A gel type composite nanomaterial for perfluoro and polyfluoro alkyl substance removal and a method of application thereof

Abstract

The application discloses a gel type composite nanometer material for removing perfluorinated and polyfluorinated alkyl substances and an application method thereof, and the gel type composite nanometer material is composed of gel type strong alkaline anion resin with a functional group of quaternary ammonium and zirconium / iron / manganese nanometer material. 3 The gel type composite nanometer material has a pore volume of 0.001-0.01 cm / g and an absolute swelling rate of 1.05-1.25, and therefore can have a good adsorption effect under different pH and coexisting ion conditions; and the gel type composite nanometer material can be recycled through desorption regeneration, and the regeneration bed volume change rate and the desorption swelling rate are stable, the desorption time is 6-8 hours, the gel type composite nanometer material volume change rate is 0.9-1.1, and the desorption swelling rate is 0.9-1.05.

Description

TECHNICAL FIELD

[0001] The present application belongs to the field of adsorption materials, and particularly relates to a gel-type composite nanomaterial for removing perfluoro and polyfluoro alkyl substances and an application method thereof. BACKGROUND

[0002] Perfluorinated compounds are a new type of persistent organic pollutants, which are generally composed of a perfluorinated hydrophobic alkyl carbon chain and a hydrophilic functional group. In recent years, they have attracted much attention in the environmental field. Perfluorinated compounds are widely used in chemical industry, electroplating, textiles, leather, synthetic detergents, coatings, fire-fighting facilities, etc. Perfluorinated compounds have been detected worldwide, and water pollution by perfluorinated compounds is widespread. When the accumulation of perfluorinated compounds in animals and humans reaches a certain concentration threshold, it can produce carcinogenic, neurotoxic, organ toxicity, immune and endocrine toxicity, reproductive toxicity, etc., and pose a threat to human health. In recent years, the control standards for perfluorinated compounds have become increasingly stringent. Since 2022, China has set the drinking water health standards for perfluoroctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS) at 80 ng / L and 40 ng / L, respectively. Therefore, the control of perfluorinated compounds in water environment is particularly important.

[0003] Adsorption method has great potential in the treatment of perfluorinated compound pollution due to its simple operation, low cost, safety and harmlessness, etc. Common perfluorinated compound adsorption materials include activated carbon, ion exchange resin, mineral material, nanomaterial, etc. Among them, gel-type ion exchange resin is widely used due to its fast adsorption rate, easy diffusion of pollutants, and large treatment capacity. However, since perfluorinated compounds in actual water environment often exist at trace concentration level, and the water body contains various coexisting anion pollutants with concentrations much higher than that of perfluorinated compounds, the conventional ion exchange resin does not have selectivity for the removal of perfluorinated compounds, and it is difficult to efficiently and selectively remove perfluorinated compounds in actual complex water body. In addition, the traditional gel-type ion exchange resin will swell in solution, with large volume change rate and low mechanical strength. When dehydrated or compressed, the network is prone to collapse, and when over-swelled or subjected to swelling stress, the network is prone to breakage and disintegration. Therefore, it is difficult to use it stably for a long time in actual industrial application, which affects the stability of the reaction container.

[0004] Therefore, the present application provides a substance for efficiently adsorbing and removing perfluorinated compounds at trace PFAS level in complex water matrix environment and an application method thereof. SUMMARY

[0005] Technical problems solved by the present application: The present application aims to provide a kind of gel type composite nanomaterial capable of stable and efficient adsorption removal of perfluorinated compounds in complex and large water environment and provide its application method.

[0006] Technical scheme: A gel type composite nanomaterial for removing perfluoro and polyfluoro alkyl substances is prepared by the following steps:

[0007] (1) The gel type strong alkaline anion resin with quaternary ammonium group as functional group is placed in the anion solution of zirconium / iron / manganese for reaction for 6-8h, the resin is filtered out and dried;

[0008] (2) Add alkali solution, stir for 4-8h, and then filter out the resin;

[0009] (3) The resin is transformed by using mixed solution of acid and chloride salt for 4-6h, and after cleaning and drying, the gel type composite nanomaterial is obtained.

[0010] The gel type composite nanomaterial of the present application uses gel type resin, which has small pores and high functional group density, and is more suitable for rapid adsorption of perfluoro and polyfluoro substances. However, when using the "precursor introduction-explosive nucleation" strategy for precipitation preparation, due to the existence of small pores and electrostatic repulsion of quaternary ammonium groups, it is difficult for metal precursors to enter the pores of the resin. In the present application, the gel type strong alkaline anion resin with quaternary ammonium group as functional group is impregnated with zirconium / iron / manganese salt solution. The quaternary ammonium groups in the resin can electrostatically combine with the complex anions in the zirconium / iron / manganese salt solution, effectively increasing the retention rate of zirconium / iron / manganese ions on the resin and improving the uniformity of their distribution in the resin. Then the zirconium / iron / manganese anions remaining in the resin are alkalinized and transformed to form zirconium / iron / manganese oxide nanoparticles uniformly filled in the pores of the resin. By uniformly loading nanoparticles, the mechanical strength of the gel resin base can be effectively improved, the network support of the gel resin is enhanced, and its compression resistance is significantly improved to prevent structure collapse. At the same time, the interaction between nanoparticles and polymer chains can effectively restrain the stretching of the gel network, and uniformly distributed nanoparticles can reduce the internal stress caused by excessive swelling, thereby reducing the risk of swelling and breaking.

[0011] In the gel type composite nanomaterial, the quaternary ammonium groups on the resin skeleton have two functions: one is to electrostatically attract zirconium / iron / manganese complex anions, promote metal ions to enter the resin and increase their retention rate; the other is that after alkalinization and transformation, the anions on the quaternary ammonium groups are separated, and the quaternary ammonium groups are released again, so that the quaternary ammonium groups and nano zirconium / iron / manganese oxide cooperate with each other, and in the presence of competitive ions, they still show high selectivity to perfluorinated compounds.

[0012] Further, in step (1), the zirconium / iron / manganese salt solution is a fluorozirconate / ferric chloride / manganese chloride solution, respectively.

[0013] Further, in step (1), the functional group of the gel type strong basic anion resin with quaternary ammonium group is a skeleton of poly (styrene-divinylbenzene), and the mass ratio of divinylbenzene in the skeleton is 4%-7%.

[0014] Further, the solid-liquid ratio of the gel type strong basic anion resin and the zirconium / iron / manganese anion solution is 10-50 g / L, and the concentration of the zirconium / iron / manganese anion solution is 20-50 g / L.

[0015] Further, the mass fraction of metal ions in the gel type composite nanomaterial is 8-12%, and the content of quaternary ammonium group is 2.5-3.5 mmol / g.

[0016] Further, in step (2), the alkali solution is a sodium hydroxide or potassium hydroxide solution with a mass fraction of 5-10%.

[0017] Further, in step (3), the acid is 2-5wt% hydrochloric acid, and the chloride salt is 5-10wt% sodium chloride.

[0018] The application also provides a method for using the above-mentioned gel type composite nanomaterial for removing perfluoro and polyfluoro alkyl substances, which comprises the following steps:

[0019] (1) First, the gel type composite nanomaterial is swelled in pure water for more than 6h;

[0020] (2) Then, the swelled material is placed in an adsorption column;

[0021] (3) A mixed solution containing a plurality of perfluoro and polyfluoro alkyl substances is flowed through the adsorption column at a constant flow rate to obtain a defluorinated liquid.

[0022] Further, the perfluoro compound and polyfluoro alkyl substance are one or more of perfluoro octanoic acid, perfluoro butyric acid, perfluoro octane sulfonic acid, perfluoro butane sulfonic acid, perfluoro pentanoic acid, perfluoro hexanoic acid, and hexafluoropropylene oxide dimer carboxylic acid.

[0023] Beneficial effects: Compared with the prior art, the significant advantages of the present application are: the method loads zirconium oxide / iron oxide / manganese oxide nanoparticles on a gel type strong basic anion resin to obtain a gel type composite nanomaterial with a pore volume of 0.001-0.01 cm 3 / g, and the absolute swelling rate is 1.05-1.25, so that the adsorption effect can be good under different pH and coexisting ion conditions, and through the composite nanoparticles, effective support can be provided to prevent collapse, and excessive swelling can be limited to prevent breakage; and the gel type composite nanomaterial of the application can be recycled through desorption regeneration, and the regeneration bed volume change rate and desorption swelling rate are stable, the desorption time is 6-8 hours, the gel type composite nanomaterial volume change rate is 0.9-1.1, and the desorption swelling rate is 0.9-1.05. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 Adsorption kinetics curve of gel type composite nanomaterial prepared in example 1 of the application for perfluorinated compound removal;

[0025] Figure 2 Adsorption isotherm curve of gel type composite nanomaterial prepared in example 1 of the application for perfluorinated compound removal;

[0026] Figure 3 Removal effect diagram of gel type composite nanomaterial prepared in example 1 of the application for perfluorobutyric acid (PFBA) under different pH conditions;

[0027] Figure 4 Removal effect diagram of gel type composite nanomaterial prepared in example 1 of the application for perfluorobutyric acid (PFBA) under different coexisting ion sulfate ion concentration;

[0028] Figure 5 Removal effect diagram of gel type composite nanomaterial prepared in example 1 of the application for perfluorobutyric acid (PFBA) under different coexisting organic matter humic acid (HA) concentration;

[0029] Figure 6 Desorption rate effect diagram of gel type composite nanomaterial prepared in example 1 of the application after cyclic regeneration;

[0030] Figure 7 Column adsorption effect diagram of gel type composite nanomaterial prepared in example 1 of the application;

[0031] Figure 8 Structure principle diagram of gel type composite nanomaterial prepared in example 1 of the application. DETAILED DESCRIPTION

[0032] The technical solutions of the application will be further described in detail below in combination with the drawings and examples.

[0033] It should be noted that the skeleton of the gel type strong basic anion resin used in the present application is polystyrene, and the functional group is quaternary ammonium group. The resin is purchased from Zhejiang Zhengguang Resin Co., Ltd. and is a publicly known resin. The mass percentage of divinylbenzene in the skeleton is 4%, and the quaternary ammonium group content is 2.5 mmol / g.

[0034] In addition, the calculation of the loading amount of the metal in the present application is obtained by measuring the content of the metal element in the resin after the loading reaction and then digesting the resin with a strong acid.

[0035] Example 1

[0036] This example prepares a gel type composite nanomaterial with a zirconium ion loading amount of 9.1%, which specifically includes the following preparation steps:

[0037] (1) 10 g of gel type strong basic anion resin is washed and dried, and then is put into 200 ml of a 25 g / L potassium fluorozirconate solution. The solid-liquid ratio of the gel type strong base resin to the potassium fluorozirconate solution is 50 g / L, and the concentration of the potassium fluorozirconate is 25 g / L. The stirring immersion is performed for 8 h;

[0038] (2) The resin after stirring and immersion in step (1) is filtered out and is naturally dried in a ventilated place for standby;

[0039] (3) 200 ml of a 5 wt% sodium hydroxide solution is slowly added to the resin dried in step (2), and stirring reaction is performed for 4 h;

[0040] (4) A mixed solution of 2 wt% hydrochloric acid and 5 wt% sodium chloride is slowly added to the resin filtered out in step (3). The solid-liquid ratio of the filtered resin to the mixed solution is 50 g / L. The stirring is performed for 4 h at room temperature;

[0041] (5) The resin in step (4) is taken out, washed with pure water until neutral, and then dried to obtain a gel resin-based nanometer zirconia material with a loading amount of 9.1%. The structure is as shown in Figure 8 , and the nanometer zirconia ions are uniformly distributed in the voids of the gel type strong basic anion resin.

[0042] Performance detection-full fluorine compound adsorption kinetics

[0043] 0.1 g of the gel type resin composite nanometer iron oxide material prepared in Example 1 is added into 300 mL of a solution containing 100 μg / g of different full fluorine compounds, 1 g / L of sulfate ion concentration, and pH 7 to perform full fluorine compound adsorption kinetics test. 1 ml of sample is taken at 0, 15 min, 30 min, 1 h, 2 h, 4 h, 8 h, 12 h, 24 h, 48 h, and 72 h to measure the full fluorine compound concentration of the solution. The obtained results are as shown in Figure 1 . Through the Figure 1It can be known that the adsorption amounts of the composite material on perfluorooctanoic acid (PFOA), perfluorooctane sulfonic acid (PFOS), perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) can reach 365.3 μg / g, 362.9 μg / g, 101.0 μg / g, 339.7 μg / g, 150.1 μg / g, 254.6 μg / g and 214.0 μg / g respectively.

[0044] Performance test - perfluorinated compound adsorption isotherm

[0045] According to a solid-liquid ratio of 1.0 g / L, 50 mg of the gel-type composite material of Example 1 and 50 mL of a perfluorinated compound reaction solution containing different initial concentrations are added into a 100 mL conical flask, the initial solution has a pH of 7.0 ± 0.05, and the solution also contains 1000 mg / L SO4 2- to shield the adsorption of the carrier. The conical flask is continuously shaken in a constant-temperature water bath shaker at 298 K and 180 rpm for more than 96 h until the reaction is balanced, and the concentrations of various perfluorinated compounds in the solution are measured. The obtained results are shown in Figure 2 It can be known that the maximum adsorption amounts of the composite material on perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) can reach 417.7 mg / g, 1863.8 mg / g, 535.4 mg / g, 1333.0 mg / g and 643.9 mg / g respectively.

[0046] Performance test - perfluorobutyric acid adsorption pH influence

[0047] 50 mg of the gel-type composite nanomaterial and 50 mL of a PFBA solution with an initial concentration of 10 mg / L are respectively added into 150 mL conical flasks to prepare mixed systems, and 1000 mg / L SO4 2- is added to shield the adsorption of the carrier. The pH value is adjusted to form different gradients in the range of 3.0-11.0 by using hydrochloric acid and sodium hydroxide solution, and the conical flask is continuously shaken in a constant-temperature water bath shaker at 298 K and 180 rpm for 96 h until the adsorption is balanced, and the PFBA concentration in the solution is measured and the corresponding adsorption amount is calculated. The obtained results are shown in Figure 3The experimental results show that when the pH value is 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, and 11.0, the adsorption capacity of the gel-type composite nanomaterial for perfluorobutyric acid is 5.8 mg / g, 6.2 mg / g, 6.0 mg / g, 5.9 mg / g, 6.5 mg / g, 6.5 mg / g, 6.2 mg / g, 6.3 mg / g, and 6.3 mg / g, respectively.

[0048] Therefore, the gel-type composite nanomaterial can achieve good removal effect for perfluorobutyric acid in the pH value range of 3.0-11.0, and can be applied to the removal of perfluorinated compounds in a wide pH range.

[0049] Performance test - influence of coexisting ions on perfluorobutyric acid adsorption

[0050] Different concentrations of SO4 2- (0, 200, 400, 600, 800, and 1000 mg / L) were added to a 10 mg / L PFBA solution, 41 mg of gel-type composite nanomaterial and 50 mL of solution were added to a 100 mL conical flask, and continuous oscillation was carried out at 298 K and 180 rpm in a constant temperature water bath shaker for 96 h. In this process, 0.10 M sodium hydroxide and hydrochloric acid solution were used to stabilize the solution pH value at 7.0 ± 0.05. After adsorption equilibrium, the PFBA concentration in the solution was determined and the corresponding adsorption capacity was calculated. The obtained results are shown in Figure 4 The experimental results show that when the concentration of SO4 2- is 0, 200, 400, 600, 800, and 1000 mg / L, the adsorption capacity of the gel-type composite nanomaterial for perfluorobutyric acid is 12.8 mg / g, 10.8 mg / g, 8.6 mg / g, 7.9 mg / g, 7.1 mg / g, and 6.5 mg / g, respectively.

[0051] As shown in Figure 8 , the gel-type composite nanomaterial can achieve certain removal effect for perfluorobutyric acid in different coexisting ion concentration ranges. Due to its structural characteristics, fluoride will be selectively adsorbed under the action of quaternary ammonium groups and nanoparticles, and can be applied to the removal of perfluorinated compounds in the presence of coexisting ions.

[0052] Performance test - influence of coexisting organic matter on perfluorobutyric acid adsorption

[0053] Humic acid with different concentration gradient (0, 10, 50, 100, 200, 500 mg / L) was added to 10 mg / L PFBA solution, 41 mg of the composite material prepared in Example 1 and 50 mL of the solution were added to a 100 mL conical flask, and the continuous oscillation was carried out in a constant temperature water bath shaker at 298 K and 180 rpm for 96 h, and 0.10 M sodium hydroxide and hydrochloric acid solution were used to stabilize the pH value of the solution at 7.0 ± 0.05 during the process. After the adsorption was balanced, the PFBA concentration in the solution was determined and the corresponding adsorption amount was calculated. The results obtained are shown in Figure 5 The experimental results show that when the concentration of humic acid is 0, 10, 50, 100, 200, 500 mg / L, the adsorption amount of the gel type composite nanomaterial on perfluorobutyric acid is 12.7 mg / g, 12.8 mg / g, 12.9 mg / g, 12.7 mg / g, 12.8 mg / g, and 12.5 mg / g, respectively.

[0054] Therefore, the gel type composite nanomaterial can exhibit good removal effect on perfluorobutyric acid in different coexisting organic matter concentration ranges, and can be applied to the removal of perfluorinated compounds in the presence of coexisting organic matter.

[0055] Regeneration cycle adsorption performance test

[0056] The gel type composite nanomaterial of Example 1 was continuously subjected to 5 cycles of "adsorption-desorption-regeneration" test, and the desorption method was to use 1 wt% NaCl-70 wt% methanol mixed solution to flow through the adsorption column from top to bottom at a constant desorption flow rate of 10 BV / h, and the desorption time was 6-8 hours. The results obtained in the specific desorption are shown in Figure 6 The adsorbed perfluorinated compounds of the composite material of the application can be effectively desorbed by 1 wt% NaCl-70 wt% methanol mixed solution, and the desorption rate of each cycle is more than 90%; the bed volume change rate in the regeneration process is 0.9-1.1, and the desorption swelling rate is 0.9-1.05. In addition, the adsorption effect of the composite material of Example 1 does not decrease significantly after 5 cycles of "adsorption-desorption-regeneration", and the ability to remove perfluorinated compounds can be effectively restored by NaCl-methanol solution treatment.

[0057] Performance test-column adsorption

[0058] The column adsorption test of the application was carried out by simulating the actual wastewater. The specific application method comprises the following steps:

[0059] (1) 8 g of the gel type composite nanomaterial prepared in Example 1 was swelled in pure water for 7 h;

[0060] (2) Then take 5 ml of the fully swollen material and place it in an adsorption column with a diameter of 14 mm;

[0061] (3) Use a peristaltic pump to flow the fluoride mixed solution through the adsorption column from top to bottom at a constant flow rate of 40 BV / h, and the effluent concentration is less than 80 ng / L, and use an automatic collector to collect effluent samples at certain time intervals.

[0062] As shown in Figure 7 , the water treatment capacity of the composite material for PFOS is 13800 BV, the water treatment capacity for PFOA is 7880 BV, the water treatment capacity for GenX is 4920 BV, and the water treatment capacity for PFBS is 17080 BV, indicating that the composite material has good treatment effect on various perfluoro and polyfluoro compounds in practical application.

[0063] Mechanical strength determination

[0064] Put 15 mL of the gel-type composite nanomaterial prepared in Example 1 and 45 mL of deionized water into a ball mill tank, and then add 30 mL of steel balls (Φ 5 mm). The ball mill is kept rotating at a speed of 140 r / min for 30 min. Take out the sample, dry it at 60 ℃ for 3 h, and calculate the percentage of the broken sample in the whole. The broken sample percentage of Example 1 is 1%, that is, after ball milling, the sample of intact particles accounts for 99% of the whole, and the gel-type composite nanomaterial prepared in Example 1 has high mechanical strength.

[0065] Comparative Example 1

[0066] The zirconium oxide powder in this comparative example 1 is used for adsorption detection.

[0067] According to the solid-liquid ratio of 1.0 g / L, 50 mg of zirconium oxide powder and 50 mL of perfluorinated compound reaction solution containing different initial concentrations are added into a 100 mL conical flask, the initial solution pH is 7.0 ± 0.05, and the solution also contains 1000 mg / L SO4 2- . The conical flask is continuously shaken in a constant temperature water bath shaker at 298 K and 180 rpm for more than 96 h until the reaction reaches equilibrium, and the concentrations of various perfluorinated compounds in the solution are determined. It can be known from the test that the maximum adsorption capacity of the gel-type strong basic anion resin for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) can reach 42.6 mg / g, 68.7 mg / g, 51.2 mg / g, 61.5 mg / g and 37.4 mg / g, respectively.

[0068] Comparative Example 2

[0069] In this scheme, only gel-type strong basic anion resin with polystyrene backbone and quaternary ammonium group as functional group was used for the adsorption test of perfluorinated compounds.

[0070] According to the solid-liquid ratio of 1.0 g / L, 50 mg of gel-type strong basic anion resin and 50 mL of reaction solution containing different initial concentrations of perfluorinated compounds were added into a 100 mL conical flask, the resin had been swelled in pure water for 7 hours, the initial solution pH was 7.0 ± 0.05, and the solution also contained 1000 mg / L SO4 2- to shield the adsorption of the carrier. The conical flask was continuously shaken in a constant temperature water bath shaker at 298 K, 180 rpm for more than 96 h until the reaction reached equilibrium, and the concentrations of various perfluorinated compounds in the solution were determined. It was found that the maximum adsorption capacities of gel-type strong basic anion resin for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) were 328.7 mg / g, 1356.9 mg / g, 417.2 mg / g, 1039.4 mg / g and 588.4 mg / g, respectively.

[0071] The gel-type strong basic anion resin with polystyrene backbone and quaternary ammonium group as functional group was subjected to mechanical strength determination. The gel material and 45 mL of deionized water were placed in a ball mill jar, and 30 mL of steel balls (Φ 5 mm) were added. The ball mill was kept rotating at a speed of 140 r / min for 30 min. The sample was taken out and dried at 60 ℃ for 3 h, and the percentage of broken sample in the whole was calculated. The broken sample percentage of Comparative Example 2 was 9.1%, i.e. after ball milling, the sample of intact particles accounted for 90.9% of the whole. It can be seen that the gel-type strong basic anion resin with pure polystyrene backbone and quaternary ammonium group as functional group in Comparative Example 2 has poor mechanical properties and is easy to break under the action of high pressure and high impact in actual application.

[0072] Comparative Example 3

[0073] The preparation method of the adsorption material of this comparative example 3 is basically the same as that of Example 1, except that gel-type strong basic anion resin with polystyrene backbone and pyridine group as functional group was used to complex with potassium fluorozirconate to form gel-type strong basic anion resin with polystyrene backbone and pyridine group as functional group composite nano zirconium oxide material, and the adsorption test of perfluorinated compounds was carried out.

[0074] According to the solid-liquid ratio of 1.0 g / L, 50 mg of the composite material of this comparative example 3 and 50 mL of reaction solution containing different initial concentrations of perfluorinated compounds were added into a 100 mL conical flask, and the initial solution pH was 7.0 ± 0.05, and the solution also contained 1000 mg / L SO42- The conical flask was continuously shaken at 298 K, 180 rpm in a constant temperature water bath shaker for more than 96 h until the reaction reached equilibrium, and the concentrations of various perfluorinated compounds in the solution were determined. It was found that the maximum adsorption capacity of the comparative composite material for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) was 198.3 mg / g, 1065.9 mg / g, 346.1 mg / g, 873.6 mg / g and 387.4 mg / g, respectively.

[0075] The 15 mL of the gel-type composite nanomaterial prepared in Comparative Example 3 and 45 mL of deionized water were placed in a ball mill tank, and 30 mL of steel balls (Φ 5 mm) were added. The ball mill was kept rotating at a speed of 140 r / min for 30 min. The sample was taken out and dried at 60 ℃ for 3 h, and the percentage of the broken sample in the whole was calculated. The broken sample accounted for 6.6% of the whole in Comparative Example 3, that is, after ball milling, the sample of intact particles accounted for 93.4% of the whole, and the mechanical strength of the gel-type composite nanomaterial prepared in Comparative Example 3 was low.

[0076] From the perfluorinated compound adsorption detection data of Example 1 and Comparative Examples 1-3, it can be seen that the adsorption capacity of pure zirconium oxide for perfluorinated compounds in Comparative Example 1 is very limited, and the adsorption of pure gel-type strong alkaline anion resin with quaternary ammonium group as the functional group for perfluorinated compounds in Comparative Example 2 is not as good as that of Example 1, because the zirconium oxide nanoparticles and the strong alkaline anion resin can improve the adsorption performance of fluorides; and the mechanical strength of the same gel resin in Comparative Example 2 is low, which is not suitable for actual production.

[0077] In Comparative Example 3, gel-type strong alkaline anion resin with pyridyl as the functional group was compounded with potassium fluozirconate to prepare gel composite nanometer zirconia material, and the adsorption test of perfluorinated compounds showed that the adsorption effect was slightly worse and the mechanical strength was greatly reduced. It can be seen that the gel-type strong alkaline anion resin with pyridyl as the functional group cannot be compounded with potassium fluozirconate to adsorb zirconium anions into the resin, and cannot effectively form nanoparticles.

[0078] Example 2

[0079] The gel resin-based composite nanomaterial structure of this example is a gel-type strong alkaline anion resin with polystyrene as the skeleton and quaternary ammonium group as the functional group, and zirconium oxide particles loaded in the resin, with a zirconium element loading of 8.2%.

[0080] The preparation steps of the composite material of this example are the same as those of Example 1, except that 200 ml of a 20 g / L potassium fluozirconate solution is added in step (1).

[0081] Performance test - perfluorinated compound adsorption

[0082] According to a solid-liquid ratio of 1.0 g / L, 50 mg of the composite material of Example 2 and 50 mL of a perfluorinated compound reaction solution with different initial concentrations are added into a 100 mL conical flask, the initial solution pH is 7.0 ± 0.05, and the solution also contains 1000 mg / L SO4 2- to shield the adsorption of the carrier. The conical flask is continuously shaken in a constant-temperature water bath shaker at 298 K and 180 rpm for 96 h or more until the reaction reaches equilibrium, and the concentrations of various perfluorinated compounds in the solution are determined. It is found that the maximum adsorption amounts of the composite material of the application for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), and hexafluoropropylene oxide dimer carboxylic acid (GenX) are 403.7 mg / g, 1792.5 mg / g, 502.4 mg / g, 1286.9 mg / g, and 672.1 mg / g, respectively.

[0083] Mechanical strength determination

[0084] Put 15 mL of the gel-type composite nanomaterial prepared in Example 2 and 45 mL of deionized water into a ball mill tank, and then add 30 mL of steel balls (Φ 5 mm). The ball mill is kept rotating at a speed of 140 r / min for 30 min. The sample is taken out and dried at 60 ℃ for 3 h, and the percentage of the broken sample in the whole is calculated. The broken sample percentage of Example 2 is 2.9%, that is, after ball milling, the sample of intact particles accounts for 97.1% of the whole.

[0085] Example 3

[0086] The gel resin-based nanocomposite material of this example has a structure of polystyrene as a skeleton, a gel-type strong alkaline anion resin with quaternary ammonium groups as a functional group, and zirconium oxide loaded in the resin, and the zirconium element loading amount is 11.3%. The preparation steps of the composite material of this example are the same as those of Example 1, except that 200 ml of a 50 g / L potassium fluozirconate solution is added in step (1).

[0087] Performance test - perfluorinated compound adsorption

[0088] at a solid-liquid ratio of 1.0 g / L in a 100 mL conical flask, 50 mg of the composite material of Example 3 and 50 mL of a perfluorinated compound reaction solution containing different initial concentrations were added, the initial solution pH was 7.0 ± 0.05, and the solution also contained 1000 mg / L SO4 2- to shield the adsorption of the carrier. The conical flask was continuously shaken in a constant temperature water bath shaker at 298 K, 180 rpm for more than 96 h until the reaction reached equilibrium, and the concentrations of various perfluorinated compounds in the solution were determined. It was found that the maximum adsorption capacity of the composite material of the application for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) was 498.5 mg / g, 1896.9 mg / g, 551.8 mg / g, 1427.6 mg / g, and 677.3 mg / g, respectively.

[0089] Mechanical strength determination

[0090] Put 15 mL of the gel-type composite nanomaterial prepared in Example 3 and 45 mL of deionized water into a ball mill jar, and then add 30 mL of steel balls (Φ 5 mm). The ball mill is kept rotating at a speed of 140 r / min for 30 min. Take out the sample and dry it at 60 ℃ for 3 h, and calculate the percentage of the broken sample in the whole. The broken sample percentage of Example 3 is 0.7%, that is, after ball milling, the sample of intact particles accounts for 99.3% of the whole.

[0091] Example 4

[0092] The preparation steps of the composite material of this example are basically the same as those of Example 1, except that the potassium fluorozirconate solution is replaced by an iron chloride solution, and 200 ml of 25 g / L iron chloride is added in step (1). The final product has an iron element loading of 9%.

[0093] Performance detection - perfluorinated compound adsorption

[0094] at a solid-liquid ratio of 1.0 g / L in a 100 mL conical flask, 50 mg of the composite material of Example 3 and 50 mL of a perfluorinated compound reaction solution containing different initial concentrations were added, the initial solution pH was 7.0 ± 0.05, and the solution also contained 1000 mg / L SO4 2-to shield the adsorption of the carrier. The conical flask is continuously shaken at 298 K and 180 rpm in a constant temperature water bath shaker for more than 96 h until the reaction reaches equilibrium, and the concentrations of various perfluorinated compounds in the solution are determined. It is found that the maximum adsorption amounts of the composite material for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA), and hexafluoropropylene oxide dimer carboxylic acid (GenX) can reach 381.0 mg / g, 1680.2 mg / g, 461.2 mg / g, 1281.1 mg / g, and 596.4 mg / g, respectively.

[0095] Mechanical strength determination

[0096] Put 15 mL of the gel-type composite nanomaterial prepared in Example 4 and 45 mL of deionized water into a ball mill tank, and then add 30 mL of steel balls (Φ 5 mm). The ball mill is kept rotating at a speed of 140 r / min for 30 min. Take out the sample, dry it at 60 ℃ for 3 h, and calculate the percentage of the broken sample in the whole. The percentage of the broken sample in Example 4 is 2.6%, that is, after ball milling, the sample of intact particles accounts for 97.4% of the whole.

[0097] Example 5

[0098] The gel resin-based composite nanomaterial structure of this example is a gel-type strong alkaline anion resin with polystyrene as the skeleton, a functional group of quaternary ammonium group, and iron oxide loaded in the resin, and the loading amount of iron element is 11%.

[0099] The preparation steps of the composite material of this example are the same as those of Example 1, except that 200 ml of 50 g / L ferric chloride is added in step (1).

[0100] Performance detection - perfluorinated compound adsorption

[0101] According to a solid-liquid ratio of 1.0 g / L, 50 mg of the composite material of Example 5 and 50 mL of a reaction solution containing different initial concentrations of perfluorinated compounds are added into a 100 mL conical flask, the initial solution pH is 7.0 ± 0.05, and the solution also contains 1000 mg / L SO4 2-to shield the adsorption of the carrier. The conical flask is continuously shaken at 298 K and 180 rpm in a constant-temperature water bath shaker for 96 h or more until the reaction reaches equilibrium, and the concentration of various perfluorinated compounds in the solution is determined. Tests show that the maximum adsorption capacity of the composite material for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) can reach 415.7 mg / g, 1802.7 mg / g, 488.8 mg / g, 1305.7 mg / g and 672.5 mg / g, respectively.

[0102] Mechanical strength determination

[0103] Put 15 mL of the gel-type composite nanomaterial prepared in Example 5 and 45 mL of deionized water into a ball mill tank, and then add 30 mL of steel balls (Φ 5 mm). The ball mill is kept rotating at a speed of 140 r / min for 30 min. Take out the sample and dry it at 60°C for 3 h, and calculate the percentage of the broken sample in the whole. The broken sample percentage of Example 5 is 1.5%, that is, after ball milling, the sample of intact particles accounts for 98.5% of the whole.

[0104] Example 6

[0105] The gel resin-based composite nanomaterial structure of this example is a gel-type strong alkaline anion resin with polystyrene as the skeleton and quaternary ammonium groups as the functional groups, and manganese oxide loaded in the resin, with a manganese element loading of 9.2%.

[0106] The preparation steps of the composite material of this example are the same as those of Example 1, except that in step (1), 200 ml of manganese chloride solution with a concentration of 20 g / L is used.

[0107] Performance detection - perfluorinated compound adsorption

[0108] According to a solid-liquid ratio of 1.0 g / L, 50 mg of the composite material of Example 6 and 50 mL of a reaction solution containing different initial concentrations of perfluorinated compounds are added to a 100 mL conical flask, the initial solution pH is 7.0 ± 0.05, and the solution also contains 1000 mg / L SO4 2-To shield the adsorption effect of the carrier, the conical flask was continuously shaken at 298 K and 180 rpm in a constant temperature water bath shaker for more than 96 hours until the reaction reached equilibrium. The concentrations of various perfluorinated compounds in the solution were measured. The experiment showed that the maximum adsorption capacity of the composite material of the present invention for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluorovalerate (PFPeA), perfluorohexanoic acid (PFHxA), and hexafluoropropylene oxide dimercarboxylic acid (GenX) reached 373.2 mg / g, 1686.2 mg / g, 468.0 mg / g, 1248.7 mg / g, and 584.9 mg / g, respectively.

[0109] Mechanical strength test

[0110] 15 mL of the gel-type composite nanomaterial prepared in Example 6 and 45 mL of deionized water were placed in a ball mill jar, followed by 30 mL of steel balls (Φ 5 mm). The ball mill was maintained at 140 r / min for 30 min. The sample was then removed and dried at 60 ℃ for 3 h, and the percentage of broken samples was calculated. The percentage of broken samples in Example 6 was 2.2%, meaning that after ball milling, the sample contained 97.8% intact particles.

[0111] Example 7

[0112] The structure of the gel resin-based composite nanomaterial in this embodiment is a gel-type strong basic anion exchange resin with polystyrene as the skeleton and quaternary ammonium groups as functional groups, and manganese oxide loaded in the resin, with a manganese loading of 11.9%.

[0113] The preparation steps of the composite material in this embodiment are the same as those in Example 1, except that in step (1), 200 ml of manganese chloride solution with a concentration of 50 g / L is used.

[0114] Performance Testing—Adsorption of Perfluorinated Compounds

[0115] At a solid-liquid ratio of 1.0 g / L, 50 mg of the composite material from Example 7 and 50 mL of reaction solutions containing different initial concentrations of perfluorinated compounds were added to 100 mL Erlenmeyer flasks. The initial solution pH was 7.0 ± 0.05, and the solution also contained 1000 mg / L SO4. 2-The adsorption of the shielding carrier is shielded. The conical flask is continuously shaken at 298 K and 180 rpm in a constant-temperature water bath shaker for 96 hours or more until the reaction is balanced, and the concentration of various perfluorinated compounds in the solution is determined. It is found that the maximum adsorption amount of the composite material for perfluorobutyric acid (PFBA), perfluorobutane sulfonic acid (PFBS), perfluoropentanoic acid (PFPeA), perfluorohexanoic acid (PFHxA) and hexafluoropropylene oxide dimer carboxylic acid (GenX) can reach 405.6 mg / g, 1790.3 mg / g, 474.3 mg / g, 1298.1 mg / g and 639.4 mg / g, respectively.

[0116] Mechanical strength determination

[0117] Put 15 mL of the gel-type composite nanomaterial prepared in Example 7 and 45 mL of deionized water into a ball mill tank, and then add 30 mL of steel balls (Φ 5 mm). The ball mill is kept rotating at a speed of 140 r / min for 30 min. Take out the sample, dry it at 60 DEG C for 3 h, and calculate the percentage of the broken sample in the whole. The broken sample percentage of Example 7 is 1.1%, that is, after ball milling, the sample of intact particles accounts for 98.9% of the whole.

[0118] In addition to the above examples, it should be noted that the gel-type composite nanomaterial prepared by the method of the present application is placed in a zirconium / iron / manganese anion solution, and the reaction time can be 6-8 h; the solid-liquid ratio of the gel-type strong basic anion resin to the zirconium / iron / manganese anion solution can be 10-50 g / L; the concentration of the zirconium / iron / manganese anion solution can be 20-50 g / L; the mass fraction of metal ions in the gel-type composite nanomaterial can be 8-12%, and the quaternary ammonium group content can be 2.5-3.5 mmol / g; the alkali solution can be a 5-10% mass fraction sodium hydroxide or potassium hydroxide solution; the acid used can be 2-5wt% hydrochloric acid, and the chloride salt used can be 5-10wt% sodium chloride.

[0119] That is, using the preparation process and the defined parameter range of the present application, the technical effects claimed by the present application can be achieved, and therefore it is no longer necessary to individually cite evidence.

Claims

1. Use of a gel-type composite nanomaterial in the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, The application comprises the following steps: (1) first, take the gel type composite nanomaterial to swell in pure water for more than 6 hours; (2) then take the swelled material and place it in an adsorption column; (3) flow a mixed solution containing a plurality of perfluorinated compounds and polyfluoroalkyl substances through the adsorption column at a constant flow rate to obtain a liquid after defluorination; The gel type composite nanomaterial is prepared by the following steps: 1) place the gel type strong alkaline anion resin with quaternary ammonium group as functional group in a zirconium or iron or manganese anion solution for 6-8 hours, filter out the resin and air dry; and the zirconium or iron or manganese anion solution is fluorozirconate solution, ferric chloride solution or manganese chloride solution, respectively; 2) add an alkali solution, stir for 4-8 hours and then filter out the resin; 3) use a mixed solution of acid and chloride salt to transform the resin for 4-6 hours, and after cleaning and drying, the gel type composite nanomaterial is obtained.

2. Use of the gel-type composite nanomaterial according to claim 1 for the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, The skeleton of the gel type strong alkaline anion resin with quaternary ammonium group as functional group is poly(styrene-divinylbenzene), and the mass fraction of divinylbenzene in the skeleton is 4%-7%.

3. Use of the gel-type composite nanomaterial according to claim 1 for the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, The solid-liquid ratio of the gel type strong alkaline anion resin to the fluorozirconate or ferric chloride or manganese chloride solution is 10-50 g / L, and the concentration of the fluorozirconate or ferric chloride or manganese chloride solution is 20-50 g / L.

4. Use of the gel-type composite nanomaterial according to claim 1 for the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, The mass fraction of metal ions in the gel type composite nanomaterial is 8-12%, and the content of quaternary ammonium group is 2.5-3.5 mmol / g.

5. Use of the gel-type composite nanomaterial according to claim 1 for the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, In step 2), the alkali solution is a sodium hydroxide or potassium hydroxide solution with a mass fraction of 5-10%.

6. Use of the gel-type composite nanomaterial according to claim 1 for the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, In step 3), the acid is hydrochloric acid with a weight fraction of 2-5%, and the chloride salt is sodium chloride with a weight fraction of 5-10%.

7. Use of the gel-type composite nanomaterial according to claim 1 for the removal of perfluorinated and polyfluoroalkyl substances, characterized in that, The perfluorinated compounds and polyfluoroalkyl substances are one or more of perfluorooctanoic acid, perfluorobutyric acid, perfluorooctanesulfonic acid, perfluorobutanesulfonic acid, perfluoropentanoic acid, perfluorohexanoic acid, and hexafluoropropylene oxide dimer carboxylic acid.

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