An adsorbent material for cadmium and lead in mine wastewater, its preparation method and application

Abstract

The present invention is applicable to the field of water body restoration technology, and provides a cadmium and lead adsorption material for mine wastewater, a preparation method thereof and an application. The adsorption material comprises the following components: montmorillonite powder, olivine slag powder and hydrochloric acid. The preparation method comprises the following steps: respectively taking olivine slag powder and montmorillonite powder, and calcining to obtain heat-modified olivine slag and heat-modified montmorillonite; weighing a total of 10 g of heat-modified montmorillonite and heat-modified olivine slag, mixing them according to a certain ratio to obtain a sample; adding a hydrochloric acid solution to the sample, stirring at 100 °C for 6 h, and cooling to room temperature; rinsing with deionized water multiple times until no Cl is detected by an AgNO3 solution ‑ ; drying and grinding the sample to obtain the final modified adsorption material. The method proposed by the present invention improves the porosity and specific surface area of olivine and montmorillonite, changes the crystal structure, improves the adsorption capacity, and is of great significance for the adsorption of heavy metals in wastewater and the sustainable development of water bodies.

Description

Technical Field

[0001] The present invention belongs to the technical field of water body restoration, and particularly relates to a cadmium and lead adsorption material for mine wastewater, a preparation method thereof, and an application thereof. Background Art

[0002] Mine industrial wastewater is wastewater containing suspended solids, organic pollutants, and various heavy metal ions generated during the mining process. The discharge of untreated mine industrial wastewater has adverse effects on soil, water environment, human health, etc. Mine industrial wastewater will damage the physical and chemical properties of soil, change the soil structure, and affect the microbial activity in the soil. After entering the water body, it will pollute the water body, change the water environment, and destroy its self-purification ability. The heavy metals in mine industrial wastewater can be enriched in the human body through the food chain and food web, inducing multi-organ damage and causing neurological diseases. Therefore, mine industrial wastewater must be treated to meet the standards (Integrated Wastewater Discharge Standard (GB8978-1996)) before discharge.

[0003] Common heavy metal pollution remediation mainly includes electrochemistry method, ion exchange method, adsorption method, precipitation method, bioremediation method, etc. The adsorption method is widely used due to its advantages of high removal efficiency, low cost, easy implementation, and no secondary pollution. Clay minerals can be used as high-quality and efficient heavy metal adsorption materials because of their rich content, large specific surface area, and high cation exchange capacity. The advantages of modified clay minerals are mainly reflected in the increase of specific surface area, pore size, and layer spacing, the improvement of cation exchange capacity, the increase of heavy metal ion binding sites, and the removal of interlayer impurities. The method of modified clay minerals adsorbing heavy metals is suitable for the adsorption of heavy metals in wastewater due to its high reaction efficiency, stable process, non-toxic and pollution-free, and low economic cost. Therefore, we propose a cadmium and lead adsorption material for mine wastewater, a preparation method thereof, and an application thereof. Summary of the Invention

[0004] The purpose of the present invention is to provide a cadmium and lead adsorption material for mine wastewater, a preparation method thereof, and an application thereof, aiming to solve the problems raised in the above background art.

[0005] To achieve the above purpose, the present invention provides the following technical solutions:

[0006] A preparation method of a cadmium and lead adsorption material for mine wastewater, the adsorption material comprising the following components: montmorillonite powder, olivine slag powder, and hydrochloric acid;

[0007] The preparation method comprises the following steps:

[0008] Step S1: Respectively take olivine slag powder and montmorillonite powder and calcine them at 500 °C for 6 h to obtain heat-modified olivine slag and heat-modified montmorillonite;

[0009] Step S2: Weigh a total of 10 g of heat-modified montmorillonite and heat-modified olivine slag. The heat-modified montmorillonite and heat-modified olivine slag are mixed in a certain ratio to obtain a sample;

[0010] Step S3: Add 500 mL of 1 mol / L hydrochloric acid solution to the sample obtained in Step S2, stir at 100 °C for 6 h, and cool to room temperature;

[0011] Step S4: Rinse with deionized water multiple times until no Cl is detected by AgNO3 solution - ;

[0012] Step S5: Dry the sample obtained in Step S4 in an oven at 50 °C for 2 days, and grind it to 200 mesh to obtain the final modified adsorbent material.

[0013] Further, in Step S2, the heat-modified montmorillonite and heat-modified olivine slag are mixed in a ratio of 0:10, and it is named modified slag.

[0014] Further, in Step S2, the heat-modified montmorillonite and heat-modified olivine slag are mixed in a ratio of 2:8, and it is named G8M2.

[0015] Further, in Step S2, the heat-modified montmorillonite and heat-modified olivine slag are mixed in a ratio of 5:5, and it is named G5M5.

[0016] Further, in Step S2, the heat-modified montmorillonite and heat-modified olivine slag are mixed in a ratio of 8:2, and it is named G2M8.

[0017] Further, in Step S2, the heat-modified montmorillonite and heat-modified olivine slag are mixed in a ratio of 10:0, and it is named modified montmorillonite.

[0018] An adsorbent material is prepared according to the preparation method.

[0019] An application of an adsorbent material, the adsorbent material is used to remove Cd and Pb in wastewater.

[0020] Further, add 1 - 6 g of the modified adsorbent material to every 1 L volume of wastewater containing Cd and Pb, stir well, and an obvious adsorption effect will be shown after 60 - 120 min.

[0021] Compared with the prior art, the beneficial effects of the present invention are:

[0022] 1. The method proposed by the present invention improves the porosity and specific surface area of olivine and montmorillonite, changes the crystal structure, improves the adsorption capacity, and is of great significance for the adsorption of heavy metals in wastewater and the sustainable development of water bodies;

[0023] 2. The raw materials used in the present invention, montmorillonite and olivine slag, are cheap and easily available. Moreover, olivine slag is a waste generated during the process of mineral development, which is in line with the concept of green economy. In addition, the operation of the present invention is simple, making up for the defects of complex operation, high cost and easy introduction of secondary pollution in the conventional methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 Among them: (a) Microscopic image of olivine slag; (b) Microscopic image of heat-modified olivine slag; (c)(d) Microscopic images of acid-heat-modified olivine slag; (e)(f) Microscopic images of acid-heat-modified montmorillonite slag; (g)(h) Microscopic images of composite material G2M8; (i)(j) Microscopic images of composite material G5M5; (k)(l) Microscopic images of composite material G8M2.

[0025] Figure 2 This is the XRD spectrum of the olivine slag sample of the present invention.

[0026] Figure 3 This is the FT-IR spectrum of the olivine slag sample of the present invention.

[0027] Figure 4 This is the XRD spectrum of the modified adsorption material of the present invention.

[0028] Figure 5 This is the FT-IR spectrum of the modified adsorption material of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0029] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0030] The following describes in detail the specific implementation of the present invention with reference to specific embodiments.

[0031] A preparation method of an adsorption material for cadmium and lead in mine wastewater provided by an embodiment of the present invention, the adsorption material includes the following components: montmorillonite powder, olivine slag powder and hydrochloric acid;

[0032] The preparation method includes the following steps:

[0033] Step S1: Respectively take the olivine slag powder and the montmorillonite powder and calcine them at 500 °C for 6 h to obtain heat-modified olivine slag and heat-modified montmorillonite;

[0034] Step S2: Weigh a total of 10 g of heat-modified montmorillonite and heat-modified olivine slag. The heat-modified montmorillonite and heat-modified olivine slag are mixed in the ratios of 0:10, 2:8, 5:5, 8:2, and 10:0, and are respectively named modified slag, G8M2, G5M5, G2M8, and modified montmorillonite;

[0035] Step S3: Add 500 mL of 1 mol / L hydrochloric acid solution to the samples obtained in Step S2, stir at 100 °C for 6 h, and cool to room temperature;

[0036] Step S4: Rinse with deionized water multiple times until no Cl is detected by AgNO3 solution - ;

[0037] Step S5: Dry the samples obtained in Step S4 in an oven at 50 °C for 2 days, and grind them to 200 meshes to obtain the final modified adsorption material.

[0038] An adsorption material provided by an embodiment of the present invention is prepared according to the preparation method.

[0039] An application of an adsorption material provided by an embodiment of the present invention, wherein the adsorption material is used to remove Cd and Pb in wastewater.

[0040] As a preferred embodiment of the present invention, 1 - 6 g of the modified adsorption material is added to each 1 L volume of wastewater containing Cd and Pb, stirred well, and an obvious adsorption effect is shown after 60 - 120 min.

[0041] For the prepared modified adsorption material, the adsorption effect can be evaluated by the following method:

[0042] (1) Microscopic characterization of the composite material: Use SEM to obtain the surface characteristics of olivine slag, montmorillonite, and the composite material before and after modification. The unmodified olivine slag has a larger particle size and a layered structure ( Figure 1 a). After high-temperature roasting, impurities in the slag are removed, and the large-particle-size slag is broken into smaller particle sizes ( Figure 1 b). After acid modification, the slag has smaller particle size, more porous structure, increased dispersion degree, broken edges, and increased specific surface area due to H+ dissolving carbonate mineral impurities and metal oxides, etc. ( Figure 1 c, 1d). Compared with olivine slag, acid-modified montmorillonite has a more porous and rough surface, more obvious layered structure, larger specific surface area, sharp edges, small particle size, and strong stacking property ( Figure 1 e, 1f). The microscopic characteristics of the composite material G2M8 are similar to those of montmorillonite, but it contains slag with a relatively smooth surface compared with it, and still obviously maintains the stacking property of montmorillonite ( Figure 1g, 1h). The microscopic features of the composite material G5M5 take into account the small particle size of montmorillonite and also include a large amount of slag with large particle sizes. This composite material combines all the characteristics of both. Figure 1 i, 1j). The microscopic features of the composite material G8M2 are similar to those of slag, and the montmorillonite content is relatively low. Figure 1 k, 1l). The surface morphology characteristics of both slag and montmorillonite are present in the composite material, indicating that the two have been successfully compounded.

[0043] (2) XRD and FT-IR infrared spectroscopy analysis: The XRD results of the modified olivine slag samples show that the original samples mainly contain serpentine, olivine, enstatite, and quartz. Figure 2 ). The diffraction angles 2θ of olivine are 20.6°, 36.5°, and 65.2°, those of serpentine are 12.5°, 18.6°, and 25.0°, and the characteristic peaks of quartz and enstatite are located at 26.5° and 28.5°. After calcination at 600 °C, the characteristic peak of Fe2O3 (2θ = 33.1°) appears. For the acid-thermal modified olivine, new characteristic peaks belonging to olivine appear at diffraction angles 2θ of 36.5°, 55.7°, and 60.8°. The intensity of the serpentine characteristic peak decreases, while the characteristic peaks of quartz and enstatite increase, indicating that the serpentine in the slag is transformed into olivine and enstatite by acid-thermal modification, and the reaction is as shown in Equation (1). Olivine can be oxidized to form Fe2O3 at high temperatures.

[0044] 2Mg3Si2O5(OH)4 → 2Mg2SiO4 + 2MgSiO3 + 4H2O (1)

[0045] At 3676 cm -1 is the stretching vibration peak of Mg-OH. At 3446 cm -1 and 1635 cm -1 are the stretching vibration peaks of bound water -OH. At 1419 cm -1 is the stretching vibration peak of CO3 2- impurities. At 1020 cm -1 , 781 cm -1 , and 757 cm -1 are the stretching vibration peaks of Si-O, Si-O-Al, and Si-O-Si respectively. At 699 cm -1 is related to Mg-O. The positions of the characteristic peaks before and after modification correspond Figure 3 ), but there are slight differences in the peak intensities. After modification, the CO3 2- impurities in the slag are effectively removed, and the characteristic peaks related to olivine are enhanced.

[0046] The XRD spectra of the three composite materials show that they simultaneously contain the diffraction peaks of montmorillonite and olivine slag, indicating that the montmorillonite and olivine slag in the composite material are successfully compounded and uniformly dispersed.Figure 4 ) The peaks of montmorillonite with diffraction angles 2θ of 6.8°, 19.9°, and 62.1° all appear in G2M8 and G5M5, while the peak with a diffraction angle of 62.1° does not appear in G8M2. The diffraction peaks of olivine slag all appear in G8M2. The peak of olivine with a diffraction angle of 36.5° and the peak of serpentine with a diffraction angle of 25.0° do not appear in G2M8 and G5M5, and the pyroxene peak does not appear in G2M8. G5M5 contains the most diffraction peaks of montmorillonite and olivine slag and is the best composite material.

[0047] The FT-IR spectra of the three composite materials contain the Al-OH stretching vibration peak at 3627 cm -1 of montmorillonite, as well as the Mg-OH peak and Mg-O peak of olivine slag ( Figure 5 ). Affected by the Si-O stretching vibration peak at 1046 cm -1 of montmorillonite and the Si-O stretching vibration peak at 1020 cm -1 of olivine, the Si-O peak of G5M5 is shifted (1042 cm -1 ). Affected by the peaks at 796 cm -1 of montmorillonite and 781 cm -1 of olivine, the Si-O-Al peak of G8M2 is shifted (794 cm -1 ). Consistent with the XRD results, G5M5 contains the most characteristic peaks of montmorillonite and olivine slag and is the best composite material.

[0048] (3) Laboratory simulation adsorption experiment: To determine the optimal adsorption conditions of the modified composite material, the following experiments were carried out. Binary simulated waste liquids were prepared respectively through 1000 mg / L Pb and Cd standard solutions, and batch experiments were conducted on the initial concentrations, dosages, pH values, and oscillation times of the two heavy metal elements. Ⅰ. The initial concentrations of heavy metals were 2 mg / L, 5 mg / L, and 10 mg / L respectively; Ⅱ. The dosages were 1 g / L, 2 g / L, and 6 g / L; Ⅲ. The pH gradient was 3, 4, and 5; Ⅳ. The oscillation times were 60 min, 90 min, and 120 min. The optimal conditions for heavy metal adsorption were determined through multiple experiments. 50 mL of the prepared simulated waste liquid was placed in a 100 mL conical flask, and a certain amount of modified mineral material was added respectively, and oscillated at a speed of 200 r / min until adsorption equilibrium was reached, then filtered, diluted, and the heavy metal content in the sample was measured by atomic absorption.

[0049] Result calculation: The adsorption rate of the modified material for heavy metals in water is calculated as a percentage: W—represents the removal rate of heavy metals in the solution as a percentage;

[0050] C1—represents the heavy metal concentration in the original solution, mg / L;

[0051] C2—The heavy metal concentration in the solution after adsorption, mg / L.

[0052] The results measured by the above method are shown in Table 1.

[0053] Table 1 Adsorption effects of modified mineral materials under different conditions

[0054]

[0055] According to the above experimental results, the optimal adsorption conditions of the modified material can be determined: the greater the pH, the better the adsorption effects on Cd and Pb. The adsorption reaches equilibrium at about 90 min, and the removal rate increases with the increase of the dosage. G5M5 is the best adsorption material, and the maximum removal rates for Cd and Pb are 40.39% and 91.63% respectively, and the optimal adsorption capacities are 15.53 mg / g and 42.17 mg / g respectively. The adsorption effect is obvious, and the adsorption capacity varies greatly with the change of the initial concentration and dosage.

[0056] In the present invention, the raw materials montmorillonite and olivine slag used are cheap and easily available, and the olivine slag belongs to the waste generated during the mineral development process, which is green economy. High-temperature roasting can remove the impurities in montmorillonite and olivine slag, remove adsorbed water, crystal water, structural water, etc., and promote the phase change of olivine slag. This method can increase the porosity and specific surface area of olivine and montmorillonite, change the crystal structure, and improve the adsorption capacity. Acid activation can change the crystal structure of clay minerals, open channels, + exchange the interlayer cations, improve the surface acidity, increase the specific surface area, and provide a site for the subsequent adsorption reaction. Acid activation increases the specific surface area of olivine slag and also generates tiny pores on the surface of olivine slag, and the collapse of micropores increases the porosity. The operation of the present invention is simple and green economy, making up for the defects of complex operation, high cost and easy introduction of secondary pollution in the conventional methods.

[0057] Example 1: The sample is the industrial wastewater collected from a mining company. Its pH is measured to be 5.12. After the collected water sample is filtered by suction, it is evenly divided into 3 parts and numbered S1 - S3. At the same time, the modified adsorption material (G5M5) made of montmorillonite powder and olivine powder in a mass ratio of 5:5 is added to the above water sample (2 g of the modified adsorption material is added to every 1 L of water. After fully mixing, it is oscillated for 90 min). After adsorption, it is numbered G1 - G3. After filtration, the cadmium and lead contents in the water before and after adding the adsorbent are measured, and the results are shown in Table 2.

[0058] Table 2 Water sample measurement results

[0059] Sample number Cd (mg / L) Pb (mg / L) Sample number Cd (mg / L) Pb (mg / L) Cd (%) Pb (%) S1 0.185 5.623 G1 0.046 0.692 75.216 87.693 S2 0.183 5.486 G2 0.046 0.654 74.973 88.079 S3 0.180 5.418 G3 0.051 0.623 71.818 88.501 Average value of Si 0.183 5.509 Average value of Gi 0.047 0.656 74.002 88.091 Relative standard deviation (%) 1.358 1.895 Relative standard deviation (%) 5.964 5.265 2.562 0.459

[0060] Among them, the calculation formula of the relative standard deviation and (where n is the number of measurements of the sample; Si and Gi are the i-th measured values of the initial Cd and Pb concentrations and the final Cd and Pb concentrations, and are the average values of the n measurements).

[0061] The following conclusions can be drawn from the analysis of the measurement results of the water samples before and after adsorption:

[0062] 1. After adding the composite modified adsorbent material, the contents of Cd and Pb in the water decreased significantly. The adsorption rates were 71.818% - 75.216% and 87.693% - 88.501% respectively, and the average adsorption rates were 74.002% and 88.091% respectively. The adsorption effect was remarkable, indicating that in the mine industrial wastewater with pH 5.12, and Cd and Pb concentrations of 0.180 - 0.185 mg / L and 5.418 - 5.623 mg / L respectively, the modified composite adsorbent material had good adsorption ability for Cd and Pb in the water.

[0063] 2. According to the maximum allowable emission concentrations of the first-class pollutants specified in the Integrated Wastewater Discharge Standard (GB8978 - 1996), the average contents of Cd and Pb in the water before repair reached 0.183 mg / L and 5.509 mg / L, far exceeding the standard. After repair, the average contents of Cd and Pb in the water were 0.047 mg / L and 0.656 mg / L, less than the maximum allowable emission concentrations (Cd 0.1 mg / L, Pb 1.0 mg / L), and the pollution degree was significantly improved.

[0064] 3. In the method of the present invention, the relative standard deviation values were between 0.459% and 5.964%, indicating that the method had high precision and the test results of the instrument were stable.

[0065] Example 2. A modified adsorbent material provided by an embodiment of the present invention includes the following components: montmorillonite powder, olivine slag powder, hydrochloric acid.

[0066] Respectively take the slag powder and montmorillonite powder and calcine them at 500 °C for 6 h to obtain heat-modified slag and heat-modified montmorillonite; weigh a total of 10 g of the above-mentioned montmorillonite powder and olivine slag powder, and mix them in a ratio of montmorillonite:olivine slag equal to 2:8; add 500 mL of 1 mol / L hydrochloric acid solution to the above sample, stir at 100 °C for 6 h, and cool to room temperature; rinse with deionized water multiple times until no Cl is detected by AgNO3 solution - ; dry the above sample in an oven at 50 °C for 2 days and grind it to 200 meshes to obtain the final composite material (G8M2).

[0067] The modified adsorbent material prepared by the above process can be used to adsorb Cd and Pb in mine industrial wastewater.

[0068] The method for removing Cd and Pb from mine industrial wastewater is as follows: Add 2 g of the above modified material to 1 L of Cd- and Pb-containing wastewater (the same water sample as in Example 1), and stir well to mix evenly. After 90 min, an obvious adsorption effect will be manifested. Measure the Cd and Pb contents in the water sample before and after adsorption, and the measurement results are shown in Tables 3 and 4.

[0069] Example 3. A modified adsorption material provided by an embodiment of the present invention includes the following components: olivine slag powder and hydrochloric acid.

[0070] Take slag powder and calcine it at 500 °C for 6 h to obtain heat-modified slag; Weigh 10 g of the above olivine slag powder and add it to 500 mL of 1 mol / L hydrochloric acid solution, stir at 100 °C for 6 h, and cool to room temperature; Rinse it with deionized water multiple times until no Cl is detected by AgNO3 solution - ; Dry the above sample in an oven at 50 °C for 2 days and grind it to 200 meshes to obtain the final modified material (modified slag).

[0071] The modified adsorption material prepared by the above process can be used to adsorb Cd and Pb in mine industrial wastewater.

[0072] The method for removing Cd and Pb from mine industrial wastewater is as follows: Add 2 g of the above modified material to 1 L of Cd- and Pb-containing wastewater (the same water sample as in Example 1), and stir well to mix evenly. After 90 min, an obvious adsorption effect will be manifested. Measure the Cd and Pb contents in the water sample before and after adsorption, and the measurement results are shown in Tables 3 and 4.

[0073] Example 4. A modified adsorption material provided by an embodiment of the present invention includes the following components: montmorillonite powder, olivine slag powder, hydrochloric acid.

[0074] Take slag powder and montmorillonite powder and calcine them at 500 °C for 6 h to obtain heat-modified slag and heat-modified montmorillonite; Weigh a total of 10 g of the above montmorillonite powder and olivine slag powder, and mix them in a ratio of montmorillonite: olivine slag = 8:2; Add 500 mL of 1 mol / L hydrochloric acid solution to the above sample, stir at 100 °C for 6 h, and cool to room temperature; Rinse it with deionized water multiple times until no Cl is detected by AgNO3 solution - ; Dry the above sample in an oven at 50 °C for 2 days and grind it to 200 meshes to obtain the final composite material (G2M8).

[0075] The modified adsorption material prepared by the above process can be used to adsorb Cd and Pb in mine industrial wastewater.

[0076] The method for removing Cd and Pb from mine industrial wastewater is as follows: Add 2 g of the above-mentioned modified material to 1 L of Cd- and Pb-containing wastewater (the same water sample as in Example 1), and stir well to mix evenly. After 90 min, an obvious adsorption effect will be shown. Measure the Cd and Pb contents in the water sample before and after adsorption, and the measurement results are shown in Tables 3 and 4.

[0077] Example 5. A modified adsorption material provided by an embodiment of the present invention comprises the following components: montmorillonite powder and hydrochloric acid.

[0078] Take montmorillonite powder and calcine it at 500 °C for 6 h to obtain heat-modified montmorillonite powder; weigh 10 g of the above-mentioned montmorillonite powder and add it to 500 mL of 1 mol / L hydrochloric acid solution, stir at 100 °C for 6 h, and cool to room temperature; rinse it with deionized water multiple times until no Cl is detected by AgNO3 solution - ; Dry the above sample in an oven at 50 °C for 2 days, and grind it to 200 meshes to obtain the final modified material (modified montmorillonite).

[0079] The modified adsorption material prepared by the above process can be used to adsorb Cd and Pb in mine industrial wastewater.

[0080] The method for removing Cd and Pb from mine industrial wastewater is as follows: Add 2 g of the above-mentioned modified material to 1 L of Cd- and Pb-containing wastewater (the same water sample as in Example 1), and stir well to mix evenly. After 90 min, an obvious adsorption effect will be shown. Measure the Cd and Pb contents in the water sample before and after adsorption, and the measurement results are shown in Tables 3 and 4.

[0081] Table 3 Measurement results of the repaired water sample

[0082]

[0083] Table 4 Adsorption rate of the modified material

[0084]

[0085] In view of Examples 1-5, the composite material (G5M5) prepared from montmorillonite powder and olivine slag powder at a ratio of 5:5 has the best adsorption effect, and the adsorption rates of Cd and Pb can reach 71-75% and 87-88% respectively. The adsorption effects of the composite materials (G8M2, G2M8) prepared at ratios of 2:8 and 8:2 are weaker, and the adsorption rates of Cd and Pb can reach 65-71% and 68-86% respectively. The modified olivine slag powder has the best adsorption effect on Pb, reaching 97%, but the worst adsorption effect on Cd, only 19-22%. The modified montmorillonite powder has a better adsorption effect on Cd, reaching 68-71%, but the worst adsorption effect on Pb, only 57-59%. According to the maximum allowable discharge concentration of the first-class pollutants specified in the Comprehensive Wastewater Discharge Standard (GB8978-1996), after adsorption in Examples 1 and 2 (G5M5, G8M2), the Cd and Pb in the wastewater meet the discharge standards. After adsorption in Example 3 (modified slag), only Pb in the wastewater meets the discharge standards. After adsorption in Examples 4 and 5 (G2M8, modified montmorillonite), only Cd in the wastewater meets the discharge standards. The reasons are analyzed as follows: Ⅰ. The modified olivine slag powder has a strong adsorption ability for Pb in the wastewater, and the modified montmorillonite powder has a strong adsorption ability for Cd in the wastewater. Therefore, the composite material combines the advantages of both and can adsorb Cd and Pb in industrial wastewater simultaneously. Ⅱ. The composite material with a higher montmorillonite content inherits its adsorption ability for Cd, but has a weaker adsorption ability for Pb. The composite material with a higher slag content inherits its adsorption ability for Pb and reduces the adsorption ability for Cd. Therefore, the above two cannot achieve a good adsorption condition.

[0086] The above is only the preferred implementation mode of the present invention. It should be noted that for those skilled in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, which should also be regarded as the protection scope of the present invention, and these will not affect the implementation effect of the present invention and the practicality of the patent.

Claims

1. Application of an adsorbent material for cadmium and lead in mine wastewater, characterized in that, The adsorbent material is used to remove Cd and Pb in wastewater; The adsorbent material comprises the following components: montmorillonite powder, olivine slag powder and hydrochloric acid; The preparation method of the adsorbent material comprises the following steps: Step S1: Respectively take olivine slag powder and montmorillonite powder and calcine them at 500 °C for 6 h to obtain heat-modified olivine slag and heat-modified montmorillonite; Step S2: Weigh a total of 10 g of heat-modified montmorillonite and heat-modified olivine slag, and mix the heat-modified montmorillonite and heat-modified olivine slag in a certain proportion to obtain a sample; Step S3: Add 500 mL of 1 mol / L hydrochloric acid solution to the sample obtained in Step S2, stir at 100 °C for 6 h, and cool to room temperature; Step S4: Rinse with deionized water multiple times until no Cl is detected by AgNO3 solution - ; Step S5: Dry the sample obtained in Step S4 in an oven at 50 °C for 2 days, and grind it to 200 mesh to obtain the final modified adsorbent material; In Step S2, the heat-modified montmorillonite and the heat-modified olivine slag are mixed in a ratio of 5:5, named G5M5.

2. According to the application of the adsorbent material described in claim 1, 1-6 g of the modified adsorbent material is added to every 1 L volume of wastewater containing Cd and Pb, stirred and mixed well, and an obvious adsorption effect is shown after 60-120 min.

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