CN201454978U - Electrodynamic adsorption plant compound remediation device for heavy metal polluted soil - Google Patents

Abstract

The utility model discloses a heavy metal polluted soil electrokinetic adsorbing and compounding remediation device for plants, which comprises an anodic area, a cathode area, a power supply, porous medium partition boards and porous medium adsorption material, wherein anode buffer solution and cathode buffer solution are respectively filled in the anodic area and the cathode area which are respectively connected to two poles of the power supply; the porous medium partition boards and the porous medium adsorption material are sequentially respectively arranged from the inside to the outside on a surface of the anodic area opposite to the cathode area and on a surface of the cathode area opposite to the anodic area; and a remediation area for remedying heavy metal polluted soil for planting plant roots is formed between every two porous medium adsorption material layers. Under the action of voltage power, the heavy metal polluted soil electrokinetic adsorbing and compounding remediation device for plants is capable of quickening desorption of heavy metal on soil solidity and increasing density of heavy metal in soil solution in order to strengthen absorption and accumulation of the plant and greatly increase diversity and vitality of microbial populations in soil, thereby increasing the crop yield.

Description

Electrodynamic adsorption plant compound remediation device for heavy metal polluted soil

technical field

The utility model relates to a device for repairing heavy metal soil, in particular to an electrodynamic adsorption plant composite repair device for heavy metal polluted soil.

Background technique

Heavy metal pollution in soil comes from mining, smelting, urban waste, fertilizer impurities and sewage sediments, etc. The high accumulation of heavy metals in soil directly affects the yield of grains and reduces their quality. Even if the concentration of heavy metals is not high, it may Hinders the diversity and viability of microbial populations in soils, thereby severely affecting the biomass and fertility of soils that are the basis for nutrient cycling and sustainable agriculture. Therefore, the removal of heavy metals in soil and water has become an urgent problem for human beings.

Direct electrokinetic in-situ removal of heavy metals. Due to the H ⁺ and OH ^- generated on the anode and cathode, the pH of the anode drops below 2, and the pH of the cathode rises above 12. H ⁺ and OH ^- migrate to the cathode and anode under the action of an electric field, respectively. Diffusion affects chemical processes throughout the soil system. Hydrogen ions are conducive to the desorption of substances from the soil surface and the dissolution of salts in the soil, and reduce the soil electroosmotic coefficient and zeta potential, which weakens the electroosmotic flow; the migration of hydroxide ions will lead to the early precipitation of metal ions and further Reduce the removal efficiency; the cations of some amphoteric metals may also become acid radical anions in an alkaline environment and change the migration direction; the formation of precipitates blocks the soil voids and increases the voltage drop and energy consumption. Existing research results have shown that the direct in-situ removal method often has low treatment efficiency because it cannot well control the pH change of the soil system. The change of pH affects the adsorption and desorption, precipitation and dissolution of ions in the soil and affects the speed of electrodialysis, which will have a significant impact on the existence and migration characteristics of heavy metals in the soil. Therefore, how to control soil pH is one of the key issues in soil electrokinetic remediation. .

Utility model content

The utility model overcomes the above-mentioned shortcomings, and provides a method that can change the physical and chemical properties of the soil such as oxidation-reduction potential and pH value, accelerate the desorption of heavy metals on soil solids, and increase the concentration of heavy metals in the soil solution, thereby strengthening the absorption of plants. A device for remediating heavy metal-contaminated soil compounded with accumulated electrokinetic adsorption plants.

In order to achieve the above object, the utility model is realized through the following technical solutions:

An electrodynamic adsorption plant composite restoration device for heavy metal contaminated soil, which includes an anode area, a cathode area and a power supply, and is characterized in that it also includes a porous medium separator and a porous medium adsorption material, and the anode area and the cathode area are respectively installed into the anode buffer solution and the cathode buffer solution, and respectively connected to the two poles of the power supply; the opposite surfaces of the anode area and the cathode area and the opposite surfaces of the cathode area and the anode area are respectively arranged in sequence from the inside to the outside. Porous medium separators and porous A medium adsorption material layer, forming a restoration area for repairing the heavy metal contaminated soil of plant roots between the two porous medium adsorption material layers; the anode buffer solution and the cathode buffer solution in the anode area and the cathode area are separated by porous media. The plates are in contact with the porous media adsorption material.

The power supply is a polarity switchable power supply, so that the polarity of the anode area and the cathode area are connected by switching the polarity of the electric field.

The pores of the porous medium separator are 0.01mm-1mm.

The porous medium adsorption material layer is bamboo charcoal or activated carbon.

Under the action of voltage dynamics, the utility model reacts with electrochemical elements in the soil solution near the electrode, changes the physical and chemical properties such as oxidation-reduction potential and pH value in the soil, accelerates the desorption of heavy metals on soil solids, and increases the concentration of heavy metals in the soil solution, thereby Strengthen the absorption and accumulation of plants, greatly increase the diversity and vitality of the microbial population in the soil, and increase the yield of crops.

Description of drawings

The utility model is described in detail below in conjunction with accompanying drawing and specific embodiment;

Figure 1 is a schematic diagram of the utility model for remediating heavy metal-contaminated soil.

Detailed ways

In order to make the technical means, creative features, goals and effects achieved by the utility model easy to understand, the utility model will be further elaborated below in conjunction with specific embodiments.

Referring to Fig. 1: An electrodynamic adsorption plant composite repair heavy metal contaminated soil device, it includes an anode area 3, a cathode area 4 and a power supply 5, it also includes a porous medium separator 1, 1a and a porous medium adsorption material 2, 2a, the anode The anode buffer solution and the cathode buffer solution are filled in the area 3 and the cathode area 4 respectively, an anode 6 is inserted in the anode area 3, a cathode 7 is inserted in the cathode area 4, and the anode 6 and the cathode 7 are respectively connected to the two poles of the power supply 5 The power supply 5 is a polarity switchable power supply, so that the polarities of the anode area 3 and the cathode area 4 are connected by switching the polarity of the electric field; on the opposite surface 11 of the anode area 3 and the cathode area 4, they are sequentially arranged from the inside to the outside Porous medium separator 1 and porous medium adsorption material layer 2, on the opposite surface 12 of the cathode region 4 and the anode region 3, the porous medium separator 1a and the porous medium adsorption material layer 2a are sequentially arranged from the inside to the outside. Between the material layers 2 and 2a, a remediation zone 9 for remediating the heavy metal-contaminated soil of the plant root system 8 is formed; the anode buffer solution and the cathode buffer solution in the anode zone 3 and the cathode zone 4 pass through the porous medium separator 1, 1a and the The porous medium adsorption material layers 2 and 2a are in contact with each other, the pores of the porous medium separators 1 and 1a are 0.01mm-1mm, and the porous medium adsorption material layers 2 and 2a are bamboo charcoal or activated carbon.

The utility model uses graphite as the anode 6 and the cathode 7 to be connected to the two ends of the power supply 5 respectively, and is placed in the anode area 3 and the cathode area 4, and the anode buffer and the cathode buffer are respectively stored in the anode area 3 and the cathode area 4. , the utility model is shown in Figure 1, from the anode area 3 to the cathode area 4, the porous medium separator 1, the porous medium adsorption material layer 2 for adsorbing metal, the restoration area 9 for the heavy metal polluted soil to be treated, and the planting plant are arranged successively. Root system 8, porous media adsorption material layer 2a for adsorbing heavy metals, and porous media separator 1a.

Under the action of electromotive force, the heavy metal ions in the soil migrate from the cathode area 4 to the anode area 3, so that the heavy metal ions accumulate on the soil surface and near the roots of planted plants for repair and prevent them from entering the deep soil. , 1a further prevents the diffusion of heavy metal ions from pollution. In order to prevent the pH value of the cathode area 4 from rising and the pH value of the anode area 3 from falling, the anode buffer and the cathode buffer are used in the anode area 3 and cathode area 4 respectively to regulate circulation. The following electrode reactions occur during electrokinetic restoration:

Anode: 2H ₂ O-4e-→O ₂ +4H+E0＝-1.23V

Cathode: 2H ₂ O+2e-→H ₂ +2OH-E0＝-0.83V

Due to the electrolysis of water, the pH value near the electrode changes, wherein the anode 6 generates H ⁺ to make the anode region 3 appear acidic (the pH value may drop to about 2), and the cathode 7 generates ^OH- to make the cathode region 4 appear alkaline ( pH value may rise to about 12), at the same time, the positively charged H ⁺ moves to the cathode zone 4, and the negatively charged OH ^- moves to the anode zone 3, forming an acidic migration zone and an alkaline migration zone, respectively.

Insert the anode area 3 and ^the cathode ^area 4 of ^the utility model into the soil or groundwater area polluted by heavy metals. ⁺ and other heavy metals migrate from the cathode region 4 to the anode region 3, and in the porous medium adsorption material layer 2 such as the bamboo carbon adsorption region, each heavy metal ion is adsorbed and removed; the role of the porous medium separator 1, 1a is to pass through the porous medium separator 1, 1a, the dilute anode buffer solution and the dilute cathode buffer solution are in contact with the porous media adsorption material layers 2 and 2a respectively, and adjust the pH values of the porous media adsorption material layers 2 and 2a to prevent the rise of the pH value of the cathode region 4 and the pH value of the anode region 3 , and can isolate heavy metal ions from being adsorbed on the electrode. The pore size of the porous medium separator is between 0.01mm and 1mm, and generally 0.07mm is the best. In addition, the method of switching the polarity of the electric field is used to achieve the purpose of adjusting the pH value of the soil. Under the action of electrokinetic force, ions accumulate on the soil surface and near the roots of remedial plants for remediation.

The basic principles and main features of the present utility model and the advantages of the present utility model have been shown and described above. Those skilled in the art should understand that the utility model is not limited by the above-mentioned embodiments. The above-mentioned embodiments and descriptions only illustrate the principle of the utility model. Without departing from the spirit and scope of the utility model, the utility model The new model also has various changes and improvements, and these changes and improvements all fall within the scope of the claimed utility model. The scope of protection required by the utility model is defined by the appended claims and their equivalents.

Claims (4)

1. electric power is adsorbed the compound restoration of soil polluted by heavy metal device of plant, it comprises anode region, cathodic region and power supply, it is characterized in that, it also comprises porous media dividing plate and porous media adsorbing material, install anode buffer solution and negative electrode cushioning liquid in described anode region and the cathodic region respectively, and join with two poles respectively; Be provided with porous media dividing plate and porous media adsorbing material layer on the opposite face of the opposite face in described anode region and cathodic region and cathodic region and anode region respectively successively from inside to outside, between two porous media adsorbing material floor, be formed for repairing the reparation district of the heavy-metal contaminated soil of serike root system.

2. the compound restoration of soil polluted by heavy metal device of electric power absorption plant according to claim 1 is characterized in that described power supply is the convertible power supply of polarity.

3. the compound restoration of soil polluted by heavy metal device of electric power absorption plant according to claim 1 is characterized in that the hole of described porous media dividing plate is 0.01mm-1mm.

4. the compound restoration of soil polluted by heavy metal device of electric power absorption plant according to claim 1 is characterized in that described porous media adsorbing material layer is bamboo charcoal or active carbon.

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