A method for in-situ removal of phenolic pollutants by freeze-strengthened persulfate

Abstract

The application discloses a method for removing phenolic pollutants in situ by frozen reinforced persulfate, which accelerates the removal of trace phenolic pollutants in soil or groundwater through the creation of ice crystal interface under natural low-temperature freezing conditions and the physical and chemical effects of ice freezing and concentration. The application is characterized in that only manganese oxide (such as beta-type manganese dioxide (beta-MnO2), gamma-type manganese dioxide (gamma-MnO2) and delta-type manganese dioxide (delta-MnO2)) needs to be added to soil or groundwater before the freezing season, and a persulfate (PS) solution is injected to build a manganese oxide-persulfate system. After freezing, the manganese oxide will form a high-activity surface complex MnO2-PS with the persulfate molecules * The complex can accelerate the removal of phenolic pollutants such as bisphenol A and 2,4-dichlorophenol through electron transfer. The technology is simple, efficient, environmentally friendly and low-cost, and is suitable for the removal of trace pollutants in high-altitude and high-cold areas.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of soil or groundwater remediation, and relates to a phenolic pollutant removal technology, in particular to a method for in-situ removal of phenolic pollutants in soil and groundwater by using natural freezing to strengthen manganese oxide to activate persulfate. BACKGROUND

[0002] At present, scientists have found a large number of phenolic pollutants in some high-latitude or high-altitude areas with less human activity. Compared with climate suitable areas, the ecosystems in high-latitude or high-altitude areas are more fragile and sensitive, and it is more difficult to implement pollution remediation due to the existence of a long low-temperature freezing period. In order to solve this problem, it is urgent to develop a simple and effective, low-cost pollution control technology in high-cold environment.

[0003] Among the currently widely used chemical oxidation technologies, in-situ chemical oxidation (ISCO) technology has become one of the preferred remediation technologies for contaminated soil and groundwater due to its simple operation, low cost, strong applicability and other characteristics. Potassium permanganate, hydrogen peroxide, persulfate (PS) and other chemical oxidants are the basis of ISCO. Among them, persulfate has attracted more and more attention due to its stable nature (long half-life in groundwater), easy storage and transportation (in solid form), good water solubility and other advantages. Previous studies have found that PS can be activated by mineral components in soil, such as naturally occurring iron and manganese oxides, to generate highly active oxidizing species, which can then achieve the degradation of phenolic pollutants in soil or groundwater. However, despite this, the in-situ chemical oxidation technology based on persulfate still faces the following limitations in practical application in high-cold areas: (1) Low-temperature freezing will slow down or even terminate the chemical reaction; (2) The reaction is greatly affected by pH, and iron and manganese oxides have better effect on activating PS to remove pollutants under acidic conditions, but the effect of activating PS to remove pollutants under near-neutral environmental pH conditions is greatly reduced; (3) Generally, the active oxidizing species generated by iron and manganese oxides activating PS mainly include sulfate radical (SO4 ·– ), hydroxyl radical (HO · ) and other radical species, which have strong oxidation ability, but poor selective degradation ability for target pollutants, insufficient anti-interference ability, and are easily quenched by a large number of coexisting anions and cations and humic acid and other substances in the environment. SUMMARY

[0004] In order to deal with the difficulty of remediation of contaminated soil or groundwater under low temperature conditions in high-cold regions, and based on the limitation of in-situ chemical oxidation technology based on persulfate that the activity is insufficient under environmental pH conditions, the selective difference of active oxidizing species is poor, and the anti-interference ability is insufficient, unlike the traditional idea of strengthening in-situ chemical oxidation technology by developing new functional materials, increasing the dosage of oxidant, providing additional energy, or adjusting pH by adding chemical agents, the application takes the advantage of the limitation of frozen environment, fully utilizes the ice crystal interface microenvironment generated after freezing to strengthen the activation of manganese oxide on persulfate, and then enhances the in-situ removal efficiency of phenolic pollutants.

[0005] The purpose of the application is to provide a method for in-situ removal of phenolic pollutants by frozen-strengthened persulfate, after adding manganese oxide and persulfate into contaminated soil or groundwater, the natural freezing is utilized to automatically adjust the microenvironment pH without adding acid or alkali reagents, and then the ability of manganese oxide to activate persulfate is strengthened, and the in-situ efficient removal of phenolic pollutants is realized. The key of the application lies in that (1) the ice crystal interface generated after water freezing is used as a limited micro-reaction zone, in which H + Ions will gather at the ice crystal interface, so that the local pH is reduced, and the activity of manganese oxide to activate persulfate is significantly improved. (2) The enrichment and concentration of manganese oxide, persulfate and phenolic pollutants at the ice crystal interface not only facilitate the adsorption of manganese oxide to the PS surface to form a MnO2-PS * surface complex with high activity and high selectivity, but also accelerates the mass transfer between pollutants and active species. After contacting with pollutants, MnO2-PS * can remove pollutants through a direct electron transfer process. The method can be used for the removal of phenolic pollutants such as bisphenol A and 2,4-dichlorophenol in frozen soil or groundwater.

[0006] The specific technical solutions for achieving the purpose of the application are as follows:

[0007] A method for in-situ removal of phenolic pollutants by frozen-strengthened persulfate, the method comprising the following steps:

[0008] Step 1: 1-15 days before the arrival of freezing weather, manganese oxide is added to the contaminated soil or groundwater, so that the soil or groundwater contains 200-4000 mg / kg or 0.2-4.0 g / L of manganese oxide, if the natural content of manganese oxide in the soil or groundwater meets the concentration requirement, no manganese oxide is added;

[0009] Step 2: Injecting persulfate into the soil or groundwater containing manganese oxide in step 1, after the soil or groundwater is frozen (freezing temperature range is 0~ -80℃), the manganese oxide activates the persulfate to generate high-activity MnO2-PS* surface complex within 0.5-4 hours of reaction time to achieve the oxidative removal of phenolic pollutants in the soil or groundwater; the amount of persulfate added to the soil or groundwater is 100~1000mg / kg or 0.5~4mmol / L; the molar ratio of manganese oxide to persulfate is 2~4:1;

[0010] Wherein:

[0011] The pH value of the soil or groundwater is 5.0~8.0; the depth range is from the ground to 20 meters underground;

[0012] The phenolic pollutants include 2,4-dichlorophenol (2,4-DCP), bisphenol A (BPA) and the like; the concentration range of the phenolic pollutants is 0.5mg / kg~30mg / kg or 5μmol / L~300μmol / L.

[0013] Further, the manganese oxide is β-type manganese dioxide (β-MnO2), γ-type manganese dioxide (γ-MnO2) or δ-type manganese dioxide (δ-MnO2).

[0014] Further, the contaminated soil or groundwater should contain 200~4000mg / kg or 0.2g / L~4.0g / L of manganese oxide, if the natural content of manganese oxide in the soil or groundwater meets the concentration requirement, additional addition is not necessary.

[0015] Further, the amount of persulfate added to the soil or groundwater to be repaired is 100~1000mg / kg or 0.5mmol / L~4mmol / L. If based on manganese oxide, the ratio of manganese oxide to persulfate should be 2~4:1.

[0016] Further, the persulfate includes monopersulfate compound (PMS) and peroxymonosulfate (PDS).

[0017] Further, the order of addition of manganese oxide and persulfate is to add manganese oxide first and then add persulfate, or to add both at the same time.

[0018] The present application is mainly developed for in-situ remediation of contaminated soil and groundwater in frozen environment. The core principle is to utilize the natural frozen state to promote the enrichment and concentration of H + , manganese oxide, persulfate and pollutants on the ice crystal interface. This process not only accelerates the adsorption of manganese oxide to the surface of persulfate molecules, but also promotes the generation of high-activity MnO2-PS *The surface complex can significantly enhance the efficiency of electron transfer between the pollutants and the complex, thereby promoting the in-situ oxidative removal of the pollutants. The present application develops an in-situ remediation technology suitable for frozen conditions, enhances the pollution removal capacity of the MnO2-PS system, and provides a cost-effective and green solution for environmental remediation in high-cold regions, which has broad application potential in pollution control in frozen environments.

[0019] Compared with the prior art, the present application has the following advantages and beneficial effects:

[0020] 1) The present application is suitable for pollution remediation in low-temperature frozen environments, fully utilizes the reaction characteristics of the frozen environment in high-cold regions, automatically adjusts the microenvironment pH without relying on additional reagents, improves the oxidation capacity of manganese oxide and its ability to activate PS, and does not require additional acid or base reagents or energy, thereby reducing reagent costs and energy consumption.

[0021] 2) The present application has high activity and selectivity. In the frozen environment, manganese oxide is adsorbed to the surface of PS and forms a surface complex with high activity and selectivity. The generation of this surface complex promotes the oxidative degradation of pollutants through direct electron transfer. This technology enhances the environmental disturbance resistance of in-situ chemical oxidation technology based on persulfate and improves the removal selectivity of electron-rich phenolic organic pollutants. It is suitable for the removal of phenolic pollutants such as bisphenol A and 2,4-dichlorophenol in frozen soil or groundwater. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 Effect diagram of the removal of bisphenol A in the frozen accelerated soil by the beta-MnO2-PDS system of Example 1 and Comparative Example 1;

[0023] Figure 2 Effect diagram of the removal of bisphenol A in the frozen accelerated groundwater by the beta-MnO2-PDS system of Example 2 and Comparative Example 2;

[0024] Figure 3 Effect diagram of the removal of 2,4-dichlorophenol by the beta-MnO2-PDS system of Example 3 and Comparative Example 3;

[0025] Figure 4 Effect diagram of the removal of 2,4-dichlorophenol by the gamma-MnO2-PDS system of Example 4 and Comparative Example 4;

[0026] Figure 5 Effect diagram of the removal of 2,4-dichlorophenol by the delta-MnO2-PMS system of Example 5 and Comparative Example 5. DETAILED DESCRIPTION

[0027] In order to better understand the content of the present application, the technical solutions of the present application are further illustrated below through specific examples and drawings. However, these examples do not limit the protection scope of the present application.

[0028] Example 1

[0029] Step 1, respectively prepare peroxodisulfate reaction solution with a concentration of 100 mmol / L and bisphenol A reaction solution with a concentration of 5 mmol / L;

[0030] Step 2, take 500 μL of the bisphenol A reaction solution prepared in step 1 into a saturated solution containing 25 g of soil to simulate contaminated soil;

[0031] Step 3, add 0.03 g of β-MnO2 powder to the mixture in step 2 for mixing;

[0032] Step 4, take 2 mL of the peroxodisulfate reaction solution prepared in step 1 into the mixture in step 3; then adjust the initial pH value of the mixture to the natural pH (about 6.5);

[0033] Step 5, divide the mixture in step 4 into multiple conical tubes, and immerse the conical tubes in a -20℃ ethylene glycol ice water bath to freeze the reaction system (the purpose of selecting -20℃ condition is to make the reaction under frozen conditions, which has no influence on the reaction mechanism and the effect of removing pollutants, therefore, the experimental results of different frozen temperature ranges are not shown, the same as the following examples, which will not be illustrated again). The reaction time starts from the moment when the conical tube containing the sample is immersed in the ethylene glycol solution, and the sample is taken at different time points (20, 40, 80 minutes) respectively, and then the concentration of the pollutant is detected by using a high performance liquid chromatograph.

[0034] Comparative Example 1

[0035] Step 1, respectively prepare peroxodisulfate reaction solution with a concentration of 100 mmol / L and bisphenol A reaction solution with a concentration of 5 mmol / L;

[0036] Step 2, take 500 μL of the bisphenol A reaction solution prepared in step 1 into a saturated solution containing 25 g of soil to simulate contaminated soil;

[0037] Step 3, add 0.03 g of β-MnO2 powder to the mixture in step 2 for mixing;

[0038] Step 4, take 2 mL of the peroxodisulfate reaction solution prepared in step 1 into the mixture in step 3; then adjust the initial pH value of the mixture to the natural pH (about 6.5).

[0039] Step 5, the mixed solution in step 4 is reacted at room temperature (25℃), and the reaction time is counted from the time when the mixed solution is adjusted to the target pH value; samples are taken at different time points (20, 40, 80 minutes) respectively, and then the concentration of pollutants is detected by using a high performance liquid chromatograph.

[0040] Referring to Figure 1 The effect of freezing on the removal of bisphenol A by the β-MnO2-PDS system in soil is shown in the graph of Example 1 and Comparative Example 1. As can be seen from the graph, under the condition of -20℃ freezing, the removal rate of bisphenol A by the MnO2 / PDS system can reach 61% within 80 minutes; while under the condition of 25℃ solution, the removal rate of bisphenol A is only 23% within 80 minutes. For details, see Figure 1 The effect of freezing on the removal of bisphenol A by the β-MnO2-PDS system in soil is shown in the graph of Example 1 and Comparative Example 1. As can be seen from the graph, under the condition of -20℃ freezing, the removal rate of bisphenol A by the MnO2 / PDS system can reach 61% within 80 minutes; while under the condition of 25℃ solution, the removal rate of bisphenol A is only 23% within 80 minutes. For details, see The removal rate curve of bisphenol A under the condition of solution is shown in the graph, The removal rate curve of bisphenol A under the condition of freezing is shown in the graph.

[0041] Example 2

[0042] Step 1, prepare sodium peroxodisulfate reaction solution with a concentration of 100 mmol / L and bisphenol A reaction solution with a concentration of 5 mmol / L respectively;

[0043] Step 2, take 500 μL of the bisphenol A reaction solution prepared in step 1 into 47.5 mL of groundwater to simulate contaminated groundwater;

[0044] Step 3, add 0.03 g of β-MnO2 powder to the mixed solution in step 2 and mix;

[0045] Step 4, take 2 mL of the sodium peroxodisulfate reaction solution prepared in step 1 into the mixed solution in step 3; then adjust the initial pH value of the mixed solution to the natural pH value (about 6.5).

[0046] Step 5, divide the mixed solution in step 4 into multiple conical tubes, and immerse the conical tubes in a -20℃ ethylene glycol ice water bath to make the reaction system freeze. The reaction time is counted from the moment when the conical tubes containing the sample are immersed in the ethylene glycol solution, and samples are taken at different time points (20, 40, 80 minutes) respectively, and then the concentration of pollutants is detected by using a high performance liquid chromatograph.

[0047] Comparative Example 2

[0048] Step 1, prepare sodium peroxodisulfate reaction solution with a concentration of 100 mmol / L and bisphenol A reaction solution with a concentration of 5 mmol / L respectively;

[0049] Step 2, 500 μL of the prepared bisphenol A solution in step 1 was taken in 47.5 mL of groundwater to simulate the contaminated groundwater;

[0050] Step 3, 0.03 g of β-MnO2 powder was added to the mixture in step 2 and mixed;

[0051] Step 4, 2 mL of the prepared sodium peroxodisulfate solution in step 1 was taken in the mixture in step 3; then the initial pH value of the mixture was adjusted to the natural pH (about 6.5).

[0052] Step 5, the mixture in step 4 was placed in a normal temperature (25℃) condition for reaction, the reaction time was counted from the time when the pH value of the mixture was adjusted to the target pH value, and samples were taken at different time points (20, 40, 80 minutes) respectively, then the concentration of the pollutants was detected by using a high performance liquid chromatograph.

[0053] Referring to Figure 2 , the effect diagram of the ice accelerated removal of bisphenol A by the β-MnO2-PDS system in groundwater in Example 2 and Comparative Example 2 is shown in the figure, it can be seen from the figure that under the condition of -20℃ ice, the removal rate of bisphenol A by the MnO2 / PDS system can reach 76% within 80 minutes; while under the condition of 25℃ solution, the removal rate of bisphenol A within 80 minutes is only 28%. See Figure 2 , the effect of ice on the removal of bisphenol A by the MnO2 / PMS system under the conditions of 25℃ aqueous solution and -20℃ ice is shown in the figure, , the removal rate curve of bisphenol A under the condition of solution is shown in the figure, , the removal rate curve of bisphenol A under the condition of ice is shown in the figure.

[0054] Example 3

[0055] Step 1, sodium peroxodisulfate solution with a concentration of 100 mmol / L and 2,4-dichlorophenol solution with a concentration of 5 mmol / L were respectively prepared;

[0056] Step 2, 500 μL of the prepared bisphenol A solution in step 1 was taken in 48.5 mL of ultrapure water;

[0057] Step 3, 0.015 g of β-MnO2 powder was added to the mixture in step 2 and mixed;

[0058] Step 4, 1 mL of the prepared sodium peroxodisulfate solution in step 1 was taken in the mixture in step 3; then the initial pH value of the mixture was adjusted to the natural pH (about 6.5).

[0059] Step 5, the mixture in step 4 was divided into multiple conical tubes and immersed in an ethylene glycol ice water bath at -20°C to freeze the reaction system. The reaction time was counted from the moment the conical tube containing the sample was immersed in the ethylene glycol solution, and samples were taken at different time points (40, 100, 150 minutes), and then the concentration of pollutants was detected using a high performance liquid chromatograph.

[0060] Comparative Example 3

[0061] Step 1, respectively prepare a sodium peroxodisulfate reaction solution with a concentration of 100 mmol / L and a 2,4-dichlorophenol reaction solution with a concentration of 5 mmol / L;

[0062] Step 2, take 500 μL of the bisphenol A reaction solution prepared in step 1 into 48.5 mL of ultrapure water;

[0063] Step 3, add 0.015 g of β-MnO2 powder to the mixture in step 2 and mix;

[0064] Step 4, take 1 mL of the sodium peroxodisulfate reaction solution prepared in step 1 into the mixture in step 3, and then adjust the initial pH value of the mixture to the natural pH (about 6.5);

[0065] Step 5, place the mixture in step 4 in a normal temperature (25°C) condition for reaction, and the reaction time is counted from the moment the mixture is adjusted to the target pH value, and samples are taken at different time points (20, 40, 80 minutes), and then the concentration of pollutants is detected using a high performance liquid chromatograph.

[0066] Reference Figure 3 To implement the effect of the ice-accelerated β-MnO2-PDS system on the removal of 2,4-dichlorophenol described in Example 3 and Comparative Example 3, it can be seen from the figure that under the condition of -20°C ice, the removal rate of 2,4-dichlorophenol by MnO2 / PDS can reach 73% within 150 min; while under the condition of 25°C solution, the removal rate of 2,4-dichlorophenol is only 24% within 150 min. See Figure 3 To compare the effects of ice on the removal of 2,4-dichlorophenol by the MnO2 / PMS system under the conditions of 25°C aqueous solution and -20°C ice, the figure shows the removal rate curve of 2,4-dichlorophenol under the condition of solution, the removal rate curve of 2,4-dichlorophenol under the condition of ice.

[0067] Example 4

[0068] Step 1, respectively prepare a sodium peroxodisulfate reaction solution with a concentration of 100 mmol / L and a 2,4-dichlorophenol reaction solution with a concentration of 5 mmol / L;

[0069] Step 2, 500 μL of 2,4-dichlorophenol prepared in step 1 was taken in 48.5 mL of ultrapure water;

[0070] Step 3, 0.015 g of γ-MnO2 powder was added to the mixture in step 2 and mixed;

[0071] Step 4, 1 mL of sodium peroxodisulfate prepared in step 1 was taken in the mixture in step 3; then the initial pH of the mixture was adjusted to the natural pH (about 6.5);

[0072] Step 5, the mixture in step 4 was divided into multiple conical tubes and the conical tubes were immersed in an ethylene glycol ice water bath at -20°C to freeze the reaction system. The reaction time was started from the moment when the conical tubes containing the sample were immersed in the ethylene glycol solution, and samples were taken at different time points (40, 100, 150 minutes), and then the concentration of pollutants was detected using a high performance liquid chromatograph.

[0073] Comparative Example 4

[0074] Step 1, sodium peroxodisulfate reaction solution with a concentration of 100 mmol / L and 2,4-dichlorophenol reaction solution with a concentration of 5 mmol / L were prepared respectively;

[0075] Step 2, 500 μL of 2,4-dichlorophenol prepared in step 1 was taken in 48.5 mL of ultrapure water;

[0076] Step 3, 0.015 g of γ-MnO2 powder was added to the mixture in step 2 and mixed;

[0077] Step 4, 1 mL of sodium peroxodisulfate prepared in step 1 was taken in the mixture in step 3; then the initial pH of the mixture was adjusted to the natural pH (about 6.5);

[0078] Step 5, the mixture in step 4 was placed in a normal temperature (25°C) condition for reaction, the reaction time was started from the moment when the mixture was adjusted to the target pH, and samples were taken at different time points (40, 100, 150 minutes), and then the concentration of pollutants was detected using a high performance liquid chromatograph.

[0079] Reference Figure 4 The effect diagram of the ice freezing accelerated γ-MnO2-PDS system for removing 2,4-dichlorophenol described in Example 4 and Comparative Example 4 is shown in the figure, from which it can be seen that under the condition of -20°C freezing, the removal rate of 2,4-dichlorophenol by MnO2 / PDS can reach 50% within 150 min; while under the condition of 25°C solution, the removal rate of 2,4-dichlorophenol is only 15% within 150 min. See Figure 4The effect of freezing on the removal of 2,4-dichlorophenol by the MnO2 / PMS system was compared under the conditions of a 25℃ aqueous solution and -20℃ freezing, and the figure shows The removal rate curve of 2,4-dichlorophenol under solution conditions is shown in the figure, The removal rate curve of 2,4-dichlorophenol under freezing conditions is shown in the figure.

[0080] Example 5

[0081] Step 1: Prepare a reaction solution of a monopersulfate compound with a concentration of 100 mmol / L and a 2,4-dichlorophenol reaction solution with a concentration of 5 mmol / L, respectively;

[0082] Step 2: Take 500 μL of the 2,4-dichlorophenol reaction solution prepared in Step 1 into 48.5 mL of ultrapure water;

[0083] Step 3: Add 0.015 g of δ-MnO2 colloid to the mixture in Step 2 and mix;

[0084] Step 4: Take 1 mL of the monopersulfate compound reaction solution prepared in Step 1 into the mixture in Step 3; then adjust the initial pH value of the mixture to the natural pH (about 6.5);

[0085] Step 5: Divide the mixture in Step 4 into multiple conical tubes, and immerse the conical tubes in a -20℃ ethylene glycol ice-water bath to freeze the reaction system. The reaction time starts from the moment when the conical tube containing the sample is immersed in the ethylene glycol solution, and samples are taken at different time points (40, 100, and 150 minutes), respectively, and then the concentration of the pollutant is detected using a high-performance liquid chromatograph.

[0086] Comparative Example 5

[0087] Step 1: Prepare a reaction solution of a monopersulfate compound with a concentration of 100 mmol / L and a 2,4-dichlorophenol reaction solution with a concentration of 5 mmol / L, respectively;

[0088] Step 2: Take 500 μL of the 2,4-dichlorophenol reaction solution prepared in Step 1 into 48.5 mL of ultrapure water;

[0089] Step 3: Add 0.015 g of δ-MnO2 colloid to the mixture in Step 2 and mix;

[0090] Step 4: Take 1 mL of the monopersulfate compound reaction solution prepared in Step 1 into the mixture in Step 3; then adjust the initial pH value of the mixture to the natural pH (about 6.5);

[0091] Step 5, the mixture in step 4 is placed in normal temperature (25℃) condition for reaction, the reaction time is counted from the time when the mixture is adjusted to the target pH, and the samples are taken at different time points (40, 100, 150 minutes) respectively, and then the concentration of pollutants is detected by using a high performance liquid chromatograph.

[0092] Referring to Figure 5 The effect of the ice accelerated δ-MnO2-PMS system on the removal of 2,4-dichlorophenol is shown in the graph of Example 5 and Comparative Example 5. As can be seen from the graph, under the condition of -20℃ ice, the removal rate of 2,4-dichlorophenol by MnO2 / PDS can reach 100% within 150 minutes; while under the condition of 25℃ solution, the removal rate of 2,4-dichlorophenol only reaches 25% within 150 minutes. See Figure 5 The effect of ice on the removal of 2,4-dichlorophenol by the MnO2 / PMS system is compared between 25℃ aqueous solution and -20℃ ice, and the graph shows that The removal rate curve of 2,4-dichlorophenol under the condition of solution is shown in the graph, The removal rate curve of 2,4-dichlorophenol under the condition of ice is shown in the graph.

Claims

1. A method for in-situ removal of phenolic contaminants using freeze-enhanced persulfate, characterized in that, The method includes the following steps: Step 1: 1 to 15 days before the arrival of freezing weather, add manganese oxide to the contaminated soil or groundwater to make the soil or groundwater contain 200 to 4000 mg / kg or 0.2 to 4.0 g / L of manganese oxide. If the natural content of manganese oxide in the soil or groundwater meets the concentration requirements, no addition is needed. Step 2: Inject persulfate into the soil or groundwater containing manganese oxides from Step 1. After the soil or groundwater freezes below 0°C, the manganese oxides activate the persulfate to generate highly reactive MnO2-PS within a reaction time of 0.5-4 hours. * Surface complexes are used to oxidatively remove phenolic pollutants from soil or groundwater; the amount of persulfate added to the soil or groundwater is 100-1000 mg / kg or 0.5-4 mmol / L; the molar ratio of manganese oxide to persulfate is 2-4:

1. in: The pH value of the soil or groundwater is 5.0 to 8.0; the depth range is from the ground surface to 20 meters underground; The phenolic contaminants include 2,4-dichlorophenol and bisphenol A; the concentration range of the phenolic contaminants is 0.5 mg / kg ~ 30 mg / kg or 5 μmol / L ~ 300 μmol / L; The manganese oxide is β-type manganese dioxide, γ-type manganese dioxide, or δ-type manganese dioxide; The persulfates include monopersulfate compounds and perdisulfates.

2. The method according to claim 1, characterized in that, The order of addition of manganese oxide and persulfate is either to add manganese oxide first and then persulfate, or to add both simultaneously.

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