A high-efficiency adsorbent material for treating wastewater and a preparation method thereof

Abstract

This invention relates to the field of chemical wastewater treatment technology, and in particular to a highly efficient adsorbent material for wastewater treatment and its preparation method. The process includes the following steps: S1, mixing pretreated biomass powder with sodium bicarbonate and calcining to prepare porous biochar; S2, reacting the porous biochar with γ-mercaptopropyltrioxysilane to obtain thiolated porous biochar; S3, reacting the thiolated porous biochar with sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and 2,2-dimethoxy-2-phenylethyl ketone to obtain modified porous biochar; S4, adding pulverized bentonite to a mixture of polydimethyldiallyl ammonium chloride and chitosan, and reacting at a constant temperature to obtain composite bentonite; then modifying the composite bentonite with thiolation to obtain modified bentonite; S5, adding the modified porous biochar from step S4 and the modified bentonite from step S5 to deionized water, stirring evenly, then adding glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine, and heating the mixture under a nitrogen atmosphere to obtain the adsorbent material. The porous biochar in the high-efficiency adsorbent material prepared by this invention has a large specific surface area and surface activity, which improves the adsorption performance of the biochar. Then, functional groups are introduced on the surface of the porous biochar by chemical modification, which improves the adsorbent material's ability to simultaneously treat heavy metal pollutants and organic pollutants in chemical wastewater, and expands the application range of the adsorbent material.

Description

Technical Field

[0001] This invention relates to the field of chemical wastewater treatment technology, and in particular to a highly efficient adsorbent material for wastewater treatment 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 CN114247419A describes an adsorbent primarily obtained by modifying a solid catalyst with alkali and lanthanum ions; the main components of the solid catalyst include SiO2, Al2O3, and Fe3O4. The raw material for this adsorbent is a Fischer-Tropsch synthesis waste catalyst, which, after modification, can be reused as an adsorbent for wastewater treatment. It has low adsorption costs and can effectively adsorb fluoride ions in coal chemical wastewater. However, this adsorbent only has a good adsorption effect on fluoride ions in wastewater. Chemical wastewater has a complex composition, containing various harmful chemical substances such as organic matter, heavy metals, and organic solvents. These various pollutants may interact and affect the adsorption efficiency of the adsorbent. Summary of the Invention

[0005] In view of this, the present invention proposes a high-efficiency adsorbent material for treating wastewater and its preparation method, in order to solve the problem that the adsorbent in the prior art has low adsorption efficiency and is difficult to achieve synergistic removal of multiple pollutants such as organic matter, heavy metals, and organic solvents.

[0006] The technical solution of this invention is implemented as follows:

[0007] In a first aspect, the present invention provides a method for preparing a highly efficient adsorbent material for treating wastewater, comprising the following steps:

[0008] S1. Preparation of porous biochar: Pretreated biomass powder is mixed with sodium bicarbonate and calcined under a nitrogen atmosphere. After calcination, it is cooled to room temperature, washed and dried to obtain porous biochar.

[0009] S2. Preparation of thiolized porous biochar: Porous biochar was added to an aqueous ethanol solution, followed by the addition of γ-mercaptopropyltrioxysilane, and ball milling was performed. After the reaction was completed, the mixture was filtered, washed, and dried to obtain thiolized porous biochar.

[0010] S3. Preparation of modified porous biochar: Thiol-modified porous biochar was added to deionized water, followed by the addition of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone. The reaction was carried out under ultraviolet light at a constant temperature with an intensity of 10-20 mW / cm². 2 After the reaction is complete, the mixture is filtered, washed, and dried to obtain modified porous biochar.

[0011] S4. Preparation of modified bentonite: The pulverized bentonite was added to a mixture of polydimethyldiallylammonium chloride and chitosan and reacted at a constant temperature. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite bentonite. Then, the composite bentonite, 3-mercaptoisobutyrylglycine, and concentrated sulfuric acid were mixed and reacted in a water bath. After the reaction was completed, the mixture was filtered, washed, and dried to obtain modified bentonite.

[0012] S5. Preparation of adsorbent material: The modified porous biochar from step S4 and the modified bentonite from step S5 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.

[0013] In this invention, in step S1, by mixing with sodium bicarbonate and calcining under a nitrogen atmosphere, the gas released by the decomposition of sodium bicarbonate at high temperature forms pores inside the matrix, thereby generating a large number of micropores and mesopores on the biomass matrix, significantly increasing the specific surface area and porosity of the biochar. In step S2, by reacting with γ-mercaptopropyltrioxysilane, the alkoxy groups in γ-mercaptopropyltrioxysilane hydrolyze in an aqueous ethanol solution to generate silanol, which then undergoes a condensation reaction with the hydroxyl groups on the surface of the biochar to form stable silicon-oxygen bonds, thereby introducing thiol functional groups onto the porous biochar surface. In step S3, the ultraviolet initiator (2,2-dimethoxy-2-phenylethyl ketone) generates free radicals under ultraviolet light irradiation, initiating the polymerization reaction of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate on the biochar surface, thereby introducing sulfonic acid-containing polymer chains onto the biochar surface. The modified biochar prepared by the above scheme has a high specific surface area and a well-developed pore structure, providing a large number of adsorption sites. It can adsorb organic molecules through physical adsorption (such as van der Waals forces). At the same time, sulfonic acid groups are introduced on the surface of porous biochar. The sulfonic acid functional groups can capture heavy metal cations in water through electrostatic attraction. Furthermore, the hydrophilicity of sulfonic acid groups can improve the dispersibility and environmental adaptability of the carbon material.

[0014] In step S4, bentonite is a layered silicate clay mineral with exchangeable cations (such as Na+) between its layers. + Ca 2+ (etc.). When bentonite is mixed with polydiallyl ammonium chloride and chitosan, the cationic groups (such as quaternary ammonium groups) in the polydiallyl ammonium chloride and chitosan molecules can simultaneously enter the bentonite interlayer through cation exchange, replacing the original inorganic cations. This leads to an increase in the interlayer spacing of the bentonite. The oleophilic regions in the bentonite interlayer can partition with organic molecules, trapping them in the interlayer space. Then, the composite bentonite undergoes secondary modification. Under acidic conditions, the carboxyl group in 3-mercaptoisobutyrylglycine undergoes an amidation reaction with the amino group on the chitosan molecule, introducing a high density of thiol functional groups onto the chitosan molecule. Thiol groups are soft basic ligands that can form coordination bonds with soft acidic organic pollutants, selectively adsorbing them. Simultaneously, thiol functional groups can also selectively chelate heavy metal ions through coordination, significantly improving the adsorption performance of carbon materials for heavy metals. In step S5, glutaraldehyde is used as a crosslinking agent to graft modified bentonite, modified biochar, and hydroxypropyl-β-cyclodextrin through aldol condensation reaction, thereby improving the adsorption capacity of the adsorbent material for organic pollutants. Compared with physical blending, the chemical grafting method improves the stability and strength of the adsorbent material, and at the same time, the organic components in the adsorbent material are not easily detached, thus avoiding secondary pollution.

[0015] Based on the above technical solutions, preferably, the pretreatment method of biomass powder in step S1 includes: adding biomass powder to phosphoric acid solution, stirring, and after the treatment is completed, filtering, washing, and drying to obtain biomass powder pretreated with phosphoric acid.

[0016] Based on the above technical solutions, preferably, the biomass powder includes one or more of corn straw powder, rice straw powder, sorghum straw powder and wheat straw powder, the concentration of the phosphoric acid solution is 0.5-1.0 mol / L, the mass ratio of the biomass powder to the phosphoric acid solution is 1:2-1:20, the stirring temperature is 75-85℃, and the stirring time is 1.5-2.5h.

[0017] In this invention, phosphoric acid pretreatment promotes the dehydration and deoxygenation reactions of biomass during carbonization, generating more micropores and mesopores, significantly increasing the specific surface area and porosity of biochar. Simultaneously, phosphoric acid introduces more oxygen-containing functional groups (such as carboxyl, hydroxyl, and phosphate groups) onto the surface of biochar, enhancing its hydrophilicity and polarity, which is beneficial for adsorbing polar pollutants. Furthermore, phosphoric acid can form thermally stable phosphates with inorganic substances in biomass (such as potassium and calcium), inhibiting the shrinkage and collapse of biochar during high-temperature carbonization and maintaining its porous structure.

[0018] Based on the above technical solutions, preferably, in step S1, the mass ratio of pretreated biomass powder to sodium bicarbonate is 1:1.8-2.2, the calcination temperature is 400-600℃, and the time is 1-2h.

[0019] Based on the above technical solution, preferably, in step S2, the porous biochar powder is placed in a ball mill jar, and an aqueous ethanol solution and γ-mercaptopropyltrioxysilane are added. The ball milling reaction is carried out at room temperature, first at a speed of 200-300 rpm for 0.5-1 hour, with the milling direction changed every 20 minutes; then at a speed of 400-500 rpm for 15-40 minutes, with the milling direction changed every 10 minutes. More preferably, the volume ratio of ethanol to water in the aqueous ethanol solution is 1:3-4.

[0020] In this invention, wet ball milling disrupts the agglomeration of biochar particles under mechanical force, resulting in uniform dispersion and increased contact area with γ-mercaptopropyltrioxysilane, thus promoting the thiolization reaction. The high shear force and localized high temperature generated by ball milling increase the kinetic energy and collision frequency of reactant molecules, accelerating the reaction process. Wet ball milling utilizes the wetting effect of the ethanol-water solution to improve the contact between silane and the biochar surface, promoting uniform thiol grafting. Furthermore, initial low-speed ball milling disrupts biochar particle agglomeration under milder conditions, ensuring uniform dispersion; secondary high-speed ball milling further increases the grafting density of thiol groups on the biochar surface, increasing thiol content and improving the material's adsorption performance. This secondary ball milling also avoids the excessive fragmentation of porous biochar particles caused by direct high-speed ball milling.

[0021] Based on the above technical solutions, preferably, in step S2, the mass ratio of the porous biochar powder, the ethanol aqueous solution, and γ-mercaptopropyltrioxysilane is 1:5-15:0.08-0.12.

[0022] Based on the above technical solutions, preferably, in step S3, the mass ratio of thiolated porous biochar, deionized water, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, and 2,2-dimethoxy-2-phenylethyl ketone is 45-60:700-800:7-11:0.5-1.

[0023] Based on the above technical solutions, preferably, in step 4, the mass ratio of bentonite, polydimethyldiallylammonium chloride and chitosan is 1:0.6-1:0.01-0.06, and the mass-volume ratio of composite bentonite, 3-mercaptoisobutyrylglycine and concentrated sulfuric acid is 1:0.1-0.3:0.01-0.1.

[0024] Based on the above technical solutions, preferably, in step S5, the mass ratio of modified porous biochar, modified bentonite, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine is 1:0.4-0.6:0.2-0.4:0.3-0.5:0.7-1, the heating reaction temperature is 75-85℃, and the time is 6-10h.

[0025] Secondly, the present invention provides a highly efficient adsorbent material for treating wastewater prepared by the preparation method described in any of the preceding claims.

[0026] The present invention provides a highly efficient adsorbent material for wastewater treatment and its preparation method, which have the following advantages over the prior art:

[0027] (1) The high-efficiency adsorbent material for wastewater treatment provided by the present invention is prepared by first phosphorylation and then carbonization, so that the porous biochar has a large specific surface area and surface activity, which improves 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 adsorption material 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.

[0028] (2) This invention combines modified porous biochar and modified bentonite to leverage their respective advantages, while introducing hydroxypropyl-β-cyclodextrin. Modified porous biochar and modified bentonite provide abundant adsorption sites and surface functional groups, while cyclodextrin provides hydrophobic cavities. During adsorption, hydrophobic organic matter can be selectively encapsulated by cyclodextrin, while hydrophilic organic matter and heavy metal ions can be adsorbed by biochar and bentonite. The three work synergistically and promote each other, improving the adsorption efficiency and selectivity for complex pollutants in petrochemical wastewater. Furthermore, after adsorption, the adsorbent material can be separated by filtration, greatly improving the operability of the adsorbent material. The method is simple and easy to implement and will not generate secondary pollution.

[0029] (3) In the process of preparing thiolized porous biochar in this invention, wet ball milling can avoid the agglomeration of biochar particles, making them evenly dispersed, increasing the contact area with silane coupling agent, and promoting the thiolization reaction; at the same time, combining low-speed ball milling and high-speed ball milling can further increase the grafting density of thiol on the surface of biochar, increase the thiol content, and thus improve the introduction of functional groups, thereby achieving the preparation of a highly efficient adsorbent.

[0030] (4) By inserting chitosan between the bentonite layers, the positive charge and affinity of the bentonite surface are increased, which improves the adsorption capacity for negative ion pollutants. By introducing 3-mercaptoisobutyrylglycine, chitosan is thiolated, and functional groups such as thiol groups with stronger affinity are introduced on the bentonite surface, which can more effectively adsorb pollutants such as heavy metal ions. Detailed Implementation

[0031] The technical solutions of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the 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.

[0032] The 3-mercaptoisobutyrylglycine was prepared according to the literature "Influence of 3-mercaptoisobutyric acid derivatives on aqueous synthesis of cadmium telluride quantum dots, Ma Kaiguo et al., Supplementary Information for ActaPhys.-Chim.Sin.", as detailed below:

[0033] Dissolve 1.6833 g (42 mmol) of NaOH in 15.0 mL of water, and divide the solution into two 7.5 mL portions. Dissolve 1.5047 g (20 mmol) of glycine in one 7.5 mL portion of the NaOH solution, and cool to 0°C using an ice-water bath. Place two constant-pressure dropping funnels on a three-necked flask, and pour the remaining 7.5 mL of NaOH solution into one of the funnels. Add 3.0 mL of dichloromethane and 2.3277 g of methacryloyl chloride to the other funnel. Simultaneously open both funnels and slowly add the two solutions dropwise to the three-necked flask. After the addition is complete, continue the reaction at 5°C for 1 hour. After the reaction is complete, remove the dichloromethane by rotary evaporation at 20°C. After extraction twice with diethyl ether and n-hexane, the pH was adjusted to 2 with concentrated hydrochloric acid, resulting in turbidity. The solution was then extracted five times with 50 mL of ethyl acetate each time. Upon addition of ethyl acetate, a large amount of flocculent precipitate appeared, and the aqueous phase became turbid. The flocculent precipitate was separated, and the oil phase was dried with anhydrous magnesium sulfate. The magnesium sulfate was removed by filtration, and the white, crystalline solid obtained by rotary evaporation was recrystallized with ethyl acetate to yield methacryloylglycine.

[0034] In a three-necked flask, 0.50 g of methacryloxyglycine (3.49 mmol), 30 mL of anhydrous tetrahydrofuran, and 0.53 g of thioacetic acid (6.97 mmol) were added and refluxed overnight. The tetrahydrofuran was removed by rotary evaporation, and the product was dried under vacuum overnight to obtain the crude product (i.e., 3-acetylthioisobutyrylglycine). The crude product was used directly in subsequent reactions without purification.

[0035] In a three-necked flask, crude 3-acetylthioisobutyrylglycine (0.7618 g, 3.47 mmol), deionized water (10 mL), and concentrated ammonia (10 mL) were added. The mixture was stirred until clear and reacted at room temperature for 30 min. After acidification to pH 2 with concentrated hydrochloric acid, the mixture was extracted with ethyl acetate (6 × 50 mL), and the organic phase was dried over anhydrous magnesium sulfate overnight. The solvent was removed by rotary evaporation to obtain a white solid (crude product). The crude product was recrystallized from ethyl acetate to obtain a white solid, which was 3-mercaptoisobutyrylglycine.

[0036] In this invention, the bentonite was purchased from Henan Jingchuan Environmental Protection Technology Co., Ltd., with a mesh size of 200; the hydroxypropyl-β-cyclodextrin was purchased from Hubei Xinghengye Technology Co., Ltd.

[0037] Example 1

[0038] This embodiment provides a highly efficient adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0039] S1. Preparation of porous biochar: 100g of corn stalk powder was added to 1000g of 0.8mol / L phosphoric acid solution and stirred at 80℃ for 2h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain phosphoric acid pretreated biomass powder. 80g of pretreated biomass powder was mixed with 160g of sodium bicarbonate and calcined at 500℃ under a nitrogen atmosphere for 1h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0040] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 600g of ethanol aqueous solution (ethanol to water volume ratio of 1:3.5), and then 6g of γ-mercaptopropyltrioxysilane was added. The mixture was ball-milled at 250rpm for 45min at room temperature, with the milling direction changed every 20min. Then it was ball-milled at 450rpm for 30min, with the milling direction changed every 10min. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0041] S3. Preparation of modified porous biochar: 50g of mercapto-modified porous biochar was added to 750g of deionized water, followed by the addition of 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 0.8g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 8ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 15mW / cm². 2 The mixture was reacted at a constant temperature of 85℃ for 6 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0042] S4. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 80g of polydimethyldiallylammonium chloride and 4g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 4g of chitosan was dissolved in 40ml of 0.1M hydrochloric acid solution. The mixture was reacted at 60℃ for 6h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 800g of deionized water, followed by 16g of 3-mercaptoisobutyrylglycine and 5ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 40℃ for 16h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0043] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S4 and 25g of modified bentonite from step S5 were added to 1000g 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 80°C under a nitrogen atmosphere for 8 hours. 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 high-efficiency adsorbent material.

[0044] Example 2

[0045] This embodiment provides a highly efficient adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0046] S1. Preparation of porous biochar: 100g of wheat straw powder was added to 500g of 0.5mol / L phosphoric acid solution and stirred at 80℃ for 2h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain phosphoric acid pretreated biomass powder. 80g of pretreated wheat straw powder was mixed with 150g of sodium bicarbonate and calcined at 500℃ under a nitrogen atmosphere for 1.5h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0047] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 480g of ethanol aqueous solution (ethanol to water volume ratio of 1:3), and then 5.4g of γ-mercaptopropyltrioxysilane was added. The mixture was ball-milled at 250rpm for 30min at room temperature, with the milling direction changed every 20min. Then it was ball-milled at 450rpm for 25min, with the milling direction changed every 10min. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0048] S3. Preparation of modified porous biochar: 60g of mercapto-modified porous biochar was added to 700g of deionized water, followed by the addition of 7g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 0.6g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 6ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 18mW / cm². 2 The mixture was reacted at a constant temperature of 80℃ for 5.5 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0049] S4. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 60g of polydimethyldiallylammonium chloride and 6g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 6g of chitosan was dissolved in 60ml of 0.1M hydrochloric acid solution. The mixture was reacted at 55℃ for 6.5h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 700g of deionized water, followed by 24g of 3-mercaptoisobutyrylglycine and 1ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 45℃ for 20h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0050] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S4 and 20g of modified bentonite from step S5 were added to 800g of deionized water and stirred evenly. Then, 20g of glutaraldehyde, 15g of hydroxypropyl-β-cyclodextrin and 50g of triethylamine were added. The mixture was reacted at 75°C under a nitrogen atmosphere for 9 hours. 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 high-efficiency adsorbent material.

[0051] Example 3

[0052] This embodiment provides a highly efficient adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0053] S1. Preparation of porous biochar: 100g of biomass powder was added to 100g of 0.5mol / L phosphoric acid solution and stirred at 75℃ for 1.5h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain pretreated biomass powder. 80g of pretreated biomass powder was mixed with 144g of sodium bicarbonate and calcined under a nitrogen atmosphere at 400℃ for 1h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0054] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 300g of ethanol aqueous solution (ethanol to water volume ratio of 1:3), and then 4.8g of γ-mercaptopropyltrioxysilane was added. The mixture was ball-milled at 200rpm for 30min at room temperature, with the milling direction changed every 20min. Then it was ball-milled at 400rpm for 15min, with the milling direction changed every 10min. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0055] S3. Preparation of modified porous biochar: 45g of mercapto-modified porous biochar was added to 700g of deionized water, followed by the addition of 7g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 0.5g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 5ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 10mW / cm². 2 The mixture was reacted at a constant temperature of 80℃ for 5 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0056] S4. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 60g of polydimethyldiallylammonium chloride and 1g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 1g of chitosan was dissolved in 40ml of 0.1M hydrochloric acid solution. The mixture was reacted at 55℃ for 5h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 800g of deionized water, followed by 8g of 3-mercaptoisobutyrylglycine and 0.8ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 40℃ for 16h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0057] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S4 and 20g of modified bentonite from step S5 were added to 800g of deionized water and stirred evenly. Then, 10g of glutaraldehyde, 15g of hydroxypropyl-β-cyclodextrin and 35g of triethylamine were added. The mixture was reacted at 75°C under a nitrogen atmosphere for 6 hours. 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 high-efficiency adsorbent material.

[0058] Example 4

[0059] This embodiment provides a highly efficient adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0060] S1. Preparation of porous biochar: 100g of rice straw powder was added to 2000g of 1.0mol / L phosphoric acid solution and stirred at 85℃ for 2.5h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain phosphoric acid pretreated biomass powder. 80g of pretreated biomass powder was mixed with 176g of sodium bicarbonate and calcined under a nitrogen atmosphere at 600℃ for 2h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0061] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 900g of ethanol-water solution (ethanol to water volume ratio of 1:4), and then 7.2g of γ-mercaptopropyltrioxysilane was added. The mixture was ball-milled at 300rpm for 60min at room temperature, with the milling direction changed every 20min. Then, it was ball-milled at 500rpm for 40min, with the milling direction changed every 10min. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0062] S3. Preparation of modified porous biochar: 60g of mercapto-modified porous biochar was added to 800g of deionized water, followed by the addition of 11g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 1g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 10ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 20mW / cm². 2 The mixture was reacted at a constant temperature of 85℃ for 8 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0063] S4. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 100g of polydimethyldiallylammonium chloride and 6g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 6g of chitosan was dissolved in 60ml of 0.1M hydrochloric acid solution. The mixture was reacted at 65℃ for 7h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 1000g of deionized water, followed by 24g of 3-mercaptoisobutyrylglycine and 8ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 40℃ for 18h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0064] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S4 and 30g of modified bentonite from step S5 were added to 1000g 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 85°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.

[0065] Comparative Example 1

[0066] This comparative example provides an adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0067] S1. Preparation of porous biochar: 100g of corn stalk powder was added to 1000g of 0.8mol / L phosphoric acid solution and stirred at 80℃ for 2h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain phosphoric acid pretreated biomass powder. 80g of pretreated biomass powder was mixed with 160g of sodium bicarbonate and calcined at 500℃ under a nitrogen atmosphere for 1h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0068] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 600g of ethanol aqueous solution (ethanol to water volume ratio of 1:3.5), and then 6g of γ-mercaptopropyltrioxysilane was added. The mixture was ball-milled at 250rpm for 45min at room temperature, with the milling direction changed every 20min. Then it was ball-milled at 450rpm for 30min, with the milling direction changed every 10min. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0069] S3. Preparation of modified porous biochar: 50g of mercapto-modified porous biochar was added to 750g of deionized water, followed by the addition of 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 0.8g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 8ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 15mW / cm². 2 The mixture was reacted at a constant temperature of 85℃ for 6 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0070] S4. Preparation of adsorbent material: 50g of modified porous biochar and 25g of bentonite from step S4 were added to 1000g 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 80°C under a nitrogen atmosphere for 8 hours. 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 2

[0072] This comparative example provides an adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0073] S1. Preparation of porous biochar: 100g of corn stalk powder was added to 1000g of 0.8mol / L phosphoric acid solution and stirred at 80℃ for 2h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain phosphoric acid pretreated biomass powder. 80g of pretreated biomass powder was mixed with 160g of sodium bicarbonate and calcined at 500℃ under a nitrogen atmosphere for 1h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0074] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 600g of ethanol aqueous solution (ethanol to water volume ratio of 1:3.5), and then 6g of γ-mercaptopropyltrioxysilane was added. The mixture was ball-milled at 250rpm for 45min at room temperature, with the milling direction changed every 20min. Then it was ball-milled at 450rpm for 30min, with the milling direction changed every 10min. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0075] S3. Preparation of modified porous biochar: 50g of mercapto-modified porous biochar was added to 750g of deionized water, followed by the addition of 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 0.8g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 8ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 15mW / cm². 2 The mixture was reacted at a constant temperature of 85℃ for 6 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0076] S4. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 80g of polydimethyldiallylammonium chloride and 4g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 4g of chitosan was dissolved in 40ml of 0.1M hydrochloric acid solution. The mixture was reacted at 60℃ for 6h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 800g of deionized water, followed by 16g of 3-mercaptoisobutyrylglycine and 5ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 40℃ for 16h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0077] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S4 and 25g of modified bentonite from step S5 are added to 1000g of deionized water, stirred evenly, filtered, washed 3 times with anhydrous ethanol, and dried at 80℃ for 3h to obtain the adsorbent material.

[0078] Comparative Example 3

[0079] This embodiment provides a highly efficient adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0080] S1. Preparation of porous biochar: 100g of corn stalk powder was added to 1000g of 0.8mol / L phosphoric acid solution and stirred at 80℃ for 2h. After treatment, the mixture was filtered, washed three times with deionized water, and dried at 80℃ for 3h to obtain phosphoric acid pretreated biomass powder. 80g of pretreated biomass powder was mixed with 160g of sodium bicarbonate and calcined at 500℃ under a nitrogen atmosphere for 1h. After calcination, the mixture was cooled to room temperature and dried to obtain porous biochar.

[0081] S2. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 80g of polydimethyldiallylammonium chloride and 4g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 4g of chitosan was dissolved in 40ml of 0.1M hydrochloric acid solution. The mixture was reacted at 60℃ for 6h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 800g of deionized water, followed by 16g of 3-mercaptoisobutyrylglycine and 5ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 40℃ for 16h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0082] S3. Preparation of adsorbent material: 50g of porous biochar from step S4 and 25g of modified bentonite from step S5 were added to 1000g 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 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 high-efficiency adsorbent material.

[0083] Comparative Example 4

[0084] This comparative example provides an adsorbent material for treating wastewater and its preparation method, specifically including the following steps:

[0085] S1. Preparation of porous biochar: 100g 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.

[0086] S2. Preparation of thiolized porous biochar: 60g of porous biochar was added to 600g of ethanol aqueous solution (volume ratio of ethanol to water was 1:3.5), and then 6g of γ-mercaptopropyltrioxysilane was added. The mixture was stirred at 50℃ for 3h. After the reaction was completed, the mixture was filtered, washed three times with anhydrous ethanol, and dried at 80℃ for 3h to obtain thiolized porous biochar.

[0087] S3. Preparation of modified porous biochar: 50g of mercapto-modified porous biochar was added to 750g of deionized water, followed by the addition of 10g of sodium 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone (i.e., 0.8g of 2,2-dimethoxy-2-phenylethyl ketone dissolved in 8ml of ethanol). The reaction was carried out under constant temperature and ultraviolet light with an intensity of 15mW / cm². 2 The mixture was reacted at a constant temperature of 85℃ for 6 hours. After the reaction was completed, it was filtered, washed three times with deionized water, and dried at 80℃ for 4 hours to obtain modified porous biochar.

[0088] S4. Preparation of modified bentonite: 100g of pulverized bentonite was added to a mixture of 80g of polydimethyldiallylammonium chloride and 4g of chitosan, maintaining a water-to-bentonite mass ratio of 10:1. 4g of chitosan was dissolved in 40ml of 0.1M hydrochloric acid solution. The mixture was reacted at 60℃ for 6h. After the reaction was completed, the mixture was filtered, washed with distilled water, and dried at 60℃ to obtain composite bentonite. Then, 80g of composite bentonite was added to 800g of deionized water, followed by 16g of 3-mercaptoisobutyrylglycine and 5ml of concentrated sulfuric acid. The mixture was reacted in a water bath at 40℃ for 16h. After the reaction was completed, the mixture was filtered, washed with distilled water and ethanol, and dried under vacuum at 35℃ to obtain modified bentonite, which was then pulverized and passed through a 100-mesh sieve.

[0089] S5. Preparation of adsorbent material: 50g of modified porous biochar from step S4 and 25g of modified bentonite from step S5 were added to 1000g 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 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 1-4 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+ Cr 2+ Pb 2+The concentrations of all pollutants were 300 mg / L, and the concentrations of phenol and aniline were 100 mg / L. Eight 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 1-4 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] Table 1 shows that, comparing Examples 1-4, the adsorbent materials prepared by this invention all possess good adsorption capacity for heavy metal ions and organic pollutants, and can simultaneously adsorb heavy metal ions and organic pollutants in wastewater, demonstrating promising application prospects. Comparing Comparative Example 1 with Example 1, modification of bentonite enhances its adsorption capacity for metal ions, thereby improving the adsorption efficiency of the adsorbent material. Comparative Example 2 with Example 1 shows that the synergistic effect between cyclodextrin, modified porous biochar, and modified bentonite can further improve the adsorption capacity of the adsorbent material. Comparative Example 3 with Example 1 shows that modification of porous biochar and the introduction of sulfonic acid groups can improve the adsorption capacity of the adsorbent material. Comparative Example 4 with Example 1 shows that the synergistic effect of phosphoric acid pretreatment, sodium bicarbonate calcination, and wet ball milling for thiolation of biochar is beneficial to improving the adsorption capacity of the modified porous biochar.

[0094] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for the preparation of a high efficiency adsorbent material for the treatment of wastewater, characterized by: Includes the following steps: S1. Preparation of porous biochar: Pretreated biomass powder is mixed with sodium bicarbonate and calcined under a nitrogen atmosphere. After calcination, it is cooled to room temperature, washed and dried to obtain porous biochar. S2. Preparation of thiolized porous biochar: Porous biochar was added to an aqueous ethanol solution, followed by the addition of γ-mercaptopropyltrioxysilane, and ball milling was performed. After the reaction was completed, the mixture was filtered, washed, and dried to obtain thiolized porous biochar. S3. Preparation of modified porous biochar: Thiolized porous biochar was added to deionized water, followed by the addition of sodium salt of 3-allyloxy-2-hydroxy-1-propanesulfonate and an ethanol solution of 2,2-dimethoxy-2-phenylethyl ketone. The reaction was carried out under ultraviolet light at a constant temperature. After the reaction was completed, the mixture was filtered, washed and dried to obtain modified porous biochar. S4. Preparation of modified bentonite: The pulverized bentonite was added to a mixture of polydimethyldiallylammonium chloride and chitosan and reacted at a constant temperature. After the reaction was completed, the mixture was filtered, washed, and dried to obtain composite bentonite. Then, the composite bentonite, 3-mercaptoisobutyrylglycine, and concentrated sulfuric acid were mixed and reacted in a water bath. After the reaction was completed, the mixture was filtered, washed, and dried to obtain modified bentonite. S5. Preparation of adsorbent material: The modified porous biochar from step S3 and the modified bentonite 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 high-efficiency adsorbent material.

2. A method of preparing a high efficiency adsorbent material for treating wastewater as claimed in claim 1, characterized by: The pretreatment method of biomass powder in step S1 includes: adding biomass powder to phosphoric acid solution, stirring, filtering, washing and drying after treatment to obtain biomass powder pretreated with phosphoric acid.

3. A method of preparing a high efficiency adsorbent material for treating wastewater as claimed in claim 2, wherein: The biomass powder includes one or more of corn straw powder, rice straw powder, sorghum straw powder, and wheat straw powder. The stirring temperature is 75-85℃, and the stirring time is 1.5-2.5h. The concentration of the phosphoric acid solution is 0.5-1.0mol / L, and the mass ratio of the biomass powder to the phosphoric acid solution is 1:2-1:

20.

4. The method for preparing a high-efficiency adsorbent material for wastewater treatment as described in claim 1, characterized in that: In step S1, the mass ratio of pretreated biomass powder to sodium bicarbonate is 1:1.8-2.2, the calcination temperature is 400-600℃, and the time is 1-2h.

5. The method for preparing a high-efficiency adsorbent material for wastewater treatment as described in claim 1, characterized in that: In step S2, porous biochar is placed in a ball mill jar, and an aqueous ethanol solution and γ-mercaptopropyltrioxysilane are added. The ball milling reaction is carried out at room temperature. First, the ball milling is carried out at a speed of 200-300 rpm for 0.5-1 h, and the milling direction is changed every 20 min. Then, the ball milling is carried out at a speed of 400-500 rpm for 15-40 min, and the milling direction is changed every 10 min.

6. The method for preparing a high-efficiency adsorbent material for wastewater treatment as described in claim 1, characterized in that: In step S2, the mass ratio of the porous biochar, the aqueous ethanol solution, and γ-mercaptopropyltrioxysilane is 1:5-15:0.08-0.

12.

7. The method for preparing a high-efficiency adsorbent material for wastewater treatment as described in claim 1, characterized in that: In step S3, the mass ratio of thiolated porous biochar, deionized water, sodium 3-allyloxy-2-hydroxy-1-propanesulfonate, and 2,2-dimethoxy-2-phenylethyl ketone is 45-60:700-800:7-11:0.5-1.

8. The method for preparing a high-efficiency adsorbent material for wastewater treatment as described in claim 1, characterized in that: In step S4, the mass ratio of bentonite, polydiallyl ammonium chloride and chitosan is 1:0.6-1:0.01-0.06, and the mass-volume ratio of composite bentonite, 3-mercaptoisobutyrylglycine and concentrated sulfuric acid is 1:0.1-0.3:0.01-0.

1.

9. The method for preparing a high-efficiency adsorbent material for wastewater treatment as described in claim 1, characterized in that: In step S5, the mass ratio of modified porous biochar, modified bentonite, glutaraldehyde, hydroxypropyl-β-cyclodextrin, and triethylamine is 1:0.4-0.6:0.2-0.4:0.3-0.5:0.7-1, the heating temperature is 75-85℃, and the time is 6-10h.

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

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