Method for removing semi-volatile organic pollutants in soil through Fenton-like oxidation process

Abstract

The invention relates to a method for removing semi-volatile organic pollutants in soil through a Fenton-like oxidation process. The method comprises the following steps: adding organic acid into polluted soil with a certain water content to prepare an acidic slurry with a pH value of 3-4, then adding alkaline solid peroxides and metal salts into the acidic slurry to obtain a Fenton's-like reaction system, enabling the Fenton's-like reaction system to react with the soil for a certain time under a certain temperature, and removing the organic pollutants in the polluted soil. Compared with theprior art, the method has the advantages of short remediation period of organic polluted soil, excellent pollutant removal effect, low damage to intrinsic physical and chemical properties of the soiland capability of preventing the soil from being acidized.

Description

technical field

[0001] The invention belongs to the field of environmental engineering and relates to a method for removing organic pollutants in soil, in particular to a method for removing organic pollutants in soil by chemical oxidation. Background technique

[0002] According to the "National Soil Pollution Survey Bulletin" jointly issued by the Ministry of Environmental Protection and the Ministry of Land and Resources, the overall state of the soil environment in the country is not optimistic. Secondly; warnings of serious organic pollution are also issued in typical plots such as industrial wasteland, chemical parks, waste incineration and landfills, and oil production areas. Pollutants such as polycyclic aromatic hydrocarbons, petroleum hydrocarbons, and pesticides in organically polluted soils generally have the characteristics of low water solubility, high octanol-water partition coefficient, and electrochemical stability, and are typical refractory and persistent ...

Examples

Embodiment 1

[0035] Removal Effects of Different Organic Acids on Polycyclic Aromatic Hydrocarbons in Fenton’s-like Reaction System

[0036] In PAH-contaminated soil with a moisture content of 30% (the concentrations of anthracene, pyrene, and benzopyrene in the soil are respectively 50mol / kg), a certain amount of organic acid and FeSO 4 , adding H dropwise under constant temperature magnetic stirring 2 o 2 . The amount of organic acid is 0.25mol / kg, FeSO 4 The dosage is 0.12mol / kg, Na 2 CO 4 The dosage is 1.0 mol / kg; the reaction time is 40 minutes, and the reaction temperature is 30°C. The removal effects of the Fenton’S-like reaction system with different organic acids on the removal of PAHs in soil are shown in Table 1.

[0037] Table 1 Removal effect of different organic acids on PAHs in Fenton’S reaction system

[0038]

Embodiment 2

[0040] Influence of Reaction Temperature on Effect of Fenton'S Reaction System in Treating Chemical Plant Contaminated Soil

[0041] Soil samples were collected from a polluted area of ​​a chemical plant. The concentrations of benzo(a)anthracene, benzo(a)pyrene, dibenzo(a,h)anthracene, hexachlorobenzene and chlorobenzene in the soil samples were 15.94 mg / kg, 4.53mg / kg, 5.29mg / kg, 35.24mg / kg, 112.33mg / kg.

[0042] Mix polluted soil with water to make mud with a moisture content of 40%, add Fenton’s reaction system, the amount of humic acid is 0.3mol / kg, FeSO 4 The dosage is 0.3mol / kg, Na 2 CO 4 The dosage is 3.0mol / kg; the reaction is stirred and reacted at 15-60°C for 60min, and the removal rates of various pollutants at different temperatures are shown in Table 2.

[0043] Table 2 The effect of reaction temperature on the effect of Fenton'S-like reaction system on the treatment of chemical plant polluted soil

[0044]

[0045]

Embodiment 3

[0047] Influence of reaction time on the effect of Fenton's reaction system on the treatment of chemical plant polluted soil

[0048] Using the polluted soil sample described in Example 3, the soil is mixed with water to make a slurry with a water content of 40%, and the Fenton's reaction system is added. The amount of humic acid is 0.3mol / kg, FeSO 4 The dosage is 0.3mol / kg, Na 2 CO 4 The dosage is 3.0mol / kg; the reaction is stirred and reacted at 30°C for 30-150min, and the removal rates of various pollutants under different reaction times are shown in Table 3.

[0049] Table 3 The effect of reaction time on the effect of Fenton'S-like reaction system on the treatment of chemical plant polluted soil

[0050]

technical field

[0001] The invention belongs to the field of environmental engineering and relates to a method for removing organic pollutants in soil, in particular to a method for removing organic pollutants in soil by chemical oxidation. Background technique

[0002] According to the "National Soil Pollution Survey Bulletin" jointly issued by the Ministry of Environmental Protection and the Ministry of Land and Resources, the overall state of the soil environment in the country is not optimistic. Secondly; warnings of serious organic pollution are also issued in typical plots such as industrial wasteland, chemical parks, waste incineration and landfills, and oil production areas. Pollutants such as polycyclic aromatic hydrocarbons, petroleum hydrocarbons, and pesticides in organically polluted soils generally have the characteristics of low water solubility, high octanol-water partition coefficient, and electrochemical stability, and are typical refractory and persistent ...

Examples

Embodiment 1

[0035] Removal Effects of Different Organic Acids on Polycyclic Aromatic Hydrocarbons in Fenton’s-like Reaction System

[0036] In PAH-contaminated soil with a moisture content of 30% (the concentrations of anthracene, pyrene, and benzopyrene in the soil are respectively 50mol / kg), a certain amount of organic acid and FeSO 4 , adding H dropwise under constant temperature magnetic stirring 2 o 2 . The amount of organic acid is 0.25mol / kg, FeSO 4 The dosage is 0.12mol / kg, Na 2 CO 4 The dosage is 1.0 mol / kg; the reaction time is 40 minutes, and the reaction temperature is 30°C. The removal effects of the Fenton’S-like reaction system with different organic acids on the removal of PAHs in soil are shown in Table 1.

[0037] Table 1 Removal effect of different organic acids on PAHs in Fenton’S reaction system

[0038]

Embodiment 2

[0040] Influence of Reaction Temperature on Effect of Fenton'S Reaction System in Treating Chemical Plant Contaminated Soil

[0041] Soil samples were collected from a polluted area of ​​a chemical plant. The concentrations of benzo(a)anthracene, benzo(a)pyrene, dibenzo(a,h)anthracene, hexachlorobenzene and chlorobenzene in the soil samples were 15.94 mg / kg, 4.53mg / kg, 5.29mg / kg, 35.24mg / kg, 112.33mg / kg.

[0042] Mix polluted soil with water to make mud with a moisture content of 40%, add Fenton’s reaction system, the amount of humic acid is 0.3mol / kg, FeSO 4 The dosage is 0.3mol / kg, Na 2 CO 4 The dosage is 3.0mol / kg; the reaction is stirred and reacted at 15-60°C for 60min, and the removal rates of various pollutants at different temperatures are shown in Table 2.

[0043] Table 2 The effect of reaction temperature on the effect of Fenton'S-like reaction system on the treatment of chemical plant polluted soil

[0044]

[0045]

Embodiment 3

[0047] Influence of reaction time on the effect of Fenton's reaction system on the treatment of chemical plant polluted soil

[0048] Using the polluted soil sample described in Example 3, the soil is mixed with water to make a slurry with a water content of 40%, and the Fenton's reaction system is added. The amount of humic acid is 0.3mol / kg, FeSO 4 The dosage is 0.3mol / kg, Na 2 CO 4 The dosage is 3.0mol / kg; the reaction is stirred and reacted at 30°C for 30-150min, and the removal rates of various pollutants under different reaction times are shown in Table 3.

[0049] Table 3 The effect of reaction time on the effect of Fenton'S-like reaction system on the treatment of chemical plant polluted soil

[0050]

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