Application of constructed wetland in removal of sulfonamide antibiotics and resistance genes in water body

Abstract

The invention discloses an application of a constructed wetland in removal of sulfonamide antibiotics and resistance genes in a water body, and belongs to the technical field of constructed wetlands. The application comprises the following steps: opening a water inlet pipe and a water outlet pipe to enable the constructed wetland to start running; a water body containing sulfonamide antibiotics and resistance genes enters the constructed wetland through a water inlet pipeline, the hydraulic retention time is 7 days, and the concentration of the sulfonamide antibiotics and the absolute abundance of the antibiotic resistance genes in the water body are controlled; the whole operation cycle is carried out at the temperature of 22 + / -4 DEG C. The constructed wetland with the modified charcoal composite matrix has a remarkable removal effect on sulfonamide antibiotics and antibiotic resistance genes, and meanwhile, the constructed wetland has a relatively excellent purification effect on the water quality of a water body.

Description

Technical Field

[0001] The present invention relates to the technical field of constructed wetlands, and more particularly to an application of a constructed wetland in removing sulfonamide antibiotics and resistance genes from water bodies. Background Art

[0002] With the rapid development of social economy and the improvement of people's living standards, a large amount of wastewater rich in nutrient elements is directly discharged into natural water bodies, thus triggering global water resource problems such as water shortage and water eutrophication. At present, most of the water pollution problems in China come from industrial, domestic and agricultural sewage, among which the discharge of domestic sewage is particularly prominent, which poses a serious threat to the overall water environment in China.

[0003] Sulfonamide antibiotics are one of the most produced and used antibiotics in the Chinese market, and are widely used in animal husbandry, aquaculture and medicine. A part of sulfonamide antibiotics cannot be absorbed and metabolized by the animal intestine, and are discharged into water bodies through various channels with feces and domestic wastewater, causing antibiotic pollution of water bodies. Sulfonamide antibiotics have a long half-life and can stably exist in a typical water environment. The remaining antibiotics will be transferred and enriched into animals and plants (such as human food) through various migration and transformation pathways, thus endangering human health. Sewage treatment plants are not good at removing antibiotics such as sulfonamide antibiotics. The effluent of sewage treatment plants is a frequent detection site for trace pollutants such as antibiotics, antibiotic resistance genes, and personal care products. Sulfonamide antibiotics are mostly highly persistent in the environment. The selective pressure of residual antibiotics in the environment will induce microorganisms to develop tolerance to antibiotics, and then lead to the proliferation and increase in the abundance of resistance genes in microorganisms. Bacterial drug resistance is a complex process. The abundance of ARGs is related not only to the concentration of antibiotics but also to the abundance of mobile elements. Antibiotic resistance genes in water bodies are spread among microbial populations through vertical and horizontal transfer, and mobile elements such as plasmids, integrons and transposons participate in the horizontal transfer of ARGs. The emergence, spread of antibiotic-tolerant bacteria and the pollution of antibiotic resistance genes are serious public health problems worldwide. Antibiotic resistance genes have been found in animal bodies and agricultural soils, and it has been found that the abundance of sul genes in the soil in Northeast China is the highest. The presence of sul will weaken the therapeutic effect of drugs on the infection of human and animal pathogens. The emergence of these phenomena has caused global public health risks and environmental ecological risks

[0004] Traditional matrix artificial wetland technology has defects such as poor matrix adsorption effect and low carbon content when treating domestic sewage. Biochar has structural advantages such as rich porosity and excellent BET specific surface area. It is more effective in removing pollutants when applied to artificial wetland matrix. In the process of making biochar, high-temperature pyrolysis and carbonization will produce a large amount of ash, which will block the pores of biochar and seriously limit the adsorption performance of biochar. In addition, too much ash will also block the artificial wetland and reduce its service life. Modification of biochar can improve the adsorption capacity of biochar and optimize the structural advantages of biochar. After the biochar is treated with NaOH, the pore structure is more complete and clear, the ash is significantly removed, and the specific surface area and pore volume are increased. In addition, the content of C, H, O, and N changes, the oxygen-containing functional groups such as -OH and -COOH increase, and the aromaticity and hydrophobicity decrease.

[0005] Therefore, how to develop an artificial wetland for use in removing sulfonamide antibiotics and resistance genes in water bodies is an urgent problem that technicians in this field need to solve. Summary of the invention

[0006] In view of this, the present invention provides an application of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water.

[0007] In order to achieve the above object, the present invention adopts the following technical solution:

[0008] An application of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water bodies, the artificial wetland comprising an artificial wetland pool, a water inlet pipeline and wetland plants, the filler layers of the artificial wetland pool comprising a soft fine sand layer, a quartz sand layer, a zeolite and modified biochar mixed layer and a gravel layer from top to bottom, and the wetland plant planted in the quartz sand layer is Siberian iris;

[0009] The zeolite and modified biochar mixed layer is obtained by mixing modified biochar and zeolite, the volume of the modified biochar is 25% of the volume of the zeolite, and the modified biochar is sodium hydroxide modified biochar;

[0010] The water inlet pipeline passes through the packing layer of the artificial wetland pool, and the water outlet of the water inlet pipeline is located in the quartz sand layer. The water inlet pipeline outside the artificial wetland pool is sequentially installed with a liquid valve and a liquid flow meter. The bottom of the side wall of the artificial wetland pool is provided with a water outlet pipe on one side and a sampling tube on the other side;

[0011] The water inlet and outlet pipes were opened to start the operation of the artificial wetland. The water containing sulfonamide antibiotics and resistance genes entered the artificial wetland through the water inlet pipe. The hydraulic retention time was 7 days. The temperature of the entire operation cycle was carried out at 22±4℃.

[0012] The concentrations of sulfonamide antibiotics in water bodies are: sulfadiazine 5.80-5.83μg / L, sulfapyridine 5.50-5.51μg / L, sulfamethoxazole 6.66-6.68μg / L, sulfamethoxazole 5.39-5.40μg / L, sulfadimethoxine 5.26-5.27μg / L, sulfamethoxazole 6.28-6.29μg / L, sulfamethoxazole 4.54-4.55μg / L, sulfamethoxazole 6.29-6.30μg / L;

[0013] The absolute abundance of antibiotic resistance genes in water bodies is:

[0014] 16s rRNA 9.74×10 4 -2.48×10 5 copies / mL, intI1 2.37×10 4 -4.15×10 4 copies / mL,sul1 2.61×10 4 -4.55×10 4 copies / mL,sul2 1.48×10 4 -2.53×10 4 copies / mL;

[0015] Influent load: NH 4 + -N: 19.43-21.83mg∙L -1 , NO 2 - -N: 0.04-0.37mg∙L -1 , NO 3 - -N: 2.20-5.80mg∙L -1 , TN: 23.57-27.93 mg∙L -1 , TP: 0.99-1.1mg∙L -1 , COD: 73.67-80mg∙L -1 .

[0016] Beneficial effects of the present invention:

[0017] Alkali-modified biochar and zeolite are mixed in a specific ratio as a composite matrix of artificial wetlands to improve the removal capacity of artificial wetlands for sulfonamide antibiotics (SD: sulfadiazine, SPD: sulfapyridine, SMX: sulfamethoxazole, SMD: sulfamethoxazole, SM2: sulfadimethoxine, SMT: sulfamethoxazole, SM: sulfamethoxazole, SPZ: sulfamethoxazole) and resistance genes (16s rRNA, intI1, sul1 and sul2). Changing the influent load of artificial wetlands will affect the growth and development of microorganisms and plants, effectively improve the activity of microorganisms and plants, and enhance the removal effect of artificial wetlands.

[0018] Wetland plants selected Siberian iris have a well-developed root system, so Siberian iris can better absorb pollutants over a larger area. In addition, Siberian iris has strong stress resistance, which enables it to better adapt to the environment, thereby providing a stable growth environment for microorganisms, making artificial wetlands have a positive effect on the removal of sulfonamide antibiotics and antibiotic resistance genes. Moreover, the presence of plants can increase nitrogen removal and reduce the competitive effect with sulfonamide antibiotics and antibiotic resistance genes.

[0019] Furthermore, the height of the soft fine sand layer is 1 cm, the height of the quartz sand layer is 10 cm, the height of the zeolite and modified biochar mixed layer is 40 cm, and the height of the gravel layer is 5 cm.

[0020] Furthermore, the particle size of the quartz sand is 3-5 cm.

[0021] Furthermore, the method for preparing the modified biochar comprises the following steps:

[0022] Corn stalks were chopped and pyrolyzed under nitrogen. The pyrolysis products were soaked and rinsed, the ash on the surface was removed, and the products were dried to constant weight to obtain biochar. The biochar was mixed with a concentration of 0.1 mol∙L -1 The mixture is mixed evenly with sodium hydroxide solution for modification, washed to neutrality, and dried for later use.

[0023] Beneficial effects of adopting the above further technical solution: Corn straw, as a rich and low-cost biomass, is widely distributed in China, and it is a rich raw material for preparing straw biochar. Corn straw conversion into biochar not only helps to achieve carbon fixation and energy saving, but also realizes multi-level resource utilization, which is considered to be an effective way to realize straw resource utilization. The carbon element contained in corn straw reaches more than 40%, providing a high-quality material basis for the preparation of biochar.

[0024] Furthermore, the method for preparing the modified biochar comprises the following steps:

[0025] Corn stalks were cut into 5-10 cm lengths and pyrolyzed under nitrogen conditions at a heating rate of 10 °C min -1 The pyrolysis temperature was 450±25℃, the pyrolysis time was 2.0h, the pyrolysis product was soaked and rinsed, the ash on the surface was removed, and the product was dried at 65℃ to constant weight to obtain biochar. The biochar and the concentration of 0.1 mol∙L -1 The modified product was mixed evenly with sodium hydroxide solution for 24 hours, washed until neutral, and dried at 100°C for later use.

[0026] Furthermore, the particle size of the zeolite is ≤2 mm.

[0027] Furthermore, the planting density of the above-mentioned Siberian iris is 4 plants / m 2 .

[0028] Furthermore, the artificial wetland pool is made of plexiglass and is cylindrical in shape with a diameter of 21 cm and a height of 65 cm. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 The absolute abundance of 16S rRNA and target ARGs in the inlet and outlet water of the BCW and NBCW constructed wetland systems. Figure a: Absolute abundance of 16S rRNA in the inlet and outlet water; Figure b: Absolute abundance of target ARGs in the inlet and outlet water; Figure c: Log value of the removal of target ARGs by the constructed wetland system, C i is the absolute abundance of genes in the influent, C e is the absolute abundance of genes in the effluent; d: the log value of the total ARGs removed in the artificial wetland, C i is the absolute abundance of genes in the influent, C e is the absolute abundance of genes in the outlet water.

[0030] Figure 2 The absolute abundance of 16S rRNA and target ARGs in the matrix and plants of BCW and NBCW artificial wetlands. Figure a: Absolute abundance of 16S rRNA in the matrix and plants; Figure b: Absolute abundance of target ARGs in the matrix; Figure c: Absolute abundance of target ARGs in plant roots; Figure d: Absolute abundance of target ARGs in plant stems and leaves.

[0031] Figure 3 Figure 2 shows the removal of sulfonamide antibiotics by BCW and NBCW constructed wetlands. Figure a: effluent concentration; Figure b: removal rate (SD: sulfadiazine, SPD: sulfapyridine, SMX: sulfamethoxazole, SMD: sulfamethoxazole, SM2: sulfadimethoxine, SMT: sulfamethoxazole, SM: sulfamethoxazole, SPZ: sulfamethoxazole).

[0032] Figure 4The absolute abundance of 16S rRNA and target ARGs in the inlet and outlet water of NBCW1, NBCW2 and NBCW3 artificial wetland systems. (a) The absolute abundance of 16S rRNA in the inlet and outlet water; (b) The absolute abundance of target ARGs in the inlet and outlet water; (c) The log value of the removal of target ARGs by the artificial wetland system, C i is the absolute abundance of genes in the influent, C e is the absolute abundance of genes in the effluent; d: the log value of the total ARGs removed in the artificial wetland, C i is the absolute abundance of genes in the influent, C e is the absolute abundance of genes in the outlet water.

[0033] Figure 5 The absolute abundance of target ARGs in the matrix and plants of artificial wetlands of NBCW1, NBCW2 and NBCW3. Figure a: Absolute abundance of 16s rRNA in the matrix and plants; Figure b: Absolute abundance of target ARGs in the matrix; Figure c: Absolute abundance of target ARGs in plant roots; Figure d: Absolute abundance of target ARGs in plant stems and leaves.

[0034] Figure 6 Figure 2. Removal of sulfonamide antibiotics by constructed wetlands of NBCW1, NBCW2 and NBCW3. Figure a: effluent concentration; Figure b: removal rate (SD: sulfadiazine, SPD: sulfapyridine, SMX: sulfamethoxazole, SMD: sulfamethoxazole, SM2: sulfadimethoxine, SMT: sulfamethoxazole, SM: sulfamethoxazole, SPZ: sulfamethoxazole).

[0035] Figure 7 This is a schematic diagram of the structure of an artificial wetland with a plant composite matrix under low temperature according to the present invention.

[0036] Among them, 1-artificial wetland pool, 2-soft fine sand layer, 3-quartz sand layer, 4-zeolite and modified biochar mixed layer, 5-gravel layer, 6-water inlet pipeline, 7-liquid valve, 8-liquid flow meter, 9-sampling tube, 10-outlet pipe, 11-wetland plants. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Example 1

[0039] The artificial wetland, denoted as NBCW2, includes an artificial wetland pool 1, a water inlet pipeline 6 and wetland plants 11. The filler layers of the artificial wetland pool 1 include a soft fine sand layer 2, a quartz sand layer 3, a zeolite and modified biochar mixed layer 4 and a gravel layer 5 from top to bottom. The wetland plant 11 planted in the quartz sand layer 3 is Iris siberia. The planting density of Iris siberia is 4 plants / m 2 The height of the soft fine sand layer 2 is 1 cm, the height of the quartz sand layer 3 is 9 cm, the height of the zeolite and modified biochar mixed layer 4 is 40 cm, and the height of the gravel layer 5 is 5 cm. The particle size of the quartz sand is 3-5 cm. The particle size of the zeolite is ≤2 mm. The artificial wetland pool 1 is made of organic glass and is cylindrical in shape with a diameter of 21 cm and a height of 65 cm.

[0040] The zeolite and modified biochar mixed layer 4 is obtained by mixing modified biochar and zeolite, the volume of the modified biochar is 25% of the volume of the zeolite, and the modified biochar is sodium hydroxide modified biochar; the preparation method of the modified biochar comprises the following steps: cutting corn stalks into 5-10 cm lengths, pyrolyzing under nitrogen conditions, and heating at a rate of 10°C·min -1 The pyrolysis temperature was 450±25℃, the pyrolysis time was 2.0h, the pyrolysis product was soaked and rinsed, the ash on the surface was removed, and the product was dried at 65℃ to constant weight to obtain biochar. The biochar and the concentration of 0.1mol∙L -1 The modified product was mixed evenly with sodium hydroxide solution for 24 hours, washed until neutral, and dried at 100°C for later use.

[0041] The water inlet pipe 6 passes through the packing layer of the artificial wetland pool 1, and the water outlet of the water inlet pipe 6 is located in the quartz sand layer 3. A liquid valve 7 and a liquid flow meter 8 are installed in sequence on the water inlet pipe 6 outside the artificial wetland pool 1. A water outlet pipe 10 is provided on one side of the bottom of the side wall of the artificial wetland pool 1, and a sampling tube 9 is provided on the other side.

[0042] The inlet and outlet pipes were opened to start the operation of the artificial wetland. The water containing sulfonamide antibiotics and resistance genes entered the artificial wetland through the inlet pipe. The hydraulic retention time was 7 days, the effective volume of the artificial wetland was 7L, and the hydraulic load was 0.0531 m 3 / m 2 The whole operation cycle is carried out at a temperature of 22±4℃.

[0043] The concentration of sulfonamide antibiotics in water, the absolute abundance of antibiotic resistance genes and the influent load were tested three times. The test results of each indicator in the three tests ranged from:

[0044] The concentrations of sulfonamide antibiotics in water bodies are: sulfadiazine 5.80-5.83μg / L, sulfapyridine 5.50-5.51μg / L, sulfamethoxazole 6.66-6.68μg / L, sulfamethoxazole 5.39-5.40μg / L, sulfadimethoxine 5.26-5.27μg / L, sulfamethoxazole 6.28-6.29μg / L, sulfamethoxazole 4.54-4.55μg / L, sulfamethoxazole 6.29-6.30μg / L;

[0045] The absolute abundance of antibiotic resistance genes in water bodies is:

[0046] 16s rRNA 9.74×10 4 -2.48×10 5 copies / mL, intI1 2.37×10 4 -4.15×10 4 copies / mL,sul1 2.61×10 4 -4.55×10 4 copies / mL,sul2 1.48×10 4 -2.53×10 4 copies / mL;

[0047] Influent load: NH 4 + -N: 19.43-21.83mg∙L -1 , NO 2 - -N: 0.04-0.37mg∙L -1 , NO 3 - -N: 2.20-5.80mg∙L -1 , TN: 23.57-27.93 mg∙L -1 , TP: 0.99-1.1mg∙L -1 , COD: 73.67-80mg∙L -1 .

[0048] The average values ​​of the three test results for each indicator are:

[0049] The concentration of sulfonamide antibiotics in water is:

[0050] The inlet concentrations of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were 5.82 μg / L, 5.50 μg / L, 6.67 μg / L, 5.40 μg / L, 5.26 μg / L, 6.28 μg / L, 4.54 μg / L, and 6.29 μg / L, respectively;

[0051] The absolute abundance of antibiotic resistance genes in water bodies is:

[0052] 16s rRNA 1.96×10 5 copies / mL, intI1 3.12×10 4 copies / mL, sul1 3.50×10 4 copies / mL and sul2 1.92×10 4 copies / mL;

[0053] Influent load: NH 4 + -N: 20.51 mg∙L -1 , NO 2 - -N: 0.22 mg∙L -1 , NO 3 - -N: 3.78 mg∙L -1 , TN: 25.49 mg∙L -1 , TP: 1.05 mg∙L -1 , COD: 75.88mg∙L -1 .

[0054] Comparative Example 1

[0055] The artificial wetland, denoted as NBCW, includes an artificial wetland pool 1, a water inlet pipeline 6 and wetland plants 11. The filler layers of the artificial wetland pool 1 include a soft fine sand layer 2, a quartz sand layer 3, a zeolite and modified biochar mixed layer 4 and a gravel layer 5 from top to bottom. The wetland plant 11 planted in the quartz sand layer 3 is Siberian iris. The planting density of Siberian iris is 4 plants / m 2 The height of the soft fine sand layer 2 is 1 cm, the height of the quartz sand layer 3 is 9 cm, the height of the zeolite and modified biochar mixed layer 4 is 40 cm, and the height of the gravel layer 5 is 5 cm. The particle size of the quartz sand is 3-5 cm. The particle size of the zeolite is ≤2 mm. The artificial wetland pool 1 is made of organic glass and is cylindrical in shape with a diameter of 21 cm and a height of 65 cm.

[0056] The zeolite and modified biochar mixed layer 4 is obtained by mixing modified biochar and zeolite, the volume of the modified biochar is 25% of the volume of the zeolite, and the modified biochar is sodium hydroxide modified biochar; the preparation method of the modified biochar comprises the following steps: cutting corn stalks into 5-10 cm lengths, pyrolyzing under nitrogen conditions, and heating at a rate of 10°C·min -1The pyrolysis temperature was 450±25℃, the pyrolysis time was 2.0h, the pyrolysis product was soaked and rinsed, the ash on the surface was removed, and the product was dried at 65℃ to constant weight to obtain biochar. The biochar and the concentration of 0.1mol∙L -1 The modified product was mixed evenly with sodium hydroxide solution for 24 hours, washed until neutral, and dried at 100°C for later use.

[0057] The water inlet pipe 6 passes through the packing layer of the artificial wetland pool 1, and the water outlet of the water inlet pipe 6 is located in the quartz sand layer 3. A liquid valve 7 and a liquid flow meter 8 are installed in sequence on the water inlet pipe 6 outside the artificial wetland pool 1. A water outlet pipe 10 is provided on one side of the bottom of the side wall of the artificial wetland pool 1, and a sampling tube 9 is provided on the other side.

[0058] The inlet and outlet pipes were opened to start the operation of the artificial wetland. The water containing sulfonamide antibiotics and resistance genes entered the artificial wetland through the inlet pipe. The hydraulic retention time was 7 days, the effective volume of the artificial wetland was 7L, and the hydraulic load was 0.0531 m 3 / m 2 The whole operation cycle is carried out at a temperature of 22±4℃.

[0059] The concentration of sulfonamide antibiotics in water, the absolute abundance of antibiotic resistance genes and the influent load were tested three times. The test results of each indicator in the three tests ranged from:

[0060] The concentrations of sulfonamide antibiotics in water bodies are: sulfadiazine 5.80-5.83μg / L, sulfapyridine 5.50-5.51μg / L, sulfamethoxazole 6.66-6.68μg / L, sulfamethoxazole 5.39-5.40μg / L, sulfadimethoxine 5.26-5.27μg / L, sulfamethoxazole 6.28-6.29μg / L, sulfamethoxazole 4.54-4.55μg / L, sulfamethoxazole 6.29-6.30μg / L;

[0061] The absolute abundance of antibiotic resistance genes in water bodies is:

[0062] 16s rRNA 9.74×10 4 -2.48×10 5 copies / mL, intI1 2.37×10 4 -4.15×10 4 copies / mL,sul1 2.61×10 4 -4.55×10 4 copies / mL,sul2 1.48×10 4 -2.53×10 4 copies / mL;

[0063] Influent load: NH 4 + -N: 9.47-11.47 mg∙L -1 , NO 2 - -N: 0.04-0.72mg∙L -1 , NO 3 - -N: 2.93-5.69mg∙L -1 , TN: 15.13-17.17 mg∙L -1 , TP: 0.26-0.32mg∙L -1 , COD: 30.33-34.67mg∙L -1 .

[0064] The average values ​​of the three test results for each indicator are:

[0065] The concentration of sulfonamide antibiotics in water is:

[0066] The inlet concentrations of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were 5.82 μg / L, 5.50 μg / L, 6.67 μg / L, 5.40 μg / L, 5.26 μg / L, 6.28 μg / L, 4.54 μg / L, and 6.29 μg / L, respectively;

[0067] The absolute abundance of antibiotic resistance genes in water bodies is:

[0068] 16s rRNA 1.96×10 5 copies / mL, intI1 3.12×10 4 copies / mL, sul1 3.50×10 4 copies / mL and sul2 1.92×10 4 copies / mL;

[0069] Influent load: NH 4 + -N: 10.39 mg∙L -1 , NO 2 - -N: 0.22 mg∙L -1 , NO 3 - -N: 3.94 mg∙L -1 , TN: 15.83mg∙L -1 , TP: 0.30 mg∙L -1 , COD: 32.29mg∙L -1 .

[0070] Comparative Example 2

[0071] The artificial wetland, denoted as BCW, includes an artificial wetland pool 1 and a water inlet pipe 6. The filler layers of the artificial wetland pool 1 include a soft fine sand layer 2, a quartz sand layer 3, a zeolite and unmodified biochar mixed layer 4, and a gravel layer 5 from top to bottom; the height of the soft fine sand layer 2 is 1 cm, the height of the quartz sand layer 3 is 9 cm, the height of the zeolite and modified biochar mixed layer 4 is 40 cm, and the height of the gravel layer 5 is 5 cm. The particle size of the quartz sand is 3-5 cm. The particle size of the zeolite is ≤2 mm. The material of the artificial wetland pool 1 is plexiglass, and the shape is cylindrical, with a diameter of 21 cm and a height of 65 cm.

[0072] The zeolite and unmodified biochar mixed layer 4 is obtained by mixing biochar and zeolite, and the volume of biochar is 25% of the total volume. The method for making biochar includes the following steps: cutting corn stalks into 5-10 cm lengths, pyrolyzing under nitrogen conditions, and heating at a rate of 10 °C·min -1 The pyrolysis temperature was 450 ± 25 °C, the pyrolysis time was 2.0 h, the pyrolysis product was soaked and rinsed, the ash on the surface was removed, and the biochar was obtained by drying at 65 °C to constant weight.

[0073] The water inlet pipe 6 passes through the packing layer of the artificial wetland pool 1, and the water outlet of the water inlet pipe 6 is located in the quartz sand layer 3. A liquid valve 7 and a liquid flow meter 8 are installed in sequence on the water inlet pipe 6 outside the artificial wetland pool 1. A water outlet pipe 10 is provided on one side of the bottom of the side wall of the artificial wetland pool 1, and a sampling tube 9 is provided on the other side.

[0074] The inlet and outlet pipes were opened to start the operation of the artificial wetland. The water containing sulfonamide antibiotics and resistance genes entered the artificial wetland through the inlet pipe. The hydraulic retention time was 7 days, the effective volume of the artificial wetland was 7L, and the hydraulic load was 0.0531 m 3 / m 2 The whole operation cycle is carried out at a temperature of 22±4℃.

[0075] The concentration of sulfonamide antibiotics in water, the absolute abundance of antibiotic resistance genes and the influent load were tested three times. The test results of each indicator in the three tests ranged from:

[0076] The concentrations of sulfonamide antibiotics in the water body were: sulfadiazine 5.80 - 5.83 μg / L, sulfapyridine 5.50 - 5.51 μg / L, sulfamethoxazole 6.66 - 6.68 μg / L, sulfamerazine 5.39 - 5.40 μg / L, sulfamethazine 5.26 - 5.27 μg / L, sulfamonomethoxine 6.28 - 6.29 μg / L, sulfamethoxydiazine 4.54 - 4.55 μg / L, sulfamethoxypyridazine 6.29 - 6.30 μg / L;

[0077] The absolute abundances of antibiotic resistance genes in the water body were:

[0078] 16s rRNA 9.74×10 4 -2.48×10 5 copies / mL, intI1 2.37×10 4 -4.15×10 4 copies / mL, sul1 2.61×10 4 -4.55×10 4 copies / mL, sul2 1.48×10 4 -2.53×10 4 copies / mL;

[0079] The influent load was: NH 4 + -N: 9.47 - 11.47 mg∙L -1 NO 2 - -N: 0.04 - 0.72 mg∙L -1 NO 3 - -N: 2.93 - 5.69 mg∙L -1 TN: 15.13 - 17.17 mg∙L -1 TP: 0.26 - 0.32 mg∙L -1 COD: 30.33 - 34.67 mg∙L -1 .

[0080] The average values of the three detection results of each index were:

[0081] The concentrations of sulfonamide antibiotics in the water body were:

[0082] The influent concentrations of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were 5.82 μg / L, 5.50 μg / L, 6.67 μg / L, 5.40 μg / L, 5.26 μg / L, 6.28 μg / L, 4.54 μg / L, and 6.29 μg / L, respectively;

[0083] The absolute abundance of antibiotic resistance genes in water bodies is:

[0084] 16s rRNA 1.96×10 5 copies / mL, intI1 3.12×10 4 copies / mL, sul1 3.50×10 4 copies / mL and sul2 1.92×10 4 copies / mL;

[0085] Influent load: NH 4 + -N: 10.39 mg∙L -1 , NO 2 - -N: 0.22 mg∙L -1 , NO 3 - -N: 3.94 mg∙L -1 , TN: 15.83mg∙L -1 , TP: 0.30 mg∙L -1 , COD: 32.29mg∙L -1 .

[0086] Comparative experiment of comparative example 1 and comparative example 2

[0087] 1. Advantages of alkaline-modified biochar matrix constructed wetlands in removing ARGs (antibiotic resistance genes)

[0088] Based on the recorded water sample volumes, the absolute abundance of ARGs was obtained, and all target ARGs were detected in both the inlet and effluent. The absolute abundance of 16S rRNA, intI1, and sul in the inlet and effluent of the modified biochar constructed wetland and unmodified biochar constructed wetland systems is shown in Figure 2. Figure 1 As shown in Figure a and Figure b. Figure 1 Figures c and d show the removal rates of individual target genes and the total removal rate of the system. The absolute abundances of 16S rRNA, intI1, sul1, and sul2 in the influent of the BCW and NBCW systems were 1.96×10 5 copies / mL, 3.12×10 4 copies / mL, 3.50×10 4 copies / mL and 1.92×10 4 copies / mL, it can be seen that the absolute abundance of 16S rRNA in the influent is the highest indicator. In addition, the absolute abundance of sul1 in the influent is relatively high, which is the most common sulfonamide antibiotic resistance gene, and the absolute abundance of sul2 is the lowest.

[0089] Table 1 Relative abundances of target ARGs in the influent and effluent of constructed wetlands

[0090]

[0091] The relative abundance of a gene is the ratio of the absolute abundance of the target gene to the absolute abundance of 16S rRNA. Table 1 shows the relative abundances of target genes in the influent and effluent of constructed wetlands. The relative abundances of intI1, sul1, and sul2 in the influent were 2.13×10 -1 , 2.37×10 -1 , and 1.31×10 -1 , respectively. As can be seen from the table, after treatment by CWs, the relative abundances of intI1, sul1, and sul2 all decreased. The relative abundance of intI1 in the effluent was between 6.12×10 -2 and 7.97×10 -2 . The relative abundance of NBCW was higher than that of BCW. The relative abundance of sul1 was between 1.19×10 -1 and 7.90×10 -2 . The relative abundance of sul2 was between 9.56×10 -2 and 7.10×10 -2 . The relative abundances of sul1 and sul2 in the effluent of NBCW were lower than those of BCW, while the relative abundance of intI1 was higher than that of BCW.

[0092] Figure 1 In, the absolute abundances of 16S rRNA, intI1, and ARGs in the effluent of CWs all decreased significantly. After treatment by CWs, the absolute abundance of 16S rRNA in the effluent decreased. The absolute abundances of BCW and NBCW were 1.81×10 5 copies / mL and 1.54×10 5 copies / mL, respectively. The absolute abundance of NBCW in the effluent was lower than that of BCW, indicating that NBCW could better adjust the 16S rRNA in the effluent. The absolute abundances of intI1, sul1, and sul2 in the effluent of BCW were 1.07×10 4 copies / mL, 2.06×10 4 copies / mL, and 1.65×10 4 copies / mL, respectively. The absolute abundances in the effluent of NBCW were 1.09×10 4 copies / mL, 1.08×10 4 copies / mL, and 9.79×10 3copies / mL. After the CWs treatment, the abundances of the target ARGs all decreased. In Figure 1 Figure c of Figure 1 , the removal log values of intI1, sul1, and sul2 in BCW were 0.45, 0.22, and 0.06 respectively, and the total removal log value was 0.24. In NBCW, the removal log values were 0.44, 0.50, and 0.28 respectively, and the total removal log value was 0.42. In BCW, intI1 was removed the most, and sul2 had the worst removal effect. In NBCW, sul1 had the best removal effect. Compared with the effluent of BCW, the absolute abundance removal rates of sul1 and sul2 in NBCW both increased, especially sul1, while the removal rate of intI1 decreased slightly. It shows that the modified biochar has a better ability to remove sul, while the unmodified biochar matrix constructed wetland has a more obvious removal effect on intI1. Generally speaking, the overall removal effect of the target genes is: NBCW > BCW.

[0093] The matrix is a very important part in CWs and is the main place where various biological reactions in CWs occur. It can not only remove pollutants through its own adsorption ability, but also provide a living place for microorganisms by fixing plant roots, and cooperate with the removal of pollutants. CWs plants adsorb pollutants in the system through their rich root systems, and the adsorbed pollutants are transferred to various tissues by the plant through plant metabolic processes such as transpiration. Figure 2 Are the absolute abundances of 16S rRNA and ARGs in the matrix and plants. Figure 2 Figure a of Figure 2 shows the absolute abundances of 16S rRNA in the CWs matrix and plants. It can be seen that the absolute abundance of 16S rRNA in the plant roots is the highest, followed by the matrix, and the lowest in the plant stems and leaves, with absolute abundances of 6.23×10 7 - 6.83×10 8 copies / mL, 8.76×10 7 - 2.22×10 8 copies / mL, and 3.80×10 6 - 4.67×10 7 copies / mL. Among the four CW systems, the absolute abundance in NBCW is the highest, and the absolute abundance of 16S rRNA in the plant root tissue of NBCW is the highest, far higher than other tissues.

[0094] II. Adsorption of ARGs by the matrix and plant tissues

[0095] Figure 2 Figure b of Figure 2 shows the absolute abundances of the target genes in the CWs matrix. The biochar matrix shows excellent adsorption ability. The absolute abundances of intI1, sul1, and sul2 in the BCW matrix are 1.72×106 copies / g, 1.80×10 6 copies / g and 3.87×10 6 copies / g, and the absolute abundances of intI1, sul1, and sul2 in the NBCW matrix were 4.68×10 6 copies / g、7.11×10 6 copies / g and 5.61×10 6 Comparison of the adsorption of ARGs by the matrix of BCW and NBCW systems revealed that the absolute abundance of intI1, sul1 and sul2 adsorbed by NBCW was higher, especially the adsorption of sul1, which was much greater than that of BCW, which was consistent with the effluent level of CWs, indicating that the modified biochar had a greater potential for removing resistance genes.

[0096] After the experiment, all plant samples (roots, stems and leaves) collected were tested by qPCR. Figure 2 Figures a, c, and d are the abundances of 16S rRNA, intI1, and ARGs in wetland plant tissues. In plant tissues, the absolute abundances of intI1, sul1, and sul2 in plant roots were 4.51×10 6 and 5.25×10 7 copies / g、8.06×10 5 and 4.69×10 5 copies / g, 1.14×10 6 and 7.03×10 5 The absolute abundances of intI1, sul1 and sul2 in plant stems and leaves were 3.81×10 5 copies / g and 8.33×10 5 copies / g、9.27×10 3 copies / g and 9.96×10 3 copies / g, 1.12×10 4 copies / g and 1.23×10 4copies / g. The absolute abundance of ARGs in plant roots is much greater than that in plant stems and leaves, and its abundance is greater than 1-2 orders of magnitude. This shows that plants absorb ARGs through roots and transfer them to other tissues through material circulation and energy flow, but only a small part is transferred, and most of them are concentrated in root tissues. This shows that plant roots play an important role in ARGs removal. Plant roots are also the main attachment site for microorganisms. ARGs exist in root biofilms and suspended solids. Plant roots release oxygen and secrete chemicals to regulate the relationship between plants and microorganisms, affecting the absolute abundance of ARGs. The sources of ARGs in stems and leaves are through the following two pathways: (1) ARGs in the water environment will be transferred to the plant surface with aerosols in the air; (2) host bacteria in root tissues will be transferred to stem and leaf tissues through metabolic methods such as plant transpiration.

[0097] 3. Removal of SAs (sulfonamide antibiotics) by alkaline-modified biochar matrix constructed wetlands

[0098] Figure 3 Figure a shows the effluent concentration after the artificial wetland removes sulfonamide antibiotics; Figure b shows the removal rate. According to the LC / MS-MS test results, the influent concentrations of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ during the operation period were 5.82μg / L, 5.50μg / L, 6.67μg / L, 5.40μg / L, 5.26μg / L, 6.28μg / L, 4.54μg / L, and 6.29μg / L, respectively. The effluent concentrations in BCW and NBCW were 0.351 μg / L and 0.294 μg / L, 0.240 μg / L and 0.248 μg / L, 0.019 μg / L and 0.024 μg / L, 0.256 μg / L and 0.216 μg / L, 0.363 μg / L and 0.322 μg / L, 0.245 μg / L and 0.208 μg / L, 0.214 μg / L and 0.146 μg / L, 0.230 μg / L and 0.173 μg / L, respectively. It can be seen that the ecological risk of sulfonamide antibiotics was greatly reduced after CW treatment. BCW and NBCW had significant and stable removal effects on the eight SAs, and the removal rates of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were maintained at 93.97% and 94.95%, 95.63% and 95.49%, 99.71% and 99.64%, 95.26% and 96.00%, 93.10% and 93.89%, 96.09% and 96.70%, 95.29% and 96.79%, and 96.34% and 97.257%. Comparing the treatment effects of different groups, the overall SAs removal efficiency of the three groups of NBCW was in the following order: NBCW>BCW.

[0099] Screening test of water load for artificial wetlands:

[0100] 1. Advantages of NBCW1, NBCW2 and NBCW3 alkaline-modified biochar matrix constructed wetlands in removing ARGs

[0101] Table 2 Influent load of constructed wetlands with different modified biochar composite matrices

[0102]

[0103] NBCW1 (equivalent to NBCW in the artificial wetland of Comparative Example 1) and NBCW3 are the same as NBCW2 in the artificial wetland of Example 1, the concentration of sulfonamide antibiotics in the water body and the absolute abundance of antibiotic resistance genes in the water body are the same, and only the influent load is different.

[0104] In NBCW3, the concentration of sulfonamide antibiotics in water, the absolute abundance of antibiotic resistance genes and the influent load were tested three times. The range of the test results of each indicator in the three tests was:

[0105] The concentrations of sulfonamide antibiotics in water bodies are: sulfadiazine 5.80-5.83μg / L, sulfapyridine 5.50-5.51μg / L, sulfamethoxazole 6.66-6.68μg / L, sulfamethoxazole 5.39-5.40μg / L, sulfadimethoxine 5.26-5.27μg / L, sulfamethoxazole 6.28-6.29μg / L, sulfamethoxazole 4.54-4.55μg / L, sulfamethoxazole 6.29-6.30μg / L;

[0106] The absolute abundance of antibiotic resistance genes in water bodies is:

[0107] 16s rRNA 9.74×10 4 -2.48×10 5 copies / mL, intI1 2.37×10 4 -4.15×10 4 copies / mL,sul1 2.61×10 4 -4.55×10 4 copies / mL,sul2 1.48×10 4 -2.53×10 4 copies / mL;

[0108] Influent load: NH 4 + -N: 27.70-33.47mg∙L -1 , NO 2 - -N: 0.04-0.73mg∙L-1 , NO 3 - -N: 3.23-5.68mg∙L -1 , TN: 34.50-39.03mg∙L -1 , TP: 1.40-1.51 mg∙L -1 , COD: 117.33-129.33mg∙L -1 .

[0109] The average values ​​of the three test results for each indicator are:

[0110] The concentration of sulfonamide antibiotics in water is:

[0111] The inlet concentrations of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were 5.82 μg / L, 5.50 μg / L, 6.67 μg / L, 5.40 μg / L, 5.26 μg / L, 6.28 μg / L, 4.54 μg / L, and 6.29 μg / L, respectively;

[0112] The absolute abundance of antibiotic resistance genes in water bodies is:

[0113] 16s rRNA 1.96×10 5 copies / mL, intI1 3.12×10 4 copies / mL, sul1 3.50×10 4 copies / mL and sul2 1.92×10 4 copies / mL;

[0114] Influent load: NH 4 + -N: 31.12 mg∙L -1 , NO 2 - -N: 0.23 mg∙L -1 , NO 3 - -N: 3.93 mg∙L -1 , TN: 36.54mg∙L -1 , TP: 1.46mg∙L -1 , COD: 123.04mg∙L -1 .

[0115] The inlet and outlet pipes were opened to start the operation of the artificial wetland. The water containing sulfonamide antibiotics and resistance genes entered the artificial wetland through the inlet pipe. The hydraulic retention time was 7 days, the effective volume of the artificial wetland was 7L, and the hydraulic load was 0.0531 m 3 / m 2 ·h, the entire operating cycle was carried out at a temperature of 22 ± 4 °C. According to the recorded water sample volume, the absolute abundances of ARGs were obtained, and all target ARGs were detected in the influent and effluent. The absolute abundances of 16S rRNA, intI1, and ARGs in the influent and effluent of the modified biochar matrix constructed wetland system are shown in Figure 4 Figures a and b of Figure 4 Figures c and d of 5 are the removal rates of individual target genes and the total system removal rate. The absolute abundances of 16S rRNA, intI1, sul1, and sul2 in the influent of the three groups of systems were 1.96×10 4 copies / mL, 3.12×10 4 copies / mL, 3.50×10 4 copies / mL, and 1.92×10

[0116] Table 3 Relative abundances of target ARGs in the influent and effluent of the constructed wetland

[0117] The relative abundance of the gene is the ratio of the absolute abundance of the target gene to the absolute abundance of 16S rRNA. Table 3 shows the relative abundances of the target genes in the influent and effluent of CWs. The relative abundances of intI1, sul1, and sul2 in the influent were 2.13×10 -1 , 2.37×10 -1 , and 1.31×10 -1 , respectively. It can be seen from the table that after treatment by NBCWs, the relative abundances of intI1, sul1, and sul2 all decreased. The relative abundance of intI1 in the effluent was between 1.21×10 -2 - 7.97×10 -2 , with the highest relative abundance in NBCW1 and the lowest in NBCW3; the relative abundance of sul1 was between 1.29×10 -1 - 7.90×10 -2 , with the highest relative abundance in NBCW1 and the lowest in NBCW3; the relative abundance of sul2 was between 1.38×10 -2 - 7.10×10 -2 , with the highest relative abundance in NBCW1 and the lowest in NBCW2. It can be seen that as the influent load increases, the relative abundances of intI1 and sul1 decrease, while the relative abundance of sul2 first increases and then decreases

[0118] Increasing the organic load in the influent will increase the absolute abundance of 16S rRNA in the effluent of the modified biochar matrix constructed wetland system. The absolute abundance of 16S rRNA in the effluent is between 4.21×10 5 - 1.02×10 6 The absolute abundances of intI1, sul1, and sul2 in the effluent of NBCW2 were 1.84×104 copies / mL, 1.05×10 4 copies / mL and 7.15×10 3 copies / mL. The absolute abundances of NBCW3 effluent were 1.12×10 4 copies / mL, 1.20×10 4 copies / mL and 1.72×10 4 copies / mL. The removal log values ​​of intI1, sul1 and sul2 in NBCW2 were 0.23, 0.52 and 0.43, respectively, and in NBCW2 were 0.44, 0.46 and 0.04, respectively. With the increase of influent organic load, the absolute abundance of intI1 showed a trend of first increasing and then decreasing, while sul1 and sul2 showed a trend of first decreasing and then increasing, indicating the effect of organic load on sul removal. For sul1 and sul2, the effluent absolute abundance of NBCW2 was the lowest and the removal effect was the best. Sul2 showed the highest absolute abundance in NBCW3, indicating that with the increase of organic load, the relative abundance of sul2 host may increase, and the absolute abundance of sul2 will change accordingly. For intI1, the absolute abundance in BCW was the lowest and the absolute abundance in NBCW2 was the highest. Figure 4 Figure d shows the effect of each group of CW in removing total ARGs. The overall removal effect of ARGs is: NBCW1>NBCW2>NBCW3.

[0119] 2. Removal of ARGs by NBCW1, NBCW2, and NBCW3 matrices and plant tissues

[0120] Figure 5 Figure b shows the target genes in the CWs matrix. The modified biochar matrix showed excellent adsorption capacity. Changing the influent load affected the removal of ARGs by the modified biochar. The absolute abundances of intI1, sul1, and sul2 in the NBCW1 matrix were 4.68×10 6 copies / mL, 7.11×10 6 copies / mL and 5.61×10 6copies / mL, and the absolute abundances of intI1, sul1, and sul2 in the NBCW2 matrix were 5.95×10 6 copies / mL, 5.01×10 6 copies / mL and 3.72×10 6 copies / mL, and the absolute abundances of intI1, sul1, and sul2 in the NBCW3 matrix were 4.07×10 6 copies / mL, 5.86×10 6 copies / mL and 5.77×10 6 copies / mL. As the organic load of the artificial wetland influent increased, the absolute abundance of the total ARGs adsorbed by the NBCW matrix decreased. Among them, the absolute abundance of intI1 increased first and then decreased, while the absolute abundance of the sul gene decreased first and then increased. This is because the organic load affects the abundance of the ARGs host and N, P, etc. in the organic load will also occupy the modified biochar adsorption sites, causing the absolute abundance of the matrix adsorbed ARGs to decrease.

[0121] After the experiment, all plant samples (roots, stems, and leaves) collected were tested by qPCR. Figure 5 Figures a, c, and d show the abundance of 16S rRNA, intI1, and ARGs in wetland plant tissues. In plant tissues, the absolute abundances of intI1, sul1, and sul2 in plant roots were 1.51×10 6 - 3.64×10 7 copies / mL, 4.69×10 5 - 2.14×10 6 copies / mL and 7.03×10 5 - 4.53×10 6 copies / mL; the absolute abundances of intI1, sul1, and sul2 in plant stems and leaves were 1.22×10 5 - 8.33×10 5 copies / mL, 9.96×10 3 - 6.09×10 4 copies / mL and 1.23×10 4 - 1.42×10 5copies / mL. The absolute abundance of ARGs in plant roots is much greater than that in plant stems and leaves, and its abundance is greater than 1-2 orders of magnitude. This shows that plants absorb ARGs through roots and transfer them to other tissues through material circulation and energy flow, but only a small part is transferred, and most of them are concentrated in root tissues. This shows that plant roots play an important role in ARGs removal. Plant roots are also the main attachment site for microorganisms. ARGs exist in root biofilms and suspended solids. Plant roots release oxygen and secrete chemicals to regulate the relationship between plants and microorganisms, affecting the absolute abundance of ARGs. The sources of ARGs in stems and leaves are through the following two pathways: (1) ARGs in the water environment will be transferred to the plant surface with aerosols in the air; (2) host bacteria in root tissues will be transferred to stem and leaf tissues through metabolic methods such as plant transpiration. From the perspective of gene type, intI1 is the most abundant, consistent with other samples. However, the abundance of sul1 in plant tissues is less than that of sul2. According to different CWs, NBCW3 has the highest abundance, followed by NBCW2.

[0122] 3. Advantages of influent loads of NBCW1, NBCW2 and NBCW3 for SAs removal

[0123] according to Figure 6 Figure a shows the effluent concentration after the removal of sulfonamide antibiotics by artificial wetlands; Figure b shows the removal rate LC / MS-MS test results. During the operation, the influent concentrations of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were 5.82μg / L, 5.50μg / L, 6.67μg / L, 5.40μg / L, 5.26μg / L, 6.28μg / L, 4.54μg / L, and 6.29μg / L, respectively, while the effluent concentrations were 0.28~0.32 μg / L, 0.14~0.28 μg / L, 0.17~0.22 μg / L, 0.02~0.06 μg / L, 0.16~0.32 μg / L, 0.21~0.24 μg / L, 0.15~0.16 μg / L, 0.15~0.22 μg / L. It can be seen that after CW treatment, the ecological risk of sulfonamide antibiotics was greatly reduced. CW had a significant and stable removal effect on the eight SAs, and the removal rates of SD, SPD, SMX, SMD, SM2, SMT, SM, and SPZ were maintained at 94.52-95.21%, 94.89-97.49%, 99.08-99.64%, 96.00-96.91%, 93.89-97.03%, 96.20-96.70%, 96.49-96.79%, and 96.55-97.57%. Comparing the treatment effects of different groups, the overall SAs removal efficiency of the three groups of NBCW is in the following order: NBCW2>NBCW3>NBCW1.

[0124] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An application of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water, characterized in that: The artificial wetland comprises an artificial wetland pool, a water inlet pipeline and wetland plants. The filler layers of the artificial wetland pool comprise, from top to bottom, a soft fine sand layer, a quartz sand layer, a zeolite and modified biochar mixed layer and a gravel layer. The wetland plant planted in the quartz sand layer is Siberian iris. The zeolite and modified biochar mixed layer is obtained by mixing modified biochar and zeolite, the volume of the modified biochar is 25% of the volume of the zeolite, and the modified biochar is sodium hydroxide modified biochar; The water inlet pipeline passes through the packing layer of the artificial wetland pool, the water outlet of the water inlet pipeline is located in the quartz sand layer, a liquid valve and a liquid flow meter are sequentially installed on the water inlet pipeline outside the artificial wetland pool, and a water outlet pipe is provided on one side of the bottom of the side wall of the artificial wetland pool, and a sampling tube is provided on the other side; The application includes the following steps: The water inlet pipe and the water outlet pipe are opened to start the operation of the artificial wetland, and the water containing sulfonamide antibiotics and resistance genes enters the artificial wetland through the water inlet pipe. The hydraulic retention time is 7 days, and the temperature of the entire operation cycle is carried out at 22±4°C; The concentrations of sulfonamide antibiotics in water bodies are: sulfadiazine 5.80-5.83μg / L, sulfapyridine 5.50-5.51μg / L, sulfamethoxazole 6.66-6.68μg / L, sulfamethoxazole 5.39-5.40μg / L, sulfadimethoxine 5.26-5.27μg / L, sulfamethoxazole 6.28-6.29μg / L, sulfamethoxazole 4.54-4.55μg / L, sulfamethoxazole 6.29-6.30μg / L; The absolute abundance of antibiotic resistance genes in water bodies is: 16s rRNA 9.74×10 4 -2.48×10 5 copies / mL,intI1 2.37×10 4 -4.15×10 4 copies / mL,sul1 2.61×10 4 -4.55×10 4 copies / mL,sul2 1.48×10 4 -2.53×10 4 copies / mL; Influent load: NH4 + -N: 19.43-21.83mg∙L -1 , NO2 - -N: 0.04-0.37mg∙L -1 , NO3 - -N: 2.20-5.80mg∙L -1 , TN: 23.57-27.93 mg∙L -1 , TP: 0.99-1.1mg∙L -1 , COD: 73.67-80mg∙L -1 .

2. The use of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water according to claim 1, characterized in that: The height of the soft fine sand layer is 1 cm, the height of the quartz sand layer is 10 cm, the height of the zeolite and modified biochar mixed layer is 40 cm, and the height of the gravel layer is 5 cm.

3. The use of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water according to claim 1, characterized in that: The particle size of the quartz sand is 3-5 cm.

4. The use of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water according to claim 1, characterized in that: The method for preparing the modified biochar comprises the following steps: Corn stalks were chopped and pyrolyzed under nitrogen. The pyrolysis products were soaked and rinsed to remove the ash on the surface and dried to constant weight to obtain biochar. The biochar was mixed with a concentration of 0.1 mol∙L -1 The mixture is mixed evenly with sodium hydroxide solution for modification, washed to neutrality, and dried for later use.

5. The use of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water according to claim 1, characterized in that: The particle size of the zeolite is ≤2 mm.

6. The use of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water according to claim 1, characterized in that: The planting density of the Siberian iris is 4 plants / m 2 .

7. The use of an artificial wetland in removing sulfonamide antibiotics and resistance genes in water according to claim 1, characterized in that: The artificial wetland pool is made of plexiglass and is cylindrical in shape with a diameter of 21 cm and a height of 65 cm.

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