Preparation method and application of cerium-doped metal-organic framework for removing organophosphorus

Abstract

The application discloses a preparation method and application of a cerium-doped metal organic framework material for removing organic phosphorus. The cerium-doped metal organic framework material is a metal organic framework material prepared by taking zirconium as a metal center, 4,4-biphenyldicarboxylic acid as an organic ligand and doping cerium. The application method of the cerium-doped metal organic framework material for deeply removing organic phosphorus in waste water comprises the following steps: adjusting the pH of water containing organic phosphorus, and passing the water through an adsorption column filled with the metal organic framework material; when the adsorption is deactivated, soaking the filled material in lye, then washing the filled material with ultrapure water until the filled material is neutral, then washing and soaking the filled material with acid liquid to activate and regenerate the filled material, and low-temperature drying the filled material after the ultrapure water is washed until the filled material is neutral. The cerium-doped metal organic framework material for removing organic phosphorus is used to treat organic phosphorus, the pH of the water is 6.0+ / -0.1, and under the condition of coexisting high-concentration Cl ‑ , NO3 ‑ , SO4 2‑ , citric acid and other competitive substances, the content of organic phosphorus in the effluent can be reduced from 15 mg / L to below 0.1 mg / L (calculated in terms of P).

Description

Technical Field

[0001] The present invention belongs to the technical field of phosphorus-polluted water restoration, and in particular relates to a preparation method and application of a cerium-doped metal-organic framework material for removing organic phosphorus. Background Art

[0002] Phosphorus is an essential element for all organisms; however, excessive phosphorus discharge leads to eutrophication and damages aquatic ecosystems. In wastewater, phosphorus exists in two forms: inorganic phosphorus and organic phosphine. Common removal methods for these phosphorus species in wastewater treatment plants (WWTPs) include biological and chemical precipitation methods, but these methods are primarily effective for inorganic phosphorus and less effective for organic phosphorus. For example, in the effluent of a Boston WWTP that uses both biological and chemical phosphorus removal processes, dissolved organic phosphine (DOP) accounts for 26–81% of total dissolved phosphorus (TDP). Furthermore, Liu et al. studied the removal of different phosphorus components by different WWTP treatment processes. The results showed that biological treatment had a relatively low removal rate for DOP, while chemical precipitation removal removed virtually no DOP. Furthermore, the proportion of organic phosphine in total phosphorus gradually increased during the water treatment process. Therefore, the presence of organic phosphine often limits the efficiency of total phosphorus removal. To achieve lower total phosphorus discharge concentrations, attention must be paid to its removal.

[0003] Organophosphonic acids, a type of organic phosphine, are widely used in industries such as electroplating, textiles, and building materials due to their excellent stability and threshold efficiency. The six most widely used organophosphonic acids are 2-phosphonobutane-1,2,4-tricarboxylic acid (PBTC), hydroxy-1,1-ethylenediphosphonic acid (HEDP), aminotrimethylenephosphonic acid (NTMP), ethylenediaminetetramethylenephosphonic acid (EDTMP), hexamethylenediaminetetramethylenephosphonic acid (HDTMP), and diethylenetriaminepentamethylenephosphonic acid (DTPMP). Under natural conditions, organophosphonic acids released into the environment degrade into bioavailable orthophosphates, indirectly causing eutrophication. To date, various methods have been developed to remove organophosphonic acids from wastewater, including biodegradation, flocculation and precipitation, and adsorption. Adsorption, due to its low cost, high degradation efficiency, and strong regeneration capacity, has become the most practical strategy for degrading organophosphonic acids. Traditional adsorption materials include activated alumina, powdered zeolite, bauxite residues, modified biomass, and ion exchangers. However, it is difficult for these adsorption materials to achieve the ideal level of adsorption of organic phosphonic acid, and the energy absorption performance is easily interfered by the coexisting matrix, resulting in poor selective adsorption efficiency of organic phosphonic acid, which makes it difficult to meet the problem of efficient and selective removal of organic phosphonic acid in increasingly complex water bodies.

[0004] Metal-organic frameworks (MOFs) are a class of porous crystalline materials with periodic, multidimensional networks formed by the self-assembly of metal ions or metal clusters with organic ligands. Their highly developed pore structure and ultra-high surface area provide abundant chemically active sites, enabling efficient binding of toxic and hazardous pollutants in water. Among them, UiO-based MOFs are based on zirconium (Zr) as the metal center and terephthalic acid (H2BDC) as the organic ligand. Their unique Zr metal clusters exhibit exceptional affinity for phosphate. Due to their large pore size, high water stability, and unique Zr-OH groups, they are widely used in the adsorption and removal of organophosphines in wastewater. For example, Zhu et al. prepared UiO-66 for the efficient removal of sodium alendronate from water; Zhu et al. successfully prepared UiO-67 for the adsorption and removal of glyphosate and glufosinate ammonium from water. However, the relatively low adsorption capacity hinders the practical application of this type of MOFs materials in real water bodies. Therefore, it is of great significance to develop new adsorption materials with high adsorption capacity.

[0005] Rare earth elements (REEs), such as lanthanum (La) and cerium (Ce), exhibit excellent affinity for phosphate due to their naturally high coordination numbers (pKsp(LaPO4) = 26.15; pKsp(CePO4) = 25). Therefore, doping REEs with adsorbent materials has become a key strategy for developing highly efficient composite materials for phosphorus removal. Min et al. successfully doped La into UiO-66, reducing the coordination number of La-MOFs and resulting in higher phosphate adsorption. Cerium, the most abundant and readily available REE, has also been found to possess strong adsorption capacity for phosphate and other anionic pollutants. For example, Wang et al. synthesized a cerium-based composite adsorbent (Ce-Zr-Al composite adsorbent) with a maximum phosphate adsorption capacity of 73.51 mg / g. Li et al. also synthesized a novel, highly efficient adsorbent (HCO-SiO2) by loading hydrous cerium oxide nanoparticles onto porous silica microspheres and systematically investigated the phosphate adsorption properties of this material. Studies have shown that the adsorption capacity of HCO-SiO2 for phosphate is 85.5 mg / g. Unfortunately, most of the current research focuses on the adsorption performance of rare earth-based composite adsorption materials for phosphate, and very few studies involve organic phosphonic acid. The main challenges are: 1) the presence of organic phosphorus in wastewater is low, and it is difficult to achieve deep removal; 2) the impact of high-concentration coexisting matrices on the efficiency of functionalized MOFs in adsorbing organic phosphorus is not clearly understood. Ethylenediaminetetramethylenephosphonic acid (EDTMP) is a representative of organic phosphonic acid, and there are currently no articles or patents on the use of metal-organic framework materials for its removal. This patent successfully doped metal-organic framework materials with metals and innovatively used them to remove ethylenediaminetetramethylenephosphonic acid from water bodies. In addition, the process of the present invention also has the advantages of low equipment installation and maintenance costs. The material of the present invention only needs to be added to a stirring tank and a feeder with a water inlet and outlet to smoothly treat the water body. Since no equipment installation is required, the maintenance cost is low. Summary of the Invention

[0006] In view of the current application status of metal-organic framework materials in phosphorus pollution control, the purpose of the present invention is to provide a cerium-doped metal-organic framework material for removing organic phosphorus, a preparation method thereof, and its application in removing organic phosphorus from wastewater. It further discloses a method for using a cerium-doped metal-organic framework material to adsorb and remove organic phosphorus from wastewater, so as to solve the problems existing in the technology for treating organic phosphorus-contaminated water.

[0007] The method for preparing a cerium-doped metal-organic framework material for removing organic phosphorus is a metal-organic framework material prepared by using zirconium as the metal center, 4,4-biphenyldicarboxylic acid as the organic ligand, and doping with metallic cerium. The preparation method comprises the following steps:

[0008] 1) Dissolve zirconium salt and 4,4-diphenyldicarboxylic acid in a molar ratio of 1:0.5-1.5, and cerium salt and zirconium salt in a molar ratio of 0.25-1:1 in an organic solvent, ultrasonicate until completely dissolved, place in a sealed reactor, and then transfer the reactor to an oven at 100-150° C. for reaction for 20-30 hours;

[0009] 2) After the reaction in step 1) is completed, the reaction solution is centrifuged and filtered to obtain a solid product, which is then washed and dried to obtain the cerium-doped metal-organic framework material with the organophosphorus removed.

[0010] The method for preparing a cerium-doped metal-organic framework material for removing organic phosphorus is characterized in that in step 1), the molar ratio of zirconium salt to 4,4-biphenyldicarboxylic acid is 1:0.8-1.25, preferably 1:1; the molar ratio of zirconium salt to cerium salt is 1:0.6-0.8, preferably 1:0.7-0.75; and the total dispersed concentration of the zirconium salt and cerium salt in the organic solvent is 0.1-0.3 mmol / mL, preferably 0.15-0.2 mmol / mL.

[0011] The method for preparing a cerium-doped metal-organic framework material for removing organic phosphorus is characterized in that in step 1), the zirconium salt is zirconium chloride, the cerium salt is cerium chloride, and the organic solvent is DMF.

[0012] The cerium-doped metal-organic framework material for removing organic phosphorus provided by the present invention can be well applied to deeply remove organic phosphorus in wastewater, and the application method comprises the following steps:

[0013] S1: Adjust the pH of the water containing organic phosphorus to 2.0-10.0 (preferably 6.0±0.1);

[0014] S2: loading the cerium-doped metal organic framework material for removing organic phosphorus into an adsorption column, and then passing the organic phosphorus-containing water after pH adjustment in step S1 into the adsorption column;

[0015] S3: After the adsorption inactivation in step S2, regeneration treatment is performed. The metal organic framework material in the adsorption column is removed, soaked in alkaline solution, then rinsed with ultrapure water until neutral, and then soaked in acid solution for activation and regeneration. Finally, it is rinsed with ultrapure water until neutral and dried. The activation and regeneration are completed, and then it is repeated in step S2.

[0016] Furthermore, the organophosphorus in step S1 is ethylenediaminetetramethylenephosphonic acid (EDTMP).

[0017] Furthermore, in step S3, the alkaline solution is a 5-20 mmol / L sodium hydroxide solution, and the rinsing and soaking time is 20-40 minutes; the acid solution is a 5-20 mmol / L hydrochloric acid solution, and the rinsing and soaking time is 20-40 minutes.

[0018] Furthermore, the concentration of organic phosphorus in the water is less than 20 mg / L, preferably less than 15 mg / L, as measured by phosphorus. The flow rate of the organic phosphorus-containing water through the cerium-doped metal-organic framework material bed in the adsorption column for removing organic phosphorus is 0.5 to 2 BV / h, preferably 1 BV / h. When the effluent phosphorus concentration exceeds 0.01 mg / L, it is considered to have reached the leakage point and regeneration treatment is performed.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] (1) Metal-organic frameworks have low production costs and are widely available;

[0021] (2) Metal-organic framework materials have a large specific surface area and high adsorption capacity, and their removal rate for high-content organic phosphorus in water is very high, reaching over 80%, greatly improving the efficiency of the entire device;

[0022] (3) The metal cerium in the material of the present invention occupies the position of the metal zirconium in the matrix material, greatly increasing the active sites for adsorption of organic phosphonic acid. The cerium-doped metal-organic framework material of the present invention that removes organic phosphorus has a particularly good adsorption effect on ethylenediaminetetramethylenephosphonic acid (EDTMP). The high affinity of the metal cerium to form an inner sphere complex with the phosphonic acid group in EDTMP significantly increases the adsorption capacity of the metal-organic framework material for EDTMP.

[0023] (4) The material of the present invention only needs to be added to a stirring tank and a feeder with a water inlet and a water outlet to smoothly treat the water body. Since no equipment installation is required, the maintenance cost is low;

[0024] (5) The materials used in the method of the present invention do not have the phenomenon of phosphorus decomposition, and no metal zirconium and metal cerium are dissolved, thus avoiding secondary treatment and secondary pollution, and having good economic and social benefits. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The comparison chart of the adsorption effect of UiO-67 and Ce-UiO-67 on EDTMP at different times is shown in the figure.

[0026] Figure 2 The comparison chart of the adsorption effect of UiO-67 and Ce-UiO-67 on EDTMP at different pH values ​​is shown in the figure.

[0027] Figure 3 This is the dissolution diagram of zirconium ions and cerium ions of Ce-UiO-67 at pH = 6. DETAILED DESCRIPTION

[0028] The present invention will be further described below with reference to specific embodiments, but the protection scope of the present invention is not limited thereto.

[0029] First of all, it should be noted that UiO-67 refers to a metal-organic framework material with Zr as the metal center and 4,4-biphenyldicarboxylic acid as the organic ligand, and Ce-UiO-67 refers to UiO-67 doped with metallic cerium.

[0030] Blank example 1:

[0031] A cerium-doped metal-organic framework material for removing organic phosphorus, the specific preparation method is as follows:

[0032] 1) 3 mmol of zirconium chloride, 2.25 mmol of cerium chloride, and 3 mmol of 4,4-biphenyldicarboxylic acid were mixed and dissolved in 31 mL of DMF. After sonication until completely dissolved, the mixture was placed in a sealed reactor and placed in an oven at 120°C for 24 hours.

[0033] 2) The suspension after the reaction was placed in a centrifuge for centrifugal filtration to obtain a product, which was washed alternately with DMF and methanol three times, collected by centrifugation after washing, and placed in a vacuum drying oven under vacuum at 80° C. to obtain the material, which was labeled as Ce-UiO-67; wherein the centrifugal speed of the centrifuge was 7000-10000 rpm and the centrifugation time was 3-5 min.

[0034] The metal organic framework materials involved in the following Examples 1-22 are all cerium-doped metal organic framework materials prepared in Blank Example 1 with organic phosphorus removed.

[0035] Blank example 2:

[0036] A method for preparing a metal organic framework material. The preparation steps are repeated in Blank Example 1, except that cerium chloride is not added. The final material is labeled UiO-67.

[0037] Example 1

[0038] A method for removing common organic phosphorus in water using a cerium-doped metal-organic framework material for removing organic phosphorus, the specific steps of which are as follows:

[0039] 1) An organophosphorus solution containing ethylenediaminetetramethylenephosphonic acid (EDTMP) was adjusted to pH 6.0 ± 0.1. The concentration of the organophosphoric acid aqueous solution was 15 mg / L (as phosphorus) and the solution volume was 100 mL. 0.03 g of Ce-UiO-67 was added to the organophosphoric acid aqueous solution and the mixture was shaken in a constant temperature shaker at 25°C.

[0040] 2) Syringe-sampled solutions at time points of 5 min, 10 min, 0.5 h, 1 h, 1.5 h, 2 h, 4 h, 6 h, 9 h, 12 h, 18 h, 24 h, and 48 h were filtered through a 0.45 μm filter and the P concentration in the solutions was measured. The experimental results showed that the removal efficiency of organic phosphorus in the solutions was greater than 95% (calculated as P) 18 h after the reaction, and no desorption occurred thereafter.

[0041] 3) The metal organic framework material after adsorption of the organic phosphoric acid aqueous solution was separated from the solution by solid-liquid separation, and the filtrate was tested for the dissolution of zirconium ions and cerium ions. The results were as follows: Figure 3 The separated solid material was rinsed and soaked in 0.01 mol / L NaOH solution for 30 minutes, then rinsed with ultrapure water until neutral, and then rinsed and soaked in 0.01 mol / L HCl solution for 30 minutes for activation and regeneration. The regenerated metal-organic framework material was washed with ultrapure water until no organophosphorus appeared in the solution and the pH of the solution was near neutral. After solid-liquid separation, the composite material was vacuum-dried at room temperature.

[0042] 4) Repeating steps (1) and (2) with the regenerated metal organic framework material, the experimental results show that the removal rate of organic phosphorus in the solution is greater than 90% (in terms of P) 18 hours after the reaction.

[0043] According to the operation process of Example 1, the adsorption effect of Ce-UiO-67 on organic phosphoric acid at different times is summarized in Figure 1 It can be seen that the adsorption effect of Ce-UiO-67 on organic phosphoric acid reaches a stable state in about 10 hours.

[0044] Example 1-1

[0045] The operation process of Example 1 was repeated, except that Ce-UiO-67 was replaced by UiO-67 of equal mass. The final experimental results were as follows: The adsorption effect of UiO-67 on organic phosphoric acid at different times is summarized in Figure 1 It can be seen that the adsorption effect of UiO-67 on the six organophosphates reaches a stable state in about 12 hours.

[0046] Example 2

[0047] The same method as in Example 1 was used to treat organic phosphorus in water, except that a final concentration of 10 mmol / L sodium chloride was added to the aqueous solution of organic phosphorus. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% after 18 hours of reaction.

[0048] Example 3

[0049] The same method as in Example 1 was used to treat organic phosphorus in water, except that a final concentration of 10 mmol / L sodium nitrate was added to the aqueous solution of organic phosphorus. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% after 18 hours of reaction.

[0050] Example 4

[0051] The same method as in Example 1 was used to treat organic phosphorus in water, except that a final concentration of 10 mmol / L sodium sulfate was added to the aqueous solution of organic phosphoric acid. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% after 18 hours of reaction.

[0052] Example 5

[0053] The same method as in Example 1 was used to treat organic phosphorus in water, except that a final concentration of 10 mmol / L of sodium carbonate was added to the aqueous solution of organic phosphorus. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% after 18 hours of reaction.

[0054] Example 6

[0055] The same method as in Example 1 was used to treat organic phosphorus in water, except that humic acid was added to the aqueous solution of organic phosphoric acid at a final concentration of 10 mg / L. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0056] Example 7

[0057] The same method as in Example 1 was used to treat organic phosphorus in water, except that a final concentration of 10 mmol / L sodium chloride, 10 mmol / L sodium nitrate, 10 mmol / L sodium sulfate, 10 mmol / L sodium carbonate, and 10 mg / L humic acid was added to the aqueous solution of organic phosphorus. The experimental results showed that the organic phosphorus removal rate in the solution was greater than 90% 18 hours after the reaction.

[0058] Example 8

[0059] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 2.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0060] Example 9

[0061] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 3.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% after 18 hours of reaction.

[0062] Example 10

[0063] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 4.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0064] Example 11

[0065] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 5.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0066] Example 12

[0067] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 7.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0068] Example 13

[0069] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 8.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0070] Example 14

[0071] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 9.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0072] Example 15

[0073] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 10.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 95% 18 hours after the reaction.

[0074] Example 16

[0075] The same method as in Example 1 was used to treat organic phosphorus in water, except that the pH of the organic phosphoric acid aqueous solution was adjusted to 11.0±0.1. The experimental results showed that the removal rate of organic phosphorus in the solution was greater than 80% 18 hours after the reaction.

[0076] The adsorption effects of Ce-UiO-67 and Ce-UiO on organophosphates at different pH values ​​are summarized in Figure 2 .

[0077] Example 17

[0078] The same method as in Example 1 was used to treat organic phosphorus in water, except that ethylenediaminetetramethylenephosphonic acid (EDTMP) was replaced with 2-phospho-1,2,4-tricarboxylic acid butane (PBTC), hydroxyethylidene diphosphonic acid (HEDP), aminotrimethylphosphonic acid (NTMP), 1,6-hexanediaminetetramethylenephosphonic acid (HDTMP), or diethylenetriaminepentamethylphosphonic acid (DTPMP) at the same mass concentration, and the pH of the aqueous organic phosphoric acid solution was adjusted to 6.0±0.1. Other experimental conditions remained unchanged. The experimental results showed that the removal rates of organic phosphorus in the solution 18 hours after the reaction were greater than 25%, greater than 70%, greater than 75%, greater than 75%, and greater than 75%, respectively.

[0079] By comparing the experimental results of Example 17 and Example 1, it can be seen that the cerium-doped metal organic framework material for removing organic phosphorus of the present invention has very different adsorption effects on different types of organic phosphorus. It has a particularly excellent adsorption treatment effect on ethylenediaminetetramethylenephosphonic acid (EDTMP), while the treatment effect on other types of organic phosphorus is average.

[0080] Example 18

[0081] A method for removing common organic phosphorus in water using a cerium-doped metal-organic framework material for removing organic phosphorus, the specific steps of which are as follows:

[0082] 1) adjusting the pH of an aqueous solution containing ethylenediaminetetramethylenephosphonic acid (EDTMP) to 6.0±0.1, and the concentration of the organic phosphoric acid aqueous solution to 1 mg / L (in terms of phosphorus);

[0083] 2) The metal-organic framework material and quartz sand were mixed in a mass ratio of 6:1 (2 g of quartz sand) and evenly loaded into a jacketed glass adsorption column (Φ32 × 360 mm). 2 μm microporous membranes were placed at the top and bottom of the column to prevent adsorbent loss.

[0084] 3) The organophosphoric acid aqueous solution was treated according to the following steps: The organic phosphorus-containing water was pumped into a glass adsorption column filled with filler at a flow rate of 1 BV / h using suitable piping and a vacuum pump at 25°C ± 5°C. The experimental results showed that the organic phosphorus removal rate in the outlet water after treatment with the organophosphoric acid aqueous solution was greater than 99%, and the treatment capacity of the organophosphorus treatment group reaching the leakage point was approximately 530 BV or more.

[0085] 4) When the leakage point is reached (the P concentration in the effluent is greater than 0.01 mg / L), the operation is stopped, and the adsorption column filled with the metal organic framework material and the quartz sand adsorption material is disassembled, rinsed and soaked with a 0.01 mol / L NaOH solution for 30 minutes, then rinsed with ultrapure water until neutral, and then rinsed and soaked with a 0.01 mol / L HCl solution for 30 minutes for activation and regeneration, and finally rinsed with ultrapure water until neutral, and dried at 50°C. The regeneration rate of the metal organic framework material is greater than 95% (that is, when the regenerated metal organic framework material repeats steps (1)-(2)-(3) for treatment, the treatment capacity reaches more than 500 BV at the leakage point).

[0086] Example 19

[0087] The same method as in Example 17 was used to treat the organic phosphorus in the water body, except that in step 1), sodium chloride was added to the organic phosphoric acid aqueous solution at a final concentration of 10 mmol / L. The experimental results showed that the treatment volume reaching the leakage point in the organic phosphorus treatment group was approximately 480 BV or more.

[0088] Example 20

[0089] The same method as in Example 17 was used to treat organic phosphorus in water, except that in step 1), sodium nitrate was added to the organic phosphoric acid aqueous solution at a final concentration of 10 mmol / L. The experimental results showed that the treatment volume reaching the leakage point in the organic phosphorus treatment group was approximately 480 BV or more.

[0090] Example 21

[0091] The same method as in Example 17 was used to treat organic phosphorus in water, except that in step 1), sodium sulfate was added to the organic phosphoric acid aqueous solution at a final concentration of 10 mmol / L. The experimental results showed that the treatment volume reaching the leakage point in the organic phosphorus treatment group was approximately 480 BV or more.

[0092] Example 22

[0093] The same method as in Example 17 was used to treat organic phosphorus in water, except that in step 1), sodium carbonate was added to the organic phosphoric acid aqueous solution at a final concentration of 10 mmol / L. The experimental results showed that the treatment volume reaching the leakage point in the organic phosphorus treatment group was approximately 475 BV or more.

[0094] Example 23

[0095] The same method as in Example 17 was used to treat organic phosphorus in water, except that in step 1), humic acid was added to the aqueous solution of organic phosphoric acid to a final concentration of 10 mg / L. The experimental results showed that the treatment volume of the organic phosphorus treatment group reaching the leakage point was approximately 490 BV or more.

[0096] Example 24

[0097] The same method as in Example 17 was used to treat organic phosphorus in water, except that in step 1), the aqueous solution of organic phosphorus was supplemented with a final concentration of 10 mmol / L sodium chloride, 10 mmol / L sodium nitrate, 10 mmol / L sodium sulfate, 10 mmol / L sodium carbonate, and 10 mg / L humic acid. The experimental results showed that the treatment capacity of the organic phosphorus treatment group, reaching the leakage point, was approximately 450 BV or more.

[0098] The contents described in this specification are merely an enumeration of implementation forms of the inventive concept, and the protection scope of the present invention should not be considered as being limited to the specific forms described in the embodiments.

Claims

1. Application of a cerium-doped metal organic framework material for removing organic phosphorus in deep removal of organic phosphorus from wastewater, characterized in that The organophosphorus is ethylenediaminetetramethylenephosphonic acid (EDTMP), and the cerium-doped metal-organic framework material for removing the organophosphorus is a metal-organic framework material prepared by using zirconium as the metal center, 4,4-diphenyldicarboxylic acid as the organic ligand, and doping with metallic cerium. The preparation method thereof comprises the following steps: 1) Dissolve zirconium salt and 4, 4-diphenyldicarboxylic acid in an organic solvent at a molar ratio of 1:0.8-1.25 and a molar ratio of zirconium salt and cerium salt at a molar ratio of 1:0.6-0.

8. Ultrasonicate until completely dissolved and place in a sealed reactor. The reactor is then transferred to an oven and reacted at 100-150°C for 20-30 hours. 2) After the reaction in step 1) is completed, the reaction solution is centrifuged, filtered, washed, and dried to obtain the cerium-doped metal-organic framework material with the organophosphorus removed.

2. The use according to claim 1, characterized in that In step 1), the molar ratio of the zirconium salt to 4, 4-biphenyldicarboxylic acid is 1:1; the molar ratio of the zirconium salt to the cerium salt is 1:0.7-0.75; and the total dispersion concentration of the zirconium salt and the cerium salt in the organic solvent is 0.1-0.3 mmol / mL.

3. The use according to claim 2, characterized in that In step 1), the total dispersion concentration of the zirconium salt and the cerium salt in the organic solvent is 0.15-0.2 mmol / mL.

4. The use according to claim 1, characterized in that In step 1), the zirconium salt is zirconium chloride ZrCl4, the cerium salt is cerium chloride CeCl3, and the organic solvent is N,N-dimethylformamide DMF.

5. The use according to claim 1, characterized in that The application method includes the following steps: S1: Adjust the pH of water containing organic phosphorus to 2.0-10.0; S2: loading the cerium-doped metal organic framework material for removing organic phosphorus into an adsorption column, and then passing the organic phosphorus-containing water after pH adjustment in step S1 into the adsorption column; S3: After the adsorption inactivation in step S2, regeneration treatment is performed. The metal organic framework material in the adsorption column is removed, soaked in alkaline solution, then rinsed with ultrapure water until neutral, and then soaked in acid solution for activation and regeneration. Finally, it is rinsed with ultrapure water until neutral and dried. The activation and regeneration are completed, and then it is repeated in step S2.

6. The use according to claim 5, characterized in that In step S3, the alkaline solution is a 5-20 mmol / L sodium hydroxide solution, and the rinsing and soaking time is 20-40 min; the acid solution is a 5-20 mmol / L hydrochloric acid solution, and the rinsing and soaking time is 20-40 min.

7. The use according to claim 5, characterized in that The concentration of organic phosphorus in water is below 20 mg / L in terms of P, and the flow rate of the organic phosphorus-containing water passing through the cerium-doped-metal organic framework material bed in the adsorption column for removing organic phosphorus is 0.5~2BV / h.

8. The use according to claim 7, characterized in that The concentration of organic phosphorus-containing water in terms of P is below 15 mg / mL, and the flow rate of the organic phosphorus-containing water passing through the cerium-doped-metal organic framework material bed in the adsorption column for removing organic phosphorus is 1 BV / h.

9. The use according to claim 5, characterized in that When the P concentration in the effluent is greater than 0.01 mg / L, it is considered to have reached the leakage point and regeneration treatment is performed.

Images