Modified resin, preparation method and application of modified resin in removal of organic amine in water

Abstract

The invention discloses modified resin, a preparation method and application of the modified resin in removal of organic amine in water, and belongs to the technical field of water pollution control. The preparation method comprises the following steps: soaking resin in distilled water until the resin is swelled, and then cleaning and filtering to finish pretreatment; dissolving ferric iron salt in distilled water to obtain an iron metal salt solution; soaking the pretreated resin in the iron metal salt solution; and taking out the resin from the iron metal salt solution, washing and drying to obtain the iron-containing resin. Experimental results show that the modified resin has a good removal effect on aniline in water within the pH range of 2-9, the maximum adsorption capacity can reach 178.05 mg / g, and the modified resin has high anti-interference capacity and regeneration performance and can stably remove aniline pollutants under the complex water quality condition. After adsorption saturation, the adsorbent can be regenerated and reused through 0.5 mol / L ferric sulfate and 20vt% ethanol. The method has a wide practical application prospect, and a novel solution is provided for aniline wastewater treatment and resource recycling.

Description

Technical Field

[0001] The invention belongs to the technical field of water pollution control, and in particular relates to a modified resin, a preparation method and application thereof in removing organic amines from water. Background Art

[0002] Organic amines are common industrial raw materials, widely used in dyes, rubber additives, pesticides and pharmaceutical intermediates. However, organic amines are highly toxic and carcinogenic. Long-term exposure can harm the central nervous system, liver and kidneys. Once they pollute water bodies, they are difficult to be effectively removed by traditional sewage treatment methods due to their high solubility and poor biodegradability, thus seriously threatening water quality and the ecological environment.

[0003] Existing technologies have made some progress in treating organic amine wastewater, but there are still obvious shortcomings. For example, the strong acid cation exchange resin D001 has a certain effect in the treatment of amine wastewater (Meng Yuanyuan. Research on the treatment of dimethylamine wastewater with ion exchange resin [D]. Zhejiang University, 2011), but its anti-interference ability is weak, and the adsorption capacity is low under high concentration of inorganic salt or high pH conditions. The complex precipitation method shows a high removal rate (≥97%) for aniline removal, but due to the need to add a large amount of chemical agents and incomplete recovery of precipitation particles, there is a problem of secondary pollution (Liu Yan. Treatment of aniline-containing wastewater by complex precipitation technology [J]. Dyes and Coloring, 2017, 54(03): 58-61.). Therefore, the development of new adsorption materials with high selectivity, strong anti-interference, no secondary pollution, and recyclability has become an urgent problem to be solved.

[0004] In contrast, ion exchange resins modified by metal ions can be used as adsorbents with certain selectivity and strong anti-interference performance. For example, Dong Suiming et al. used ferric chloride to modify the resin as a defluorinating agent, and the saturated adsorption capacity could reach 12.36 mg / g (Dong Suiming, Li Peicheng, Zhou Xiaode. Preparation and defluorination research of 732 modified resin defluorinating agent [J]. Journal of Northwest A&F University (Natural Science Edition), 2006, (01): 129-132). Yanhong Chao et al. used metal ions to impregnate strong acid polystyrene resin D001 for the removal of antibiotics. The adsorption rate of antibiotics in water by the modified resin reached more than 98%. (Chao Y, Zhu W, Ye Z, et al. Preparation of metal ions impregnated polystyrene resins for adsorption of antibiotics contaminants in aquatic environment [J]. Journal of Applied Polymer Science, 2015, 132 (15)), Ma Yulong applied for a method for removing tetracycline from water using a metal ion-loaded resin. The modified resin has a removal rate of more than 97% for tetracycline in water. (Ma Yulong, Wu Feng, Song Zhi, et al. A method for removing residual tetracycline in water using adsorption [P]. Ningxia: CN201711070366.6, 2018-03-13), Li Xiaojun applied for a method for preparing an iron-copper bimetallic modified ion exchange material and its application, which has a significant improvement over the unmodified resin and a faster adsorption rate. (Li Xiaojun, Chen Yuqiang, Zhang Kai, et al. Preparation method and application of an iron-copper bimetallic modified ion exchange material [P]. Shaanxi Province: CN202410862651.5, 2024-09-27), etc. Although metal ion-modified ion exchange resins can be used as excellent adsorbents, they are only used for the adsorption and removal of pollutants such as fluoride ions, antibiotics, and organic phosphorus, and composite materials for the removal of organic amines have not been reported. Summary of the invention

[0005] In view of the deficiencies of the prior art, the purpose of the present invention is to provide a modified resin, a preparation method and its application in removing organic amines from water, which solves the problems of poor selectivity, narrow pH application range, secondary pollution and the like in the prior art.

[0006] The purpose of the present invention can be achieved by the following technical solutions:

[0007] A method for preparing a modified resin comprises the following steps:

[0008] The resin is soaked in distilled water until it swells, and then washed and filtered to complete the pretreatment;

[0009] Dissolving a ferric salt in distilled water to obtain an iron metal salt solution;

[0010] soaking the pretreated resin in the iron metal salt solution;

[0011] The resin is taken out from the iron metal salt solution, washed and dried to obtain the product.

[0012] Furthermore, the resin is D001 macroporous strongly acidic cation exchange resin.

[0013] Furthermore, the trivalent iron salt is ferric sulfate with a concentration of 0.5 mol / L.

[0014] Furthermore, the resin is washed with anhydrous ethanol or distilled water until there is no iron ion in the eluent; the drying temperature is 55-65° C., and the drying time is 8 hours.

[0015] A modified resin is prepared using the above-mentioned method for preparing a modified resin.

[0016] The above-mentioned modified resin is used to remove organic amines in water.

[0017] Furthermore, the application comprises the following steps:

[0018] Adjust the pH value of wastewater containing organic amines;

[0019] The modified resin is added to wastewater containing organic amines and placed in a water bath shaker or an adsorption column to remove the organic amines.

[0020] Furthermore, the pH value of the wastewater containing organic amines is 2-12.

[0021] Furthermore, the organic amine is any one of aniline, diphenylamine and p-methylaniline.

[0022] The above-mentioned method for regenerating a modified resin comprises the following steps:

[0023] The adsorption-saturated modified resin is loaded into a glass adsorption column with a water bath jacket;

[0024] Use 0.5 mol / L ferric sulfate solution and 20vt% ethanol as desorption regeneration agent to achieve desorption and regeneration at one time; set the desorption temperature to 40°C, collect the desorption liquid during the desorption process, and the desorption liquid after desorption can be appropriately supplemented with ferric sulfate to achieve multiple reuse;

[0025] After desorption, the adsorption column is rinsed with distilled water until there is no iron ion in the effluent.

[0026] Beneficial effects of the present invention:

[0027] 1. The present invention significantly improves the adsorption selectivity and pH application range of aniline pollutants by loading trivalent iron ion modified resin, has a good removal effect under the condition of pH 2-10, and the maximum adsorption capacity can reach 178.05 mg / g; it still maintains high adsorption performance in a high-concentration inorganic salt interference environment and exhibits strong anti-interference ability; it exhibits higher selectivity, removal efficiency and pH application range than unmodified resin or traditional methods, and can effectively treat aniline-contaminated water.

[0028] 2. The modified resin of the present invention can achieve a local concentration of iron ions and organic amines in the resin pores that is higher than that of the free solvent system, thereby increasing the removal depth of the organic amines. No complex precipitates exist in the solution after adsorption by the composite functional resin, and the iron ion concentration is lower than 0.3 mg / L, which can avoid the problem of secondary pollution. Desorption and regeneration can be achieved simultaneously with 0.5 mol / L ferric sulfate solution and 20 vt% ethanol, and the adsorption performance remains stable during multiple cycles. It is suitable for the removal of aniline under complex water conditions and has broad practical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0030] Figure 1 It is a microscopic morphology image and EDS spectrum image of the iron metal modified resin prepared in Example 1 of the present invention;

[0031] Figure 2 is a relationship diagram between the initial pH and the removal rate measured in Example 2 of the present invention and Comparative Example 1;

[0032] Figure 3 It is a graph showing the dynamic adsorption relationship between Example 3 of the present invention and Comparative Example 2 and the dynamic continuous adsorption-desorption performance result of the iron metal modified resin prepared in Example 3. DETAILED DESCRIPTION

[0033] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0034] Example 1

[0035] A method for preparing a modified resin comprises the following steps:

[0036] S1, resin pretreatment;

[0037] Select D001 macroporous strongly acidic cation exchange resin ("Zhengguang" brand D001 resin; Zhejiang Zhengguang Industrial Co., Ltd.), take an appropriate amount of resin, soak it in distilled water until the resin is completely swollen; then use de-distilled water to wash the swollen resin until the washing liquid is clear; filter the washed resin to ensure that there are no impurities or insolubles on the resin surface, and prepare for subsequent metal ion adsorption.

[0038] S2, preparation of metal salt solution

[0039] Weigh 20 g of ferric sulfate reagent and dissolve it in 100 mL of distilled water to obtain an iron metal salt solution with a concentration of 0.5 mol / L;

[0040] S3, metal ion modification

[0041] Weigh 10 g of the pretreated D001 resin and soak it in the iron metal salt solution prepared in S2. Keep the resin in contact with the iron salt solution for 4 hours at room temperature (25°C) to ensure that the iron ions are fully adsorbed on the resin surface.

[0042] S4, washing and drying

[0043] The resin is washed with anhydrous ethanol for several times until there is no iron ion in the eluent; the washed resin is placed in a vacuum drying oven and dried at a constant temperature of 60°C for 8 hours until the resin is completely dry to obtain an iron metal modified resin; in other embodiments, the drying temperature ranges from 55-65°C.

[0044] The iron metal modified resin was ground into powder and subjected to SEM-EDS characterization test. The test results are as follows: Figure 1 As shown; Figure 1 (a) is the SEM image result, from which it can be seen that the surface of the modified resin presents an irregular granular morphology, the particles are evenly distributed, the surface is rough and there is a significant porous structure. Figure 1 (b) is the EDS energy spectrum, from which it can be seen that the surface of the modified resin is mainly composed of three elements: S, O and Fe, among which the atomic content of Fe is as high as 29.79%, indicating that trivalent iron ions are successfully loaded onto the resin surface through electrostatic adsorption and complexation, forming a stable bond with the sulfonic acid group.

[0045] Example 2

[0046] In this embodiment, the iron metal modified resin in Example 1 is used to remove aniline from water, and the experimental steps include:

[0047] Step 1, wastewater pH adjustment

[0048] Prepare an aniline solution with an initial concentration of 600 mg / L, add HCl or NaOH solution with a concentration of 0.1 mol / L to adjust the pH value of the solution to 2, 3, 5, 7, 9, 11, 11.5, 12 respectively;

[0049] Step 2: Add iron metal modified resin adsorbent

[0050] Take 100mL and 600mg / L aniline solutions with different initial pH values ​​respectively, add 0.10g of iron metal modified resin into a stoppered conical flask, and place it in a water bath shaker; set the water bath shaker temperature to 25°C, the shaking frequency to 130r / min, and react for 24 hours.

[0051] Step 3, adsorption effect analysis:

[0052] After the reaction is completed, a sample is taken to determine the aniline concentration in the solution, and a concentration analysis is performed using an ultraviolet spectrophotometer.

[0053] Comparative Example 1

[0054] The experimental steps of Comparative Example 1 are the same as those of Example 2, except that the resin used in the experiment of Comparative Example 1 is a resin that is not modified by loading trivalent iron ions.

[0055] The relationship between the initial pH and removal rate of the solution in Example 2 and Comparative Example 1 obtained in the experiment is summarized as follows: Figure 2 ,have Figure 2 It can be seen that the aniline adsorption performance of the iron metal modified resin under different pH conditions is significantly improved, especially in the pH range of 5-9, the removal rate is stable at about 20%, showing good adsorption capacity and pH resistance; in contrast, although the unmodified resin has better adsorption performance under strong acidic conditions, with a removal rate of more than 40%, its adsorption performance decreases rapidly with the increase of pH, and the effect is poor under neutral and alkaline conditions. Overall, the modification of iron metal enhances the adsorption capacity and pH adaptability of the resin, making it show more stable performance in a wide pH range, especially at pH = 9, the adsorption amount reaches 178.05mg / g.

[0056] Example 3

[0057] In this embodiment, a method for regenerating the iron metal modified resin in Example 1 is introduced, comprising the following steps:

[0058] 1) The iron metal modified resin obtained in Example 1 was soaked in distilled water for 30 minutes, and 2 mL of the resin was loaded into a glass adsorption column with a water bath jacket.

[0059] 2) Prepare a 100 mg / L aniline solution with a pH of 9 and add 500 mg / L of competing ion Cl - 、SO4 2- 、CO3 2- .

[0060] 3) Pour the prepared aniline solution into the adsorption column, react at 25°C for 30 minutes, start the peristaltic pump, pass the resin bed at a flow rate of 6 BV / h, collect the effluent through the automatic fraction collector, and analyze the aniline concentration in the effluent;

[0061] 4) using a 0.5 mol / L iron sulfate solution and 20 vt% ethanol as a desorbent, and desorbing at a flow rate of 1 BV / h through an adsorption column;

[0062] 5) The desorption temperature was set to 40°C. During the desorption process, the desorbed liquid was collected by an automatic fraction collector;

[0063] 6) collecting the desorption liquid once every hour and analyzing the concentration of aniline therein;

[0064] 7) After desorption, the adsorption column was rinsed with distilled water until the effluent was clear and free of iron ions, and the adsorption and desorption process was repeated five times.

[0065] Comparative Example 2

[0066] The difference from Example 3 is that the resin used in the experiment of Comparative Example 2 is a resin modified without loading trivalent iron ions and only one dynamic adsorption experiment is performed.

[0067] The dynamic adsorption effect relationship between Example 3 and Comparative Example 2 and the experimental data measured after Example 3 repeated the above adsorption-desorption process 5 times are summarized in Figure 3 ,in, Figure 3 (a) is a relationship diagram of the dynamic adsorption effect of the iron-modified resin and the unmodified resin. It can be seen that the modified resin still has a relatively complete adsorption of aniline in the first 100BV, while the unmodified D001 resin has a poor adsorption effect on aniline. At 100BV, the aniline concentration in the effluent water solution is close to the inlet water concentration. Figure 3 (b) is the experimental result after 5 dynamic continuous adsorptions. It can be seen that when the influent aniline concentration is 100 mg·L -1When the aniline concentration in the solution is about 100 BV before the effluent, it is lower than the detection limit (0.003 mg / L), that is, in the first 100 BV, the aniline in the influent is almost completely adsorbed. After 5 consecutive adsorptions, it can still maintain a relatively high adsorption capacity, indicating that the iron metal modified resin has a good treatment effect on aniline. Figure 3 (c) is the experimental result after 5 dynamic continuous desorptions. It can be seen that in the first 10BV of desorption, the desorption rate of aniline on the resin has reached more than 80%. When the desorption reaches about 15BV, the desorption rate is close to 100%, indicating that the iron metal modified resin after adsorbing aniline has good desorption regeneration performance. Therefore, it is proved that the modified resin not only has strong anti-interference ability, but also can maintain a long-term stable aniline removal effect after the resin is reloaded with trivalent iron.

[0068] Example 4

[0069] In this embodiment, the iron metal modified resin in Example 1 can also be used to remove diphenylamine, p-methylaniline and other aromatic amine wastewater in water according to the methods of Examples 2 and 3, and the effects are different.

[0070] In the description of this specification, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0071] The above shows and describes the basic principles, main features and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A method for preparing a modified resin, characterized in that: The following steps are involved: The resin is soaked in distilled water until it swells, and then washed and filtered to complete the pretreatment; Dissolving a ferric salt in distilled water to obtain an iron metal salt solution; soaking the pretreated resin in the iron metal salt solution; The resin is taken out from the iron metal salt solution, washed and dried to obtain the product.

2. The method for preparing a modified resin according to claim 1, characterized in that: The resin is D001 macroporous strongly acidic cation exchange resin.

3. The method for preparing a modified resin according to claim 1, characterized in that: The trivalent iron salt is ferric sulfate, and the iron ion concentration is 1 mol / L.

4. The method for preparing a modified resin according to claim 1, characterized in that: The resin is washed with anhydrous ethanol or distilled water until there is no iron ion in the eluent; the drying temperature is 55-65° C. and the drying time is 8 hours.

5. A modified resin, characterized in that: The modified resin is prepared by the method for preparing the modified resin according to any one of claims 1 to 4.

6. Use of the modified resin according to claim 5 in removing organic amines from water.

7. The use according to claim 6, characterized in that: The following steps are involved: Adjust the pH value of wastewater containing organic amines; The modified resin is added to wastewater containing organic amines and placed in a water bath shaker or an adsorption column to remove the organic amines.

8. The use according to claim 7, characterized in that: The pH value of wastewater containing organic amines is 2-12.

9. The use according to any one of claims 6 to 8, characterized in that: The organic amine is any one of aniline, diphenylamine and p-methylaniline.

10. The method for regenerating a modified resin according to claim 5, characterized in that: The following steps are involved: The adsorption-saturated modified resin is loaded into a glass adsorption column with a water bath jacket; Use 0.5 mol / L ferric sulfate solution and 20vt% ethanol as desorption regeneration agent to achieve desorption and regeneration at one time; set the desorption temperature to 40°C, collect the desorption liquid during the desorption process, and the desorption liquid after desorption can be appropriately supplemented with ferric sulfate to achieve multiple reuse; After desorption, the adsorption column is rinsed with distilled water until there is no iron ion in the effluent.

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