CN111960522A - Anti-oxidation micron vulcanized zero-valent iron material and preparation method thereof - Google Patents

Anti-oxidation micron vulcanized zero-valent iron material and preparation method thereof Download PDF

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CN111960522A
CN111960522A CN202010856387.6A CN202010856387A CN111960522A CN 111960522 A CN111960522 A CN 111960522A CN 202010856387 A CN202010856387 A CN 202010856387A CN 111960522 A CN111960522 A CN 111960522A
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zero
valent iron
tea stem
solution
micron
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陈胜文
李盟
王彦云
王利军
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Shanghai Polytechnic University
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    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00—Treatment of water, waste water, or sewage
    • C02F1/70—Treatment of water, waste water, or sewage by reduction
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/10—Inorganic compounds
    • C02F2101/20—Heavy metals or heavy metal compounds
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C02F2101/306—Pesticides
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C02F2101/308—Dyes; Colorants; Fluorescent agents
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C02F2101/36—Organic compounds containing halogen
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2101/00—Nature of the contaminant
    • C02F2101/30—Organic compounds
    • C02F2101/38—Organic compounds containing nitrogen
    • C—CHEMISTRY; METALLURGY
    • C02—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F—TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F2103/00—Nature of the water, waste water, sewage or sludge to be treated
    • C02F2103/06—Contaminated groundwater or leachate

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  • Life Sciences & Earth Sciences (AREA)
  • Hydrology & Water Resources (AREA)
  • Engineering & Computer Science (AREA)
  • Environmental & Geological Engineering (AREA)
  • Water Supply & Treatment (AREA)
  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Treatment Of Water By Oxidation Or Reduction (AREA)
  • Compounds Of Iron (AREA)
  • Processing Of Solid Wastes (AREA)

Abstract

The invention discloses an antioxidant micron sulfurized zero-valent iron material and a preparation method thereof. The preparation method comprises the following steps: under the air atmosphere, adding a mixed solution containing a tea stem extracting solution and a sulfur-containing compound into a ferrous salt solution, mixing, performing room-temperature liquid-phase reduction reaction, and after the reaction is finished, performing solid-liquid separation to obtain a solid, namely the antioxidant micron zero-valent iron sulfide material; wherein: the tea stem extracting solution is a filtrate obtained by placing crushed tea stems in water, stirring for a period of time at the temperature of 60-80 ℃, and filtering; the sulfur-containing compound is sodium sulfide, sodium thiosulfate or sodium dithionite. The method has the advantages of mild reaction conditions, simple operation, good process repeatability, low manufacturing cost, environmental protection and suitability for large-scale production, and the prepared vulcanized zero-valent iron has good dispersibility and oxidation resistance and has wide application prospect in the field of treating large-scale wastewater, underground water or soil pollution.

Description

Anti-oxidation micron vulcanized zero-valent iron material and preparation method thereof
Technical Field
The invention relates to the technical field of micro-nano materials, in particular to an anti-oxidation micro-vulcanized zero-valent iron material and a preparation method thereof.
Background
In recent years, the development of micro-nano technology brings a potential new method for pollution remediation technology. The nanometer-sized zero-valent iron (nZVI) has the advantages of being far superior to the traditional environmental materials, such as large specific surface area, high reaction activity and strong reduction capability, and can effectively remove various pollutants such as refractory organic matters (including pesticides, insecticides, polychlorinated biphenyl, phenol organic matters and the like), heavy metals, nitrates and the like in water. The nano zero-valent iron is magnetic and easy to separate from a water body, so that the nano zero-valent iron is widely concerned, but has certain problems in actual pollutant remediation, such as easy oxidation, easy agglomeration and the like. The micron-sized zero-valent iron (mZVI) overcomes certain problems of the nanometer scale, and is relatively widely applied to actual pollutant remediation.
At present, zero-valent iron is used for wastewater treatment and soil and underground water remediation, and various data show that the zero-valent iron has a good removal effect on heavy metals, organic halides, nitrates and the like in a water body, but the preparation conditions and cost of the zero-valent iron and the pollution of sodium borohydride/potassium borohydride serving as a reducing agent limit the development of the zero-valent iron.
Chinese patent CN110980858A discloses a biochar-loaded nano zero-valent iron sulfide material which is high in reaction activity and strong in oxidation resistance, but the material needs to be prepared under the protection of inert gas, needs to be pyrolyzed, has high requirements on equipment, and is polluted by sodium borohydride serving as a reducing agent. Chinese patent CN109607635A discloses a method for preparing sulfurized zero-valent iron by using sulfur powder and zero-valent iron, which has low energy consumption and short preparation time, but the preparation environment needs nitrogen protection, and the preparation process has high requirements on the pH of the aqueous solution and inorganic salts.
Therefore, it is necessary to explore a new method for preparing zero-valent iron sulfide to solve the above problems.
Disclosure of Invention
In view of the defects of the prior art, the invention aims to provide an antioxidant micron sulfurized zero-valent iron material and a preparation method thereof. The method prepares the micron zero-valent iron sulfide material by a liquid phase reduction method in the air atmosphere, does not need the protection of inert gas, is simple to operate, green and environment-friendly, has mild reaction conditions, and further reduces the cost; the micron vulcanized zero-valent iron material prepared by the method has good dispersibility and strong oxidation resistance, and can be used for removing heavy metals in water. The technical scheme of the invention is specifically introduced as follows.
A preparation method of an oxidation-resistant micron sulfurized zero-valent iron material comprises the following steps:
mixing a mixed solution containing a tea stem extracting solution and a sulfur-containing compound with a ferrous salt solution in an air atmosphere to perform room-temperature liquid-phase reduction reaction, and after the reaction is finished, performing solid-liquid separation to obtain a solid, namely the antioxidant micron zero-valent iron sulfide material; wherein: the tea stem extracting solution is a filtrate obtained by placing crushed tea stems in water, stirring for a period of time at the temperature of 60-80 ℃, and filtering; the sulfur-containing compound is sodium sulfide Na2S, sodium thiosulfate Na2S2O3Or sodium dithionite Na2S2O4。
In the invention, the ferrous salt is ferrous sulfate or ferrous chloride.
In the invention, the tea stem is one or more of green tea stem, black tea stem or white tea stem.
In the invention, when the tea stem extracting solution is prepared, the feeding ratio of the tea stem to water is 5-50 g/L, and the stirring time is 0.5-12 h; the concentration of the ferrite solution is 0.01-0.1 mol/L; the molar ratio of the ferrous salt to the sulfur-containing compound is 1: 0.01-1: 0.5; the volume ratio of the mixed solution containing the tea stem extracting solution and the sulfur-containing compound to the ferrous salt solution is 1: 1-10: 1.
The invention further provides an anti-oxidation micron vulcanized zero-valent iron material prepared by the preparation method.
Compared with the prior art, the invention has the beneficial effects that:
the tea stem extracting solution contains a reducing component, and plays a reducing role in the material preparation process.
The method has the advantages of wide raw material source, low price, simple operation, environmental protection, no need of inert gas protection, mild reaction conditions, good process repeatability and contribution to large-scale popularization, and the prepared zero-valent iron sulfide has high oxidation resistance, good dispersibility and remarkable economic, environmental and social effects.
The micron zero-valent iron sulfide material prepared by the invention can be applied to treating heavy metal, pesticide, azo dye, halogenated organic matter and nitro organic matter pollution in wastewater, underground water or soil, and has high treatment efficiency and high treatment speed.
Drawings
FIG. 1 is an SEM photograph of a zero-valent iron sulfide prepared in example 1 of the present invention; a) 25000 times magnification, b) 5000 times magnification.
FIG. 2 is an EDS diagram of zero-valent iron sulfide prepared in example 1 of the present invention.
FIG. 3 is an XRD pattern of the zero-valent iron sulfide prepared in example 1 of the present invention.
FIG. 4 is a particle size distribution diagram of zero-valent iron sulfide prepared in example 1 of the present invention.
FIG. 5 is an oxidation resistance diagram of the zero-valent iron sulfide prepared in example 1 of the present invention.
FIG. 6 is a diagram showing the effect of removing Cr (VI) from the zero-valent iron sulfide obtained in example 1 of the present invention.
FIG. 7 is a diagram showing the effect of removing Cr (VI) from the zero-valent iron sulfide prepared in example 2 of the present invention.
FIG. 8 is a diagram showing the effect of removing Cr (VI) from the zero-valent iron sulfide obtained in example 3 of the present invention.
FIG. 9 is a graph showing the effect of removing 4-nitrophenol from the zero-valent iron sulfide prepared in example 3 of the present invention.
Detailed Description
The invention provides a method for preparing an antioxidant, green and environment-friendly micron vulcanized zero-valent iron material in an air atmosphere and application thereof. The invention will be further explained with reference to the following figures and specific embodiments.
Example 1
Crushing 3 g of green tea stalks, adding the crushed green tea stalks into 400 mL of deionized water, stirring the mixture at the temperature of 80 ℃ for 2 hours, and filtering the mixture; measuring 150 mL of filtrate, and adding 0.386 g of sodium sulfide nonahydrate into the filtrate to obtain a mixed solution; weighing 2.78 g of ferrous sulfate heptahydrate, and dissolving the ferrous sulfate heptahydrate into 100 mL of deionized water to obtain a ferrous solution; adding the mixed solution into the ferrous solution and stirring; and (3) carrying out solid-liquid separation after reacting for 30 min, and drying the solid in a vacuum drying oven to obtain the micron-sized zero-valent iron sulfide.
Observing the micro-morphology of the prepared sample by using SEM and EDS, wherein the results are shown in figures 1 and 2, and the zero-valent iron sulfide is wrapped by organic matters, the spheres are irregular, and meanwhile, the particles are adhered into blocks to form a micron-sized structure; EDS analysis of the Fe-S alloy detects Fe and S elements, and indicates that Fe exists0And FeS formation, the C and O elements indicating the presence of organics or iron oxides. The X-ray diffraction of the sample showed that there was a distinct organic peak and an insignificant iron peak, probably because the zero-valent iron sulfide was encapsulated by the organic or was present in an amorphous form, as shown in fig. 3. Particle size analysis of the material was performed using malvern 2000, and it can be seen from fig. 4 that the center particle size of the zero-valent iron sulfide was around 8 μm, indicating that the nanoparticles agglomerated to form a microstructure of the material, which is consistent with the SEM image results. The data show that the particle size of the particles is mainly distributed in the range of 2.755-20.814 mu m. 10 mL of the material is put into a measuring cylinder and is shot at regular time, as can be seen from figure 5, the micron-sized zero-valent iron sulfide still has certain anti-settling property after being placed for 7 days, and meanwhile, the material still has no aging sign after being placed for 7 days in an open mode, which indicates that the material has strong oxidation resistance. The material of the measuring cylinder can be rapidly and uniformly dispersed by shaking, which shows that the material has good dispersibility.
0.05g of zero valent iron sulfide was weighed into 50 mL of 20 mg/LCr (VI) solution and the removal effect is shown in FIG. 6. In the embodiment, the removal efficiency of 0.05g of zero-valent iron sulfide added in 20 min to 50 mL of 20 mg/L Cr (VI) solution is 99%, and the removal effect is obvious.
Example 2
Crushing 5g of black tea stalks, adding the crushed black tea stalks into 500 mL of deionized water, stirring the mixture for 1 hour at 80 ℃, and filtering the mixture; measuring 200 mL of filtrate, and adding 0.4 g of sodium thiosulfate into the filtrate to obtain a mixed solution; weighing 3.0 g of ferrous chloride and dissolving into 100 mL of deionized water to obtain a ferrous solution; adding the mixed solution into the ferrous solution and stirring; and (3) carrying out solid-liquid separation after reacting for 30 min, and drying the solid in a vacuum drying oven to obtain the micron-sized zero-valent iron sulfide.
By adopting the same experimental conditions as example 4 in Chinese patent 109607635A, 0.2 g of zero-valent iron sulfide is weighed and added into 200 mL of Cr (VI) solution with the concentration of 10ppm, and the removal effect is shown in figure 7. In the embodiment, the removal efficiency of the zero-valent iron sulfide to the Cr (VI) solution within 1h is 76.3%, 2h reaches 85%, and compared with the removal rate of the Cr (VI) solution within 8h in embodiment 4 in Chinese patent 109607635A, the removal rate reaches 86%, and the removal effect is remarkable.
Example 3
Crushing 8 g of green tea stalks, adding the crushed stalks into 500 mL of deionized water, stirring the mixture at the temperature of 80 ℃ for 1.5h, and filtering the mixture; measuring 200 mL of filtrate, and adding 0.400 g of sodium sulfide nonahydrate into the filtrate to obtain a mixed solution; weighing 2.78 g of ferrous sulfate heptahydrate, and dissolving the ferrous sulfate heptahydrate into 100 mL of deionized water to obtain a ferrous solution; adding the mixed solution into the ferrous solution and stirring; and (3) carrying out solid-liquid separation after reacting for 30 min, and drying the solid in a vacuum drying oven to obtain the micron-sized zero-valent iron sulfide.
0.1 g of zero-valent iron sulfide was weighed and added to 50 mL of 50 mg/L Cr (VI) solution, and the removal effect is shown in FIG. 8. In the embodiment, the removal efficiency of 0.1 g of zero-valent iron sulfide to 50 mL of 50 mg/L Cr (VI) solution in 20 min is about 85%, the removal efficiency can reach 99% in 60 min, and the removal effect is obvious.
Example 4
Crushing 8 g of white tea stalks, adding the crushed white tea stalks into 500 mL of deionized water, stirring the mixture at 80 ℃ for 1.5h, and filtering the mixture; measuring 200 mL of filtrate, and adding 0.400 g of sodium sulfide nonahydrate into the filtrate to obtain a mixed solution; weighing 2.78 g of ferrous sulfate heptahydrate, and dissolving the ferrous sulfate heptahydrate into 100 mL of deionized water to obtain a ferrous solution; adding the mixed solution into the ferrous solution and stirring; and (3) carrying out solid-liquid separation after reacting for 30 min, and drying the solid in a vacuum drying oven to obtain the micron-sized zero-valent iron sulfide.
0.05g of zero-valent iron sulfide was weighed into 50 mL of a 100 mg/L4-nitrophenol solution, and the removal effect was as shown in FIG. 8. In the embodiment, the removal efficiency of 0.05g of zero-valent iron sulfide to 100 mg/L of 4-nitrophenol solution in 20 min is 99%, and the removal effect is obvious.

Claims (5)

1. The preparation method of the antioxidant micron sulfurized zero-valent iron material is characterized by comprising the following steps:
mixing a mixed solution containing a tea stem extracting solution and a sulfur-containing compound with a ferrous salt solution in an air atmosphere to perform room-temperature liquid-phase reduction reaction, and after the reaction is finished, performing solid-liquid separation to obtain a solid, namely the antioxidant micron zero-valent iron sulfide material; wherein: the tea stem extracting solution is a filtrate obtained by placing crushed tea stems in water, stirring for a period of time at the temperature of 60-80 ℃, and filtering; the sulfur-containing compound is sodium sulfide Na2S, sodium thiosulfate Na2S2O3Or sodium dithionite Na2S2O4。
2. The method according to claim 1, wherein the ferrous salt is ferrous sulfate or ferrous chloride.
3. The method according to claim 1, wherein the tea stem is one or more of a green tea stem, a black tea stem or a white tea stem.
4. The preparation method according to claim 1, wherein when the tea stem extracting solution is prepared, the feeding ratio of the tea stem to water is 5 g/L-50 g/L, and the stirring time is 0.5 h-12 h; the concentration of the ferrite solution is 0.01-0.1 mol/L;
the molar ratio of the ferrous salt to the sulfur-containing compound is 1: 0.01-1: 0.5; the volume ratio of the mixed solution containing the tea stem extracting solution and the sulfur-containing compound to the ferrous salt solution is 1: 1-10: 1.
5. An oxidation-resistant micro-sized zero-valent iron sulfide material prepared by the preparation method according to any one of claims 1 to 4.
CN202010856387.6A 2020-08-24 2020-08-24 Anti-oxidation micron vulcanized zero-valent iron material and preparation method thereof Pending CN111960522A (en)

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Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060083924A1 (en) * 2003-05-29 2006-04-20 Crc For Waste Management And Pollution Control Limited Process for producing a nanoscale zero-valent metal
US20100200501A1 (en) * 2008-05-16 2010-08-12 Verutek Technologies ,Inc. Green synthesis of nanometals using plant extracts and use thereof
CN105945299A (en) * 2016-04-28 2016-09-21 杭州电子科技大学 Application of nano-iron synthesized by tea leaves in p,p'-DDT removal
CN108636360A (en) * 2018-05-22 2018-10-12 福建师范大学 A kind of preparation method and application of functionalized nano iron sulfide

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060083924A1 (en) * 2003-05-29 2006-04-20 Crc For Waste Management And Pollution Control Limited Process for producing a nanoscale zero-valent metal
US20100200501A1 (en) * 2008-05-16 2010-08-12 Verutek Technologies ,Inc. Green synthesis of nanometals using plant extracts and use thereof
CN105945299A (en) * 2016-04-28 2016-09-21 杭州电子科技大学 Application of nano-iron synthesized by tea leaves in p,p'-DDT removal
CN108636360A (en) * 2018-05-22 2018-10-12 福建师范大学 A kind of preparation method and application of functionalized nano iron sulfide

Non-Patent Citations (1)

* Cited by examiner, † Cited by third party
Title
梁莉等: "硫化纳米零价铁（S-nZVI）对水体中镉的去除研究", 《环境科学学报》 *

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Application publication date: 20201120