Preparation method of zanthoxylum bungeanum waste biochar and application of zanthoxylum bungeanum waste biochar in environmental restoration

Abstract

The invention discloses a preparation method of zanthoxylum bungeanum maxim waste biochar and application of the zanthoxylum bungeanum maxim waste biochar in environmental remediation, and relates to the technical field of antibiotic pollution, the preparation method of the zanthoxylum bungeanum maxim waste biochar comprises the following steps: taking zanthoxylum bungeanum maxim waste as a raw material, drying, crushing and sieving the zanthoxylum bungeanum maxim waste to obtain a powdery material, and performing KOH activation treatment on the zanthoxylum bungeanum maxim waste then, the powder is placed in a tubular furnace and subjected to high-temperature pyrolysis in an inert atmosphere, and the modified zanthoxylum charcoal is obtained. The prepared Chinese prickly ash biochar has high specific surface area and pore volume, has a remarkable adsorption effect on tetracycline in a water body, and is stable in performance. Meanwhile, the preparation method is simple, large-scale popularization and application are easy, recycling of waste resources is achieved, and the environment-friendly biochar material with excellent adsorption performance is provided for adsorption and purification of antibiotic wastewater.

Description

Technical Field

[0001] The invention relates to the technical field of antibiotic pollution, and specifically to a method for preparing biochar from waste Zanthoxylum bungeanum and application thereof in environmental remediation. Background Art

[0002] With the growing concerns over water pollution, the presence of tetracyclines in aquatic environments has attracted great attention due to their potential ecological and health risks. Tetracyclines are a class of broad-spectrum antibiotics notorious for their high solubility and resistance to natural degradation processes, leading to their widespread discovery in surface and groundwater sources. The widespread use of these antibiotics in healthcare and veterinary medicine promotes their persistence in the environment, posing considerable challenges to water treatment technologies, and therefore, the removal of tetracyclines from aquatic environments is of great importance.

[0003] There are many traditional procedures such as distillation, reverse osmosis, sedimentation and lime softening, which are used at different stages of wastewater treatment; however, although these technologies are low-cost and harmless, they cannot completely eliminate them from wastewater. Batch processes and continuous processes are the main adsorption processes for removing antibiotics from wastewater, and both can be used with a variety of adsorbents such as ultrafiltration, microfiltration, nanofiltration, membrane bioreactor treatment, advanced oxidation processes, reverse osmosis and nanoadsorbents. Conventional wastewater treatment plants cannot effectively eliminate antibiotics / resistance genes. Because they are present in stagnant wastewater ponds, municipal sewage, hospital sewage, surface water and groundwater. The differences in each treatment process, biological and chemical oxygen demand, as well as water quality conditions and environmental factors, can affect the removal efficiency of antibiotics. At present, adsorption has various advantages compared to other remediation methods, including simplicity, reliability, minimal energy usage and rapid adsorbent recovery.

[0004] Among these adsorbents, biochar has been widely studied in the remediation of water bodies contaminated by heavy metals or organic compounds. Biochar has the characteristics of wide raw material sources, large specific surface area, and well-developed pore structure, and the functional groups and minerals in biochar play an important role in the removal of pollutants from wastewater or soil. Biochar, a carbon-rich product from the pyrolysis of biomass under oxygen-limited conditions, has become a promising adsorbent for the removal of various environmental pollutants, including tetracycline. Its unique properties, such as high surface area, porosity, and functional groups, endow biochar with exceptional adsorption capacity. In addition, modification of biochar by alkaline treatment has been shown to improve its adsorption efficiency, which may be due to the increased surface area and the introduction of new functional groups that promote interaction with pollutants.

[0005] In the context of agricultural waste utilization and environmental remediation, the stabilization of waste plant materials, such as Zanthoxylum bungeanum, represents an innovative approach for sustainable waste management and pollution control. The development of biochar from these waste materials followed by alkaline modification could provide a cost-effective and environmentally friendly solution for the elimination of tetracyclines from water bodies. Summary of the invention

[0006] In view of the deficiencies in the prior art, the present invention provides a method for preparing biochar from Zanthoxylum bungeanum waste and its application in environmental remediation, which solves the problems raised in the above-mentioned background technology.

[0007] To achieve the above objectives, the present invention is implemented through the following technical solutions: a method for preparing biochar from waste Zanthoxylum bungeanum and its application in environmental remediation,

[0008] The following steps are involved:

[0009] (1) The waste Zanthoxylum bungeanum is processed by drying, crushing and sieving to obtain a powdery material.

[0010] (2) Weigh the raw material powder obtained in step (1) and disperse it in KOH, add distilled water, stir it continuously, and dry it in an oven to remove moisture.

[0011] (3) Weigh the processed pepper seed powder in step (2) in a mortar, grind it through a sieve, weigh an appropriate amount of pepper powder in a tubular furnace, shake it to make it uniform, set the heating rate and heating temperature, keep it warm for a period of time, and fully pyrolyze it.

[0012] (4) After the temperature of the Zanthoxylum bungeanum biochar prepared in step (3) drops to room temperature, the biochar prepared in the tubular furnace is taken out and washed with hydrochloric acid, then rinsed with distilled water for multiple times, and placed in an oven for drying.

[0013] (5) The biochar dried in step (4) is taken out, ground with a mortar and sieved, and then placed in a sealed bag for later use, thereby preparing Zanthoxylum bungeanum biochar.

[0014] According to a further technical solution, in step (1), the drying temperature of the waste Zanthoxylum bungeanum is set to 80° C., and the waste Zanthoxylum bungeanum is sieved through a 100-mesh sieve after being crushed.

[0015] A further technical solution is that in step (2), the raw material powder is 20 g, the mass of KOH is 20 g, 50 ml of distilled water is added, the continuous stirring time is 12 hours, the stirring temperature is 25°C, and the oven drying temperature is 80°C.

[0016] In a further technical solution, in step (3), the grinding screen is 100 mesh, and the heating rate is set to 10°C·min -1First, N2 is introduced to remove oxygen. The pyrolysis temperature is 400-800℃. After the temperature is raised to the set temperature, the temperature is kept constant for 2 hours to allow the material to be fully pyrolyzed.

[0017] According to a further technical solution, in step (4), the hydrochloric acid concentration is 0.1 M, the pickling time is 12 hours, the surface is rinsed until the pH is neutral, and the oven drying temperature is 80°C.

[0018] According to a further technical solution, in step (5), the sieve is 100 mesh.

[0019] The present invention also protects a kind of Zanthoxylum bungeanum biochar and the application of the Zanthoxylum bungeanum biochar as a tetracycline removal adsorbent in environmental remediation of tetracycline-containing wastewater.

[0020] Furthermore, the specific adsorption process is: adding pepper biochar to wastewater containing different tetracycline concentrations, adjusting the solution pH, and oscillating in a constant temperature oscillator. The addition amount of pepper biochar is 0.25-4g / L, the reaction temperature is 15°C, 25°C, and 35°C, the initial concentration of the antibiotic solution is 20-100mg / L, the solution pH is adjusted to 2-12, and the oscillation rate is 180r / min to study the effects of different conditions on adsorption performance. The present invention provides a method for preparing pepper waste biochar and its application in environmental remediation, which has the following beneficial effects:

[0021] 1. The preparation method of the biochar from waste Zanthoxylum bungeanum and its application in environmental remediation, using KOH solution to immerse and modify the waste Zanthoxylum bungeanum can change the structure of the waste Zanthoxylum bungeanum. Within a certain range, the increase of the KBC preparation temperature can increase its crushing degree, increase the specific surface area of ​​the biochar, reduce the pore size, and increase the number of its micropores, which is beneficial to increase its total specific surface area and the number of adsorption sites, thereby enhancing the pore filling effect of the biochar and having stronger adsorption performance. Moreover, the activation treatment can change the elemental composition of the biochar of Sichuan pepper. When treating sewage containing tetracycline, the functional groups on the biochar of Sichuan pepper can generate electrostatic attraction and react with tetracycline, and the developed graphite structure in the biochar can combine with tetracycline through π-π interaction. During the activation process, KOH can react not only with carbon, but also with oxygen and hydrogen in the biochar, thereby reducing the intensity of the characteristic peak. This is due to the removal of the carbonyl functional group at high temperature, which may contribute to the formation of hydrogen bonds between nitrogen-containing and oxygen-containing groups on the pollutants. Compared with the prior art, the present invention has the following beneficial effects: the biochar of Sichuan pepper prepared by the present invention uses discarded Sichuan pepper biomass, which has abundant raw material sources, low prices and low preparation costs; the present invention uses KOH activation to modify the biochar, and increases the specific surface area and pore volume through activation. The specific surface area of ​​the biochar of Sichuan pepper reaches 983.754m 2 g -1, thereby enhancing the reaction rate and adsorption capacity; the preparation method of the present invention is simple, easy to promote and apply on a large scale, and enriches the resource recycling methods of Zanthoxylum bungeanum waste. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 (a), (c), and (e) are scanning electron microscope images of KBC400, KBC600, and KBC800 at 700 times magnification, respectively; (b), (d), and (f) are scanning electron microscope images of KBC400, KBC600, and KBC800 at 15,000 times magnification, respectively.

[0023] Figure 2 (a): XRD diffraction patterns of KBC400, KBC600 and KBC800; (b): FT-IR spectra of KBC400, KBC600 and KBC800.

[0024] Figure 3 N2 adsorption-desorption isotherms of KBC (inset: pore size distribution diagram); (a): KBC400; (b): KBC600; (c): KBC800.

[0025] Figure 4 Effect of different KBC dosages on tetracycline adsorption; (ac): Changes in removal rate over time; (df): Effect of KBC dosage on adsorption capacity.

[0026] Figure 5 Effect of different temperatures on the adsorption of tetracycline by KBC.

[0027] Figure 6 Effect of different pH on the adsorption of tetracycline by KBC.

[0028] Figure 7 Effect of different initial tetracycline concentrations on KBC adsorption. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0030] See also Figures 1 to 7 The present invention provides a technical solution: Various exemplary embodiments of the present invention are now described in detail. The detailed description should not be considered as a limitation of the present invention, but should be understood as a more detailed description of certain aspects, characteristics and implementation schemes of the present invention.

[0031] It should be understood that the terms described in the present invention are only for describing special embodiments and are not intended to limit the present invention. In addition, for the numerical range in the present invention, it should be understood that each intermediate value between the upper and lower limits of the scope is also specifically disclosed. Each smaller range between the intermediate value in any stated value or stated range and any other stated value or intermediate value in the described range is also included in the present invention. The upper and lower limits of these smaller ranges can be independently included or excluded in the scope.

[0032] Unless otherwise indicated, all technical and scientific terms used herein have the same meanings as those generally understood by those skilled in the art. Although the present invention describes only preferred methods and materials, any methods and materials similar or equivalent to those described herein may also be used in the implementation or testing of the present invention. All documents mentioned in this specification are incorporated by reference to disclose and describe the methods and / or materials associated with the documents. In the event of a conflict with any incorporated document, the content of this specification shall prevail.

[0033] It will be apparent to those skilled in the art that various modifications and variations may be made to the specific embodiments of the present invention description without departing from the scope or spirit of the present invention. Other embodiments derived from the present invention description will be apparent to the skilled artisan. The present invention description and examples are exemplary only.

[0034] The words “include,” “including,” “have,” “contain,” etc. used in this document are open-ended terms, meaning including but not limited to.

[0035] The technical solution of the present invention is as follows: A method for preparing biochar from waste Zanthoxylum bungeanum, comprising the following steps;

[0036] Accurately weigh a certain mass of Zanthoxylum bungeanum waste raw material, and dry it in an oven at 80°C for later use;

[0037] Weigh 20g of ground pepper seed powder and pepper cake and disperse them in 20g of KOH (mass ratio 1:1), add 50ml of distilled water, stir continuously for 12 hours and dry in an oven at 80℃ to remove moisture.

[0038] Weigh the treated Zanthoxylum bungeanum seed powder in a mortar and grind it to pass through a 100-mesh sieve. Weigh an appropriate amount of Zanthoxylum bungeanum powder in a tubular furnace and shake it to make it uniform. Set the heating rate to 10°C·min-1. First, introduce N2 to remove oxygen. After the temperature reaches the set temperature, keep the temperature constant for 2 hours to allow the material to be fully pyrolyzed. After the temperature drops to room temperature, take out the biochar prepared in the tubular furnace and pickle it with 0.1M hydrochloric acid for 12 hours. Then rinse it with distilled water several times until the pH is neutral, place it in an oven, and dry it in an oven at 80°C. Take out the dried biochar, grind it with a mortar to pass through a 100-mesh sieve, and put it in a sealed bag for later use to prepare Zanthoxylum bungeanum biochar.

[0039] The following is a specific description in conjunction with the embodiments:

[0040] Example 1

[0041] Accurately weigh a certain mass of Zanthoxylum bungeanum waste raw material, and dry it in an oven at 80°C for later use;

[0042] Weigh 20g of ground pepper seed powder and pepper cake and disperse them in 20g of KOH (mass ratio 1:1), add 50ml of distilled water, stir continuously for 12 hours and dry in an oven at 80℃ to remove moisture.

[0043] Weigh the treated pepper seed powder in a mortar and grind it to pass through a 100-mesh sieve. Weigh an appropriate amount of pepper powder in a tubular furnace and shake it to make it uniform. The pyrolysis temperature is set to 400°C, and the heating rate is set to 10°C·min-1. N2 is first introduced to remove oxygen. After the temperature is raised to the set temperature, the temperature is kept constant for 2 hours to allow the material to be fully pyrolyzed. After the temperature drops to room temperature, the biochar prepared in the tubular furnace is taken out and pickled with 0.1M hydrochloric acid for 12 hours, and then rinsed with distilled water several times until the pH is neutral, placed in an oven, and dried in an oven at 80°C. The dried biochar is taken out, ground with a mortar to pass through a 100-mesh sieve, and then put into a sealed bag for later use to prepare pepper biochar, recorded as KBC400.

[0044] Weigh a certain amount of KBC400, add the required concentration of tetracycline to a 100mL conical flask, oscillate at the required temperature in a constant temperature shaking incubator (180r / min), take the supernatant according to the specific adsorption time, filter through a 0.22um filter membrane, and measure the absorbance at 350nm using a UV-visible spectrophotometer. And by changing the amount of biochar added 0.25-4g / L, the reaction temperature of 15℃, 25℃, 35℃, the initial concentration of the antibiotic solution 20-100mg / L, pH 2-12 to study the effect of different conditions on the adsorption performance.

[0045] Example 2

[0046] Accurately weigh a certain mass of Zanthoxylum bungeanum waste raw material, and dry it in an oven at 80°C for later use;

[0047] Weigh 20g of ground pepper seed powder and pepper cake and disperse them in 20g of KOH (mass ratio 1:1), add 50ml of distilled water, stir continuously for 12 hours and dry in an oven at 80℃ to remove moisture.

[0048] Weigh the processed pepper seed powder in a mortar and grind it to pass through a 100-mesh sieve. Weigh an appropriate amount of pepper powder in a tube furnace and shake it to make it uniform. Set the pyrolysis temperature to 600 °C and the heating rate to 10 °C min. -1 First, N2 is introduced to remove oxygen. After the temperature is raised to the set temperature, the temperature is kept constant for 2 hours to allow the material to be fully pyrolyzed. After the temperature drops to room temperature, the biochar prepared in the tube furnace is taken out and pickled with 0.1M hydrochloric acid for 12 hours. Then, it is rinsed with distilled water several times until the pH is neutral, placed in an oven, and dried in an oven at 80°C. The dried biochar is taken out, ground with a mortar and sieved through a 100-mesh sieve, and then put into a sealed bag for later use to prepare the Zanthoxylum biochar, which is recorded as KBC600.

[0049] Weigh a certain amount of KBC600, add the required concentration of tetracycline to a 100mL conical flask, oscillate at the required temperature in a constant temperature shaking incubator (180r / min), take the supernatant according to the specific adsorption time, filter through a 0.22um filter membrane, and measure the absorbance at 350nm using a UV-visible spectrophotometer. And by changing the amount of biochar added 0.25-4g / L, the reaction temperature of 15℃, 25℃, 35℃, the initial concentration of the antibiotic solution 20-100mg / L, pH 2-12 to study the effect of different conditions on the adsorption performance.

[0050] Example 3

[0051] Accurately weigh a certain mass of Zanthoxylum bungeanum waste raw material, and dry it in an oven at 80°C for later use;

[0052] Weigh 20g of ground pepper seed powder and pepper cake and disperse them in 20g of KOH (mass ratio 1:1), add 50ml of distilled water, stir continuously for 12 hours and dry in an oven at 80℃ to remove moisture.

[0053] Weigh the processed pepper seed powder in a mortar and grind it to pass through a 100-mesh sieve. Weigh an appropriate amount of pepper powder in a tube furnace and shake it to make it uniform. Set the pyrolysis temperature to 800 °C and the heating rate to 10 °C min. -1First, N2 is introduced to remove oxygen. After the temperature is raised to the set temperature, the temperature is kept constant for 2 hours to allow the material to be fully pyrolyzed. After the temperature drops to room temperature, the biochar prepared in the tube furnace is taken out and pickled with 0.1M hydrochloric acid for 12 hours. Then, it is rinsed with distilled water several times until the pH is neutral, placed in an oven, and dried in an oven at 80°C. The dried biochar is taken out, ground with a mortar and sieved through a 100-mesh sieve, and then put into a sealed bag for later use to prepare the Zanthoxylum biochar, which is recorded as KBC800.

[0054] Weigh a certain amount of KBC800, add the required concentration of tetracycline to a 100mL conical flask, oscillate at the required temperature in a constant temperature shaking incubator (180r / min), take the supernatant according to the specific adsorption time, filter through a 0.22um filter membrane, and measure the absorbance at 350nm using a UV-visible spectrophotometer. And by changing the amount of biochar added 0.25-4g / L, the reaction temperature is 15℃, 25℃, 35℃, the initial concentration of the antibiotic solution is 20-100mg / L, and the pH is 2-12 to study the effect of different conditions on the adsorption performance.

[0055] The amount of antibiotics adsorbed by biochar q e The adsorption performance of biochar is evaluated by the size of (mg / g) and adsorption removal rate R (%). The calculation formulas are shown in (1.1) and (1.2).

[0056]

[0057] Where: C0 is the initial concentration of antibiotics (mg / L); C e is the antibiotic concentration at adsorption equilibrium (mg / L); V is the solution volume (L); M is the amount of biochar added (g).

[0058] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for preparing biochar from Zanthoxylum bungeanum waste, characterized in that: The following steps are involved: Step (1): treating the Zanthoxylum bungeanum waste by drying, crushing and sieving it to obtain a powdered material; Step (2): weigh the raw material powder obtained in step (1), disperse it in KOH, add distilled water, stir it continuously, and dry it in an oven to remove moisture; Step (3): weigh the processed pepper seed powder in step (2) in a mortar, grind through a sieve, weigh an appropriate amount of pepper powder in a tube furnace, shake it to make it uniform, set the heating rate and heating temperature, keep it warm for a period of time, and fully pyrolyze it; Step (4): after the temperature of the Zanthoxylum bungeanum biochar prepared in step (3) drops to room temperature, the biochar prepared in the tube furnace is taken out and washed with hydrochloric acid, then rinsed with distilled water for multiple times, and placed in an oven for drying; Step (5): Take out the biochar dried in step (4), grind it with a mortar and sieve it, and then put it into a sealed bag for later use, so as to prepare the Zanthoxylum bungeanum biochar.

2. The method for preparing biochar from Zanthoxylum bungeanum waste according to claim 1, characterized in that: In step (1), the drying temperature of the Zanthoxylum bungeanum waste is set to 80° C., and the Zanthoxylum bungeanum waste is sieved through a 100-mesh sieve after being crushed.

3. The method for preparing biochar from Zanthoxylum bungeanum waste according to claim 1, characterized in that: In step (2), the raw material powder is 20 g, the mass of KOH is 20 g, 50 ml of distilled water is added, the continuous stirring time is 12 hours, the stirring temperature is 25°C, and the oven drying temperature is 80°C.

4. The method for preparing biochar from Zanthoxylum bungeanum waste according to claim 1, characterized in that: In step (3), the grinding screen is 100 mesh, and the heating rate is set to 10°C min -1 First, N2 is introduced to remove oxygen. The pyrolysis temperature is 400-800℃. After the temperature is raised to the set temperature, the temperature is kept constant for 2 hours to allow the material to be fully pyrolyzed.

5. The method for preparing biochar from Zanthoxylum bungeanum waste according to claim 1, characterized in that: In step (4), the hydrochloric acid concentration is 0.1 M, the pickling time is 12 hours, the surface is rinsed until the pH is neutral, and the oven drying temperature is 80°C.

6. The method for preparing biochar from Zanthoxylum bungeanum waste according to claim 1, characterized in that: In step (5), the sieve is 100 mesh.

7. The use of a Zanthoxylum bungeanum waste biochar as described in claims 1-6 as an adsorbent for removing tetracycline in tetracycline-containing wastewater in environmental remediation, the specific adsorption process is: adding the Zanthoxylum bungeanum biochar to wastewater containing different tetracycline concentrations, adjusting the solution pH, and oscillating in a constant temperature oscillator, the addition amount of the Zanthoxylum bungeanum biochar is 0.25-4g / L, the reaction temperature is 15°C, 25°C, and 35°C, the initial concentration of the antibiotic solution is 20-100mg / L, the solution pH is adjusted to 2-12, and the oscillation rate is 180r / min, to study the influence of different conditions on the adsorption performance.

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