Copper slag-based amorphous composite and application thereof in organic arsenic removal

Abstract

The application discloses a copper residue-based amorphous composite material, which is prepared by the following steps: crushing and screening dried copper residue, calcining the screened copper residue at 450-550 DEG C, mixing the calcined copper residue, manganese salt and water, adding potassium permanganate solution into the mixture, uniformly mixing the mixture, heating the mixture in a water bath at 45-55 DEG C, and separating the reaction product into solid and liquid, and then washing, drying and grinding the solid to obtain the copper residue-based amorphous composite material; the material has the advantages of high specific surface area, many reaction active sites, good oxidation and adsorption performance, high metal atom utilization rate and stable structure, and can be widely applied to oxidizing and adsorbing organic arsenic; and the adsorption removal effect is good; and the application realizes resource utilization of solid waste and has great application prospect in the field of environment.

Description

Technical Field

[0001] This invention belongs to the field of solid waste secondary utilization technology, specifically relating to a method for preparing a copper slag-based amorphous composite material and its application in the removal of organic arsenic. Background Technology

[0002] Organic arsenic, as a class of persistent organometallic pollutants, is widely present in environmental media, typically in the form of stable complexes formed between organic ligands and inorganic arsenic species. p-Aminobenzoic acid (p-ASA) is a representative aromatic organic arsenic compound, widely used as a feed additive in intensive livestock farming due to its significant effects in controlling livestock diseases and promoting growth performance. However, because animals have extremely limited capacity to assimilate these compounds, most ingested p-ASA is excreted in its original form through animal urine and feces without metabolic transformation, subsequently entering the soil and aquatic environment. Although p-ASA itself has relatively low acute toxicity, it possesses high water solubility and environmental mobility, enabling it to migrate and diffuse in soil-water systems. More importantly, under natural conditions, p-ASA can be gradually degraded or transformed into significantly more toxic inorganic arsenic forms (such as As(III) and As(V)) and other organic arsenic intermediates through microbial action, photolysis, or abiotic reactions with other environmental media. These transformation products not only have higher bioavailability and toxicity, but may also accumulate through the food chain, posing a potential and persistent threat to ecosystem function, groundwater security, and public health.

[0003] Currently, catalytic materials used for the removal of organic arsenic mainly include iron-based, titanium-based, and manganese-based metal oxides, metal-organic frameworks (MOFs), biochar-based composite materials, and photocatalytic semiconductor materials. However, existing catalytic materials still have many shortcomings in practical applications: metal oxides have poor selectivity for organic arsenic, are easily affected by coexisting ions in water, have insufficient structural stability, and pose a risk of active component dissolution; metal-organic frameworks have poor hydrothermal stability and high preparation costs, making it difficult to achieve large-scale production and engineering applications; biochar-based catalytic materials have a limited number of active sites, and their recycling performance and long-term operational stability need to be improved; photocatalytic materials generally suffer from narrow visible light response range, high photogenerated carrier recombination rate, low catalytic efficiency, difficulty in solid-liquid separation, and potential secondary pollution. Furthermore, most catalytic systems have weak adaptability to complex aquatic environments, making it difficult to simultaneously achieve efficient degradation of organic arsenic, controllable conversion of intermediate products, and deep removal of total arsenic, thus limiting the industrial application of catalytic technology in the field of organic arsenic pollution control.

[0004] Copper slag is a solid waste residue formed during the smelting of copper alloys. It is mainly composed of Fe3O4, Fe2SiO4, Al2O3, CaO, etc. The overall utilization rate of copper slag is low, and most of it is still stockpiled, occupying a large amount of land and causing environmental pollution. Copper slag contains a large amount of ferrous silicate, which has cementing properties after alkali activation. In addition, copper slag also contains a large amount of magnetite, and the prepared products are magnetic, which facilitates the separation and recovery of catalysts. Summary of the Invention

[0005] This invention provides a copper slag-based amorphous composite material, which is prepared by crushing and sieving dried copper slag, calcining it at 450-550℃, mixing the calcined copper slag, manganese salt, and water, adding potassium permanganate solution dropwise to the mixture, mixing thoroughly, heating in a water bath at 45-55℃, separating the solid and liquid products, and washing, drying, and grinding the solid to obtain the final product. This material has advantages such as high specific surface area, many reactive sites, good oxidation and adsorption performance, high metal atom utilization rate, and stable structure. The copper slag-based amorphous composite material of this invention can oxidize organic arsenic to less toxic As(V), and then adsorb As(V), thereby achieving the removal of organic arsenic.

[0006] The objective of this invention is achieved through the following technical solution: 1. Dry the copper slag at a constant temperature of 50-65℃ for 36-48 hours, ball mill for 2-3 hours, and then sieve to obtain copper slag powder. Place the copper slag powder in a crucible and place it in a tube furnace at 450-550℃ for 2-4 hours. Grind it to obtain roasted copper slag. 2. Mix manganese salt, calcined copper slag from step 1, and water evenly to obtain a mixture. Add potassium permanganate solution dropwise to the mixture and heat in a water bath at 45-55℃ for 24 hours. Separate the solid and liquid products of the reaction. Wash, dry, and grind the solid to obtain copper slag-based amorphous composite material A-CSM. The mass ratio of calcined copper slag to manganese salt is 0.8-1.7:1, and the mass ratio of potassium permanganate to calcined copper slag is 0.3-0.8:1.

[0007] 3. The copper slag-based amorphous composite material A-CSM was applied to the oxidation-adsorption of p-aminobenzoarsine. The experimental results showed that the removal rate of p-aminobenzoarsine by the copper slag-based amorphous composite material A-CSM was over 97%.

[0008] The present invention has the following advantages over the prior art: (1) The present invention uses industrial solid waste copper slag as raw material. After simple roasting treatment, the moisture and some impurities in the solid waste copper slag are removed. The process is simple and the cost is low. (2) This invention employs a simple hydrothermal synthesis to successfully prepare an amorphous copper slag-based amorphous composite material with advantages such as high specific surface area, numerous reactive sites, good oxidation adsorption performance, high metal atom utilization rate, and stable structure. Furthermore, the preparation method is simple to operate, has a high yield, and can significantly improve the specific surface area of ​​the catalyst, thereby enhancing its adsorption performance. Due to its short-range ordered and long-range disordered structural characteristics, the amorphous copper slag-based amorphous composite material exhibits superior pollutant removal performance: its randomly oriented chemical bonds and unstable lattice oxygen enhance oxygen mobility, and abundant surface defects (such as oxygen vacancies) enhance chemical adsorption and molecular oxygen activation capabilities. Simultaneously, the defect structure alters the pore distribution, increases porosity and specific surface area, and exposes more active interfaces, further improving adsorption performance. At the same time, the preparation method of this invention also features simple process, convenient operation, readily available raw materials, low cost, and ease of industrial production, making it a promising candidate for application, especially in the field of environmental oxidation adsorption. (3) The copper slag-based amorphous composite material A-CSM of the present invention can be uniformly mixed with wastewater containing P-ASA, which can oxidize P-ASA into less toxic As(V), and then adsorb As(V), effectively reducing the toxicity of wastewater; it has a good removal effect on wastewater containing P-ASA in daily life, and has a good development prospect in the field of treating heavy metal toxic wastewater. Attached Figure Description

[0009] Figure 1 The XRD patterns are of calcined copper slag CS-Fe, copper slag-based amorphous composite material A-CSM, and Comparative Example 3 A-MnO2. Figure 2 The XRD patterns are of the calcined copper slag CS-Fe, copper slag-based amorphous composite material A-CSM, catalyst MnO2 of Comparative Example 1, catalyst CSM of Comparative Example 2, and catalyst A-MnO2 of Comparative Example 3. Figure 3 Here is a SEM image of CS-Fe in roasted copper slag from Example 1; Figure 4 Here is a SEM image of the copper slag-based amorphous composite material A-CSM from Example 1; Figure 5 Here is a SEM image of the catalyst MnO2 in Comparative Example 1; Figure 6 Here is a SEM image of the catalyst CSM in Comparative Example 2; Figure 7 Here is a SEM image of catalyst A-MnO2 from Comparative Example 3; Figure 8 The graphs show the time-degradation efficiency of the catalysts in Example 1 and Comparative Examples 1-4 when they degraded P-ASA solution under oscillating conditions. Figure 9This is a fitting graph of the degradation rate constant of the catalyst in Example 1 when it degrades P-ASA solution under isothermal oscillation conditions; Figure 10 This is a graph showing the change in the concentration of organic arsenic species during the degradation of p-ASA by the catalyst under isothermal oscillation conditions in Example 1. Figure 11 The graph shows the time-degradation efficiency of the catalyst in Example 1 when it was cyclically degraded into p-ASA solution 5 times under isothermal oscillation conditions. Detailed Implementation

[0010] The following examples further illustrate the content of the present invention, but these examples do not limit the scope of protection of the present invention. Unless otherwise specified, the methods in the examples are conventional methods, and the reagents used are commercially available reagents unless otherwise specified. The main components of the copper slag used in the following examples are Fe2O3 73.79%, SiO2 10.47%, Al2O3 1.32%, CaO 3.02%, and ZnO 3.78%; Example 1: Preparation of copper slag-based amorphous iron-manganese composite material using copper slag 1. Copper slag was dried at 60℃ for 40 hours, ball-milled for 2 hours, and then passed through a 180-mesh sieve to obtain copper slag powder. The copper slag powder was placed in a crucible and calcined in a tube furnace at 500℃ for 3 hours. After grinding, black calcined copper slag CS-Fe was obtained. The XRD pattern of calcined copper slag CS-Fe is shown below. Figure 1 , 2 It can be seen that the diffraction peaks of the CS-Fe catalyst at 32.86°, 34.88°, 43.2°, and 62.7° correspond to the (220), (311), (400), and (440) crystal planes, respectively, which are in good agreement with the standard peaks of magnetite (Fe3O4) (JCPDS 19-0629). The diffraction peaks at 24.98°, 31.54°, 35.46°, 37.46°, 51.38°, and 70.54° correspond to the (111), (031), (211), (140), (222), and (143) crystal planes, respectively, which are in good agreement with the standard peaks of fir olivine (Fe2SiO4) (JCPDS 34-0178), indicating that the iron in the catalyst exists in the form of magnetite and fir olivine. The SEM image of CS-Fe is shown below. Figure 3 The CS-Fe material exhibits good structural compactness, smooth and uniform surface morphology, and typical blocky arrangement with no obvious pores or structural defects observed. 2. Take 0.7g of manganese sulfate monohydrate and 0.6g of roasted copper slag CS-Fe and place them in 50mL of deionized water, denoted as mixture A. Dissolve 0.43g of potassium permanganate in 50mL of deionized water to prepare a potassium permanganate solution. Add the potassium permanganate solution dropwise to mixture A and mix thoroughly. Place the mixture in a constant temperature water bath and keep it at 50℃ for 24h. After natural cooling, filter the solution. Wash the solid five times with water and dry it at 60℃ for 12h. Grind it in a mortar and pestle to obtain the copper slag-based amorphous composite material A-CSM. The SEM image of A-CSM is shown below. Figure 4 As can be seen from the figure, the entire surface of the calcined copper slag CS-Fe is tightly coated with MnO2 nanospheres. Compared with the calcined copper slag CS-Fe, the surface of the copper slag-based material becomes rough and forms a network structure. XRD pattern of copper slag-based amorphous composite material A-CSM is shown below. Figure 1 , 2 The figure shows that A-CSM exhibits relatively broad and weak diffraction peaks at 2θ = 35°, 43° and 65°, respectively, indicating that the crystal structure of the calcined copper slag CS-Fe was transformed from a crystalline phase to an amorphous phase by loading A-MnO2.

[0011] Example 2: The method in this example is the same as in Example 1, except that 0.35g of manganese sulfate monohydrate and 0.6g of roasted copper slag CS-Fe are dissolved in deionized water, and 0.215g of potassium permanganate is dissolved in 50mL of deionized water.

[0012] Example 3: The method in this example is the same as in Example 1, except that 0.42g of manganese sulfate monohydrate and 0.6g of roasted copper slag CS-Fe are dissolved in deionized water, and 0.258g of potassium permanganate is dissolved in 50mL of deionized water.

[0013] Example 4: The method in this example is the same as in Example 1, except that 0.49g of manganese sulfate monohydrate and 0.6g of roasted copper slag CS-Fe are dissolved in deionized water, and 0.301g of potassium permanganate is dissolved in 50mL of deionized water.

[0014] Example 5: The method in this example is the same as in Example 1, except that 0.56g of manganese sulfate monohydrate and 0.6g of roasted copper slag CS-Fe are dissolved in deionized water, and 0.344g of potassium permanganate is dissolved in 50mL of deionized water.

[0015] Example 6: The method in this example is the same as in Example 1, except that 0.63g of manganese sulfate monohydrate and 0.6g of roasted copper slag CS-Fe are dissolved in deionized water, and 0.386g of potassium permanganate is dissolved in 50mL of deionized water.

[0016] Comparative Example 1: Preparation of crystalline manganese dioxide catalyst (MnO2) Dissolve 0.948 g of potassium permanganate in 35 mL of deionized water, then add 0.169 g of manganese sulfate monohydrate, stir for 30 minutes, and place the mixture in a high-pressure reactor. Maintain the temperature at 160 °C for 12 hours. After natural cooling, filter the solution. Wash the solid with water and anhydrous ethanol until the sample is neutral. Dry at 60 °C for 4 hours and grind in a mortar to obtain the MnO2 catalyst. Its XRD pattern is shown below. Figure 2 As can be seen from the figure, MnO2 has obvious characteristic peaks at 2θ = 12 ° (001), 24.8 ° (002), 36.4 ° (100), and 65.6 ° (110), which are consistent with the peaks of δ-MnO2 (JCPDS 43-1456) standard card, indicating the successful synthesis of δ-MnO2; the SEM image of MnO2 is shown in [image missing]. Figure 5 As can be seen from the figure, MnO2 is in the form of "flower-like spheres", with a relatively large particle size, uniform shape, and agglomeration.

[0017] Comparative Example 2: Preparation of Crystalline Iron-Manganese Catalyst (CSM) Dissolve 0.948 g of potassium permanganate and 0.145 g of calcined copper slag CS-Fe in 35 mL of deionized water, then add 0.169 g of manganese sulfate monohydrate, stir for 30 minutes, and place the mixture in a high-pressure reactor. Maintain the temperature at 160 °C for 12 h. After natural cooling, filter the solution, wash the solid with water and anhydrous ethanol until the sample is neutral, dry at 60 °C for 4 h, and grind in a mortar to obtain the crystalline iron-manganese composite (CSM) catalyst. Its XRD pattern is shown below. Figure 2 As shown in the figure, the diffraction peak positions (2θ = 12.2 °, 24 °, 37.1 °, and 66 °) of CS-Fe loaded with δ-MnO2 are consistent with the standard diffraction pattern of δ-MnO2, proving the successful composite of the two materials. The SEM image is shown below. Figure 6 As can be seen from the figure, the entire surface of CS-Fe is tightly coated with MnO2 nanospheres; Comparative Example 3: Preparation of amorphous manganese dioxide catalyst (A-MnO2) Dissolve 0.845 g of manganese sulfate monohydrate in 50 mL of deionized water, labeled as solution A. Dissolve 0.527 g of potassium permanganate in 50 mL of deionized water, labeled as solution B. Add solution A dropwise to solution B to obtain a homogeneous mixture. Place this mixture in a constant temperature water bath and maintain the temperature at 50°C for 12 hours. After natural cooling, filter the mixture. Wash the solid five times with water and dry it at 60°C for 12 hours. Grind the solid in a mortar and pestle to obtain an amorphous manganese dioxide catalyst. The SEM image of the amorphous manganese dioxide catalyst is shown below. Figure 7 As can be seen from the figure, the product is a small-diameter nanosphere with several radiating scales on its exterior. These scales can be used to magnify the surface condition. Figure 2The XRD pattern shows that the A-MnO2 synthesized at low temperature exhibits only very weak diffraction peaks, indicating that it has an amorphous structure.

[0018] Comparative Example 4: Preparation of PS from Calcinated Phosphorus Slag Phosphorus slag was dried at a constant temperature of 60℃ for 40 hours, ball-milled for 2 hours, and then passed through a 180-mesh sieve to obtain phosphorus slag powder. The phosphorus slag powder was placed in a crucible and calcined in a tube furnace at 500℃ for 3 hours, and then ground to obtain calcined phosphorus slag PS.

[0019] Example 7: Application of the catalysts in Examples 1-6 and Comparative Examples 1-4 in the treatment of P-ASA wastewater 1. Weigh out 50 mg each of the catalysts A-CSM (Examples 1-6), MnO2 (Comparative Example 1), CSM (Comparative Example 2), A-MnO2 (Comparative Example 3), and PS (Comparative Example 4), and place them in 50 mL of a 30 mg / L P-ASA solution. Add 198 μL of H2O2 and adjust the initial pH of the reaction solution to 3 ± 0.1 using 0.1 M NaOH and 0.1 M HCl solutions. Then, place them in a constant temperature shaker and shake continuously at 180 rpm for 60 minutes at 25 °C. Take 5 mL of P-ASA solution at 15 min, 30 min, 45 min, and 60 min, respectively, and use high performance liquid chromatography (HPLC) to detect the concentration of residual P-ASA in the solution. Calculate the degradation efficiency of different catalysts on P-ASA solution under the same time conditions.

[0020] See results Figure 8 The A-CSM composite material in Example 1 exhibited significant performance advantages, with a degradation rate of 98.48% for P-ASA under oscillation conditions; this was higher than that of the catalysts in Comparative Examples 1-4, indicating that the A-CSM catalyst has highly efficient oxidation and adsorption performance.

[0021] The degradation efficiency of the catalyst in Example 2 was 97.37% after 60 min, the degradation efficiency of the catalyst in Example 3 was 97.62% after 60 min, the degradation efficiency of the catalyst in Example 4 was 97.99% after 60 min, the degradation efficiency of the catalyst in Example 5 was 96.98% after 60 min, and the degradation efficiency of the catalyst in Example 6 was 97.88% after 60 min. The degradation rates of Examples 2-6 were also higher than those of the catalysts in Comparative Examples 1-4. The fitting results of the degradation rate constant are shown in Figure 9 As can be seen from the figure, the degradation rate of P-ASA by catalyst A-CSM in Example 1 is several times that of other types of catalysts, indicating that catalyst A-CSM in Example 1 has excellent catalytic performance.

[0022] Changes in organic arsenic concentrations are shown in Figure 10As can be seen from the figure, P-ASA rapidly degrades and is converted into As (V) in the initial stage of the reaction (0~15min). The concentration of As (V) increases and then slowly decreases, indicating that the catalyst can realize the conversion of organic arsenic to inorganic arsenic and the subsequent effective removal of arsenic.

[0023] The catalyst from Example 1 used in Example 7 was collected, washed and dried with deionized water, and then recycled for treating P-ASA wastewater according to the method in Example 7. After four cycles, the recycling performance was as follows: Figure 11 The degradation efficiency was still 89.01% in the fifth time, demonstrating excellent structural stability and catalytic durability, which fully illustrates that the catalyst has good reusability.

Claims

1. A copper slag-based amorphous composite material, characterized in that: After the dried copper slag is crushed and sieved, it is roasted at 450-550℃. The roasted copper slag, manganese salt and water are mixed, and potassium permanganate solution is added dropwise to the mixture. After mixing, the mixture is heated in a water bath at 45-55℃. The reaction product is separated into solid and liquid. The solid is washed, dried and ground to obtain the final product.

2. The copper slag-based amorphous composite material according to claim 1, characterized in that: The mass ratio of roasted copper slag to manganese salt is 0.8-1.7:1, and the mass ratio of potassium permanganate to roasted copper slag is 0.3-0.8:

1.

3. The application of the copper slag-based amorphous composite material according to any one of claims 1-2 in the oxidation-adsorption of organic arsenic.

4. The application according to claim 3, characterized in that: Organic arsenic is p-aminobenzoarsine.

Images