A method for preparing a tannery waste leather shavings-based biochar aerogel adsorption material

Abstract

The application discloses a kind of tannery waste leather scrap based biochar aerogel adsorption material preparation method, by introducing the cellulose structure of alfalfa, melamine and metal ions, the proportion of oxygen, nitrogen functional groups in composite biochar is increased. The adsorbent is activated by using plasma technology, the excess moisture of the obtained hydrogel is filtered out, vacuum freeze drying machine is used for precooling, the hydrogel is placed in cold trap for prefreezing, and then freeze drying is carried out under vacuum condition. The tannery waste leather scrap based biochar aerogel adsorption material for treating isoquinoline alkaloid wastewater can be obtained after drying. The application uses waste leather scrap and alfalfa as raw materials, uses dielectric barrier discharge plasma technology and vacuum freeze drying technology to prepare layered porous structure aerogel, can treat wastewater containing isoquinoline alkaloid and other polar adsorbates at room temperature, has strong adsorption capacity, and the aerogel is easy to recycle.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of adsorption material preparation, and particularly relates to a preparation method of a tannery waste leather crumb based biochar aerogel adsorption material, which helps to solve the pollution problem of isoquinoline alkaloid wastewater, so as to achieve the purpose of protecting human health and resource utilization of waste. BACKGROUND

[0002] Isoquinoline alkaloids, also known as benzyl isoquinoline alkaloids, are common alkaloids that have been used to synthesize a series of important drugs with anti-inflammatory, analgesic, anti-arrhythmic and antihypertensive effects. However, due to their wide use and discharge as an important pharmaceutical chemical intermediate, isoquinoline alkaloids have caused increasingly serious environmental pollution and ecological risk. The harm of isoquinoline alkaloids to the human body mainly includes the following points: 1. affecting the cardiovascular system: alkaloids can have direct or indirect toxic effects on the heart; 2. affecting the central nervous system: some alkaloids can affect the function of the nervous system, leading to central nervous system inhibition or excitation; 3. affecting the digestive system: after entering the digestive tract, alkaloids can stimulate the digestive tract tissue, causing symptoms such as nausea, vomiting, abdominal pain, and diarrhea. At present, various methods can be adopted to treat isoquinoline alkaloid wastewater, among which the adsorption method is widely concerned due to its easy treatment, low cost, and good effect. Polar adsorbents are easy to combine with polar adsorbates, and isoquinoline alkaloids in solution belong to polar adsorbates, so how to prepare an adsorbent with strong polarity, high stability and easy recovery has become the primary problem in the treatment of isoquinoline alkaloids by adsorption method.

[0003] Waste leather crumb is a waste leather sheet and waste material generated in the process of leather processing (such as trimming, cutting, polishing, etc.). The open-air disposal of waste leather crumb has the hazards of land occupation and environmental pollution, causing great burden to the environment. It is considered whether the waste leather crumb can be prepared into biochar and actually applied to water bodies or soil. Compared with other biomasses (straw, bamboo and walnut shell, etc.), the unique collagen fiber structure of waste leather crumb is relatively loose, and it contains a large amount of oxygen, nitrogen, sulfur and other functional groups, which can be used to prepare biochar at a lower pyrolysis temperature (300-500℃) and can be reused. However, due to the structural limitations of waste leather crumb biochar, the prepared biochar has low yield, small specific surface area and few active sites, and does not achieve the purpose of resource utilization. SUMMARY

[0004] The present application aims to overcome the shortcomings of the prior art and provide a tannery waste leather crumb based biochar aerogel adsorption material preparation method for deep treatment of isoquinoline alkaloid wastewater, which has strong adsorption capacity, good material functionality, high biochar yield, large specific surface area and active sites, ideal material aromaticity and polarity index, and is easy to recover.

[0005] To achieve the above object, the technical scheme adopted by the present application is:

[0006] A kind of preparation method of plant tanning leather waste skin scrap based biochar aerogel adsorption material, specific implementation steps are as follows:

[0007] (1) plant tanning leather waste skin scrap is cut into small pieces, after pickling, stirring at room temperature, washing to neutral (prevent other impurities pollution), drying;Then, the dried plant tanning leather waste skin scrap is put into a pulverizer for crushing, and sieving treatment is carried out for standby use;

[0008] (2) after stirring after pickling alfalfa, washing to neutral, drying, then the dried alfalfa is put into a pulverizer for crushing, and sieving treatment is carried out for standby use;

[0009] (3) the plant tanning leather waste skin scrap powder obtained in step (1), the alfalfa powder obtained in step (2) and melamine powder are mixed and stirred in MgCl2·6H2O solution, then dried, and then calcined and pyrolyzed under oxygen-limited conditions to obtain blended biochar powder;

[0010] (4) the blended biochar powder obtained in step (3) is cooled, ground and sieved;

[0011] (5) the biochar obtained in step (4) is loaded into a reaction tank and placed at the plasma jet nozzle for activation, and then dried to obtain a plant tanning leather waste skin scrap based biochar material;

[0012] (6) sodium alginate is dissolved in deionized water, and dispersed by ultrasonic stirring alternately, then the plant tanning leather waste skin scrap based biochar material obtained in step (5) is added to the sodium alginate solution for dispersion treatment;

[0013] (7) the solution obtained in step (6) is mixed with a calcium carbonate solution and dispersed;

[0014] (8) gluconolactone is added to the biochar mixed solution obtained in step (7) for mixing and stirring;

[0015] (9) the surface moisture of the hydrogel obtained in step (8) is removed, and then freeze-dried to obtain the plant tanning leather waste skin scrap based biochar aerogel adsorption material.

[0016] Further, in step (1), 200g of plant tanning leather waste skin scrap is cut into small pieces of 2-4mm, pickled with 0.5mol / L HCl solution, then stirred at room temperature at a speed of 150-200rpm for 2h, then washed with 250mL deionized water until neutral, dried in an oven at 80℃ for 12h, then put into a pulverizer for crushing, and sieved with a 60 mesh sieve for standby use

[0017] Further, in the step (2), 200 g of alfalfa is pickled with a 0.5 mol / L HCl solution, and after magnetic stirring at a speed of 150-200 rpm at room temperature for 2 h, it is washed with 250 mL of deionized water until neutral, dried in an oven at 80°C for 24 h, and then the dried alfalfa is crushed in a crusher and sieved with a 60-mesh sieve for standby use.

[0018] Further, in the step (3), the plant tannery waste skin crumb powder obtained in the step (1) and the alfalfa powder obtained in the step (2) are mixed with a 1-3 mol / L MgCl2·6H2O solution and stirred for 24 h, dried in an oven at 80°C for 24 h, and then calcined and pyrolyzed in a muffle furnace at a temperature of 500°C under oxygen-limited conditions for 2 h at a heating rate of 5°C / min to obtain a blended biochar powder.

[0019] Further, in the step (5), the biochar obtained in the step (4) is loaded into a reaction tank and placed at the plasma jet nozzle for activation, and under standard atmospheric pressure, oxygen is introduced into the dielectric barrier discharge reaction tube at a flow rate of 50-250 mL / min, and the plasma is generated by applying a voltage of 100-500 V and a current of 2-6 A, and the discharge activation is performed every 1-5 min, each activation lasts for 10-50 s, and the total activation reaction lasts for 20-60 min, and after drying, the plant tannery waste skin crumb-based biochar material is obtained.

[0020] Further, in the step (6), 1.0-3.0 g of sodium alginate is dissolved in 200 mL of deionized water, and an ultrasonic stirring alternation method is used for dispersion treatment, and after all the dispersion, the plant tannery waste skin crumb-based biochar material obtained in the step (5) is added to the sodium alginate solution for ultrasonic dispersion treatment; in the step (7), the mixed solution in the step (6) is added to a 3% calcium carbonate solution, and under the conditions of pH=6 and 60°C, an ultrasonic stirring alternation method is used, the ultrasonic is turned off after 15 min of ultrasonic, and stirring is performed for 10 min, the total ultrasonic time is 1 h, and the dispersion is uniform without clumping.

[0021] Further, in the step (8), gluconolactone is added to the biochar mixed solution obtained in the step (7) for mixing and stirring until the solution viscosity increases significantly, and it is placed for 24 h.

[0022] Further, Ca 2+ The molar ratio of the GDL is 1-2:2-1.

[0023] Further, in the step (9), the surface moisture of the hydrogel obtained in the step (8) is removed by using a vacuum freeze dryer to precool first, and then the hydrogel ball is pre-frozen in a cold trap, and then freeze-dried, and the freeze-drying time is 8-24h, so that the plant tanning leather waste skin scrap based biochar aerogel adsorption material is obtained.

[0024] Further, in the step (9), the surface moisture of the hydrogel obtained in the step (8) is removed by using a vacuum freeze dryer to precool first, and then the hydrogel ball is pre-frozen in a cold trap, and then freeze-dried, and the freeze-drying time is 8-24h, so that the plant tanning leather waste skin scrap based biochar aerogel adsorption material is obtained.

[0025] The present application introduces melamine and a nitrogen-rich plant, alfalfa, and prepares a composite biochar after metal ion impregnation modification. At high temperature, MgCl2 has strong dehydration capacity on carbohydrate polymers such as cellulose and hemicellulose, thereby changing the decomposition pathway of lignocellulosic biomass, inhibiting the formation of heavy tar, and promoting the formation of open pores in the biochar matrix. With the help of the lignin structure of alfalfa, the composite biochar prepared has a high yield and has a large specific surface area and a large number of active sites. By introducing melamine, the proportion of nitrogen-containing functional groups in the composite biochar is further increased, and the polarity and aromaticity of the composite biochar are significantly improved. The preparation of composite biochar not only helps to save resources and improve economic benefits, but also helps to reduce environmental pollution, and achieves the purpose of resource utilization of waste skin scraps.

[0026] The present application adopts dielectric barrier discharge plasma technology and vacuum freeze drying technology to prepare layered porous structure aerogel, so that it has good adsorption capacity for isoquinoline alkaloids at room temperature, and the removal rate can reach more than 93% at 25 DEG C. The present application uses waste skin scraps and alfalfa as raw materials to prepare biochar, and by introducing melamine, the proportion of oxygen and nitrogen-containing functional groups in the composite biochar is increased, and these functional groups help to improve the polarity of the material, so that it has the characteristics of adsorbing polar adsorbent isoquinoline alkaloids. The plasma technology is used to activate the adsorbent, effectively excite the groups of the material, and improve the functionality of the material. With the help of sodium alginate, Ca 2+The cross-linking between the glucarolactone and the isatin alkaloids forms a hydrogel. The material is made into an aerogel by using a vacuum freeze-drying technique, so that it is easy to recycle. The aerogel of the application has a layered porous structure, and has good adsorption effect on isatin alkaloids and strong adsorption capacity for other polar adsorbents. Through adsorption experiments, it is proved that the aerogel has strong adsorption capacity for polar adsorbents, taking isatin alkaloids berberine hydrochloride (BBH), antibiotics tetracycline (TC) and dye rhodamine B (RHB) as examples. The waste leather scraps and alfalfa are used as raw materials, and are modified and formed to have strong polarity, large specific surface area and active sites for adsorption. This is an innovative attempt to solve the problem of resource waste, which not only achieves the purpose of resource utilization of waste leather scraps, but also solves the pollution problem of isatin alkaloids. BRIEF DESCRIPTION OF DRAWINGS

[0027] The application will be described in detail below with specific examples. These examples are provided in order to more thoroughly enable one of ordinary skill in the art to understand the application and to convey the full scope of the application to the skilled person. As mentioned throughout the specification and the claims, "comprising" or "including" is an open term, which is interpreted to mean "including, but not limited to". The subsequent description is a preferred embodiment for implementing the application, and is for the purpose of the general principles of the specification, and is not intended to limit the scope of the application. The scope of protection of the application is defined by the appended claims. Unless otherwise specified, various reagents and materials used in the application can be purchased from the market.

[0028] Figure 1 The physical map of the plant tannage leather waste scrap-based biochar aerogel material of the application;

[0029] Figure 2 The SEM map of the plant tannage leather waste scrap-based biochar aerogel material of the application;

[0030] Figure 3 The EDS map of the plant tannage leather waste scrap-based biochar aerogel material of the application after adsorption;

[0031] Figure 4 The adsorption experiment map of the plant tannage leather waste scrap-based biochar aerogel material of the application;

[0032] Figure 5 The XPS N1s spectrum of the plant tannage leather waste scrap-based biochar aerogel material of the application before adsorption;

[0033] Figure 6 The XPS N1s spectrum of the plant tannage leather waste scrap-based biochar aerogel material of the application after adsorption. DETAILED DESCRIPTION Example 1

[0034] A method for preparing a plant-tanned leather waste skin scrap-based biochar aerogel adsorption material, comprising the following steps:

[0035] (1) Cut 200 g of plant-tanned leather waste skin scrap into small pieces of 2-4 mm, add 250 mL of deionized water and 5 mL of 0.5 mol / L HCl solution, and perform magnetic stirring at a speed of 150-200 rpm, then stir at room temperature for 2 h, wash with deionized water until neutral (to prevent contamination by other impurities), and place in an oven at 80°C for drying for 12 h. Then, put the dried plant-tanned leather waste skin scrap into a pulverizer for pulverization, and perform sieving treatment using a 60-mesh sieve for standby use.

[0036] (2) Add 200 g of alfalfa to 250 mL of deionized water and 5 mL of 0.5 mol / L HCl solution, and perform magnetic stirring at a speed of 150-200 rpm, then stir at room temperature for 2 h, wash with deionized water until neutral, place in an oven at 80°C for drying for 24 h, and then put the dried alfalfa into a pulverizer for pulverization, and perform sieving treatment using a 60-mesh sieve for standby use.

[0037] (3) Take 40 g of plant-tanned leather waste skin scrap powder and 40 g of alfalfa powder, mix and stir in a 1 mol / L MgCl2·6H2O solution for 4 h, and then place in an oven at 80°C for drying for 24 h. Then, under oxygen-limited conditions, pyrolyze at 500°C in a muffle furnace for 2 h to obtain blended biochar powder.

[0038] (4) Cool, grind and sieve the biochar powder prepared in step (3).

[0039] (5) Put the biochar prepared in step (4) into a reaction tank and place it at the plasma jet nozzle for activation. Collect the product and place it in a dielectric barrier discharge plasma reaction tube. Under standard atmospheric pressure, introduce oxygen into the dielectric barrier discharge reactor at a flow rate of 50 mL / min. The plasma is generated by applying a voltage of 100 V and a current of 2 A. Discharge activation is performed every 1 min, with each activation lasting 10 s. A total of 20 min of activation reaction is performed. After thorough drying, a plant-tanned leather waste skin scrap-based biochar material is obtained.

[0040] (6) Dissolve 1 g of sodium alginate in 200 mL of deionized water, and perform dispersion treatment using an ultrasonic stirring alternation method. After complete dispersion, add 20 g of plant-tanned leather waste skin scrap-based biochar powder and perform ultrasonic dispersion treatment.

[0041] (7) Add the mixed solution in step (6) to a calcium carbonate solution with a mass fraction of 3%, and perform ultrasonic stirring alternation at pH=6 and 60°C. After each 15 min of ultrasonic stirring, turn off the ultrasonic stirring and perform stirring for 10 min. The total ultrasonic stirring time is 1 h, and the dispersion is uniform without clumping.

[0042] (8) Add 1.5%, 3%, 6% of gluconolactone to the biochar mixed solution prepared in step (7) and mix and stir until the viscosity of the solution increases significantly, and then place for 12 h.

[0043] (9) Filter out the excess water of the hydrogel obtained in step (8) with filter paper, wipe off the surface water of the obtained hydrogel, pre-cool the vacuum freeze dryer, and then place the hydrogel in the cold trap for pre-freezing for 15 min after the cold trap temperature is lowered to -40℃. Then, freeze-dry under vacuum condition with a vacuum degree of 1-10 Pa, and keep the cold trap temperature at about -60℃. After drying for 8 h, the target product, a biochar aerogel adsorption material based on tannery waste leather shavings, is obtained. Example 2

[0044] The method for preparing the biochar aerogel adsorption material based on tannery waste leather shavings comprises the following steps:

[0045] (1) Cut 200 g of tannery waste leather shavings into small pieces of 2-4 mm, add 250 mL of deionized water and 5 mL of 0.5 mol / L HCl solution, and then magnetically stir at a speed of 150-200 rpm. After stirring at room temperature for 2 h, wash with deionized water until neutral (to prevent contamination by other impurities), and then dry in an oven at 80℃ for 12 h. Then, grind the dried tannery waste leather shavings in a grinder, and sieve with a 60-mesh sieve for standby use.

[0046] (2) Add 200 g of alfalfa to 250 mL of deionized water and 5 mL of 0.5 mol / L HCl solution, and then magnetically stir at a speed of 150-200 rpm. After stirring at room temperature for 2 h, wash with deionized water until neutral, and then dry in an oven at 80℃ for 24 h. Then, grind the dried alfalfa in a grinder, and sieve with a 60-mesh sieve for standby use.

[0047] (3) Take 40 g of tannery waste leather shavings powder, 30 g of alfalfa powder, and 3 g of melamine powder, mix and stir in a 1.5 mol / L MgCl2·6H2O solution for 24 h, and then dry in an oven at 80℃ for 24 h. Then, pyrolyze under oxygen-limited conditions at 500℃ in a muffle furnace for 2 h to obtain blended biochar powder.

[0048] (4) Cool, grind, and sieve the biochar powder prepared in step (3).

[0049] (5) The biochar prepared in step (4) is loaded into a reaction tank and placed at the plasma jet nozzle for activation. The collected product is placed in a dielectric barrier discharge plasma reaction tube. Oxygen is introduced into the dielectric barrier discharge reactor at a flow rate of 100 mL / min under standard atmospheric pressure. The plasma is generated by applying a voltage of 200 V and a current of 3 A. Discharge activation is performed every 2 min, with each activation lasting 20 s. The activation reaction is performed for a total of 30 min. After thorough drying, the plant tannery waste skin crumb-based biochar material is obtained.

[0050] (6) 1.5 g of sodium alginate is dissolved in 200 ml of deionized water, and dispersed by an ultrasonic stirring alternation method. After complete dispersion, 20 g of plant tannery waste skin crumb-based biochar powder is added and ultrasonically dispersed.

[0051] (7) The mixed solution in step (6) is added to a 3% calcium carbonate solution. Ultrasonic stirring is performed at a pH of 6 and a temperature of 60°C. After 15 min of ultrasonic stirring, the ultrasonic stirring is turned off, and stirring is performed for 10 min. The total ultrasonic stirring time is 1 h. The dispersion is uniform and free of lumps.

[0052] (8) Gluconolactone with a mass fraction of 1.5%, 3%, and 6% is added to the biochar mixed solution prepared in step (7) and stirred until the solution viscosity increases significantly. The solution is left to stand for 16 h.

[0053] (9) The excess water in the hydrogel obtained in step (8) is filtered out using filter paper. The surface water of the obtained hydrogel is wiped off. The vacuum freeze-drying machine is pre-cooled. The cold trap temperature is lowered to -40°C. The hydrogel is placed in the cold trap for pre-freezing for 15 min. The vacuum degree is 1-10 Pa. The cold trap temperature is maintained at about -60°C. The drying is performed for 12 h. The target product, a plant tannery waste skin crumb-based biochar aerogel adsorption material for deep treatment of isoquinoline alkaloid wastewater, is obtained. Example 3

[0054] The plant tannery waste skin crumb-based biochar aerogel adsorption material is prepared by the following steps:

[0055] (1) 200 g of plant tannery waste skin crumb is cut into small pieces of 2-4 mm. 250 mL of deionized water and 5 mL of 0.5 mol / L HCl solution are added. Magnetic stirring is performed at a speed of 150-200 rpm. After stirring at room temperature for 2 h, the solution is washed with deionized water until it is neutral (to prevent contamination by other impurities). The solution is dried in an oven at 80°C for 12 h. The dried plant tannery waste skin crumb is then ground in a grinder and sieved using a 60-mesh sieve for use.

[0056] (2) 200 g of alfalfa was added to 250 mL of deionized water, 5 mL of 0.5 mol / L HCl solution, and stirred at a speed of 150-200 rpm, then stirred at room temperature for 2 h, washed with deionized water until neutral, dried in an oven at 80°C for 24 h, then the dried alfalfa was put into a pulverizer and crushed, and sieved with a 60 mesh sieve for standby.

[0057] (3) 40 g of tannery waste skin powder, 20 g of alfalfa powder and 3 g of melamine powder were mixed in a 2 mol / L MgCl2·6H2O solution and stirred for 24 h, then dried in an oven at 80°C for 24 h. Then under oxygen-limited conditions, pyrolysis was carried out at 500°C in a muffle furnace for 2 h to obtain blended biochar powder.

[0058] (4) The biochar powder prepared in step (3) was cooled, ground and sieved.

[0059] (5) The biochar prepared in step (4) was loaded into a reaction tank and placed at the plasma jet nozzle for activation. The collected product was placed in a dielectric barrier discharge plasma reaction tube, and oxygen was introduced into the dielectric barrier discharge reactor at a flow rate of 150 mL / min under standard atmospheric pressure. Plasma was generated by applying a voltage of 300 V and a current of 4 A. Discharge activation was carried out every 3 min, each activation lasted for 30 s, and a total of 40 min of activation reaction was carried out. After thorough drying, a tannery waste skin-based biochar material was obtained.

[0060] (6) 2 g of sodium alginate was dissolved in 200 ml of deionized water, and dispersed by ultrasonic stirring alternately. After complete dispersion, 20 g of tannery waste skin-based biochar powder was added and ultrasonically dispersed.

[0061] (7) The mixed solution in step (6) was added to a 3% calcium carbonate solution, and ultrasonic stirring was carried out at pH=6 and 60°C. After ultrasonic stirring for 15 min, the ultrasonic was turned off and stirring was carried out for 10 min. The total ultrasonic time was 1 h, and the dispersion was uniform without clumping.

[0062] (8) Gluconolactone with mass fractions of 1.5%, 3% and 6% was added to the biochar mixed solution prepared in step (7) and stirred until the solution viscosity increased significantly. It was placed for 20 h.

[0063] (9) Filter out excess water from the hydrogel obtained in step (8) with filter paper, wipe off the surface water of the hydrogel, pre-cool it in a vacuum freeze dryer, and after the cold trap temperature drops to -40 ℃, put the hydrogel into the cold trap for pre-freezing for 15 min, and then freeze-dry it under vacuum conditions of 1 to 10 Pa. Keep the cold trap temperature at around -60 ℃ and dry for 16 h to obtain the target product, a vegetable tanning leather waste skin-based biochar aerogel adsorbent material for deep treatment of isoquinoline alkaloid wastewater. Example 4

[0064] A method for preparing a biochar aerogel adsorbent material based on vegetable tanned leather waste shavings includes the following steps:

[0065] (1) Cut 200g of vegetable-tanned leather waste shavings into small pieces of 2-4mm, add 250mL of deionized water and 5ml of 0.5mol / L HCl solution, stir magnetically at 150-200rpm for 2h at room temperature, wash with deionized water until neutral (to prevent contamination by other impurities), and dry in an oven at 80℃ for 12h. Then, put the dried vegetable-tanned leather waste shavings into a pulverizer and pulverize them, and sieve them through a 60-mesh sieve for later use.

[0066] (2) Add 200g of alfalfa to 250mL of deionized water and 5mL of 0.5mol / L HCl solution. Stir magnetically at 150-200rpm for 2 hours at room temperature. Wash with deionized water until neutral. Place in an oven and dry at 80℃ for 24 hours. Then, put the dried alfalfa into a grinder and grind it. Use a 60-mesh sieve for sieving.

[0067] (3) Take 40g of vegetable tanned leather waste powder, 10g of alfalfa powder and 3g of melamine powder, mix them in 2.5mol / L MgCl2·6H2O solution and stir for 24h. Then place them in an oven and dry at 80℃ for 24h. Then, under limited oxygen conditions, pyrolyze them in a muffle furnace at 500℃ for 2h to obtain blended biochar powder.

[0068] (4) Cool, grind and sieve the biochar powder prepared in step (3).

[0069] (5) The biochar prepared in step (4) is placed in a reaction tank and activated at a plasma jet nozzle. The collected product is placed in a dielectric barrier discharge plasma reaction tube. Under standard atmospheric pressure, oxygen is introduced into the dielectric barrier discharge reactor at a flow rate of 200 mL / min. The plasma is generated by applying a voltage of 400 V and a current of 5 A. Discharge activation is performed every 4 min, each activation lasts for 40 s, for a total activation reaction of 50 min. After thorough drying, vegetable tanned leather waste skin-based biochar material is obtained.

[0070] (6) 2.5 g of sodium alginate was dissolved in 200 ml of deionized water, and dispersed by ultrasonic stirring alternately. After complete dispersion, 20 g of plant tanning leather scrap-based biochar powder was added and dispersed by ultrasonic stirring.

[0071] (7) The mixed solution in step (6) was added to a 3% calcium carbonate solution by mass fraction, and dispersed by ultrasonic stirring alternately at pH = 6 and 60°C. After 15 min of ultrasonic stirring, the ultrasonic was turned off, and stirring was performed for 10 min. The total ultrasonic time was 1 h, and the dispersion was uniform without clumping.

[0072] (8) 1.5%, 3%, and 6% of gluconolactone by mass fraction were added to the biochar mixed solution prepared in step (7) and stirred until the solution viscosity increased significantly. The solution was left to stand for 24 h.

[0073] (9) The excess water in the hydrogel obtained in step (8) was filtered out using filter paper, and the surface water of the obtained hydrogel was wiped off. The hydrogel was pre-frozen in a cold trap at a temperature of -40°C for 15 min in a vacuum freeze-drying machine pre-cooled. The vacuum degree was 1-10 Pa, and the cold trap temperature was maintained at about -60°C. After drying for 20 h, a plant tanning leather scrap-based biochar aerogel adsorption material for deep treatment of isoquinoline alkaloid wastewater was obtained. Example 5

[0074] The plant tanning leather scrap-based biochar aerogel adsorption material preparation method comprises the following steps:

[0075] (1) 200 g of plant tanning leather scrap was cut into small pieces of 2-4 mm, added to 250 mL of deionized water, and 5 mL of 0.5 mol / L HCl solution was added. The mixture was stirred at a speed of 150-200 rpm, and then stirred at room temperature for 2 h. The mixture was washed with deionized water until it was neutral (to prevent contamination by other impurities), and then dried in an oven at 80°C for 12 h. The dried plant tanning leather scrap was then ground in a grinder and sieved using a 60-mesh sieve for use.

[0076] (2) 200 g of alfalfa was added to 250 mL of deionized water, and 5 mL of 0.5 mol / L HCl solution was added. The mixture was stirred at a speed of 150-200 rpm, and then stirred at room temperature for 2 h. The mixture was washed with deionized water until it was neutral, and then dried in an oven at 80°C for 24 h. The dried alfalfa was then ground in a grinder and sieved using a 60-mesh sieve for use.

[0077] (3) Take 40 g of tannery waste skin powder and 3 g of melamine powder in 3 mol / L MgCl2·6H2O solution, mix and stir for 24 h, and then dry in an oven at 80°C for 24 h. Then, under oxygen-limited conditions, pyrolyze at 500°C in a muffle furnace for 2 h to obtain blended biochar powder.

[0078] (4) Cool, grind, and sieve the biochar powder prepared in step (3).

[0079] (5) Load the biochar prepared in step (4) into a reaction tank and place it at the plasma jet nozzle for activation. Collect the product and place it in a dielectric barrier discharge plasma reaction tube. Introduce oxygen into the dielectric barrier discharge reactor at a flow rate of 250 mL / min under standard atmospheric pressure. Generate plasma by applying a voltage of 500 V and a current of 6 A. Perform discharge activation every 5 min, with each activation lasting 50 s. Perform the activation reaction for a total of 60 min. After thorough drying, obtain the tannery waste skin powder-based biochar material.

[0080] (6) Dissolve 3 g of sodium alginate in 200 ml of deionized water and disperse by alternating ultrasonic stirring. After complete dispersion, add 20 g of tannery waste skin powder-based biochar powder and disperse by ultrasonic stirring.

[0081] (7) Add the mixed solution from step (6) to a 3% calcium carbonate solution. Under the conditions of pH = 6 and 60°C, use the alternating ultrasonic stirring method. Turn off the ultrasonic after 15 min of ultrasonic stirring, and stir for 10 min. The total ultrasonic time is 1 h. Disperse until uniform and free of lumps.

[0082] (8) Add 1.5%, 3%, and 6% of gluconolactone to the biochar mixed solution prepared in step (7). Stir until the solution viscosity increases significantly, and let stand for 28 h.

[0083] (9) Filter out the excess water from the hydrogel obtained in step (8) using filter paper. Wipe off the surface moisture of the obtained hydrogel. Pre-cool the vacuum freeze-drying machine. Reduce the cold trap temperature to -40°C. Place the hydrogel in the cold trap and pre-freeze for 15 min. Perform freeze-drying under vacuum conditions with a vacuum degree of 1-10 Pa. Maintain the cold trap temperature at around -60°C. Dry for 24 h to obtain the target product, a tannery waste skin powder-based biochar aerogel adsorption material for deep treatment of isoquinoline alkaloid wastewater.

[0084] Experimental results

[0085] After comparing the adsorption performance of the aerogel materials prepared in Examples 1-5, it was found that the aerogel prepared in Example 3 (physical picture as shown in Figure 1 ) had the best adsorption effect. The SEM image is as follows:Figure 2 As shown in the figure, it can be clearly seen that the aerogel material contains a layered porous structure, which creates good conditions for the adsorption of isoquinoline alkaloids. The removal rate of isoquinoline alkaloids prepared in Example 3 is more than 93%, and the EDS map after adsorption is shown in Figure 3 As shown in the figure, it can be clearly seen that the aerogel material contains a layered porous structure, which creates good conditions for the adsorption of isoquinoline alkaloids. The removal rate of isoquinoline alkaloids prepared in Example 3 is more than 93%, and the EDS map after adsorption is shown in Figure 4 As shown in the figure, it can be clearly seen that the aerogel material contains a layered porous structure, which creates good conditions for the adsorption of isoquinoline alkaloids. The removal rate of isoquinoline alkaloids prepared in Example 3 is more than 93%, and the EDS map after adsorption is shown in

[0086] It can be understood that the above specific description of the present application is only for illustrating the present application and is not limited to the technical solutions described in the embodiments of the present application. Those skilled in the art should understand that the present application can still be modified or replaced equivalently to achieve the same technical effect. As long as it meets the use needs, it is within the protection scope of the present application.

Claims

1. A method for preparing a biochar aerogel adsorbent material based on tannery waste shavings, characterized by, The specific implementation steps are as follows: (1) The vegetable tanning leather waste skin scraps are cut into small pieces, acid washed, stirred at room temperature, washed to neutral, and dried; then the dried vegetable tanning leather waste skin scraps are put into a pulverizer for pulverization, screened, and prepared for use; (2) The alfalfa is acid washed, stirred at room temperature, washed to neutral, dried, then put into a pulverizer for pulverization, screened, and prepared for use; (3) The vegetable tanning leather waste skin scrap powder obtained in step (1), the alfalfa powder obtained in step (2), and the melamine powder are mixed and stirred in a MgCl2·6H2O solution, dried, and then calcined and pyrolyzed under limited oxygen conditions to obtain a blended biochar powder; (4) The blended biochar powder obtained in step (3) is cooled, ground, and screened; (5) The biochar obtained in step (4) is loaded into a reaction tank and placed at the plasma jet nozzle for activation, and after drying, a vegetable tanning leather waste skin scrap-based biochar material is obtained; (6) Sodium alginate is dissolved in deionized water, and an ultrasonic stirring alternation method is used for dispersion treatment, and then the vegetable tanning leather waste skin scrap-based biochar material obtained in step (5) is added to the sodium alginate solution for dispersion treatment; (7) The solution obtained in step (6) is mixed with a calcium carbonate solution and subjected to dispersion treatment; (8) Gluconolactone is added to the biochar mixed solution obtained in step (7) for mixing and stirring; (9) The surface moisture of the hydrogel obtained in step (8) is removed, and after freeze-drying, the target product, a vegetable tanning leather waste skin scrap-based biochar aerogel adsorption material, is obtained.

2. A method of preparing a biochar aerogel adsorbent material based on tannery waste shavings according to claim 1, characterized in that: In step (1), 200g of vegetable tanning leather waste skin scraps are cut into small pieces of 2-4mm, acid washed with a 0.5mol / L HCl solution, then magnetically stirred at a speed of 150-200rpm for 2h at room temperature, washed with 250mL of deionized water until neutral, dried in an oven at 80℃ for 12h, then put into a pulverizer for pulverization, and screened with a 60 mesh sieve for preparation.

3. The method of claim 2, wherein the method further comprises: In step (2), 200g of alfalfa is acid washed with a 0.5mol / L HCl solution, magnetically stirred at a speed of 150-200rpm for 2h at room temperature, then washed with 250mL of deionized water until neutral, dried in an oven at 80℃ for 24h, then put into a pulverizer for pulverization, and screened with a 60 mesh sieve for preparation.

4. The method of claim 3, wherein the method further comprises: In step (3), the vegetable tanning leather waste skin scrap powder obtained in step (1), the alfalfa powder obtained in step (2), and the melamine powder are mixed and stirred in a 1-3mol / L MgCl2·6H2O solution for 24h, dried in an oven at 80℃ for 24h, then calcined and pyrolyzed in a muffle furnace under limited oxygen conditions at a temperature of 500℃ for 2h, with a heating rate of 5℃ / min, to obtain a blended biochar powder.

5. A method of preparing a tannery waste shavings based biochar aerogel adsorbent material according to claim 4, characterized in that: In step (5), the biochar obtained in step (4) is loaded into a reaction tank and placed at the plasma jet nozzle for activation. Oxygen is introduced into the dielectric barrier discharge reaction tube at a flow rate of 50-250 mL / min under standard atmospheric pressure. The plasma is generated by applying a voltage of 100-500 V and a current of 2-6 A. Discharge activation is performed every 1-5 min, with each activation lasting 10-50 s. The activation reaction is performed for a total of 20-60 min. After drying, the plant tannery waste skin crumb-based biochar material is obtained.

6. A method of preparing a tannery waste shavings based biochar aerogel adsorbent material according to claim 5, characterized in that: In step (6), 1.0-3.0 g of sodium alginate is dissolved in 200 mL of deionized water, and the dispersion is treated using an ultrasonic stirring alternation method. After complete dispersion, the plant tannery waste skin crumb-based biochar material obtained in step (5) is added to the sodium alginate solution and subjected to ultrasonic dispersion treatment. In step (7), the mixed solution from step (6) is added to a 3% calcium carbonate solution. Under the conditions of pH=6 and 60°C, ultrasonic stirring is used alternately. After 15 min of ultrasonic treatment, the ultrasonic is turned off, and stirring is performed for 10 min. The total ultrasonic time is 1 h, and the dispersion is uniform without clumping.

7. A method of preparing a tannery waste shavings based biochar aerogel adsorbent material according to claim 6, characterized by: In step (8), gluconolactone is added to the biochar mixed solution obtained in step (7) and mixed and stirred until the solution viscosity increases significantly. The solution is left to stand for 24 h.

8. A method of preparing a tannery waste shavings based biochar aerogel adsorbent material according to claim 7, characterized by: Ca 2+ The molar ratio to the GDL was 1-2:2-1.

9. A method of preparing a tannery waste shavings based biochar aerogel adsorbent material according to claim 8, characterized in that: In step (9), the surface moisture of the hydrogel obtained in step (8) is removed. A vacuum freeze-drying machine is used for pre-cooling. The hydrogel balls are placed in a cold trap for pre-freezing. After freeze-drying, the freeze-drying time is 8-24 h. The plant tannery waste skin crumb-based biochar aerogel adsorption material is obtained.

10. The method of claim 9, wherein the method further comprises: In step (9), the surface moisture of the hydrogel obtained in step (8) is removed. A vacuum freeze-drying machine is used for pre-cooling. The hydrogel balls are placed in a cold trap for pre-freezing. After freeze-drying, the freeze-drying time is 8-24 h. The plant tannery waste skin crumb-based biochar aerogel adsorption material is obtained.

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