Preparation method of cerium-doped goethite adsorption material and application thereof

Abstract

The application discloses a preparation method of cerium-doped goethite adsorption material and application thereof. The cerium-doped goethite adsorption material Ce-FeOOH is composed of metal cerium Ce doped goethite FeOOH; the Ce doping amount is 1.5-10.9 wt%, Ce is loaded on the surface of FeOOH in the form of mixed valence of Ce(III) and Ce(IV), and the proportion of Ce(III) is 17.8-30.0%. The Ce-FeOOH adsorption material maintains excellent adsorption stability in extracellular antibiotic resistance gene eARGs contaminated water bodies in a wide pH range and high ionic strength. The controllable doping method solves the problems of limited adsorption capacity and pH sensitivity of traditional materials, has high efficiency and economy in the treatment of eARGs pollution in a complex salinity water environment, and provides an innovative solution for water eARGs pollution control.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of environmental functional materials, in particular to a preparation method of a cerium-doped goethite adsorption material and application thereof. The adsorption material is prepared by controllable doping and surface modification technology, and can realize efficient capture and removal of extracellular antibiotic resistance genes under complex water environment conditions, and is suitable for complex water body environment treatment. BACKGROUND

[0002] In recent years, the spread of antibiotic resistance genes (ARGs) in water bodies has become a major challenge in the field of global public health. The World Health Organization (WHO) reported in 2021 that more than 1.27 million people died each year due to drug-resistant bacterial infections, and the number is expected to rise to 10 million by 2050. Among them, extracellular antibiotic resistance genes (eARGs) exist in the form of plasmids, free DNA fragments, and other forms in water environment, and their environmental persistence (half-life can reach several weeks to several months) and horizontal transfer potential are significantly higher than that of intracellular ARGs. eARGs can enter the human body through drinking water, irrigation water and other ways, induce pathogenic bacteria to acquire drug resistance, and seriously threaten the safety of the medical system.

[0003] The current removal technologies for waterborne eARGs mainly include advanced oxidation, biodegradation and adsorption. The technical bottlenecks are as follows: UV, persulfate (PS), Fenton and other advanced oxidation processes can destroy the DNA chain structure through free radical attack, but there are significant defects, such as the risk of by-products. Hydroxyl radical (·OH) attacks organic matter indiscriminately, which may degrade macromolecular eARGs into small fragments (<500 bp) that are more easily taken up by bacteria, thereby promoting resistance transmission. In addition, this method is costly, consumes a lot of electricity when treating water, and requires continuous addition of chemical reagents (such as H2O2), resulting in rising operating costs. The biodegradation method, such as functionalized biofilm technology based on phage and nuclease, has the advantage of specific recognition, but the functional enzymes have poor tolerance in complex environments, and the environmental release of genetically engineered bacteria may also cause environmental safety controversy. In contrast, the adsorption method does not require other energy or reagents, and is simple and green, with great development space. However, traditional adsorbents also have limitations, such as low efficiency and poor selectivity of activated carbon; although nZVI has reduction and degradation ability, it is easily oxidized and inactivated under aerobic conditions, and may cause DNA chain breakage to produce more easily transferred short fragments; eARGs carry strong negative charges (Zeta potential ≈-30 mV) in natural water bodies (pH 7.0-8.0), while the isoelectric point (pHpzc) of traditional metal oxide adsorbents (such as Al2O3 and Fe3O4) is higher than 8.0, resulting in electrostatic repulsion; commercial anion exchange resins can capture DNA through electrostatic attraction, but are significantly affected by humic acid competitive adsorption. Therefore, it is necessary to seek more effective and reliable adsorbents to achieve efficient removal of free eARGs.

[0004] Goethite (FeOOH) is considered as a potential adsorbent due to its environmental friendliness and rich surface hydroxyl groups, but its inherent characteristics seriously limit its adsorption efficiency for eARGs, such as mismatch of surface charge and pore size, environmental sensitivity, etc. Based on the above defects, cerium (Ce) is selected as a doping element, which can break through the limitations of traditional adsorbents through the following mechanisms: (1) active site enrichment and coordination bonding. The doping of Ce element can increase the surface hydroxyl group density or introduce oxygen vacancy active sites. Ce-OH groups (pKa ≈ 6.8) are preferentially protonated at physiological pH, becoming strong coordination sites for DNA phosphate groups (pKa ≈ 1.5). The Ce-O-Fe bond forms an electron transfer channel, enhancing the π-π stacking effect on DNA bases and improving adsorption. The formation of oxygen vacancies and the exposure of surrounding unpaired Ce(III) / Fe(III) also provide more adsorption sites for eARGs. (2) surface charge optimization and electrostatic attraction enhancement. Ce 3+ Substituting Fe in the FeOOH lattice 3+The doping of Ce enhances the protonation tendency, lowers the isoelectric point of the material, and increases the electrostatic attraction to the negatively charged eARGs.

[0005] Based on the above theoretical basis, the Ce-doped goethite adsorbent Ce-FeOOH is expected to achieve efficient, stable, and sustainable eARGs removal through the synergistic mechanism of coordination bond strengthening, surface charge optimization, and interference resistance enhancement. SUMMARY

[0006] The technical problem to be solved: The present application aims to solve the problems of low removal efficiency and poor environmental adaptability of existing adsorbents for extracellular antibiotic resistance gene removal in water bodies. It provides a cerium-doped goethite adsorbent (Ce-FeOOH) and a preparation method thereof for repairing water bodies contaminated with extracellular antibiotic resistance genes.

[0007] Technical solution: A cerium-doped goethite adsorbent and a preparation method thereof.

[0008] The cerium-doped goethite adsorbent Ce-FeOOH is composed of metal cerium Ce doped goethite FeOOH; Ce is loaded on the surface of FeOOH in the form of mixed valence of Ce(III) and Ce(IV), and the proportion of Ce(III) is 17.8-30.0%.

[0009] The preparation method of the cerium-doped goethite adsorbent includes the following steps:

[0010] S1. Precursor treatment: After oscillation reaction in a low-concentration acid solution, the FeOOH particles are washed to neutral and vacuum dried to obtain pretreated FeOOH;

[0011] S2. Ce ion loading and purification: Dissolve cerium salt in water to obtain a cerium salt solution, mix the cerium salt solution and FeOOH, ultrasonically disperse, and then oscillate to form a composite solution. Finally, dialyze the composite solution and vacuum dry to obtain the Ce-FeOOH adsorbent.

[0012] As a preferred, the low-concentration acid solution in step S1 is one or more of nitric acid, hydrochloric acid, and sulfuric acid solution;

[0013] As a preferred, the oscillation reaction time in step S1 is 20-40 min, and the vacuum drying temperature is 40-60℃.

[0014] As a preferred, the cerium salt solution in step S2 is any one or more of cerium chloride, cerium nitrate, cerium sulfate, and their hydrates. As a preferred, the Ce doping amount of the Ce-FeOOH adsorbent in step S2 is 1.5-10.9wt%.

[0015] Further, the Ce doping amount of the Ce-FeOOH adsorbent material in step S2 is 10.9wt%.

[0016] Preferably, the ultrasonic reaction in step S2 is performed at a frequency of 30-50 kHz for 20-40 min, and the oscillation reaction is performed at a temperature of 23-26℃, a rotation speed of 170-190 rpm for 22-26 h.

[0017] Application of the Ce-FeOOH adsorbent material in removing extracellular antibiotic resistance genes (eARGs) in water bodies.

[0018] The method for removing extracellular antibiotic resistance genes (eARGs) in water bodies by using the Ce-FeOOH adsorbent material comprises the following steps:

[0019] S1. Adjusting the pH of the water body to be treated containing eARGs pollution to (4.0-8.0) ± 0.1, and adjusting the salt content of the water body to be treated to ≥10 mmol / L by using a neutral salt;

[0020] S2. Dispersing the Ce-FeOOH adsorbent material in the water body to be treated, oscillating and mixing at 23-26℃ and 170-190 rpm for 30-120 min, and centrifuging the Ce-FeOOH-eARGs complex;

[0021] S3. Immersing the complex in a NaOH solution to kill the eARGs in the water body and regenerate the Ce-FeOOH material.

[0022] Preferably, the pH of the water body to be treated in step S1 is (4.0-7.0) ± 0.1.

[0023] Further, the pH of the water body to be treated in step S1 is ≤7.0 ± 0.1.

[0024] Preferably, the salt content of the water body to be treated in step S1 is 10-500 mmol / L.

[0025] Further, the salt content of the water body to be treated in step S1 is ≥10 mmol / L.

[0026] Preferably, the amount of the Ce-FeOOH adsorbent material added to the water body to be treated in step S2 is 10-80 mg / L.

[0027] Further, the amount of the Ce-FeOOH adsorbent material added to the water body to be treated in step S2 is ≥80 mg / L.

[0028] Preferably, the adsorption time of the Ce-FeOOH adsorbent material in step S2 for removing eARGs pollution in the water body is 0-360 min.

[0029] Further, the adsorption time of the Ce-FeOOH adsorbent for removing eARGs pollution in the water body in step S2 is ≥60 min.

[0030] As preferred, when the pH of the water body to be treated in step S2 is 7.0±0.1, the salt content of the water body to be treated needs to be adjusted to ≥10 mmol / L, and the dosage of the Ce-FeOOH adsorbent is ≥80 mg / L.

[0031] As preferred, when the pH of the water body to be treated in step S2 is <7.0±0.1 or the salt content of the water body to be treated is >10 mmol / L, the Ce-FeOOH adsorbent with a Ce doping amount of 10.9% is selected, and one or more of the following methods is adopted: the dosage of the adsorbent is 50-80 mg / L or the adsorption time is shortened to 30-60 min.

[0032] As preferred, 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.

[0033] The Ce-FeOOH adsorbent described above is applied in the repair of water bodies polluted by extracellular antibiotic resistance genes.

[0034] Beneficial effects

[0035] Compared with traditional adsorbents, the present application has the following beneficial effects:

[0036] 1. Improved adsorption efficiency: dual optimization of fast kinetics and high adsorption capacity is achieved, not only strong chelation of eARGs phosphate groups is achieved, but also the adsorption equilibrium time is shortened.

[0037] 2. Improved environmental adaptability: the modified material can adapt to a wide pH tolerance range, breaking through the bottleneck of pH limitation of traditional materials, and performing excellently in the application of fresh water, medium salt water and salt water of various salinity.

[0038] 3. Green sustainability: low-cost raw materials are used in combination with low-carbon preparation process, which significantly reduces the carbon emissions in the production process of the material, and through precise control of process parameters to control the material structure, a solution with high efficiency, sustainability and green for eARGs pollution treatment is provided. BRIEF DESCRIPTION OF DRAWINGS

[0039] Figure 1 Adsorption effects of Ce-FeOOH adsorbents C0-C5 with different Ce doping amounts on eARGs in water bodies;

[0040] Figure 2 Ce-FeOOH adsorbent C5 with different dosages on the adsorption effect of eARGs in water;

[0041] Figure 3 Langmuir and Freundlich adsorption models for FeOOH and Ce-FeOOH adsorbent C5 on the adsorption effect of eARGs in water with different concentrations;

[0042] Figure 4 Ce-FeOOH adsorbent C5 with different pH values on the adsorption effect of eARGs in water;

[0043] Figure 5 Ce-FeOOH adsorbent C5 with different NaCl concentrations on the adsorption effect of eARGs in water;

[0044] Figure 6 Different concentrations of NaOH on the killing effect of eARGs adsorbed by Ce-FeOOH adsorbent C5;

[0045] Figure 7 Ce-FeOOH adsorbent C5 after NaOH desorption regeneration for recycling performance;

[0046] Figure 8 Comparison of different metal-doped FeOOH and Ce-doped Fe3O4 on the adsorption effect of eARGs in water. DETAILED DESCRIPTION

[0047] In order to further understand the present application, the preferred embodiments of the present application are described below in conjunction with examples.

[0048] Specific preferred examples are as follows:

[0049] Example 1

[0050] This example is the preparation method of Ce-doped FeOOH adsorbent C5 with a Ce doping amount of 10.9wt% and its adsorption effect on extracellular resistance gene (Amp) pollution in water, including the following steps:

[0051] (1) Preparation of Ce-doped FeOOH adsorbent C5 with a Ce doping amount of 10.9wt%:

[0052] S1. Precursor treatment: put FeOOH particles into 0.1mol / L nitric acid solution and shake for 30min, wash to neutral (pH=7.0±0.1), and vacuum dry at 50℃ to obtain pretreated FeOOH;

[0053] S2. Ce ion loading and purification: accurately weigh cerium chloride heptahydrate (CeCl3·7H2O, 99.9%) and dissolve it in 50 mL of deionized water, add the pretreated FeOOH, ultrasonically disperse for 30 min at 40 kHz, and then form a composite solution by reacting at 25°C and 180 rpm for 24 h; transfer the composite solution into a dialysis bag with a molecular weight cut-off of 5-10 kDa, and dialyze in a 2 L ultrapure water system to remove unstable impurities; centrifuge to collect the precipitate, and then wash it with ultrapure water in three stages (repeat the centrifugation-resuspension cycle 3 times), and vacuum dry at 50°C to obtain Ce-FeOOH adsorbent C5 with a Ce doping amount of 10.9 wt%;

[0054] (2) Extraction of eARGs:

[0055] S1. Use plasmid DH5α E. coli carrying an ampicillin resistance gene (Amp) as the template strain. Take 0.1 mL of -80°C glycerol-stored engineering bacteria liquid, inoculate in 500 mL of LB liquid medium containing 100 μg / mL Amp, and incubate at 37°C and 180 rpm for 16 h to the logarithmic growth phase (OD 600 = 0.6-0.8);

[0056] S2. Centrifuge the bacteria at 4000 x g at 4°C for 10 min to collect the bacteria and extract the plasmid for purification. After the extracted plasmid is detected for plasmid integrity by a real-time fluorescence quantitative PCR system (qPCR), confirm the plasmid purity (A 260 / A 280 = 1.82±0.05), and store it at -80°C in an ultra-low temperature refrigerator;

[0057] (3) Adsorption experiment of Ce-FeOOH adsorbent C5 on water contaminated with extracellular resistance genes (Amp):

[0058] S1. Establish a 0.4 mL reaction system in a 2.0 mL sterile enzyme-free EP tube, which contains 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;

[0059] S2. Shake the reaction system at 25°C and 180 rpm, take samples at preset time points (0-360 min), centrifuge at 4°C and 12000 x g for 5 min, collect the supernatant, and detect it by qPCR. According to the standard curve, calculate the residual Amp resistance gene concentration.

[0060] Example 2

[0061] This example is the adsorption effect of Ce-FeOOH adsorbent C5 with a dosage of 80 mg / L on water contaminated with extracellular resistance genes (Amp), and the specific process is the same as that in Example 1.

[0062] Example 3

[0063] This example is the adsorption effect of Ce-FeOOH adsorbent C5 on extracellular resistance gene (Amp) in water when the concentration of extracellular resistance gene (Amp) in water is 0.025 mg / L, including the following steps:

[0064] S1. The preparation method of Ce-FeOOH adsorbent C5 is the same as that in Example 1;

[0065] S2. A 0.2 mL reaction system was established in a 2.0 mL sterile and enzyme-free EP tube, which contained 0.025 mg / L Amp and 40 mg / L C5 adsorbent; the pH of the reaction system was 7.0±0.1, and the salt content was 10 mmol / L;

[0066] S3. The reaction system was reacted at 25℃ with 180 rpm oscillation for 120 min, and after centrifugation at 4℃ and 12000×g for 5 min, the supernatant was collected for qPCR detection, and the residual Amp resistance gene concentration was calculated according to the standard curve;

[0067] S4. The adsorption data was fitted by Langmuir and Freundlich adsorption models: the formula of Langmuir adsorption model is Q = (Q m bp) / (1+bp), wherein: Q is the adsorption amount (mmol / g), Q m is the saturated adsorption amount (mmol / g), b is the adsorption equilibrium constant, and p is the partial pressure of the component (kPa); the formula of Freundlich adsorption model is Q = (Q m bp n ) / (1+bp n ), wherein: n is the homogeneous index.

[0068] Example 4

[0069] The difference between this example and Example 3 is that the concentration of extracellular resistance gene (Amp) in water is different, and the concentration of Amp in this example is 0.05 mg / L.

[0070] Example 5

[0071] The difference between this example and Example 3 is that the concentration of extracellular resistance gene (Amp) in water is different, and the concentration of Amp in this example is 0.075 mg / L.

[0072] Example 6

[0073] The difference between this example and Example 3 is that the concentration of extracellular resistance gene (Amp) in water is different, and the concentration of Amp in this example is 0.1 mg / L.

[0074] Example 7

[0075] The difference between this example and Example 3 is the concentration of extracellular resistance gene (Amp) in water, and the concentration of Amp in this example is 0.15 mg / L.

[0076] Example 8

[0077] The difference between this example and Example 3 is the concentration of extracellular resistance gene (Amp) in water, and the concentration of Amp in this example is 0.2 mg / L.

[0078] Example 9

[0079] The difference between this example and Example 3 is the concentration of extracellular resistance gene (Amp) in water, and the concentration of Amp in this example is 0.4 mg / L.

[0080] Example 10

[0081] This example is the adsorption effect of Ce-FeOOH adsorbent C5 on extracellular resistance gene (Amp) pollution in water when the pH of the water to be treated is 4.0±0.1 and the dosage is 50 mg / L. The specific process is the same as Example 3.

[0082] Example 11

[0083] The difference between this example and Example 10 is the pH of the water to be treated, and the pH of the water to be treated in this example is 5.0±0.1.

[0084] Example 12

[0085] The difference between this example and Example 10 is the pH of the water to be treated, and the pH of the water to be treated in this example is 6.0±0.1.

[0086] Example 13

[0087] The difference between this example and Example 10 is the pH of the water to be treated, and the pH of the water to be treated in this example is 7.0±0.1.

[0088] Example 14

[0089] This example is the adsorption effect of Ce-FeOOH adsorbent C5 on extracellular resistance gene (Amp) pollution in water when the salt content of the water to be treated is 10 mmol / L and the dosage is 50 mg / L. The specific process is the same as Example 3.

[0090] Example 15

[0091] The difference between the embodiment and embodiment 14 is that the salt content of the water body to be treated is different, and the salt content of the water body to be treated in the embodiment is 100 mmol / L.

[0092] Embodiment 16

[0093] The difference between the embodiment and embodiment 14 is that the salt content of the water body to be treated is different, and the salt content of the water body to be treated in the embodiment is 500 mmol / L.

[0094] Embodiment 17

[0095] The embodiment is the effect of 0.05 mol / L NaOH solution on the desorption regeneration of Ce-FeOOH adsorbent C5 for 360 min synchronous eARG disinfection, and the specific process is the same as that of embodiment 3.

[0096] Embodiment 18

[0097] The difference between the embodiment and embodiment 17 is that the concentration of NaOH solution in the embodiment is 0.1 mol / L.

[0098] Embodiment 19

[0099] The difference between the embodiment and embodiment 17 is that the concentration of NaOH solution in the embodiment is 0.2 mol / L.

[0100] Embodiment 20

[0101] The embodiment is the effect of Ce-FeOOH adsorbent C5 on the adsorption of extracellular resistance gene (Amp) pollution in water, and then the adsorbent is regenerated by 0.05 mol / L NaOH solution, and then the effect of synchronous eARG disinfection, and the specific process is the same as that of embodiment 3.

[0102] In order to further illustrate the technical effect of the present application, the present application also provides a comparative example, which is as follows:

[0103] Comparative Example 1

[0104] In the comparative example, the eARGs contaminated water body does not add adsorbent.

[0105] Comparative Example 2

[0106] The comparative example is the adsorption effect of FeOOH adsorbent C0 without Ce doping on the extracellular resistance gene (Amp) pollution in water, and the specific process is the same as that of embodiment 1.

[0107] Comparative Example 3

[0108] The comparative example is the adsorption effect of Ce-FeOOH adsorbent C1 with a Ce doping amount of 1.5 wt% on the extracellular resistance gene (Amp) pollution in water, and the specific process is the same as that of embodiment 1.

[0109] Comparative Example 4

[0110] The difference between the present comparative example and Comparative Example 3 is that the Ce doping amount of Ce-FeOOH is different, and the Ce doping amount of Ce-FeOOH adsorbent C2 in the present comparative example is 4.0 wt%.

[0111] Comparative Example 5

[0112] The difference between the present comparative example and Comparative Example 3 is that the Ce doping amount of Ce-FeOOH is different, and the Ce doping amount of Ce-FeOOH adsorbent C3 in the present comparative example is 6.6 wt%.

[0113] Comparative Example 6

[0114] The difference between the present comparative example and Comparative Example 3 is that the Ce doping amount of Ce-FeOOH is different, and the Ce doping amount of Ce-FeOOH adsorbent C4 in the present comparative example is 8.6 wt%.

[0115] Comparative Example 7

[0116] The present comparative example is the adsorption effect of Ce-FeOOH adsorbent C5 on extracellular resistance gene (Amp) pollution in water with a dosage of 10 mg / L, and the specific process is the same as that of Example 1.

[0117] Comparative Example 8

[0118] The difference between the present comparative example and Comparative Example 7 is that the dosage of Ce-FeOOH adsorbent C5 is different, and the dosage of adsorbent C5 in the present comparative example is 25 mg / L.

[0119] Comparative Example 9

[0120] The difference between the present comparative example and Comparative Example 7 is that the dosage of Ce-FeOOH adsorbent C5 is different, and the dosage of adsorbent C5 in the present comparative example is 40 mg / L.

[0121] Comparative Example 10

[0122] The difference between the present comparative example and Comparative Example 7 is that the dosage of Ce-FeOOH adsorbent C5 is different, and the dosage of adsorbent C5 in the present comparative example is 50 mg / L.

[0123] Comparative Example 11

[0124] The present comparative example is the adsorption effect of Ce-FeOOH adsorbent C5 on extracellular resistance gene (Amp) pollution in water with a dosage of 50 mg / L when the pH of the water to be treated is 8.0±0.1, and the specific process is the same as that of Example 3.

[0125] Comparative Example 12

[0126] The difference between the present comparative example and Comparative Example 11 is that the pH of the water body to be treated is different, and the pH of the water body to be treated in the present comparative example is pH = 9.0 ± 0.1.

[0127] Comparative Example 13

[0128] The difference between the present comparative example and Comparative Example 11 is that the pH of the water body to be treated is different, and the pH of the water body to be treated in the present comparative example is pH = 10.0 ± 0.1.

[0129] Comparative Example 14

[0130] The present comparative example is the adsorption effect of Ce-FeOOH adsorbent C5 with a dosage of 50 mg / L on extracellular resistance gene (Amp) pollution in water when the salt content of the water body to be treated is 0 mmol / L, and the specific process is the same as that of Example 3.

[0131] Comparative Example 15

[0132] The present comparative example is the effect of 0.05 mol / L NaOH solution on the desorption regeneration of Ce-FeOOH adsorbent C5 for 30 min and the simultaneous eARG killing effect, and the specific process is the same as that of Example 3.

[0133] Comparative Example 16

[0134] The difference between the present comparative example and Comparative Example 15 is that the desorption regeneration time in the present comparative example is 60 min.

[0135] Comparative Example 17

[0136] The difference between the present comparative example and Comparative Example 15 is that the desorption regeneration time in the present comparative example is 120 min.

[0137] Comparative Example 18

[0138] The present comparative example is the effect of 0.1 mol / L NaOH solution on the desorption regeneration of Ce-FeOOH adsorbent C5 for 30 min and the simultaneous eARG killing effect, and the specific process is the same as that of Example 3.

[0139] Comparative Example 19

[0140] The difference between the present comparative example and Comparative Example 18 is that the desorption regeneration time in the present comparative example is 60 min.

[0141] Comparative Example 20

[0142] The difference between the present comparative example and Comparative Example 18 is that the desorption regeneration time in the present comparative example is 120 min.

[0143] Comparative Example 21

[0144] The comparative example is the effect of 0.2 mol / L NaOH solution on desorption regeneration of Ce-FeOOH adsorbent C5 for 30 min and simultaneous eARG disinfection, and the specific process is the same as that of example 3.

[0145] Comparative example 22

[0146] The difference between the comparative example and comparative example 21 is that the desorption regeneration time in the comparative example is 60 min.

[0147] Comparative example 23

[0148] The difference between the comparative example and comparative example 21 is that the desorption regeneration time in the comparative example is 120 min.

[0149] Comparative example 24

[0150] The comparative example is the adsorption effect of metal Zn(II)-doped FeOOH adsorbent Zn-FeOOH on extracellular resistance gene (Amp) pollution in water, and the specific process is the same as that of example 1.

[0151] Comparative example 25

[0152] The difference between the comparative example and comparative example 24 is that the metal doped in the comparative example is Cu(II).

[0153] Comparative example 26

[0154] The difference between the comparative example and comparative example 24 is that the metal doped in the comparative example is Co(II).

[0155] Comparative example 27

[0156] The difference between the comparative example and comparative example 24 is that the metal doped in the comparative example is Mn(II).

[0157] Comparative example 28

[0158] The difference between the comparative example and comparative example 24 is that the metal doped in the comparative example is Fe(III).

[0159] Comparative example 29

[0160] The comparative example is the adsorption effect of Ce-doped Fe3O4 adsorbent Ce-Fe3O4 on extracellular resistance gene (Amp) pollution in water, and the specific process is the same as that of example 1.

[0161] The embodiments, comparative examples of the present application are explained as follows in combination with the drawings.

[0162] X-ray photoelectron spectroscopy (XPS), Ce 3d, and O 1s fine spectra were performed on Ce-FeOOH adsorbent material C5 with a Ce doping content of 10.9 wt% prepared in Example 1 of this invention and Ce-FeOOH adsorbent material C1 with a Ce doping content of 1.5 wt% prepared in Comparative Example 3. The results are summarized in Table 1. Analysis of the elemental composition of the full spectrum shows that the Ce content increases with increasing Ce doping content, from 1.51 wt% to 10.91 wt%. Analysis of the Ce 3d characteristic peaks of adsorbent materials C1 and C5 revealed that Ce is loaded on the FeOOH surface in a mixed valence state of Ce(III) and Ce(IV). This is because during the impregnation process, the oxygen partial pressure and local redox environment in the solution may promote the partial loading of Ce. 3+ Oxidized to Ce 4+ This leads to the formation of mixed valence states. Furthermore, with increasing Ce doping concentration, the Ce(III) content increases from 17.8% to 30.0%. Peak fitting of the O1s characteristic peaks of C1 and C5 adsorbents reveals a significant increase in hydroxyl oxygen (from 41.12% to 51.82%). These results demonstrate that this invention successfully prepared Ce-FeOOH composite materials with different Ce doping concentrations via an equal-volume impregnation method. With increasing Ce doping concentration, the proportion of Ce(III) ions gradually increases, and the hydroxyl oxygen content on the material surface increases. Characterization analysis preliminarily predicts that when Ce replaces Fe on the FeOOH surface, more surface hydroxyl groups are formed on the FeOOH surface to balance the charge, increasing the active sites for Fe-OP complexation with DNA. Secondly, Ce-OH also exhibits a stronger affinity for DNA than Fe-OH, meaning Ce... 3+ ionic radius Much larger than Fe 3+ Its higher coordination number and the unsaturated Ce-OH groups on the surface expose more active sites, giving the doped material the potential to adsorb DNA through enhanced metal-to-coordination interactions. Similarly, other lanthanides with similar structures to Ce, such as La... 3+ Eu 3+ Tm 3+ It also has a larger ionic radius. With a higher coordination number, it can form more coordinate-unsaturated Ln-OH active sites, which has great potential in the design of FeOOH-based DNA adsorbent materials.

[0163] Table 1. Summary of XPS full spectrum and Ce 3d, O 1s fine spectrum analysis of C1 and C5 adsorbent materials

[0164] Test criteria 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％

[0165] The adsorption effect of the adsorbent C5 prepared in Example 1 of the present application and the adsorbents C1-C4 prepared in Comparative Examples 3-6 and Comparative Example 1 without adding the adsorbent and the FeOOH adsorbent C0 without doping Ce prepared in Comparative Example 2 on eARGs in water is shown in Table 1. Figure 1 Under the conditions of the initial Amp concentration of 0.1 mg / L and the adsorbent dosage of 50 mg / L, the adsorbents C1-C5 and C0 all have the adsorption phenomenon. Among them, with the increase of the Ce doping amount, the adsorption effect on Amp is significantly enhanced. The Ce-FeOOH adsorbent with the Ce doping amount of 10.9% can adsorb 86.25% of Amp at 120 min, which is increased by 51.0% compared with the FeOOH adsorbent C0 without doping Ce (35.90%). In summary, the doping of Ce on the surface of FeOOH effectively improves the adsorption effect on eARGs, and the adsorption effect is proportional to the doping amount.

[0166] Example 2 and Comparative Examples 7-10 of the present application are the adsorption effect of the FeOOH adsorbent C5 (Ce doping amount of 10.9%) on eARGs in water under different dosages. As shown in Table 2, Figure 2 Under the condition of the initial Amp concentration of 0.1 mg / L, with the increase of the dosage, the adsorption performance of the C5 adsorbent on Amp is also obviously improved. When the dosage is 80 mg / L, 88.23% of Amp can be removed at 30 min. When the adsorption time is prolonged to 120 min, the experimental groups all reach the adsorption equilibrium (Δadsorption amount <10%), and no significant desorption phenomenon is observed after the equilibrium.

[0167] Examples 3-9 of the present application are the adsorption effect of the Ce-FeOOH adsorbent C5 on the concentration of extracellular resistance genes (Amp) in water of 0.025, 0.05, 0.075, 0.1, 0.15, 0.2 and 0.4 mg / L, and the adsorption data is fitted by using the Langmuir and Freundlich isothermal models, and the FeOOH adsorbent C0 prepared in Comparative Example 2 is used as the control group. As shown in Table 3, Figure 3 The adsorption data of the two kinds of adsorbents are well fitted to the Langmuir model (FeOOH: R 2 =0.96; Ce-FeOOH: R 2 =0.94), indicating that the adsorption behavior is dominated by monolayer chemical adsorption. Among them, the maximum adsorption capacity of the C0 adsorbent is 1.9×10 13 copies / mg, and the maximum adsorption capacity of the C5 adsorbent is significantly improved to 2.2×10 14 copies / mg, which is increased by 11.5 times compared with the C0 adsorbent. This difference confirms that the introduction of Ce effectively enhances the capture capacity of eARGs by regulating the adsorption sites and charge distribution characteristics on the surface of the material.

[0168] Examples 10-13 and Comparative Examples 11-13 of this invention demonstrate the adsorption effect of Ce-FeOOH adsorbent C5 on eARGs in water at different pH values. Figure 4 As shown, when pH ≤ 7.0 ± 0.1, the adsorption efficiency is greater than 80.0%, and the adsorption effect increases with decreasing pH. Conversely, when pH = 8.0 ± 0.1, the adsorption effect decreases by 21.5% compared to pH = 7 ± 0.1; when pH = 9.0 ± 0.1, the effect decreases by 66.9%; and when pH = 10.0 ± 0.1, adsorption is inhibited. In summary, Ce-FeOOH doped materials exhibit stable removal efficiency for eARGs over a wide pH range.

[0169] Examples 14-16 and Comparative Example 14 of this invention demonstrate the adsorption effect of Ce-FeOOH adsorbent C5 on eARGs in water under different salinity levels. Figure 5 As shown, the adsorption effect gradually increases with the increase of NaCl concentration in the water. In the freshwater 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%, which is significantly better than that in the freshwater environment. In summary, Ce-FeOOH doped materials can adapt to the adsorption and removal of eARGs under different NaCl concentration conditions in water. Therefore, if it is necessary to improve the adsorption and removal effect of Ce-FeOOH on eARGs, the pH value or ionic strength of the water environment can be appropriately increased.

[0170] Examples 17 and Comparative Examples 15-17 demonstrate the effect of adsorbent C5 on the adsorption of extracellular resistance gene (Amp) contamination in water, followed by regeneration with 0.05 mol / L NaOH solution for 360 min, 30 min, 60 min, and 120 min, with simultaneous eARG elimination. Examples 18 and Comparative Examples 18-20 demonstrate the effect of adsorbent C5 on the adsorption of extracellular resistance gene (Amp) contamination in water, followed by regeneration with 0.1 mol / L NaOH solution for 360 min, 30 min, 60 min, and 120 min, with simultaneous eARG elimination. Examples 19 and Comparative Examples 21-23 demonstrate the effect of adsorbent C5 on the adsorption of extracellular resistance gene (Amp) contamination in water, followed by regeneration with 0.2 mol / L NaOH solution for 360 min, 30 min, 60 min, and 120 min, with simultaneous eARG elimination. The results are as follows. Figure 6As shown. When the concentration of NaOH is 0.05 mol / L, the degradation efficiency of eARG reaches 23.44% within 30 min; when the concentration of NaOH is 0.1 mol / L, the degradation efficiency of eARG increases to 53.87% within 30 min. When the concentration of NaOH is higher than 0.2 mol / L, the degradation efficiency of eARG exceeds 83.87% within 30 min, realizing the effective disinfection of the adsorbed eARG. This is due to the characteristics of NaOH solution. On the one hand, the strong alkali solution can completely dissociate hydroxyl ions in water, complete the replacement with the phosphoric acid group on the adsorbed eARG, and realize the regeneration of the adsorbent; at the same time, the high pH of the NaOH solution can cause substantial degradation of eARG.

[0171] The embodiment 20 of the present application is the effect of recycling use of the adsorbent material C5 after regeneration and synchronous eARG disinfection by 0.05 mol / L NaOH solution, as shown in Figure 7 The Ce-FeOOH adsorbent material has good adsorption performance for eARG after the adsorption-regeneration cycle experiment period. After 5 adsorption-desorption cycles, the adsorption performance of the Ce-FeOOH adsorbent material is reduced by 15.95%. It shows good regeneration and recycling performance.

[0172] In summary, NaOH as a regeneration solution can complete the regeneration of the adsorbent within 30 min. If it is desired to complete the effective degradation of eARG during the elution and regeneration process, it is necessary to prolong the elution time or increase the concentration of NaOH. In addition, the Ce-FeOOH adsorbent regenerated by NaOH has good recycling performance.

[0173] The comparative examples 24-28 of the present application are adsorbent materials doped with different metals goethite, and the comparative example 29 is a Ce-doped Fe3O4 adsorbent material. The adsorption effect of Amp is compared, as shown in Figure 8 Test criteria Adsorbent material C1 Adsorbent material C5 Ce element content Ce(III) / (Ce(III) + Ce(IV)) Hydroxyl oxygen content Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Under the same concentration of pollutants and the same adsorbent dosage, the Ce-doped goethite has the best adsorption effect on Amp, and the C / C0 at 120 min is 0.13, which is significantly lower than other metals such as Zn (C / C0=0.67), Cu (C / C0=0.47), Co (C / C0=0.33), Fe (C / C0=0.46), and Mn (C / C0=0.38). This shows that in the modification of goethite materials doped with typical transition metals and lanthanide metals, the lanthanide metal represented by Ce has outstanding effect and advantage in the application of modified goethite adsorbent in removing extracellular resistance genes. In addition, the Ce-doped on the surface of other substrates (such as magnetite Fe3O4) is used for adsorbing eARG, and no obvious adsorption effect is observed. This reflects the specificity of the bonding of Ce and FeOOH and the superiority in the application of adsorbing extracellular resistance genes.

[0174] The above merely describes the preferred embodiments of the present application, and the protection scope of the present application is not limited to the above-described embodiments. Any technical solution falling within the concept of the present application shall fall within the protection scope of the present application. It should be noted that, for ordinary skilled persons in the art, some improvements and refinements without departing from the principles of the present application shall also be considered as falling within the protection scope of the present application.

Claims

1. A cerium-doped goethite adsorbent material, characterized by: The cerium-doped goethite adsorption material Ce-FeOOH is composed of metal cerium Ce doped goethite FeOOH; Ce is loaded on the surface of FeOOH in the form of mixed valence 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 adsorption material Ce-FeOOH comprises the following steps: S1. precursor treatment: after the FeOOH particles are placed in a low-concentration acid solution and oscillated, they are washed to neutral and vacuum dried to obtain pretreated FeOOH; S2. Ce ion loading and purification: cerium salt is dissolved in water to obtain a cerium salt solution, the cerium salt solution and FeOOH are mixed, ultrasonic dispersion is performed, and then oscillation reaction is performed to form a composite solution, and finally the composite solution is dialyzed and vacuum dried to obtain a Ce-doped FeOOH adsorption material.

2. The cerium-doped needle iron oxide adsorbent material of claim 1, wherein: The low-concentration acid solution in step S1 is one or more of nitric acid, hydrochloric acid, and sulfuric acid solution; 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 in step S2 is any one or more of cerium chloride, cerium nitrate, cerium sulfate, and hydrates thereof; and / or, The doping amount of Ce in FeOOH in step S2 is 1.5-10.9 wt%; and / or, The ultrasonic dispersion 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.

3. Use of the Ce-FeOOH adsorbent material according to claim 1 for the removal of 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.

4. Use according to claim 3, characterized in that, The method for removing eARGs in a water body by using Ce-FeOOH adsorption material comprises the following steps: S1. Adjust the pH of the eARGs-contaminated water body to be treated to (4.0-8.0) ± 0.1, and adjust the salt content of the water body to be treated to be ≥10 mmol / L by using a neutral salt; S2. Disperse the Ce-FeOOH adsorption 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 the Ce-FeOOH-eARGs composite; S3. Soak the composite in a NaOH solution to desorb and regenerate the Ce-FeOOH material, thereby killing the eARGs.

5. Use according to claim 4, characterized in that: When the pH of the water body to be treated is 7.0 ± 0.1, the salt content of the water body to be treated needs to be adjusted to be ≥10 mmol / L, and the amount of Ce-FeOOH adsorption material to be added is ≥80 mg / L.

6. Use according to claim 4, characterized in that: When the pH of the water body to be treated is <7.0 ± 0.1 or the salt content of the water body to be treated is >10 mmol / L, use the Ce-FeOOH adsorption material with a Ce doping amount of 10.9%, and use one or more of the adsorption material in an amount of 50-80 mg / L or shorten the adsorption time to 30-60 min.

7. Use according to claim 4, characterized in that: The concentration of the NaOH solution in step S3 is 0.05-0.2 mol / L, and the desorption time is 30-360 min, so that the regeneration of the Ce-FeOOH adsorption material can be realized, and the sterilization rate of 75-90% of eARG can be achieved at the same time; after the desorption and regeneration, the material can be recycled for more than 4 times.

8. Use according to claim 4, characterized in that: The concentration of eARGs in the water body to be treated is ≤ 1 x 10 13 copies / L.

9. Use according to claim 3, characterized in that: The Ce-FeOOH adsorption material removes eARGs in water bodies with an adsorption capacity of ≤ 2.2 x 10 14 copies / mg.

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