CN108816201B

CN108816201B - Silver ion adsorption material and preparation method and application thereof

Info

Publication number: CN108816201B
Application number: CN201810662872.2A
Authority: CN
Inventors: 罗旭彪; 殷晓翠
Original assignee: Nanchang Hangkong University
Current assignee: Nanchang Hangkong University
Priority date: 2018-06-25
Filing date: 2018-06-25
Publication date: 2021-03-12
Anticipated expiration: 2038-06-25
Also published as: CN108816201A

Abstract

The invention provides a preparation method of a silver ion adsorption material, which comprises the steps of firstly, mixing a rhodanine derivative monomer, N' -methylene bisacrylamide, a thermal initiator and a polar organic solvent under the protection of nitrogen or inert gas to obtain a raw material mixture; the rhodanine derivative monomer is 3-allyl rhodanine or 3-butenyl rhodanine; then, thermal polymerization was performed while maintaining the atmosphere protected by nitrogen or inert gas, thereby obtaining a silver ion-adsorbing material. The silver ion adsorbing material prepared by the preparation method provided by the invention can be used for treating strong acid wastewater with the pH value of 0.18, and the adsorption capacity of the silver ion adsorbing material can reach 389.4mg/g when the initial concentration of silver ions is 420mg/L, namely, the silver ion adsorbing material still maintains higher adsorbability under the condition of strong acid.

Description

Silver ion adsorption material and preparation method and application thereof

Technical Field

The invention relates to the technical field of heavy metal adsorption materials, in particular to a silver ion adsorption material and a preparation method and application thereof.

Background

Silver is a silvery-white transition metal. It is very ductile and has the highest electrical and thermal conductivity of all metals. Silver is commonly used to make physical instrument elements with extremely high sensitivity, and electronic and electric appliances are the industries with the largest silver consumption, and the use of the silver is divided into electric contact materials, composite materials and welding materials. Among silver compounds, silver halide photosensitive materials are one of the largest areas in which silver is used, and several photosensitive materials which are currently produced and sold in the largest quantities are photographic films, photographic papers, X-ray films, fluorescent information recording films, electron microscope photographic films, printing films, and the like. Furthermore, two main applications of silver in chemical engineering are: one is silver catalysts, such as are widely used in redox and polymerization reactions, for treating industrial waste gases containing sulfides, etc.; the other is an electronic electroplating industrial preparation, such as silver paste, silver potassium cyanide and the like. Because the silver-containing products are widely applied, the products can generate a large amount of silver-containing wastes after preparation, use and abandonment, and the silver-containing wastes cannot be recycled, thereby causing a large amount of resource waste. Silver ions are more harmful to human bodies when entering the environment. Silver ions react with hemoglobin to denature proteins and various enzymes of the human body, and more than 0.8g of silver ions introduced into the body cause blue silver plaque precipitation on the skin. Since silver ions are highly oxidative, the silver ions introduced into the human body also cause symptoms such as organ edema, and in severe cases, cause death. The human body has no effective silver-expelling mechanism, so once the silver ions are taken in, the silver ions are mainly accumulated in the bones and the liver. Silver ions are used as heavy metal ions and are precious metals, and the selective removal and recovery of the silver ions have important significance and economic value.

Recovery of Ag from waste water⁺The traditional methods of (A) include precipitation, electrolysis, ion exchange, membrane separation, adsorption. In the method, the adsorption is a technology with great development prospect due to simple operation, low energy consumption and high efficiency. Many methods have been developed for separating and recovering Ag⁺Including modified silica nanoparticles, activated carbon, spent coffee grounds, chelating resins, ion imprinted polymers, and the like. However, the above adsorbent has a drastically decreased adsorption amount at a wastewater pH of less than 4, and cannot be used for adsorbing silver ions in strongly acidic wastewater.

Disclosure of Invention

The invention aims to provide a silver ion adsorbing material, and a preparation method and application thereof.

In order to achieve the above object, the present invention provides the following technical solutions:

a preparation method of a silver ion adsorption material comprises the following steps:

(1) under the protection of nitrogen or inert gas, mixing a rhodanine derivative monomer, N' -methylene bisacrylamide, a thermal initiator and a polar organic solvent to obtain a raw material mixture; the rhodanine derivative monomer is 3-allyl rhodanine or 3-butenyl rhodanine;

(2) and maintaining the atmosphere protected by nitrogen or inert gas, and carrying out thermal polymerization reaction to obtain the silver ion adsorbing material.

Preferably, the molar ratio of the rhodanine derivative monomer to the N, N' -methylene bisacrylamide is 1: 0.2-1.

Preferably, the molar ratio of the rhodanine derivative monomer to the thermal initiator is 1: 0.3-0.5.

Preferably, the thermal initiator is azobisisobutyronitrile.

Preferably, the polar organic solvent is at least one of methanol and N, N-dimethylformamide.

Preferably, the ratio of the amount of the rhodanine derivative monomer to the volume of the polar organic solvent is 1mmol: 8-12 mL.

Preferably, the temperature of the thermal polymerization reaction is 55-65 ℃, and the time of the thermal polymerization reaction is 2.5-3.5 h.

The invention also provides a silver ion adsorbing material prepared by the preparation method of the technical scheme.

The invention also provides an application of the silver ion adsorbing material in selective removal of silver ions, which comprises the following steps:

mixing a silver ion adsorbing material with wastewater to be treated, oscillating and adsorbing for 5-8 h at an oscillation speed of 150-250 rpm, and then carrying out solid-liquid separation to obtain a treated water body.

Preferably, the ratio of the mass of the silver ion adsorbing material to the volume of the wastewater to be treated is 1g: 800-1500 mL.

The invention provides a preparation method of a silver ion adsorption material, which comprises the following steps of firstly, mixing a rhodanine derivative monomer, N' -methylene bisacrylamide, a thermal initiator and a polar organic solvent under the protection of nitrogen or inert gas to obtain a raw material mixture; the rhodanine derivative monomer is 3-allyl rhodanine or 3-butenyl rhodanine; then, thermal polymerization was performed while maintaining the atmosphere protected by nitrogen or inert gas, thereby obtaining a silver ion-adsorbing material. The invention carries out thermal polymerization reaction on the rhodanine derivative monomer and N, N' -methylene bisacrylamide to obtain the copolymer with higher polymerization degree, the obtained copolymer has higher stability and strong acid resistance, and the copolymer contains a large amount of polymer

Functional and imino groups, may beThe selective adsorption of silver ions is realized. Experimental results show that the silver ion adsorbing material prepared by the preparation method can be used for treating strong acid wastewater with the pH value of 0.18, and the adsorption capacity of the silver ion adsorbing material can reach 389.4mg/g when the initial concentration of silver ions is 420mg/L, namely, the silver ion adsorbing material still maintains high adsorbability under the strong acid condition.

Drawings

FIG. 1 is a scanning electron microscope image of a silver ion-adsorbing material obtained in example 1.

Detailed Description

The invention provides a preparation method of a silver ion adsorbing material, which comprises the following steps:

In the invention, under the protection of nitrogen or inert gas, a rhodanine derivative monomer, N' -methylene bisacrylamide, a thermal initiator and a polar organic solvent are mixed to obtain a raw material mixture.

The mixing sequence of the rhodanine derivative monomer, the N, N' -methylene bisacrylamide, the thermal initiator and the polar organic solvent is not particularly limited, and can be any mixing sequence. In the embodiment of the present invention, the raw materials are preferably mixed in order by adding the rhodanine derivative monomer, N' -methylenebisacrylamide, and the thermal initiator to the polar organic solvent in this order.

According to the invention, the polar organic solvent is preferably added into the container, and then the vacuum-pumping treatment and the nitrogen or inert gas introduction are sequentially carried out to obtain the condition of nitrogen or inert gas protection.

In the present invention, the pressure of the vacuuming treatment is preferably-0.06 to-0.1 MPa, and more preferably-0.07 to-0.08 MPa. In the invention, the vacuumizing treatment can pump out the gas in the container and the solvent, and then the nitrogen or inert gas is filled in the container and the solvent, so that the solvent can be ensured to be in an oxygen-free environment, and the subsequent raw materials are prevented from being oxidized.

In the present invention, the pressure of the nitrogen or inert gas blanket is preferably normal pressure.

In the present invention, the polar organic solvent is preferably at least one of methanol and N, N-dimethylformamide.

In the present invention, the ratio of the amount of the rhodanine derivative monomer to the volume of the polar organic solvent is preferably 1mmol:8 to 12mL, and more preferably 1mmol:9 to 11 mL.

After the protection condition of nitrogen or inert gas is obtained, the invention preferably adds the rhodanine derivative monomer, the N, N' -methylene bisacrylamide and the thermal initiator into the polar organic solvent in sequence to obtain a raw material mixture.

In the present invention, the rhodanine derivative monomer is 3-allylrhodanine or 3-butenylrhodanine.

In the invention, the molar ratio of the rhodanine derivative monomer to the N, N' -methylene bisacrylamide is preferably 1: 0.2-1, and more preferably 1: 0.5-0.8. In the invention, the rhodanine derivative monomer and N, N' -methylene bisacrylamide are subjected to thermal polymerization to obtain a copolymer with a higher polymerization degree, so that the stability of the adsorbing material is improved, and the rhodanine derivative monomer can still be used under a strong acid condition.

In the invention, the molar ratio of the rhodanine derivative monomer to the thermal initiator is preferably 1: 0.3-0.5, and more preferably 1: 0.4.

In the present invention, the thermal initiator is preferably azobisisobutyronitrile (abbreviated as AIBN).

In the present invention, it is preferable that after the rhodanine derivative monomer, the N, N' -methylenebisacrylamide and the thermal initiator are added, the vacuum treatment and the introduction of nitrogen or inert gas are sequentially performed. In the invention, after all the materials are added, the operations of vacuumizing and introducing nitrogen or inert gas can remove oxygen introduced into the system in the feeding process, thereby ensuring that the reaction is in an anaerobic state.

In the present invention, the operations of vacuum-pumping and introducing nitrogen or inert gas after all the materials are added are the same as the operations of vacuum-pumping and introducing nitrogen or inert gas when the polar organic solvent is added, and the details are not repeated herein.

The invention preferably maintains the stirring state in the feeding process; the invention has no special limit on the rotating speed and the time of stirring, and can stir the system uniformly.

In the present invention, the thermal initiator is preferably added rapidly. The rapid addition of the thermal initiator is beneficial to reducing the contact time of the thermal initiator and air and reducing the deterioration of the thermal initiator as much as possible,

after the raw material mixture is obtained, the invention maintains the atmosphere protected by nitrogen or inert gas, and carries out thermal polymerization reaction to obtain the silver ion adsorbing material.

The invention preferably adopts a slow heating mode to heat the raw material mixture to the temperature required by the thermal polymerization reaction. In the invention, the slow temperature rise can avoid the reaction rate from rising too fast, thereby avoiding the occurrence of implosion caused by reaction runaway. In the invention, the heating rate of the slow heating is preferably 2-5 ℃/min.

In the invention, the temperature of the thermal polymerization reaction is preferably 55-65 ℃, and more preferably 58-62 ℃; the time of the thermal polymerization reaction is preferably 2.5-3.5 hours, and more preferably 2.8-3.2 hours; the time of the thermal polymerization reaction is preferably from when the temperature reaches the temperature required for the thermal polymerization.

After the thermal polymerization reaction is completed, the mixture obtained by the thermal polymerization reaction is preferably filtered, washed and dried in sequence to obtain the silver ion adsorbing material.

In the present invention, the washing solvent is preferably methanol; the washing frequency is preferably 3-5 times; the ratio of the volume of the solvent to the mass of the solid for each washing is 50mL: 0.2-0.5 g.

The washing mode is not particularly limited, and a conventional washing mode can be adopted. In the embodiment of the invention, the washing is preferably carried out by mixing a solvent for washing with the solid product to be washed, stirring for 10-15min, and then filtering to complete one washing.

The drying mode is not particularly limited, and the product with constant weight can be obtained. In the embodiment of the present invention, the drying is preferably air-blast drying; the drying temperature is preferably 50-70 ℃; the drying time is preferably 4-6 h.

After the drying is finished, the product obtained by drying is preferably ground to obtain the silver ion adsorbing material.

In the invention, the particle size of the silver ion adsorbing material is preferably 1-1.5 μm, and more preferably 1.2-1.4 μm.

In the invention, the ratio of the mass of the silver ion adsorbing material to the volume of the wastewater to be treated is preferably 1g: 800-1500 mL.

In the present invention, the solid-liquid separation is preferably centrifugal separation; the rotation speed of the centrifugation is preferably 6000-9000 rpm; the time for centrifugation is preferably 3-5 min.

The silver ion adsorbing material, the preparation method and the application thereof provided by the present invention will be described in detail with reference to the following examples, but they should not be construed as limiting the scope of the present invention.

Example 1

(1) Adding 50mL of methanol into a 100mL flask, vacuumizing to-0.08 MPa, introducing nitrogen, adding 5mmol (0.8663 g) of 3-allyl rhodanine under stirring, and dissolving completely to obtain a transparent bright yellow solution (3-allyl rhodanine solution);

(2) adding 1mmol (0.1542 g) of N, N' -methylene bisacrylamide to the 3-allylrhodanine solution, and stirring to dissolve; then quickly adding 2mmol (0.3284 g) AIBN, vacuumizing to-0.07 MPa, introducing nitrogen, and uniformly stirring to obtain a raw material mixture;

(3) under the protection of nitrogen, heating to 60 ℃ at the heating rate of 3 ℃/min, and carrying out condensation reflux reaction for 3 h;

(4) cooling the mixture obtained by the reaction to room temperature, and then performing suction filtration and separation to obtain a solid product; washing the solid product with methanol for three times, wherein the time of each washing and stirring is 10 min; and drying the washed solid product at 60 ℃, and grinding to obtain the silver ion adsorbing material.

The silver ion adsorbing material obtained in this example was characterized by using a scanning electron microscope, and the result is shown in fig. 1, and it can be seen from fig. 1 that the silver ion adsorbing material obtained in this example is spherical particles, and the average particle size thereof is 1.2 μm.

Example 2

(1) Adding 50mL of methanol into a 100mL flask, vacuumizing to-0.09 MPa, introducing nitrogen, adding 5mmol (0.8663 g) of 3-allyl rhodanine under stirring, and dissolving completely to obtain a transparent bright yellow solution (3-allyl rhodanine solution);

(2) adding 3mmol (0.4626 g) of N, N' -methylene bisacrylamide to the 3-allylrhodanine solution, and stirring to dissolve; then quickly adding 2mmol (0.3284 g) AIBN, vacuumizing to-0.09 MPa, introducing nitrogen, and uniformly stirring to obtain a raw material mixture;

(4) cooling the mixture obtained by the reaction to room temperature, and then performing suction filtration and separation to obtain a solid product; washing the solid product with methanol for three times, wherein the time of each washing and stirring is 15 min; and drying the washed solid product at 60 ℃, and grinding to obtain the silver ion adsorbing material.

The silver ion adsorbing material obtained in this example was characterized by a scanning electron microscope, and the result is similar to fig. 1, and the silver ion adsorbing material obtained in this example was spherical particles, and the average particle size was measured to be 1.3 μm.

Example 3

(1) Adding 30mLN, N-dimethylformamide and 60mL methanol into a 100mL flask, vacuumizing to-0.1 MPa, introducing nitrogen, adding 10mmol (1.7326 g) of 3-allylrhodanine under stirring, and dissolving completely to obtain a transparent bright yellow solution (3-allylrhodanine solution);

(2) adding 2mmol (0.3083 g) of N, N' -methylene bisacrylamide to the 3-allylrhodanine solution, and stirring to dissolve; then quickly adding 2mmol (0.3284 g) AIBN, vacuumizing to-0.1 MPa, introducing nitrogen, and uniformly stirring to obtain a raw material mixture;

(3) under the protection of nitrogen, heating to 60 ℃ at the heating rate of 2 ℃/min, and carrying out condensation reflux reaction for 3 hours;

The silver ion adsorbing material obtained in this example was characterized by a scanning electron microscope, and the result is similar to fig. 1, and the silver ion adsorbing material obtained in this example was spherical particles, and the average particle size was measured to be 1.2 μm.

Example 4

(1) Adding 30mL LN, N-dimethylformamide and 60mL methanol into a 100mL flask, vacuumizing to-0.1 MPa (pressure), introducing nitrogen, adding 5mmol (0.935 g) of 3-butenyl rhodanine under stirring, and dissolving completely to obtain a transparent bright yellow solution, namely a 3-butenyl rhodanine solution;

(2) adding 2mmol (0.3083 g) of N, N' -methylene bisacrylamide to the 3-butenyl rhodanine solution, and stirring to dissolve; then quickly adding 2mmol (0.3284 g) AIBN, vacuumizing to-0.1 MPa, introducing nitrogen, and uniformly stirring to obtain a raw material mixture;

Example 5

Respectively putting 20mg of the silver ion adsorbing materials obtained in the embodiments 1-3 into 20mL of mixed heavy metal solution containing Ag⁺、Co²⁺、Ni²⁺、Pb²⁺And Cu²⁺The concentration of the obtained solution is 5mmol/L, and the obtained system is subjected to oscillation adsorption for 6 hours in a constant temperature oscillation box under the condition of 25 ℃ and the oscillation speed of 180 rpm; and centrifuging at the rotating speed of 6000-9000 rpm for 3-5 min, and taking a clarified liquid to obtain the treated water body.

The concentration of each ion in the treated water body was measured by a flame atomic absorption method, and the amount of each ion adsorbed by the silver ion adsorbing material was calculated, and the results are shown in table 1. As can be seen from Table 1, the silver ion-adsorbing materials obtained in examples 1 to 4 have selective adsorbability to silver ions, and the adsorbability can reach 368.5 mg/g.

TABLE 1 adsorption Performance of silver ion adsorbing materials measured in examples 1 to 4

Example 6

Respectively putting 20mg of the silver ion adsorbing materials obtained in the embodiments 1 to 4 into 20mL of silver ion solutions with the concentration of 420mg/L, and adopting HNO₃Adjusting the pH value of the mixed heavy metal solution to 0.18; carrying out oscillation adsorption on the obtained system in a constant-temperature oscillation box for 6 hours at 25 ℃ and an oscillation speed of 180 rpm; and centrifuging at the rotating speed of 6000-9000 rpm for 3-5 min, and taking a clarified liquid to obtain the treated water body.

The concentration of ions in the treated water body was measured by a flame atomic absorption method, and the amount of silver ions adsorbed by the silver ion adsorbing material was calculated, with the results shown in table 2.

The silver ion solution was treated by changing the pH in the above manner, and the adsorption performance of the silver ion-adsorbing material to silver ions was measured, and the results are shown in table 2.

The results are shown in Table 2. As can be seen from Table 2, the silver ion adsorbing materials obtained in examples 1 to 4 have strong adsorption performance on silver ions within a pH range of 0.18 to 5.38.

Table 2 adsorption Performance of silver ion adsorbing Material measured in examples 1 to 4

Example 7

Respectively putting 20mg of the silver ion adsorbing materials obtained in the embodiments 1-4 into 20mL of mixed heavy metal solution containing Ag⁺、Co²⁺、Ni²⁺、Pb²⁺And Cu²⁺The concentration of (A) is 500mg/L, HNO is adopted₃Adjusting the pH value of the mixed heavy metal solution to 0.18; carrying out oscillation adsorption on the obtained system in a constant-temperature oscillation box for 6 hours at 25 ℃ and an oscillation speed of 180 rpm; and centrifuging at the rotating speed of 6000-9000 rpm for 3-5 min, and taking a clarified liquid to obtain the treated water body.

The concentration of each ion in the treated water body was measured by a flame atomic absorption method, and the amount of each ion adsorbed by the silver ion adsorbing material was calculated, and the results are shown in table 3. As can be seen from Table 3, under the acidic condition of pH value of 0.18, the silver ion adsorbing material provided by the invention still has strong selectivity to silver ions and has high adsorption capacity, which can reach 378.5 mg/g.

Table 3 Selective adsorption of silver ion adsorbing materials tested in examples 1 to 4 under acidic conditions

The foregoing is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. A preparation method of a silver ion adsorption material comprises the following steps:

(1) under the protection of nitrogen or inert gas, mixing a rhodanine derivative monomer, N' -methylene bisacrylamide, a thermal initiator and a polar organic solvent to obtain a raw material mixture; the rhodanine derivative monomer is 3-allyl rhodanine or 3-butenyl rhodanine; the molar ratio of the rhodanine derivative monomer to the N, N' -methylene bisacrylamide is 1: 0.2-1;

(2) maintaining the atmosphere protected by nitrogen or inert gas, and carrying out thermal polymerization reaction to obtain a silver ion adsorbing material; the temperature of the thermal polymerization reaction is 55-65 ℃, and the time of the thermal polymerization reaction is 2.5-3.5 h.

2. The preparation method of claim 1, wherein the molar ratio of the rhodanine derivative monomer to the thermal initiator is 1: 0.3-0.5.

3. The method according to claim 1 or 2, wherein the thermal initiator is azobisisobutyronitrile.

4. The method according to claim 1, wherein the polar organic solvent is at least one of methanol and N, N-dimethylformamide.

5. The method according to claim 1 or 4, wherein the ratio of the amount of said rhodanine derivative monomer substance to the volume of the polar organic solvent is 1mmol: 8-12 mL.

6. A silver ion adsorbing material prepared by the preparation method of any one of claims 1 to 5.

7. Use of the silver ion adsorbent material of claim 6 for selective removal of silver ions, comprising the steps of:

8. The application of claim 7, wherein the ratio of the mass of the silver ion adsorbing material to the volume of the wastewater to be treated is 1g: 800-1500 mL.