Amorphous FeS material as well as preparation method and application thereof

Abstract

The invention discloses an amorphous FeS material as well as a preparation method and application thereof, and belongs to the technical field of underground water treatment. A one-step synthesis method is adopted, a ferrous chelating agent, water-soluble polysulfide, sulfide, ferrous salt and other raw materials are mixed under the anaerobic condition, the amorphous FeS material is obtained, the FeS material has high specific surface area, rich surface defects and rapid ion transmission capacity, has efficient reaction activity, and can be used for preparing an amorphous FeS material. Heavy metal ions in wastewater can be quickly reduced and adsorbed, organic matters such as chlorobenzene and the like can be efficiently catalytically degraded, and the catalyst has an excellent application prospect in underground water treatment.

Description

Technical Field

[0001] The present invention belongs to the technical field of groundwater treatment, and in particular relates to an amorphous FeS material and a preparation method and application thereof. Background Art

[0002] Groundwater pollution has become a global environmental issue, with heavy metals and persistent organic pollutants representing significant challenges and key areas of water pollution control. Common remediation technologies include in-situ and ex-situ remediation. Ex-situ remediation is often costly and incomplete, while in-situ remediation offers advantages such as high efficiency, low cost, and minimal disruption to site hydrogeological conditions, making it a hotspot in remediation technology research and development. The selection of in-situ remediation materials is often crucial for groundwater remediation.

[0003] Ferrous sulfide (FeS) is a commonly used in-situ remediation material in groundwater environmental management. It has reducing properties and its surface has abundant active sites (Fe 2+ 、S 2- ), and because of its low preparation cost, it has attracted more and more attention. Heavy metal ions can react with FeS to produce Fe 2+ / Fe 3+ Formation of hydroxide or sulfide precipitates; and Fe 2+ and S 2- Both can act as electron donors, promote the generation of free radicals, and decompose organic matter. However, FeS synthesized naturally and by conventional methods often has good crystallinity, regular lattice, weak electron-donating ability, and generally low reaction activity, resulting in low repair efficiency. Currently, common FeS modification methods include stabilizer coating, physicochemical loading, and stabilizer coating-physicochemical loading, but there are few methods specifically for regulating the crystal form of FeS. The current research on FeS modification is aimed at improving the dispersibility of FeS, rather than specifically regulating the crystal form, and it is difficult to determine whether the improvement in FeS's ability to remove pollutants is due to improved dispersibility or reduced crystallinity. Summary of the Invention

[0004] In response to the above-mentioned prior art, the present invention provides an amorphous FeS material and a preparation method and application thereof, which solves the problems of agglomeration, easy oxidation and deactivation in the process of treating groundwater pollution by FeS materials in the prior art.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is: to provide a method for preparing an amorphous FeS material, comprising the following steps: S1: Dissolve water-soluble sulfide and polysulfide in water to obtain solution 1; S2: dissolving a water-soluble ferrous salt in water to obtain solution 2, adding a ferrous chelating agent solution to solution 2 under an inert gas atmosphere, and stirring to obtain solution 3; S3: adding solution 1 to solution 3 dropwise for reaction, and then collecting the precipitate after the reaction by centrifugation; S4: washing and drying the precipitate to obtain a chelation / polysulfide synergistically modified amorphous FeS material; The beneficial effects of the present invention are as follows: the preparation method provided by the present invention adopts a one-step synthesis method, which is simple and convenient compared to the step-by-step synthesis method. In the preparation process, the preparation method only uses EDA and CaS x , sodium sulfide, ferrous sulfate and other raw materials are directly mixed under anaerobic conditions, with a fast reaction rate, lower economic cost and operability, giving it excellent industrial application prospects.

[0006] On the basis of the above technical solution, the present invention can also be improved as follows.

[0007] Furthermore, the molar ratio of the water-soluble sulfide to the polysulfide is 1:1-10.

[0008] Furthermore, the water-soluble sulfide is potassium sulfide, sodium sulfide, ammonium sulfide, sodium hydrosulfide or potassium hydrosulfide, and the polysulfide is calcium polysulfide, sodium polysulfide or potassium polysulfide.

[0009] Furthermore, the water-soluble ferrous salt is ferrous chloride, ferrous sulfate or ammonium ferrous sulfate.

[0010] Furthermore, the ferrous chelating agent is ethylenediamine, ethylenediaminetetraacetic acid or citric acid.

[0011] Furthermore, the concentration of solution 2 is 0.005-0.007 g / mL.

[0012] Furthermore, the concentration of the ethylenediamine solution was 0.015 g / mL.

[0013] Furthermore, the rate of addition was 1.5-2 mL / min.

[0014] The present invention also provides an amorphous FeS material prepared by the preparation method of the amorphous FeS material.

[0015] The beneficial effects of the present invention are as follows: the surface of the amorphous FeS material provided by the present invention presents a flaky structure, in which nanoparticles are doped to make the structure looser, so that the amorphous FeS material has a high specific surface area, rich surface defects and fast ion transport capability, which significantly improves its chemical reaction activity and electrochemical performance.

[0016] The present invention also provides application of the amorphous FeS material in groundwater treatment.

[0017] The beneficial effects of the present invention are as follows: the amorphous FeS material provided by the present invention has high reaction activity, excellent reduction performance and electron-donating ability, and can efficiently and quickly reduce and adsorb heavy metal ions in wastewater within a wide temperature range, pH range, and dissolved oxygen content range; and the material can quickly and efficiently catalyze the degradation of organic matter such as chlorobenzene, and has excellent application prospects in groundwater treatment. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 1 / 10 of CaS in Example 1 x -EDA-FeS and FeS, EDA-FeS, CaS of Comparative Examples 1 to 3 x -XRD patterns of four FeS materials; Figure 2 XRD patterns of amorphous FeS materials of Examples 1 to 5; Figure 3 The scanning electron microscope images of the amorphous FeS materials of Examples 1 to 5 and the FeS material of Comparative Example 1 are shown; Figure 4 1 / 10 of CaS in Example 1 x -EDA-FeS and FeS, EDA-FeS, CaS of Comparative Examples 1 to 3 x -FeS four materials on the removal of Cr (VI) in groundwater; Figure 5 The figure shows the removal effect of Cr(VI) in groundwater by the amorphous FeS materials of Examples 1 to 5; Figure 6 1 / 10 of CaS in Example 1 x -EDA-FeS and FeS in comparative example 1 show the effects of activated PDS on the degradation of chlorobenzene. DETAILED DESCRIPTION

[0019] The specific implementation methods of the present invention are described in detail below with reference to the embodiments.

[0020] Example 1 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 1.36 g of sodium sulfide nonahydrate and 0.365 mL of 29% calcium polysulfide (provided by Lianyungang Lanxing Industrial Technology Co., Ltd.), mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1. S2: Weigh 0.757 g of EDA and dilute it to 50 mL with deoxygenated deionized water to obtain ethylenediamine solution. Then weigh 1.75 g of ferrous sulfate heptahydrate solid and dissolve it in 300 mL of deoxygenated deionized water to obtain solution 2. Transfer solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add the ethylenediamine solution to solution 2 to obtain solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate. S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 48 h to obtain amorphous FeS material 1 / 10CaS x -EDA-FeS.

[0021] Example 2 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 1.21 g of sodium sulfide nonahydrate and 0.73 mL of 29% calcium polysulfide (provided by Lianyungang Lanxing Industrial Technology Co., Ltd.), mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1; S2: Weigh 0.757 g of EDA and dilute it to 50 mL with deoxygenated deionized water to obtain ethylenediamine solution. Then, weigh 1.5 g of ferrous sulfate heptahydrate solid and dissolve it in 300 mL of deoxygenated deionized water to obtain solution 2. Transfer solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add the ethylenediamine solution to solution 2 to obtain solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.5 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate; S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 36 h to obtain the amorphous FeS material 1 / 5CaS x -EDA-FeS.

[0022] Example 3 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 1.01 g of sodium sulfide nonahydrate and 1.22 mL of 29% calcium polysulfide (provided by Lianyungang Lanxing Industrial Technology Co., Ltd.), mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1. S2: Weigh 0.757 g of EDA and dilute it to 50 mL with deoxygenated deionized water to obtain an ethylenediamine solution. Then, weigh 2.1 g of solid ferrous sulfate heptahydrate and dissolve it in 300 mL of deoxygenated deionized water to obtain Solution 2. Transfer Solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add the ethylenediamine solution to Solution 2 to obtain Solution 3. S3: Add one drop of the solution into solution 3 at a rate of 2 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate; S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 36 h to obtain the amorphous FeS material 1 / 3CaS x -EDA-FeS.

[0023] Example 4 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 0.755 g of sodium sulfide nonahydrate and 1.825 mL of 29% calcium polysulfide (provided by Lianyungang Lanxing Industrial Technology Co., Ltd.), mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1. S2: Weigh 0.757 g of EDA and dilute it to 50 mL with deoxygenated deionized water to obtain ethylenediamine solution. Then weigh 1.75 g of ferrous sulfate heptahydrate solid and dissolve it in 300 mL of deoxygenated deionized water to obtain solution 2. Transfer solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add the ethylenediamine solution to solution 2 to obtain solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate. S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 36 h to obtain the amorphous FeS material 1 / 2CaS x -EDA-FeS.

[0024] Example 5 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 1.36 g of sodium sulfide nonahydrate and 3.65 mL of 29% calcium polysulfide (provided by Lianyungang Lanxing Industrial Technology Co., Ltd.), mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1. S2: Weigh 0.757 g of EDA and dilute it to 50 mL with deoxygenated deionized water to obtain ethylenediamine solution. Then weigh 1.75 g of ferrous sulfate heptahydrate solid and dissolve it in 300 mL of deoxygenated deionized water to obtain solution 2. Transfer solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add the ethylenediamine solution to solution 2 to obtain solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate. S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 36 h to obtain the amorphous FeS material 1 / 1CaS x -EDA-FeS.

[0025] Example 6 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 1.36 g of sodium sulfide nonahydrate and 0.365 mL of 29% sodium polysulfide, mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1. S2: Weigh 4.232 g of EDTA and dilute it to 50 mL with deoxygenated deionized water to obtain EDTA solution. Then, weigh 2.47 g of solid ammonium ferrous sulfate hexahydrate and dissolve it in 300 mL of deoxygenated deionized water to obtain Solution 2. Transfer Solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add the EDTA solution to Solution 2 to obtain Solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate. S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 48 h to obtain the amorphous FeS material Na2S x -EDTA-FeS.

[0026] Example 7 A method for preparing an amorphous FeS material comprises the following steps: S1: Weigh 1.36 g of sodium hydrosulfide and 0.365 mL of 29% potassium polysulfide, mix well, and dilute to 50 mL with deoxygenated deionized water to obtain solution 1. S2: Weigh 2.419 g of citric acid and dilute it to 50 mL with deoxygenated deionized water to obtain a citric acid solution. Then, weigh 1.25 g of ferrous chloride tetrahydrate solid and dissolve it in 300 mL of deoxygenated deionized water to obtain solution 2. Transfer solution 2 to a three-necked flask, turn on the magnetic stirrer, and add the citric acid solution to solution 2 under a nitrogen atmosphere to obtain solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate. S4: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 48 h to obtain the amorphous FeS material K2S x -CA-FeS.

[0027] The amorphous FeS materials prepared in Examples 1 to 5 were prepared with the same raw materials and had a gradient. Subsequent experiments used the amorphous FeS materials prepared in Examples 1 to 5.

[0028] Comparative Example 1 A method for preparing FeS material comprises the following steps: S1: Weigh 1.51 g of sodium sulfide nonahydrate solid and dissolve it in 50 mL of deoxygenated deionized water to obtain solution 1; S2: Weigh 1.75 g of ferrous sulfate heptahydrate solid and dissolve it in 350 mL of deoxygenated deionized water to obtain Solution 2. Transfer Solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add Solution 1 dropwise to Solution 2 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at 5000 r / min for 10 min to collect the precipitate. S3: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 36 h to obtain FeS material.

[0029] Comparative Example 2 A method for preparing an EDA-FeS material comprises the following steps: S1: Weigh 1.51 g of sodium sulfide nonahydrate solid and dissolve it in 50 mL of deoxygenated deionized water to obtain solution 1; S2: Weigh 0.757 g of EDA and dilute it to 50 mL with deoxygenated deionized water to obtain ethylenediamine solution. Then weigh 1.75 g of ferrous sulfate heptahydrate solid and dissolve it in 300 mL of deoxygenated deionized water to obtain solution 2. Transfer solution 2 to a three-necked flask, turn on the magnetic stirrer, and add the ethylenediamine solution to solution 2 under a nitrogen atmosphere to obtain solution 3. S3: Add one drop of the solution into solution 3 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at a rate of 5000 r / min for 10 min to collect the precipitate. S4: The precipitate was washed three times with deoxygenated deionized water, and then dried in a vacuum freeze dryer for 36 h to obtain EDA-FeS material.

[0030] Comparative Example 3 A CaS x -The preparation method of FeS material comprises the following steps: S1: Weigh 3.65 mL of 29% calcium polysulfide and dissolve it in 50 mL of deoxygenated deionized water to obtain solution 1. S2: Weigh 1.75 g of ferrous sulfate heptahydrate solid and dissolve it in 350 mL of deoxygenated deionized water to obtain Solution 2. Transfer Solution 2 to a three-necked flask and turn on the magnetic stirrer. Under a nitrogen atmosphere, add Solution 1 dropwise to Solution 2 at a rate of 1.67 mL / min to react. After the reaction, centrifuge the mixed solution at 5000 r / min for 10 min to collect the precipitate. S3: The precipitate was washed three times with deoxygenated deionized water and then dried in a vacuum freeze dryer for 36 h to obtain CaS x -FeS material.

[0031] Experimental Example 1 1 / 10 CaS of Example 1 x -EDA-FeS and FeS, EDA-FeS, CaS of Comparative Examples 1 to 3 x -FeS material was subjected to XRD analysis, and the results are as follows Figure 1 As shown in the figure, it can be found that the crystallinity of unmodified FeS is the highest; the crystallinity of EDA-FeS is greatly reduced compared with that of unmodified FeS, but it still has a certain degree of crystallinity; CaS x -FeS has no diffraction peak corresponding to FeS, so it is amorphous FeS, but has a diffraction peak corresponding to S, and the diffraction peak intensity is relatively high; 1 / 10CaS x -EDA-FeS has only one weak diffraction peak representing Fe2O3, which is also amorphous FeS.

[0032] Experimental Example 2 The amorphous FeS materials of Examples 1 to 5 were subjected to XRD analysis, and the results were as follows: Figure 2As shown, the diffraction peaks of FeS completely disappear in the amorphous FeS materials at all polysulfide ratios, replaced by diffraction peaks representing Fe2O3 (JCPSD: 39-1346) and S (JCPDS: 08-0247). The diffraction peaks of the amorphous FeS materials at ratios of 1 / 10, 1 / 5, and 1 / 3 completely correspond to those of the Fe2O3 standard card, while the amorphous FeS materials at ratios of 1 / 2 and 1 / 1 exhibit diffraction peaks corresponding to S in addition to Fe2O3. This result indicates that the amorphous FeS materials modified with both EDA and polysulfides are amorphous FeS, but the S content in the amorphous FeS materials increases with increasing polysulfide ratios.

[0033] Experimental Example 3 The amorphous FeS materials of Examples 1 to 5 and the FeS material of Comparative Example 1 were analyzed by scanning electron microscopy. Figure 3 , the figure illustrates that there are significant differences in the morphological characteristics of the amorphous FeS material prepared by chelation and polysulfide modification and the unmodified FeS. The unmodified FeS has a dense shell and a fish-scale-shaped layered stacking on the surface; while the amorphous FeS materials of Examples 1 to 5 have a flaky structure on the surface, in which the doping of nanoparticles makes this structure more loose, which also increases the specific surface area of ​​the FeS material and increases the adsorption sites on the surface of the material. When the polysulfide ratio increases to 1 / 5, the flaky structure becomes more and begins to wrap some of the nanoparticles. When the polysulfide ratio reaches 1 / 3, a flower-like structure begins to appear. When the polysulfide ratio reaches 1 / 1, all the nanoparticles are replaced by a flower-like structure.

[0034] Experimental Example 4 Weigh 0.02 g of FeS, EDA-FeS, and CaS from Comparative Examples 1 to 3 respectively. x -FeS material and 1 / 10CaS of Example 1 x The -EDA-FeS material was placed in a 50 mL plastic centrifuge tube, and 40 mL of a 50 mg / L Cr(VI) solution was added. A blank control group without Cr(VI) was also set up, with replicates for each experimental group. The centrifuge tube was placed in a rotary shaker for reaction at room temperature. After 5, 15, 30, 60, 120, and 240 minutes, the shaker was stopped and 0.5 mL of the solution was pipetted into a 10 mL centrifuge tube and the volume was adjusted to 5 mL. The supernatant was filtered through a 0.22 μm filter membrane, and 0.5 mL of the filtered solution was again pipetted into a 10 mL centrifuge tube and the volume was adjusted to 5 mL. The Cr(VI) content in the solution was then measured.

[0035] Test results such as Figure 4 , EDA-FeS, CaS2-FeS and 1 / 10CaS x-EDA-FeS had much higher removal efficiency on Cr(VI) than unmodified FeS (2.59%), among which EDA-FeS (82.2%) and CaS x -FeS (81.9%) had a similar removal effect on Cr(VI), while 1 / 10CaS x -EDA-FeS (93.7%) has a higher removal rate of Cr(VI) than EDA-FeS and CaS x -FeS.

[0036] Experimental Example 5 Weigh 0.02 g of the amorphous FeS materials of Examples 1 to 5 respectively, and use the same method as in Experimental Example 4 to test. The test results are as follows: Figure 5 As shown, 1 / 10 CaS was added x -EDA-FeS has the best removal effect on Cr(VI), with a removal rate of 93.7%. As the proportion of polysulfides increases, the removal rate of Cr(VI) by amorphous FeS material decreases, and 1 / 5CaS x -EDA-FeS, 1 / 3 CaS x -EDA-FeS and 1 / 2 CaS x -EDA-FeS for Cr(VI) removal rates were 82.3%, 82.3% and 80.9% respectively.

[0037] Experimental Example 6 In a 30 mL brown screw-capped glass bottle, 0.2 g of 1 / 10 CaS prepared in Example 1 was added. x -EDA-FeS and the FeS from Comparative Example 1 were then added with 29.5 mL of a 69.0879 mg / L chlorobenzene solution using a glass syringe. The solution was sealed with a cap. 0.5 mL of a 6 mmol / L PDS solution was added using a microinjection syringe. The reaction timer was started, and the final volume of the solution was 30 mL. The initial chlorobenzene concentration was 67.9364 mg / L. At regular intervals, 1 mL of the reaction solution was withdrawn from the corresponding glass bottle and added to a brown screw-capped glass bottle containing 3 mL of the extract and 1 mL of the quencher to terminate the reaction. The MCB concentration of the reaction solution was measured. The experimental environment temperature was 25°C, and the pH of the chlorobenzene solution was 7.0.

[0038] The experimental results are as follows Figure 6 The degradation rate of MCB by FeS / PDS system is relatively stable from 0 to 120 min. The image shows that the concentration change is almost a straight line. At 120 min, the MCB removal rate is not high at 29.94%. xThe -EDA-FeS / PDS system can degrade MCB faster and better within 0-120 min. Therefore, the amorphous FeS material modified by the present invention can efficiently degrade organic matter.

[0039] Although the specific embodiments of the present invention have been described in detail in conjunction with the embodiments, this should not be construed as limiting the scope of protection of this patent. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

Claims

1. A method for preparing an amorphous FeS material, characterized in that: The following steps are involved: S1: Dissolve water-soluble sulfide and polysulfide in water to obtain solution 1; S2: dissolving a water-soluble ferrous salt in water to obtain solution 2, adding a ferrous chelating agent solution to solution 2 under an inert gas atmosphere, and stirring to obtain solution 3; S3: adding solution 1 to solution 3 dropwise for reaction, and then collecting the precipitate after the reaction by centrifugation; S4: The precipitate is washed and dried to obtain a chelation / polysulfide synergistically modified amorphous FeS material.

2. The method for preparing the amorphous FeS material according to claim 1, wherein: The molar ratio of the water-soluble sulfide to the polysulfide is 1:1-10.

3. The method for preparing the amorphous FeS material according to claim 1, wherein: The water-soluble sulfide is potassium sulfide, sodium sulfide, ammonium sulfide, sodium hydrosulfide or potassium hydrosulfide, and the polysulfide is calcium polysulfide, sodium polysulfide or potassium polysulfide.

4. The method for preparing the chelation / polysulfide synergistically modified amorphous FeS material according to claim 1, characterized in that: The water-soluble ferrous salt is ferrous chloride, ferrous sulfate or ammonium ferrous sulfate.

5. The method for preparing the chelation / polysulfide synergistically modified amorphous FeS material according to claim 1, characterized in that: The ferrous chelating agent is ethylenediamine, ethylenediaminetetraacetic acid or citric acid.

6. The method for preparing the amorphous FeS material according to claim 1, wherein: The concentration of the second solution is 0.005-0.007 g / mL.

7. The method for preparing the amorphous FeS material according to claim 1, wherein: The concentration of the ethylenediamine solution is 0.015 g / mL.

8. The method for preparing the amorphous FeS material according to claim 1, wherein: The dropwise addition rate is 1.5-2 mL / min.

9. The amorphous FeS material obtained by the preparation method according to any one of claims 1 to 8.

10. Use of the amorphous FeS material according to claim 9 in groundwater treatment.

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