Preparation method and application of cerium-doped goethite adsorption material

Abstract

The invention discloses a preparation method and application of a cerium-doped goethite adsorption material. The cerium doped goethite adsorption material Ce-FeOOH is formed by doping metal cerium Ce with goethite FeOOH; the doping amount of Ce is 1.5-10.9 wt%, Ce is loaded on the surface of FeOOH in a mixed valence state form of Ce (III) and Ce (IV), and the proportion of Ce (III) is 17.8-30.0%. The Ce-FeOOH adsorption material keeps excellent adsorption stability in the water body polluted by the extracellular antibiotic resistance gene eARGs with wide pH range and high ionic strength. The problems of limited adsorption capacity, pH sensitivity and the like of a traditional material are solved by adopting a controllable doping method, high efficiency and economical efficiency are achieved in eARGs pollution control of a complex salinity water environment, and an innovative solution is provided for eARGs pollution control of a water body.

Description

Technical Field

[0001] The present invention relates to the technical field of environmental functional materials, and particularly to a preparation method and application of a cerium-doped goethite adsorption material. The adsorption material realizes the efficient capture and removal of extracellular antibiotic resistance genes under complex water environment conditions through controllable doping and surface modification technologies, and is applicable to the treatment of complex water environments. Background Art

[0002] In recent years, the spread of antibiotic resistance genes (ARGs) in water bodies has become a major challenge in the global public health field. The 2021 report of the World Health Organization (WHO) pointed out that the number of deaths caused by drug-resistant bacterial infections exceeds 1.27 million every year, and is expected to climb to 10 million by 2050. Among them, extracellular antibiotic resistance genes (eARGs) exist widely in the water environment in the form of plasmids, free DNA fragments, etc. Their environmental persistence (half-life can reach several weeks to several months) and horizontal transfer potential are significantly higher than those of intracellular ARGs. eARGs can enter the human body through drinking water, irrigation water and other channels, inducing pathogenic bacteria to acquire drug resistance and seriously threatening the safety of the medical system. Currently, the removal technologies for eARGs in water bodies mainly include advanced oxidation processes, biodegradation methods, and adsorption methods. The technical bottlenecks are as follows: Advanced oxidation processes such as ultraviolet (UV), persulfate (PS), and Fenton can destroy the DNA strand structure through free radical attacks, but they have significant defects, such as the risk of by-products. Hydroxyl radicals (·OH) attack organic substances indiscriminately and may degrade large molecular eARGs into smaller fragments (<500bp) that are more easily taken up by bacteria, which instead promotes the spread of resistance. Additionally, this method is costly, consumes a large amount of electrical energy when treating water bodies, and requires continuous addition of chemical reagents (such as H2O2), resulting in rising operating costs. Biodegradation methods such as biofilm technology functionalized with phages and nucleases have the advantage of specific recognition, but functional enzymes have poor tolerance in complex environments, and the environmental release of genetically engineered bacteria may also trigger ecological safety disputes. In contrast, the adsorption method does not require other energy or reaction reagents, is simple and green, and has great development potential. However, traditional adsorption materials also have limitations. For example, activated carbon has low efficiency and poor selectivity; although nano-zero-valent iron (nZVI) has the ability to reduce and degrade, it is easily oxidized and inactivated under aerobic conditions and will cause DNA strand breakage to produce shorter fragments that are more easily transferred; eARGs carry a strong negative charge (Zeta potential ≈ -30mV) in natural water bodies (pH 7.0 - 8.0), while the isoelectric points (pHpzc) of traditional metal oxide adsorbents (such as Al2O3, Fe3O4) are mostly higher than 8.0, resulting in electrostatic repulsion; although commercial anion exchange resins can capture DNA through electrostatic attraction, they are significantly affected by the competitive adsorption of humic acid. Therefore, it is very necessary to seek more effective and reliable adsorbents to achieve the efficient removal of free eARGs. Goethite (FeOOH) is regarded as a potential adsorbent due to its environmental friendliness and rich surface hydroxyl groups, but its inherent properties severely limit its adsorption efficiency for eARGs, such as surface charge mismatch, pore size mismatch, and environmental sensitivity. Based on the above defects, the present invention selects cerium (Ce) as the doping element, and its unique physical and chemical properties break through the limitations of traditional adsorption materials through the following mechanisms: (1) Enrichment of active sites and coordination bonding. After Ce element doping, the surface hydroxyl density can be increased, or oxygen vacancy active sites can be introduced. The Ce-OH group (pKa ≈ 6.8) is preferentially protonated at physiological pH and becomes a strong coordination site for the DNA phosphate group (pKa ≈ 1.5). The Ce-O-Fe bond forms an electron transfer channel, enhancing the π-π stacking interaction with DNA bases and improving adsorption. The formation of oxygen vacancies and the exposure of surrounding unpaired Ce(III) / Fe(III) can also provide more adsorption sites for eARGs. (2) Optimization of surface charge and enhancement of electrostatic attraction. Ce 3+ substitutes Fe in the FeOOH lattice 3+ and then enhances the protonation trend. The isoelectric point of the doped material decreases, increasing the electrostatic attraction ability with negatively charged eARGs. Based on the above theoretical basis, the cerium-doped goethite adsorbent Ce-FeOOH is expected to achieve efficient, stable, and sustainable adsorption and removal of eARGs through multiple synergistic mechanisms of strengthened coordination bonding, optimized surface charge, and enhanced anti-interference ability. Summary of the Invention

[0003] Technical problems to be solved: In view of the problems of low removal efficiency of extracellular antibiotic resistance genes in water bodies and poor environmental adaptability of existing adsorbents, the present invention provides a cerium-doped goethite adsorbent (Ce-FeOOH) and its preparation method, which are applied to the remediation of water bodies contaminated with extracellular antibiotic resistance genes.

[0004] Technical solution: A cerium-doped goethite adsorbent and its preparation method. The cerium-doped goethite adsorbent Ce-FeOOH is composed of metal cerium Ce doped into goethite FeOOH; Ce is loaded on the surface of FeOOH in the form of a mixed valence state of Ce(III) and Ce(IV), and the proportion of Ce(III) is 17.8 - 30.0%. The preparation method of the cerium-doped goethite adsorbent includes the following steps: S1. Pretreatment of the precursor: Place FeOOH particles in a low-concentration acid solution, oscillate and react, then wash until neutral, and vacuum dry to obtain pretreated FeOOH. S2. Ce ion loading and purification: Dissolve a cerium salt in water to obtain a cerium salt solution, mix the cerium salt solution and FeOOH, ultrasonically disperse and then oscillate and react to form a composite solution, and finally dialyze the composite solution and vacuum dry to obtain the Ce-FeOOH adsorbent. Preferably, the low-concentration acid solution in step S1 is one or more of nitric acid, hydrochloric acid, and sulfuric acid solutions. Preferably, the oscillation reaction time in step S1 is 20 - 40 min, and the vacuum drying temperature is 40 - 60 °C. Preferably, the cerium salt solution in step S2 is any one or more of cerium chloride, cerium nitrate, cerium sulfate, and their hydrates. Preferably, the Ce doping amount of the Ce-FeOOH adsorbent in step S2 is 1.5 - 10.9 wt%. Furthermore, the Ce doping amount of the Ce-FeOOH adsorbent in step S2 is 10.9 wt%. Preferably, the ultrasonic reaction frequency in step S2 is 30 - 50 kHz; the time is 20 - 40 min; the oscillation reaction temperature is 23 - 26 °C, the rotation speed is 170 - 190 rpm, and the time is 22 - 26 h. Application of the Ce-FeOOH adsorbent in removing extracellular antibiotic resistance genes eARGs in water bodies. Method for applying the Ce-FeOOH adsorbent material to remove extracellular antibiotic resistance genes (eARGs) in water body, comprising the following steps: S1. Adjust the pH of the water body to be treated containing eARGs pollution to (4.0 - 8.0) ± 0.1, and use neutral salt to adjust the salt content of the water body to be treated ≥ 10 mmol / L; S2. Disperse the Ce-FeOOH adsorbent material in the water body to be treated, oscillate and mix at 23 - 26 °C and 170 - 190 rpm for 30 - 120 min, and centrifuge to separate the Ce-FeOOH-eARGs complex; S3. Immerse the complex in NaOH solution to achieve the disinfection of eARGs in the water body and the desorption and regeneration of the Ce-FeOOH material. Preferably, the pH of the water body to be treated in step S1 is (4.0 - 7.0) ± 0.1. Furthermore, the pH of the water body to be treated in step S1 is ≤ 7.0 ± 0.1. Preferably, the salt content of the water body to be treated in step S1 is 10 - 500 mmol / L. Furthermore, the salt content of the water body to be treated in step S1 is ≥ 10 mmol / L. Preferably, the dosage of the Ce-FeOOH adsorbent material in the water body to be treated in step S2 is 10 - 80 mg / L. Furthermore, the dosage of the Ce-FeOOH adsorbent material in the water body to be treated in step S2 is ≥ 80 mg / L. Preferably, the adsorption time for the Ce-FeOOH adsorbent material to remove eARGs pollution in the water body in step S2 is 0 - 360 min. Furthermore, the adsorption time for the Ce-FeOOH adsorbent material to remove eARGs pollution in the water body in step S2 is ≥ 60 min. Preferably, when the pH of the water body to be treated in step S2 is 7.0 ± 0.1, it is necessary to adjust the salt content of the water body to be treated ≥ 10 mmol / L and the dosage of the Ce-FeOOH adsorbent material ≥ 80 mg / L. Preferably, when the water body to be treated in step S2 is one or more of pH < 7.0 ± 0.1 or salt content > 10 mmol / L, select the Ce-FeOOH adsorbent material with a Ce doping amount of 10.9%, and adopt one or more methods such as an adsorbent material dosage of 50 - 80 mg / L or shortening the adsorption time to 30 - 60 min. Preferably, the concentration of the NaOH solution in step S3 is 0.05 - 0.2 mol / L, and the desorption and regeneration time is 30 - 360 min. Further, the concentration of the NaOH solution in step S3 is 0.2 mol / L, and the desorption and regeneration time is 30 min. Application of the above-mentioned Ce-FeOOH adsorbent material in the repair of extracellular antibiotic resistance gene-polluted water bodies. Beneficial effects Compared with traditional adsorbents, the present invention has the following beneficial effects: 1. Improved adsorption efficiency: Double optimization of fast kinetics and high adsorption capacity is achieved. It not only realizes strong chelation of the phosphate groups of eARGs, but also shortens the adsorption equilibrium time. 2. Improved environmental adaptability: The modified material can adapt to a wide pH tolerance range, breaking through the bottleneck of the pH limitation of traditional materials, and performing excellently in applications with various salinity ranges from fresh water to medium saline water to saline water. 3. Green sustainability: Using low-cost raw materials combined with a low-carbon preparation process significantly reduces the carbon emissions during material production. At the same time, by precisely controlling the process parameters to control the material structure, it provides an efficient, sustainable, and green solution for the treatment of eARGs pollution. Description of the drawings Figure 1 Adsorption effects of Ce-FeOOH adsorbent materials C0 - C5 with different Ce doping amounts on eARGs in water bodies; Figure 2 Adsorption effects of different dosages of Ce-FeOOH adsorbent material C5 on eARGs in water bodies; Figure 3 Adsorption effects of Langmuir and Freundlich adsorption models fitting FeOOH and Ce-FeOOH adsorbent material C5 on different concentrations of eARGs in water bodies; Figure 4 Adsorption effects of Ce-FeOOH adsorbent material C5 on eARGs in water bodies at different pH values; Figure 5 Adsorption effects of Ce-FeOOH adsorbent material C5 on eARGs in water bodies at different NaCl concentrations; Figure 6 Disinfection effects of different concentrations of NaOH on eARGs adsorbed by Ce-FeOOH adsorbent material C5; Figure 7 Recycling performance of Ce-FeOOH adsorbent material C5 after desorption and regeneration with NaOH; Figure 8Comparison of the adsorption effects of different metal-doped FeOOH and Ce-doped Fe3O4 on eARGs in water Detailed implementation mode To further understand the present invention, the preferred implementation modes of the present invention will be described below in conjunction with embodiments The specific preferred examples are as follows Example 1 This example is about the preparation method of Ce-doped 10.9wt% Ce-FeOOH adsorption material C5 and its adsorption effect on the extracellular resistance gene (Amp) pollution in water, including the following steps (1) Preparation of Ce-doped 10.9wt% Ce-FeOOH adsorption material C5 S1. Pretreatment of the precursor: Place FeOOH particles in a 0.1mol / L nitric acid solution and shake for 30min. Wash until neutral (pH = 7.0 ± 0.1), and vacuum dry at 50°C to obtain pretreated FeOOH S2. Ce ion loading and purification: Accurately weigh cerium chloride heptahydrate (CeCl3·7H2O, 99.9%) and dissolve it in 50mL of deionized water. Add the pretreated FeOOH, ultrasonically disperse it at 40kHz for 30min, and then react at 25°C and 180rpm for 24h to form a composite solution. Transfer the composite solution into a dialysis bag with a molecular weight cut-off of 5 - 10kDa, and place it in a 2L ultrapure water system for dialysis to remove unstable impurities. After centrifuging and collecting the precipitate, perform three-stage washing with ultrapure water (repeat the centrifugation-resuspension cycle 3 times), and vacuum dry at 50°C to obtain Ce-doped 10.9wt% Ce-FeOOH adsorption material C5 (2) Extract eARGs S1. Use Escherichia coli DH5α carrying the ampicillin resistance gene (Amp) plasmid as the template strain. Take 0.1mL of the engineered bacterial liquid frozen at -80°C, inoculate it into 500mL of LB liquid medium containing 100μg / mL Amp, and shake culture at 37°C and 180rpm for 16h until the logarithmic growth phase (OD 600 = 0.6 - 0.8); S2. Centrifuge the bacterial liquid at 4000×g for 10min at 4°C to collect the bacteria and extract and purify the plasmid. The extracted plasmid is detected for plasmid integrity through a real-time fluorescence quantitative PCR system (qPCR). After confirming the plasmid purity (A 260 / A 280 = 1.82 ± 0.05), aliquot and store it in a -80°C ultra-low temperature refrigerator (3) Adsorption experiment of Ce-FeOOH adsorption material C5 on the extracellular resistance gene (Amp) pollution in water S1. Establish a 0.4 mL reaction system in a 2.0 mL sterile and enzyme - free EP tube, containing 0.1 mg / L Amp and 50 mg / L C5 adsorbent; the pH of the reaction system is 7.0 ± 0.1, and the salt content is 10 mmol / L; S2. The reaction system is oscillated at 25 °C and 180 rpm. Samples are taken at preset time points (0 - 360 min). After centrifugation at 4 °C and 12000×g for 5 min, the supernatant is collected for qPCR detection, and the concentration of residual Amp resistance gene is calculated according to the standard curve. Example 2 This example is about the adsorption effect of Ce - FeOOH adsorbent C5 with a dosage of 80 mg / L on the extracellular resistance gene (Amp) pollution in water. The specific process is the same as that in Example 1. Example 3 This example is about the adsorption effect of Ce - FeOOH adsorbent C5 on the extracellular resistance gene (Amp) pollution in water when the concentration of extracellular resistance gene (Amp) in water is 0.025 mg / L, and it includes the following steps: S1. The preparation method of Ce - FeOOH adsorbent C5 is the same as that in Example 1; S2. Establish a 0.2 mL reaction system in a 2.0 mL sterile and enzyme - free EP tube, containing 0.025 mg / L Amp and 40 mg / L C5 adsorbent; the pH of the reaction system is 7.0 ± 0.1 and the salt content is 10 mmol / L; S3. The reaction system is oscillated at 25 °C and 180 rpm for 120 min. After centrifugation at 4 °C and 12000×g for 5 min, the supernatant is collected for qPCR detection, and the concentration of residual Amp resistance gene is calculated according to the standard curve; S4. The adsorption data is fitted by Langmuir and Freundlich adsorption models: The formula of the Langmuir adsorption model is: Q = (Q m bp) / (1 + bp), where: Q is the adsorption capacity (mmol / g), Q m is the saturated adsorption capacity (mmol / g), b is the adsorption equilibrium constant, and p is the partial pressure of the component (kPa); The formula of the Freundlich adsorption model is: Q = (Q m bp n ) / (1 + bp n ), where: n is the homogeneous index. Example 4 The difference between this example and Example 3 is the different concentration of extracellular resistance gene (Amp) in water. The concentration of Amp in this example is 0.05 mg / L. Example 5 The difference between this example and Example 3 lies in the different concentrations of extracellular resistance gene (Amp) in water. The concentration of Amp in this example is 0.075 mg / L. Example 6 The difference between this example and Example 3 lies in the different concentrations of extracellular resistance gene (Amp) in water. The concentration of Amp in this example is 0.1 mg / L. Example 7 The difference between this example and Example 3 lies in the different concentrations of extracellular resistance gene (Amp) in water. The concentration of Amp in this example is 0.15 mg / L. Example 8 The difference between this example and Example 3 lies in the different concentrations of extracellular resistance gene (Amp) in water. The concentration of Amp in this example is 0.2 mg / L. Example 9 The difference between this example and Example 3 lies in the different concentrations of extracellular resistance gene (Amp) in water. The concentration of Amp in this example is 0.4 mg / L. Example 10 This example shows the adsorption effect of Ce-FeOOH adsorbent C5 with a dosage of 50 mg / L on the pollution of extracellular resistance gene (Amp) in water when the pH of the water to be treated is 4.0 ± 0.1. The specific process is the same as that in Example 3. Example 11 The difference between this example and Example 10 lies in the different pH values of the water to be treated. The pH of the water to be treated in this example is 5.0 ± 0.1. Example 12 The difference between this example and Example 10 lies in the different pH values of the water to be treated. The pH of the water to be treated in this example is 6.0 ± 0.1. Example 13 The difference between this example and Example 10 lies in the different pH values of the water to be treated. The pH of the water to be treated in this example is 7.0 ± 0.1. Example 14 This example shows the adsorption effect of Ce-FeOOH adsorbent C5 with a dosage of 50 mg / L on the pollution of extracellular resistance gene (Amp) in water when the salt content of the water to be treated is 10 mmol / L. The specific process is the same as that in Example 3. Example 15 The difference between this example and Example 14 lies in the different salt contents of the water to be treated. The salt content of the water to be treated in this example is 100 mmol / L. Example 16 The difference between this example and Example 14 lies in the salt content of the water to be treated. The salt content of the water to be treated in this example is 500 mmol / L. Example 17 This example shows the effect of desorbing and regenerating the Ce-FeOOH adsorption material C5 with 0.05 mol / L NaOH solution for 360 min and simultaneously disinfecting eARG. The specific process is the same as that in Example 3. Example 18 The difference between this example and Example 17 is that the concentration of the NaOH solution in this example is 0.1 mol / L. Example 19 The difference between this example and Example 17 is that the concentration of the NaOH solution in this example is 0.2 mol / L. Example 20 This example shows the effect of the Ce-FeOOH adsorption material C5 on the adsorption of extracellular resistance gene (Amp) pollution in water. After regeneration of the adsorbent with 0.05 mol / L NaOH solution and simultaneous disinfection of eARG, the recycling effect of Ce-FeOOH is demonstrated. The specific process is the same as that in Example 3. To further illustrate the technical effects of the present invention, the present invention also sets up comparative examples as follows: Comparative Example 1 No adsorption material was added to the water body polluted by eARGs in this comparative example. Comparative Example 2 This comparative example shows the adsorption effect of the FeOOH adsorption material C0 without Ce doping on the extracellular resistance gene (Amp) pollution in water. The specific process is the same as that in Example 1. Comparative Example 3 This comparative example shows the adsorption effect of the Ce-FeOOH adsorption material C1 with a Ce doping amount of 1.5 wt% on the extracellular resistance gene (Amp) pollution in water. The specific process is the same as that in Example 1. Comparative Example 4 The difference between this comparative example and Comparative Example 3 lies in the different Ce doping amounts of Ce-FeOOH. The Ce doping amount of the Ce-FeOOH adsorption material C2 in this comparative example is 4.0 wt%. Comparative Example 5 The difference between this comparative example and Comparative Example 3 lies in the different Ce doping amounts of Ce-FeOOH. The Ce doping amount of the Ce-FeOOH adsorption material C3 in this comparative example is 6.6 wt%. Comparative Example 6 The difference between this comparative example and Comparative Example 3 lies in the different Ce doping amounts of FeOOH. The Ce doping amount of the Ce-FeOOH adsorption material C4 in this comparative example is 8.6 wt%. Comparative Example 7 This comparative example is about the adsorption effect of the Ce-FeOOH adsorbent C5 with a dosage of 10 mg / L on the extracellular antibiotic resistance gene (Amp) pollution in water. The specific process is the same as that in Example 1. Comparative Example 8 The difference between this comparative example and Comparative Example 7 lies in the different dosages of the Ce-FeOOH adsorbent C5. The dosage of the adsorbent C5 in this comparative example is 25 mg / L. Comparative Example 9 The difference between this comparative example and Comparative Example 7 lies in the different dosages of the Ce-FeOOH adsorbent C5. The dosage of the adsorbent C5 in this comparative example is 40 mg / L. Comparative Example 10 The difference between this comparative example and Comparative Example 7 lies in the different dosages of the Ce-FeOOH adsorbent C5. The dosage of the adsorbent C5 in this comparative example is 50 mg / L. Comparative Example 11 This comparative example is about the adsorption effect of the Ce-FeOOH adsorbent C5 with a dosage of 50 mg / L on the extracellular antibiotic resistance gene (Amp) pollution in water when the pH of the water to be treated is 8.0 ± 0.1. The specific process is the same as that in Example 3. Comparative Example 12 The difference between this comparative example and Comparative Example 11 lies in the different pH values of the water to be treated. The pH of the water to be treated in this comparative example is 9.0 ± 0.1. Comparative Example 13 The difference between this comparative example and Comparative Example 11 lies in the different pH values of the water to be treated. The pH of the water to be treated in this comparative example is 10.0 ± 0.1. Comparative Example 14 This comparative example is about the adsorption effect of the Ce-FeOOH adsorbent C5 with a dosage of 50 mg / L on the extracellular antibiotic resistance gene (Amp) pollution in water when the salt content of the water to be treated is 0 mmol / L. The specific process is the same as that in Example 3. Comparative Example 15 This comparative example is about the effect of desorbing and regenerating the Ce-FeOOH adsorbent C5 with 0.05 mol / L NaOH solution for 30 min and simultaneously disinfecting eARG. The specific process is the same as that in Example 3. Comparative Example 16 The difference between this comparative example and Comparative Example 15 is that the desorption and regeneration time in this comparative example is 60 min. Comparative Example 17 The difference between this comparative example and Comparative Example 15 is that the desorption and regeneration time in this comparative example is 120 min. Comparative Example 18 This comparative example shows the desorption regeneration effect of a 0.1 mol / L NaOH solution on the Ce-FeOOH adsorption material C5 for 30 minutes and the synchronous eARG disinfection and killing effect. The specific process is the same as that in Example 3. Comparative Example 19 The difference between this comparative example and Comparative Example 18 is that the desorption regeneration time in this comparative example is 60 minutes. Comparative Example 20 The difference between this comparative example and Comparative Example 18 is that the desorption regeneration time in this comparative example is 120 minutes. Comparative Example 21 This comparative example shows the desorption regeneration effect of a 0.2 mol / L NaOH solution on the Ce-FeOOH adsorption material C5 for 30 minutes and the synchronous eARG disinfection and killing effect. The specific process is the same as that in Example 3. Comparative Example 22 The difference between this comparative example and Comparative Example 21 is that the desorption regeneration time in this comparative example is 60 minutes. Comparative Example 23 The difference between this comparative example and Comparative Example 21 is that the desorption regeneration time in this comparative example is 120 minutes. Comparative Example 24 This comparative example shows the adsorption effect of the metal Zn(II)-doped FeOOH adsorption material Zn-FeOOH on the extracellular resistance gene (Amp) pollution in water. The specific process is the same as that in Example 1. Comparative Example 25 The difference between this comparative example and Comparative Example 24 is that the doped metal in this comparative example is Cu(II). Comparative Example 26 The difference between this comparative example and Comparative Example 24 is that the doped metal in this comparative example is Co(II). Comparative Example 27 The difference between this comparative example and Comparative Example 24 is that the doped metal in this comparative example is Mn(II). Comparative Example 28 The difference between this comparative example and Comparative Example 24 is that the doped metal in this comparative example is Fe(III). Comparative Example 29 This comparative example shows the adsorption effect of the Ce-doped Fe3O4 adsorption material Ce-Fe3O4 on the extracellular resistance gene (Amp) pollution in water. The specific process is the same as that in Example 1. The explanations of the embodiments and comparative examples of the present invention are as follows in conjunction with the accompanying drawings. X-ray photoelectron spectroscopy (XPS), Ce3d, and O1s fine spectra were performed on Ce-FeOOH adsorbent C5 with a Ce doping amount of 10.9 wt% prepared in Example 1 of the present invention and Ce-FeOOH adsorbent C1 with a Ce doping amount of 1.5 wt% prepared in Comparative Example 3, and the results are summarized in Table 1. It can be seen from the analysis of the proportion of elemental components in the full spectrum that with the increase of Ce doping amount, the proportion of Ce content increases from 1.51 wt% to 10.91 wt%. By analyzing the Ce 3d characteristic peaks of adsorbents C1 and C5, it was found that Ce was loaded on the FeOOH surface in the form of mixed valence states of Ce (III) and Ce (IV). This is because during the impregnation process, the oxygen partial pressure in the solution and the local redox environment may promote part of Ce to 3+ Oxidized to Ce 4+ , resulting in the formation of a mixed valence state. And with the increase of Ce doping amount, the proportion of Ce(III) content increased from 17.8% to 30.0%. The O1s characteristic peaks of the adsorbent materials C1 and C5 were fitted by peak separation, showing a significant increase in hydroxyl oxygen (41.12% increased to 51.82%). The results show that the present invention successfully prepared Ce-FeOOH composite materials with different Ce doping amounts by the equal volume impregnation method, and with the increase of Ce doping amount, the proportion of Ce(III) ions gradually increased, and the hydroxyl oxygen content on the surface of the material increased. Through characterization analysis, it can be preliminarily predicted that when Ce replaces Fe on the surface of FeOOH, in order to balance the charge, more surface hydroxyl groups are formed on the surface of FeOOH, increasing the active sites for forming Fe-OP complexes with DNA. Secondly, Ce-OH has a stronger affinity for DNA than Fe-OH, that is, Ce 3+ The ionic radius Much larger than Fe 3+ Its coordination number is higher, and the surface Ce-OH groups expose more active sites due to unsaturated coordination. This makes the doped material have the potential to adsorb DNA through enhanced metal double coordination. Similarly, other lanthanides with similar structures to Ce, such as La 3+ 、Eu 3+ 、Tm 3+ , also has a larger ionic radius and a higher coordination number, which can form more coordination-unsaturated Ln-OH active sites and has great potential in the design of FeOOH-based DNA adsorption materials. Table 1 Summary of XPS full spectrum and Ce 3d and O1s fine spectrum analysis of C1 and C5 adsorbent materials Test index Adsorbent material C1 Adsorbent material C5 Ce element content 1.51％ 10.92％ Ce(III) / (Ce(III)+Ce(IV)) 17.83％ 29.99％ Hydroxyl oxygen content 41.12％ 51.82％ The adsorption effects of the adsorbent C5 prepared in Example 1 of the present invention, the adsorbents C1 - C4 prepared in Comparative Examples 3 - 6, the non - added adsorbent in Comparative Example 1, and the FeOOH adsorbent C0 without Ce doping prepared in Comparative Example 2 on eARGs in water are as follows Figure 1 shown. Under the conditions of an initial Amp concentration of 0.1 mg / L and an adsorbent dosage of 50 mg / L, adsorption phenomena occurred for the adsorbents C1 - C5 and C0. Among them, with the increase in the Ce doping amount, the adsorption effect on Amp was significantly enhanced. At 120 min of adsorption, the Ce - FeOOH adsorbent with a Ce doping amount of 10.9% could adsorb 86.25% of Amp, which was 51.0% higher than that of the FeOOH adsorbent C0 without Ce doping (35.90%). In summary, the doping of Ce on the surface of FeOOH effectively improved the adsorption effect on eARGs, and the adsorption effect was proportional to the doping amount. Examples 2 of the present invention, and Comparative Examples 7 - 10 are about the adsorption effects of the FeOOH adsorbent C5 (Ce doping amount is 10.9%) on eARGs in water under different dosages. As Figure 2 shown, when the initial Amp concentration was 0.1 mg / L, with the increase in the dosage, the adsorption performance of the C5 adsorbent for Amp was also significantly improved. When the dosage was 80 mg / L, 88.23% of Amp could be removed after 30 min of adsorption. When the adsorption time was extended to 120 min, the experimental groups all reached the adsorption equilibrium (Δ adsorption amount < 10%), and no significant desorption phenomenon was observed after equilibrium. Examples 3 - 9 of the present invention are about the adsorption effects of the Ce - FeOOH adsorbent C5 on extracellular resistance genes (Amp) in water at concentrations of 0.025, 0.05, 0.075, 0.1, 0.15, 0.2, and 0.4 mg / L. The adsorption data were fitted using the Langmuir and Freundlich isothermal models, and the FeOOH adsorbent C0 prepared in Comparative Example 2 was used as the control group. As Figure 3 shown, the adsorption data of both adsorbents were well - fitted to the Langmuir model (FeOOH: R 2 = 0.96; Ce - FeOOH: R 2 = 0.94), indicating that their adsorption behavior was dominated by monolayer chemisorption. Among them, the maximum adsorption capacity of the C0 adsorbent was 1.9×10 13 copies / mg, and the maximum adsorption capacity of the C5 adsorbent was significantly increased to 2.2×10 14 copies / mg, which was 11.5 times higher than that of the C0 adsorbent. This difference confirmed that the introduction of Ce effectively enhanced the capture ability of eARGs by regulating the surface adsorption sites and charge distribution characteristics of the material. Examples 10 to 13 and Comparative Examples 11 to 13 of the present invention are the adsorption effects of the Ce-FeOOH adsorbent C5 on eARGs in water at different pH values. As Figure 4 shown, when pH ≤ 7.0 ± 0.1, the adsorption efficiency is greater than 80.0%, and the adsorption effect improves as the pH value decreases. On the contrary, when pH = 8.0 ± 0.1, the adsorption effect decreases by 21.5% compared to when pH = 7 ± 0.1; when pH = 9.0 ± 0.1, the effect decreases by 66.9%, and the adsorption is inhibited when pH = 10.0 ± 0.1. In summary, the Ce-FeOOH doped material has a stable removal effect on eARGs in a relatively wide pH range. Examples 14 to 16 and Comparative Example 14 of the present invention are the adsorption effects of the Ce-FeOOH adsorbent C5 on eARGs in water at different salt contents. As Figure 5 shown, as the NaCl concentration in the water increases, the adsorption effect gradually improves. In the fresh water system (10 mmol / L NaCl), the adsorption effect is 86.9%, which is 10.6% higher than that without ionic strength (66.1%). When the NaCl concentration is 100 - 500 mmol / L, the adsorption effect increases by 32.7 - 33.9%, showing a significant improvement compared to the fresh water environment. In summary, the Ce-FeOOH doped material can adapt to the adsorption and removal of eARG under water conditions with different NaCl concentrations. Therefore, if it is necessary to improve the adsorption and removal effect of Ce-FeOOH on eARGs, the pH value of the water environment or the ionic strength of the water can be appropriately increased. Examples 17 and Comparative Examples 15 to 17 are the effects of synchronous eARG disinfection after the adsorbent C5 adsorbs extracellular resistance gene (Amp) pollution in water and is regenerated with 0.05 mol / L NaOH solution for 360 min, 30 min, 60 min, and 120 min. Examples 18 and Comparative Examples 18 to 20 are the effects of synchronous eARG disinfection after the adsorbent C5 adsorbs extracellular resistance gene (Amp) pollution in water and is regenerated with 0.1 mol / L NaOH solution for 360 min, 30 min, 60 min, and 120 min. Examples 19 and Comparative Examples 21 to 23 are the effects of synchronous eARG disinfection after the adsorbent C5 adsorbs extracellular resistance gene (Amp) pollution in water and is regenerated with 0.2 mol / L NaOH solution for 360 min, 30 min, 60 min, and 120 min. The results are as Figure 6As shown in the figure. When the NaOH concentration is 0.05 mol / L, the degradation efficiency of eARG reaches 23.44% within 30 minutes; when the NaOH concentration is 0.1 mol / L, the degradation efficiency of eARG increases to 53.87% within 30 minutes. When the NaOH concentration is increased to more than 0.2 mol / L, the degradation efficiency of eARG exceeds 83.87% within 30 minutes, achieving effective disinfection of adsorbed eARG. This is attributed to the characteristics of the NaOH solution. On the one hand, the strong base solution can completely dissociate hydroxyl ions in water, complete the replacement of the phosphate groups on the adsorbed eARG, and desorb eARG to realize the regeneration of the adsorbent; at the same time, the high pH of the NaOH solution can cause substantial degradation of eARG. Example 20 of the present invention is the effect of the recycled use of the adsorption material C5 after synchronous eARG disinfection by regenerating the adsorption material with 0.05 mol / L NaOH solution, as Figure 7 shown. After the Ce-FeOOH adsorption material undergoes the adsorption-regeneration cycle experiment period, it has good adsorption performance for eARG. After 5 adsorption-desorption cycles, the adsorption performance of the Ce-FeOOH adsorption material decreases by 15.95%. It shows good recyclability in regeneration. In summary, NaOH can be used as a regenerant to complete the regeneration of the adsorbent in 30 minutes. If effective degradation of eARG is to be completed synchronously during the elution regeneration process, it is necessary to extend the elution time or increase the NaOH concentration. In addition, the Ce-FeOOH adsorbent regenerated by NaOH has good recyclability. Comparative Examples 24 to 28 of the present invention are the comparison of the adsorption effects of adsorption materials doped with different metals on goethite and Comparative Example 29 is the adsorption effect of Ce-doped Fe3O4 adsorption material on Amp, as Figure 8 shown. Under the same concentration of pollutants and the same dosage of adsorbent, the Ce-doped goethite has the best adsorption effect on Amp. The C / C0 at 120 minutes is 0.13, which is significantly lower than that of other metal dopants such as Zn (C / C0 = 0.67), Cu (C / C0 = 0.47), Co (C / C0 = 0.33), Fe (C / C0 = 0.46), Mn (C / C0 = 0.38). This shows that among the material modifications of doping goethite with typical transition metals, lanthanide metals, etc., lanthanide metals represented by Ce have outstanding effects and advantages in the application of modified goethite adsorbents for removing extracellular resistance genes. In addition, when Ce is doped on the surface of other substrates (such as magnetite Fe3O4) for adsorbing eARG, no obvious adsorption effect is observed. It reflects the specificity of the bonding between Ce and FeOOH and its superiority in the application of adsorbing extracellular resistance genes. The above are only the preferred embodiments of the present invention, and the protection scope of the present invention is not limited to the above embodiments. All technical solutions falling within the concept of the present invention belong to the protection scope of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the principle of the present invention, several improvements and refinements should also be regarded as within the protection scope of the present invention.

Claims

1. A cerium-doped goethite adsorption material, characterized in that: The cerium-doped goethite adsorbent Ce-FeOOH is composed of metal cerium Ce doped into goethite FeOOH; Ce is loaded on the surface of FeOOH in the form of a mixed valence state of Ce(III) and Ce(IV), and the proportion of Ce(III) is 17.8-30.0%.

2. The preparation method of the cerium-doped goethite adsorption material according to claim 1, characterized in that, The preparation method includes the following steps: S1. Pretreatment of the precursor: Place FeOOH particles in a low-concentration acid solution, oscillate and react, then wash until neutral, and vacuum dry to obtain pretreated FeOOH. S2. Ce ion loading and purification: Dissolve a cerium salt in water to obtain a cerium salt solution, mix the cerium salt solution and FeOOH, ultrasonically disperse and then oscillate and react to form a composite solution, and finally dialyze the composite solution and vacuum dry to obtain the Ce-doped FeOOH adsorbent.

3. The preparation method according to claim 2, wherein: The low-concentration acid solution described in step S1 is one or more of nitric acid, hydrochloric acid, and sulfuric acid solutions; and / or, The oscillation reaction time in step S2 is 20-40 min, and the vacuum drying temperature is 40-60 °C; and / or, The cerium salt solution described in step S2 is any one or more of cerium chloride, cerium nitrate, cerium sulfate, and their hydrates; and / or, the doping amount of Ce in FeOOH in step S2 is 1.5-10.9 wt%; and / or, The ultrasonic reaction frequency in step S2 is 30-50 kHz, and the time is 20-40 min; the oscillation reaction temperature is 23-26 °C, the rotation speed is 170-190 rpm, and the time is 22-26 h.

4. Use of the Ce-FeOOH adsorbent material according to claim 1 in removing extracellular antibiotic resistance genes (eARGs) in water bodies, characterized in that: The eARGs in the water body are any one or more of extracellular free eARGs gene fragments, plasmids carrying eARGs gene fragments, or genomes.

5. The application according to claim 4, characterized in that, The method for removing eARGs in water by the Ce-FeOOH adsorbent includes the following steps: S1. Adjust the pH of the water body to be treated contaminated with eARGs to (4.0-8.0)±0.1, and use a neutral salt to adjust the salt content of the water body to be treated to ≥10 mmol / L. S2. Disperse the Ce-FeOOH adsorbent in the water body to be treated, oscillate and mix at 23-26 °C and 170-190 rpm for 30-120 min, and centrifuge to separate the Ce-FeOOH-eARGs complex. S3. Immerse the complex in a NaOH solution for desorption to achieve the disinfection of eARGs and the desorption and regeneration of the Ce-FeOOH material.

6. The application according to claim 4, wherein: When the pH of the water body to be treated in step S1 is pH = 7.0±0.1, it is necessary to adjust the salt content of the water body to be treated to ≥10 mmol / L, and the dosage of the Ce-FeOOH adsorbent is ≥80 mg / L.

7. The application according to claim 4, characterized in that: When the water body to be treated in step S1 is one or more of pH < 7.0±0.1 or salt content > 10 mmol / L, select a Ce-FeOOH adsorbent with a Ce doping amount of 10.9%, and adopt one or more methods such as an adsorbent dosage of 50-80 mg / L or shortening the adsorption time to 30-60 min.

8. The application according to claim 4, characterized in that: The concentration of the NaOH solution described in step S3 is 0.05 - 0.2 mol / L, and the desorption time is 30 - 360 min. A synchronous eARG disinfection rate of 75 - 90% can be achieved for the regeneration of the Ce-FeOOH adsorption material, and the number of times the material can be recycled after desorption regeneration is ≥4 times.

9. The application according to claim 4, wherein: The concentration of eARGs in the water to be treated ≤ 1×10 13 copies / L.

10. The application according to claim 4, characterized in that: The adsorption capacity of the Ce-FeOOH adsorbent for removing eARGs from water is ≤ 2.2×10 14 copies / mg.

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