Preparation method and application of invasive plant horseweed herb biochar

Abstract

The invention discloses a preparation method and application of invasive plant horseweed herb biochar. A preparation method of invasive plant horseweed herb biochar comprises the following steps: (1) collecting roots, stems and leaves of horseweed herb, washing with distilled water, drying, and grinding into powder; and (2) respectively carbonizing the crushed roots, stems and leaves of the horseweed herb in an environment of 450 DEG C so as to prepare the finished product activated carbon. The invention discloses application of biochar prepared from an invasive plant horseweed herb in the field of wastewater treatment. Especially, the invasive plant horseweed herb leaf charcoal part can efficiently adsorb and remove chromium ions in the wastewater, and has important significance for improving the resource utilization of invasive plants and enhancing the economic treatment capacity of the wastewater.

Description

Technical Field

[0001] The invention relates to the preparation of biochar of an invasive plant, Erigeron candidum.

[0002] The invention relates to resource utilization of invasive plants.

[0003] The present invention also relates to the application of the above biochar in the treatment of chromium-containing heavy metal wastewater. Background Art

[0004] The ecological and environmental changes caused by the invasion of alien plants have become one of the major global environmental problems. The main reason is that invasive plants will have a profound impact on the structure and function of local ecosystems, including reducing the biodiversity of local plant communities, weakening the stability of plant communities, increasing their susceptibility to invasion, changing the pH value and nutrient cycle of the soil, and thus causing disorders in the function and structure of local plant communities, thereby triggering a series of ecological risks and posing a threat to human health and socioeconomic development.

[0005] At present, the research on Asteraceae invasion mainly focuses on prevention mechanism and invasion mechanism, with resource development and utilization as an important supplement. However, after more than half a century of in-depth research, although initial construction has been made in invasion mechanism and physical, biological and chemical control systems, there are still few cases of completely eliminating specific invasive plants or successfully implementing invasion control on a large scale and achieving significant control effects. Therefore, on the basis of existing research, it is of great significance to further deepen the development and utilization of invasive plants as resources.

[0006] At present, invasive plants have received extensive attention in the research fields of resource utilization, such as pharmaceutical processing, bio-inhibitor production, feed or fertilizer processing. However, there are relatively few studies on the use of invasive plants to prepare biochar and its resource application. At the same time, compared with the preparation technology of traditional biochar, the production cost of biochar is lower, and it has excellent adsorption properties and catalytic activity, which is suitable for water treatment, waste gas purification, soil remediation and other fields. Therefore, this invention is dedicated to the preparation of biochar using the leaves of the invasive plant Erigeron cantoniensis, and applying it to the field of environmental protection materials to remove pollutants such as heavy metals in wastewater, providing an innovative solution for the resource utilization of invasive plants and the economic treatment of heavy metal wastewater. Summary of the invention

[0007] The purpose of the present invention is to utilize invasive plants as resources, and to provide a preparation method and application of biochar of the invasive plant Erigeron candidum.

[0008] The biochar preparation scheme adopted in the present invention is:

[0009] 1. A method for preparing biochar of an invasive plant, Erigeron candidum, by the following steps:

[0010] (1) collecting roots, stems and leaves of Erigeron candidum respectively, washing, air-drying and drying them, and then crushing them;

[0011] (2) The sample in step (1) is carbonized at 450° C. to obtain primary biochar;

[0012] (3) The primary biochar in step (2) is sieved through a 75-mesh sieve to obtain finished biochar.

[0013] In step (1), the length of the collected root and stem samples is 3-5 cm.

[0014] In step (1), the rinsing method is: the roots, stems and leaves are washed with tap water for 2 to 3 times respectively, and then rinsed with distilled water for 2 to 3 times.

[0015] In step (1), the air-drying and baking method is: placing the roots, stems and leaves in the sun to dry, and then baking at 85° C. for 24 hours to constant weight.

[0016] In step (1), the crushing number is 75 meshes.

[0017] In step (2), the carbonization time is 2 hours.

[0018] The invention discloses an application of biochar prepared from the invasive plant Erigeron candidum in wastewater treatment.

[0019] The wastewater is chromium-containing wastewater.

[0020] The wastewater oscillation adsorption time is 12 hours.

[0021] The focus is on the preparation and application of biochar from the leaves of the invasive plant Erigeron candidum.

[0022] The core feature of the present invention is that the roots, stems and leaves of the invasive plant Erigeron edulis are finely prepared for biochar, and the unique effects of different parts of Erigeron edulis in wastewater treatment are emphasized, thereby realizing the comprehensive resource transformation of underground and aboveground parts. The present invention successfully realizes the comprehensive development and utilization of the whole plant of the invasive plant Erigeron edulis, especially the carbonization utilization can be carried out by direct collection and simple treatment, and its resource utilization efficiency is significant, and the preparation process of biochar is simple, efficient and economical. In view of the wide range of invasion of Erigeron edulis and its easy accessibility, using it as a raw material for the preparation of biochar not only embodies the principle of economic saving, but also highlights the concept of green environmental protection and eco-friendliness. In particular, the prepared biochar, especially the one using Erigeron edulis leaves as raw materials, shows excellent adsorption capacity for chromium, indicating its broad prospects in the field of industrial application and deep excavation of social value. In addition, the method provided by the present invention has a high degree of universality and can be flexibly applied to the preparation process of biochar of various invasive plants. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Attached Figure 1 This is a scanning electron microscope image of the biochar from the roots, stems, and leaves of the invasive plant Erigeron candidum;

[0024] Attached Figure 2 This is a diagram showing the effect of biochar in the embodiment on the adsorption of chromium ions under different pH conditions;

[0025] Attached Figure 3 This is a diagram showing the effect of different amounts of biochar added in the example on the adsorption and removal of chromium ions under pH = 2. DETAILED DESCRIPTION

[0026] The present invention is based on the preparation of biochar, and carries out comprehensive resource utilization of the ecologically harmful invasive plant Erigeron fasciatus. The specific invention name is: a preparation method and application of biochar of the invasive plant Erigeron fasciatus, and the biochar is prepared by the following steps:

[0027] (1) collecting roots, stems and leaves of Erigeron candidum respectively, washing, air-drying and drying them, and then crushing them;

[0028] (2) The sample in step (1) is carbonized at 450° C. to obtain primary biochar;

[0029] (3) The primary biochar in step (2) is sieved through a 75-mesh sieve to obtain finished biochar.

[0030] In step (1), the roots, stems and leaves of the invasive plant Erigeron candidum are collected in the field, and the collected root and stem samples are cut into pieces with a length of 3-5 cm. Subsequently, the roots, stems and leaves are washed 2-3 times with tap water, and then rinsed 2-3 times with distilled water. Subsequently, the roots, stems and leaves are placed in the sun to dry naturally. After drying, the roots, stems and leaves are placed in an oven at 85° C. and dried for 24 hours to constant weight. The dried roots, stems and leaves of the invasive plant Erigeron candidum are crushed by a pulverizer and passed through a 75-mesh sieve to obtain root, stem and leaf samples.

[0031] In step (2), the root, stem and leaf samples were carbonized in a muffle furnace at 450° C. for 2 h to obtain primary biochar.

[0032] In step (3), the obtained primary biochar is again sieved through a 75-mesh sieve to obtain finished-grade biochar.

[0033] The application of biochar prepared from the invasive plant Erigeron candidum in wastewater treatment, wherein the wastewater selected for the application is chromium-containing wastewater, and the application details of the present invention are described in detail through the following application examples.

[0034] Application examples:

[0035] (1) Biochar structure characterization: Appendix Figure 1The scanning electron microscope image of the biochar (GBS) prepared by using the roots, stems and leaves of the invasive plant Erigeron candidum as raw materials is shown in the present invention. The image clearly shows that the surface of the biochar is densely covered with numerous pore structures of different sizes. This feature significantly increases the specific surface area of ​​the material, thereby enhancing its adsorption capacity. In particular, the biochar prepared from the leaves of the invasive plant Erigeron candidum has smaller particles and is more evenly distributed, followed by the biochar from the stems of Erigeron candidum, and then the biochar from the roots of Erigeron candidum.

[0036] (2) Application of chromium adsorption:

[0037] A. Drawing of standard curve: Refer to the national standard method (GB / T 7466-87), the determination method of hexavalent chromium - diphenylcarbazide spectrophotometry to draw the standard curve.

[0038] B. Determination of the optimum pH: Take 15 50mL centrifuge tubes, add 40mL of chromium ion solution with a concentration of 100mg / L to each 50mL centrifuge tube, divide the 15 centrifuge tubes into three groups, add 20mg of root biochar to each centrifuge tube in the first group, add 20mg of stem biochar to each centrifuge tube in the second group, and add 20mg of leaf biochar to each centrifuge tube in the third group. Use 0.1molL NaOH solution and 0.1molL HCl solution to adjust the pH value of each group to 2, 3, 4, 5, and 6 in turn, and place all test samples in a constant temperature oscillator for 12h in the dark. Then, filter with a 0.22μm water filter membrane to determine the hexavalent chromium content in the filtrate.

[0039] C. Determination of biochar dosage: Prepare 27 50mL centrifuge tubes divided into three groups: roots, stems, and leaves, with 9 centrifuge tubes in each group. The amount of biochar added to each group is 30mg, 60mg, and 90mg, respectively. Add 40mL of 100mg / L hexavalent chromium solution to each centrifuge tube, adjust the pH of all centrifuge tubes to the optimal pH value with 0.1molL NaOH solution and 0.1molL HCl, and place all test samples in a constant temperature oscillator for 12 hours in the dark. Then, filter with a 0.22μm water filter membrane to determine the hexavalent chromium content in the filtrate.

[0040] Attached Figure 2 The effect of biochar from the roots, stems and leaves of the invasive plant Erigeron candidum on the adsorption of chromium ions under different pH conditions is shown. Figure 2 It can be seen that the optimal pH value for the adsorption effect and removal rate of biochar from the roots, stems and leaves of the invasive plant Erigeron cantoniensis is 2.

[0041] Attached Figure 3 The graph shows the effect of adding different amounts of biochar to the roots, stems and leaves of the invasive plant Erigeron candidum on the adsorption and removal of chromium ions under pH = 2. Figure 3It can be seen that the adsorption and removal rate of biochar of the invasive plant Erigeron candidum root, stem and leaf are in the order of leaf>stem>root. When 30mg, 60mg and 90mg of root biochar were added, the adsorption amount was 0.29mg / g, 1.66mg / g and 4.32mg / g, respectively, and the removal rates were 0.27%, 3.07% and 11.98%, respectively; when 30mg, 60mg and 90mg of stem biochar were added, the adsorption amount was 11.33mg / g, 10.43mg / g and 6.98mg / g, respectively, and the removal rates were 10.47%, 19.27% ​​and 19.34%, respectively; when 30mg, 60mg and 90mg of leaf biochar were added, the adsorption amount was 45.70mg / g, 39.49mg / g and 32.30mg / g, respectively, and the removal rates were 42.23%, 72.98% and 89.54%, respectively. This indicates that the invasive plant Erigeron candidum biochar of this invention, especially the Erigeron candidum leaf biochar, has a higher adsorption capacity and removal rate for hexavalent chromium in wastewater.

Claims

1. A method for preparing biochar of an invasive plant, Erigeron candidum, by the following steps: (1) collecting roots, stems and leaves of Erigeron candidum respectively, washing, air-drying and drying them, and then crushing them; (2) The sample in step (1) is carbonized at 450° C. to obtain primary biochar; (3) The primary biochar in step (2) is sieved through a 75-mesh sieve to obtain finished biochar.

2. The method for preparing biochar of the invasive plant Erigeron candidum according to claim 1, wherein the length of the root and stem samples collected in step (1) is 3-5 cm.

3. The method for preparing biochar of the invasive plant Erigeron candidum according to claim 1, wherein the rinsing method in step (1) is: washing the roots, stems and leaves with tap water for 2 to 3 times respectively, and then rinsing with distilled water for 2 to 3 times.

4. The method for preparing biochar of the invasive plant Erigeron candidum according to claim 1, wherein the air-drying and baking method in step (1) is: placing the roots, stems and leaves in the sun to dry, and then baking at 85°C for 24 hours to constant weight.

5. The method for preparing biochar of the invasive plant Erigeron candidum according to claim 1, wherein the pulverization number in step (1) is 75 meshes.

6. The method for preparing biochar of the invasive plant Erigeron candidum according to claim 1, wherein the carbonization time in step (2) is 2 hours.

7. Use of biochar prepared from the invasive plant Erigeron candidum according to any one of claims 1 to 6 in wastewater treatment.

8. Use of the biochar prepared from the invasive plant Erigeron candidum in wastewater treatment according to claim 7, wherein the wastewater is chromium-containing wastewater.

9. Use of the biochar prepared from the invasive plant Erigeron candidum in wastewater treatment according to claim 8, wherein the water treatment pH is 2.

0.

10. Use of the biochar prepared from the invasive plant Erigeron candidum in wastewater treatment according to claim 8, wherein the wastewater oscillation adsorption time is 12 hours.

11. The preparation method and application of biochar of the invasive plant Erigeron candidum as described in claims 1 to 10, wherein the core of the claim is the preparation and application of biochar of Erigeron candidum leaves.

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