A device and method for in-situ remediation of organic contaminated soil

Abstract

The application relates to the technical field of soil remediation, in particular to a device for in-situ remediation of organic contaminated soil, which comprises a power supply, a high-pressure pump, an air extractor and a buried unit, the buried unit comprises a plurality of buried groups which are spaced apart along a first direction alpha, and each buried group comprises a plurality of buried pieces which are spaced apart along a second direction beta; the buried pieces are made of iron and are used for generating ferrous ions to activate persulfate and generate iron ions after the activation reaction; the buried pieces comprise liquid inlet buried pieces and suction buried pieces, the cavities of the liquid inlet buried pieces are communicated with the output end of the high-pressure pump, the high-pressure pump is used for pumping sodium persulfate solution into the cavities of the liquid inlet buried pieces, the cavities of the suction buried pieces are communicated with the input end of the air extractor, and the air extractor is used for sucking water in the soil; the sodium persulfate solution is activated by adopting direct current and an iron-based catalyst, and the organic pollutants in the soil can be effectively degraded.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of soil remediation, in particular to a device for in-situ remediation of organic contaminated soil. BACKGROUND

[0002] Soil pollution caused by polycyclic aromatic hydrocarbons (PAHs), phenolic compounds, herbicides, antibiotics is a serious environmental problem. The presence of organic pollutants can affect the normal function of the soil, thus affecting human health and environmental quality, as they are non-biodegradable, extremely toxic, and very strongly bioaccumulating.

[0003] In-situ soil remediation refers to a soil remediation technology that does not move the contaminated soil, but directly repairs or treats the contaminated site at the location where the pollution occurs. It has the characteristics of low investment and small impact on the surrounding environment. Persulfate activation is a highly concerned advanced oxidation technology in the field of water purification and pollutant removal in recent years. Persulfate can be effectively transported to specific pollution areas due to its relatively high redox potential and chemical stability.

[0004] Persulfate has certain difficulties in application to soil remediation, namely activation and dispersion. Persulfate must be activated to obtain better oxidation effect. In addition to activation, it is also difficult for persulfate to disperse into soil. SUMMARY

[0005] The technical problem to be solved by the present application is to overcome the problems of activation and dispersion of persulfate in the process of applying persulfate to soil remediation in the prior art. Persulfate must be activated to obtain better oxidation effect. In addition to activation, it is also difficult for persulfate to disperse into soil. The present application provides a device for in-situ remediation of organic contaminated soil.

[0006] The technical solution adopted by the present application to solve the technical problem is: a device for in-situ remediation of organic contaminated soil, comprising a power supply, a high-pressure pump, an air extractor and a buried unit,

[0007] The buried unit comprises a plurality of buried groups spaced apart along a first direction alpha, and each buried group comprises a plurality of buried pieces spaced apart along a second direction beta, the first direction alpha and the second direction beta are staggered, a part of the buried groups are connected to a first electrode of the power supply, another part of the buried groups are connected to a second electrode of the power supply, and the polarity of the first electrode of the power supply is opposite to the polarity of the second electrode of the power supply;

[0008] The buried piece is made of iron and is used to generate ferrous ions to activate persulfate and generate iron ions after activation reaction. The buried piece has a cavity inside, a plurality of through holes for fluid inflow or outflow are formed on the side wall of the buried piece, and the through holes are in communication with the cavity.

[0009] The buried part includes a liquid inlet buried part and a suction buried part, the cavity of the liquid inlet buried part is communicated with the output end of a high-pressure pump, the high-pressure pump is used for pumping sodium persulfate solution into the cavity of the liquid inlet buried part, the cavity of the suction buried part is communicated with the input end of an air extractor, the air extractor is used for sucking water in the soil, and the sodium persulfate solution is activated by using direct current and an iron-based catalyst, so that the organic pollutants in the soil can be effectively degraded.

[0010] In order to solve the problems of single buried part, serious loss and small treatment range, the device for in-situ remediation of organic contaminated soil further comprises a positive-negative converter, the first electrode and the second electrode of the power supply are connected to the positive-negative converter, the first electrode of the positive-negative converter is connected to one part of the buried groups, the second electrode of the positive-negative converter is connected to another part of the buried groups, the polarity of the first electrode of the positive-negative converter is opposite to the polarity of the second electrode of the positive-negative converter, and the positive-negative converter can switch the polarity of the first electrode and the second electrode thereof.

[0011] Further, the electrode polarities of the power supplies connected to the adjacent two buried groups are opposite.

[0012] In order to solve the problem that the liquid inlet buried part and the suction buried part are far apart and difficult to cooperate, the liquid inlet buried part and the suction buried part in each group are staggered.

[0013] In order to solve the problem that the liquid inlet buried part and the suction buried part are far apart and difficult to cooperate, the liquid inlet buried part and the suction buried part arranged along the first direction α are staggered.

[0014] In order to solve the problem that the buried part is inconvenient to insert into the soil, the bottom end of the buried part is a conical structure.

[0015] In order to solve the problem that the water sucked into the soil is too much and there is no storage place, the device for in-situ remediation of organic contaminated soil further comprises a storage barrel, the storage barrel is arranged between the suction buried part and the air extractor, the input end of the storage barrel is communicated with the suction buried part, and the output end of the storage barrel is communicated with the input end of the air extractor.

[0016] Further, the installation interval of the adjacent two buried parts is 40-100 cm.

[0017] In order to solve the problem of how to treat soil pollution, a remediation method of a device for in-situ remediation of organic contaminated soil is further included, which comprises the following steps:

[0018] S1: inserting the buried parts into the soil at intervals of 40-100 cm;

[0019] S2: turn on the power supply, so that the ground buried with the positive pole of the power supply produces ferrous ions, and the ground buried on the row is connected to the positive and negative pole converter every 12h to switch the positive and negative poles of the power supply;

[0020] S3: the high-pressure pump pumps the sodium persulfate solution into the liquid inlet ground buried and flows out to the soil through the through hole of the liquid inlet ground buried, the sodium persulfate solution and the ferrous ions contact to produce activation, and then oxidize and degrade the contacted organic matter;

[0021] S4: the suction ground buried is connected with the air extractor, and the air extractor absorbs water into the storage barrel.

[0022] The device for repairing organic contaminated soil in situ provided by the application has the advantages that:

[0023] 1. The direct current and the iron-based catalyst are used to activate the sodium persulfate solution, and the organic pollutants in the soil can be effectively degraded;

[0024] 2. The electrochemical corrosion is used to form Fe 2 +, Fe 2 +, which activates the persulfate and is converted into Fe 3 +, Fe 3 + and soil organic matter complex, and is reduced to Fe 2 + under the action of the electric field, thereby reducing the material consumption and continuously activating the persulfate and degrading the pollutants;

[0025] 3. The advanced oxidation method is conveniently applied to soil remediation, is more convenient than ex situ remediation, and is easier to operate than traditional in situ remediation. BRIEF DESCRIPTION OF DRAWINGS

[0026] The application will be further described below in combination with the drawings and examples.

[0027] Figure 1 is a structural schematic diagram of the application;

[0028] Figure 2 is a sectional structural schematic diagram of the ground buried of the application.

[0029] In the figure: 1, power supply, 2, high-pressure pump, 3, air extractor, 4, ground buried, 4a, liquid inlet ground buried, 4b, suction ground buried, 41, cavity, 42, through hole, 5, storage barrel, 6, positive and negative pole converter. DETAILED DESCRIPTION

[0030] The application will be further described below in combination with the drawings and examples.

[0031] AsFigure 1 is a structural diagram of the application, an in-situ remediation device for organic contaminated soil, comprising a power supply 1, a high-pressure pump 2, an air extractor 3 and a buried unit,

[0032] The buried unit comprises a plurality of buried groups spaced along a first direction a, and the buried group comprises a plurality of buried pieces 4 spaced along a second direction β, and the first direction a and the second direction β are staggered, wherein a part of the buried groups are connected to the first electrode of the power supply 1, and another part of the buried groups are connected to the second electrode of the power supply 1, and the polarity of the first electrode of the power supply 1 is opposite to the polarity of the second electrode of the power supply 1, and the first electrode of the power supply 1 is its positive electrode, and the first electrode of the power supply 1 is its negative electrode, and the application does not make specific limitations, and the power supply 1 is a direct current power supply, and the voltage of the power supply 1 is 30-40V;

[0033] The in-situ remediation device for organic contaminated soil further comprises a positive and negative electrode converter 6, and the first electrode and the second electrode of the power supply 1 are connected to the positive and negative electrode converter 6, and the first electrode of the positive and negative electrode converter 6 is connected to a part of the buried groups, and the second motor of the positive and negative electrode converter 6 is connected to another part of the buried groups, and the polarity of the first electrode of the positive and negative electrode converter 6 is opposite to the polarity of the second electrode of the positive and negative electrode converter 6, and the positive and negative electrode converter 6 can switch the polarity of its first electrode and the polarity of its second electrode, which can ensure the activity of the iron anode and cathode, so that the anode and cathode can play their roles, because the anode material is consumed, and after switching, the two electrodes can be evenly consumed; switching the electrode can also alleviate the influence of uneven electric field distribution in the process of electron transfer on the degradation effect of organic matter in the soil.

[0034] The polarity of the electrodes of the power supply 1 connected by adjacent two buried groups is opposite, and the positive and negative electrodes of the power supply 1 of adjacent buried groups are opposite, in order to form a potential difference around each electrode, to facilitate electron transfer, so as to promote the conversion of ferrous ions and iron ions, and activate persulfate to degrade organic matter in the soil.

[0035] As shown in Figure 2 The buried piece is made of iron, and the buried piece 4 is used to generate ferrous ions to activate persulfate after being electrified and generate iron ions after the activation reaction, and the buried piece 4 has a cavity 41 inside, and a plurality of through holes 42 for fluid inflow or outflow are formed on the side wall of the buried piece, and the through holes 42 and the cavity 41 are communicated, and the bottom end of the buried piece 4 is a conical structure, which is convenient for inserting into the soil;

[0036] The installation spacing of adjacent two buried pieces 4 is 40-100cm, so that the buried pieces 4 are arranged dispersedly, the repair area is expanded, and the overlap rate of adjacent buried pieces 4 for repairing soil is avoided;

[0037] The buried part 4 includes a liquid inlet buried part 4a and a suction buried part 4b, the cavity 41 of the liquid inlet buried part 4a is communicated with the output end of the high-pressure pump 2, the high-pressure pump 2 can also be a pump such as a water pump, and the present application does not make specific limitation, the high-pressure pump 2 is used for pumping sodium persulfate solution into the cavity 41 of the liquid inlet buried part 4a, the buried part 4 is connected with the output end of the high-pressure pump 2 through a hose

[0038] The cavity 41 of the suction buried part 4b is communicated with the input end of the air extractor 3, the air extractor 3 is used for sucking water in the soil, the air extractor 3 can also be a negative pressure pump or a vacuum pump, and the present application does not make specific limitation.

[0039] The liquid inlet buried part 4a and the suction buried part 4b in each group are staggered, the liquid inlet buried part 4a and the suction buried part 4b distributed in the first direction α are staggered, that is, the adjacent buried parts 4 in front of and behind and left and right of the liquid inlet buried part 4a are the suction buried parts 4b or the adjacent buried parts 4 in front of and behind and left and right of the suction buried part 4b are the liquid inlet buried parts 4a, the staggered arrangement is more uniform than the single spaced arrangement, which facilitates uniform delivery of sodium persulfate solution to the contaminated soil; the staggered arrangement of the buried parts 4 connected with the air extractor 3 also facilitates the suction of the treated water.

[0040] The device for in-situ remediation of organic contaminated soil also includes a storage barrel 5, the storage barrel 5 is arranged between the suction buried part 4b and the air extractor 3, the input end of the storage barrel 5 is communicated with the suction buried part 4b, the storage barrel 5 and the suction buried part 4b are connected through a hose, the output end of the storage barrel 5 is communicated with the input end of the air extractor 3, the storage barrel 5 and the air extractor 3 are connected through a hose, the storage barrel 5 can store the water extracted from the underground and the water can be used to configure sodium persulfate solution.

[0041] A remediation method using the device for in-situ remediation of organic contaminated soil, comprising the following steps:

[0042] S1: inserting the buried part 4 into the soil at intervals of 40-100 cm, the buried part 4 is arranged with five rows in the present application, and each row has five buried parts;

[0043] S2: connecting the power supply 1 to form an electric field between each group of buried parts 4, and under the action of the electric field, the anode (i.e. the buried part 4 connected with the positive pole of the power supply 1) is self-corrosive, so that the buried part 4 connected with the positive pole of the power supply 1 generates ferrous ions, and the buried parts 4 on one row are switched once every 12 h through the positive and negative pole converter 6 to switch the positive and negative poles of the power supply 1 connected;

[0044] S3: The high-pressure pump 2 pumps the sodium persulfate solution into the liquid inlet underground part 4a and flows out to the soil through the through hole 41 of the liquid inlet underground part 4a, the mass concentration of the sodium persulfate solution is 5%-10%, the sodium persulfate solution and the ferrous ion contact to produce the activation effect, and then the oxidation degradation with the contacted organic matter occurs, when the sodium persulfate solution flows out from the underground part to the soil, the sodium persulfate and the ferrous ion contact to produce the activation effect, and the oxidation degradation with the contacted organic matter occurs;

[0045] S4: The suction underground part 4b is connected with the air extractor 3, the air extractor 3 sucks the water into the storage barrel 5 through the through hole 42 of the suction underground part 4b, the ferrous ion produced by the sodium persulfate and the underground part 4 continuously produces the activation effect and produces the iron ion, and the organic matter in the hose pipeline and the storage cavity of the storage barrel 5 continuously oxidizes; the sucked water can be reused to prepare the sodium persulfate solution, and the produced iron ion can produce the complexation with the organic acid in the soil and remain in the soil, under the action of the electric field, the iron ion combines with the electron and can be reduced to the ferrous ion again to continuously participate in the activation process, and the whole process does not produce waste.

[0046] The water sucked by the air extractor 3 can include the ferrous ion, the sodium persulfate and the residual organic pollutants, and the pollutants are transferred from the soil to the water, which is more convenient to handle and is also a method for removing the pollutants in the soil, the sucked water can be treated and then used to prepare the sodium persulfate solution; the air extractor 3 can select the motors with different powers according to the water amount and the depth of the soil; the working principle of the water pump is to use the rotating force of the motor to bring the water in the water pump out to achieve the purpose of pumping water, and the vacuum or negative pressure can be continuously formed at the inlet during the pumping process; the water sucked by the air extractor is stored in the storage barrel 5, and the water in the barrel is emptied in time.

[0047] Based on the above ideal embodiments according to the present application, through the above description, relevant personnel can make various changes and modifications without deviating from the technical idea of the present application. The technical scope of the present application is not limited to the contents in the specification, and the technical scope must be determined according to the scope of claims.

Claims

1. An apparatus for in situ remediation of organic contaminated soil, characterized by, The device comprises a power supply (1), a high-pressure pump (2), an air extractor (3) and a buried unit, The buried unit comprises a plurality of buried groups spaced apart along a first direction α, each buried group comprises a plurality of buried members (4) spaced apart along a second direction β, the first direction α and the second direction β are staggered, wherein a part of the buried groups are connected to a first electrode of the power supply (1), and another part of the buried groups are connected to a second electrode of the power supply (1), the first electrode of the power supply (1) and the second electrode of the power supply (1) are opposite in polarity, the liquid inlet buried members (4a) and the suction buried members (4b) in each group are staggered, and the liquid inlet buried members (4a) and the suction buried members (4b) spaced apart along the first direction α are staggered. The buried member (4) is made of iron, which is used to activate persulfate by generating ferrous ions after being electrified, and generate iron ions after activation reaction, which can be reduced to ferrous ions under the action of electric field by complexing with soil organic matter, the buried member (4) has a cavity (41) inside, and a plurality of through holes (42) for fluid inflow or outflow are formed on the side wall of the buried member, the through holes (42) and the cavity (41) are communicated. The buried member (4) comprises a liquid inlet buried member (4a) and a suction buried member (4b), the cavity (41) of the liquid inlet buried member (4a) is communicated with the output end of the high-pressure pump (2), the high-pressure pump (2) is used for pumping sodium persulfate solution into the cavity (41) of the liquid inlet buried member (4a), and the cavity (41) of the suction buried member (4b) is communicated with the input end of the air extractor (3), the air extractor (3) is used for sucking water in the soil to assist in removing pollutants.

2. An apparatus for in situ remediation of organic contaminated soil as claimed in claim 1 wherein: The device for in-situ remediation of organic contaminated soil further comprises a positive and negative electrode converter (6), the first electrode and the second electrode of the power supply (1) are connected to the positive and negative electrode converter (6), the first electrode of the positive and negative electrode converter (6) is connected to a part of the buried groups, the second electrode of the positive and negative electrode converter (6) is connected to another part of the buried groups, the first electrode of the positive and negative electrode converter (6) and the second electrode of the positive and negative electrode converter (6) are opposite in polarity, and the positive and negative electrode converter (6) can switch the polarity of the first electrode and the second electrode.

3. An apparatus for in situ remediation of organic contaminated soil as claimed in claim 1 or 2, wherein: The electrode polarity of the power supply (1) connected by adjacent two buried groups is opposite.

4. An apparatus for in situ remediation of organic contaminated soil as claimed in claim 1 wherein: The bottom end of the buried member (4) is in a conical structure.

5. An apparatus for in situ remediation of organic contaminated soil as claimed in claim 1 wherein: The device for in-situ remediation of organic contaminated soil further comprises a storage barrel (5), the storage barrel (5) is arranged between the suction buried member (4b) and the air extractor (3), the input end of the storage barrel (5) is communicated with the suction buried member (4b), and the output end of the storage barrel (5) is communicated with the input end of the air extractor (3).

6. An apparatus for in situ remediation of organic contaminated soil as claimed in claim 1 wherein: The installation interval of adjacent two buried members (4) is 40-100 cm.

7. A remediation method of in situ remediation of organic contaminated soil using the apparatus according to any one of claims 1 to 6, characterized in that, The device comprises the following steps: S1: inserting the buried members (4) into the soil at intervals of 40-100 cm; S2: turn on the power supply (1), so that the ground buried part (4) connected with the positive pole of the power supply (1) produces ferrous ions, and the ground buried part (4) on the row is switched every 12h by the positive and negative pole converter (6) The positive and negative poles of the power supply (1) connected; S3: the high-pressure pump (2) pumps the sodium persulfate solution into the liquid inlet ground buried part (4a) and flows out to the soil through the through hole (41) of the liquid inlet ground buried part (4a), the sodium persulfate solution and ferrous ions contact to produce activation, and then oxidize and degrade the contacted organic matter; S4: the suction ground buried part (4b) is connected with the air extractor (3), and the air extractor (3) absorbs water into the water storage barrel (5).

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