阅读说明：本技术 一种土壤石油烃污染的快速修复装置和修复方法 (Rapid remediation device and remediation method for soil petroleum hydrocarbon pollution ) 是由 席北斗 王雷 李翔 李彤彤 张亚丽 张众磊 牛永超 杨茹月 王杨杨 徐剑锋 于 2020-09-16 设计创作，主要内容包括：本发明公开了一种土壤石油烃的快速修复装置和修复方法,通过采用覆盖地膜的方式提供相对较高的温度,在相对较高温度下,组合使用纳米零价铁体相负载生物炭材料和氧化剂,特别是在联合使用对石油烃具有修复作用的微生物的情况下,能快速对石油烃污染土壤进行修复,去除效率高。(The invention discloses a device and a method for quickly repairing petroleum hydrocarbon in soil, which provide relatively high temperature by adopting a mode of covering a mulching film, load a biochar material and an oxidant by using a nano zero-valent iron body phase at the relatively high temperature in a combined way, and can quickly repair the petroleum hydrocarbon polluted soil particularly under the condition of jointly using microorganisms with the function of repairing the petroleum hydrocarbon, and the removal efficiency is high.)

1. A method for quickly restoring petroleum hydrocarbon in soil features that the nano zero-valent iron phase is used to load biochar and oxidant at relatively high temp (30-70 deg.C).

2. The method for the rapid remediation of soil petroleum hydrocarbons as claimed in claim 1, wherein the relatively high temperature is a temperature of 40-70 ℃, preferably 40-60 ℃.

3. The method for rapidly remediating soil petroleum hydrocarbons as recited in claim 1, wherein the nano zero-valent iron phase-loaded biochar is iron-rich biochar obtained by high-temperature oxygen-free pyrolysis of rice straw planted in acid red soil.

4. The method for the rapid remediation of soil petroleum hydrocarbons as recited in claim 1, wherein the high temperature anaerobic pyrolysis is conducted under a nitrogen atmosphere, comprising:

(1): heating to 400 ℃ at the heating rate of 5-10 ℃/min, and keeping the temperature for 50-80 min;

(2): raising the temperature from 400 ℃ to 600 ℃ and 900 ℃ at the temperature raising rate of 4-8 ℃/min, and preserving the temperature for 30-60 min.

5. The method for the rapid remediation of soil petroleum hydrocarbons as claimed in claim 1, wherein the oxidant is selected from the group consisting of persulfates, chlorine dioxide, ozone, hydrogen peroxide, potassium permanganate, and the like, preferably persulfate.

6. The method for the rapid remediation of soil petroleum hydrocarbons as recited in claim 1, further comprising the remediation by use of a microbial inoculant comprising, preferably consisting of, bacillus subtilis and geobacillus stearothermophilus.

7. The method for rapidly remediating soil petroleum hydrocarbons as claimed in claim 6, wherein the ratio of the number of Bacillus subtilis to the number of Bacillus stearothermophilus is 1-3:1-3, preferably 1-2:2-3, and more preferably 2: 3.

8. The method for rapidly remediating soil petroleum hydrocarbons as recited in claim 1, wherein a crop straw layer is disposed on the petroleum hydrocarbon contaminated soil layer to be remediated, the crop straw layer is formed by stacking crop straws, and the crop straw layer is covered with a mulching film.

9. A device for the rapid remediation of soil petroleum hydrocarbons, the device comprising:

the petroleum hydrocarbon polluted soil layer to be repaired is mixed with nano zero-valent iron phase loaded biochar and an oxidant, and optionally a microbial agent is applied;

a crop straw layer on the petroleum hydrocarbon polluted soil layer to be repaired, wherein the crop straw layer is formed by accumulating crop straws;

and the ground film layer is covered on the crop straw layer.

Technical Field

The invention relates to the technical field of soil remediation, in particular to a quick remediation device and a remediation method for soil petroleum hydrocarbon.

Background

Petroleum is one of our main energy sources, and the problem of petroleum pollution to soil caused by petroleum leakage and discharge in the processes of petroleum extraction, transportation, loading and unloading, storage, processing and use is increasingly highlighted.

The major component of petroleum is petroleum hydrocarbons, i.e., hydrocarbons. The degradation speed of the fertilizer is low in the natural environment of soil, and the fertilizer is accumulated in the soil due to leakage and discharge speed exceeding the degradation speed of the fertilizer, so that plants, animals and even human beings are affected.

Needless to say, soil is the most valuable wealth for humans. The research on the remediation of the soil polluted by petroleum hydrocarbon becomes a hot spot since the 80 th 20 th century. The remediation technology aiming at the petroleum hydrocarbon pollution of soil mainly comprises a physical remediation method such as a heat treatment method, a soil replacement method, an isolation method and the like, a chemical remediation method such as an extraction method, a soil washing method, a chemical oxidation method, a photocatalysis method and the like, a microorganism remediation method such as an in-situ remediation method and an ex-situ remediation method, a plant remediation method and the like.

Microbial remediation is a technology which has been vigorously developed, but the construction, expression and culture costs of engineering strains are expensive.

The chemical oxidation method has high removal efficiency of petroleum hydrocarbon in soil and low cost, but also has the defect of easy damage to soil nutrients.

The research also relates to the use of the biochar to restore the soil polluted by the petroleum hydrocarbon, and the biochar has relatively good restoration effect on the soil polluted by the petroleum hydrocarbon as a widely used green soil conditioner

Disclosure of Invention

The inventor researches and discovers that: the invention is completed by using a nano zero-valent iron body phase loaded biochar material and an oxidant at a relatively high temperature, and particularly under the condition of jointly using microorganisms having a repairing effect on petroleum hydrocarbon, the biochar material can quickly repair the petroleum hydrocarbon polluted soil.

The invention aims to provide a method for quickly repairing petroleum hydrocarbon in soil, which is used for repairing the petroleum hydrocarbon polluted soil by utilizing nano zero-valent iron body phase loaded with biochar and an oxidant at a relatively high temperature, such as a temperature of 30-70 ℃.

The nano zero-valent iron bulk phase loaded biochar is iron-rich biochar, and is preferably obtained by anaerobic high-temperature pyrolysis of iron-rich plants growing in red soil regions.

The oxidant is selected from persulfate, chlorine dioxide, ozone, hydrogen peroxide, potassium permanganate and the like, and persulfate is preferably selected.

The invention also aims to provide a method for quickly restoring petroleum hydrocarbon in soil, which adopts a microbial agent to restore the petroleum hydrocarbon polluted soil under the condition that the petroleum hydrocarbon polluted soil is restored by adopting the combination of nano zero-valent iron body phase loaded biochar and an oxidant at relatively high temperature.

The microbial agent comprises bacillus subtilis and geobacillus stearothermophilus, and preferably consists of bacillus subtilis and geobacillus stearothermophilus.

The invention also aims to provide a method for quickly restoring soil petroleum hydrocarbon, which is characterized in that a crop straw layer is arranged on a petroleum hydrocarbon polluted soil layer to be restored, is formed by stacking crop straws and is covered on the crop straw layer by a mulching film.

It is still another object of the present invention to provide a device for rapidly remediating soil petroleum hydrocarbons, which comprises:

the petroleum hydrocarbon polluted soil layer to be repaired is mixed with nano zero-valent iron phase loaded biochar and an oxidant, and optionally a microbial agent is applied;

a crop straw layer on the petroleum hydrocarbon polluted soil layer to be repaired, wherein the crop straw layer is formed by accumulating crop straws;

and the ground film layer is covered on the crop straw layer.

The rapid soil petroleum hydrocarbon repairing device and the repairing method provided by the invention have the beneficial effects that:

(1) the invention adopts the mode of mulching the mulching film to provide relatively high temperature, is suitable for in-situ repair, is simple and easy to implement and has low cost;

(2) under relatively high temperature, the method is beneficial to the nanometer zero-valent iron phase load biochar material to activate the oxidant, especially persulfate, and synergistically promote the repair and removal of petroleum hydrocarbon;

(3) the method uses the green nano zero-valent iron phase loaded biochar material which has no side effect on the environment, has no secondary pollution to the soil, and has almost no secondary pollution to the soil due to the continuous stable activation of the nano zero-valent iron phase loaded biochar material even if the soil is repaired by combining the oxidizing agent;

(4) the invention also uses microbial inoculum which has no side effect on the environment for repair, further improves the repair effect and effectively promotes the in-situ repair;

(5) the method for restoring the soil polluted by the petroleum hydrocarbon can reduce the content of the petroleum hydrocarbon in the soil to a lower level in a shorter time, and has high removal rate.

Drawings

Fig. 1 shows a schematic structural diagram of a device for rapidly repairing soil petroleum hydrocarbon provided by the invention.

Detailed Description

The present invention will be described in further detail below with reference to preferred embodiments and examples. The features and advantages of the present invention will become more apparent from the description.

The word "exemplary" is used exclusively herein to mean "serving as an example, embodiment, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

The invention provides a method for quickly repairing petroleum hydrocarbon in soil, which uses nano zero-valent iron bulk phase loaded with charcoal and oxidant to repair petroleum hydrocarbon contaminated soil at a relatively high temperature.

The inventor finds that at a relatively high temperature, such as a temperature of 30-70 ℃, preferably a temperature of 40-70 ℃ and a temperature of 40-60 ℃, the nano zero-valent iron body phase loaded biochar and the oxidant can play a better mutual promotion role, and the petroleum hydrocarbon in the polluted soil can be quickly removed with high removal efficiency.

In a preferred embodiment of the present invention, a crop straw layer is disposed on the petroleum hydrocarbon contaminated soil layer to be repaired, the crop straw layer is formed by stacking crop straws, and is covered on the crop straw layer by a mulching film, and small holes can be formed in the mulching film if necessary, so as to provide a relatively high temperature in a desired range to ensure that the petroleum hydrocarbon is carried out at a proper temperature.

The crop straw layer not only helps to provide the desired temperature, but also helps to provide a nutrient source, thereby promoting remediation of soil petroleum hydrocarbons. The thickness is preferably 3 to 10cm, more preferably 4 to 8cm, and still more preferably about 5 cm.

In a preferred embodiment of the invention, the nano zero-valent iron body phase supported on the charcoal is obtained by pyrolyzing iron-rich plants growing in red soil regions at high temperature under anaerobic conditions.

In a more preferred embodiment, the nano zero-valent iron body phase-supported biochar is prepared by a method comprising the following steps:

(1) cultivating/planting iron-rich plants

Wherein, the iron-rich plant is preferably selected from one or more of rice, ramie, iris and canna. More preferably, the iron-rich plant is rice.

In order to enrich the iron, the cultivation period of the iron-rich plants is as long as possible, such as more than 3 months, and nutrient solution for promoting the absorption of iron, such as dilute citric acid solution and the like, such as dilute citric acid solution with the concentration of 100mg/L, 200mg/L, 300mg/L, 400mg/L, 500mg/L and the like, can be applied.

(2) Pyrolyzing iron-rich plants

In one embodiment, the iron-rich plants are harvested, washed with deionized water, soaked in dilute hydrochloric acid, air dried, chopped, dried, and pyrolyzed.

In a preferred embodiment according to the invention, the pyrolysis is carried out in a muffle furnace. Under oxygen exclusion conditions, such as under a nitrogen purge, the following is performed:

(1): heating to 400 ℃ at a heating rate of 5-10 ℃/min, preferably 5-8 ℃/min, and keeping the temperature for 50-80 min, preferably 50-60 min;

(2): the temperature is raised from 400 ℃ to 600-900 ℃, preferably 650-850 ℃, more preferably 700-800 ℃ at a temperature raising rate of 4-8 ℃/min, preferably 4-6 ℃/min, and the temperature is maintained for 30-60 min, preferably 30-50 min, more preferably 30-40 min.

The inventor researches and discovers that the nano zero-valent iron phase loaded biochar prepared under the conditions has a higher specific surface area, has more stable and durable repair capability and is beneficial to improving the efficiency of repairing petroleum hydrocarbon polluted soil.

The nano zero-valent iron phase loaded biochar material used as the iron-rich biomass is a green repair material, and does not cause secondary pollution to soil. In addition, the surface area of the soil remediation agent is higher than that of the surface of the nano zero-valent iron loaded with the biochar, the soil remediation agent is better, more stable and more durable, and the removal rate of petroleum hydrocarbon in the soil are obviously improved.

The inventor researches and discovers that when the composite material with the nano zero-valent iron uniformly loaded in the biochar phase and the oxidant are used in combination to repair the petroleum hydrocarbon polluted soil, a better repairing effect can be achieved, and the removing speed and the removing rate of the petroleum hydrocarbon are higher.

In a further preferred embodiment, the oxidizing agent is selected from persulfates, chlorine dioxide, ozone, hydrogen peroxide, potassium permanganate, and the like, preferably persulfates.

The inventor finds that the composite material in which the nanometer zero-valent iron is uniformly loaded in the biochar phase can effectively activate the oxidant, particularly the persulfate, so as to rapidly and efficiently remove the petroleum hydrocarbon when repairing the soil polluted by the petroleum hydrocarbon.

In a further preferred embodiment, the dosage ratio of the biochar loaded by the nano zero-valent iron body phase to the oxidant is 100 parts by weight: 10-30 parts by weight, preferably 100 parts by weight: 10-20 parts by weight, more preferably 100 parts by weight: 10 parts by weight.

When the dosage is used, good remediation effect on the petroleum hydrocarbon polluted soil can be realized, and little or minimum adverse effect on the soil can be realized.

The inventor researches and discovers that when the petroleum hydrocarbon polluted soil is repaired, in the case of repairing the petroleum hydrocarbon polluted soil by using the nanometer zero-valent iron body phase loaded on the charcoal material and the oxidant such as persulfate, such as potassium persulfate or sodium persulfate, in combination, the soil can also be repaired by using the microbial agent, so that the repairing effect is further improved.

In particular, after the petroleum hydrocarbon polluted soil is repaired by using the nano zero-valent iron phase loaded with the biochar material and the oxidant, the soil is repaired by using the microbial inoculum for more than 3 days, preferably more than 7 days, and more preferably more than 10 days.

In a preferred embodiment of the invention, the microbial agent comprises, preferably consists of, bacillus subtilis and geobacillus stearothermophilus.

In a more preferred embodiment of the invention, the ratio of the number of Bacillus subtilis to the number of Bacillus stearothermophilus is 1-3:1-3, preferably 1-2:2-3, more preferably 2: 3. In this case, remediation of soil petroleum hydrocarbons can be advantageously facilitated.

The bacillus subtilis and the bacillus stearothermophilus may be applied in the form of a bacterial solution or a bacterial powder, but preferably in the form of a bacterial solution.

In a further preferred embodiment, the number of active bacteria in the bacterial liquid is not less than 1.0X 10⁷cfu/mL, preferably not less than 2.0X 10⁷cfu/mL, more preferably not less than 5.0X 10⁷cfu/mL。

In order to implement the remediation method, the invention also provides a rapid remediation device for soil petroleum hydrocarbons, which comprises:

the petroleum hydrocarbon polluted soil layer 1 to be repaired is mixed with nano zero-valent iron phase loaded biochar and an oxidant, and optionally a microbial agent is applied;

the crop straw layer 2 is arranged on the petroleum hydrocarbon polluted soil layer to be repaired, and is formed by accumulating crop straws;

and the ground film layer 3 is covered on the crop straw layer.

Examples

The present invention is further described below by way of specific examples, which are merely exemplary and do not limit the scope of the present invention in any way.

Example 1

The petroleum hydrocarbon polluted soil is obtained from the third oil production plant of the Tianjin Hongkong oil field. And (4) drying and crushing the collected polluted soil sample. Sampling and testing, wherein the total petroleum hydrocarbon content is 5092mg/kg, and sterilizing and drying the rest parts to obtain a soil sample to be repaired.

The rice is planted in the red soil for 100 days, and 300mg/L citric acid aqueous solution is sprayed every week. After 100 days, the rice is pulled out, the paddy is removed, the rice straw is left, the rice straw is cleaned by deionized water, the rice straw is soaked in 0.01M dilute hydrochloric acid for 1 hour, the rice straw is dried and chopped, the rice straw is divided into two parts of root and straw, the root and the straw are respectively dried at the temperature of 70.0 ℃, and the straw is crushed into particles with the diameter of 1 mm. Under the nitrogen purging, the temperature is raised to 400 ℃ at the temperature raising rate of 6 ℃/min, the temperature is preserved for 50 min, and then the temperature is raised from 400 ℃ at the temperature raising rate of 4 ℃/minThe temperature is increased to 700 ℃, the temperature is preserved for 40 minutes, and the nano zero-valent iron body phase load biological carbon with the specific surface area of 211.7m is obtained²/g。

And (2) taking a part of soil sample to be repaired, transferring the part of soil sample to be repaired into a flowerpot, mixing nano zero-valent iron phase loaded biochar in an amount of 20g/kg of soil, then spraying 0.1g/L potassium persulfate solution in an amount of 5g/kg of soil, placing the mixture into a thermostat at the temperature of 50 ℃, watering every other day, and keeping the soil moist. After 7 days, a sample was taken and tested, and the total petroleum hydrocarbon content was 2282 mg/kg.

Example 2

The rice is planted in the red soil for 100 days, and 100mg/L citric acid aqueous solution is sprayed every week. After 100 days, the rice is pulled out, the paddy is removed, the rice straw is left, the rice straw is cleaned by deionized water, the rice straw is soaked in 0.01M dilute hydrochloric acid for 1 hour, the rice straw is dried and chopped, the rice straw is divided into two parts of root and straw, the root and the straw are respectively dried at the temperature of 70.0 ℃, and the straw is crushed into particles with the diameter of 1 mm. Under the nitrogen purging, the temperature is raised to 400 ℃ at the temperature raising rate of 5 ℃/min, the temperature is preserved for 50 min, then the temperature is raised to 780 ℃ from 400 ℃ at the temperature raising rate of 6 ℃/min, the temperature is preserved for 35 min, and the nano zero-valent iron body phase loaded biochar with the specific surface area of 211.3m is obtained²/g。

A part of the soil sample to be repaired in example 1 is taken and transferred into a flowerpot, iron-rich biochar is mixed according to the amount of 20g/kg of soil, the soil sample is placed in a thermostat at 50 ℃, watering is carried out every other day, and the soil is kept moist.

After 10 days, a microbial composite inoculum consisting of 1.0X 10 was added thereto⁸cfu/mL Bacillus subtilis and 1.0X 10⁸The mixture of cfu/mL Geobacillus stearothermophilus (Shanghai brand name: Hill Biotech Co., Ltd.) in a volume ratio of 2:3 was added in an amount of 50mL/kg soil.

After 15 days, a sample was taken and tested to determine the total petroleum hydrocarbon content of 1451 mg/kg.

Example 3

The rice is planted in the red soil for 100 days, and 100mg/L citric acid aqueous solution is sprayed every week. After 100 days, the rice is pulled out, the paddy is removed, the rice straw is left, the rice straw is cleaned by deionized water, the rice straw is soaked in 0.01M dilute hydrochloric acid for 1 hour, the rice straw is dried and cut up, the straw is divided into two parts of root and straw, and the two parts are respectively placed in the root and strawOven drying at 70.0 deg.C, and pulverizing into 1mm granule. Under the nitrogen purging, the temperature is raised to 400 ℃ at the temperature raising rate of 5 ℃/min, the temperature is preserved for 50 min, then the temperature is raised to 780 ℃ from 400 ℃ at the temperature raising rate of 6 ℃/min, the temperature is preserved for 35 min, and the nano zero-valent iron body phase loaded biochar with the specific surface area of 211.3m is obtained²/g。

A part of the soil sample to be repaired in example 1 is taken and transferred into a flowerpot, iron-rich biochar is mixed according to the amount of 20g/kg of soil, the soil sample is placed in a thermostat at 50 ℃, watering is carried out every other day, and the soil is kept moist.

After 10 days, a microbial composite inoculum consisting of 1.0X 10 was added thereto⁸cfu/mL Bacillus subtilis and 1.0X 10⁸The mixture of cfu/mL Geobacillus stearothermophilus (Shanghai brand name: Hill Biotech Co., Ltd.) in a volume ratio of 2:3 was added in an amount of 50mL/kg soil.

Then weaving a wheat straw layer with the thickness of about 5cm on the flowerpot soil by using dry wheat straws, sealing the wheat straw layer by using a mulching film, placing the wheat straw layer in a thermostat at 50 ℃, opening the mulching film every other day, watering, and keeping the wheat straw layer moist.

After 60 days, sampling and testing, wherein the total petroleum hydrocarbon content is 363 mg/kg.

The invention has been described in detail with reference to specific embodiments and illustrative examples, but the description is not intended to be construed in a limiting sense. Those skilled in the art will appreciate that various equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its embodiments without departing from the spirit and scope of the present invention, which fall within the scope of the present invention.