Preparation process of biochar adsorbent loaded with iron ions

Abstract

The invention discloses a preparation process of a biochar adsorbent loaded with iron ions, which comprises the following steps: A, washing, chopping and drying bamboos, carbonizing the bamboos, cooling to room temperature, and grinding and screening the carbonized bamboos to form carbon powder; b, soaking carbon powder in an acid solution, centrifuging to remove supernate, and drying the obtained product at 60-80 DEG C to obtain a bamboo biochar product; c, ultrapure water is added into a container, a Fe < 2 + > / Fe < 3 + > solution is weighed according to the proportion, the carbon product is added into the Fe < 2 + > / Fe < 3 + > solution and evenly stirred, a NaOH solution is slowly and dropwise added, standing is carried out, supernate is removed, centrifugation is carried out, and finally the biochar adsorbent loaded with the iron ions is obtained. According to the present invention, the porous tubular shape is formed under the microstructure, the iron ions are uniformly dispersed on the biochar surface, the specific surface area of the biochar is effectively increased, and more ion exchange sites are exposed on the surface so as to improve the adsorption effect, such that the antibiotics in the water can be rapidly and efficiently removed.

Description

Technical Field

[0001] The present invention relates to the technical field of biochar adsorbents, and in particular to a preparation process of a biochar adsorbent loaded with iron ions. Background Art

[0002] Antibiotics are a new type of pollutant that has attracted widespread attention from researchers in recent years. With the widespread use of antibiotics in various fields, such as disease prevention and control, agricultural production, animal husbandry, and aquaculture, the number of antibiotics detected in aquatic environments has increased. The presence of these pollutants in aquatic environments poses a significant threat to human health and the entire ecosystem. On the one hand, long-term consumption of water or food containing trace amounts of antibiotics can lead to the emergence of drug resistance, resulting in the emergence of antibiotic-resistant genes and resistant bacteria. On the other hand, large amounts of antibiotics used by humans and livestock eventually enter the environment, negatively impacting non-target organisms in aquatic ecosystems, including freshwater algae, microphytes, macrophytes, zooplankton, and fish.

[0003] The limited efficiency of current water treatment processes for antibiotics, coupled with the inherent difficulty of antibiotic degradation, has made them a focus of considerable research interest. Research indicates that currently widely used advanced water treatment technologies include membrane technology, advanced oxidation technology, activated carbon adsorption technology, and other modified biochar technologies. Adsorption technology, due to its low cost and ease of operation, is widely used in water treatment. Furthermore, biological activated carbon adsorption is a currently garnering significant attention as a deep treatment technology, offering advantages such as high efficiency, low pollution, and easy preparation.

[0004] However, unmodified biochar typically exhibits poor adsorption capacity and can cause pigment contamination in the treated water source. Due to its inherent soluble groups, it can increase BOD, COD, and TOC levels in the water. Furthermore, its stability and regeneration are poor. Therefore, in practical applications, biochar modification is often necessary. Summary of the Invention

[0005] In order to solve the above-mentioned deficiencies in the prior art, the present invention proposes a preparation method of calcined calcium-containing talc.

[0006] In order to solve the above technical problems, the present invention adopts the following technical solution: a preparation process of a biochar adsorbent loaded with iron ions, comprising the following steps:

[0007] A. After washing, chopping and drying the bamboo, carbonizing it, cooling it to room temperature, and then grinding and sieving the carbonized bamboo to form carbon powder;

[0008] B. Soaking the carbon powder obtained in step A in an acidic solution, washing the carbon powder with ultrapure water and centrifuging the mixture. After centrifugation, the supernatant was removed and the resulting product was dried at 60-80 degrees Celsius for 6-14 hours to obtain a bamboo biochar product.

[0009] C. Add ultrapure water to the container, weigh 3-6g FeSO4.7H2O and Fe2(SO4)3 according to the ratio, dissolve them in water, and stir to obtain Fe 2+ / Fe 3+ solution, add the bamboo biochar product obtained in step B to Fe 2+ / Fe 3+ The solution is stirred evenly. When the suspension is evenly mixed, NaOH solution is slowly added dropwise to adjust the pH value of the system to 10.5-11.5. The bamboo biochar product is then allowed to settle naturally, and the supernatant is discarded. The bamboo biochar product is washed with ultrapure water and ethanol respectively and centrifuged at least once. Finally, the obtained product is placed at 60-80 degrees Celsius and dried for 6-14 hours to obtain a biochar adsorbent loaded with iron ions.

[0010] Furthermore, in step A, the bamboo is washed and chopped, and then the chopped bamboo is placed in a drying oven and dried at 60-80 degrees Celsius for 6-14 hours to constant weight, and then placed in a resistance furnace and kept in an argon atmosphere at 300-500 degrees Celsius for 3-8 hours to carbonize it, and the temperature of the drying oven is 70 degrees Celsius, the drying time is 12 hours, the temperature in the resistance furnace is 400 degrees Celsius, and the holding time is 4 hours. In step A, a 20-mesh screen is used for screening.

[0011] Furthermore, in step B, the pickling solution is a hydrochloric acid solution, and the carbon powder obtained in step A is placed in the hydrochloric acid solution and soaked for 10-16 hours, then the carbon powder is washed with ultrapure water and centrifuged more than once, the concentration of the hydrochloric acid solution is 1 mol·L-1, and the carbon powder is soaked in the hydrochloric acid solution for 12 hours.

[0012] Furthermore, in step B, the carbon powder is washed with ultrapure water and centrifuged three times, the centrifugal speed is 4000 r·min-1, the centrifugal time is 10 min, and the drying time of the bamboo biochar product obtained by centrifugation is 12 hours, and the drying temperature is 70 degrees Celsius.

[0013] Further, in step C, ultrapure water is added to the container, and 3-6g FeSO4.7H2O and 4g-5g Fe2(SO4)3 are weighed and dissolved in 600-1000ml ultrapure water, and stirred to obtain Fe 2+ / Fe 3+ solution.

[0014] Furthermore, in step C, 5 g of FeSO4.7H2O and 4.5 g of Fe2(SO4)3 were dissolved in every 800 ml of ultrapure water, and the weight of the added bamboo biochar product was 10 g.

[0015] Furthermore, in step C, FeSO4.7H2O and Fe2(SO4)3 are dissolved in ultrapure water to obtain Fe 2+ / Fe 3+ The solution was stirred on a magnetic stirrer for 20 min. 2+ / Fe 3+ The solution was stirred for 0.5 hours.

[0016] Furthermore, in step C, the concentration of the NaOH solution is 5 mol·L-1, and the NaOH solution adjusts the pH value of the suspension system to 11.

[0017] Furthermore, in step C, the sample was washed and centrifuged three times with ultrapure water and ethanol respectively, the centrifugal speed was 4000 r·min-1, the centrifugal time was 10 min, and the drying time of the biochar adsorbent loaded with iron ions obtained after centrifugation was 12 hours, and the drying temperature was 70 degrees Celsius.

[0018] A biochar adsorbent loaded with iron ions is prepared according to the preparation process of any one of claims 1 to 9.

[0019] Compared with the prior art, the present invention has the following beneficial effects: the biochar adsorbent loaded with iron ions prepared according to the process of the present invention is porous tubular in microstructure, and the iron ions are evenly dispersed on the surface of the biochar, which effectively increases the specific surface area of ​​the biochar and exposes more ion exchange sites on the surface, thereby improving the adsorption effect, so that antibiotics in water can be removed quickly and efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The present invention will be further explained below with reference to the accompanying drawings and specific embodiments.

[0021] Figure 1 This is the SEM image of bamboo biochar adsorbent;

[0022] Figure 2 This is the SEM image of bamboo biochar loaded with iron ions;

[0023] Figure 3 These are the magnetization curves of bamboo biochar and bamboo biochar adsorbent loaded with iron ions. DETAILED DESCRIPTION

[0024] The invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0025] Reference Figures 1 to 3 A process for preparing a biochar adsorbent loaded with iron ions comprises the following steps:

[0026] A. Wash and chop bamboo, then place the chopped bamboo in a drying oven and dry it at 60-80 degrees Celsius for 6-14 hours to constant weight. Then place it in a resistance furnace and maintain it in an argon atmosphere at 300-500 degrees Celsius for 3-8 hours to carbonize it. Then cool it to room temperature, and then grind and sieve the carbonized bamboo to form carbon powder.

[0027] B. Soaking the carbon powder obtained in step A in a hydrochloric acid solution for 10-16 hours, washing the carbon powder with ultrapure water and centrifuging at least once, removing the supernatant after centrifugation, and drying the resulting product at 60-80 degrees Celsius for 6-14 hours to obtain a bamboo biochar product;

[0028] C. Add ultrapure water to the container, weigh 3-6g FeSO4.7H2O and 4g~5g Fe2(SO4)3 per 600-1000ml ultrapure water, dissolve them in it, and stir to obtain Fe 2+ / Fe 3+ solution, add the bamboo biochar product obtained in step B to Fe 2+ / Fe 3+ The solution is stirred evenly. When the suspension is evenly mixed, NaOH solution is slowly added dropwise to adjust the pH value of the system to 10.5-11.5. The bamboo biochar product is then allowed to settle naturally, and the supernatant is discarded. The bamboo biochar product is washed with ultrapure water and ethanol respectively and centrifuged at least once. Finally, the obtained product is placed at 60-80 degrees Celsius and dried for 6-14 hours to obtain a biochar adsorbent loaded with iron ions.

[0029] The iron ion-loaded biochar adsorbent prepared according to the process of the present invention has a porous tubular microstructure, and the iron ions are evenly dispersed on the surface of the biochar, which effectively increases the specific surface area of ​​the biochar and exposes more ion exchange sites on the surface, thereby improving the adsorption effect, so that antibiotics in water can be removed quickly and efficiently.

[0030] On this basis, optimization was performed. Preferably, in step A, the temperature of the drying oven was 70 degrees Celsius, the drying time was 12 hours, the temperature in the resistance furnace was 400 degrees Celsius, and the holding time was 4 hours.

[0031] Further optimization is performed, and it is preferred that in step A, a 20-mesh sieve is used for screening during the screening process.

[0032] Further optimization was performed, and it was preferred that in step B, the concentration of the hydrochloric acid solution was 1 mol·L-1, and the time for the carbon powder to be immersed in the hydrochloric acid solution was 12 hours.

[0033] Further optimization was performed. It was preferred that in step B, the carbon powder was washed with ultrapure water and centrifuged three times, the centrifugal speed was 4000 r·min-1, the centrifugal time was 10 min, and the drying time of the bamboo biochar product obtained after centrifugation was 12 hours at a drying temperature of 70 degrees Celsius.

[0034] Further optimization was performed, and it was preferred that in step C, 5 g of FeSO4.7H2O and 4.5 g of Fe2(SO4)3 were dissolved in every 800 ml of ultrapure water, and the weight of the added bamboo biochar product was 10 g.

[0035] Further optimization was performed, and it was preferred that in step C, FeSO4.7H2O and Fe2(SO4)3 were dissolved in ultrapure water to obtain Fe 2+ / Fe 3 + The solution was stirred on a magnetic stirrer for 20 min. 2 + / Fe 3+ The solution was stirred for 0.5 hours.

[0036] Further optimization is performed. In the above process, preferably in step C, the concentration of the NaOH solution is 5 mol·L-1, and the NaOH solution adjusts the pH value of the suspension system to 11.

[0037] Further optimization, in step C, the sample is washed and centrifuged three times with ultrapure water and ethanol respectively, the centrifugal speed is 4000 r·min-1, the centrifugal time is 10 min, and the drying time of the biochar adsorbent loaded with iron ions obtained after centrifugation is 12 hours, and the drying temperature is 70 degrees Celsius.

[0038] The biochar adsorbent was prepared as described above and then tested. The experiment of simulating the removal of antibiotics from wastewater by the biochar adsorbent loaded with iron ions in the laboratory was as follows (taking ciprofloxacin as an example):

[0039] Prepare simulated wastewater containing ciprofloxacin, add 50 ml of simulated wastewater and biochar adsorbent loaded with iron ions into a polypropylene test tube, then place the polypropylene test tube in a constant temperature shaker and shake it at a rate of 200 rpm for a period of time, and then test the removal rate of ciprofloxacin. Multiple measurements were performed at different temperatures, reaction times, dosages, and pH values. The results are as follows: Figures 1 to 3As shown in the figure, the removal capacity was compared with that of existing activated carbon. The results showed that the effect was far superior to that of ordinary activated carbon, especially when the initial pH value of the ciprofloxacin solution was 3, the initial concentration was 2000ug·L-1, the experimental temperature was 25℃, and the oscillator oscillation rate was 200r·min. -1 Under the conditions of 100 mg of biochar adsorbent loaded with iron ions and 3 h of adsorption time, the removal rate of ciprofloxacin by the prepared biochar adsorbent loaded with iron ions was as high as 79.1%, providing reliable theoretical and experimental data support for practical applications.

[0040] The above embodiments merely illustrate several implementations of the present invention, and while their descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the present invention. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the spirit of the present invention, all of which fall within the scope of protection of the present invention. Therefore, the patent and scope of protection of the present invention shall be subject to the appended claims.

Claims

1. A process for preparing a biochar adsorbent loaded with iron ions, characterized in that: The following steps are involved: A. After washing, chopping and drying the bamboo, carbonizing it, cooling it to room temperature, and then grinding and sieving the carbonized bamboo to form carbon powder; B. Soaking the carbon powder obtained in step A in an acidic solution, washing the carbon powder with ultrapure water and centrifuging the mixture. After centrifugation, the supernatant was removed and the resulting product was dried at 60-80 degrees Celsius for 6-14 hours to obtain a bamboo biochar product. C. Add ultrapure water to the container, weigh 3-6g FeSO4.7H2O and Fe2(SO4)3 according to the ratio, dissolve them in water, and stir to obtain Fe 2+ / Fe 3+ solution, add the bamboo biochar product obtained in step B to Fe 2+ / Fe 3+ The solution is stirred evenly. When the suspension is evenly mixed, NaOH solution is slowly added dropwise to adjust the pH value of the system to 10.5-11.

5. The bamboo biochar product is then allowed to settle naturally, and the supernatant is discarded. The bamboo biochar product is washed with ultrapure water and ethanol respectively and centrifuged at least once. Finally, the obtained product is placed at 60-80 degrees Celsius and dried for 6-14 hours to obtain a biochar adsorbent loaded with iron ions.

2. The process for preparing a biochar adsorbent loaded with iron ions according to claim 1, wherein: In step A, the bamboo is washed and chopped, and then the chopped bamboo is placed in a drying oven and dried at 60-80 degrees Celsius for 6-14 hours to constant weight, and then placed in a resistance furnace and kept in an argon atmosphere at 300-500 degrees Celsius for 3-8 hours to carbonize it. The temperature of the drying oven is 70 degrees Celsius, the drying time is 12 hours, the temperature in the resistance furnace is 400 degrees Celsius, and the holding time is 4 hours. In step A, a 20-mesh screen is used for screening.

3. The process for preparing a biochar adsorbent loaded with iron ions according to claim 1, wherein: In step B, the pickling solution is a hydrochloric acid solution. The carbon powder obtained in step A is placed in the hydrochloric acid solution and soaked for 10-16 hours. The carbon powder is then washed with ultrapure water and centrifuged more than once. The concentration of the hydrochloric acid solution is 1 mol·L-1, and the carbon powder is soaked in the hydrochloric acid solution for 12 hours.

4. The process for preparing a biochar adsorbent loaded with iron ions according to claim 3, wherein: In step B, the carbon powder is washed with ultrapure water and centrifuged three times, the centrifugal speed is 4000 r·min-1, the centrifugal time is 10 min, and the drying time of the bamboo biochar product obtained by centrifugation is 12 hours, and the drying temperature is 70 degrees Celsius.

5. The process for preparing a biochar adsorbent loaded with iron ions according to claim 1, wherein: In step C, ultrapure water is added to the container, and 3-6g FeSO4.7H2O and 4g-5g Fe2(SO4)3 are weighed and dissolved in 600-1000ml ultrapure water, and stirred to obtain Fe 2+ / Fe 3+ solution.

6. The process for preparing a biochar adsorbent loaded with iron ions according to claim 5, wherein: In step C, 5 g of FeSO4.7H2O and 4.5 g of Fe2(SO4)3 were dissolved in every 800 ml of ultrapure water, and the weight of the added bamboo biochar product was 10 g.

7. The process for preparing a biochar adsorbent loaded with iron ions according to claim 5, wherein: In step C, FeSO4.7H2O and Fe2(SO4)3 are dissolved in ultrapure water to obtain Fe 2+ / Fe 3+ The solution was stirred on a magnetic stirrer for 20 min. 2+ / Fe 3+ The solution was stirred for 0.5 hours.

8. The process for preparing a biochar adsorbent loaded with iron ions according to claim 6, wherein: In step C, the concentration of the NaOH solution is 5 mol·L-1, and the NaOH solution adjusts the pH value of the suspension system to 11.

9. The process for preparing a biochar adsorbent loaded with iron ions according to claim 6, wherein: In step C, the sample was washed with ultrapure water and ethanol respectively and centrifuged three times, the centrifugal speed was 4000 r·min-1, the centrifugal time was 10 min, and the drying time of the biochar adsorbent loaded with iron ions obtained after centrifugation was 12 hours, and the drying temperature was 70 degrees Celsius.

10. A biochar adsorbent loaded with iron ions, characterized by: The invention is prepared according to the preparation process of the biochar adsorbent loaded with iron ions according to any one of claims 1 to 9.

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