In-situ repairing method of heavy metal polluted soil

Abstract

The invention discloses a method for repairing heavy metal polluted soil, and particularly discloses an in-situ repairing method of heavy metal polluted soil by utilizing compound functional resin and leacheate. The method comprises the following steps: (1) embedding the compound functional resin into heavy metal polluted soil; and (2) wetting the heavy metal polluted soil with the leacheate, wherein the compound functional resin is metal compound loaded ion exchange resin, and the metal compound is zirconium phosphate or zirconium dioxide; and the leacheate is citric acid, sodium acetate, sodium nitride or ammonium nitrate solution. By adopting the method, the soil structure and property are not changed during in-situ soil repairing, and late crop cultivation is facilitated; and the compound functional resin can be recycled, does not generate secondary pollution, can be used for reducing cost and increasing economic benefit, is not influenced by environmental conditions, and is simple in method.

Description

technical field

[0001] The invention relates to a method for remediating heavy metal-contaminated soil, in particular to a method for in-situ repairing heavy metal-contaminated soil by using a composite functional resin combined with eluent. Background technique

[0002] Soil is the foundation of human survival, and soil pollution will have a very bad impact on human production and life. In recent years, incidents of "blood lead", "cadmium rice" and "arsenic poisoning" have occurred continuously, making the problem of soil heavy metal pollution widely concerned by all walks of life. Generally speaking, the problem of soil pollution in my country is becoming more and more serious. According to statistics, about 300 million mu of arable land in my country is polluted by heavy metals, and 12 million tons of grains are polluted by heavy metals every year. In terms of environmental protection, we must focus on the treatment of polluted soil. Heavy metals in the soil can enter th...

Examples

Embodiment 1

[0042] Preparation of ion exchange resin loaded with zirconium phosphate:

[0043]Take by weighing 20g cation exchange resin D001, the massfraction that it is placed in 100mL is the ZrOCl of 5% (calculated as Zr) 2 The solution was fully stirred at 25°C for 20h. Then, filter out the resin particles and add them to 500mL of phosphoric acid solution with a volume fraction of 20%, and react at 60°C. Drying at lower temperature for 5 hours to obtain a composite functional resin with a zirconium loading of 13 wt%.

[0044] Preparation of ion exchange resin loaded with zirconia:

[0045] Take by weighing 50g cation exchange resin D001, it is placed in the ZrOCl of 5% (in terms of Zr) that it is placed in 200mL mass fraction 2 In the solution, react at a constant temperature of 50°C for 4 hours to fully diffuse the zirconium salt to the inner surface of the resin pores, then filter and place it in 1000mL of 5% sodium hydroxide solution, fully stir and react at room temperature for...

Embodiment 2

[0047] The concentration of lead in heavy metal lead polluted soil is 200mg / kg;

[0048] Take 3g of the above polluted soil and put it into a 100mL beaker, then disperse and bury 0.3g of composite functional resin into the polluted soil, then mix 3mL of ammonium nitrate eluent with a concentration of 0.01mol / L with the polluted soil, and mix the above Place the beaker in a horizontal shaker and vibrate for 1 day;

[0049] Wherein, the zirconium loading of the composite functional resin is 12wt%, the loaded metal compound is zirconium phosphate, and the carrier is D001 macroporous strongly acidic cation exchange resin;

[0050] The lead concentration in the polluted soil was determined to be 57mg / kg, and the remediation rate of the polluted soil can reach 71.5%.

Embodiment 3

[0052] The concentration of lead in heavy metal lead polluted soil is 1000mg / kg;

[0053] Take 3g of the above-mentioned polluted soil and put it into a 100mL beaker, then disperse and bury 0.3g of composite functional resin into the polluted soil, then mix 3mL of ammonium nitrate eluent with a concentration of 0.1mol / L with the polluted soil, and mix the above-mentioned Place the beaker in a horizontal shaker and vibrate for 1 day;

[0054] Wherein, the zirconium loading of the composite functional resin is 10wt%; the loaded metal compound is zirconium phosphate, and the carrier is D001 macroporous strongly acidic cation exchange resin;

[0055] The concentration of lead in the measured soil is 346mg / kg, and the remediation rate of contaminated soil can reach 65.4%.

technical field

[0001] The invention relates to a method for remediating heavy metal-contaminated soil, in particular to a method for in-situ repairing heavy metal-contaminated soil by using a composite functional resin combined with eluent. Background technique

[0002] Soil is the foundation of human survival, and soil pollution will have a very bad impact on human production and life. In recent years, incidents of "blood lead", "cadmium rice" and "arsenic poisoning" have occurred continuously, making the problem of soil heavy metal pollution widely concerned by all walks of life. Generally speaking, the problem of soil pollution in my country is becoming more and more serious. According to statistics, about 300 million mu of arable land in my country is polluted by heavy metals, and 12 million tons of grains are polluted by heavy metals every year. In terms of environmental protection, we must focus on the treatment of polluted soil. Heavy metals in the soil can enter th...

Examples

Embodiment 1

[0042] Preparation of ion exchange resin loaded with zirconium phosphate:

[0043]Take by weighing 20g cation exchange resin D001, the massfraction that it is placed in 100mL is the ZrOCl of 5% (calculated as Zr) 2 The solution was fully stirred at 25°C for 20h. Then, filter out the resin particles and add them to 500mL of phosphoric acid solution with a volume fraction of 20%, and react at 60°C. Drying at lower temperature for 5 hours to obtain a composite functional resin with a zirconium loading of 13 wt%.

[0044] Preparation of ion exchange resin loaded with zirconia:

[0045] Take by weighing 50g cation exchange resin D001, it is placed in the ZrOCl of 5% (in terms of Zr) that it is placed in 200mL mass fraction 2 In the solution, react at a constant temperature of 50°C for 4 hours to fully diffuse the zirconium salt to the inner surface of the resin pores, then filter and place it in 1000mL of 5% sodium hydroxide solution, fully stir and react at room temperature for...

Embodiment 2

[0047] The concentration of lead in heavy metal lead polluted soil is 200mg / kg;

[0048] Take 3g of the above polluted soil and put it into a 100mL beaker, then disperse and bury 0.3g of composite functional resin into the polluted soil, then mix 3mL of ammonium nitrate eluent with a concentration of 0.01mol / L with the polluted soil, and mix the above Place the beaker in a horizontal shaker and vibrate for 1 day;

[0049] Wherein, the zirconium loading of the composite functional resin is 12wt%, the loaded metal compound is zirconium phosphate, and the carrier is D001 macroporous strongly acidic cation exchange resin;

[0050] The lead concentration in the polluted soil was determined to be 57mg / kg, and the remediation rate of the polluted soil can reach 71.5%.

Embodiment 3

[0052] The concentration of lead in heavy metal lead polluted soil is 1000mg / kg;

[0053] Take 3g of the above-mentioned polluted soil and put it into a 100mL beaker, then disperse and bury 0.3g of composite functional resin into the polluted soil, then mix 3mL of ammonium nitrate eluent with a concentration of 0.1mol / L with the polluted soil, and mix the above-mentioned Place the beaker in a horizontal shaker and vibrate for 1 day;

[0054] Wherein, the zirconium loading of the composite functional resin is 10wt%; the loaded metal compound is zirconium phosphate, and the carrier is D001 macroporous strongly acidic cation exchange resin;

[0055] The concentration of lead in the measured soil is 346mg / kg, and the remediation rate of contaminated soil can reach 65.4%.

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