CN107159127B - Preparation method and application of adsorbent for heavy metal and dye adsorption - Google Patents

Abstract

The invention discloses a preparation method and application of an adsorbent for adsorbing heavy metals and dyes, and belongs to the field of adsorption materials. The method comprises the following steps: mixing WCl₆Dissolving in triethylene glycol, and adding glucose to obtain a uniform mixture; transferring the mixture into a reaction kettle, heating to 200 ℃ and maintaining for 6 hours; and after cooling, centrifugally collecting the nanowire net, washing, and freeze-drying to obtain the adsorbent. The application of the adsorbent is as follows: adding the adsorbent into a heavy metal or dye solution, uniformly dispersing, carrying out centrifugal separation after adsorption balance, taking clear liquid and calculating the adsorption quantity of the adsorbent. In the preparation process, W₁₈O₄₉The three-dimensional nanowire network of (a) is functionalized with a carbonaceous layer having different oxygen-containing functional groups. Pb removal by prepared adsorbent²⁺And methylene blue, which is Pb-removing owing to its rapid adsorption equilibrium and particularly high adsorption capacity²⁺And methylene blue, among the most promising materials.

Description

Preparation method and application of adsorbent for heavy metal and dye adsorption

Technical Field

The invention relates to a preparation method and application of an adsorbent for adsorbing heavy metals and dyes, and belongs to the field of adsorption materials.

Background

The rapid development of the industrial process brings great convenience to the life of people, and simultaneously produces a large amount of industrial wastewater, particularly the wastewater containing a large amount of heavy metal ions and organic dyes has increasingly serious pollution to the environment. Because of their extreme toxicity, carcinogenesis and their constant accumulation in the body via the food chain, pose a long-term threat to human health and the natural ecosystem. Therefore, how to treat wastewater containing a large amount of heavy metal ions and organic dyes with high efficiency draws attention, and this has become the key and difficult point of wastewater treatment at present. Various water purification techniques have been developed to treat heavy metal ions and organic dyes, including electrochemical precipitation, ion exchange, adsorption, ultrafiltration, photocatalysis, and reverse osmosis. Among them, adsorption technology is considered an economical, efficient and green process due to its simplicity, high efficiency and low operating cost. Adsorbents are critical to adsorption technology and therefore the design and synthesis of high performance adsorbents. Therefore, there is an urgent need to develop an advanced adsorbent material having high adsorption capacity and high efficiency, which is an environmentally friendly, easily recyclable and renewable material.

Currently, various inorganic and organic adsorbents, including carbonaceous nanomaterials, metal oxides, natural clays and biomass, cannot meet the increasing demand due to the limited adsorption capacity and reduced adsorption rate resulting from the relatively weak affinity between the adsorbent and heavy metal ions. Further research and development of adsorbents having high adsorption capacity and excellent adsorption rate for heavy metal ions and organic dyes have been the focus of research.

Tungsten oxide (W)₁₈O₄₉) The nano material is a non-toxic and environment-friendly multifunctional material, and can be used for preparing W with different shapes by a series of methods₁₈O₄₉Such as multilayer nanoflower, nanosheets, nanostructured hollow spheres, and the like, have been widely used in various fields, such as photocatalysis, lithium ion batteries, supercapacitors, and adsorption. One-dimensional ultra-fine nanotubes and nanowires (diameter)<10nm) are more attractive than other shapes of nanostructured materials due to their unique properties and potential applications. For W₁₈O₄₉Nanowires, already employing W₁₈O₄₉Nanowire pair Pb²⁺And Methylene Blue (MB) with a maximum adsorption capacity (MB of about 201mg/g, Pb)²⁺About 192mg/g) are still lower than many other advanced sorbents, such as sandwich-like magnesium silicateReduced graphene oxide graphite (for Pb)²⁺And adsorption capacities of MB of 416 and 433mg/g, respectively), polymer graphene oxide (for Pb)²⁺Has an adsorption capacity of 887.98mg/g), ZnO/ZnFe₂O₄C (for Pb)²⁺Has an adsorption capacity of 344.83 mg/g). To further improve W₁₈O₄₉Binding an organic functional group having affinity for heavy metal ions and organic dyes to W₁₈O₄₉Medium, i.e. inorganic-organic hybrid W₁₈O₄₉Matrix composites are a desirable method. Song et al W synthesized by solvothermal method₁₈O₄₉The ethylene diamine inorganic-organic hybrid nano-wire has excellent adsorption capacity on various heavy metal ions due to the use of ethylene diamine. However, ethylenediamine is harmful to the environment. Currently, a carbonaceous material hydrothermally carbonized with glucose having abundant hydrophilic functional groups (such as OH, COOH, and C ═ O) has a stronger chelating ability for heavy metal ions, and has been used to functionalize an inorganic adsorbent to improve its adsorption performance. However, modification of carbonaceous materials is generally time consuming and complicated.

Disclosure of Invention

The invention aims to provide a preparation method and application of an adsorbent for adsorbing heavy metals and dyes, and belongs to the field of adsorption materials. Therefore, we imagine that it is possible to form an excellent adsorbent with a unique heterogeneous surface, strong affinity to heavy metal ions and organic dyes, easy to produce, and scalable, by the combination of one-dimensional tungsten oxide nanomaterials as framework with carbonaceous materials.

The purpose of the invention is realized by the following technical scheme:

we prepared novel nano grass-like W by simple, high-yield solvothermal method₁₈O₄₉@ C inorganic-organic hybrid nanowire networks.

A preparation method of an adsorbent for heavy metal and dye adsorption comprises the following steps:

first, WCl₆Dissolving in triethylene glycol, and adding glucose while stirring to obtain a uniform mixture; then the saidTransferring the uniform mixture into a reaction kettle, heating to 200 ℃ and maintaining for 6 hours; after cooling, the nanowire net is collected by centrifugation, washed and freeze-dried to obtain the adsorbent. The adsorbent is named as W₁₈O₄₉@C。

Wherein WCl in said homogeneous mixture₆And the concentration of glucose is preferably 17.5 g/L;

the reaction kettle is preferably a stainless steel reaction kettle with a polytetrafluoroethylene lining;

the washing is preferably carried out by adopting absolute ethyl alcohol and deionized water;

the freeze-drying is preferably performed by freeze-drying the centrifugally collected nanowire mesh in a bulk tray dryer.

The application of the adsorbent for adsorbing heavy metal and dye comprises the following steps of:

firstly, lead ion solution is selected as simulated heavy metal pollution industrial wastewater. The adsorbent W is added₁₈O₄₉@ C to a concentration of C₀In lead ion solution, performing ultrasonic treatment for 5min to enable W₁₈O₄₉@ C is uniformly dispersed in the lead ion solution to obtain a mixed solution; then placing the mixed solution into a shaking table to shake for 24 hours so as to achieve adsorption balance; adjusting the pH value of the solution to 4.5 in the shaking process; after adsorption equilibrium, the mixture was centrifuged by a centrifuge, and the supernatant was collected and the lead ion concentration C was measured at 283.3nm by atomic absorption spectrometry_e(ii) a Amount of adsorbed lead ion Q_eIn mg/g, calculated from the following equation:

wherein V is the volume of the lead ion solution, and the unit is mL; m is the addition of the adsorbent, and the unit is mg; c₀And C_eThe initial and final concentrations of lead ion solution, respectively, were in mg/L.

The pH value is preferably 0.01-1moL/L HNO₃Solution or 0.01-1moL/L NaOH solutionTo make adjustments;

the centrifuge is preferably a high-speed centrifuge with the rotating speed of 8000 r/min.

The application of the adsorbent for adsorbing heavy metal and dye of the invention comprises the following steps of:

firstly, selecting a methylene blue solution as simulated dye wastewater. The adsorbent W is added₁₈O₄₉@ C to a concentration of C₀In methylene blue solution, W is treated by ultrasonic treatment for 5min₁₈O₄₉@ C is uniformly dispersed in the methylene blue solution, and then the mixed solution is put into a shaking table to be shaken for 24 hours so as to achieve adsorption balance; adjusting the pH value of the solution to 4.5 in the shaking process; after adsorption equilibrium, the mixture was centrifuged with a centrifuge, the supernatant was collected, and the concentration C of methylene blue was measured at 664nm by UV-visible absorption spectroscopy_e'; amount of adsorbed methylene blue Q_e', in mg/g, calculated from the following equation:

wherein V' is the volume of the methylene blue solution, and the unit is mL; m' is the addition of the adsorbent, and the unit is mg; c₀' and C_e' starting and final concentrations of methylene blue solution, respectively, are given in mg/L.

The pH value is preferably 0.01-1moL/L HNO₃Adjusting by using a solution or 0.01-1moL/L NaOH solution;

the centrifuge is preferably a high-speed centrifuge with the rotating speed of 8000 r/min.

Advantageous effects

During the synthesis, W₁₈O₄₉The three-dimensional nanowire network of (a) is functionalized with a carbonaceous layer having different oxygen-containing functional groups. The W prepared by the method has unique cross hierarchical structure and rich active sites in the adsorbent material₁₈O₄₉@ C nanowire network for the removal of Pb from aqueous solutions²⁺And MB, which is removed from the waste water due to its rapid adsorption equilibrium and particularly high adsorption capacityRemoving Pb²⁺And MB, one of the most promising materials. The ion exchange and electrostatic attraction is W₁₈O₄₉@ C nanowire network for rapid and high-capacity Pb removal²⁺And the main contribution of the MB. All these outstanding properties mean W₁₈O₄₉The @ C nanowire network can be used as a novel feasible adsorbent with ultra-fast and high adsorption capacity for removing heavy metals and organic pollutants from wastewater.

Drawings

FIG. 1 is W₁₈O₄₉And W₁₈O₄₉The (A) XRD pattern, (B) FTIR spectrum, (C) N2 adsorption/desorption isotherm and (D) zeta potential vs. W of @ C₁₈O₄₉And W₁₈O₄₉The pH of the @ C network;

FIG. 2 is W₁₈O₄₉And W₁₈O₄₉XPS spectra of @ C network: (A) measuring the spectrum, (B) and (D) the 4f orbits of the W element, (C) and (E) the 1s orbits of the O element;

in FIG. 3A and B are W₁₈O₄₉SEM images of (A), (B) and (D) are W₁₈O₄₉SEM images of the @ C network;

in FIG. 4, A and B are Pb²⁺And MB is at W₁₈O₄₉And W₁₈O₄₉Two kinetic equations corresponding to the adsorption kinetics on @ C; c and D are at W₁₈O₄₉And W₁₈O₄₉@ C and Pb on Langmuir and Froude isotherms, respectively²⁺And adsorption isotherm for MB adsorption.

Wherein, XRD is X-ray diffraction, FTIR is Fourier infrared spectrum, XPS is X-ray photoelectron spectrum, and SEM is scanning electron microscope.

Detailed Description

The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, but is not limited thereto.

Example 1

First, 0.7g of WCl was added₆Dissolved in 40ml of triethylene glycol to obtain a solution and then 0.7g of glucose is added during continuous stirring to obtain a homogeneous mixture, wherein WCl₆And the concentration of glucose was 17.5 g/L. However, the device is not suitable for use in a kitchenThe homogeneous mixture was then transferred to a 100mL stainless steel autoclave lined with polytetrafluoroethylene, heated to 200 ℃ and maintained for 6 hours. After cooling, the nanowire networks were collected by centrifugation and washed with absolute ethanol and deionized water. Freeze-drying the collected nanowire mesh in a bulk tray dryer to obtain the adsorbent for adsorbing heavy metal and dye, wherein the adsorbent is named as W₁₈O₄₉@C。

W₁₈O₄₉Test for removal of heavy Metal ions @ C: firstly, lead ion solution is selected as simulated heavy metal pollution industrial wastewater. _{18 49}Weighing 0.1g/L of WO @ C(20mg) was added to a 120mg/L lead ion solution (200mL), and W was sonicated for 5min₁₈O₄₉@ C is uniformly dispersed in the lead ion solution to obtain a mixed solution. Then the mixed solution is put into a shaking table and shaken for 24 hours to achieve adsorption balance. In the process, 0.01-1Mol/L HNO is added₃Or NaOH solution to adjust the pH of the solution to 4.5. After the adsorption equilibrium, the mixed solution was centrifuged (rotation speed 8000r/min) by a high-speed centrifuge, and the supernatant was taken to measure Pb at 283.3nm by atomic absorption spectrometry (AAS-6300C, Shimadzu, Japan)²⁺Concentration C_e(42.68 mg/L). Amount of adsorbed lead ion Q_e(mg/g) can be calculated by the following equation:

wherein V is the volume (mL) of the lead ion solution, m is the amount (mg) of the adsorbent, C₀And C_eInitial and final concentrations (mg/L) of lead ion solution, respectively.

W₁₈O₄₉Removal test of methylene blue by @ C: firstly, selecting a methylene blue solution as simulated organic dye wastewater. Weighing 0.1g/L of W₁₈O₄₉@ C (20mg), added to a 200mg/L methylene blue solution (200mL), and sonicated for 5min to allow W to pass₁₈O₄₉@ C is uniformly dispersed in the methylene blue solution. Then the mixed solution is put into a shaking table and shaken for 24 hours to achieve adsorption balance. In this process, by adding 0.01-1M HNO₃Or adjusting pH to 4.5 with NaOH solution (after adsorption equilibrium, centrifuging the mixture with high speed centrifuge at 8000r/min), collecting supernatant, and measuring the concentration C of methylene blue at 664nm by ultraviolet visible absorption spectrometry (Shimadzu-2550)_e' (18.17 mg/L). Amount of adsorbed methylene blue Q_e' (mg/g) can be calculated by the following equation:

wherein V 'is the volume of methylene blue solution (mL), m' is the amount of adsorbent (mg), C₀' and C_e' starting and final concentrations (mg/L) of methylene blue solution, respectively.

As shown in FIG. 1A, W was identified by XRD analysis₁₈O₄₉And W₁₈O₄₉The crystal structure of the @ C network. W₁₈O₄₉And W₁₈O₄₉The main characteristic peak-to-peak values of the @ C network at 23.54 DEG and 47.93 DEG correspond to W₁₈O₄₉(JCPDS (Joint Committee on Powder Diffraction Standards) No.05-0393) in the (010) and (020) planes. As shown in FIG. 1B, FTIR was used to characterize W₁₈O₄₉And W₁₈O₄₉@ C surface functional groups on the network. W₁₈O₄₉And W₁₈O₄₉@ C at 1000-^-1The peak of the spectral region of (2) is due to the typical W₁₈O₄₉Caused by vibration, including vibration at-633 cm^-1The sum of tensile vibration of W-O-W at position is-937 cm^-1O ═ W, and at-812 cm^-1And O-W-O bending vibration. These results confirm the successful formation of W₁₈O₄₉A nanostructure. The presence of W-OH (oxygen vacancy) can be determined by a position of-1620 cm^-1The absorption peak at (a) was confirmed. At-3434 cm^-1The absorption peaks at (a) are induced by stretching and bending vibrations of-OH generated during hydrothermal carbonization of various oxygen functional groups on the carbonized product. For W₁₈O₄₉@ C at 1708, -1116 and-980 cm^-1The three characteristic peaks at (a) are respectively attributed to stretching vibration of C ═ O, stretching vibration of C — O, and stretching vibration of C — O — C group. These results indicate that the functional carbonaceous species are paired with W₁₈O₄₉The nanowires were successfully modified. That is, in the original W₁₈O₄₉A large number of oxygen functional groups are introduced on the surface of the nanowire network. These functional carbonaceous materials not only facilitate removal of heavy metal ions and dyes, but also improve the hydrophilicity of the adsorbent, which results in enhanced interaction between the adsorbent and adsorbate. N is a radical of₂The adsorption/desorption isotherms and pore distribution curves are shown in figure 1C. Original W₁₈O₄₉The specific surface area of the nanowire is about 115.63m²G, greater than W₁₈O₄₉82.51m of @ C²/g，W₁₈O₄₉The pore volume of @ C becomes smaller than W₁₈O₄₉Small (fig. 1C). This is probably because W is present after hydrothermal reaction₁₈O₄₉Is covered. Zeta potential measurements were made and are shown in fig. 1D. W₁₈O₄₉And W₁₈O₄₉The @ C nanowire network is negative throughout the pH range of about 2.0 to 12.0, with W even at higher pH values₁₈O₄₉Is the cathode. W₁₈O₄₉The functional groups of the @ C surface, such as hydroxyl, carboxyl and carbonyl groups, are responsible for the negative surface charge, which plays a key role in the retention of contaminants.

W was further detected by detection of XPS spectra as shown in FIG. 2₁₈O₄₉And W₁₈O₄₉Composition and functional groups of the @ C network, W₁₈O₄₉And W₁₈O₄₉@ C all show similar elemental compositions, as at about 531, about 260-248 and about 37eV, corresponding to the elemental species of O1, W4 d and W4 f, respectively (FIG. 2A). For W₁₈O₄₉@ C, the apparently strong peak at about 286eV is attributed to C1, which means that W₁₈O₄₉The nanowires are functionalized with carbonaceous material. FIG. 2B shows W₁₈O₄₉A spectrum of W4 f, which can be decomposed into four peaks, corresponding to W⁶⁺And W⁵⁺W4 f of_5/2And W4 f_7/2. At binding energies of-38.57 and 36.35eVThe observed characteristic peak corresponds to W⁶⁺State, while peaks at 38.21 and 35.87eV are assigned to W⁵⁺Peak value of (a). All results confirm W₁₈O₄₉In the presence of W⁶⁺And W⁵⁺In the form of (1). W⁵⁺The presence of (A) also clearly indicates W₁₈O₄₉Oxygen vacancies contained therein. W₁₈O₄₉W4 f of @ C also shows the same as W₁₈O₄₉Similar four curve peaks (fig. 2D). As shown in FIG. 2C, the peaks at-530.78 and 532.28eV in O1s correspond to W, respectively₁₈O₄₉O-W and W-OH (oxygen vacancy) of the nanowire W₁₈O₄₉Similar peaks were also observed in the XPS curves for the @ C nanowire (FIG. 2D), while a new peak for C-OH with binding energy at-534.08 eV is evidence of the presence of carbonaceous species. As a comparison of the O1s spectra, W₁₈O₄₉The oxygen functional groups (W-OH and C-O) of @ C (FIG. 2E) with W₁₈O₄₉The oxygen functional group (O-W) has a higher strength than the oxygen functional group (O-W). This is shown at W₁₈O₄₉@ C network surface ratio at W₁₈O₄₉More oxygen functional groups are formed on the surface of the nanowires. All these XPS results are in full agreement with the FTIR data and again confirm the W₁₈O₄₉The carbonaceous attachment and oxygen functionality on the surface of the @ C network.

Study of W by SEM₁₈O₄₉And W₁₈O₄₉The form of @ C (FIG. 3). FIG. 3A shows, original W₁₈O₄₉The morphology of the nanowires is aggregated and the material size of such layered formation is typically about 2-3 μm, rich radial nanowire bundles can be observed from the magnified SEM image (fig. 3B). At W₁₈O₄₉An interesting unique nanowire network morphology was observed in @ C (FIGS. 3C-D), in contrast to the original W₁₈O₄₉In contrast, the structure is loose rather than aggregated. Contaminants in the solution are readily adsorbed by the externally exposed adsorbent by electrostatic interaction or/and ion exchange. The prepared nanowires are only a few nanometers in size and therefore do not need to be considered internal surfaces or ignored. That is, W₁₈O₄₉Almost all surfaces of the @ C network are exposed to solution, contributing to contaminationAnd (4) adsorbing the substance.

In FIG. 4A and B the contact time vs. W is investigated₁₈O₄₉And W₁₈O₄₉@ C for adsorbing Pb²⁺And the effect of MB. Apparently, Pb²⁺And MB to W₁₈O₄₉And W₁₈O₄₉The adsorption of @ C is an ultra-fast process. A time of about 3 minutes is sufficient for W₁₈O₄₉Pb on²⁺And MB adsorption reached equilibrium respectively. Through W₁₈O₄₉And W₁₈O₄₉@ C removal of Pb²⁺And MB takes about 1 minute or even faster. This high adsorption efficiency indicates a high possibility of practical use. This observation can be attributed to W₁₈O₄₉Unique features of @ C: (1) at pH 5, (>25mV) around a high negative charge₁₈O₄₉The @ C nanowire network can accelerate Pb²⁺And diffusion and enrichment of MB, followed by sequestration, which is analogous to the so-called Donnan membrane effect; (2) the ultrathin nanowire network with abundant oxidized functional groups on the surface of the carbon-containing substance can provide many kinds of ions with Pb²⁺Active sites with high affinity, (3) ions or dyes readily pass through W₁₈O₄₉The @ C nanowire network is in a fluffy structure for adsorption; (4) most importantly, in W₁₈O₄₉The oxygen vacancies enriched in @ C constitute an atomic-scale interface of high surface free energy, to which small carbonaceous molecules can attach with high affinity and thus can serve as Pb²⁺An ion or dye anchor site.

Displays W of C and D in FIG. 4₁₈O₄₉And W₁₈O₄₉@ C to Pb²⁺Adsorption isotherm of and MB, W₁₈O₄₉And W₁₈O₄₉@ C to Pb²⁺And the adsorption capacity of MB is obviously increased, Pb²⁺And the initial concentration of MB is up to 147.6 and 81.2mg/L respectively. W₁₈O₄₉@ C to Pb²⁺The maximum adsorption capacity of MB and the maximum adsorption capacity of 1224.7 and 1188.3mg/g are higher than that of the original W₁₈O₄₉(Pb²⁺And MB at 600.2 and 550.7mg/g, respectively). Pb²⁺And the excellent adsorption capacity of MB may be attributed to the following synergistic effect: (1) with interconnected nano-tubesThe novel nanometer grass layered structure of the rice noodle network provides enough ion transmission channels, so that Pb can be conveniently absorbed on the adsorbent²⁺And MB diffuses from the outside to the inside; (2) a large number of negatively charged oxygen functional groups are exchanged for Pb by electrostatic attraction or ion exchange²⁺And MB adsorption provide more opportunities; (3) the widely exposed outer surfaces further give them sufficient adsorption sites for metal ion capture. W₁₈O₄₉@ C in removing Pb²⁺And MB shows a higher W than the original₁₈O₄₉Stronger removal capacity despite the original W₁₈O₄₉Has a high specific surface area, which indicates W₁₈O₄₉The decoration of the functional carbonaceous substance remarkably improves the adsorption performance of the functional carbonaceous substance. Further, W₁₈O₄₉Pb at @ C²⁺And MB is adsorbed within-1 minute to reach equilibrium, which is obviously faster than other adsorbents. This result, combined with the results of adsorption isotherms, strongly indicates that adsorbent W is present₁₈O₄₉@ C network for the removal and/or recovery of Pb therefrom²⁺And has great potential in MB.

The present invention includes, but is not limited to, the above embodiments, and any equivalent substitutions or partial modifications made under the principle of the spirit of the present invention are considered to be within the scope of the present invention.

Claims (4)

1. The application of the adsorbent for adsorbing heavy metal is characterized in that the adsorbent is used for removing heavy metal ions by the following steps:

firstly, selecting a lead ion solution as simulated heavy metal pollution industrial wastewater; the adsorbent W is added₁₈O₄₉@ C to a concentration of C₀In lead ion solution, performing ultrasonic treatment for 5min to enable W₁₈O₄₉@ C is uniformly dispersed in the lead ion solution to obtain a mixed solution; then placing the mixed solution into a shaking table to shake for 24 hours so as to achieve adsorption balance; adjusting the pH value of the solution to 4.5 in the shaking process; after adsorption equilibrium, the mixture was centrifuged by a centrifuge, and the supernatant was collected and the lead ion concentration C was measured at 283.3nm by atomic absorption spectrometry_e(ii) a Amount of adsorbed lead ion Q_eThe unit is mg/g,calculated from the following equation:

wherein V is the volume of the lead ion solution, and the unit is mL; m is the addition of the adsorbent, and the unit is mg; c₀And C_eThe initial concentration and the final concentration of the lead ion solution are respectively, and the unit is mg/L;

the pH value adopts 0.01-1moL/L HNO₃Adjusting by using a solution or 0.01-1moL/L NaOH solution; the centrifuge is a high-speed centrifuge with the rotating speed of 8000 r/min;

the preparation method of the adsorbent comprises the following steps:

first, WCl₆Dissolving in triethylene glycol, and adding glucose while stirring to obtain a uniform mixture; transferring the uniform mixture into a reaction kettle, heating to 200 ℃ and maintaining for 6 hours; after cooling, the nanowire net is collected by centrifugation, washed and freeze-dried to obtain the adsorbent;

WCl in said homogeneous mixture₆And the concentration of glucose is 17.5 g/L;

the freeze-drying is performed on the nanowire mesh obtained by centrifugal collection in a bulk tray dryer.

2. The application of the adsorbent for adsorbing the dye is characterized in that the adsorbent removes the dye by the following steps:

firstly, selecting a methylene blue solution as simulated dye wastewater; the adsorbent W is added₁₈O₄₉@ C to a concentration of C₀In methylene blue solution, W is treated by ultrasonic treatment for 5min₁₈O₄₉@ C is uniformly dispersed in the methylene blue solution, and then the mixed solution is put into a shaking table to be shaken for 24 hours so as to achieve adsorption balance; adjusting the pH value of the solution to 4.5 in the shaking process; after adsorption equilibrium, the mixture was centrifuged with a centrifuge, the supernatant was collected, and the concentration C of methylene blue was measured at 664nm by UV-visible absorption spectroscopy_e'; amount of adsorbed methylene blue Q_e', in mg/g, calculated from the following equation:

wherein V' is the volume of the methylene blue solution, and the unit is mL; m' is the addition of the adsorbent, and the unit is mg; c₀' and C_e' starting and final concentrations of methylene blue solution, respectively, in mg/L;

the pH value adopts 0.01-1moL/L HNO₃Adjusting by using a solution or 0.01-1moL/L NaOH solution; the centrifuge is a high-speed centrifuge with the rotating speed of 8000 r/min;

the preparation method of the adsorbent comprises the following steps:

first, WCl₆Dissolving in triethylene glycol, and adding glucose while stirring to obtain a uniform mixture; transferring the uniform mixture into a reaction kettle, heating to 200 ℃ and maintaining for 6 hours; after cooling, the nanowire net is collected by centrifugation, washed and freeze-dried to obtain the adsorbent;

WCl in said homogeneous mixture₆And the concentration of glucose is 17.5 g/L;

the freeze-drying is performed on the nanowire mesh obtained by centrifugal collection in a bulk tray dryer.

3. Use of the adsorbent according to claim 1 or 2, wherein the reaction vessel is a stainless steel reaction vessel lined with polytetrafluoroethylene.

4. Use of the adsorbent according to claim 1 or 2, wherein the washing is carried out with absolute ethanol and deionized water.

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