CN110961448A

CN110961448A - Remediation method for organic contaminated soil

Info

Publication number: CN110961448A
Application number: CN201911200552.6A
Authority: CN
Inventors: 饶汀
Original assignee: Individual
Current assignee: Individual
Priority date: 2019-11-29
Filing date: 2019-11-29
Publication date: 2020-04-07

Abstract

The application discloses a remediation method of organic contaminated soil. The method for restoring the organic contaminated soil comprises the following steps: digging out polluted soil, adding water and dilute hydrochloric acid, stirring to make the polluted soil slurried, arranging a plurality of layers of sieve plates in a remediation reactor, attaching a catalyst to each layer of sieve plate, firstly introducing hydrogen into the reactor, wherein the introduction amount of the hydrogen is 500-800 ml/min, replacing the hydrogen with nitrogen after 10-12 hours, then introducing slurry into the reactor, pressurizing, increasing the pressure to 3-3.5 kg, heating the temperature to 250 ℃, introducing the slurry into the reactor to 100-120 ml/min, obtaining treated slurry at the outlet of the reactor, finally adding beneficial microorganisms and organic granular fertilizer into the treated slurry, and filling the slurry back to the original place. The invention creatively adopts a special catalyst to effectively remove aromatic compounds in the soil.

Description

Remediation method for organic contaminated soil

Technical Field

The application relates to the technical field of environmental protection, in particular to a method for repairing organic contaminated soil.

Background

The soil organic pollution mainly comprises chemical pesticide pollution, coking organic pollutant pollution, petroleum organic pollutant pollution and the like. Especially the latter two types of contamination, are the most difficult to handle.

Polycyclic aromatic hydrocarbons are the most common organic pollutants in the soil of coking industrial sites and comprise more than 150 compounds such as naphthalene, anthracene, phenanthrene and pyrene. Polycyclic aromatic hydrocarbons are carcinogenic, teratogenic and mutagenic, and their toxicity increases with the increase of the benzene ring. Among over 500 carcinogenic compounds currently known, over 200 are polycyclic aromatic hydrocarbons and their derivatives. Among them, benzopyrene, anthracene, etc. have strong carcinogenicity. Polycyclic aromatic hydrocarbons are easily adsorbed on soil particles and enter human bodies through digestive tracts, respiratory tracts and skins, thereby inducing skin cancer, lung cancer, rectal cancer, bladder cancer and the like.

After the amount of petroleum substances penetrating into the soil exceeds the self-cleaning capacity of the soil, the accumulated oil substances are remained in the soil for a long time, so that the soil structure is damaged, and the soil permeability is influenced; the fertilizer can adhere to plant roots, hinder the absorption of nutrients and water by the plant roots, cause root rot, influence the growth of crops or penetrate into plant tissues, destroy the normal physiological functions of plants, and seriously influence the productivity of soil and the yield of crops. Benzene, toluene, xylene and other monocyclic aromatic hydrocarbons in petroleum are harmful, acute poisoning mainly acts on human nervous systems, and chronic poisoning mainly acts on hematopoietic tissues and nervous systems. Nausea, headache, dizziness, and the like can also be caused if the particles are exposed to a large concentration of contaminants for a long time.

An effective solution to the problems in the related art has not been proposed yet.

Disclosure of Invention

The purpose of the invention is as follows: since the two main pollutants are monocyclic aromatic hydrocarbon and polycyclic aromatic hydrocarbon, the key point is to remove aromatic compounds. Aiming at the problems in the prior art, the invention provides a remediation method of organic contaminated soil, which is ectopic remediation and can thoroughly remove pollutants by using a specific catalyst to carry out dearomatization reaction.

The technical scheme is as follows: the method for restoring the organic contaminated soil comprises the following steps: digging out polluted soil, adding water and dilute hydrochloric acid, stirring to make the polluted soil slurried, arranging a plurality of layers of sieve plates in a remediation reactor, attaching a catalyst to each layer of sieve plate, firstly introducing hydrogen into the reactor, wherein the introduction amount of the hydrogen is 500-800 ml/min, replacing the hydrogen with nitrogen after 10-12 hours, then introducing slurry into the reactor, pressurizing, increasing the pressure to 3-3.5 kg, heating the temperature to 250 ℃, introducing the slurry into the reactor to 100-120 ml/min, obtaining treated slurry at the outlet of the reactor, finally adding beneficial microorganisms and organic granular fertilizer into the treated slurry, and filling the slurry back to the original place.

Specifically, the active substances of the catalyst are nickel and lanthanum, and the carrier is active alumina; the nickel and the molybdenum exist in an oxidation state. The catalyst comprises 30-35% of nickel, 1-2% of molybdenum and the balance of aluminum oxide.

More specifically, the invention also provides a preparation method of the catalyst, which takes the active alumina ball as a carrier and immerses the active alumina ball into Ni⁺、Mo⁺Soaking the mixture in the solution for 8-10 hours, then drying, roasting at 1200 ℃ for 2-3 hours, and cooling after the roasting is finished to obtain the catalyst. The catalyst is spherical and has a diameter less than 5 mm.

Specifically, the beneficial microorganism mainly contains lactic acid bacteria, yeast and photosynthetic bacteria.

Specifically, the organic granular fertilizer comprises: cellulose, fat, protein, amino acid, hormone, humic acid, and mineral nutrients. The mineral nutrients comprise nitrogen, phosphorus, potassium, sulfur, calcium, magnesium and trace elements.

Specifically, the ratio of the polluted soil, water and dilute hydrochloric acid is 1: 10-20: 0.1-0.2.

Specifically, the ratio of the treated slurry to the organic granular fertilizer is 1: 0.1-0.2.

Has the advantages that: the invention creatively adopts a special catalyst to effectively remove aromatic compounds in the soil.

The organic granular fertilizer used by the invention can provide nutrition for beneficial microorganisms, so that the microorganisms can be propagated in a large quantity, a large quantity of organic acid can be generated in the microbial propagation process, the organic acid can bond soil into a stable granular structure during farming and loosening the soil, the organic acid can also activate solidified phosphorus, potassium and trace elements in the soil to be absorbed and utilized by crops, the microorganisms can decompose organic matters into plant nutrient elements and substances such as cellulose, amino acid, humic acid and the like, and the humic acid has a good effect on improving the soil. .

Detailed Description

In order to make the technical solutions of the present application better understood by those skilled in the art, the technical solutions in the embodiments of the present application will be clearly and completely described below in conjunction with the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, but not all embodiments.

The proportions mentioned in the present example are mass proportions.

Example 1

Catalyst preparation

Using active alumina ball (diameter less than 5mm) as carrier, soaking it in Ni-containing solution⁺、Mo⁺The solution is soaked for 8 hours, then dried, roasted after being dried, the roasting temperature is 1200 ℃, the roasting time is 2 hours, and after the roasting is finished, the solution is cooled, and the catalyst is obtained. The obtained catalyst had a nickel content of 30%, a molybdenum content of 1%, and the balance of alumina.

Example 2

Catalyst preparation

Using active alumina ball (diameter less than 5mm) as carrier, soaking it in Ni-containing solution⁺、Mo⁺The solution is soaked for 10 hours, then dried, roasted after being dried, the roasting temperature is 1200 ℃, the roasting time is 3 hours, and after the roasting is finished, the solution is cooled to obtain the catalyst. The obtained catalyst had a nickel content of 35%, a molybdenum content of 2%, and the balance of alumina.

Example 3

Catalyst preparation

Using active alumina ball (diameter less than 5mm) as carrier, soaking it in Ni-containing solution⁺、Mo⁺The solution is soaked for 10 hours, then dried, roasted after being dried, the roasting temperature is 1200 ℃, the roasting time is 2 hours, and after the roasting is finished, the solution is cooled, and the catalyst is obtained. The catalyst obtained had a nickel content of 32%, a molybdenum content of 2% and the balance of alumina.

Example 4

Testing of catalyst Performance

Benzene is used as a raw material to carry out catalytic reaction. The catalysts of examples 1 to 3, among which the highest conversion rate of example 3, were used in the subsequent repair tests with the catalyst obtained in example 3.

Example 5

Soil remediation treatment (raw material soil with organic matter content of 8% and aromatic compound content of 4%) comprises excavating contaminated soil, adding water and dilute hydrochloric acid (soil, water and dilute hydrochloric acid ratio is 1:10:0.1), stirring to make it slurry, arranging multiple layers of sieve plates in a remediation reactor, attaching catalyst to each layer of sieve plate (example 3), introducing hydrogen into the reactor at 500ml/min, replacing with nitrogen after 10 hr, introducing the slurry into the reactor, pressurizing to increase pressure to 3 kg, heating to 250 deg.C, introducing the slurry at 100ml/min, detecting the treated slurry obtained at the outlet of the reactor, treating soil with organic matter content of less than 0.1% and aromatic compound content of 0, and adding beneficial microorganisms (lactic acid bacteria), Saccharomycete, photosynthetic bacteria) and organic granular fertilizer in the weight ratio of 1 to 0.1, stirring and re-burying in situ.

Example 6

Soil remediation treatment (raw material soil with organic matter content of 8% and aromatic compound content of 4%) comprises excavating contaminated soil, adding water and dilute hydrochloric acid (soil, water and dilute hydrochloric acid ratio of 1:120:0.2), stirring to make slurry, arranging multiple layers of sieve plates in a remediation reactor, attaching catalyst to each layer of sieve plate (example 3), introducing hydrogen into the reactor at a rate of 800ml/min, replacing with nitrogen after 12 hours, introducing the slurry into the reactor, pressurizing to increase pressure to 3.5 kg, heating to 250 deg.C, introducing the slurry at a rate of 120ml/min, collecting the treated slurry at the outlet of the reactor, and finally, detecting that the organic matter content of the treated soil is less than 0.1% and the aromatic compound content is 0, adding beneficial microorganisms (lactic acid bacteria, lactic acid, Saccharomycete, photosynthetic bacteria) and organic granular fertilizer in the weight ratio of 1 to 0.2, stirring and re-burying in situ.

Example 7

Soil remediation treatment (raw material soil with organic matter content of 8% and aromatic compound content of 4%) comprises excavating contaminated soil, adding water and dilute hydrochloric acid (soil, water and dilute hydrochloric acid ratio is 1:20:0.1), stirring to make it slurry, arranging multiple layers of sieve plates in a remediation reactor, attaching catalyst to each layer of sieve plate (example 3), introducing hydrogen into the reactor at a rate of 800ml/min, replacing with nitrogen after 12 hours, introducing the slurry into the reactor, pressurizing to increase pressure to 3 kg, heating to 250 deg.C, introducing the slurry at a rate of 100ml/min, detecting the treated slurry obtained at the outlet of the reactor, treating soil with organic matter content of less than 0.1%, and aromatic compound content of 0, and adding beneficial microorganisms (lactic acid bacteria), Saccharomycete, photosynthetic bacteria) and organic granular fertilizer in the weight ratio of 1 to 0.1, stirring and re-burying in situ.

The above description is only a preferred embodiment of the present application and is not intended to limit the present application.

Claims

1. A method for remediating organically-contaminated soil, comprising: digging out polluted soil, adding water and dilute hydrochloric acid, stirring to make the polluted soil slurried, arranging a plurality of layers of sieve plates in a remediation reactor, attaching a catalyst to each layer of sieve plate, firstly introducing hydrogen into the reactor, wherein the introduction amount of the hydrogen is 500-800 ml/min, replacing the hydrogen with nitrogen after 10-12 hours, then introducing slurry into the reactor, pressurizing, increasing the pressure to 3-3.5 kg, heating the temperature to 250 ℃, introducing the slurry into the reactor to 100-120 ml/min, obtaining treated slurry at the outlet of the reactor, finally adding beneficial microorganisms and organic granular fertilizer into the treated slurry, and filling the slurry back to the original place.

2. The method for remediating organic contaminated soil as recited in claim 1, wherein the active material of the catalyst is nickel or lanthanum, and the carrier is activated alumina; the nickel and the molybdenum exist in an oxidation state.

3. The method for remediating organically-polluted soil as claimed in claim 1, wherein the catalyst comprises 30 to 35% of nickel, 1 to 2% of molybdenum, and the balance of alumina.

4. The method for remediating organic contaminated soil as recited in claim 1, wherein said beneficial microorganisms comprise lactic acid bacteria, yeast, and photosynthetic bacteria.

5. The method for remediating organic contaminated soil as recited in claim 1, wherein said organic granular fertilizer comprises: cellulose, fat, protein, amino acid, hormone, humic acid, and mineral nutrients.

6. The method for remediating organically-polluted soil as claimed in claim 1, wherein the mineral nutrients are nitrogen phosphorus, potassium, sulfur, calcium, magnesium, trace elements.

7. The method for remediating organic contaminated soil as claimed in claim 1, wherein the ratio of contaminated soil, water and diluted hydrochloric acid is 1:10 to 20:0.1 to 0.2.

8. The method for remediating organic contaminated soil according to claim 1, wherein the ratio of the treated slurry to the organic granular fertilizer is 1: 0.1-0.2.