阅读说明：本技术 一种零价铁材料Fe@铁氟化物及其制备方法 (Zero-valent iron material Fe @ iron fluoride and preparation method thereof ) 是由 彭星 张亚丽 于 2019-08-09 设计创作，主要内容包括：本发明涉及一种零价铁材料Fe@铁氟化物及其制备方法。本发明提供一种零价铁材料Fe@铁氟化物,零价铁材料的表面层为铁氟化物层,铁氟化物层取代了零价铁壳层的铁氧化物。制备方法：将氢氟酸溶液和零价铁加热反应一段时间,后处理得到零价铁材料Fe@铁氟化物。本发明提供的零价铁材料Fe@铁氟化物具有极高活性,能极大地促进零价铁的腐蚀效率,提升去除重金属效率和零价铁的利用率,并有利于节约零价铁技术的成本。(The invention relates to a zero-valent iron material Fe @ iron fluoride and a preparation method thereof. The invention provides a zero-valent iron material Fe @ iron fluoride, wherein the surface layer of the zero-valent iron material is an iron fluoride layer, and the iron fluoride layer replaces iron oxide of a zero-valent iron shell layer. The preparation method comprises the following steps: and heating and reacting the hydrofluoric acid solution with zero-valent iron for a period of time, and performing post-treatment to obtain the zero-valent iron material Fe @ iron fluoride. The zero-valent iron material Fe @ iron fluoride provided by the invention has extremely high activity, can greatly promote the corrosion efficiency of zero-valent iron, improves the heavy metal removal efficiency and the utilization rate of the zero-valent iron, and is beneficial to saving the cost of the zero-valent iron technology.)

1. A zero-valent iron material Fe @ iron fluoride is characterized in that: the surface layer of the zero-valent iron material is an iron fluoride layer, and the iron fluoride layer replaces the iron oxide of the zero-valent iron shell layer.

2. The zero-valent iron material Fe @ iron fluoride of claim 1, wherein: the iron fluoride includes but is not limited to Fe₃F₈·2H₂O and Fe₂F₅·2H₂O。

3. A method of preparing the zero-valent iron material Fe @ iron fluoride of claim 1, wherein: the method comprises the following steps: and heating and reacting the hydrofluoric acid solution with zero-valent iron for a period of time, and performing post-treatment to obtain the zero-valent iron material Fe @ iron fluoride.

4. The method of claim 3, wherein: the post-treatment comprises the following steps: after solid-liquid separation, washing with deionized water and ethanol respectively, and finally drying in a vacuum drying oven.

5. The method of claim 3, wherein: the zero-valent iron is micron-sized zero-valent iron; the hydrofluoric acid is from hydrofluoric acid wastewater discharged by industries such as market or photovoltaic industry.

6. The method according to claim 3, wherein the hydrofluoric acid concentration is 0.1-2M and the amount of zero-valent iron is 80-400 g/L.

7. The process according to claim 3, wherein the reaction temperature is 50 to 120 ℃ and the reaction time is 2 to 7 hours.

8. A method of removing heavy metal contamination using the zero-valent iron material Fe @ iron fluoride of claim 1.

9. The method of claim 8, wherein: the dosage of the zero-valent iron material Fe @ iron fluoride is 0.2-1 g/L.

10. The method of claim 8, wherein: said heavy metal contamination comprises chromium and arsenic; the heavy metal pollution concentration is 1-10 mg/L; stirring is carried out in the removing process.

Technical Field

The invention belongs to the field of pollutant remediation in water and preparation of environmental materials, and particularly relates to a novel zero-valent iron material Fe @ iron fluoride, a preparation method and application thereof in pollutant removal.

Background

The zero-valent iron is used as a green, environment-friendly, economic and efficient multifunctional environment-friendly material and has good research and application prospects. Through research and development for more than 20 years, zero-valent iron has a good effect in the aspects of treating heavy metals, organic matters, nitrogen, phosphorus, mixed pollutants and the like, but the large-area application of the zero-valent iron in actual environmental remediation still has a challenge, mainly because iron is easy to react with oxygen or water, an iron oxide shell layer is formed on the surface of the zero-valent iron, and the iron oxide shell layer plays a role in protecting the zero-valent iron from being further oxidized and simultaneously can prevent the zero-valent iron from being corroded, namely the capacities of the iron to give electrons and release divalent iron ions are influenced. In order to solve this problem, researchers of the zero-valent iron technology have proposed various modification technologies, such as synthesis of nano zero-valent iron by changing the particle size of zero-valent iron, preparation of bimetallic materials such as iron copper or iron nickel, pretreatment of hydrogen and hydrochloric acid, reinforcement of weak magnetic field and microwave and electric field, and reinforcement technology of adding inorganic ions. Although the above improved technology can effectively improve the pollutant removal capability of zero-valent iron, researchers find that a new iron oxide shell layer is formed on the surface of zero-valent iron as the reaction proceeds, so that the utilization efficiency of zero-valent iron is affected, and therefore how to further improve the utilization efficiency of zero-valent iron is an urgent problem to be solved for influencing the comprehensive popularization and application of the zero-valent iron technology.

Disclosure of Invention

The invention aims to provide a novel zero-valent iron material Fe @ iron fluoride and a preparation method thereof.

In order to achieve the purpose, the technical scheme adopted by the invention is as follows:

the zero-valent iron material Fe @ iron fluoride is provided, the surface layer of the zero-valent iron material is an iron fluoride layer, and the iron fluoride layer replaces the iron oxide of the zero-valent iron shell layer.

In the above scheme, the iron fluoride includes but is not limited to Fe₃F₈·2H₂O and Fe₂F₅·2H₂O。

The preparation method of the zero-valent iron material Fe @ iron fluoride is provided, wherein hydrofluoric acid solution and zero-valent iron are heated and reacted for a period of time, and the zero-valent iron material Fe @ iron fluoride is obtained through post-treatment.

According to the scheme, the post-treatment comprises the following steps: after solid-liquid separation, washing with deionized water and ethanol respectively, and finally drying in a vacuum drying oven. The solid-liquid separation process can adopt the technologies of magnetic separation, gravity separation, centrifugal separation and the like.

According to the scheme, the mixture is washed for 3 times by deionized water and ethanol respectively, and dried for 12-18h in a vacuum drying oven at 25 ℃.

According to the scheme, the hydrofluoric acid is sourced from hydrofluoric acid wastewater discharged by industries such as market or photovoltaics.

According to the scheme, the concentration of the hydrofluoric acid is 0.1-2M, and the dosage of the zero-valent iron is 80-400 g/L.

According to the scheme, the reaction temperature is 50-120 ℃, and the reaction time is 2-7 h.

According to the scheme, the zero-valent iron is micron-sized zero-valent iron.

Provides a method for removing heavy metal pollution by using the zero-valent iron material Fe @ iron fluoride.

According to the scheme, the addition amount of the zero-valent iron material Fe @ iron fluoride is 0.2-1 g/L.

According to the scheme, the heavy metal pollution comprises chromium and arsenic.

According to the scheme, the heavy metal pollution concentration is 1-10 mg/L.

According to the scheme, stirring is carried out in the removing process, and the rotating speed can be 200 r/min.

The invention has the beneficial effects that:

the invention takes zero-valent iron (such as factory scrap iron, commercial zero-valent iron powder and the like) as a raw material, adds hydrofluoric acid for heating and modification, destroys the original iron oxide shell layer of the zero-valent iron by utilizing the acidity of hydrofluoric acid, and further forms a new iron fluoride layer on the surface of the zero-valent iron, so that the hydrophilicity of the prepared Fe @ iron fluoride is greatly improved, the Fe @ iron fluoride has extremely high activity, the corrosion efficiency of the zero-valent iron is greatly promoted, the efficiency of removing heavy metal and the utilization rate of the zero-valent iron are improved, and the cost of the zero-valent iron technology is saved.

Drawings

FIG. 1 is an XRD results plot of the original zero-valent iron (B) and Fe @ iron fluoride (Fe @ iron fluoride) (A) (example 1) (. t.Fe)₃F₈·2H₂O(PDF 76-2285)◆Fe₂F₅·2H₂O(PDF 84-0880)▲Fe⁰)；

FIG. 2 shows the original zero-valent iron (A) and Fe @ iron fluoride (Fe @ FeF)_x) Graph of contact angle results of (B) (example 1);

FIG. 3 shows Fe @ iron fluoride (Fe @ FeF)_x) Removal of chromium heavy metalsFruit (example 1);

FIG. 4 shows Fe @ Fe fluoride (Fe @ FeF)_x) Removal of heavy metal arsenic (example 1).

Detailed Description