CN107812509A - A kind of filter membrane material and its preparation method and application - Google Patents

Abstract

The present invention relates to the technical field of filter materials, and discloses a method for preparing a filter membrane material. The method includes: dissolving transition metal salt in a solvent, forming a solution, adding a carbon film, mixing evenly, and adding to a high-pressure Carry out the reaction in the reactor. After the high-pressure reactor is evacuated, CO ₂ is filled until the internal absolute pressure is 80~150bar, and the temperature is raised to 35~60 ^o C to start the reaction. After 0.5~24h of reaction, CO ₂ is released. to normal pressure, and cooled to room temperature to obtain the reaction kettle liquid, and dry to obtain a precursor carbon film. Under the protective gas atmosphere, react the precursor carbon film at 700-1000°C for 2-8 hours to obtain a transition metal / carbon composite membrane, immersed in the CS2 solution of sulfur, after soaking for ₁ ~ 12h, filter and dry to obtain the filter membrane material; the filter membrane material prepared by the present invention has uniform transition metal loading, good consistency, and high With the characteristics of adsorption efficiency and high adsorption capacity, the filter membrane material is easy to separate from water, easy to recycle, and suitable for industrial production.

Description

A kind of filter membrane material and its preparation method and application

technical field

The invention relates to the technical field of filter materials, in particular to a filter membrane material and its preparation method and application.

Background technique

my country's total mercury consumption is about 1,000 tons, accounting for about 50% of the world's total consumption, and it is the world's largest consumer and producer. However, mercury is highly neurotoxic, can enter organisms through various channels, and is difficult to metabolize, so it causes cumulative effects in organisms and poses a huge threat to human health. Therefore, the prevention and control of mercury pollution is urgent.

So far, the treatment technologies for mercury-containing wastewater mainly include chemical methods, electrolysis methods, ion exchange methods, and adsorption methods. Among them, adsorption method is the most common technical method in mercury removal technology. Mercury removal adsorbents mainly include carbon-based adsorbents, oxide-based adsorbents, ore-based adsorbents, and precious metal-based adsorbents. From the perspective of the actual mercury removal effect, carbon-based adsorbents are the most mature, efficient, and cheap mercury removal adsorbents because of their developed pore structure, large surface area, and abundant surface functional groups. However, most of the untreated carbon-based adsorbents belong to physical adsorption, which can provide less active sites for mercury, resulting in lower mercury removal efficiency. Therefore, the adsorbents currently used to remove mercury ions in water mainly have the following problems: (1) The capacity of the adsorbent is limited; (2) The selectivity is poor; (3) The adsorbent is mostly powder, which is not easy to separate from water. Recycling is difficult. Therefore, it is necessary to develop high-efficiency adsorbents with high adsorption capacity, high selectivity and easy recovery.

Contents of the invention

To solve the above problems, the present invention provides a filter membrane material and a preparation method thereof.

The technical solution adopted by the present invention to solve its technical problems is:

A preparation method of filter membrane material is characterized in that the method comprises the following steps:

(1) Dissolve the transition metal salt in the solvent, and form a solution after dissolving evenly;

(2) Add a carbon film to the 10-60ml solution obtained in step (1), mix well, add it to a 100ml autoclave for reaction, evacuate the autoclave to a vacuum of 0.01~0.1MPa, and fill it with CO _2. The absolute pressure inside the autoclave is 8~15MPa, and the temperature is raised to 35~60 ^o C to start the reaction. After reacting for 0.5~24h, the _CO in the autoclave is released to normal pressure, and cooled to room temperature to obtain the autoclave liquid;

(3) Evaporate the reaction kettle liquid, evaporate the solvent, and dry the remaining solid to obtain the precursor carbon film;

(4) Under a protective gas atmosphere, react the precursor carbon film at a reaction temperature of 700-1000° C. for 2-8 hours to obtain a transition metal/carbon composite film;

(5) Immerse the transition metal/carbon composite membrane in 10ml of sulfur-containing CS ₂ solution, soak for 1-12 hours, filter, and dry to obtain the filter membrane material.

Preferably, the transition metal salt is one or more of iron, cobalt, nickel, manganese, copper, zinc sulfate, nitrate or chloride salt, and the transition metal salt becomes a transition metal through the steps of the above preparation method Elemental substance, with strong reducibility, can reduce mercury ions to mercury elemental substance.

Preferably, the solvent is at least one of water, ethanol, and isopropanol. The solvent can dissolve the transition metal salt well to form a uniform solution, and the transition metal salt can be hydrolyzed in the solvent.

Preferably, in the step (1), the molar concentration of the transition metal salt in the solution is 0.01-1 mol/L.

As a preference, in the step (2), the carbon film is at least one of carbon paper, carbon cloth, and carbon fiber, the added mass is 0.5-10 g, and the carbon film is several millimeters to several centimeters in size, which can be block Or flake, which can be in the shape of sphere, rectangle, circle, irregular polygon, etc., and the carbon film is used as a carrier to provide active sites for the transition metal element and sulfur element.

Preferably, in the step (4), the protective gas is at least one of Ar, H ₂ , and N ₂ , and the transition metal in the precursor carbon film exists in the form of hydroxide. Under high temperature conditions, the carbon The membrane reduces it to transition metal simple substance, and the protective gas is to prevent the reduced transition metal simple substance from being oxidized.

Preferably, in the step (4), the reaction temperature is preferably 750-900 ^o C, and the reaction time is preferably 2-4 hours.

Preferably, in the step (5), in the sulfur CS ₂ solution, the mass volume ratio of sulfur to CS ₂ is 1-50:100 g/mL, and the sulfur has the function of adsorbing simple mercury.

The present invention also provides the filter membrane material prepared by the above method.

The present invention also provides the application of the above filter membrane material in removing mercury ions in liquid.

When the high-pressure reactor of the present invention reacts, the function of _CO2 is to provide a medium in a supercritical state. In the supercritical state, the transition metal salt solution and the carbon film are in better contact with each other.

The useful effects of the present invention are: (1) The present invention uses the strong reducibility of transition metals to reduce mercury ions by loading transition metal simple substances on the carbon film, and then fixes the mercury ions in the aqueous solution on the carbon membrane through the chemical adsorption of sulfur. On the membrane, so as to realize the purification of mercury sewage, the filter membrane material has excellent mercury ion adsorption performance, the material has high selectivity for removing mercury ions, and can be widely used in the field of mercury ion wastewater treatment; (2) The obtained filter membrane material, the transition metal load is uniform, the consistency is good, and the mercury adsorption sites can be adjusted on the filter membrane material, which has high adsorption efficiency and high adsorption capacity; (3) the filter membrane material is easy to separate from water and easy to recycle.

Description of drawings

The accompanying drawings are used to provide a further understanding of the present invention, and constitute a part of the description, and are used together with the following specific implementation methods to explain the present invention, but do not constitute a limitation to the present invention. In the attached picture:

Fig. 1 is the XRD picture of the product obtained in embodiment 1.

Fig. 2 is the mercury adsorption capacity curve of the product obtained in embodiment 1.

Fig. 3 is the XRD photo of the product obtained in embodiment 2.

Detailed ways

The technical solutions of the present invention will be further specifically described below through specific embodiments and in conjunction with the accompanying drawings.

Example 1

Take 0.98g NiCl ₂ ·6H ₂ O, dissolve in 30ml of absolute ethanol, dissolve evenly to form a solution, add 3g carbon cloth to the above solution, mix evenly, and put them into a 100mL autoclave for reaction. After the autoclave is evacuated to a vacuum of 0.1 MPa, CO ₂ gas is filled to make the absolute pressure inside the autoclave reach 9 MPa. After reacting at 40°C for 0.5 h, the CO ₂ in the autoclave is released to normal pressure, and cooled to room temperature to obtain the reaction kettle liquid; the solvent in the reaction kettle liquid was volatilized under vacuum, and the remaining solid was dried, placed under an argon protective gas atmosphere, and heated at a rate of 5 °C/min The rate was increased to 800°C, the calcination time was 2h, and the nickel/carbon composite membrane material was obtained after cooling. Weigh 0.3g of sulfur and dissolve it in 10ml of carbon disulfide to form a carbon disulfide solution of sulfur, immerse the above-mentioned nickel/carbon composite membrane material in the above-mentioned carbon disulfide solution of sulfur, soak for 6 hours, evaporate carbon disulfide, and dry to obtain the filter membrane material. Its XRD spectrum is shown in Figure 1.

Using the filter membrane material obtained in Example 1, the mercury adsorption experiment was carried out under the following conditions: HgCl ₂ was used as the mercury source, and 20 ml of mercury solution with a mercury ion concentration of 50 mg L ^-1 was prepared as the simulated mercury sewage.

The mercury adsorption experiment was carried out with the prepared filter membrane material. The test condition was that the prepared filter membrane material was immersed in the configured mercury sewage solution at room temperature. The adsorption efficiency of the adsorbent material reached 83% within 5 minutes. %, the adsorption efficiency of mercury ions reached 98% after 30 minutes, and the mercury adsorption capacity curve of the filter membrane material is shown in Figure 2.

Example 2

Take 0.02g NiCl ₂ ·6H ₂ O, dissolve in 10ml water, dissolve evenly to form a solution, add 0.5g carbon paper to the above solution, mix evenly, put them into a 100mL autoclave for reaction, wait for high pressure After the reactor was evacuated to a vacuum of -0.05MPa, CO ₂ gas was filled, and the absolute pressure inside the autoclave reached 8 MPa. After reacting at 60°C for 24 hours, the CO ₂ in the autoclave was released to normal pressure, and cooled to room temperature to obtain the reaction kettle liquid; after the reaction kettle liquid was fully dried, it was placed under an argon protective gas atmosphere and raised to 900 °C at a heating rate of 5 °C/min, and the calcination time was 3 hours. After cooling, A nickel/carbon composite membrane material is obtained. Weigh 0.1g of sulfur and dissolve it in 10ml of carbon disulfide to form a carbon disulfide solution of sulfur, immerse the above-mentioned nickel/carbon composite membrane material in the above-mentioned carbon disulfide solution of sulfur, soak for 1 hour, evaporate carbon disulfide, and dry to obtain the filter membrane material. Its XRD pattern is shown in Figure 3.

The mercury adsorption experiment was carried out with the prepared filter membrane material. The test condition was that the prepared filter membrane material was immersed in the configured mercury sewage solution at room temperature. The adsorption efficiency of the adsorption material for mercury ions reached 80% within 5 minutes. %, and the mercury ion adsorption efficiency reached 97% after 40 min.

Example 3

Take 6.48g of FeCl ₃ , dissolve it in 40ml of absolute ethanol, and dissolve it evenly to form a solution. Add 10g of carbon fiber to the above solution, mix it evenly, add it to a 100mL autoclave for reaction, and wait until the autoclave is evacuated After the temperature reaches 0.1MPa, fill in _CO2 gas, and make the absolute pressure inside the autoclave reach 15 MPa. After reacting at 50°C for 6h, release the _CO2 in the autoclave to normal pressure, and cool to At room temperature, the reaction kettle liquid was obtained; after the reaction kettle liquid was fully dried, it was placed under an argon protective gas atmosphere and raised to 1000 °C at a rate of 5 °C/min, calcined for 4 hours, and an iron/carbon composite film was obtained after cooling Material. Weigh 5g of sulfur and dissolve it in 10ml of carbon disulfide to form a sulfur carbon disulfide solution. Immerse the iron/carbon composite membrane material in the above-mentioned sulfur carbon disulfide solution. After soaking for 8 hours, volatilize the carbon disulfide and dry to obtain the filter membrane material.

The mercury adsorption experiment was carried out with the prepared filter membrane material. The test condition was that the prepared filter membrane material was immersed in the configured mercury sewage solution at room temperature. The adsorption efficiency of the adsorption material for mercury ions reached 90% within 3 minutes. %, and the mercury ion adsorption efficiency reached 99% after 20 min.

Example 4

Take 3.25g Fe(NO ₃ ) ₃ 9H ₂ O, dissolve it in 35ml water, dissolve evenly to form a solution, add 2.5g carbon fiber to the above solution, mix evenly, put them into a 100mL autoclave for reaction After the autoclave is evacuated to a vacuum of 0.01 MPa, CO ₂ gas is charged to make the absolute pressure inside the autoclave reach 10 MPa. After reacting at 35°C for 12 hours, release the _CO in the autoclave to normal pressure, and cool to room temperature to obtain the autoclave liquid; after fully drying the autoclave liquid, place it under a nitrogen protective gas atmosphere to The heating rate was increased to 750 °C at a rate of 5 °C/min, the calcination time was 8 h, and the iron/carbon composite membrane material was obtained after cooling. Weigh 2.0g of sulfur and dissolve it in 10ml of carbon disulfide to form a carbon disulfide solution of sulfur. Immerse the iron/carbon composite membrane material in the carbon disulfide solution of sulfur. After soaking for 12 hours, volatilize the carbon disulfide and dry it to obtain the filter membrane material.

The mercury adsorption experiment was carried out with the prepared filter membrane material. The test condition was that the prepared filter membrane material was immersed in the configured mercury sewage solution at room temperature. The adsorption efficiency of the adsorbent material reached 92% within 3 minutes. %, and the mercury ion adsorption efficiency reached 99% after 15 minutes.

The embodiment described above is only a preferred solution of the present invention, and does not limit the present invention in any form. There are other variations and modifications on the premise of not exceeding the technical solution described in the claims.

Claims (10)

1. a kind of preparation method of filter membrane material, it is characterised in that this method comprises the following steps：（1）By transition metal salt It is dissolved in solvent, solution is formed after being uniformly dissolved；（2）Take step（1）Obtained solution 10-60ml, carbon film is added, be well mixed Afterwards, it is added in 100ml autoclaves and is reacted, after being 0.01 ~ 0.1MPa by autoclave degree of being evacuated, is filled with CO₂Absolute pressure is 8 ~ 15MPa inside to autoclave, is warming up to 35 ~ 60^oC, start to react, after reacting 0.5 ~ 24h, discharge high pressure CO in reactor₂To normal pressure, and room temperature is cooled to, obtains reaction kettle liquid；（3）Reaction kettle liquid is evaporated, solvent is evaporated Fall, remaining solids is dried, and obtains presoma carbon film；（4）Under protective gas atmosphere, the presoma carbon film is existed Reaction temperature reacts 2 ~ 8h under the conditions of being 700 ~ 1000 DEG C, obtains transition metal/carbon composite membrane；（5）By the transition metal/carbon Composite membrane is immersed in the CS of 10ml sulphur₂In solution, after soaking 1 ~ 12h, filter, dry, produce filter membrane material.

2. the preparation method of a kind of filter membrane material according to claim 1, it is characterised in that the transition metal salt is One or more in iron, cobalt, nickel, manganese, copper, the sulfate of zinc, nitrate or villaumite.

3. the preparation method of a kind of filter membrane material according to claim 1, it is characterised in that the solvent is water, second At least one of alcohol, isopropanol.

A kind of 4. preparation method of filter membrane material according to claim 1, it is characterised in that the step（1）In, it is molten The molar concentration of transition metal salt is 0.01 ~ 1mol/L in liquid.

A kind of 5. preparation method of filter membrane material according to claim 1, it is characterised in that the step（2）In, carbon Film is at least one of carbon paper, carbon cloth, carbon fiber, and the addition quality of carbon film is 0.5 ~ 10g.

A kind of 6. preparation method of filter membrane material according to claim 1, it is characterised in that the step（4）In, protect It is Ar, H to protect gas₂、N₂At least one of.

A kind of 7. preparation method of filter membrane material according to claim 1, it is characterised in that the step（4）In, institute It is preferably 750 ~ 900 to state reaction temperature^oC, reaction time are 2 ~ 5h.

A kind of 8. preparation method of filter membrane material according to claim 1, it is characterised in that the step（5）In, institute State the CS of sulphur₂In solution, sulphur and CS₂Mass volume ratio be 1 ~ 50：100 g/mL.

9. as the filter membrane material obtained by claim 1-8 any one.

10. the filter membrane material described in claim 9 removes the application of mercury ion in a liquid.