A biochar material for remediation of cadmium and tetracycline combined pollution in water bodies and a preparation method and application thereof

Abstract

The present application relates to a kind of for cadmium and tetracycline complex pollution repair in water body biological carbon material and its preparation and application, belong to water pollution repair technical field.It includes steps: (1) take fungus and nightshade after the joint repair cadmium contaminated soil nightshade plant plant tissue, after washing, drying and grinding, obtain nightshade plant tissue powder;(2) nightshade plant tissue powder is pyrolyzed 1-3h under 400-600 ℃, cooling to 20-30 ℃, after grinding, obtain the biological carbon material for cadmium and tetracycline complex pollution repair in water body.The present application first uses fungus and nightshade after the joint repair cadmium contaminated soil nightshade plant plant tissue as the raw material of biological carbon material, realizes the resource utilization of contaminated soil repair plant.Both solve the disposal problem of plant after contaminated soil repair, and avoid the consumption of additional resources, greatly reduce the cost of sewage treatment.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of for cadmium and tetracycline complex pollution repair in water body Biochar material and its preparation and application, belong to water body pollution repair technical field. BACKGROUND

[0002] Antibiotics are often used as growth promoters in animal husbandry, but most of them cannot be adsorbed and are eventually excreted into the environment. Heavy metals are released into the ecosystem through the use of fertilizers, sewage sludge and heavy metal-containing pesticides, making tetracycline (TC) and cadmium (Cd) coexist a common pollution phenomenon in natural water bodies.

[0003] Current research on biochar in the field of pollutant adsorption is mostly limited to single organic pollutants or heavy metals. Chinese patent document CN117046444A discloses a method for repairing arsenic and cadmium complex pollution using layered multi-metal oxide-based magnetic biochar. By mixing biomass raw materials with iron salt solution, pre-magnetic pyrolysis, and using a hydrothermal method to prepare layered multi-metal oxide-based magnetic biochar, the migration rate and bioavailability of arsenic and cadmium are significantly reduced. However, this patent only targets heavy metal contaminated water bodies, and the physicochemical properties of organic matter and heavy metals are quite different, so the repair mechanism is different and cannot be directly applied to heavy metal and antibiotic complex contaminated water bodies. Therefore, there is an urgent need to develop a repair technology suitable for heavy metal and antibiotic complex pollution. SUMMARY

[0004] To overcome the shortcomings of the prior art, the present application provides a kind of for cadmium and tetracycline complex pollution repair in water body Biochar material and its preparation and application.

[0005] The technical solution of the present application is as follows:

[0006] A method for preparing a biochar material for repairing cadmium and tetracycline complex pollution in water bodies, comprising the following steps:

[0007] (1) Take the plant tissue of Solanum nigrum plants after fungal and Solanum nigrum joint repair of cadmium contaminated soil, after washing, drying and grinding, obtain Solanum nigrum plant tissue powder;

[0008] (2) Pyrolyze the Solanum nigrum plant tissue powder at 400-600℃ for 1-3h, cool to 20-30℃, after grinding, obtain the biochar material for repairing cadmium and tetracycline complex pollution in water bodies.

[0009] According to the present application, in step (1), the Solanum nigrum plants after fungal and Solanum nigrum joint repair of cadmium contaminated soil refer to the Solanum nigrum plants after 3 months of joint repair of cadmium contaminated soil by Aspergillus terreus, Mucor circinelloides and Penicillium oxalicum. During the repair process, the three fungi invade the plant roots by producing a large amount of mycelium and interact with the plants to form mycorrhizae.

[0010] According to the application, preferably, in step (1), the plant tissue is Solanum nigrum stem, Solanum nigrum leaf or Solanum nigrum mycorrhiza.

[0011] Further preferably, the plant tissue is Solanum nigrum mycorrhiza.

[0012] According to the application, preferably, in step (2), the Solanum nigrum plant tissue powder is pyrolyzed at 450-550 DEG C for 1.5-2.5 h.

[0013] Further preferably, the Solanum nigrum plant tissue powder is pyrolyzed at 550 DEG C for 2 h.

[0014] A biochar material for remediation of cadmium and tetracycline compound pollution in water bodies is prepared according to the above method.

[0015] Application of the above biochar material in remediation of cadmium and tetracycline compound pollution in water bodies.

[0016] According to the application, preferably, the application method is as follows:

[0017] The biochar material is added to the cadmium and tetracycline compound pollution water body at a ratio of 0.8-1.6 g / L, and mechanical stirring and oscillation are carried out for 20-30 h, so that the biochar is uniformly dispersed in the compound pollution water body and fully reacts with the pollutants.

[0018] The parts not described in detail in the application can be carried out according to the prior art.

[0019] The technical features and beneficial effects of the application are as follows:

[0020] 1. The application first uses the plant tissue of Solanum nigrum plant after fungal and Solanum nigrum combined remediation of cadmium contaminated soil as the raw material of biochar material, realizes the resource utilization of the remediation plant of the contaminated soil, solves the disposal problem of the plant after remediation of the contaminated soil, avoids the consumption of additional resources, and greatly reduces the cost of sewage treatment.

[0021] 2. The biochar material provided by the application, especially the Solanum nigrum mycorrhiza biochar material, has good adsorption performance in cadmium and tetracycline compound pollution water bodies, has strong anti-interference ability and synergistic adsorption ability to compound pollutants. In laboratory adsorption test, the adsorption amount of Cd reaches 1.55 mg / g, and the adsorption amount of TC reaches 20.41 mg / g. In actual water sample adsorption test, the adsorption amount of Cd reaches 1.49 mg / g, and the adsorption amount of TC reaches 17.28 mg / g.

[0022] 3、The application method of the present application is relatively simple to operate, only needs to add the biochar into the cadmium and tetracycline compound contaminated water body according to a certain proportion, carries out oscillation reaction, and finally separates the biochar and the treated water body through centrifugation and filtration. In addition, the nightshade is widely sourced and low in price, which further reduces the preparation cost of the biochar, so that the repair method has good economy and practical application prospect. BRIEF DESCRIPTION OF DRAWINGS

[0023] Figure 1 The adsorption amount of the biochar material of example 1 of the present application to pollutants.

[0024] Figure 2 The scanning electron microscope images and energy spectrum analysis images (EDX) of the biochar material of example 1 of the present application before and after adsorption;

[0025] In the figure, (a) is the scanning electron microscope image of the biochar material of example 1 before adsorption; (b) is the scanning electron microscope image of the biochar material of example 1 after adsorption; (1) is the energy spectrum analysis image of the biochar material of example 1 before adsorption; (2) is the energy spectrum analysis image of the biochar material of example 1 after adsorption.

[0026] Figure 3 The repair effect of the biochar material of example 1 of the present application on actual sewage;

[0027] In the figure, (a) is the Cd adsorption amount result; (b) is the TC adsorption amount result. DETAILED DESCRIPTION

[0028] The present application will be further described below through specific examples and drawings, but is not limited to the scope of the claimed protection. The raw material components used in the examples are all conventional raw materials, and the equipment used is all conventional equipment, which can be obtained from the market.

[0029] The nightshade plant used in the example after the combined repair of cadmium contaminated soil by fungi and nightshade is from the plant greenhouse of the College of Municipal and Environmental Engineering of Shandong Jianzhu University, which is the nightshade plant after 3 months of combined repair of cadmium contaminated soil by Aspergillus terreus, Mucor circinelloides, Penicillium oxalicum and nightshade. During the repair process, the three kinds of fungi invade the plant roots by producing a large number of mycelium, interact with the plants to form mycorrhiza.

[0030] Example 1

[0031] A preparation method of a biochar material for repairing cadmium and tetracycline compound pollution in water body, comprising the following steps:

[0032] (1) Select the fungal and nightshade combined repair of cadmium contaminated soil after nightshade plants, collect the mycorrhizal part of the nightshade plant to ensure the integrity of the sample; After collection, the nightshade mycorrhizae are carefully washed with water, naturally air dried, and then placed in a 110℃ electric heating air drying oven for drying to constant weight;

[0033] Then the dried nightshade mycorrhizae are ground using a high-speed universal grinder to obtain nightshade mycorrhizal powder; The nightshade mycorrhizal powder has a large specific surface area, which is beneficial to the transfer of heat and the progress of the reaction in the subsequent pyrolysis process, and the powdered raw material can also make the prepared biochar more uniform in properties and improve its adsorption performance for Cd and tetracycline;

[0034] (2) Place the nightshade mycorrhizal powder in a 20mL quartz crucible, cover it with a lid and wrap it tightly with tin foil, and place it in a box-type resistance furnace for pyrolysis treatment; The pyrolysis temperature is set to 550℃ and the pyrolysis time is 2h; Under this temperature and time condition, the organic matter in the nightshade mycorrhizae will gradually be converted into biochar; After pyrolysis, turn off the power of the resistance furnace, wait for the temperature in the furnace to naturally drop to room temperature (25℃), take out the crucible, and take out the carbonized nightshade mycorrhizae; Grind the carbonized nightshade mycorrhizae again using a mortar to obtain nightshade mycorrhizal biochar material (RCF); The second grinding can make the biochar particles more delicate and uniform, further improving its specific surface area and adsorption performance.

[0035] Example 2

[0036] A method for preparing a biochar material for repairing cadmium and tetracycline complex pollution in water bodies, the specific steps are the same as in Example 1, except that the plant tissue used in this example is nightshade stem, the pyrolysis temperature in step (2) is set to 500℃, and the product obtained is nightshade stem biochar material (SCF).

[0037] Example 3

[0038] A method for preparing a biochar material for repairing cadmium and tetracycline complex pollution in water bodies, the specific steps are the same as in Example 1, except that the plant tissue used in this example is nightshade leaf, the pyrolysis temperature in step (2) is set to 450℃, and the pyrolysis time is shortened to 1h, and the product obtained is nightshade leaf biochar material (LCF).

[0039] Comparative Example

[0040] A method for preparing nightshade root biochar, the specific preparation method is the same as in Example 1, except that in step (1), only the mycorrhizal part of the nightshade plant after repairing cadmium contaminated soil with nightshade is selected to prepare biochar, and the product obtained is nightshade root biochar (CF) after single nightshade treatment.

[0041] Test Example 1

[0042] The TC and Cd adsorption amounts of the Solanum nigrum mycorrhizal biochar material (RCF), Solanum nigrum stem biochar material (SCF), Solanum nigrum leaf biochar material (LCF) and Solanum nigrum root biochar (CF) prepared in Examples 1-3 after treatment of Solanum nigrum root were determined by simulating TC-Cd composite adsorption experiment of the composite contaminated water body, and the method was as follows:

[0043] 1. A Cd solution with a concentration of 300 mg / L was prepared, and a TC solution with a concentration of 1000 mg / L was prepared. Then 5 mL of the Cd solution and 15 mL of the TC solution were taken into a 500 mL volumetric flask, and deionized water was added for dilution to obtain a simulated composite contaminated water body (500 mL) with a Cd concentration of 3 mg / L and a TC concentration of 30 mg / L.

[0044] 0, 0.5, 1, 2, 3 and 4 mL of the TC stock solution were taken and diluted to 100 mL to obtain TC solutions with gradient concentrations of 0, 5, 10, 20, 30 and 40 mg / L. The absorbance of the sample was measured at 356 nm, and a standard curve was drawn according to the absorbance value.

[0045] 2. 0.02 g of the Solanum nigrum mycorrhizal biochar material (RCF), 0.02 g of the Solanum nigrum stem biochar material (SCF), 0.02 g of the Solanum nigrum leaf biochar material (LCF) and 0.02 g of the Solanum nigrum root biochar (CF) after treatment of Solanum nigrum root were added into centrifuge tubes containing 20 mL of the simulated composite contaminated water body, respectively, for a total of 4 groups. Then the centrifuge tubes were placed in a shaking bed and shaken at 25°C and 160 r / min for 24 h to allow the biochar to fully contact with the pollutants in the water body and undergo adsorption reaction. After the reaction was completed, centrifugation was performed at a speed of 4000 r / min for 30 min, the supernatant was filtered with a filter membrane with a pore size of 0.45 μm, the Cd ion concentration in the filtrate was determined by atomic absorption spectrophotometry, the Cd adsorption amount was calculated according to the detected concentration, the absorbance of the sample was measured at 356 nm by ultraviolet-visible spectrophotometry, and the corresponding TC concentration was calculated according to the standard curve to calculate the TC adsorption amount. The results are shown in Table 1, and the adsorption amount of the Solanum nigrum mycorrhizal biochar material (RCF) to the pollutants is shown in Table 2. Figure 1

[0046] Table 1, Adsorption of biochar in Examples 1-3 to Cd-TC composite pollutants

[0047]

[0048] Table 1 and Table 2 show that the Solanum nigrum mycorrhizal biochar material (RCF) has the best adsorption effect on the pollutants. Figure 1 ​It can be seen that compared with the single nightshade treated nightshade root biochar (CF), the nightshade mycorrhizal biochar material (RCF), the nightshade stem biochar material (SCF) and the nightshade leaf biochar material (LCF) have better adsorption effect on Cd and TC, realizing the resource utilization of the remediation plant of the contaminated soil. It not only solves the disposal problem of the plant after the remediation of the contaminated soil, but also avoids the consumption of additional resources, greatly reducing the cost of sewage treatment.

[0049] Among them, the nightshade mycorrhizal biochar material (RCF) has an adsorption amount of 1.55 mg / g for Cd and 20.41 mg / g for TC in the simulated composite pollution water body with a Cd concentration of 3 mg / L and a TC concentration of 30 mg / L, which is obviously better than the adsorption effect of 1.28 mg / L for Cd and 18.01 mg / g for TC of the nightshade stem biochar material (SCF) and the adsorption effect of 1.41 mg / L for Cd and 17.77 mg / g for TC of the nightshade leaf biochar material (LCF). This is because during the formation of mycorrhizae, the three fungi invade the plant root system by producing a large number of hyphae, shuttle in the plant root tissue, and after pyrolysis into biochar material, a large number of pores are formed at the original hyphae position, so that the mycorrhizal biochar material has larger porosity, and thus has better adsorption effect.

[0050] 3. Scanning electron microscopy observation and energy spectrum analysis were performed on the nightshade mycorrhizal biochar material (RCF) before and after adsorption, and the results are shown in Figure 2

[0051] As can be seen from Figure 2 , the surface of the nightshade mycorrhizal biochar material (RCF) before adsorption presents a honeycomb-like porous structure with a pore size distribution of 1-5 μm, the inner wall of the pore is rough, rich in oxygen-containing functional groups such as hydroxyl (-OH) and carboxyl (-COOH), the main elements are C (75.3%), O (18.2%), K (3.1%) and Ca (2.4%), and there is no Cd and Cl signal. After adsorbing TC-Cd, Cd particulate matter and TC flocculent matter exist in the pores of the nightshade mycorrhizal biochar material (RCF) at the same time, forming a multi-layer adsorption structure, and cracks with a depth of 5-10 μm appear on the surface, which may be caused by the complexation of cadmium ions and functional groups leading to structural expansion. The contents of Cd (6.2%) and Cl (2.3%) increase significantly, indicating that the TC molecules (containing Cl and N) are successfully adsorbed by the nightshade mycorrhizal biochar material (RCF).

[0052] Test Example 2

[0053] In the TC-Cd composite adsorption experiment in the actual sewage, the adsorption amounts of TC and Cd by the nightshade mycorrhizal biochar material (RCF) prepared in Example 1 were determined, and the method was as follows:

[0054] ​1. Cd solution with a concentration of 300 mg / L was prepared, and TC solution with a concentration of 1000 mg / L was prepared.

[0055] 0.1 mL of Cd solution and TC solution was added to a centrifuge tube, and then the centrifuge tube was filled with lake water, middle water, river water and tap water to 20 mL, respectively, to obtain four kinds of compound contaminated water bodies (20 mL).

[0056] 2. 0.02 g of Solanum nigrum mycorrhizal biochar material (RCF) was added to the centrifuge tube containing 20 mL of compound contaminated water body, and then the centrifuge tube was placed in a shaking bed for oscillation at 25℃ and 160 r / min for 24 h, so that the biochar was fully contacted with the pollutants in the water body and adsorption reaction occurred; after the reaction was completed, centrifugation was carried out at a speed of 4000 r / min for 30 min, the supernatant was filtered with a filter membrane with a pore size of 0.45 μm, the concentration of Cd ions in the filtrate was determined by atomic absorption spectrophotometry, and the adsorption amount of Cd was calculated according to the detected concentration; the absorbance of the sample at 356 nm was determined by ultraviolet visible spectrophotometer, and the corresponding TC concentration was calculated according to the standard curve, and the adsorption amount of TC was calculated, and the results are shown in Figure 3

[0057] As can be seen from Figure 3 , in the four different cadmium and tetracycline compound contaminated water bodies, the adsorption effect of Solanum nigrum mycorrhizal biochar material on Cd was the best in lake water, and the adsorption amount reached 1.49 mg / g, and the adsorption effect was the worst in middle water, and the adsorption amount was only 1.30 mg / g. At the same time, the adsorption effect of Solanum nigrum mycorrhizal biochar material on TC was the best in lake water, and the adsorption effect of tap water simulated sewage was the second, and the adsorption amounts were 17.28 mg / g and 16.99 mg / g, respectively. It shows that Solanum nigrum mycorrhizal biochar material (RCF) also has good adsorption performance in cadmium and tetracycline compound contaminated actual water body, and has strong anti-interference ability and synergistic adsorption ability to compound pollutants.

[0058] The above described is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.​

Claims

1. A method for preparing a biochar material for remediation of cadmium and tetracycline combined pollution in water bodies, characterized in that, The method comprises the following steps: (1) obtaining Solanum nigrum L. plant tissue powder by cleaning, drying and grinding Solanum nigrum L. plant tissue after fungi and Solanum nigrum L. are combined to repair cadmium contaminated soil; The fungi and Solanum nigrum L. plant tissue after repairing cadmium contaminated soil refer to Solanum nigrum L. plant tissue after being repaired by Aspergillus terreus, Mucor circinelloides and Penicillium oxalicum for 3 months; the plant tissue is Solanum nigrum L. stem, Solanum nigrum L. leaf or Solanum nigrum L. mycorrhiza; (2) pyrolyzing the Solanum nigrum L. plant tissue powder at 400-600 ℃ for 1-3 h, cooling to 20-30 ℃, and grinding to obtain a biochar material for repairing cadmium and tetracycline compound contaminated water.

2. The production method according to claim 1, wherein In step (2), the plant tissue is Solanum nigrum L. mycorrhiza.

3. The production method according to claim 1, wherein In step (2), the Solanum nigrum L. plant tissue powder is pyrolyzed at 450-550 ℃ for 1.5-2.5 h.

4. The production method according to claim 3, wherein The Solanum nigrum L. plant tissue powder is pyrolyzed at 550 ℃ for 2 h.

5. A biochar material for remediation of cadmium and tetracycline combined pollution in water bodies, characterized in that, The biochar material is prepared by the method according to any one of claims 1-4.

6. The biochar material of claim 5 is used for repairing cadmium and tetracycline compound contaminated water.

7. Use according to claim 6, wherein The application method is as follows: The biochar material is added to cadmium and tetracycline compound contaminated water at a ratio of 0.8-1.6 g / L, and mechanical stirring and oscillation are performed for 20-30 h, so that the biochar is uniformly dispersed in the compound contaminated water and fully reacts with the pollutants.

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