A polymethylpyrrole adsorbent for removing liquid phase Hg(II) and preparation method thereof

Abstract

The invention discloses a polymethylpyrrole adsorbent for removing liquid phase Hg(II) and a preparation method thereof, and belongs to the technical field of industrial wastewater purification and treatment. Ammonium persulfate is used as an initiator, and methylpyrrole monomer polymerization is initiated by chemical oxidation in an HCl solution. After vacuum filtration, washing, and drying, an efficient adsorbent for removing divalent mercury is obtained. The adsorbent has the advantages of simple preparation method, high removal efficiency, low cost, etc., and has good application prospects in the field of divalent mercury removal.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial wastewater purification and treatment, and specifically relates to a polymethylpyrrole adsorbent for removing liquid phase Hg(II) and a preparation method thereof. Background Art

[0002] At present, the commonly used methods for heavy metal wastewater treatment in my country include precipitation, adsorption, membrane separation, electrochemical method, etc. Chemical co-precipitation can remove heavy metal pollutants in water simply, economically and efficiently, and it can flexibly control the size and distribution of precipitated particles without affecting the composition, crystallinity and morphology of the precipitated particles. However, since a large amount of chemical reagents are added to the general chemical method, a large amount of difficult-to-treat waste residue is generated, which may cause a large amount of secondary pollution after chemical precipitation treatment. Therefore, its application in engineering and future sustainable development are still greatly hindered.

[0003] Membrane separation technology is a method of filtering by using the micropores of the membrane and separating certain substances in wastewater by using the selective permeability of the membrane. It has the advantages of high evaporation efficiency, low energy consumption, simple operation and no pollution. However, it also has disadvantages such as easy scaling, high preparation cost and the need for other equipment.

[0004] The redox method is to add highly oxidizing or highly reducing chemicals into the sewage to cause redox reactions between them and the pollutants in the water, thereby achieving the purpose of treating toxic and harmful pollutants in the sewage. At present, there are many derivative methods, such as Fenton oxidation, wet oxidation, ozone oxidation, electrochemical oxidation, etc., which have the advantages of simple process, fast reaction speed, high efficiency, and wide treatment range. However, it still has disadvantages such as poor stability and unsatisfactory secondary recovery treatment effect.

[0005] Among them, the adsorption method has the advantages of simple operation, low energy consumption, low investment cost and high efficiency. Adsorption is a simple and low-cost method. Traditional adsorbents such as activated carbon, zeolite and mesoporous silica have been used to capture Hg(II) from water. However, these traditional materials have weak adsorption capacity, slow kinetics, low adsorption capacity, poor regeneration ability and selectivity, which limits their application in mercury pollution remediation.

[0006] Therefore, it is necessary to prepare an efficient Hg(II) adsorbent with fast kinetics, high removal capacity, excellent selectivity and strong pH independence. Summary of the invention

[0007] The purpose of this section is to summarize some aspects of embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the specification abstract and the invention title of this application to avoid blurring the purpose of this section, the specification abstract and the invention title, and such simplifications or omissions cannot be used to limit the scope of the present invention.

[0008] In view of the above problems and / or the problems existing in the prior art, the present invention is proposed.

[0009] Therefore, the object of the present invention is to overcome the deficiencies in the prior art and provide a method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II).

[0010] In order to solve the above technical problems, the present invention provides the following technical solutions: comprising:

[0011] Adding the initiator solution dropwise to the 1-methylpyrrole monomer solution, stirring to carry out polymerization reaction after the addition is completed to obtain a polymethylpyrrole mixed solution, and then neutralizing, washing, and vacuum drying to obtain a polymethylpyrrole adsorbent;

[0012] Wherein, the volume mass ratio of the 1-methylpyrrole monomer to the initiator is 1-3 mL: 4-5 g.

[0013] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to the present invention, the initiator comprises ammonium persulfate.

[0014] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) of the present invention, the solvent of the 1-methylpyrrole monomer solution and the initiator solution is 0.1 mol / L hydrochloric acid solution.

[0015] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to the present invention, the dripping rate is 700-900 μL / min.

[0016] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to the present invention, the rotation speed of the polymerization reaction is 400 r / min and the reaction time is 4 h.

[0017] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to the present invention, the neutralization is performed by dropwise addition of 2 mol / L sodium hydroxide solution.

[0018] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) of the present invention, the washing is firstly washed twice with anhydrous ethanol and then washed with a large amount of deionized water until the pH of the filtrate is 5-7.

[0019] As a preferred embodiment of the method for preparing the polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to the present invention, the vacuum drying comprises the following steps: the drying temperature is 50 to 70° C. and the drying time is 10 to 15 hours.

[0020] Another object of the present invention is to overcome the deficiencies in the prior art and provide a polymethylpyrrole adsorbent.

[0021] The third object of the present invention is to overcome the deficiencies in the prior art and provide an application of a polymethylpyrrole adsorbent for removing Hg(II) in a liquid phase.

[0022] Adding polymethylpyrrole adsorbent to HgCl 2 In the aqueous solution, the polymethylpyrrole adsorbent is uniformly dispersed by stirring, and then allowed to stand for adsorption, and the removal efficiency of the polymethylpyrrole adsorbent for Hg(II) is measured;

[0023] Wherein, the HgCl 2 The concentration of the aqueous solution is 20 to 200 ppm, the pH is 3 to 11, and the adsorption time is 2 to 6 hours.

[0024] Beneficial effects of the present invention:

[0025] (1) The polymethylpyrrole adsorbent prepared by the present invention has a wide pH application range while ensuring a high adsorption and removal effect on Hg(II). In addition, the preparation method of the polymethylpyrrole adsorbent of the present invention involves a simple process, is non-toxic, and is environmentally friendly, and is suitable for promotion and application.

[0026] (2) The adsorbent synthesis method adopted by the present invention is simple to operate, has a simple process, and does not produce toxic by-products, which helps to achieve green chemistry and sustainable development.

[0027] (3) The adsorbent prepared by the present invention has a lower cost than conventional noble metal adsorbents, which makes it more economical in large-scale applications.

[0028] (4) The polymethylpyrrole powder synthesized in the present invention is a conductive polymer with a small particle size, a high specific surface area and abundant active sites, which helps to improve the adsorption capacity and efficiency of Hg(II) and is very suitable for the adsorption of liquid phase Hg(II), thereby greatly reducing the pollution of heavy metal mercury in the water environment.

[0029] (5) The present invention proposes a new type of Hg(II) adsorbent, which has good stability in water environment, is not easily affected by hydrolysis or other environmental factors, and has a very good adsorption effect; experimental tests show that the material has good adaptability to different pH conditions during the experiment, especially under the condition of pH = 7, the efficiency is higher than 95%, showing good adsorption; and under high concentration HgCl 2 Mercury removal experiments were carried out under aqueous solution conditions, and it also showed excellent ability to adsorb Hg(II).

[0030] (6) The present invention realizes the removal of Hg(II) by adsorption, and has the above-mentioned characteristics, so that the application range is wider, and the recovery and resource utilization of mercury are simpler and more efficient. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative labor. Among them:

[0032] Figure 1 The present invention is a flow chart of the preparation method of the polymethylpyrrole adsorbent.

[0033] Figure 2 The adsorption time of the adsorbent obtained in Example 1 of the present invention and the comparative example is the adsorption time of Hg by polymethylpyrrole 2+ The impact diagram of . DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and easy to understand, the specific implementation methods of the present invention are described in detail below in conjunction with the embodiments of the specification.

[0035] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein, and those skilled in the art may make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The term "in one embodiment" that appears in different places in this specification does not necessarily refer to the same embodiment, nor is it a separate or selective embodiment that is mutually exclusive with other embodiments.

[0037] Example 1

[0038] This embodiment provides a method for preparing a polymethylpyrrole adsorbent, specifically:

[0039] 1.85 mL of 1-methylpyrrole monomer was added to 50 mL of 0.1 mol / L hydrochloric acid solution, and the solution was stirred and evenly dispersed at a speed of 400 r / min to obtain a polymer pre-polymerization solution;

[0040] Weigh 4.61 g of ammonium persulfate solid, add it to 30 mL of 0.1 mol / L hydrochloric acid solution, stir and dissolve to obtain an ammonium persulfate solution as an initiator;

[0041] The mouth of the polymer pre-polymerization solution cup is sealed with a film, and the initiator ammonium persulfate solution is added dropwise into the polymer pre-polymerization solution at a rate of 800 μL / min through a peristaltic pump. After the ammonium persulfate solution is added, it is stirred at a speed of 400 r / min for 4 hours; the polymethylpyrrole mixed solution after the reaction is taken out, and then 30-32 mL of 2 mol / L sodium hydroxide solution is added dropwise to neutralize it; a vacuum filtration device is used to wash it twice with 50 mL of anhydrous ethanol, and then with a large amount of deionized water to wash it until the pH value of the filtrate is 7; the powder is vacuum dried at 60° C. for 12 hours to obtain a polymethylpyrrole adsorbent.

[0042] The Hg(II) removal efficiency of the polymethylpyrrole adsorbent prepared in this example was tested:

[0043] At room temperature (20-25°C), add polymethylpyrrole adsorbent to HgCl 2 The solution was stirred at 400 r / min for 2 h to disperse the solution evenly. The X-ray fluorescence heavy metal analyzer (test mode: water, test time: 100 s, solution volume: 100 mL, adsorbent dosage: 50 mg, temperature: room temperature) was used to measure the polymethylpyrrole adsorbent after immersion in HgCl for 2 h. 2 The results of the decrease in mercury salt concentration in the aqueous solution are shown in Table 1.

[0044] Table 1

[0045]

[0046]

[0047] It can be seen that under the same test conditions, the adsorption capacity of polymethylpyrrole powder synthesized by this method for Hg(II) is related to the pH and concentration of the mercury-containing solution. As can be seen from Table 1, under the same 20 ppm HgCl 2In aqueous solution, when the solution pH is 7, the mercury removal efficiency of polymethylpyrrole powder reaches the best, reaching 97.73% mercury removal efficiency in 2 hours, and the adsorption rate is fast; at 100ppm and 200ppm HgCl 2 In aqueous solution, the mercury removal efficiencies were 92.06% and 80.86%, respectively, indicating that they have excellent Hg(II) adsorption capabilities.

[0048] In summary, in view of the problem that the traditional method is still inefficient in removing Hg(II), the present invention proposes a polymethylpyrrole adsorbent for liquid phase Hg(II) and a preparation method thereof. The present invention is the first to use modified methylpyrrole powder for Hg 2+ adsorption.

[0049] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present invention may be modified or replaced by equivalents without departing from the spirit and scope of the technical solutions of the present invention, which should all be included in the scope of the claims of the present invention.

Claims

1. A method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II), characterized in that: include, Adding the initiator solution dropwise to the 1-methylpyrrole monomer solution, stirring to carry out polymerization reaction after the addition is completed to obtain a polymethylpyrrole mixed solution, and then neutralizing, washing, and vacuum drying to obtain a polymethylpyrrole adsorbent; Wherein, the volume mass ratio of the 1-methylpyrrole monomer to the initiator is 1-3 mL: 4-5 g.

2. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The initiator includes ammonium persulfate.

3. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The solvent of the 1-methylpyrrole monomer solution and the initiator solution is 0.1 mol / L hydrochloric acid solution.

4. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The dropping rate is 700-900 μL / min.

5. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The rotation speed of the polymerization reaction is 300-500 r / min, and the time is 3-5 hours.

6. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The neutralization is performed by dropwise addition of 2 mol / L sodium hydroxide solution.

7. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The washing step is to first wash twice with anhydrous ethanol and then wash with a large amount of deionized water until the pH value of the filtrate is 5-7.

8. The method for preparing a polymethylpyrrole adsorbent for removing liquid phase Hg(II) according to claim 1, characterized in that: The vacuum drying has a drying temperature of 50 to 70° C. and a drying time of 10 to 15 hours.

9. A polymethylpyrrole adsorbent for removing liquid phase Hg(II) prepared by the preparation method according to any one of claims 1 to 8.

10. Use of the polymethylpyrrole adsorbent as claimed in claim 9 for removing Hg(II) in liquid phase, characterized in that: include, Add the polymethylpyrrole adsorbent of claim 9 to a HgCl2 aqueous solution, stir to evenly disperse the polymethylpyrrole adsorbent, allow to stand for adsorption, and measure the Hg(II) removal efficiency of the polymethylpyrrole adsorbent; Wherein, the concentration of the HgCl2 aqueous solution is 20-200 ppm, the pH is 3-11, and the adsorption time is 2-6 hours.

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