Double adsorption structure of electrode plate carbon felt adsorption layer of PRB magnetic bioactive carbon permeable wall and application thereof

Abstract

The application discloses a PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure and application, and relates to an electrode plate carbon felt adsorption layer double adsorption structure and application. The application is aimed at solving the problems of limited soil quantity for processing each time and high cost of existing soil heavy metal removal methods, and the structure of the application comprises a first polyethylene net fixed layer, an activated carbon zero-valent iron reduction layer, a magnetic biochar adsorption layer and a second polyethylene net fixed layer, wherein one side of the second polyethylene net fixed layer is connected with the magnetic biochar adsorption layer, and the other side is connected with the electrode plate surface carbon felt adsorption layer. The application is applied to an electrolyte circulation technology reinforced electromotive force soil heavy metal removal device. The application has the characteristics of no secondary pollution and simple operation, has good removal efficiency for heavy metals and organic pollutants in low-permeability and multi-phase inhomogeneous soil media, and has low overall cost. The application belongs to the field of soil heavy metal remediation.

Description

TECHNICAL FIELD

[0001] The application relates to a double adsorption structure of an electrode plate carbon felt adsorption layer and application thereof. BACKGROUND

[0002] Due to the characteristics of heavy metals such as difficult degradation and strong stability, microorganisms cannot degrade the heavy metals, which poses a great threat to the soil ecosystem. When the heavy metals in the soil environment accumulate to a certain degree, they are absorbed by crops to produce cumulative effects or generate compounds with greater toxicity, which can cause human beings to suffer from skin cancer, adenocarcinoma, neuritis and other related diseases. Therefore, from the perspective of protecting the health of the public, it is of great significance to study the remediation of heavy metals in soil.

[0003] The removal technologies of soil heavy metals mainly include: electrokinetic removal technology, chemical method, biological leaching method, etc. The electrokinetic removal technology has high heavy metal removal rate and short treatment time, but the technology consumes a large amount of electric energy, and the amount of soil treated at a time is limited. In general, the technology is combined with other treatment technologies to improve the heavy metal removal efficiency, which increases the cost, and therefore the application of the method is limited. The chemical method is to extract the heavy metals in the soil into a solution by using various acids or complexing agents, and then to perform solid-liquid separation. The heavy metals in the solution are further treated. The chemical method has good effect on the treatment of heavy metals in soil. Since the soil needs to be acidified, a large amount of reagent is required. Meanwhile, the acid solution after treatment also needs to be neutralized, which requires high corrosion resistance of the equipment, and the cost of the reagent and the equipment is relatively large. The biological leaching technology uses microorganisms to produce an acid condition, and under the acid condition, the heavy metals in the soil are released into the solution, and then the soil and water are separated to achieve the purpose of removing the heavy metals in the soil. The commonly used microorganisms in the biological leaching method are sulfur-oxidizing Thiobacillus and iron-oxidizing Thiobacillus, etc. The acid consumption in the biological leaching process is small, and the loss of nitrogen and phosphorus elements is small. Since the pH in the leaching process is reduced to about 2, the subsequent heavy metal waste liquid treatment is difficult, and the cost is also increased. SUMMARY

[0004] The application aims to solve the technical problems of the existing soil heavy metal removal method that the amount of soil treated at a time is limited and the cost is relatively large, and provides a PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure and application thereof.

[0005] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure comprises a PRB magnetic bioactive carbon permeable wall and an electrode plate surface carbon felt adsorption layer, the PRB magnetic bioactive carbon permeable wall is sequentially composed of a first polyethylene net fixed layer (with an optimal pore diameter of 1 mm to ensure maximum contact area while preventing filler leakage), an activated carbon zero-valent iron reduction layer, a magnetic bioactive carbon adsorption layer and a second polyethylene net fixed layer, one side of the second polyethylene net fixed layer (with an optimal pore diameter of 1 mm to ensure maximum contact area while preventing filler leakage) is connected with the magnetic bioactive carbon adsorption layer, and the other side is connected with the electrode plate surface carbon felt adsorption layer.

[0006] The activated carbon zero-valent iron reduction layer filler is zero-valent iron scrap.

[0007] The magnetic bioactive carbon adsorption layer filler is magnetic bioactive carbon granular material.

[0008] The pore diameter of the first polyethylene net fixed layer is 1 mm.

[0009] The pore diameter of the second polyethylene net fixed layer is 1 mm.

[0010] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is applied to an electrolyte circulation reinforced electrokinetic technology soil heavy metal remediation device, one PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is arranged on one side of an electrode plate of the electrolyte circulation reinforced electrokinetic technology soil heavy metal remediation device close to a soil remediation chamber, the electrode plate surface carbon felt adsorption layer is made of a layer of carbon felt adsorption layer uniformly laid on the electrode plate, and the electrode plate surface carbon felt adsorption layer is connected with one side of the second polyethylene net fixed layer.

[0011] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is applied to an electrolyte circulation reinforced electrokinetic technology soil heavy metal remediation device, one PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is arranged on one side of an electrode plate of the electrolyte circulation reinforced electrokinetic technology soil heavy metal remediation device close to a soil remediation chamber, in the migration process of metal ions, the metal ions are subjected to one adsorption by the PRB magnetic bioactive carbon permeable wall, and the migrated heavy metal pollutants are subjected to two adsorptions by the electrode plate surface carbon felt adsorption layer, and the double adsorption process is completed by the two structures.

[0012] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is used on an electrolyte circulation reinforced electrokinetic technology soil heavy metal remediation device for the first time.

[0013] The first layer of the PRB magnetic biochar permeable wall is zero-valent iron, which can reduce the reducible heavy metal pollutants to metal elements on the surface of the zero-valent iron layer based on the free charge generated by electrolysis.

[0014] The second layer of the PRB magnetic biochar permeable wall is magnetic biochar granular material, which can firmly adsorb the heavy metal pollutants when the heavy metal pollutants reach the magnetic biochar layer.

[0015] The second adsorption structure is a carbon felt adsorption layer uniformly distributed on the electrode plate, which can perform secondary adsorption on a small amount of heavy metal pollutants that are difficult to be reduced and not adsorbed by the PRB magnetic biochar permeable wall.

[0016] The PRB magnetic biochar permeable wall electrode plate carbon felt adsorption layer double adsorption structure applied to the electrolyte circulation technology enhanced electrokinetic remediation device has the advantage of further improving the heavy metal removal efficiency, and can further improve the technical route of the electrolyte circulation technology enhanced electrokinetic remediation device to make the treatment effect better.

[0017] The PRB magnetic biochar permeable wall is fixed into a cuboid shape by a polyethylene net fixing layer, the reducible metal pollutants are reduced to metal elements on the surface by the zero-valent iron reduction layer based on the free charge generated by electrolysis, the heavy metal pollutants passing through the zero-valent iron layer are firmly adsorbed by the magnetic biochar layer, and a small amount of metal pollutants passing through the PRB magnetic biochar permeable wall are secondarily adsorbed by the carbon felt adsorption layer uniformly distributed on the electrode plate.

[0018] The present application is a safe and effective pollutant remediation technology, which has the characteristics of no secondary pollution, simple operation, etc., and has good removal efficiency for heavy metals and organic pollutants in low-permeability, multi-phase and heterogeneous soil medium, and low overall cost. Therefore, the electrokinetic remediation technology has been applied to the remediation of heavy metals and organic matter in soil, sludge and sediment.

[0019] The PRB magnetic biochar permeable wall electrode plate carbon felt adsorption layer double adsorption structure of the present application applied to the electrolyte circulation enhanced electrokinetic technology remediation soil heavy metal device can effectively improve the heavy metal ion removal rate of the electrolyte circulation enhanced electrokinetic technology remediation soil heavy metal device, and the average improvement rate of the heavy metal ion removal rate is increased from 68% to 95%. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 The figure is a structural diagram of the PRB magnetic biochar permeable wall electrode plate carbon felt adsorption layer double adsorption structure of the present application. DETAILED DESCRIPTION

[0021] The technical solution of the present application is not limited to the following specific embodiments, but also includes any combination of the specific embodiments.

[0022] Specific embodiment one: the PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure includes a PRB magnetic biochar permeable wall and an electrode plate surface carbon felt adsorption layer 5. The PRB magnetic biochar permeable wall is composed of a first polyethylene net fixed layer 1, an activated carbon zero-valent iron reduction layer 2, a magnetic biochar adsorption layer 3, and a second polyethylene net fixed layer 4 in order. One side of the second polyethylene net fixed layer 4 is connected with the magnetic biochar adsorption layer 3, and the other side is connected with the electrode plate surface carbon felt adsorption layer 5.

[0023] Specific embodiment two: the difference between this embodiment and specific embodiment one is that the activated carbon zero-valent iron reduction layer 2 is filled with zero-valent iron scrap. The rest is the same as specific embodiment one.

[0024] In this embodiment, the zero-valent iron scrap is Leber high-purity reduced iron scrap with a purity of 99.9%, produced by Hebei Leber Metal Material Technology Co., Ltd.

[0025] Specific embodiment three: the difference between this embodiment and specific embodiment one or two is that the magnetic biochar adsorption layer 3 is filled with magnetic biochar granular material. The rest is the same as specific embodiment one or two.

[0026] In this embodiment, the preparation method of the magnetic biochar granular material is as follows:

[0027] I. Take the powder obtained by treating waste distiller's grains as raw material, and calcine it at 500 degrees Celsius for 4 hours under anaerobic conditions to obtain porous biochar;

[0028] II. Preparation of trivalent iron precursor solution: take ethylene glycol as dispersant, add solid trivalent iron salt (ferric chloride hexahydrate) to it, then continue to add sodium acetate and surfactant polyaspartic acid sodium to the ethylene glycol, the mass ratio of ethylene glycol to trivalent iron salt is 7.5:1, the volume ratio of ethylene glycol to sodium acetate is 5.5:1, and the volume ratio of polyaspartic acid sodium to ethylene glycol is 1:2.5. After stirring, a dispersion system, i.e. a trivalent iron precursor solution, is formed;

[0029] III. Solvothermal reaction: mix the biochar and the trivalent iron precursor solution uniformly according to a mass ratio of 1:1.5 to obtain a mixture, and place the mixture in a polytetrafluoroethylene hydrothermal reaction kettle. Under the conditions of a temperature of 85 degrees Celsius and a pressure of 1.5 MPa, perform solvothermal reaction for 30 minutes to obtain a magnetic biochar adsorption material.

[0030] Specific embodiment four: one of the differences between the first three specific embodiments is that the electrode plate surface carbon felt adsorption layer 5 is made of a layer of carbon felt adsorption layer uniformly laid on the electrode plate of the electrolyte circulation enhanced electromotive force technology soil heavy metal remediation device.

[0031] Specific embodiment five: one of the differences between the first four specific embodiments is that the first polyethylene mesh fixed layer 1 has a pore size of 1mm. The others are the same as one of the first four specific embodiments.

[0032] Specific embodiment six: one of the differences between the first five specific embodiments is that the second polyethylene mesh fixed layer 4 has a pore size of 1mm. The others are the same as one of the first five specific embodiments.

[0033] Specific embodiment seven: the PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure in one of the first six specific embodiments is applied to the electrolyte circulation enhanced electromotive force technology soil heavy metal remediation device. A PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is added to the side of the electrode plate near the soil remediation chamber of the electrolyte circulation enhanced electromotive force technology soil heavy metal remediation device. The electrode plate surface carbon felt adsorption layer 5 is made of a layer of carbon felt adsorption layer uniformly laid on the electrode plate, and the electrode plate surface carbon felt adsorption layer 5 is connected to one side of the second polyethylene mesh fixed layer 4.

[0034] The electrolyte circulation technology enhanced electromotive force soil heavy metal removal device of the present embodiment has the model SUSEME-SH and is manufactured by Zigong Zhenxiong Composite Materials Co., Ltd.

[0035] The following experiments are used to verify the effect of the present application:

[0036] Experiment one:

[0037] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure includes a PRB magnetic bioactive carbon permeable wall and an electrode plate surface carbon felt adsorption layer 5. The PRB magnetic bioactive carbon permeable wall is composed of a first polyethylene mesh fixed layer 1, an activated carbon zero-valent iron reduction layer 2, a magnetic bioactive carbon adsorption layer 3, and a second polyethylene mesh fixed layer 4 in order. One side of the second polyethylene mesh fixed layer 4 is connected to the magnetic bioactive carbon adsorption layer 3, and the other side is connected to the electrode plate surface carbon felt adsorption layer 5.

[0038] The activated carbon zero-valent iron reduction layer 2 is filled with zero-valent iron scrap.

[0039] The magnetic bioactive carbon adsorption layer 3 is filled with magnetic bioactive carbon granular material.

[0040] The electrode plate surface carbon felt adsorption layer 5 is made of the electrode plate uniformly laid with a layer of carbon felt adsorption layer.

[0041] The first polyethylene net fixed layer 1 has a pore diameter of 1mm.

[0042] The second polyethylene net fixed layer 4 has a pore diameter of 1mm.

[0043] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is applied to the electrolyte circulation reinforced electromotive force technology soil heavy metal remediation device, and a PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure is arranged near one side of the electrode plate of the electrolyte circulation reinforced electromotive force technology soil heavy metal remediation device.

[0044] The preparation method of the magnetic biochar granular material in the experiment is as follows:

[0045] I. The powder obtained by treating waste vinasse biomass is used as raw material, and is calcined at 500 degrees Celsius for 4 hours under anaerobic conditions to obtain porous biochar;

[0046] II. Preparation of trivalent iron precursor solution: ethylene glycol is used as dispersant, and solid trivalent iron salt (ferric chloride hexahydrate) is added, followed by adding sodium acetate and surfactant polyaspartic acid sodium into the ethylene glycol, the mass ratio of ethylene glycol to trivalent iron salt is 7.5:1, the volume ratio of ethylene glycol to sodium acetate is 5.5:1, and the volume ratio of polyaspartic acid sodium to ethylene glycol is 1:2.5, and after stirring, a dispersion system, i.e. trivalent iron precursor solution, is formed;

[0047] III. Solvothermal reaction: the biochar and the trivalent iron precursor solution are uniformly mixed in a mass ratio of 1:1.5 to obtain a mixture, and the mixture is placed in a polytetrafluoroethylene hydrothermal reaction kettle, and the solvothermal reaction is carried out at a temperature of 85 degrees Celsius and a pressure of 1.5 MPa for 30 minutes to obtain the magnetic biochar adsorption material.

[0048] As Figure 1As shown, in the actual operation of the PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure, heavy metal pollutants move towards the PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure under the action of electromigration, and the reducible heavy metal pollutants are reduced to elemental form under the action of free charges generated by electrolysis and remain in the activated carbon zero-valent iron reduction layer 2; the difficult-to-reduce heavy metal pollutants are adsorbed by the magnetic biochar adsorption layer 3 after passing through the activated carbon zero-valent iron reduction layer 2; and finally, a small amount of stubborn heavy metal pollutants are double-adsorbed by the activated carbon fiber in the electrode plate surface carbon felt adsorption layer 5 after passing through the PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure.

[0049] The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer double adsorption structure of the experiment is applied to the electrolyte circulating enhanced electrokinetic technology for repairing soil heavy metal devices, and the average increase rate of heavy metal ion removal rate is increased from 68% to 95%, which can effectively improve the heavy metal ion removal rate of the electrolyte circulating enhanced electrokinetic technology for repairing soil heavy metal devices.

Claims

1. A dual adsorption structure of PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer, applied to an electrolyte circulation enhanced electrodynamic technology device for remediating heavy metals in soil, characterized by... The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer dual adsorption structure includes a PRB magnetic bioactive carbon permeable wall and an electrode plate surface carbon felt adsorption layer (5). The PRB magnetic bioactive carbon permeable wall is composed of a first polyethylene mesh fixing layer (1), an activated carbon zero-valent iron reduction layer (2), a magnetic biochar adsorption layer (3), and a second polyethylene mesh fixing layer (4) in sequence. One side of the second polyethylene mesh fixing layer (4) is connected to the magnetic biochar adsorption layer (3), and the other side is connected to the electrode plate surface carbon felt adsorption layer (5). The activated carbon zero-valent iron reduction layer (2) filler is zero-valent iron filings; The magnetic biochar adsorption layer (3) filler is magnetic biochar granular material; The carbon felt adsorption layer (5) on the surface of the electrode plate is made by uniformly laying a layer of carbon felt adsorption layer on the electrode plate of the device for remediating heavy metals in soil using electrolyte circulation enhanced electrodynamic technology; The first polyethylene mesh fixing layer (1) has a pore size of 1 mm; The second polyethylene mesh fixing layer (4) has a pore size of 1 mm.

2. The application of the dual adsorption structure of the PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer as described in claim 1, characterized in that... The PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer dual adsorption structure is applied to the electrolyte circulation enhanced electrodynamic technology for soil heavy metal remediation device. A PRB magnetic bioactive carbon permeable wall electrode plate carbon felt adsorption layer dual adsorption structure is added to the side of the electrode plate of the electrolyte circulation enhanced electrodynamic technology for soil heavy metal remediation device near the soil remediation chamber. The carbon felt adsorption layer (5) on the surface of the electrode plate is made by uniformly laying a layer of carbon felt adsorption layer on the electrode plate, and the carbon felt adsorption layer (5) on the surface of the electrode plate is connected to one side of the second polyethylene mesh fixing layer (4).

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