A method for degrading new pollutants based on amino-modified iron coordination polymer activated peracetic acid

Abstract

The invention relates to the technical field of water treatment, and discloses a method for degrading new pollutants by activating peracetic acid based on an amino-modified iron coordination polymer. The amino-modified iron coordination polymer used in the present invention has a large specific surface area and many voids, and can adsorb new pollutants. The surface of the amino-modified iron coordination polymer in the present invention has abundant electron transfer channels, and can continuously and efficiently activate peracetic acid to produce a large number of surface high-valent iron sites in water. At the same time, the amino-modified iron coordination polymer can adsorb new pollutants, and the generated high-valent iron can be quickly oxidized and degraded through double electron transfer, overcoming the disadvantage that the existing metal organic framework material activated persulfate or peracetic acid in the water treatment technology has an unsatisfactory effect on degrading organic pollutants; and in the degradation process, the generated high-valent iron has a good anti-interference ability to common ions and organic matter in actual sewage.

Description

Technical Field

[0001] The invention relates to the technical field of water treatment, and in particular to a method for degrading new pollutants based on amino-modified iron coordination polymer activated peracetic acid. Background Art

[0002] Emerging organic pollutants (NEPs) have been widely detected in surface water, groundwater and even drinking water sources in many regions around the world, attracting widespread attention from the public and the scientific community. The concentrations of new pollutants in the environment are usually low, but drinking water contaminated by such pollutants may cause a series of health problems, including endocrine system disruption, nervous system damage, reproductive system problems and increased risk of certain types of cancer. Therefore, it is crucial to develop efficient processes for removing emerging pollutants. Efficient removal of new pollutants in sewage treatment plants is a key link in reducing new pollutants in the water environment.

[0003] Peracetic acid is a green oxidant and disinfectant, and no disinfection by-products are generated during the water treatment process. Peracetic acid is easily activated by transition metals (such as iron, manganese, cobalt, copper, etc.) and their oxides to produce highly oxidizing active free radicals, thereby rapidly and efficiently degrading new pollutants. The advanced oxidation technology developed based on peracetic acid has been reported to have great advantages in removing new pollutants and has received widespread attention.

[0004] Wang Shixiang et al., Environmental Chemistry, 2022, No. 09, disclosed a method based on ferrous iron to activate peracetic acid to produce free radicals to degrade triclosan, a typical new pollutant. This method can quickly degrade new pollutants, but it requires the addition of excessive ferrous iron ions to achieve continuous activation of peracetic acid, which also causes a large consumption of oxidants. The reaction needs to be controlled in strict acidity to achieve a better removal effect; in addition, the product of ferrous iron activation is ferric iron, which is easy to form a large amount of iron sludge, which may seriously affect the treatment process of the water plant.

[0005] CN202310058630.3 discloses a method for removing organic pollutants by using peracetic acid in cooperation with divalent iron and hydroxylamine. The trivalent iron generated by the reduction of hydroxylamine is divalent iron, thereby realizing sustainable activation of peracetic acid, solving the problem that traditional divalent iron activation of peracetic acid requires consumption of a large amount of reagents and produces a large amount of iron mud. However, the added hydroxylamine is toxic, and the residual hydroxylamine discharge is also a pollutant to the water body.

[0006] In addition, transition metal-activated peracetic acid often removes pollutants through the free radicals it produces. However, due to their short lifespan and lack of selectivity, free radicals such as hydroxyl radicals (HO·) and organic radicals (RO·) are easily quenched by other substrates in the water in a complex sewage background, which seriously affects the effectiveness of free radicals in degrading emerging pollutants. The use of appropriate activation methods can produce active species with long lifespans and selective effects, which can effectively remove new pollutants and resist actual water quality interference. This is one of the strategies to replace free radical-dominated degradation of new pollutants.

[0007] Iron-based metal organic framework materials are a new type of catalytic material formed by metal clusters and organic ligands with high specific surface area, porous structure and multiple active sites. For example, typical iron-based metal organic framework materials synthesized by Materials of Institute Lavoisier (MIL): MIL-101 (Fe), MIL-100 (Fe), etc. have been proven to have certain catalytic effects on persulfate, hydrogen peroxide, peracetic acid, etc.

[0008] CN202011560106.9 discloses Fe-MOFs peracetic acid catalyst and preparation method and its application in organic pollutant degradation. However, this method prepares metal organic framework materials by calcination, and the reaction requires high temperature calcination, which consumes a lot of energy.

[0009] Classical iron-based metal organic framework materials are not very efficient in the treatment of pollutants, and the electron utilization rate is low during the activation process, making it difficult to achieve efficient removal of difficult-to-degrade organic pollutants in water. Therefore, constructing a peracetic acid system based on metal organic frameworks that can efficiently activate peracetic acid and resist the interference of complex water quality background is of great significance for the efficient removal of difficult-to-degrade emerging pollutants in water. Summary of the invention

[0010] The purpose of the present invention is to provide a method for degrading new pollutants based on amino-modified iron coordination polymers activating peracetic acid based on the above technical problems.

[0011] The technical solution of the present invention:

[0012] The first aspect of the present invention provides a method for degrading new pollutants based on amino-modified iron coordination polymer activated peracetic acid, the method comprising:

[0013] Adding peracetic acid solution to sewage containing new pollutants to obtain a sewage system with a pH value of 4 to 7; the concentration of the peracetic acid solution is 50 mmol / L;

[0014] The amino-modified iron coordination polymer is added to the sewage system and stirred to be completely mixed, and then placed on a magnetic stirrer to react at 300 rpm for 20 to 30 minutes, during which the concentration of new pollutants is measured.

[0015] The technical solution of the present invention has at least the following beneficial effects:

[0016] (1) The amino-modified iron coordination polymer used in the present invention has a large specific surface area and many voids, and can adsorb new pollutants. The surface of the amino-modified iron coordination polymer in the present invention has abundant electron transfer channels, which can continuously and efficiently activate peracetic acid to produce a large number of surface high-valent iron sites in water. At the same time, the amino-modified iron coordination polymer can adsorb new pollutants, and the generated high-valent iron can quickly oxidize and degrade new pollutants through double electron transfer, overcoming the shortcomings of the existing metal organic framework materials in the water treatment technology of activating persulfate or peracetic acid, and the degradation effect of organic pollutants is not ideal; and in the degradation process, the generated high-valent iron has good anti-interference ability to common ions and organic matter in actual sewage, such as sulfate ions, chloride ions, humic acid, etc.

[0017] (2) The method of the present invention can be used to efficiently degrade a variety of common new pollutants that are difficult to degrade in water, such as phenolic substances (such as bisphenol A), sulfonamide antibiotics (such as sulfamethoxazole, sulfadiazine, etc.), and drugs (such as naproxen).

[0018] (3) By adopting the method of the present invention, the separation of solid and liquid products after the degradation reaction is simple, and the amino-modified iron coordination polymer has a stable structure and can be recycled many times without releasing foreign ions into the aqueous phase. The iron dissolution amount is low and almost no dissolution occurs, thus avoiding secondary pollution.

[0019] (4) The method of the present invention uses peracetic acid to adjust the pH, and does not require the addition of additional acid or alkali, and has a wide range of applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a diagram showing the degradation effect of sulfamethoxazole pollutants in Example 1, Example 2, Example 3, Example 4, and Comparative Example 1 within 30 minutes;

[0021] Figure 2 It is a diagram showing the degradation effect of sulfamethoxazole pollutants in Example 1, Example 13, Example 14, Example 15, and Example 16 within 30 minutes;

[0022] Figure 3 It is a graph showing the degradation effects of benzoic acid and sulfamethoxazole pollutants in Example 1 and Example 17 within 30 minutes;

[0023] Figure 4It is the degradation of methyl phenyl sulfoxide (PMSO), the formation effect diagram of methyl phenyl sulfone (PMSO2) and the conversion rate of methyl phenyl sulfone in Example 1 and Example 18 within 30 minutes;

[0024] Figure 5 is a diagram showing the degradation effect of sulfamethoxazole pollutant in Example 5 of the present invention;

[0025] Figure 6 It is a comparison chart of the removal rates of sulfamethoxazole pollutants in Example 1, Example 6, Example 7, Example 8, and Example 9 after 30 minutes of reaction;

[0026] Figure 7 is a comparison chart of the removal rate of new pollutants in Example 12 after 30 minutes of reaction;

[0027] Figure 8 It is a comparison chart of the removal rates of sulfamethoxazole pollutants in Example 1, Example 10, and Example 11 after 30 minutes of reaction;

[0028] Fig. 9 is a SEM image of the amino-modified iron coordination polymer obtained by the present invention;

[0029] Fig.10 is the XRD diagram of the amino-modified iron coordination polymer obtained by the present invention;

[0030] Fig.11 The present invention is a nitrogen adsorption-desorption diagram of the amino-modified iron coordination polymer obtained by the present invention. DETAILED DESCRIPTION

[0031] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0032] As mentioned above, the first aspect of the present invention provides a method for degrading new pollutants based on amino-modified iron coordination polymer activated peracetic acid, the method comprising:

[0033] Adding peracetic acid solution to sewage containing new pollutants to obtain a sewage system with a pH value of 4 to 7; the concentration of the peracetic acid solution is 50 mmol / L;

[0034] The amino-modified iron coordination polymer is added to the sewage system and stirred to be completely mixed, and then placed on a magnetic stirrer to react at 300 rpm for 20 to 30 minutes, during which the concentration of new pollutants is measured.

[0035] According to a particularly preferred embodiment, the method for preparing the amino-modified iron coordination polymer comprises:

[0036] Adding ferric chloride hexahydrate and 2-aminoterephthalic acid to N,N-dimethylformamide, and ultrasonicating for 10 to 20 minutes to obtain a precursor solution;

[0037] The precursor solution is poured into a polytetrafluoroethylene liner and transferred to a hydrothermal reactor, reacted at 120-150° C. for 5-24 hours, cooled naturally along with the reactor, and then placed in a centrifuge for centrifugal separation at 5000-15000 rpm for 5-10 minutes, and the solid phase is taken, washed with dimethylacetamide and anhydrous ethanol in sequence, and then placed in a forced air drying oven for drying at 60-80° C. for 12-24 hours to obtain an amino-modified iron coordination polymer.

[0038] In the present invention, the amino-modified iron coordination polymer is an important technical feature. The surface of the amino-modified iron coordination polymer has abundant electron transfer channels, which can continuously and efficiently activate peracetic acid to produce a large number of surface high-valent iron sites in water. At the same time, the amino-modified iron coordination polymer can adsorb new pollutants, and the generated high-valent iron can quickly oxidize and degrade new pollutants through double electron transfer, overcoming the shortcomings of the existing metal organic framework materials in activating persulfate or peracetic acid in water treatment technology, and the degradation effect of organic pollutants is not ideal; and in the degradation process, the generated high-valent iron has good anti-interference ability to common ions and organic matter in actual sewage, such as sulfate ions, chloride ions, humic acid, etc.

[0039] Further preferably, the molar ratio of the hexahydrate ferric chloride to the 2-aminoterephthalic acid is 1: 2 to 2: 1. The inventors of the present invention have found that under this preferred condition, the yield of the amino-modified iron coordination polymer is higher, and if the molar ratio of the hexahydrate ferric chloride to the 2-aminoterephthalic acid is too large or too small, the yield of the amino-modified iron coordination polymer will not increase, but the consumption of raw materials will increase.

[0040] Preferably, the amount of N,N-dimethylformamide used is 10 to 1000 mL.

[0041] Preferably, the new pollutant is a sulfamethoxazole pollutant, sulfa, sulfamethoxazole, sulfadiazine, sulfadimethoxine, sulfachloropyridazine, sulfamethoxypyridazine, sulfathiazole, naproxen or bisphenol A.

[0042] Preferably, in 100 mL of sewage, the amount of the peracetic acid solution added is 0.2 to 1 mL relative to 10 μmol / L of new pollutants. The inventors of the present invention have found that under this preferred condition, the utilization rate of peracetic acid is higher, and if the amount of the peracetic acid solution added is too small, the activation effect is poor, and if the amount of the peracetic acid solution added is too large, the activation effect will not be significantly improved, but it will cause a waste of oxidant.

[0043] More preferably, in 100mL of sewage, relative to 10μmol / L of new pollutants, the amount of the amino-modified iron coordination polymer added is 5 to 20mg. The inventors of the present invention have found that under this preferred condition, the activation efficiency is higher; in 100mL of sewage, relative to 10μmol / L of new pollutants, the amount of the amino-modified iron coordination polymer added is too small, and the activation effect is poor; in 100mL of sewage, relative to 10μmol / L of new pollutants, the amount of the amino-modified iron coordination polymer added is too large, and the deactivation effect will not be significantly improved, but it will cause material waste.

[0044] The present invention will be described in detail below by way of examples. In the following examples, unless otherwise specified, the raw materials are all commercially available.

[0045] Example 1

[0046] This example is used to provide a method for degrading new pollutants by activating peracetic acid based on amino-modified iron coordination polymers. The method comprises: taking 99 mL of sewage I, testing it, and obtaining that the sewage I contains 10 μmol / L of sulfamethoxazole pollutants, adding a 50 mmol / L peracetic acid solution thereto, and measuring that the pH of the sewage system is 4; relative to the 10 μmol / L of sulfamethoxazole pollutants, the amount of the peracetic acid solution added is 1 mL;

[0047] An amino-modified iron coordination polymer is added to the sewage system and stirred to ensure complete mixing. The system is then placed on a magnetic stirrer and reacted at 300 rpm for 30 min. The concentration of the sulfamethoxazole pollutant is measured at the 2nd minute, the 4th minute, the 6th minute, the 8th minute, the 10th minute, the 15th minute, the 20th minute and the 30th minute respectively. Relative to 10 μmol / L of the sulfamethoxazole-containing pollutant, the amount of the amino-modified iron coordination polymer added is 10 mg.

[0048] Wherein, the preparation method of the amino-modified iron coordination polymer is as follows:

[0049] Weigh 0.81 g of ferric chloride hexahydrate and 0.41 g of 2-aminoterephthalic acid, add them into a beaker containing 30 mL of N,N-dimethylformamide, and sonicate for 10 min to obtain a precursor solution;

[0050] The precursor solution was poured into a 50 mL polytetrafluoroethylene liner and transferred to a hydrothermal reactor, reacted at 120° C. for 12 h, cooled naturally along with the reactor, and then placed in a centrifuge for centrifugal separation at 10,000 rpm for 5 min. The solid phase was taken, washed three times with dimethylacetamide and anhydrous ethanol in sequence, and then placed in a forced air drying oven and dried at 60° C. for 12 h to obtain a brown-yellow powder, i.e., an amino-modified iron coordination polymer.

[0051] Example 2

[0052] The method in Example 1 was followed, except that the amount of the amino-modified iron coordination polymer added was 5 mg relative to 10 μmol / L of the sulfamethoxazole-containing pollutant, and the remaining steps and parameters were the same as in Example 1.

[0053] Example 3

[0054] The method in Example 1 was followed, except that the amount of the amino-modified iron coordination polymer added was 15 mg relative to 10 μmol / L of sulfamethoxazole-containing pollutants, and the remaining steps and parameters were the same as in Example 1.

[0055] Example 4

[0056] The method in Example 1 was followed, except that the amount of the amino-modified iron coordination polymer added was 20 mg relative to 10 μmol / L of the sulfamethoxazole-containing pollutant, and the remaining steps and parameters were the same as in Example 1.

[0057] Example 5

[0058] This example is used to provide a method for degrading new pollutants by activating peracetic acid based on amino-modified iron coordination polymers. The method comprises: taking 99 mL of sewage I, testing it, and obtaining that the sewage I contains 10 μmol / L of sulfamethoxazole pollutants, adding a 50 mmol / L peracetic acid solution thereto, and measuring that the pH of the sewage system is 4; relative to the 10 μmol / L of sulfamethoxazole pollutants, the amount of the peracetic acid solution added is 1 mL;

[0059] Adding the amino-modified iron coordination polymer to the sewage system, stirring to make it completely mixed, and then placing it on a magnetic stirrer to react at 300 rpm for 30 minutes; relative to 10 μmol / L of sulfamethoxazole-containing pollutants, the amount of the amino-modified iron coordination polymer added is 10 mg;

[0060] After each reaction for 30 minutes, the sulfamethoxazole pollutant was replenished so that the concentration of the sulfamethoxazole pollutant was 10 μmol / L, and the sewage volume was controlled to 99 mL, and then 1 mL of a 50 mmol / L peracetic acid solution was added. The amino-modified iron coordination polymer was reused 4 times, and the concentration of the sulfamethoxazole pollutant was measured at the 2nd minute, 4th minute, 6th minute, 8th minute, 10th minute, 15th minute, 20th minute, and 30th minute, respectively.

[0061] Wherein, the preparation method of the amino-modified iron coordination polymer is the same as that in Example 1.

[0062] Example 6

[0063] The method in Example 1 was followed, except that the same volume of sewage II was used to replace the sewage I, the sewage II contained sodium chloride with a concentration of 10 mmol / L and sulfamethoxazole with a concentration of 10 μmol / L, and the remaining steps and parameters were the same as in Example 1.

[0064] Example 7

[0065] The method in Example 1 was followed, except that the same volume of sewage III was used to replace the sewage I, the sewage III contained sodium sulfate with a concentration of 10 mmol / L and sulfamethoxazole with a concentration of 10 μmol / L, and the remaining steps and parameters were the same as in Example 1.

[0066] Example 8

[0067] The method in Example 1 was followed, except that the same volume of sewage IV was used to replace the sewage I, the sewage IV contained a humic acid solution with a concentration of 5 mg / L and a sulfamethoxazole pollutant with a concentration of 10 μmol / L, and the remaining steps and parameters were the same as in Example 1.

[0068] Example 9

[0069] The method in Example 1 was followed, except that the sewage I was replaced by the same volume of sewage V, the sewage V contained a humic acid solution with a concentration of 3 mg / L and a sulfamethoxazole pollutant with a concentration of 10 μmol / L, and the remaining steps and parameters were the same as in Example 1.

[0070] Example 10

[0071] The method in Example 1 was followed, except that the same volume of sewage VI was used to replace the sewage I, and the sewage VI was actual sewage plant outlet water containing sulfamethoxazole pollutants at a concentration of 10 μmol / L. The remaining steps and parameters were the same as in Example 1.

[0072] Embodiment 11

[0073] The method in Example 1 was followed, except that the same volume of sewage VII was used to replace the sewage I, and the sewage VII was source reservoir water containing a sulfamethoxazole pollutant with a concentration of 10 μmol / L. The remaining steps and parameters were the same as in Example 1.

[0074] Example 12

[0075] The method in Example 1 is followed, except that the sewage 1 to sewage 9 of the same volume are used to replace the sewage I, and the remaining steps and parameters are the same as in Example 1.

[0076] Among them, the sample 1 contains sulfa at a concentration of 10 μmol / L, the sample 2 contains sulfamethoxazole at a concentration of 10 μmol / L, the sample 3 contains sulfadiazine at a concentration of 10 μmol / L, the sample 4 contains sulfadimethoxine at a concentration of 10 μmol / L, the sample 5 contains sulfachloropyridazine at a concentration of 10 μmol / L, the sample 6 contains sulfamethoxypyridazine at a concentration of 10 μmol / L, the sample 7 contains sulfathiazole at a concentration of 10 μmol / L, the sample 8 contains bisphenol A at a concentration of 10 μmol / L, and the sample 1 contains naproxen at a concentration of 10 μmol / L.

[0077] Example 13

[0078] The method in Example 1 was followed, except that 100 μL of 5 mol / L tert-butyl alcohol was added as a quencher before the amino-modified iron coordination polymer was added to initiate the reaction. The remaining steps and parameters were the same as in Example 1.

[0079] Embodiment 14

[0080] The method in Example 1 was followed, except that 100 μL of 5 mol / L 2,4-hexadiene was added as a quencher before the amino-modified iron coordination polymer was added to initiate the reaction. The remaining steps and parameters were the same as in Example 1.

[0081] Embodiment 15

[0082] The method in Example 1 was followed, except that 100 μL of 5 mol / L methanol was added as a quencher before the amino-modified iron coordination polymer was added to initiate the reaction. The remaining steps and parameters were the same as in Example 1.

[0083] Example 16

[0084] The method in Example 1 was followed, except that 100 μL of 5 mol / L methyl phenyl sulfoxide was added as a quencher before the amino-modified iron coordination polymer was added to initiate the reaction. The remaining steps and parameters were the same as in Example 1.

[0085] Embodiment 17

[0086] The method in Example 1 was followed, except that 100 μL of 10 mmol / L benzoic acid was added to the sewage I. The remaining steps and parameters were the same as in Example 1.

[0087] Embodiment 18

[0088] The method in Example 1 was followed, except that 100 μL of 100 mmol / L methyl phenyl sulfoxide was added to the sewage I, and the remaining steps and parameters were the same as in Example 1.

[0089] Comparative Example 1

[0090] The method in Example 1 was followed, except that the same amount of iron coordination polymer A was used to replace the amino-modified iron coordination polymer. The remaining steps and parameters were the same as in Example 1.

[0091] The preparation method of the iron coordination polymer A is as follows: 0.81 g of ferric chloride hexahydrate and 0.38 g of terephthalic acid are weighed and added into a beaker containing 30 mL of N,N-dimethylformamide, and ultrasonicated for 10 minutes to obtain a precursor solution;

[0092] The precursor solution was poured into a 50 mL polytetrafluoroethylene liner and transferred to a hydrothermal reactor, reacted at 120° C. for 12 h, cooled naturally along with the reactor, and then placed in a centrifuge for centrifugal separation at 10,000 rpm for 5 min. The solid phase was taken, washed with dimethylacetamide and anhydrous ethanol three times in sequence, and then placed in a forced air drying oven and dried at 60° C. for 12 h to obtain a brown-yellow powder, i.e., an iron coordination polymer A with terephthalic acid as an organic ligand.

[0093] Test Example 1

[0094] Summarize the degradation effects of sulfamethoxazole pollutants in the above examples 1, 2, 3, 4 and comparative example 1 within 30 minutes. The results are as follows: Figure 1 As shown. Figure 1 In the figure, the ordinate represents the ratio of the sulfamethoxazole pollutant concentration to the initial concentration at the corresponding reaction time.

[0095] Depend on Figure 1It is known that terephthalic acid modified iron coordination polymer is mixed with peracetic acid and hardly degrades sulfamethoxazole pollutants, while the amino-modified iron coordination polymer synthesized by 2-aminoterephthalic acid used in the embodiment of the present invention can quickly degrade sulfamethoxazole pollutants after mixing with peracetic acid. In addition, with the increase of the dosage of amino-modified iron coordination polymer, the rate of degradation of sulfamethoxazole pollutants becomes faster, and the degradation effect is also improved, such as: when the dosage of amino-modified iron coordination polymer is 5mg, after 30 minutes, the removal rate of sulfamethoxazole pollutants is 70%, when the dosage of amino-modified iron coordination polymer is ≥10mg, the removal rate of sulfamethoxazole pollutants is ≥90%, when the dosage of amino-modified iron coordination polymer is 20mg, after 30 minutes, the removal rate of sulfamethoxazole pollutants is 100%.

[0096] Test Example 2

[0097] Summarize the degradation effects of sulfamethoxazole pollutants in the above Examples 1, 13, 14, 15 and 16 within 30 minutes. The results are as follows: Figure 2 As shown. Figure 2 In the figure, the ordinate represents the ratio of the sulfamethoxazole pollutant concentration to the initial concentration at the corresponding reaction time.

[0098] Depend on Figure 2 It can be seen that the addition of tert-butyl alcohol has no significant effect on the degradation of sulfamethoxazole, indicating that no hydroxyl radicals are generated in the system. 2,4-hexadiene, methanol, and methyl phenyl sulfoxide significantly inhibit the degradation of sulfamethoxazole, indicating that high-valent iron and acetyl radicals may play an important role in the degradation of sulfamethoxazole in the system.

[0099] Test Example 3

[0100] Summarizing the degradation effects of pollutants in the above Examples 1 and 17 within 30 minutes, the results are as follows: Figure 3 As shown. Figure 3 In the figure, the ordinate represents the ratio of the concentration of sulfamethoxazole or benzoic acid to the initial concentration at the corresponding reaction time.

[0101] Depend on Figure 3 It can be seen that benzoic acid is not degraded in the amino-modified iron coordination polymer activated peracetic acid system, proving that no acetyl radicals are generated in the system.

[0102] Furthermore, by using methyl phenyl sulfoxide as a probe experiment for the generation of high-valent iron, it was explored whether methyl phenyl sulfoxide would be converted into methyl phenyl sulfone (PMSO2) in the amino-modified iron coordination polymer activated peracetic acid system. The degradation of methyl phenyl sulfoxide (PMSO), the generation effect diagram of methyl phenyl sulfone (PMSO2) and the conversion rate of methyl phenyl sulfone in Example 1 and Example 18 within 30 minutes were shown. Figure 4 As shown. Figure 4 It can be seen that methyl phenyl sulfoxide can be efficiently converted into methyl phenyl sulfone (PMSO2) in this system, and the conversion rate within 10 minutes is greater than 90%, which proves that high-valent iron will be rapidly generated in the system and play a major role in the degradation of sulfamethoxazole.

[0103] Test Example 4

[0104] The degradation effect of sulfamethoxazole pollutants in Example 5 is summarized, and the results are as follows: Figure 5 As shown. Figure 5 In the figure, the ordinate represents the ratio of the sulfamethoxazole pollutant concentration to the initial concentration at the corresponding reaction time.

[0105] Depend on Figure 5 It can be seen that after the amino-modified iron coordination polymer used in the embodiment of the present invention is recycled for 4 times, it still maintains a high removal rate of sulfamethoxazole pollutants (more than 85%), and no total iron ions are detected in the system. Among them, the fourth time, the removal rate of sulfamethoxazole pollutants was slightly reduced, which may be due to the fact that each time the sulfamethoxazole pollutants were sampled, 1mL of the sample was carried out with part of the coordination polymer, which reduced the amino-modified iron coordination polymer in the system.

[0106] In summary, the amino-modified iron coordination polymer used in the embodiment of the present invention has excellent reusability when activating peracetic acid to degrade sulfamethoxazole pollutants.

[0107] Test Example 5

[0108] Summarizing the degradation effects of sulfamethoxazole pollutants in the above Examples 1, 6, 7, 8, and 9 after 30 minutes of reaction, the results are as follows: Figure 6 As shown. Figure 6 In the figure, the ordinate represents the ratio of the sulfamethoxazole pollutant concentration to the initial concentration at the corresponding reaction time.

[0109] Depend on Figure 6 It can be seen that the effect of the amino-modified iron coordination polymer used in the embodiment of the present invention to activate peracetic acid to degrade sulfamethoxazole pollutants is not affected by sulfate ions, chloride ions, and humic acid, and still has a high degradation rate of sulfamethoxazole pollutants.

[0110] Test Example 6

[0111] After 30 minutes of reaction, the removal rate of new pollutants in Example 12 was summarized, and the results are as follows: Figure 7 shown.

[0112] Depend on Figure 7It can be seen that the amino-modified iron coordination polymer activated peracetic acid used in the embodiment of the present invention can degrade a variety of new pollutants, and the removal rate of these new pollutants has reached more than 80%.

[0113] Test Example 7

[0114] Summarizing the removal rates of sulfamethoxazole pollutants in the above Examples 1, 10, and 11 after 30 minutes of reaction, the results are as follows: Figure 8 shown.

[0115] Depend on Figure 8 It can be seen that the amino-modified iron coordination polymer activated peracetic acid of the present invention exhibits good degradation effects on both source reservoir water and actual sewage treatment plant discharge water, indicating that the application of the amino-modified iron coordination polymer activated peracetic acid of the present invention in actual water bodies has broad prospects.

[0116] In order to more clearly express the method for degrading new pollutants based on amino-modified iron coordination polymer activated peracetic acid, the present invention is as follows: Fig. 9 The SEM image of the amino-modified iron coordination polymer is shown. Fig.10 shows the XRD pattern of the amino-modified iron coordination polymer, Fig.11 A nitrogen adsorption-desorption diagram of an amino-modified iron coordination polymer is shown.

[0117] Depend on Fig. 9 It can be seen that the amino-modified iron coordination polymer obtained in the present invention has an octahedral structure; Fig.10 It can be seen that the amino-modified iron coordination polymer obtained in the present invention is a crystalline iron-benzenecarboxylic acid coordination polymer material; Fig.11 It can be seen that the specific surface area of ​​the amino-modified iron coordination polymer obtained in the present invention is 984.33 m 2 g -1 , which can promote the adsorption of peracetic acid and new pollutants in the degradation system, and promote the activation of peracetic acid to produce strong oxidizing species.

[0118] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A method for degrading new pollutants based on amino-modified iron coordination polymer activated peracetic acid, characterized in that: The method includes: Adding peracetic acid solution to sewage containing new pollutants to obtain a sewage system with a pH value of 4 to 7; the concentration of the peracetic acid solution is 50 mmol / L; The new pollutant is sulfonamide, sulfamethoxazole, sulfadiazine, sulfadimethazine, sulfachloropyridazine, sulfamethoxypyridazine, sulfathiazole, naproxen or bisphenol A; Adding the amino-modified iron coordination polymer to the sewage system, stirring to make it completely mixed, and then placing it on a magnetic stirrer to react at 300 rpm for 20 to 30 minutes, during which the concentration of the new pollutant is measured; The preparation method of the amino-modified iron coordination polymer comprises: Add ferric chloride hexahydrate and 2-aminoterephthalic acid to N,N-dimethylformamide, and perform ultrasonic treatment for 10-20 minutes to obtain a precursor solution; The precursor solution is poured into a polytetrafluoroethylene liner and transferred to a hydrothermal reactor, reacted at 120-150° C. for 5-24 hours, cooled naturally along with the reactor, and then placed in a centrifuge for centrifugal separation at 5000-15000 rpm for 5-10 minutes, and the solid phase is taken, washed with dimethylacetamide and anhydrous ethanol in sequence, and then placed in a forced air drying oven and dried at 60-80° C. for 12-24 hours to obtain an amino-modified iron coordination polymer.

2. The method according to claim 1, characterized in that in, The molar ratio of the ferric chloride hexahydrate to the 2-aminoterephthalic acid is 1:2 to 2:

1.

3. The method according to claim 1, characterized in that in, The amount of N,N-dimethylformamide used is 10-1000 mL.

4. The method according to claim 1 or 2, characterized in that: in, In 100 mL of sewage, relative to 10 μmol / L of new pollutants, the amount of peracetic acid solution added is 0.2-1 mL.

5. The method according to claim 1 or 2, characterized in that: in, In 100 mL of sewage, the amount of the amino-modified iron coordination polymer added is 5-20 mg relative to 10 μmol / L of new pollutants.

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