Normal-temperature bionic reductive dehalogenation suspension system as well as preparation method and application thereof

Abstract

The invention discloses a normal-temperature bionic reductive dehalogenation suspension system and a preparation method and application thereof.The normal-temperature bionic reductive dehalogenation suspension system is formed by mixing nitrogen-rich biochar, patina and cobalt hydroxide according to the mass ratio of 1: (1-5): (0.8-3.8) in a water phase at the normal temperature, nitrogen functional groups in the nitrogen-rich biochar and cobalt hydroxide are utilized to synergistically construct a cobalamin-like structure, active hydrogen is generated and stabilized in situ, and the suspension system is obtained. The patina provides reducing iron species, participates in electron transfer, can form heterojunctions with cobalt hydroxide, and can also be directly adsorbed in a nitrogen structure of bone black, so that the reaction is efficiently carried out, the patina has enzyme-like catalysis characteristics, efficient reduction and dehalogenation of halogenated organic pollutants such as trichloroethylene are realized, the reaction conditions are mild, and the method is suitable for industrial production. Meanwhile, acetylene can be directionally converted into ethylene and ethane.

Description

Technical Field

[0001] This invention relates to the field of environmental remediation technology, specifically to a room-temperature biomimetic reductive dehalogenation suspension system, its preparation method, and its application. Background Technology

[0002] Halogenated organic pollutants (such as trichloroethylene and carbon tetrachloride) are frequently detected in groundwater and soil at contaminated sites worldwide. Their high toxicity, persistent degradation, and environmental persistence have made them a significant source of soil and groundwater pollution. These pollutants generally pose potential carcinogenic, teratogenic, and mutagenic risks. Due to the low water solubility and high migration capacity of chlorinated solvents, their pollution range can easily expand, and once they enter groundwater, they are difficult to remove, thus threatening water quality and even human health, making remediation and treatment extremely challenging. Currently, commonly used remediation technologies for halogenated organic pollutants include biological dehalogenation, chemical reduction dehalogenation, and advanced oxidation.

[0003] Chemical reduction dehalogenation has attracted widespread attention due to its rapid reaction rate and wide applicability. Chemical reduction dehalogenation refers to the chemical process of replacing halogen atoms (Cl, Br, I, etc.) in organic compound molecules with hydrogen atoms or other groups through a reduction reaction, ultimately removing the halogen atoms. However, existing chemical reduction dehalogenation systems generally suffer from the following problems: Firstly, the acquisition of cobalt-based or iron-based functional materials typically relies on cumbersome steps such as high-temperature calcination, heterogeneous doping, and carrier fixation, which not only consumes a lot of energy and requires demanding equipment but also leads to large batch variations and hinders large-scale scaling. Secondly, limited by short electron transport paths and insufficient exposure of active sites, pollutant reduction is often incomplete, easily stalling and accompanied by the generation of more toxic byproducts such as chloroform, thus increasing secondary environmental risks. Furthermore, existing systems mostly remain at the purely chemical level with a simple combination of "zero-valent metal + electron-donating agent," making it difficult to achieve breakthroughs in catalytic efficiency and selectivity, failing to meet the needs of rapid, safe, and green remediation in complex sites. Summary of the Invention

[0004] The purpose of this invention is to provide a room-temperature biomimetic reductive dehalogenation suspension system, its preparation method, and its application, which solves the problems of complex material preparation, harsh reaction conditions, and low efficiency in the prior art.

[0005] This invention is achieved through the following technical solutions:

[0006] A room-temperature biomimetic reductive dehalogenation suspension system is formed by mixing nitrogen-rich biochar, green rust, and cobalt hydroxide in an aqueous phase at a mass ratio of 1:(1~5):(0.8~3.8) at room temperature. The green rust is a layered Fe(II)–Fe(III) hydroxide. The nitrogen-rich biochar is bone char prepared from animal bone, providing nitrogen functional groups to simulate the enzyme ligand environment. The green rust provides reducing iron species to participate in electron transfer. The cobalt hydroxide provides cobalt active centers, which combine with the nitrogen functional groups in the bone char to construct a cobalamin-like structure. This system exhibits excellent reductive dehalogenation activity under ambient temperature (15~30℃), atmospheric pressure, and aqueous suspension conditions.

[0007] Therefore, this invention also protects the application of the above-mentioned room-temperature biomimetic reductive dehalogenation suspension system in the reductive dehalogenation of pollutants. It can be used alone for pollution remediation, or as a functional component of a microbial-material hybrid, working synergistically with dehalogenation microorganisms.

[0008] The pollutants are halogenated organic compounds such as trichloroethylene, hexachlorobutadiene, 1,2-dichloroethylene and monochloroethylene.

[0009] The concentration of the pollutant is 20 μM-100 μM.

[0010] The active hydrogen generated by the system described in this invention can directionally reduce acetylene to ethylene and ethane. Therefore, this invention also protects the application of the above-mentioned room-temperature biomimetic reduction dehalogenation suspension system in the directional reduction of acetylene to ethylene and ethane.

[0011] A method for remediating soil or groundwater contaminated with halogenated hydrocarbons, wherein the ambient temperature biomimetic reduction dehalogenation suspension system is injected into the contaminated area, the reaction time is 50 minutes to 2 hours, and then samples are taken to test the concentration of pollutants. Remediation is completed when the concentration meets the standard.

[0012] The preparation method of the room-temperature biomimetic reductive dehalogenation suspension system is as follows:

[0013] (1) Disperse nitrogen-rich biochar in deionized water to prepare a 5-20 g / L nitrogen-rich biochar suspension;

[0014] (2) Mix Fe(II) and Fe(III) salt solutions under anaerobic conditions, adjust the pH to 7.5-8.5, and prepare a green rust suspension (GR) containing 50-70 mM of divalent iron and 25-35 mM of trivalent iron.

[0015] (3) Disperse cobalt sulfate heptahydrate powder in deionized water and adjust the pH to 8.5 with sodium hydroxide to form a 250-300mM cobalt hydroxide suspension (Co(OH)2).

[0016] (4) Mix the above three suspensions in proportion to form a room temperature reduction dehalogenation system.

[0017] Preferably, the volume ratio of the three suspensions in step (4) is: bone char (BC): green rust (GR): cobalt hydroxide (Co(OH)2) = 1:(4~7):(0.25~1.5).

[0018] The preparation method of the room temperature biomimetic reduction dehalogenation suspension system further includes the following method: combining the above steps (2) and (3) into one step, in the process of adding divalent iron and trivalent iron solution in the preparation of green rust suspension in step (2), 16 mL of 0.5 mol / L CoSO4 is added simultaneously, with a molar ratio of Fe 2+ :Fe 3+ :Co 2+ =2:1:2, adjust pH to 7.5-8.5 to obtain GR-Co suspension, and then mix it with bone carbon suspension prepared in step (1) at room temperature to form a reduction dehalogenation system.

[0019] The beneficial effects of this invention are as follows:

[0020] 1. The reaction of this invention can efficiently dehalogenate at room temperature without heating or high pressure. All components of this invention are aqueous suspensions, which can be used immediately after mixing. The preparation process is simple and does not require high-temperature doping or complex synthesis. Compared with chemical reduction dehalogenation systems, this invention adopts a biomimetic design to simulate the active center structure of biological dehalogenases. The carbon-cobalt material mediates the transfer of ferrous electrons to generate active hydrogen. The active hydrogen can be further stably adsorbed in cobalt atoms or the nitrogen structure of biochar to achieve efficient reduction dehalogenation and has biomimetic catalytic properties. Green rust can form a heterojunction with cobalt hydroxide or be directly adsorbed in the nitrogen structure of bone char, making the reaction efficient and having enzyme-like catalytic properties. This solves the problems of complex material preparation, harsh reaction conditions, and low efficiency in the prior art.

[0021] 2. This invention can completely reduce 20 μM trichloroethylene to acetylene, ethylene, and ethane within 50 minutes, with a dehalogenation rate approaching 100% and a trichloroethylene degradation kinetic constant of 0.31 min. -1 Compared with the mainstream reductive dehalogenation system, the kinetic constant is increased by about 2–3 orders of magnitude;

[0022] 3. The materials used in this invention are widely available and low in cost, suitable for in-situ injection repair, and produce no toxic byproducts;

[0023] 4. This invention can not only simulate the structure of cobalamin to achieve dehalogenation of pollutants, but also couple with a microbial dehalogenation system to construct a "material-enzyme" hybrid system and improve the overall remediation efficiency.

[0024] 5. The active hydrogen generated in the reaction system of this invention can directionally reduce acetylene to ethylene and ethane under mild reaction conditions, providing a new approach for the industrial production of ethylene.

[0025] In summary, the preparation process of this invention is simple. It utilizes the nitrogen functional groups in nitrogen-rich biochar to synergistically construct a cobalamin-like structure with cobalt hydroxide, thereby generating and stabilizing active hydrogen in situ. Green rust provides reducing iron species that participate in electron transfer and can form heterojunctions with cobalt hydroxide or be directly adsorbed into the nitrogen structure of bone char, enabling the reaction to proceed efficiently. It possesses enzyme-like catalytic properties, achieving efficient reduction and dehalogenation of halogenated organic pollutants such as trichloroethylene, and the reaction conditions are mild. At the same time, it can directionally convert acetylene into ethylene and ethane. Attached Figure Description

[0026] Figure 1 This is a comparison chart of dehalogenation efficiency of different systems in Example 4; where BC refers to the system prepared in Comparative Example 1, GR refers to the system prepared in Comparative Example 2, Co(OH)2 refers to the system prepared in Comparative Example 3, Co(OH)2+BC refers to the system prepared in Comparative Example 4, GR+Co(OH)2 refers to the system prepared in Comparative Example 5, GR+BC refers to the system prepared in Comparative Example 6; GR+Co(OH)2+BC refers to the GR+Co(OH)2+BC dehalogenation system prepared in Example 1.

[0027] Figure 2 In Example 5, different dehalogenation systems were used in different Fe... 2+ The graph shows the product percentages after dehalogenation at different concentrations of trichloroethylene (TCE); where A represents GR+BC, referring to the system prepared in Comparative Example 6; B represents GR-Co+BC, referring to the system prepared in Example 2; C represents GR+Co+BC, referring to the system prepared in Example 3; and D represents GR+Co(OH)2+BC, referring to the system prepared in Example 1.

[0028] Figure 3 This is a comparison chart of the dehalogenation effects of different dehalogenation systems in the cyclic experiment in Example 6; where a is GR+BC, referring to the system prepared in Comparative Example 6, and b is GR+Co(OH)2+BC, which is the dehalogenation system prepared in Example 1.

[0029] Figure 4 This is a graph showing the concentration changes of the mixed gas (acetylene, ethylene, ethane) under the dehalogenation system in Example 7.

[0030] Figure 5These are scanning electron microscope (SEM) images of materials prepared by different combinations; where (a) GR refers to the system prepared in Comparative Example 2; (b) Co(OH)2 refers to the system prepared in Comparative Example 3; (c) BC refers to the system prepared in Comparative Example 1; (d) Co(OH)2+BC refers to the system prepared in Comparative Example 4; (e) GR+ Co(OH)2 refers to the system prepared in Comparative Example 5; (f) GR+ Co(OH)2+BC refers to the GR+Co(OH)2+BC dehalogenation system prepared in Example 1; and (g) GR+BC refers to the system prepared in Comparative Example 6.

[0031] Figure 6 These are X-ray diffraction (XRD) comparison diagrams of materials prepared by different combinations; where (a) includes GR, GR+BC, Co(OH)2+BC, GR+ Co(OH)2, and GR+ Co(OH)2+BC, where GR refers to the system prepared in Comparative Example 2, Co(OH)2+BC refers to the system prepared in Comparative Example 4, GR+ Co(OH)2 refers to the system prepared in Comparative Example 5, and GR+ Co(OH)2+BC refers to the GR+Co(OH)2+BC dehalogenation system prepared in Example 1; (b): Co(OH)2 refers to the system prepared in Comparative Example 3.

[0032] Figure 7 This is a schematic diagram of the reaction principle of the biomimetic central structure (cobalt-nitrogen coordination structure). Detailed Implementation

[0033] The following is a further description of the invention, but not a limitation thereof.

[0034] Example 1: Preparation of a room-temperature biomimetic dehalogenation suspension system

[0035] (1) Nitrogen-rich biochar was ground and sieved, then dispersed in deionized water to prepare a bone char suspension (BC) with a concentration of 10 g / L. The specific preparation steps of nitrogen-rich biochar are as follows: Under an inert nitrogen atmosphere (N2, ≥99.9%), carbon-based materials were prepared from bone char using a muffle furnace (LT3 / 11, Nabertherm, Germany). The above raw materials were placed in a 100 ml porcelain crucible and sealed with a tight lid. During pyrolysis, the temperature was increased to 950 °C at a rate of 150 °C / h and maintained at this temperature for one hour. The nitrogen flow rate was maintained at 300 L / h throughout the process. After pyrolysis, the crucible was removed from the muffle furnace and allowed to cool naturally to room temperature. After cooling, the mixture was ground in a ball mill at a speed of 300 rpm for 15 minutes for subsequent use.

[0036] (2) FeSO4 solution and Fe2(SO4)3 solution were mixed at a molar ratio of 2:1 under anaerobic conditions, and the pH was adjusted to 8.5 to prepare a solution containing 60 mM Fe. 2+Green rust suspension (GR). The specific preparation steps are as follows: 400 mL of deionized water was purged with high-purity nitrogen for 1 hour with continuous stirring. 16 mL of 0.5 mol / L FeSO4 solution and 20 mL of 0.2 mol / L Fe2(SO4)3 solution were added, and the pH was adjusted to 8.5 with 1.0 mol / L NaOH solution. During this process, layered iron oxides precipitated out. After the addition of chemicals, the mixture was allowed to stand for 1 hour, then the supernatant was removed, centrifuged, and the supernatant was discarded. The mixture was then washed with deoxygenated distilled water. This centrifugation and washing process was repeated three times. 100 mL of deoxygenated distilled water was added to the remaining solid to obtain a solution containing 60 mMFe. 2+ Sulfate green rust suspension.

[0037] (3) Disperse cobalt sulfate heptahydrate powder in deionized water, adjust the pH to 8.5 with sodium hydroxide, and form a solution containing 300 mM Co. 2+ A stable cobalt hydroxide suspension (Co(OH)2). The specific preparation steps are as follows:

[0038] Take 60 mL of 0.5 mol / L CoSO4 and purge it with high-purity nitrogen for 1 h. Then adjust the pH to 8.5 with 1.0 mol / L NaOH solution. During this process, layered cobalt oxide will crystallize and precipitate out. After standing and allowing the precipitation to stand, a solution containing 300 mM Co is obtained. 2+ A sulfate cobalt hydroxide suspension.

[0039] (4) Take 1 mL of the above-mentioned 10 g / L bone carbon suspension and 5 mL of 60 mM Fe 2+ Green rust suspension and 1 mL containing 300 mM Co 2+ Cobalt hydroxide suspension (Co(OH)2) was mixed at room temperature and diluted to 10 mL with deionized water to form a reduction dehalogenation system, denoted as GR+Co(OH)2+BC dehalogenation system.

[0040] Comparative Example 1:

[0041] Referring to Example 1, the difference is that step (4) is: take 1 mL of the above 10 g / L bone carbon suspension, and dilute it to 10 mL with deionized water to obtain bone carbon suspension, which is denoted as BC system.

[0042] Comparative Example 2:

[0043] Referring to Example 1, the difference is that step (4) is: take 5 mL of the above-mentioned solution containing 60 mM Fe 2+ The green rust suspension was diluted to 10 mL with deionized water and denoted as the GR system.

[0044] Comparative Example 3:

[0045] Referring to Example 1, the difference is that step (4) is: take 1 mL of the above-mentioned solution containing 300 mM Co 2+ The cobalt hydroxide suspension (Co(OH)2) was diluted to 10 mL with deionized water and denoted as the Co(OH)2 system.

[0046] Comparative Example 4:

[0047] Referring to Example 1, the difference is that step (4) is: take 1 mL of the above-mentioned 10 g / L bone carbon suspension and 1 mL of solution containing 300 mM Co 2+ The cobalt hydroxide suspension (Co(OH)2) was diluted to 10 mL with deionized water and denoted as the Co(OH)2+BC system.

[0048] Comparative Example 5:

[0049] Referring to Example 1, the difference is that step (4) is: take 5 mL of the above-mentioned solution containing 60 mM Fe 2+ Green rust suspension and 1 mL containing 300 mM Co 2+ Cobalt hydroxide suspension (Co(OH)2) was mixed at room temperature and diluted to 10 mL with deionized water to form a reduction dehalogenation system, denoted as GR+Co(OH)2 system.

[0050] Comparative Example 6:

[0051] Referring to Example 1, the difference is that step (4) is: take 1 mL of the above-mentioned 10 g / L bone carbon suspension and 5 mL of 60 mM Fe 2+ The green rust suspension was diluted to 10 mL with deionized water and denoted as the GR+BC system.

[0052] Example 2: Dehalogenation systems prepared by different methods of adding cobalt

[0053] Referring to Example 1, the difference is that steps (2) and (3) in Example 1 are combined into one step. During the process of adding ferrous and ferric solutions to the GR solution, 16 mL of 0.5 mol / L CoSO4 is added simultaneously, with a molar ratio of Fe... 2+ :Fe 3+ :Co 2+ =2:1:2, other operations are the same, adjust the pH to 8.5 to obtain GR-Co suspension, then take 1 mL of 10 g / L bone carbon suspension prepared in Example 1 and 5 mL of GR-Co suspension and mix them at room temperature, and make up to 10 mL with deionized water to form a reduction dehalogenation system, which is denoted as GR-Co+BC dehalogenation system.

[0054] Example 3: Dehalogenation systems prepared by different methods of adding cobalt

[0055] Referring to Example 2, the difference is that: after taking 50 mL of the GR suspension synthesized in step (2) of Example 1, 6 mL of 0.5 mol / L CoSO4 was added, with a molar ratio of Fe... 2+ :Fe 3+ :Co 2+ The ratio of the GR+Co suspension to the BC+Co suspension is 2:1:2. The pH is then adjusted to 8.5 with 1.0 mol / L NaOH solution, and the volume is brought up to 60 mL with deionized water to obtain a GR+Co suspension. Then, 1 mL of 10 g / L bone char suspension and 6 mL of GR+Co suspension prepared in Example 1 are mixed at room temperature and brought up to 10 mL with deionized water to form a reductive dehalogenation system, denoted as the GR+Co+BC dehalogenation system.

[0056] Example 4: Trichloroethylene Reduction Dehalogenation Experiment

[0057] The GR+Co(OH)2+BC dehalogenation system prepared in Example 1 and the systems prepared in Comparative Examples 1-6 were added to sealed reaction flasks, respectively. 20 μM trichloroethylene was added, and the reaction temperature was controlled at 25°C. The reaction was allowed to stand or agitated, and the degradation rate was detected. The results are shown in [link to results]. Figure 1 .

[0058] The results showed that neither the iron-free system nor the bone char-free system could degrade pollutants; the system containing only bone char could only perform a certain adsorption function; the GR+BC dehalogenation system prepared in Comparative Example 6 degraded pollutants at a slower rate, while the GR+Co(OH) system in Example 1... 2+ The degradation rate of the BC dehalogenation system was improved.

[0059] Example 5: Product proportions of dehalogenation systems under different concentrations of trichloroethylene (TCE)

[0060] The dehalogenation systems prepared in Examples 1-3 and Comparative Example 6 were added to a sealed reaction flask.

[0061] The above dehalogenation processes were all carried out in 10 mL systems, resulting in a final concentration of 30 mM Fe. 2+ Dehalogenation system. In a system containing 30 mM Fe 2+ In the dehalogenation system, trichloroethylene was added at concentrations of 20 μM, 40 μM, and 100 μM, respectively. To compare the effect of material dosage on the dehalogenation system, the material dosage was reduced to a final concentration containing 6 mM Fe. 2+ The dehalogenation system contains 6 mM Fe 2+ In the dehalogenation system, 100 μM trichloroethylene was added; the reaction temperature was controlled at 25℃ for all reaction systems, and the reaction was repeated three times with shaking. After 72 hours of degradation, the degradation products were detected (see...). Figure 2 ).

[0062] The results showed that at 30 mM Fe 2+ In the GR+Co(OH)2+BC dehalogenation system prepared in Example 1, 20 μM trichloroethylene was completely converted within 60 minutes, with the main products being acetylene and ethane. With increasing time, all products were converted to ethylene and ethane. Furthermore, as the concentration of trichloroethylene increased, the active hydrogen content in the system was insufficient to convert all acetylene, with the main products being acetylene, ethylene, and acetylene again. The proportion of acetylene increased with increasing trichloroethylene concentration. Moreover, different methods of cobalt addition resulted in significant differences in product proportions. It can be seen that the GR-Co+BC dehalogenation system prepared in Example 2 and the GR+Co(OH)2+BC dehalogenation system prepared in Example 1 exhibited more complete dehalogenation in the products. These two methods of cobalt addition may have resulted in different structural features, such as heterojunctions.

[0063] Example 6: System stability and reusability test

[0064] (1) 20 μM trichloroethylene was injected into the GR+Co(OH)2+BC dehalogenation system prepared in Example 1 and the GR+BC dehalogenation system prepared in Comparative Example 6, respectively, and the reaction was carried out in a shaker. During the reaction, the concentration of pollutants in the dehalogenation system was detected.

[0065] (2) After the pollutants are completely degraded, 20 μM trichloroethylene is injected again to continue the reaction. This cycle experiment is repeated 4 times.

[0066] (3) The results show (see Figure 3 After four cycles, compared with the GR+BC dehalogenation system, the GR+Co(OH)2+BC dehalogenation system with added cobalt showed less degradation in removal efficiency, better activity retention, and a higher reaction rate.

[0067] Example 7: Active hydrogen reduces acetylene to ethylene and ethane.

[0068] (1) 15 μL of a mixture of ethane, ethylene, and acetylene (containing 20.3 μM ethane, 21.03 μM ethylene, and 19.77 μM acetylene) was injected into the GR+Co(OH)2+BC dehalogenation system prepared in Example 1 to carry out the reaction;

[0069] (2) After the reaction is complete, the proportion of products is analyzed (see...). Figure 4 The results showed that ethylene and ethane accounted for nearly 100%, indicating that the active hydrogen in this reduction system can efficiently convert acetylene into ethylene and ethane.

[0070] Example 8: Formation of heterojunctions in the system

[0071] The morphology and crystal phase of the materials prepared by different combinations in Example 1 and Comparative Examples 1-6 were characterized by scanning electron microscopy (SEM) and X-ray diffraction (XRD).

[0072] Figure 5 The images (a) to (g) show the scanning electron microscope (SEM) results of the materials (GR, Co(OH)2, BC, Co(OH)2+BC, GR+Co(OH)2, GR+Co(OH)2+BC, GR+BC) prepared by different combinations in Example 1. It can be seen that GR exhibits a regular sheet-like hexagonal structure, Co(OH)2 also exhibits a certain sheet-like structure, and BC can better disperse Co(OH)2.

[0073] From X-ray diffraction (XRD) results (see) Figure 6 As can be seen, unlike Co(OH)₂ in the conventional definition, the Co(OH)₂ synthesized under the conditions of Example 1 has the same crystal phase structure as GR, and its crystallinity is superior, which is more conducive to the assembly and stacking of components to form heterojunctions. The specific mechanism is described in [link to example]. Figure 7 .

[0074] Example 9: Degradation of other halogenated organic pollutants

[0075] Hexachlorobutadiene (644 μM), 1,2-dichloroethylene (20 μM), and monochloroethylene (20 μM) were added to the GR+Co(OH)2+BC dehalogenation system of Example 1, respectively.

[0076] The product composition of hexachlorobutadiene was analyzed after 24 hours of reaction, and the product composition of 1,2-dichloroethylene and monochloroethylene was analyzed after 12 hours of reaction.

[0077] Table 1. Degradation products of hexachlorobutadiene (after 24 hours of reaction)

[0078] Table 2 Degradation products of vinyl chloride (reaction time 12h)

[0079] Table 3 Degradation products of 1,2-dichloroethylene (reaction time 12 h)

[0080] The results showed that the degradation rate of hexachlorobutadiene was 96% after 24 hours (products are shown in Table 1), the degradation rate of monochloroethylene was 77% after 12 hours (products are shown in Table 2), and the degradation rate of 1,2-dichloroethylene was 88% after 12 hours (products are shown in Table 3). The products included a variety of industrially valuable organic chemicals. This indicates that the system can efficiently degrade halogenated organic pollutants such as hexachlorobutadiene, 1,2-dichloroethylene, and monochloroethylene, which are difficult to degrade and for which mature treatment processes are not yet available.

Claims

1. A room-temperature biomimetic reductive dehalogenation suspension system, characterized in that, It is formed by mixing nitrogen-rich biochar, green rust and cobalt hydroxide in an aqueous phase at room temperature in a mass ratio of 1:(1~5):(0.8~3.8). The green rust is a layered Fe(II)–Fe(III) hydroxide. The nitrogen-rich biochar is bone carbon prepared from animal bone, which provides nitrogen functional groups to simulate the enzyme ligand environment. The green rust provides reducing iron species to participate in electron transfer. The cobalt hydroxide provides cobalt active centers, which combine with the nitrogen functional groups in the bone carbon to construct a cobalamin-like structure.

2. The application of the room temperature biomimetic reduction dehalogenation suspension system according to claim 1 in the reduction and dehalogenation of pollutants.

3. The application according to claim 2, characterized in that, The pollutant is one or more of trichloroethylene, hexachlorobutadiene, 1,2-dichloroethylene, and monochloroethylene.

4. The application according to claim 2, characterized in that, The concentration of the pollutant is 20 μM-100 μM.

5. The application of the room-temperature biomimetic reduction dehalogenation suspension system according to claim 1 in the directional reduction of acetylene to ethylene and ethane.

6. A method for remediating soil or groundwater contaminated with halogenated hydrocarbons, characterized in that, Inject the ambient temperature biomimetic reduction dehalogenation suspension system described in claim 1 into the contaminated area. The remediation is completed when the reaction time reaches the target within 50 minutes to 2 hours.

7. The method for preparing the room-temperature biomimetic reductive dehalogenation suspension system according to claim 1, characterized in that, The steps are as follows: (1) Disperse nitrogen-rich biochar in deionized water to prepare a 5-20 g / L nitrogen-rich biochar suspension; (2) Mix Fe(II) and Fe(III) salt solutions under anaerobic conditions, adjust the pH to 7.5-8.5, and prepare a green rust suspension containing 50-70 mM ferrous iron and 25-35 mM ferric iron; (3) Disperse cobalt sulfate heptahydrate powder in deionized water, and adjust the pH to 8.5 with sodium hydroxide to form a 250-300mM cobalt hydroxide suspension; (4) Mix the above three suspensions in proportion to form a room temperature reduction dehalogenation system.

8. The preparation method according to claim 7, characterized in that, The volume ratio of the three suspensions in step (4) is: bone char: green rust: cobalt hydroxide = 1:(4~7):(0.25~1.5).

9. The method for preparing the room-temperature biomimetic reductive dehalogenation suspension system according to claim 1, characterized in that, The method includes the following: during the preparation of the green rust suspension in step (2), when adding ferrous and ferric solutions, 16 mL of 0.5 mol / L CoSO4 is added simultaneously, with a molar ratio of Fe... 2+ :Fe 3+ :Co 2+ =2:1:2, adjust pH to 7.5-8.5 to obtain GR-Co suspension, and then take the bone carbon suspension prepared in step (1) of claim 7 and mix it with GR-Co suspension at room temperature to form a reduction dehalogenation system.

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