Amino resin loaded nanometer palladium composite functional material, and preparation method and application thereof

Abstract

The application discloses an amino resin loaded nanometer palladium composite functional material and a preparation method and application thereof, the matrix of the composite functional material is chloromethylated polystyrene resin grafted with a polyamine group compound, the crosslinking degree of the chloromethylated polystyrene resin is 4%-8%, the particle size is 0.30-0.90 mm, and the pore size is 1-50 nm, the polyamine group compound is a compound comprising two primary amine groups and at least one secondary amine group; the matrix surface is uniformly distributed with a pore structure, and nanometer palladium particles are loaded in the pores; the loading rate of the nanometer palladium particles in the composite material is 0.25%-5% in mass percentage. The application develops a novel functional material which is efficient, stable, has the functions of adsorption enrichment and targeted reduction, realizes efficient removal efficiency of Cu-organic complex and in-situ recovery of copper elements, and realizes clean and effective treatment of water pollution and resource recovery of copper elements.

Description

Technical Field

[0001] This invention belongs to the field of industrial wastewater treatment and resource utilization technology, specifically relating to an amine resin-supported palladium nanocomposite functional material, its preparation method, and its application in in-situ reduction to remove and recover copper from Cu-organic complexes. Background Technology

[0002] In industries such as electroplating, electroless plating, printed circuit boards, and hydrometallurgy, strong complexing agents such as ethylenediaminetetraacetic acid (EDTA) and aminotriacetic acid (NTA) are widely used, resulting in industrial wastewater containing high concentrations and high stability of Cu-organic complexes (such as Cu-EDTA). These complexes, due to their strong binding and high water solubility, are far more difficult to treat than free heavy metal ions. Furthermore, this type of wastewater typically exhibits both high salinity and high organic matter concentrations, posing even greater challenges to treatment technologies.

[0003] Currently, common methods for treating complexed heavy metal wastewater include chemical precipitation, adsorption, membrane separation, and advanced oxidation. However, these methods, all aimed at separating or destroying complexes, have significant limitations: chemical precipitation requires excessive reagents and easily generates heavy metal-containing sludge, causing secondary pollution; adsorption and membrane separation only involve phase transfer and do not achieve resource recovery, and the subsequent treatment of the enriched substances remains a challenge; advanced oxidation is currently the mainstream method for treating complexed heavy metals. It indiscriminately degrades organic ligands by generating strong oxidizing free radicals (such as ·OH), thereby releasing free metal ions. Although this method can effectively destroy the complex structure, it has inherent defects: (1) The reagent or energy consumption is high. A large amount of oxidant or a large amount of electrical energy needs to be added to degrade stable organic ligands; (2) It is significantly affected by water quality. High concentrations of salt and background organic matter will seriously consume free radicals, resulting in a sharp decline in treatment efficiency; (3) Resource recovery is difficult. This method targets the mineralization of organic matter and does not solve the problem of metal resource recovery. Additional steps are still needed to precipitate or recover the released metal ions.

[0004] In contrast, reduction methods directly target the heavy metal central ions by reducing high-valence Cu-organic complexes (such as Cu(II)) to zero-valence copper (Cu(0)). This approach is highly targeted and efficient, directly attacking the core of the complex structure without completely destroying stable organic ligands, and is theoretically more energy-efficient. Furthermore, this method has resource recovery potential; the generated elemental copper is easily separated and enriched, enabling the transformation from "pollutant" to "resource." However, traditional chemical reduction methods (such as those using iron powder or sodium borohydride) also face problems such as high consumption of reducing agents, high costs, and potential secondary pollution. Electrochemical reduction methods are limited by high energy consumption, easy electrode passivation, low mass transfer efficiency in complex water bodies, and numerous side reactions. More importantly, in complex matrices with high salt and high organic matter content, the efficiency and stability of existing reduction technologies are often difficult to guarantee, severely restricting their practical application. Therefore, developing a novel functional material that is highly efficient, stable, and possesses both adsorption, enrichment, and targeted reduction capabilities to achieve efficient removal of Cu-organic complexes and recovery of copper resources has become a key breakthrough in this field.

[0005] To address the shortcomings of existing technologies where the removal of Cu-organic complexes is affected by salinity and organic matter concentration in water, making it difficult to achieve ideal removal results and recover copper from Cu-organic complexes under high salinity and high organic matter concentration conditions, this invention aims to provide a highly efficient method for the removal of Cu-organic complexes and the recovery of copper resources in high-salt and high-organic-matter wastewater. A novel functional material with high efficiency, stability, and both adsorption, enrichment, and targeted reduction capabilities has been developed to achieve high removal efficiency and in-situ recovery of copper, thereby achieving clean and effective water pollution control and copper resource recovery. Summary of the Invention

[0006] In order to solve the above-mentioned technical problems in the prior art, the purpose of this invention is to provide an amine resin-loaded palladium nanocomposite functional material, its preparation method and application.

[0007] The technical solution adopted in this invention is as follows:

[0008] A functional composite material of palladium nanoparticles loaded with an amine resin is disclosed. The matrix of the composite material is a chloromethylated polystyrene resin grafted with a polyamine group compound. The chloromethylated polystyrene resin has a crosslinking degree of 4%-8%, a particle size of 0.30-0.90 mm, and a pore size of 1-50 nm. The polyamine group compound is a compound including two primary amine groups and at least one secondary amine group. The matrix surface has a uniformly distributed porous structure, and palladium nanoparticles are loaded in the pores. The loading rate of palladium nanoparticles in the composite material is 0.25%-5% by mass percentage.

[0009] Furthermore, the polyamine group compound is diethylenetriamine, and the loading rate of palladium nanoparticles in the composite material is 0.5%-1% by mass percentage.

[0010] The method for preparing an amine resin-supported palladium nanocomposite functional material includes the following steps:

[0011] Step 1: After soaking the chloromethylated polystyrene resin in ethanol and deionized water in sequence, it is added to N,N-dimethylformamide swelling agent and swollen at room temperature for 12-24 hours. After solid-liquid separation, the swollen chloromethylated polystyrene resin is obtained.

[0012] Step 2: The chloromethylated polystyrene resin pretreated in Step 1 is grafted with the polyamine group compound for 12-24 hours to obtain an amino-functionalized resin.

[0013] Step 3: Impregnate the amino-functionalized resin in an aqueous hydrochloric acid solution containing Pd salt. The concentration of the aqueous hydrochloric acid solution is 0.4-0.8 mol / L, preferably 0.5 mol / L. The loading of Pd is completed under shaking.

[0014] Step 4: Solid-liquid separation. An excess sodium borohydride solution is added dropwise to the Pd-loaded resin. The Pd is reduced to its elemental form by ultrasonication under a nitrogen atmosphere and at room temperature. The resin is then washed and dried to obtain the amine resin-loaded palladium nanocomposite functional material.

[0015] Further, in step 2, the chloromethylated polystyrene resin is added to a polyamine group compound-ethanol mixed solution at a solid-liquid ratio of 10g:200-400ml, wherein the volume ratio of the polyamine group compound to ethanol is 1.5-2.5:1, and the grafting reaction is carried out at a temperature of 60-70℃ for 12-24h. Afterwards, it is filtered, washed and dried to obtain the amine functionalized resin.

[0016] Furthermore, the immersion temperature in step 3 is 25-40℃, and the immersion time is 2-6 hours.

[0017] Furthermore, in step 4, the molar ratio of sodium borohydride to Pd salt in step 3 is (3 ~ 10):1, and the sodium borohydride solution is an aqueous solution of sodium borohydride with a mass fraction of 0.5 ~ 3%.

[0018] The application of the amine resin-supported palladium nanocomposite functional material in the efficient removal of Cu-organic complexes and copper resource recovery from high-salt, high-organic-content wastewater includes the following steps:

[0019] S1: Adjust the pH of the high-salt, high-organic-matter water containing Cu-organic complexes to 2.0-6.0, and then filter to obtain the filtrate;

[0020] S2: Add the amine resin-supported palladium nanocomposite functional material to the filtrate obtained in step S1, controlling the addition amount to 0.2-0.8 g / L, and carry out the reaction at 20-40℃ to reduce the Cu-organic complex in situ on the surface of the composite material.

[0021] S3: After the reaction is completed, solid-liquid separation is performed to obtain the treated water and the composite material loaded with zero-valent copper.

[0022] S4: Use a dilute hydrochloric acid solution with a concentration of 0.2-1 mol / L to elute the composite material loaded with zero-valent copper, and then rinse the composite material with water until neutral;

[0023] S5: The eluted composite material is reduced with a sodium borohydride solution with a concentration of 0.2-0.8 mol / L to regenerate the amine resin-supported palladium nanocomposite functional material;

[0024] S6: Collect the eluent obtained in step S4 to achieve copper resource recovery.

[0025] Furthermore, in step S2, the composite material is brought into full contact with the filtrate by stirring or oscillation; in step S4, the volume of the dilute acid solution is 10-50 mL / g based on the mass of the composite material, and the elution time is 10-60 minutes.

[0026] Further, the Cu-organic complex is at least one of the following Cu-organic complexes: ethylenediaminetetraacetic acid Cu-organic complex (Cu-EDTA), 1,2-cyclohexanediaminetetraacetic acid Cu-organic complex (Cu-DCTA), diethyltriaminepentaacetic acid Cu-organic complex (Cu-DTPA), ethylene glycol diethyl ether diaminetetraacetic acid Cu-organic complex (Cu-EGTA), or aminotriacetic acid Cu-organic complex (Cu-NTA).

[0027] Furthermore, the total salt concentration of the water body described in step S1 is 1 ~ 20 g / L, and the TOC content is 20 ~ 150 mg / L.

[0028] Furthermore, the concentration of Cu-organic complex in the water body described in step S1 is below 150 mg / L.

[0029] Furthermore, the reaction time in step S2 is 2 to 20 minutes.

[0030] Furthermore, the dosage of the amine resin-loaded palladium nanocomposite functional material is 0.5 g / L, and the pH value is adjusted to 3.5±0.5 during the treatment process.

[0031] Furthermore, the concentration of the dilute hydrochloric acid solution used for elution was 0.3 mol / L.

[0032] Further, step S6, which involves the recovery of copper resources, is as follows: The eluent is heated to 50℃±5℃, sodium carbonate or sodium hydroxide is added, and the pH of the system is adjusted to 3.5-4.0, so that the Cu in the eluent... 2+ All ions are precipitated as basic copper carbonate. Solid-liquid separation is performed, and the obtained solid is washed with deionized water. Then, it is dissolved in a sulfuric acid solution with a concentration of 20-25% at a temperature of 50±5℃. After the filter cake is completely dissolved, it is naturally cooled to room temperature and allowed to stand for 12-24 hours. Bright blue copper sulfate pentahydrate crystals are precipitated. The crystals are then centrifuged and dried to obtain industrial-grade copper sulfate pentahydrate.

[0033] Compared with the prior art, the present invention has the following advantages:

[0034] (1) The method of the present invention uses amine-functionalized polystyrene anion exchange resin loaded with palladium nanoparticles (Pd) as a composite functional material to realize an integrated process of "adsorption-in-situ reduction-desorption and recovery". The amine-functionalized resin loaded with palladium nanoparticles composite functional material removes Cu-organic complexes in water containing high salt and high organic matter in situ and recovers the copper element in the complexes. Based on the high efficiency of diethylenetriamine functional group itself in adsorbing and enriching Cu-organic complexes in water, the composite material uses the palladium nanoparticle catalyst embedded in the resin to directly reduce the adsorbed Cu(II) to metallic copper Cu(O) in situ. This not only has a high removal efficiency for Cu-organic complexes, but also ensures the integrity of the ligand structure of the organic complexes.

[0035] (2) The method of this invention utilizes an amino resin-supported palladium nanoparticle composite functional material to remove Cu-organic complexes from high-salt wastewater. This method is less affected by solution salinity and high organic matter concentration. In industrial wastewater, coexisting salt ions and high organic matter compete with pollutants for active sites on the adsorption material surface, thus inhibiting pollutant removal. This inhibition is particularly pronounced when salinity is very high, as the salt concentration in industrial wastewater is typically much higher than the concentration of the target pollutant. This significant difference greatly hinders pollutant removal. However, in this invention, the removal efficiency of Cu-organic complexes using an amino resin-supported palladium nanoparticle composite functional material remains approximately 90.33% when the NaCl concentration is 20 g / L. Furthermore, as the salinity increases from 0 to 20 g / L, the removal rate of Cu-EDTA by the amino resin-supported palladium nanoparticle composite functional material fluctuates within the normal range. Furthermore, when the HA concentration was 150 mg / L, the removal rate of Cu-EDTA was 65.34%. As the HA concentration further increased, the removal rate of Cu-EDTA by the amine resin-supported palladium nanoparticle composite material decreased slightly, but remained within acceptable levels. Overall, the amine resin-supported palladium nanoparticle composite material exhibits high environmental adaptability.

[0036] (3) The amino resin-loaded palladium nanocomposite functional material used in the method of the present invention can be regenerated by dilute acid and sodium borohydride solution after the reaction and recycled, reducing the processing cost. It can maintain a strong removal capacity during the recycling process. The results of the example show that the amino resin-loaded palladium nanocomposite functional material maintains a strong removal capacity for Cu-EDTA in 7 cycles. The removal efficiency of Cu-EDTA in the first five cycles can be maintained at more than 84.63%, and the sixth and seventh cycles can still be maintained at about 82.72% and 75.78%, respectively.

[0037] (4) The amino resin-loaded palladium nanocomposite functional material used in the method of the present invention loads palladium nanoparticles onto the resin carrier, which can directly act on the Cu-organic complex adsorbed on the resin in situ, realizing the direct reduction of Cu(II) to metallic copper Cu(0). This path has a clear target and high efficiency, directly attacking the core of the complex structure without completely destroying the stable organic ligand, which is theoretically more energy-efficient, and at the same time avoids the release of metal particles into the water body and causing secondary pollution.

[0038] (5) The method of the present invention uses a dilute acid solution to elute the treated composite material, so that Cu(O) dissolves and desorbs from the carrier. The eluent becomes a high-concentration copper-containing concentrate for recycling, realizing the resource recovery of copper element in Cu-complex, which meets the needs of sustainable development. Attached Figure Description

[0039] Figure 1The graph shows the relationship between the different palladium loading amounts on the amine resin-loaded palladium nanocomposite functional material and the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA.

[0040] Figure 2 The relationship between the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA by amine resin-supported palladium nanocomposite functional materials under different salt concentrations is shown in the figure.

[0041] Figure 3 The relationship between the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA by amine resin-supported palladium nanocomposite functional materials under different humic acid (HA) concentrations is shown in the figure.

[0042] Figure 4 The graph shows the relationship between the removal rate of Cu-EDTA and the EDTA formation efficiency of the amine resin-supported palladium nanocomposite functional material under different pH conditions.

[0043] Figure 5 The image shows the effect of using an amino resin-loaded palladium nanocomposite functional material to remove Cu-EDTA after 7 cycles.

[0044] Figure 6 The results show the comparison of recovery rates for different batches of copper-containing concentrate.

[0045] Figure 7 The graph shows the relationship between the removal efficiency of palladium nanocomposite functional materials supported on amine resins and the complexation of Cu with different organic ligands.

[0046] Figure 8 This study compares the removal capabilities of different amine-based resin-supported palladium nanocomposite functional materials for Cu-organic complexes. Detailed Implementation

[0047] The present invention will be further described below with reference to specific embodiments, but the scope of protection of the present invention is not limited thereto.

[0048] Example 1: The chloromethylated polystyrene resin used in this embodiment of the invention was provided by Zhejiang Zhengguang Industrial Co., Ltd., with a crosslinking density of 4%-8%, a particle size of 0.30-0.90 mm, and a pore size of 1-50 nm.

[0049] The specific preparation method of the amino resin-supported palladium nanoparticle composite functional material is as follows:

[0050] Step 1: Under room temperature (25±1℃), weigh 10g of commercially available chloromethylated polystyrene resin and soak it in 100ml of ethanol for 4 hours. After soaking, perform solid-liquid separation. Then, soak the previously treated resin in 100ml of deionized water for 4 hours, and perform solid-liquid separation again. Place the separated chloromethylated polystyrene resin in a 50℃ oven for 24 hours to dry, obtaining pretreated chloromethylated polystyrene resin.

[0051] Step 2: The chloromethylated polystyrene resin obtained in Step 1 was added to N,N-dimethylformamide swelling agent and swollen at room temperature for 18 hours. At this time, the solid-liquid ratio of the swollen resin was 10g:100ml. After swelling, the swollen chloromethylated polystyrene resin was separated, washed with ethanol, and then added to a mixed solution containing diethylenetriamine and ethanol. The solid-liquid ratio of the resin to the mixed solution was 10g:300ml, and the volume ratio of diethylenetriamine to ethanol in the mixed solution was 2:1. The above mixed system was transferred to a water bath at 65°C and heated for 18 hours for grafting reaction. After grafting, the resin was washed with ethanol and water, filtered, and dried in a constant temperature oven at 50~60°C to obtain the grafted diethylenetriamine resin.

[0052] Step 3: Weigh PdCl2 and dissolve it in 100 ml of 0.5 mol / L hydrochloric acid aqueous solution to obtain 100 ml of hydrochloric acid aqueous solution containing Pd salt. Impregnate 1 g of diethylenetriamine resin in 100 ml of hydrochloric acid aqueous solution containing Pd salt. Transfer the above mixture to a constant temperature shaker at 25±1℃ and 180 r / min for 8-10 h to obtain Pd-loaded diethylenetriamine resin.

[0053] Step 4: Solid-liquid separation. An excess of sodium borohydride solution with a concentration of 1.5% is added dropwise to the Pd-loaded resin. The Pd is reduced to its elemental form by ultrasonication under a nitrogen atmosphere and at room temperature. After washing and drying the resin, the amine resin-loaded palladium nanocomposite functional material is obtained.

[0054] According to the preparation method of Example 1, when the amount of PdCl2 used in step 3 is 0 mg, 16.70 mg, 50.10 mg, 83.50 mg, 167.00 mg, 501.00 mg and 1169 mg respectively, amine resin-loaded palladium nanocomposite functional materials with Pd loading of 0, 0.1%, 0.3%, 0.5%, 1%, 3% and 7% are obtained respectively.

[0055] Example 2: This example investigates the difference in the removal effect of different Pd loading on the amine resin-loaded palladium nanocomposite functional material on Cu-organic complexes.

[0056] This application selects 0.1 mM Cu-EDTA as the target pollutant, and its specific preparation steps are as follows:

[0057] First, prepare a 1 mmol / L Cu-EDTA stock solution: At room temperature (25±1℃), weigh 0.2496 g of copper sulfate pentahydrate and 0.3722 g of ethylenediaminetetraacetic acid disodium salt dihydrate, dissolve them in 1 L of deionized water, and transfer them to an ultrasonic bath to mix them evenly to obtain a 1 mmol / L Cu-EDTA stock solution. At this time, the molar ratio of Cu(II) to EDTA is 1:1.

[0058] To prepare a 0.1 mM Cu-EDTA target pollutant solution: at room temperature (25 ± 1 °C), weigh 90 ml of deionized water into an Erlenmeyer flask, and add 10 ml of 1 mmol / L Cu-EDTA stock solution to obtain 100 ml of a 0.1 mM Cu-EDTA target pollutant solution.

[0059] Unless otherwise stated, the initial concentration of Cu-EDTA used in all the following experiments was 0.1 mM, and the experiments used amine resin-loaded palladium nanocomposite functional materials prepared in Example 1 with Pd loadings of 0, 0.1%, 0.3%, 0.5%, 1%, 3% and 7% were selected.

[0060] Under room temperature (25±1℃), the pH of the 0.1 mM Cu-EDTA target pollutant solution was adjusted to 3.5±0.5. After filtration, a small amount of filtrate was taken and the initial concentrations of Cu-EDTA and EDTA were determined using liquid chromatography. Then, amine resin-loaded palladium nanoparticle composite material was added to the filtrate in the conical flask. The final concentration of the amine resin-loaded palladium nanoparticle composite material in the filtrate was 0.5 g / L. After thorough mixing, the conical flask was placed in a shaker and reacted for 10 min at room temperature (25±1℃) and a shaking speed of 180 r / min. The supernatant of the conical flask after the reaction was completed was taken, and the specific concentration of Cu-EDTA target pollutant after the reaction and the actual concentration of EDTA after complex-breaking and reduction were determined using liquid chromatography. By combining the concentration difference of Cu-EDTA target pollutant before and after the addition of the amine resin-loaded palladium nanoparticle composite material and the concentration difference of EDTA products, the actual removal rate of Cu-EDTA and the formation rate of EDTA after complex-breaking and reduction of Cu-EDTA can be obtained.

[0061] Following the above experimental procedure for removing Cu-EDTA target pollutants, the removal efficiency of Cu-organic complexes and the EDTA formation efficiency were compared when using amine resin-supported palladium nanocomposite functional materials prepared in Example 1 with Pd loadings of 0%, 0.1%, 0.3%, 0.5%, 1%, 3%, and 7%, respectively. (See attached figures for comparison). Figure 1.from Figure 1 It can be seen that without Pd loading, the removal rate of Cu-EDTA by diethylenetriamine resin is approximately 52.43%. With Pd loading and gradually increasing the Pd loading, the removal rate of Cu-EDTA gradually increases. When the Pd loading is 0.5 wt%, the removal efficiency of Cu-EDTA is approximately 92.14%. The removal efficiency reaches its highest point at 92.31% when the Pd loading is 1 wt%. Further increases in Pd loading lead to a decrease in Cu-EDTA removal efficiency. This may be because a significant increase in Pd loading clogs the resin pores, reducing the contact area with Cu-EDTA and thus decreasing the removal efficiency. Considering economic benefits and other factors, the optimal Pd loading is 0.5 wt%, which provides the best balance between economic benefits and removal efficiency. Therefore, in subsequent experiments, unless otherwise specified, the Pd loading on the amino resin-loaded palladium nanocomposite functional material is 0.5 wt%.

[0062] Example 3: This example investigates the removal effect of amine resin-supported palladium nanocomposite functional material on Cu-organic complexes under different salt concentrations.

[0063] Under room temperature (25±1℃) conditions, using the same 0.1mM Cu-EDTA target pollutant solution (pH adjusted to 3.5±0.5 and filtered as in Example 2), NaCl was added to the target pollutant solution at final concentrations of 0, 1, 5, 10, 15, and 20 g / L to investigate the removal of Cu-EDTA and the formation of EDTA after complex disruption and reduction under different salinities.

[0064] The removal process of Cu-EDTA target pollutant was repeated according to the steps of Example 2, with the only differences being the following two points: ① The amine resin-supported palladium nanocomposite functional material with a Pd loading of 0.5% prepared in Example 1 was used for the test experiment; ② The target pollutant solution was a 0.1 mM Cu-EDTA target pollutant solution with different salt concentrations prepared in Example 3.

[0065] Example 3: When amine resin-supported palladium nanocomposite functional materials were used to treat 0.1 mM Cu-EDTA target pollutant solutions with different salt concentrations, the comparison results of the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA are shown in the figure. Figure 2 .

[0066] from Figure 2It can be seen that the catalytic reduction ability of the amine resin-supported palladium nanoparticle composite material for Cu-EDTA is not inhibited with increasing NaCl concentration. When the NaCl concentration is 20 g / L, the removal efficiency of Cu-EDTA is approximately 90.33%, maintaining a high treatment level. Furthermore, when the salinity increases from 0 to 20 g / L, the apparent rate constant for Cu-EDTA removal by the amine resin-supported palladium nanoparticle composite material fluctuates within the normal range. Therefore, it can be inferred that the presence of NaCl does not interfere with Cu-EDTA removal, which may be due to the nano-size effect and high activity of the amine resin-supported palladium nanoparticle composite material.

[0067] Example 4: This example demonstrates the treatment effect of amine resin-supported palladium nanocomposite functional material on different concentrations of humic acid (HA), and is used to explore the influence of high organic content on the removal of Cu-organic complexes by amine resin-supported palladium nanocomposite functional material.

[0068] At room temperature (25±1℃), the pH of the 0.1mM Cu-EDTA target pollutant solution was adjusted to 3.5±0.5. NaCl with a final concentration of 15 g / L was added to simulate industrial wastewater. After filtration, HA with final concentrations of 0, 25, 50, 75, 100, and 150 mg / L was added to the target pollutant solution to investigate the removal of Cu-EDTA and the formation of EDTA after complex disruption and reduction at different HA concentrations.

[0069] The removal process of Cu-EDTA target pollutant was repeated according to the steps of Example 2, with the only differences being the following two points: ① The amine resin-loaded palladium nanocomposite functional material with a Pd loading of 0.5% prepared in Example 1 was used for the test experiment; ② The target pollutant solution was a 0.1 mM Cu-EDTA target pollutant solution with different HA concentrations prepared in Example 4.

[0070] Example 4: When amine resin-supported palladium nanocomposite functional materials were used to treat 0.1 mM Cu-EDTA target pollutant solutions with different HA concentrations, the comparison results of the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA are shown in the figure. Figure 3 .

[0071] like Figure 3As shown, with the increase of HA concentration, the removal efficiency of the amine resin-supported palladium nanocomposite material was slightly inhibited and decreased. However, when the HA concentration was 150 mg / L, the removal efficiency of the amine resin-supported palladium nanocomposite material for Cu-EDTA was still about 65.34%. At this time, the HA concentration was much higher than the initial dosage concentration of Cu-EDTA of 0.1 mM (35.38 mg / L), but there was still a good treatment level. This indicates that the amine resin-supported palladium nanocomposite material has good adaptability to water bodies with high organic matter concentrations.

[0072] Example 5: This example demonstrates the removal effect of amine resin-supported palladium nanoparticle composite functional material on Cu-EDTA under different pH conditions.

[0073] pH is an important parameter affecting the removal process. Since Cu-organic complexes exist in a wide pH range, 2 to 11 were selected as the background pH value. Under the conditions of room temperature (25±1℃), 0.1 mM Cu-EDTA target pollutant without pH adjustment was prepared using the same method as in Example 2. NaCl with a final concentration of 15 g / L was added to simulate industrial wastewater. The pH of these Cu-EDTA target pollutant solutions was adjusted to 2, 3, 4, 5, 7, 9 and 11 respectively. The filtrate was obtained by filtration. The removal of Cu-EDTA and the formation of EDTA after complex disruption and reduction were investigated under different pH conditions.

[0074] The removal process of Cu-EDTA target pollutant was repeated according to the steps of Example 2, with the only differences being the following two points: ① The amine resin-loaded palladium nanocomposite functional material with a Pd loading of 0.5% prepared in Example 1 was used for the test experiment; ② The target pollutant solution was a 0.1mM Cu-EDTA target pollutant solution with different pH values ​​prepared in Example 5.

[0075] Example 5: When amine resin-supported palladium nanocomposite functional materials were used to treat 0.1 mM Cu-EDTA target pollutant solutions at different pH values, the comparison results of the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA are shown in the figure. Figure 4 .

[0076] like Figure 4As shown, the in-situ reduction and removal capacity of the amine resin-supported palladium nanoparticle composite material remains good within a pH range of 2 to 6. However, the removal rate is inhibited when the water pH changes from acidic to alkaline. This may be because Cu-organic complexes are more stable and difficult to remove under alkaline conditions. For example, at pH 2 (a strongly acidic environment), the removal efficiency of the amine resin-supported palladium nanoparticle composite material for Cu-EDTA is approximately 91.90%, which is relatively high. However, at pH 11 (a strongly alkaline environment), the removal efficiency is only about 19.19%, showing a significant decrease. In summary, the amine resin-supported palladium nanoparticle composite material is suitable for acidic pH ranges of 2 to 6, but less suitable for alkaline water bodies.

[0077] Example 6: Effect of removing Cu-EDTA from 7 cycles using amine resin-loaded palladium nanocomposite functional material.

[0078] Considering the cost-effectiveness of practical engineering applications, the feasibility of recycling amine resin-supported palladium nanocomposite functional materials was explored.

[0079] Under room temperature (25±1℃), the pH of a 0.1 mM Cu-EDTA target pollutant solution was adjusted to 3.5±0.5. NaCl with a final concentration of 15 g / L was added to simulate industrial wastewater. After filtration, 50 ml of the filtrate was placed in a 150 mL Erlenmeyer flask. 25 mg of the amine resin-loaded palladium nanocomposite material prepared in Example 1 with a Pd loading of 0.5% was added to the flask. The final concentration of the amine resin-loaded palladium nanocomposite material in the filtrate was 0.5 g / L. After mixing thoroughly, the flask was placed in a shaker and reacted at room temperature for 10 min at 25±1℃ and a shaking speed of 180 r / min. After the reaction, the actual removal rate of Cu-EDTA and the formation rate of EDTA after Cu-EDTA complex lysis and reduction were determined using the same method as in Example 2. Solid-liquid separation was performed on the system after the reaction to obtain the amine resin-loaded palladium nanocomposite material loaded with zero-valent copper. At room temperature (25±1℃), the amine resin-loaded palladium nanoparticle composite material with zero-valent copper was mixed with 0.3 mol / L dilute hydrochloric acid eluent in a 50 mL Erlenmeyer flask. The solid-liquid ratio of the material to the eluent was 1 g: 20 mL. The flask was placed in a constant-temperature shaker at 25±1℃ and 180 r / min for 30 min. After elution, solid-liquid separation yielded the eluted amine resin-loaded palladium nanoparticle composite material. Subsequently, the eluted amine resin-loaded palladium nanoparticle composite material was regenerated using 0.5 mol / L sodium borohydride solution. The regenerated amine resin-loaded palladium nanoparticle composite material was placed in a 150 mL Erlenmeyer flask, and 50 mL of contaminant solution was added again. This process was repeated 7 times.

[0080] Example 6: Comparative results of removing Cu-EDTA using amine resin-supported palladium nanocomposite functional materials after 7 cycles are shown in [the original text]. Figure 5 ,from Figure 5 It can be seen that the amino resin-supported palladium nanocomposite functional material maintains a strong removal capacity for Cu-EDTA throughout the 7 cycles. The removal efficiency of Cu-EDTA can be maintained at more than 84.63% in the first five cycles, and can still be maintained at around 82.72% and 75.78% in the sixth and seventh cycles, respectively.

[0081] Example 6: The copper recovery process for the copper-containing concentrate obtained by eluting the amine resin-supported palladium nanoparticle composite material loaded with zero-valent copper using 0.3 mol / L dilute hydrochloric acid solution during the first five cycles includes the following steps:

[0082] Step 1: Under room temperature (25±1℃), the system after the reaction was completed was subjected to solid-liquid separation to obtain the treated water and the composite material loaded with zero-valent copper. The composite material loaded with zero-valent copper was eluted with 0.3 mol / L dilute hydrochloric acid solution. The solid-liquid ratio of the composite material to the eluent was 1 g: 20 mL. The mixture was placed in a constant temperature shaker at 25±1℃ and 180 r / min for 30 min. After elution, the solid and liquid were separated to obtain the eluent containing Cu(II). The eluent was collected. At this time, the pH of the eluent was 1-1.5.

[0083] Step 2: Heat the eluent to 50°C, add industrial-grade sodium carbonate or sodium hydroxide, and adjust the pH of the system to 3.5-4.0 so that all Cu(II) in the eluent precipitates as basic copper carbonate powder.

[0084] Step 3: At room temperature (25±1℃), the precipitation system from Step 2 is filtered using a plate and frame filter and a filter bag. The filter cake is rinsed several times with deionized water at 50±5℃ to remove Na. + Add soluble salts until the conductivity of the eluent is less than 2 ms / cm.

[0085] Step 4: At room temperature (25±1℃), dissolve the filter cake washed in Step 3 in a 22.5% sulfuric acid solution at 50±5℃. The mass of the sulfuric acid solution should be 1.2-1.3 times that of the filter cake. After the filter cake is completely dissolved, allow it to cool naturally to room temperature. After 18 hours, bright blue copper sulfate pentahydrate crystals will precipitate. Centrifuge the crystals and dry them in an oven at 60℃ to obtain industrial-grade copper sulfate pentahydrate.

[0086] The recovery rate of copper in the copper-containing concentrate can be obtained by comparing the Cu(II) content in the eluent from step 1 with the Cu(II) content in copper sulfate pentahydrate from step 4. The comparison results of the recovery rates of different batches of copper-containing concentrate are shown in [the table below]. Figure 8 .

[0087] Example 7: This example investigates the removal effect of amine resin-supported palladium nanocomposite functional material on different Cu-organic complexes.

[0088] Natural water bodies and industrial wastewater contain a large number of different ligands. This embodiment studies the removal of different Cu-organic complexes by an amino resin-supported palladium nanocomposite material. Cu-organic complexes formed by common organic ligands and Cu were selected, and the preparation method was the same as that used in Example 2 for preparing the 0.1 mM Cu-EDTA target pollutant solution. The initial concentration of the Cu-organic complex was selected as 0.1 mM.

[0089] Example 7 repeats the steps of Example 2 for the removal of different Cu-organic complexes, with the only differences being the following two points: ① The amine resin-supported palladium nanocomposite functional material with a Pd loading of 0.5% prepared in Example 1 is used for the test experiment; ② The target pollutant solution is a 0.1 mM solution of different Cu-organic complexes prepared in Example 7.

[0090] Example 7: The comparison of the removal efficiency of Cu-organic complexes by the amine resin-supported palladium nanocomposite functional material when treating Cu-organic complex solutions of different 0.1 mM concentrations is shown in the figure. Figure 6 .

[0091] from Figure 6 As can be seen, the amino resin-supported palladium nanocomposite functional material exhibits good removal efficiency for copper in various complex states, especially for carboxylic acids with strong binding ability (such as EGTA), maintaining a high removal efficiency of 93.49%. Simultaneously, it maintains a very high removal efficiency for various Cu-organic complexes, with removal efficiencies all above approximately 84.38%, indicating that a large amount of various ligands can be removed.

[0092] Example 8: This example investigates the differences in the removal of Cu-organic complexes by different amine resin-supported palladium nanocomposite functional materials.

[0093] Example 8: Preparation method of palladium nanoparticle composite functional material loaded with amine resin with Pd loading of 0.5% was repeated in Example 1, except that "in step 2, diethylenetriamine was replaced with the same volume of ethylenediamine, diethylenetriamine, triethylenetetramine or tetraethylenepentamine, and in step 3, the amount of PdCl2 used was 83.50 mg", and the other conditions remained unchanged, and finally, palladium nanoparticle composite functional materials loaded with different amine resins with Pd loading of 0.5% were obtained.

[0094] Example 8 repeats the steps of Example 2 in the Cu-EDTA target pollutant removal experiment, except that: different amine resin-loaded palladium nanocomposite functional materials with a Pd loading of 0.5% prepared in Example 8 are used for the test experiment.

[0095] Example 8 compares the removal efficiency of Cu-organic complexes and the formation efficiency of EDTA when using different amine resins loaded with 0.5% Pd in ​​palladium nanoparticle composite functional materials. (See [link to Example 8]). Figure 7 .from Figure 7It can be seen that different amine resin-supported palladium nanocomposite functional materials have different removal effects on Cu-organic complexes of the same concentration. However, comparing the removal rates of Cu-EDTA by these amine resin-supported palladium nanocomposite functional materials, it can be found that the diethylenetriamine resin substrate used in the experiment has the highest removal rate of Cu-organic complexes, about 92.14%, while the ethylenediamine resin substrate has the lowest removal rate, about 45.96%. The comparison leads to the conclusion that when the number of amines in the polyamine group compound is ≥3, the removal rate of Cu-organic complexes is higher.

[0096] The contents described in this specification are merely an enumeration of the implementation forms of the inventive concept, and the scope of protection of this invention should not be regarded as limited to the specific forms described in the embodiments.

Claims

1. The application of an amine resin-supported palladium nanocomposite functional material in the efficient removal of Cu-organic complexes and copper resource recovery from high-salt, high-organic-content wastewater, characterized in that... The matrix of the amine resin-loaded palladium nanocomposite functional material is a chloromethylated polystyrene resin grafted with polyamine groups. The chloromethylated polystyrene resin has a crosslinking degree of 4%-8%, a particle size of 0.30-0.90 mm, and a pore size of 1-50 nm. The polyamine group compound is a compound including two primary amine groups and at least one secondary amine group. The matrix surface has a uniformly distributed porous structure, and palladium nanoparticles are loaded in the pores. The loading rate of palladium nanoparticles in the composite material is 0.25%-5% by mass percentage.

2. The application as described in claim 1, characterized in that, The polyamine compound is diethylenetriamine, and the loading rate of palladium nanoparticles in the composite material is 0.5%-1% by mass.

3. The application as described in claim 1, characterized in that, A method for preparing amine resin-supported palladium nanoparticle composite functional materials includes the following steps: Step 1: After soaking the chloromethylated polystyrene resin in ethanol and deionized water in sequence, it is added to N,N-dimethylformamide swelling agent and subjected to swelling treatment at room temperature for 12-24 h. After solid-liquid separation, the swollen chloromethylated polystyrene resin is obtained. Step 2: The chloromethylated polystyrene resin pretreated in Step 1 is grafted with the polyamine group compound to obtain an amino-functionalized resin. Step 3: Impregnate the amino-functionalized resin in an aqueous hydrochloric acid solution containing Pd salt. The concentration of the aqueous hydrochloric acid solution is 0.4-0.8 mol / L. The loading of Pd is completed under shaking. Step 4: Solid-liquid separation. An excess sodium borohydride solution is added dropwise to the Pd-loaded resin. The Pd is reduced to its elemental form by ultrasonication under a nitrogen atmosphere and at room temperature. The resin is then washed and dried to obtain the amine resin-loaded palladium nanocomposite functional material.

4. The application as described in claim 3, characterized in that, In step 2, the chloromethylated polystyrene resin is added to a polyamine group compound-ethanol mixed solution at a solid-liquid ratio of 10g:200-400mL, wherein the volume ratio of the polyamine group compound to ethanol is 1.5-2.5:

1. The grafting reaction is carried out at a temperature of 60-70℃ for 12-24 hours, and then filtered, washed and dried sequentially to obtain the amine functionalized resin.

5. The application as described in claim 1, characterized in that, Includes the following steps: S1: Adjust the pH of the high-salt, high-organic-matter water containing Cu-organic complexes to 2.0-6.0, and then filter to obtain the filtrate; S2: Add the amine resin-supported palladium nanocomposite functional material to the filtrate obtained in step S1, and react at 20-40°C to reduce the Cu-organic complex on the surface of the composite material in situ. S3: After the reaction is completed, solid-liquid separation is performed to obtain the treated water and the composite material loaded with zero-valent copper. S4: Use a dilute hydrochloric acid solution with a concentration of 0.2-1 mol / L to elute the composite material loaded with zero-valent copper, and then rinse the composite material with water until neutral; S5: The eluted composite material is reduced with sodium borohydride solution to regenerate the amine resin-loaded palladium nanocomposite functional material. S6: Collect the eluent obtained in step S4 to achieve copper resource recovery.

6. The application as described in claim 5, characterized in that, In step S2, the composite material is brought into full contact with the filtrate by stirring or oscillation; in step S4, the volume of the dilute acid solution is 10-50 mL / g based on the mass of the composite material, and the elution time is 10-60 minutes.

7. The application as described in claim 5, characterized in that, The Cu-organic complex is at least one of the following Cu-organic complexes: Cu-EDTA, Cu-DCTA, Cu-DTPA, Cu-EGTA, Cu-NTA; The total salt concentration of the water body in step S1 is 1 ~ 20 g / L, the TOC content is 20 ~ 150 mg / L, and the concentration of Cu-organic complex in the water body in step S1 is below 150 mg / L.

8. The application as described in claim 5, characterized in that, The reaction time in step S2 is 2 to 20 minutes.

9. The application as described in claim 5, characterized in that, Step S6, the copper resource recovery process, is as follows: The eluent is heated to 50℃±5℃, sodium carbonate or sodium hydroxide is added, and the pH of the system is adjusted to 3.5-4.0 to allow the Cu in the eluent to be concentrated. 2+ All ions are precipitated as basic copper carbonate. Solid-liquid separation is performed, and the obtained solid is washed with deionized water. Then, it is dissolved in a sulfuric acid solution with a concentration of 20-25% at a temperature of 50±5℃. After the filter cake is completely dissolved, it is naturally cooled to room temperature and allowed to stand for 12-24 hours. Bright blue copper sulfate pentahydrate crystals are precipitated. The crystals are then centrifuged and dried to obtain industrial-grade copper sulfate pentahydrate.

Images