to obtain modified porous biochar.

[0062] S4. Preparation of modified sepiolite: 50g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 5g of γ-aminopropyltriethoxysilane. The mixture was stirred at 60℃ for 5h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0063] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S3 and 30g of modified sepiolite from step S4 were added to 1500g of deionized water and stirred evenly. Then, 15g of glutaraldehyde, 20g of hydroxypropyl-β-cyclodextrin and 40g of triethylamine were added. The mixture was reacted at 75°C under a nitrogen atmosphere for 10h. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80°C for 3h to obtain the adsorbent material.

[0064] Example 4

[0065] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0066] S1. Preparation of porous biochar: 150g of corn stalk powder was added to 2500g of 5wt% sodium hydroxide solution, stirred evenly, and then 10g of potassium permanganate was added. The mixture was impregnated at 50℃ for 2h. After the treatment, it was filtered and dried to obtain solid powder. Then, 100g of solid powder was mixed with 30g of urea and placed in a tube furnace. The mixture was calcined at 500℃ for 1h. After calcination, it was cooled to room temperature to obtain porous biochar.

[0067] S2. Pretreatment of porous biochar: 70g of porous biochar from step S1 was added to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 3:2), followed by the addition of 10g of vinyltriethoxysilane. The mixture was stirred at 70℃ for 2h. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain pretreated porous biochar.

[0068] S3. Preparation of modified porous biochar: 70g of pretreated porous biochar from step S2 was added to 900g of deionized water, followed by 12g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 1g of ammonium persulfate. The mixture was reacted at 90℃ for 5h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 4h to obtain modified porous biochar.

[0069] S4. Preparation of modified sepiolite: 30g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:2), followed by 8g of γ-aminopropyltriethoxysilane. The mixture was stirred at 70℃ for 3h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0070] S5. Preparation of adsorbent material: 70g of modified porous biochar from step S3 and 30g of modified sepiolite from step S4 were added to 1500g of deionized water and stirred evenly. Then, 25g of glutaraldehyde, 30g of hydroxypropyl-β-cyclodextrin and 60g of triethylamine were added. The mixture was reacted at 85°C for 6 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80°C for 3 hours to obtain the adsorbent material.

[0071] Comparative Example 1

[0072] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0073] S1. Preparation of porous biochar: 130g of corn stalk powder was placed in a tube furnace and calcined at 450℃ for 1.5h. After calcination, the mixture was cooled to room temperature to obtain porous biochar.

[0074] S2. Pretreatment of porous biochar: 60g of porous biochar from step S1 was added to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 8g of vinyltriethoxysilane. The mixture was stirred at 65℃ for 3h. After the reaction was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain pretreated porous biochar.

[0075] S3. Preparation of modified porous biochar: 60g of pretreated porous biochar from step S2 was added to 850g of deionized water, followed by 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 0.8g of ammonium persulfate. The mixture was reacted at 85℃ for 7h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 4h to obtain modified porous biochar.

[0076] S4. Preparation of modified sepiolite: 40g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 7g of γ-aminopropyltriethoxysilane. The mixture was stirred at 65℃ for 4h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0077] S5. Preparation of adsorbent material: 60g of modified porous biochar from step S3 and 40g of modified sepiolite from step S4 were added to 1500g of deionized water and stirred evenly. Then, 20g of glutaraldehyde, 25g of hydroxypropyl-β-cyclodextrin and 50g of triethylamine were added. The mixture was reacted at 80°C for 8 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80°C for 3 hours to obtain the adsorbent material.

[0078] Comparative Example 2

[0079] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0080] S1. Preparation of porous biochar: 130g of corn stalk powder was added to 2300g of 10wt% sodium hydroxide solution, stirred evenly, and then 8g of potassium permanganate was added. The mixture was impregnated at 45℃ for 2.5h. After the treatment, the mixture was filtered and dried to obtain solid powder. Then, 100g of solid powder was mixed with 25g of urea and placed in a tube furnace. The mixture was calcined at 450℃ for 1.5h. After calcination, the mixture was cooled to room temperature to obtain porous biochar.

[0081] S2. Pretreatment of porous biochar: 60g of porous biochar from step S1 was added to 800mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 8g of vinyltriethoxysilane. The mixture was stirred at 65℃ for 3h. After the reaction was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain pretreated porous biochar.

[0082] S3. Preparation of modified porous biochar: 60g of pretreated porous biochar from step S2 was added to 850g of deionized water, followed by 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 0.8g of ammonium persulfate. The mixture was reacted at 85℃ for 7h. After the reaction was completed, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 4h to obtain modified porous biochar.

[0083] S4. Preparation of modified sepiolite: 40g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 7g of γ-aminopropyltriethoxysilane. The mixture was stirred at 65℃ for 4h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0084] S5. Preparation of adsorbent material: 60g of modified porous biochar from step S3 and 40g of modified sepiolite from step S4 are added to 1500g of deionized water, stirred evenly, filtered, and dried at 80℃ for 3h to obtain the adsorbent material.

[0085] Comparative Example 3

[0086] A method for preparing an adsorbent material for treating wastewater includes the following steps:

[0087] S1. Preparation of porous biochar: 130g of corn stalk powder was added to 2300g of 10wt% sodium hydroxide solution, stirred evenly, and then 8g of potassium permanganate was added. The mixture was impregnated at 45℃ for 2.5h. After the treatment, the mixture was filtered and dried to obtain solid powder. Then, 100g of solid powder was mixed with 25g of urea and placed in a tube furnace. The mixture was calcined at 450℃ for 1.5h. After calcination, the mixture was cooled to room temperature to obtain porous biochar.

[0088] S2. Preparation of modified sepiolite: 40g sepiolite was added to 600mL of ethanol aqueous solution (ethanol to water volume ratio of 3:1), followed by 7g of γ-aminopropyltriethoxysilane. The mixture was stirred at 65℃ for 4h. After the treatment was completed, the mixture was filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain modified sepiolite.

[0089] S3. Preparation of adsorbent material: 60g of porous biochar from step S3 and 40g of modified sepiolite from step S2 were added to 1500g of deionized water and stirred evenly. Then, 20g of glutaraldehyde, 25g of hydroxypropyl-β-cyclodextrin and 50g of triethylamine were added. The mixture was reacted at 80°C for 8 hours under a nitrogen atmosphere. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80°C for 3 hours to obtain the adsorbent material.

[0090] The adsorbent materials prepared in Examples 1-4 and Comparative Examples 1-3 were used to conduct adsorption treatment experiments on chemical wastewater. The specific steps are as follows: Simulated wastewater was used, and 1L of wastewater was prepared, containing Cd... 2+ Cu 2+ Ni 2+ Pb 2+ The concentrations of all pollutants were 300 mg / L, and the concentrations of methyl orange and aniline were 100 mg / L. Seven 250 mL Erlenmeyer flasks were taken, and 100 mL of simulated industrial wastewater was added to each flask. Then, 1 g of the adsorbent prepared in Examples 1-4 and Comparative Examples 1-3 was added to each flask. The flasks were placed in a constant temperature shaker under natural light. The shaker temperature was set at 25°C, the rotation speed at 250 rpm, and the shaking time was 2 h. After shaking, the solution was filtered through a microporous membrane, and the concentrations of each pollutant in the solution were measured. The average value was taken for three tests, and the removal rate was calculated. The test results are shown in Table 1 below.

[0091] Table 1

[0092]

[0093] As can be seen from Table 1 above, the adsorbent material prepared by the present invention has good adsorption capacity for heavy metal ions and organic pollutants. It can simultaneously adsorb heavy metal ions and organic pollutants in wastewater and has good application prospects.

[0094] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an adsorbent material for treating wastewater, characterized in that, Includes the following steps: S1. Preparation of porous biochar: Biomass powder is added to sodium hydroxide solution, stirred evenly, and then potassium permanganate is added for impregnation treatment. After treatment, the mixture is filtered and dried to obtain solid powder. The solid powder is then mixed with urea and calcined. After calcination, porous biochar is obtained. S2. Pretreatment of porous biochar: The porous biochar from step S1 is added to an ethanol aqueous solution, followed by the addition of vinyltriethoxysilane. The mixture is stirred and reacted. After the reaction is completed, the mixture is filtered, washed, and dried to obtain pretreated porous biochar. S3. Preparation of modified porous biochar: The pretreated porous biochar from step S2 is added to deionized water, followed by the addition of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and ammonium persulfate. The mixture is subjected to a constant temperature reaction. After the reaction is completed, the mixture is filtered, washed, and dried to obtain modified porous biochar. S4. Preparation of modified sepiolite: Sepiolite was added to an ethanol aqueous solution, followed by the addition of γ-aminopropyltriethoxysilane. The mixture was stirred and then filtered, washed, and dried to obtain modified sepiolite. S5. Preparation of adsorbent material: The modified porous biochar from step S3 and the modified sepiolite from step S4 are added to deionized water and stirred evenly. Then, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine are added. The mixture is heated under a nitrogen atmosphere. After the reaction is completed, the mixture is filtered, washed, and dried to obtain the adsorbent material.

2. The preparation method according to claim 1, characterized in that, The biomass powder mentioned in step S1 is one or more of corn stalk powder, rice stalk powder, and sorghum stalk powder; the concentration of the sodium hydroxide solution is 5-10 wt%; the mass ratio of the biomass powder, sodium hydroxide solution, and potassium permanganate is 100-150:2000-2500:5-10; the impregnation treatment temperature is 40-50℃; and the time is 2-3 hours.

3. The preparation method according to claim 1, characterized in that, The mass ratio of the solid powder to urea in step S1 is 100:20-30; the calcination temperature is 400-500℃ and the time is 1-2h.

4. The preparation method according to claim 1, characterized in that, In step S2, the volume ratio of ethanol to water in the aqueous ethanol solution is 3:1-2, the mass ratio of porous biochar to vinyltriethoxysilane is 50-70:6-10, and the stirring reaction is carried out at a temperature of 60-70°C for 2-4 hours.

5. The preparation method according to claim 1, characterized in that, In step S3, the mass ratio of pretreated porous biochar, deionized water, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, and ammonium persulfate is 50-70:800-900:8-12:0.5-1.

6. The preparation method according to claim 1, characterized in that, The isothermal reaction in step S3 is carried out at a temperature of 80-90℃ for 5-8 hours.

7. The preparation method according to claim 1, characterized in that, In step S4, the volume ratio of ethanol to water in the aqueous ethanol solution is 3:1-2, and the mass ratio of sepiolite to γ-aminopropyltriethoxysilane is 30-50:5-8; the stirring treatment is carried out at a temperature of 60-70℃ for 3-5 hours.

8. The preparation method according to claim 1, characterized in that, The mass ratio of modified porous biochar, modified sepiolite, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine in step S5 is 50-70:30-50:15-25:20-30:40-60.

9. The preparation method according to claim 1, characterized in that, The heating reaction in step S5 is carried out at a temperature of 75-85°C for 6-10 hours.

10. An adsorbent material for treating wastewater prepared by the method according to any one of claims 1-9.

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