CN106179249A - A kind of preparation method of attapulgite cellulose composite adsorption microsphere - Google Patents

Abstract

The invention discloses a preparation method of attapulgite cellulose composite adsorption microspheres. The method comprises the following three steps: pretreatment and surface modification of attapulgite; preparation of ionic liquid cellulose solution; attapulgite cellulose composite adsorption microspheres. Preparation of balls. The preparation process is simple and convenient, the ionic liquid solvent used is safe and non-toxic, the prepared attapulgite cellulose microspheres are porous, have good dispersibility, biocompatibility and thermal stability, and have strong adsorption capacity for pollutants in water, large adsorption capacity, It has the advantages of high removal efficiency, stable properties, and easy recovery; it solves the problems of poor adsorption capacity of attapulgite, difficult recovery, weak mechanical strength of cellulose adsorbent, and low thermal stability. Pollution, making full use of cellulose and attapulgite renewable resources, high practical value, can be used for advanced treatment of pollutants in water, and solves the problems of energy crisis and environmental pollution.

Description

A kind of preparation method of attapulgite cellulose composite adsorption microsphere

Technical field:

The invention relates to the field of sewage treatment, in particular to a preparation method of attapulgite cellulose composite adsorption microspheres.

Background technique:

With the rapid development of modern society, environmental pollution caused by industrial wastewater and domestic sewage has seriously damaged the ecological environment. How to treat pollutants in sewage economically and efficiently has become one of the urgent tasks of environmental protection and chemical industry.

The attapulgite has a unique layer chain crystal structure and nano-scale fibrous crystal form, developed internal pores and large specific surface area, which endow the attapulgite with strong adsorption performance and ion exchange performance. It has a strong adsorption effect on heavy metal ions in wastewater and organic pollutants in water, such as benzene compounds, phenol compounds, crude oil and petroleum products. In addition, the attapulgite itself is non-toxic, harmless, with high storage capacity in nature and low cost. It has the advantages of simple process operation, high adsorption efficiency, no pollution and less secondary pollution in the water treatment process, so that the attapulgite can be used in industrial sewage and The treatment of domestic sewage shows excellent application potential. However, attapulgite is a kind of natural clay. When attapulgite is used in wastewater, when water and organic pollutants compete for adsorption on the surface of attapulgite, water molecules are preferentially adsorbed, occupying active sites on the surface of attapulgite pores, making it The low removal rate of organic pollutants limits its application in the field of adsorption. In addition, due to its high surface energy, the attapulgite is easy to aggregate into agglomerates, and the specific surface area of the aggregated attapulgite is reduced, thereby limiting its adsorption capacity, and its powder form also has problems in recycling after use. A certain degree of difficulty.

Cellulose is the most abundant renewable resource in nature. It is a natural polysaccharide molecule, non-toxic, biodegradable, strong water resistance, highly hydrophilic, good biocompatibility, suitable porous structure, extremely Low non-specific adsorption performance. Its macromolecular chain contains many amino groups and hydroxyl groups. It has adsorption and flocculation effects on metal ions and polar organic compounds. It is a good adsorbent matrix material. Adsorbents prepared from cellulose are widely used in the enrichment and separation of various metal ions, the separation and purification of proteins, and the removal of dyes in wastewater; however, due to the strong hydrogen bonding between natural cellulose molecules, a very dense structure is formed , resulting in difficulties in the processing of cellulose materials, and the cellulose adsorbent has problems such as weak mechanical strength and low thermal stability.

Invention content:

The purpose of the present invention is to provide a preparation method of attapulgite cellulose composite adsorption microspheres, the preparation process is simple and convenient, the ionic liquid solvent used is safe and non-toxic, and the prepared attapulgite cellulose microspheres are porous, dispersible and biocompatible Good thermal stability, strong adsorption capacity, large adsorption capacity, high removal efficiency, stable properties, and easy recovery of pollutants in water; it solves the problem of poor adsorption capacity of attapulgite, difficult recovery, and weak mechanical strength of cellulose adsorbent , low thermal stability, etc. At the same time, there are wide sources of raw materials, low prices, no secondary pollution, full use of cellulose and attapulgite regeneration resources, high practical value, and can be used for advanced treatment of water pollutants, solving the energy crisis and Environmental Pollution.

The present invention is achieved through the following technical solutions:

A preparation method of attapulgite cellulose composite adsorption microspheres, the method comprising the following three steps:

a. Pretreatment and surface modification of attapulgite: the powder attapulgite is soaked in dilute hydrochloric acid with a mass fraction of 5-10% for 8-12 hours, washed to neutrality, and dispersed into a mixture of ethanol and water with a volume ratio of 9:1 Add a silane coupling agent to the solution, and then adsorb after ultrasonication at 40-50°C for 50 minutes. After separation and purification, the adsorbed product is dried at 110°C to obtain silane-modified attapulgite, which is ground for later use; the powder attapulgite and silane coupling The mass ratio of the joint agent is 4:1～6:1;

b. Preparation of ionic liquid cellulose solution: add 2 to 6 parts by weight of cellulose to 100 parts by weight of ionic liquid, stir and mix at 90 to 110° C. until the cellulose is completely dissolved, and obtain an ionic liquid cellulose solution;

c. Preparation of attapulgite cellulose composite adsorption microspheres: add the silane-modified attapulgite obtained in step a to the ionic liquid cellulose solution obtained in step b, and the mass of the silane-modified attapulgite is the mass of the ionic liquid cellulose solution 0.2-0.4 times of 0.2-0.4 times, 90-100 ℃, 80-200rpm rotating speed, after stirring for 20-30 minutes, add oil phase and surfactant, the volume ratio of oil phase and ionic liquid cellulose solution is 4:1-6:1, The mass ratio of the surfactant to the oil phase is 1:40-1:100, stirred for 15-20 minutes to form a reverse-phase suspension system, cooled to 30-50°C through a program, and a curing agent is added, the volume of which is ionic liquid 2 to 3 times the volume of the cellulose solution, and keep stirring for 20 minutes to form attapulgite cellulose composite adsorption microspheres; wash with deionized water, soak, and sieve in a wet state to obtain attapulgite cellulose composite adsorption microspheres.

The temperature programming refers to the rate of cooling by 5°C every 10 minutes.

The preparation method of the attapulgite cellulose composite adsorption microspheres specifically comprises the following steps:

a. The attapulgite is extruded, sheared, and pulverized to obtain a powder with a particle size of 200 mesh, soaked in dilute hydrochloric acid with a mass fraction of 5-10% for 8-12 hours, washed with deionized water and precipitated to neutral, and dispersed in ethanol and In a mixed solution with a water volume ratio of 9:1, add a silane coupling agent during stirring, ultrasonicate at 40-50°C for 50 minutes, stir and adsorb at 50°C for 4 hours, and the adsorbed product is separated by suction filtration and then washed with toluene, absolute ethanol and Washing with deionized water to remove excess silane coupling agent, drying at 110°C to obtain silane-modified attapulgite, which is ground for later use; the mass ratio of the powder attapulgite to the silane coupling agent is 4:1 to 6: 1;

b. Preparation of ionic liquid cellulose solution: add 2 to 6 parts by weight of cellulose to 100 parts by weight of ionic liquid, stir and mix at 90 to 110 ° C until the cellulose is completely dissolved, and the stirring speed is 80 to 200 rpm to obtain an ionic liquid Cellulose solution;

c. Preparation of attapulgite cellulose composite adsorption microspheres: add the silane-modified attapulgite obtained in step a to the ionic liquid cellulose solution obtained in step b, and the mass of the silane-modified attapulgite is the mass of the ionic liquid cellulose solution 0.2-0.4 times of 0.2-0.4 times, 90-100 ℃, 80-200rpm rotating speed, after stirring for 20-30 minutes, add oil phase and surfactant, the volume ratio of oil phase and ionic liquid cellulose solution is 4:1-6:1, The mass ratio of surfactant to oil phase is 1:40~1:100, stir at 300~500rpm for 15~20 minutes to form a reverse phase suspension system, and cool down to 30~50℃ at a rate of 5℃ every 10min , the cellulose solution coagulates into a ball; add a curing agent, the volume of the curing agent is 2 to 3 times the volume of the ionic liquid cellulose solution; after 5 minutes, the speed is reduced to 200rpm, keep stirring for 20 minutes, the cellulose solution solidifies rapidly, forming unevenness Rod cellulose composite adsorption microspheres, after cooling down to room temperature, filter the attapulgite rod cellulose composite adsorption microspheres from the reaction solution, wash with deionized water, and then soak the microspheres in deionized water for 48 hours; wet sieve The attapulgite cellulose composite adsorption microspheres were obtained.

In step a, the silane coupling agent is selected from γ-(2,3-glycidoxy)propyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane , One of vinyltrimethoxysilane.

In step a, after the attapulgite powder with a particle size of 200 mesh is soaked in dilute hydrochloric acid with a mass fraction of 5-10% for 8-12 hours, the attapulgite is activated into a fluffy sol-like form, washed to neutrality and then coupled with silane The attapulgite surface is modified from completely hydrophilic to moderately lipophilic, which enhances the dispersion in organic solvents, reduces the agglomeration of the attapulgite, and facilitates the competitive adsorption of organic pollutants on the attapulgite surface.

In step b, the ionic liquid is 1-butyl-3-methylimidazolium chloride or 1-allyl-3-methylimidazolium acetate; the cellulose is selected from pulp, absorbent cotton, refined One of cotton or microcrystalline cellulose.

Natural cellulose has the structural characteristics of high crystallinity and a large number of hydrogen bonds between molecules and inside molecules, making it difficult to dissolve in water and common organic solvents. Ionic liquid is a new type of green solvent for cellulose, which can effectively destroy the crystal structure of cellulose and reduce its crystallinity. It can not only effectively dissolve cellulose, but also provide a good reaction environment for cellulose.

In step c, the surfactant is Tween 80, Span 85 or a mixture thereof; the oil phase is pump oil, mineral oil, paraffin oil or peanut oil; the curing agent is water, ethanol, acetone or its mixture.

The beneficial effects of the present invention are as follows:

(1) The present invention uses an ion solution as a solvent to directly dissolve cellulose, and the process is simple, non-toxic, less polluting to the environment, and can be recycled again.

(2) The surface of the attapulgite is modified by a silane coupling agent, so that the surface polarity of the attapulgite is reduced, the surface property is changed from completely hydrophilic to moderately lipophilic, the dispersion in organic solvents is enhanced, and the attapulgite is reduced. The agglomeration phenomenon is conducive to the competitive adsorption of organic pollutants on the surface of the attapulgite.

(3) The present invention couples two adsorption materials of modified attapulgite and ionic liquid-dissolved cellulose to produce a synergistic effect, enhance the compatibility between attapulgite and organic cellulose molecules, and improve the binding force of the molecular interface, It promotes the formation of cellulose microspheres and effectively improves the adsorption performance; in addition, the network structure of regenerated cellulose embedded in the attapulgite components effectively improves the mechanical strength and thermal stability of the microspheres; at the same time, the cellulose provides good support for the attapulgite The carrier function of the attapulgite further avoids the aggregation of the attapulgite, which is beneficial to the recovery of the attapulgite adsorbent.

(4) Attapulgite is non-toxic, harmless, with high storage capacity and low cost; cellulose widely exists in green plants and is the most abundant renewable resource in nature. Making full use of attapulgite and cellulose is not only in line with "green chemistry" It can also solve the impact of environmental pollution. Through the compatibility of cellulose and attapulgite and other matrix materials, an adsorption material with both porous structure and strong pollutant adsorption capacity is formed, so that the obtained adsorbent has the advantages of strong adsorption capacity, large adsorption capacity, and high removal efficiency. Stable and easy to recycle and reuse.

In a word, the preparation process of the present invention is simple and convenient, the ionic liquid solvent used is safe and non-toxic, and the modified attapulgite and the cellulose dissolved in the ionic liquid are coupled to produce a synergistic effect, and the prepared attapulgite cellulose microspheres are porous, It has good dispersibility, biocompatibility and thermal stability, and has the advantages of strong adsorption capacity, large adsorption capacity, high removal efficiency, stable properties, and easy recovery of pollutants in water; it solves the problem of poor adsorption capacity of attapulgite, difficult recovery, fiber At the same time, the source of raw materials is wide, the price is low, no secondary pollution occurs, and the regeneration resources of cellulose and attapulgite are fully utilized, which has high practical value and can be used for advanced treatment of pollutants in water , to solve the energy crisis and environmental pollution problems.

detailed description:

The following is a further description of the present invention, rather than a limitation of the present invention.

Example 1:

The attapulgite is extruded, sheared, and crushed to obtain a powder with a particle size of 200 mesh. The powder is soaked in dilute hydrochloric acid with a mass fraction of 5% for 8 hours, then washed and precipitated with deionized water repeatedly to neutrality, and 20 g is dispersed in In the mixed solution of 100mL ethanol and water, wherein the volume ratio of ethanol and water is 9:1, then add 5g gamma-(2,3-glycidoxy) propyltrimethoxysilane coupling agent while stirring, at 40 Ultrasonic at 50°C for 50 minutes, then stirred and adsorbed at 50°C for 4 hours, the adsorbed product was separated by suction filtration, washed with 100ml of toluene, absolute ethanol and deionized water to remove excess silane coupling agent, and dried at 110°C to obtain silane Modified attapulgite, ground for later use.

Add 100 grams of 1-butyl-3-methyl-imidazolium chloride salt and 2 grams of pulp into the flask, and stir at 90° C. at 80 rpm until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution.

The above-mentioned modified attapulgite whose quality is 0.2 times the mass of the ionic liquid cellulose solution is dispersed in the ionic liquid cellulose solution, and after stirring for 20 minutes at 90° C. at 80 rpm, add the oil phase and surfactant (oil The phase is pump oil, the surfactant is Tween 80), the volume ratio of the oil phase to the ionic liquid cellulose solution is 4:1, the mass ratio of the surfactant to the oil phase is 1:40, and stirred at 300rpm for 15 Minutes, form a reverse suspension system, cool down to 30°C at a rate of 5°C every 10 minutes, and the cellulose solution coagulates into balls; add a curing agent (the curing agent is water, and the volume is twice the volume of the ionic liquid cellulose solution) , after 5 minutes, the rotation speed was reduced to 200rpm, and kept stirring for 20 minutes, the cellulose solution solidified rapidly, forming attapulgite cellulose composite adsorption microspheres, the temperature was lowered to room temperature, and the microspheres were filtered out from the reaction solution, and washed with 1 to 2 times volume of deionized water for 3 to 6 times, and then soak the attapulgite cellulose composite adsorption microspheres in deionized water for 48 hours; sieve the attapulgite cellulose composite adsorption microspheres in a wet state to obtain the attapulgite cellulose composite adsorption Microspheres.

Example 2:

The attapulgite is extruded, sheared, and crushed to obtain a powder with a particle size of 200 mesh. The powder is soaked in dilute hydrochloric acid with a mass fraction of 10% for 12 hours, then washed and precipitated with deionized water repeatedly until neutral, and 20 g is dispersed in In a mixed solution of 100mL ethanol and water, wherein the volume ratio of ethanol and water is 9:1, then add 4g of N-2(aminoethyl)3-aminopropyltrimethoxysilane coupling agent while stirring, at 50℃ Ultrasonic for 50min, then stirred and adsorbed at 50°C for 4h, the adsorbed product was separated by suction filtration, washed with 100ml of toluene, absolute ethanol and deionized water to remove excess silane coupling agent, and dried at 110°C to obtain silane-modified Sexual attapulgite, ground for later use.

Add 100 grams of 1-allyl-3-methylimidazole acetate and 6 grams of absorbent cotton into the flask, and stir at 100° C. at 200 rpm until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution.

The above-mentioned modified attapulgite whose quality is 0.4 times the mass of the ionic liquid cellulose solution is dispersed into the ionic liquid cellulose solution, and after stirring for 30 minutes at 100° C. at 200 rpm, add the oil phase and surfactant (oil Phase is mineral oil, surfactant is Span 85), the volume ratio of oil phase and ionic liquid cellulose solution is 6: 1, the mass ratio of surfactant and oil phase is 1: 100, stir 20 minutes under 500rpm rotating speed , forming a reverse suspension system, cooling down to 50°C at a rate of 5°C every 10 minutes, the cellulose solution coagulates into balls; adding a curing agent (the curing agent is ethanol, and the volume is 3 times the volume of the ionic liquid cellulose solution), After 5 minutes, the rotation speed was reduced to 200rpm, and kept stirring for 20 minutes. The cellulose solution solidified rapidly and formed attapulgite cellulose composite adsorption microspheres. Wash with deionized water for 3 to 6 times, then soak the attapulgite cellulose composite adsorption microspheres in deionized water for 48 hours; sieve the attapulgite cellulose composite adsorption microspheres in a wet state to obtain the attapulgite cellulose composite adsorption microspheres ball.

Example 3:

The attapulgite is extruded, sheared, and crushed to obtain a powder with a particle size of 200 mesh. The powder is soaked in dilute hydrochloric acid with a mass fraction of 8% for 10 hours, then washed and precipitated with deionized water repeatedly to neutrality, and 20 g is dispersed in Into a mixed solution of 100mL ethanol and water, wherein the volume ratio of ethanol and water is 9:1, then add 3.3g of vinyltrimethoxysilane coupling agent while stirring, ultrasonicate at 50°C for 50min, then stir and adsorb at 50°C After 4 hours, the adsorption product was separated by suction filtration, washed with 100ml of toluene, absolute ethanol and deionized water to remove excess silane coupling agent, and dried at 110°C to obtain silane-modified attapulgite, which was ground for later use.

Add 100 grams of 1-allyl-3-methylimidazole acetate and 5 grams of refined cotton into the flask, and stir at 100° C. at 150 rpm until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution.

The above-mentioned modified attapulgite whose quality is 0.3 times the mass of the ionic liquid cellulose solution is dispersed in the ionic liquid cellulose solution, and after stirring for 25 minutes at 95° C. at 150 rpm, add the oil phase and surfactant (oil The phase is paraffin oil, the surfactant is Span 85), the volume ratio of the oil phase to the ionic liquid cellulose solution is 5:1, the mass ratio of the surfactant to the oil phase is 1:60, and stirred for 20 minutes at 400 rpm , forming a reverse suspension system, cooling down to 40°C at a rate of 5°C per 10 minutes, the cellulose solution coagulates into balls; adding a curing agent (the curing agent is acetone, and the volume is 3 times the volume of the ionic liquid cellulose solution), After 5 minutes, the rotation speed was reduced to 200rpm, and kept stirring for 20 minutes. The cellulose solution solidified rapidly and formed attapulgite cellulose composite adsorption microspheres. Wash with deionized water for 3 to 6 times, then soak the attapulgite cellulose composite adsorption microspheres in deionized water for 48 hours; sieve the attapulgite cellulose composite adsorption microspheres in a wet state to obtain the attapulgite cellulose composite adsorption microspheres ball.

Example 4:

The attapulgite is extruded, sheared, and crushed to obtain a powder with a particle size of 200 mesh. The powder is soaked in dilute hydrochloric acid with a mass fraction of 7% for 11 hours, and then washed and precipitated with deionized water repeatedly to neutrality. Take 20g and disperse it in In the mixed solution of 100mL ethanol and water, wherein ethanol and water volume ratio are 9:1, then add 4.4g N-2 (aminoethyl) 3-aminopropyltrimethoxysilane coupling agent while stirring, at 45 Ultrasonic at 50°C for 50 minutes, then stirred and adsorbed at 50°C for 4 hours, the adsorbed product was separated by suction filtration, washed with 100ml of toluene, absolute ethanol and deionized water to remove excess silane coupling agent, and dried at 110°C to obtain silane Modified attapulgite, ground for later use.

Add 100 grams of 1-butyl-3-methylimidazolium chloride salt and 4 grams of microcrystalline cellulose into the flask, and stir at 100° C. at 100 rpm until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution.

The above-mentioned modified attapulgite whose quality is 0.4 times the mass of the ionic liquid cellulose solution is dispersed in the ionic liquid cellulose solution, and after stirring for 25 minutes at 95° C. at 180 rpm, add the oil phase and surfactant (oil Phase is peanut oil, surfactant is Tween 80), the volume ratio of oil phase and ionic liquid cellulose solution is 6: 1, the mass ratio of surfactant and oil phase is 1: 40, stirs 20 minutes under 450rpm rotating speed , form a reverse suspension system, cool down to 30°C at a rate of 5°C per 10 minutes, and the cellulose solution coagulates into balls; add a solidifying agent whose volume is 3 times the volume of the ionic liquid cellulose solution (the solidifying agent has a volume ratio of 1:3 mixture of ethanol and acetone), after 5 minutes, the rotation speed was reduced to 200rpm, and kept stirring for 20 minutes, the cellulose solution solidified rapidly, forming attapulgite cellulose composite adsorption microspheres, the temperature was lowered to room temperature, and the microspheres were removed from the reaction solution Filter out the medium, wash with 1 to 2 times the volume of deionized water for 3 to 6 times, then soak the attapulgite cellulose composite adsorption microspheres in deionized water for 48 hours; sieve the attapulgite cellulose composite adsorption microspheres wet The attapulgite cellulose composite adsorption microspheres were obtained.

Example 5:

The attapulgite is extruded, sheared, and crushed to obtain a powder with a particle size of 200 mesh. The powder is soaked in dilute hydrochloric acid with a mass fraction of 6% for 9 hours, then washed and precipitated with deionized water repeatedly to neutrality, and 20 g is dispersed in 100mL of ethanol and water mixed solution, wherein the volume ratio of ethanol and water is 9:1, then add 5g of vinyltrimethoxysilane coupling agent while stirring, ultrasonic at 45°C for 50min, then stir and adsorb at 50°C for 4h , the adsorption product was separated by suction filtration, washed with 100ml of toluene, absolute ethanol and deionized water to remove excess silane coupling agent, and dried at 110°C to obtain silane-modified attapulgite, which was ground for later use.

Add 100 grams of 1-allyl-3-methylimidazole acetate and 5 grams of microcrystalline cellulose into the flask, and stir at 100° C. at 150 rpm until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution.

The above-mentioned modified attapulgite whose quality is 0.3 times the mass of the ionic liquid cellulose solution is dispersed in the ionic liquid cellulose solution, and after stirring for 20 minutes at 100° C. at a speed of 150 rpm, an oil phase and a surfactant (oil The phase is peanut oil, the surfactant is a mixture of Tween 80 and Span 85 with a mass ratio of 1:1), the volume ratio of the oil phase to the ionic liquid cellulose solution is 5:1, and the mass ratio of the surfactant to the oil phase 1:60, stirred at 400 rpm for 20 minutes to form a reverse-phase suspension system, cooled to 30°C at a rate of 5°C every 10 minutes, and the cellulose solution coagulated into balls; the volume of the ionic liquid cellulose solution added was 3 times the curing agent (the curing agent is a mixture of ethanol and acetone with a volume ratio of 1:1), reduce the speed to 200rpm after 5 minutes, keep stirring for 20 minutes, the cellulose solution is rapidly solidified, and attapulgite cellulose composite adsorption microspheres are formed , the temperature is lowered to room temperature, the microspheres are filtered out from the reaction solution, washed with 1 to 2 times the volume of deionized water for 3 to 6 times, and then the attapulgite cellulose composite adsorption microspheres are soaked in deionized water for 48 hours; The attapulgite cellulose composite adsorption microspheres are sieved in a wet state to obtain the attapulgite cellulose composite adsorption microspheres.

Embodiment 6:

The attapulgite is extruded, sheared, and crushed to obtain a powder with a particle size of 200 mesh. The powder is soaked in dilute hydrochloric acid with a mass fraction of 8% for 10 hours, then washed and precipitated with deionized water repeatedly to neutrality, and 20 g is dispersed in In the mixed solution of 100mL ethanol and water, wherein the volume ratio of ethanol and water is 9:1, then add 5g gamma-(2,3-glycidoxy) propyltrimethoxysilane coupling agent while stirring, at 50 Ultrasonic at 50°C for 50 minutes, then stirred and adsorbed at 50°C for 4 hours, the adsorbed product was separated by suction filtration, washed with 100ml of toluene, absolute ethanol and deionized water to remove excess silane coupling agent, and dried at 110°C to obtain silane Modified attapulgite, ground for later use.

Add 100 grams of 1-butyl-3-methylimidazolium chloride salt and 5 grams of microcrystalline cellulose into the flask, and stir at 100° C. at 180 rpm until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution.

The above-mentioned modified attapulgite whose quality is 0.3 times the mass of the ionic liquid cellulose solution is dispersed in the ionic liquid cellulose solution, and after stirring for 20 minutes at 100° C. at a speed of 180 rpm, add the oil phase and surfactant (oil The phase is paraffin oil, the surfactant is a mixture of Tween 80 and Span 85 with a mass ratio of 1:1), the volume ratio of the oil phase to the ionic liquid cellulose solution is 5:1, and the mass ratio of the surfactant to the oil phase The ratio is 1:80, stirred at 400rpm for 15 minutes to form a reverse suspension system, and the temperature is lowered to 30°C at a rate of 5°C every 10 minutes, and the cellulose solution is condensed into balls; the added volume is the volume of the ionic liquid cellulose solution 3 times the curing agent (the curing agent is a mixture of ethanol and water with a volume ratio of 1:1), the rotation speed is reduced to 200rpm after 5 minutes, and the stirring is kept for 20 minutes. The temperature is lowered to room temperature, the microspheres are filtered out from the reaction solution, washed with 1 to 2 times the volume of deionized water for 3 to 6 times, and then the attapulgite cellulose composite adsorption microspheres are soaked in deionized water for 48 hours and sieving the attapulgite cellulose composite adsorption microspheres in a wet state to obtain the attapulgite cellulose composite adsorption microspheres.

Example 7: Using the attapulgite cellulose composite adsorption microspheres prepared by the present invention for pollutant adsorption treatment:

The attapulgite cellulose composite adsorption microspheres, silane-modified attapulgite, natural unmodified attapulgite and natural unmodified cellulose prepared in Examples 1-6 were respectively used as adsorbents, and the initial concentration was 5 mg/L respectively. Phenol, catechol, hydroquinone, methylene blue, methyl orange, copper ions, cadmium ions, and lead ions are used as pollutants for adsorption treatment. The specific method is as follows:

Add adsorbent to the organic pollutants with an initial concentration of 5 mg/L, the solid-to-liquid ratio is 1 g:50 mL, oscillate at 25 °C at a constant temperature of 200 r/min for 12 h, filter the filtrate, and measure the adsorption amount. The results are shown in Table 1.

Table 1 Adsorption treatment of pollutants by different adsorbents

It can be seen from Table 1 that the attapulgite cellulose composite adsorption microspheres prepared in Examples 1-6, compared with silane-modified attapulgite, natural unmodified attapulgite, and natural unmodified cellulose, are less sensitive to phenolic dyes in water. The removal rate of methylene blue can be increased by more than 3-5 times; the highest removal rate of methylene blue in water is 97-99%; the removal rate of methyl orange has also reached more than 75%; the adsorption and removal of heavy metals also has a good effect , the removal rate is between 55-77%; while the removal rates of natural unmodified attapulgite and natural unmodified cellulose to pollutants are both above 35%. It can be seen from the above data that the attapulgite cellulose composite adsorption microspheres prepared by the present invention have good adsorption performance and good effect on pollutant removal.

In the invention, the modified attapulgite is compatible with cellulose to obtain an adsorption medium with a porous structure and a large specific surface area. By learning from each other, a synergistic effect is produced, and the ability to absorb and enrich pollutants is improved. The properties are stable and easy to recycle and reuse. ; At the same time, the source of raw materials is wide, the price is low, no secondary pollution occurs, the practical value is high, and it can be used for advanced treatment of pollutants in water.

Claims (5)

1. a preparation method of attapulgite cellulose composite adsorption microspheres, characterized in that the method comprises the following three steps: a. The powder attapulgite is soaked in dilute hydrochloric acid with a mass fraction of 5-10% for 8-12 hours, then washed to neutrality, dispersed into a mixed solution of ethanol and water with a volume ratio of 9:1, and a silane coupling agent is added, After ultrasonication for 50 minutes at 40-50°C, the adsorption product is separated and purified, and dried at 110°C to obtain silane-modified attapulgite, which is ground for later use; the mass ratio of the powder attapulgite to the silane coupling agent is 4:1～ 6:1; b. Add 2 to 6 parts by weight of cellulose to 100 parts by weight of the ionic liquid, stir and mix at 90 to 110° C. until the cellulose is completely dissolved to obtain an ionic liquid cellulose solution; c. Add the silane-modified attapulgite obtained in step a to the ionic liquid cellulose solution obtained in step b, the quality of the silane-modified attapulgite being 0.2-0.4 times the mass of the ionic liquid cellulose solution, at 90-100°C, After stirring at 80-200rpm for 20-30 minutes, add the oil phase and surfactant, the volume ratio of the oil phase to the ionic liquid cellulose solution is 4:1-6:1, and the mass ratio of the surfactant to the oil phase is 1 : 40 to 1: 100, stirred for 15 to 20 minutes to form a reversed phase suspension system, cooled to 30 to 50°C through programming, added a curing agent, the volume of the curing agent was 2 to 3 times the volume of the ionic liquid cellulose solution, and kept Stir for 20 minutes to form attapulgite cellulose composite adsorption microspheres; wash with deionized water, soak, and sieve in a wet state to obtain attapulgite cellulose composite adsorption microspheres. 2. The preparation method of the attapulgite cellulose composite adsorption microspheres according to claim 1, wherein the programmed cooling refers to the rate of cooling by 5° C. every 10 minutes. 3. the preparation method of attapulgite cellulose composite adsorption microsphere according to claim 1 is characterized in that, in step a, described silane coupling agent is selected from gamma-(2,3-glycidoxy propoxy ) Propyltrimethoxysilane, N-2 (aminoethyl) 3-aminopropyltrimethoxysilane, vinyltrimethoxysilane. 4. the preparation method of attapulgite cellulose composite adsorption microsphere according to claim 1 is characterized in that, in step b, described ionic liquid is 1-butyl-3-methylimidazolium chloride salt or 1- Allyl-3-methylimidazole acetate; the cellulose is selected from one of pulp, absorbent cotton, refined cotton or microcrystalline cellulose. 5. the preparation method of attapulgite cellulose composite adsorption microsphere according to claim 1 is characterized in that, in step c, described surfactant is Tween 80, Span 85 or its mixture; Described oil The phase is pump oil, mineral oil, paraffin oil or peanut oil; the curing agent is water, ethanol, acetone or a mixture thereof.