Device for repairing chromium-polluted soil and / or underground water by using electrochemically reinforced minerals

Abstract

The utility model discloses a device for repairing chromium-polluted soil and / or underground water by electrochemically strengthening minerals. The device comprises a power supply, an on-line monitoring control system, an electrode unit and a mineral material, the power supply provides energy for device operation; the on-line monitoring control system is used for monitoring the temperature and humidity, the pH value, the oxidation-reduction potential and the change of current and voltage of the surrounding environment of the electrode unit and adjusting the current and voltage output to the electrode unit; the electrode unit consists of an electrode, a carrier and an electrode sleeve, and is arranged in chromium-contaminated soil and / or underground water; and the mineral material has hexavalent chromium reducing capacity and fixing capacity, and is filled outside the electrode unit sleeve and at the bottom of the carrier and / or used as an electrode coating. According to the device, chromium-containing pollutants are electrically driven to migrate and reduce, and the reduction and fixation of chromium by minerals are strengthened, so that the device is simple and convenient to operate, green and safe, chromium-polluted soil and underground water can be effectively treated, and the problems of high energy consumption, secondary pollution, soil degradation and the like in the traditional remediation technology are solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to soil and groundwater remediation technical field, is applicable to the in-situ or ex-situ remediation of chromium contaminated soil and / or groundwater, especially relates to a kind of electrochemical reinforcement mineral remediation chromium contaminated soil and / or groundwater device. BACKGROUND

[0002] The remediation technology of chromium-contaminated soil and groundwater mainly includes physical remediation, chemical remediation and biological remediation. Physical remediation mainly includes soil replacement, soil removal and isolation, etc. Due to the huge amount of engineering, it is only suitable for treating small range of soil with serious chromium pollution. Chemical remediation mainly uses some reducing agents such as calcium polysulfide, sodium hyposulfite and sodium sulfide, etc. to convert high-toxicity hexavalent chromium into low-toxicity trivalent chromium. Chemical remediation has quick effect but is easy to cause secondary pollution, and is not suitable for low-permeability soil. Biological remediation mainly reduces or fixes hexavalent chromium through the activities of plants and microorganisms, which is eco-friendly and cost-controllable, but the remediation efficiency is not high and it is not suitable for sites with high chromium pollution concentration.

[0003] Electrokinetic remediation and electrochemical remediation are chromium remediation technologies that have emerged in recent years. They have attracted widespread attention because they do not need to add extra electron sources, are not easy to cause secondary pollution, and are suitable for low-permeability soil that is difficult to treat by other remediation methods. Electrokinetic remediation mainly uses electro-migration, electro-osmosis and electrophoresis to remove pollutants by applying a direct current electric field to contaminated soil or water. Electrochemical remediation mainly removes hexavalent chromium through the reducing action of electrodes or the reducing action of coupled microorganisms. However, the current electrokinetic remediation technology has problems such as high energy cost, frequent replacement of electrode materials, obvious focusing effect and soil degradation. Although the electrochemical remediation technology has relatively low energy consumption, it also has problems such as high electrode cost, frequent replacement of electrodes, and insufficient stabilization of chromium.

[0004] Mineral remediation has also been used in the treatment of chromium-contaminated soil or water in recent years. Compared with chemical reagents, mineral materials have certain advantages in the treatment of chromium, which can reduce hexavalent chromium and fix it, reducing the risk of chromium re-oxidation. However, similar to chemical remediation, mineral remediation has certain requirements for the water content and permeability of the contaminated medium, and the amount of engineering is large in in-situ remediation, which limits the application of mineral remediation in in-situ treatment of chromium pollution. SUMMARY

[0005] In order to overcome the defects of the prior art, the utility model discloses a kind of electrochemical strengthening mineral in-situ remediation device of chromium-contaminated soil and / or groundwater.The device is constructed by electrode unit, low-voltage electric field is applied to contaminated medium, the electron transfer of organic matter and microorganism is strengthened, the reduction and fixation of chromium by mineral material are strengthened, avoid the problems such as large-area ploughing of soil, frequent replacement of electrode and secondary treatment of chromium pollutants in conventional electroremediation and mineral remediation technology, while reducing cost and operation difficulty, realize the efficient removal of chromium and reduce the risk of "yellowing back" of chromium.

[0006] To achieve the above object, the utility model adopts the following technical scheme:

[0007] A kind of electrochemical strengthening mineral remediation device of chromium-contaminated soil and / or groundwater, it is characterized in that, including power supply, online monitoring control system, electrode unit and mineral material, wherein the power supply is powered for online monitoring control system;The online monitoring control system includes sensor, adjustable DC regulated power module and data acquisition module, the sensor is arranged in the monitoring site in chromium-contaminated soil and / or groundwater, signal connection between sensor and data acquisition module;The adjustable DC regulated power module is connected with the electrode unit;The electrode unit is composed of electrode, carrier and electrode sleeve, electrode is arranged on carrier, carrier is located in electrode sleeve;The device includes at least two electrode units arranged in chromium-contaminated soil and / or groundwater, one electrode unit is used as anode, its electrode is connected with the positive pole of adjustable DC regulated power module, another electrode unit is used as cathode, its electrode is connected with the negative pole of adjustable DC regulated power module;The mineral material is mineral material with hexavalent chromium reduction capacity and fixation capacity, which is filled in the outside of electrode unit, the bottom of carrier and / or attached as electrode coating on electrode.

[0008] In the electrochemical strengthening mineral remediation device of chromium-contaminated soil and / or groundwater of the utility model, the power supply provides energy for the operation of electrode unit and online monitoring control system;The online monitoring control system monitors the temperature, humidity, pH, oxidation-reduction potential and current voltage (conductivity) etc. of the environment inside and around electrode unit in real time through sensor, and records the measured data of each sensor by data acquisition module;After accepting power supply, online monitoring control system controls the current voltage size and direction between electrodes according to real-time monitoring data.

[0009] Preferably, the adjustable DC regulated power module is used to adjust the voltage and current between electrodes, so that the electric field intensity is 0.02-1V / cm, and the current intensity is 0.2-2A.

[0010] Further, the online monitoring control system further includes an Internet of Things module, which is connected with the data acquisition module and used to upload real-time monitoring data to the cloud.

[0011] Further, the online monitoring control system further comprises a camera for observing the site condition of the contaminated site in real time.

[0012] Further, the power supply comprises a solar panel and a support thereof, a controller, an inverter and a storage battery, wherein the solar panel is installed on the support, the solar panel, the inverter and the storage battery are connected with the controller respectively, the solar panel converts light energy into electric energy, the storage battery stores the converted electric energy, the controller regulates the charging and discharging power of the solar panel, and the inverter converts direct current into alternating current to supply the online monitoring control system.

[0013] The device for repairing chromium-contaminated soil and / or groundwater by electrochemical strengthening of minerals can be provided with two or more electrode units, which are placed in the chromium-contaminated soil and / or groundwater, and can be arranged in a straight line, or arranged according to the vertices of a triangle, a quadrilateral or other polygon, or arranged according to the vertices and center of a triangle, a quadrilateral or other polygon, or arranged in other ways. Figure 2

[0014] Further, the electrodes in the electrode units can be electrode strips or electrode ropes made of graphite, titanium alloy, mixed metal oxide or other corrosion-resistant conductive materials.

[0015] Preferably, the carrier is a PVC, PPR, PE or any other insulating pipe material with certain strength, and the electrodes can be wound on the carrier in a spiral or other irregular manner. Preferably, the carrier is uniformly provided with small holes with a diameter of 0.4-1 cm.

[0016] The electrode sleeve is an insulating pipe made of PVC, PPR, PE or other materials with certain strength and water permeability, and has a diameter larger than that of the carrier. The electrode sleeve is uniformly provided with small holes, and the diameter of the small holes is preferably 0.1-3 mm.

[0017] Further, the device for repairing chromium-contaminated soil and / or groundwater by electrochemical strengthening of minerals comprises a sampling tube, and preferably, a space is left between the electrode sleeve and the carrier for placing the sampling tube.

[0018] The mineral material has the ability to reduce and fix hexavalent chromium, and is selected from the group consisting of pyrrhotite, magnetite, pyrite, pyrite and their natural symbiotic or associated minerals.

[0019] ​Preferably, the mineral material is crushed, ground and sieved to a powder having a particle size of 20-200 mesh. The powdered mineral material is packed into porous bags made of polylactic acid, chitosan, starch-based materials or other biodegradable materials, and the bags are filled into the electrode unit and / or the carrier bottom, and the pore size of the bags is preferably smaller than the particle size of the mineral material. The powdered mineral material can also be fixed on the electrode by an electrically conductive adhesive and air-dried at room temperature as an electrode coating.

[0020] The utility model has the advantages of:

[0021] 1. The utility model provides an acidic environment conducive to the reduction of chromium and an alkaline environment conducive to the precipitation and stabilization of chromium by electrochemical technology.

[0022] 2. The utility model stimulates the activity of indigenous microorganisms in the field by the action of an electric field, strengthens the electron transfer between organic matter and pollutants, and improves the reduction efficiency of chromium.

[0023] 3. The mineral material of the utility model not only reduces hexavalent chromium, but also fixes chromium in the crystal lattice or forms other stable products, reducing the risk of chromium "yellowing".

[0024] 4. The reducing ions released by the mineral material of the utility model can migrate to the contaminated soil or groundwater outside the electrode unit area under the action of an electric field and reduce chromium, avoiding the problem of large amount of reagent addition in mineral or chemical remediation.

[0025] 5. The mineral material of the utility model can enhance the electrical conductivity of contaminated soil or groundwater and accelerate the transfer efficiency between electron donors and hexavalent chromium.

[0026] 6. The mineral material of the utility model can reduce the change of cathode pH, thereby reducing the focusing effect in traditional electrokinetic remediation.

[0027] 7. The electrode material in the utility model has a low replacement frequency, avoiding the frequent replacement of electrodes or composite electrodes in traditional electrokinetic remediation or electrochemical remediation technology.

[0028] 8. The electrode in the utility model is wound on the carrier in a spiral or other irregular manner, and the non-uniform electric field formed reduces the consumption of electric energy on the surface of the electrode.

[0029] 9. The electric field strength between the electrode units in the utility model is low, the required energy consumption is small, the cost of mineral material is controllable, and the power is fully utilized to provide a green and low-carbon remediation device and mode. BRIEF DESCRIPTION OF DRAWINGS

[0030] Figure 1The device is used for electrochemical strengthening mineral to repair chromium contaminated soil and / or underground water.

[0031] Figure 2 The utility model discloses the spatial distribution schematic diagram of electrode unit according to center - triangle, triangle, center - quadrilateral and quadrilateral four ways.

[0032] Figure 3 The utility model discloses the schematic diagram of mineral material electrode coating and electrode combination.

[0033] The main identification in the drawing is as follows:

[0034] 1 is contaminated soil or underground water, 2 is power supply, 3 is on -line monitoring control system, 4 is electrode unit, 5 is mineral material, 6 is quartz sand filter material, 7 is electrode, 8 is carrier, 9 is electrode sleeve, 10 is sensor, 11 is solar cell panel, 12 is controller, 13 is battery, 14 is inverter, 15 is sampling pipe, 16 is camera, 17 is internet of things module, 18 is data acquisition module, 19 is adjustable DC regulated power supply. DETAILED DESCRIPTION

[0035] The device structure of the utility model, practical application scene and technical effect are further described below in combination with the drawings.

[0036] The device of electrochemical strengthening mineral to repair chromium contaminated soil and / or underground water in the following embodiment is basically same, and the basic composition is as shown in the drawing, including power supply 2, on -line monitoring control system 3, electrode unit 4 and mineral material 5, wherein: Figure 1

[0037] Electrode unit 4 is composed of electrode 7, carrier 8 and electrode sleeve 9, and electrode 7 is fixed on carrier 8 and placed in electrode sleeve 9; mineral material 5 is filled in the outside of electrode unit 4, the bottom of carrier 8 and / or as the coating on electrode 7 (see Figure 3 );The space between electrode sleeve 9 and carrier 8 is reserved to place sampling pipe 15;

[0038] On -line monitoring control system 3 includes sensor 10, adjustable DC regulated power supply module 19, data acquisition module 18, internet of things module 17 and camera 16, sensor 10 is used to monitor temperature, humidity, pH, oxidation -reduction potential and conductivity etc. data, and sensor 10 is arranged in electrode unit 4 and other monitoring points, and signal connection exists between sensor 10 and data acquisition module 18;Adjustable DC regulated power supply module 19 is electrically connected with each electrode 7 and is used to adjust the voltage and current between electrode 7;Data acquisition module 18 is used to record the measured data of each sensor 10, and the measured data is uploaded to the cloud through internet of things module 17;Camera 16 is used to observe the on -the -spot condition of contaminated site in real time.​

[0039] The power supply 2 is connected with the online monitoring control system 3, and provides energy for the operation of the electrode unit 4 and the online monitoring control system 3; the power supply 2 comprises a solar panel 11 and a mounting bracket thereof, a controller 12, an inverter 14 and a storage battery 13, wherein the controller 12 is connected with the solar panel 11, the inverter 14 and the storage battery 13 respectively, the solar panel 11 converts light energy into electric energy, and the charging and discharging power of the solar panel 11 is regulated by the controller 12; the storage battery 13 stores the converted electric energy, and the inverter 14 converts direct current into alternating current to supply the online monitoring control system 3.

[0040] Embodiment 1

[0041] This embodiment is a laboratory test of in-situ remediation of chromium-contaminated soil and groundwater by electrochemical strengthening of minerals, and the main body is a rectangular reaction container, which is designed as follows: length 300 mm, width 100 mm, height 100 mm, and water inlet and outlet are arranged at the bottom of both ends of the reaction container. The contaminated medium in the reaction container is configured by 2.5 kg of quartz sand and 800 mL of potassium dichromate solution with a concentration of 1 g / L, the water inlet and outlet of the reaction container are connected by a hose and under the action of a peristaltic pump (Karmel NKP-DC-B08B) to make the chromium-contaminated water body circulate, simulating the flow of groundwater. The power of the solar panel 11 (photosynthetic silicon DJB-18V20WK) in the power supply 2 is 20 W, and the corresponding controller 12 (Lan Sheng SY-100A) and storage battery 13 (photosynthetic silicon GHGN-G12V8AH) are matched. The electrode unit 4 adopts a linear arrangement mode with one cathode and one anode in series, and the distance between adjacent electrode units 4 is 200 mm, and a group is arranged at the center of the reaction container. The electrode 7 is made of graphite rope (Beijing Jinglong Special Carbon Technology Co., Ltd.) made of graphite material, which is wound on the carrier 8 and electrically connected with the storage battery 13, the carrier 8 is selected from a PE pipe with an outer diameter of 20 mm, the electrode sleeve 9 is selected from a PE pipe with an outer diameter of 32 mm, and the electrode sleeve 9 is uniformly distributed on the surface. The holes with a pore size of 1 mm. The potential difference between the cathode and anode of the electrode unit 4 is 5 V. The particle size of the mineral material 5 is 200 mesh, which is introduced to the outside of the electrode sleeve 9 through a hose, and the addition amount of the mineral material 5 is 5% of the initial total chromium amount. After 30 days of remediation, sampling is carried out through the sampling pipe 15, and the detection shows that the removal rate of hexavalent chromium in the contaminated medium is 99.7%.

[0042] Embodiment 2

[0043] A chemical plant is contaminated by chromium residue stacking, and the in-situ pilot test is carried out by using the device, and the soil remediation area is 100 m 2, the repair depth is 2m. The total power of the solar panel 11 (Jiaosan A-class 182MM) in the power supply 2 is 1440W, and is matched with the corresponding controller 12 and the inverter 14 (Huangsi silicon energy 48V 60A 3Kw MPPT inverter integrated machine), and the storage battery 13 (silicon energy storage battery 48V 80AH), and the inverter 14 is electrically connected with the adjustable direct current stabilized power supply module 19 (Maisheng MS305C). The electrode unit 4 adopts a triangular space layout (see Figure 2 ), the distance between the electrode units 4 is 2m, and two groups are arranged. The electrode 7 selects an electrode strip with titanium as the base and attached to a mixed metal oxide coating (Shaanxi Youchuang Environmental Protection Technology Co., Ltd.), and a mineral material coating is bonded on the electrode strip (see Figure 3 ), the electrode strip is wound on the carrier 8 and is electrically connected with the adjustable direct current stabilized power supply module 19 (Maisheng MS305C), the carrier 8 selects a PVC pipe with an outer diameter of 50mm, the electrode sleeve 9 selects a PVC pipe with an outer diameter of 100mm, the surface of the carrier 8 is uniformly distributed with small holes with a pore size of 4mm, and the surface of the electrode sleeve 9 is uniformly distributed with small holes with a pore size of 3mm. The potential difference between the anode and the cathode of the electrode unit 4 is 10V, and the current intensity is 1A. The mineral material 5 has a particle size of 100-200 meshes, is packaged by a sub-packaging bag, is uniformly filled outside the electrode sleeve 9, and the mineral material addition amount is 10% of the total amount of chromium estimated on the site. The sensors 10 (Pu'aisen PR-3001-TR-ECTHPH-N01, Jiandarenke RS-ECH-N01, RS-ORP-N01-3) of temperature and humidity, pH value and conductivity are arranged at the center of the electrode unit group, the center and the four edge areas of the site, the arrangement depth is 1m, and are connected to the data acquisition module 18 (Pu'aisen SN-300YM-4G) and the Internet of Things module 17 (Jiandarenke RS-4G-YM) through RS485 signal, and data is uploaded to the cloud in real time. The camera 16 (Hikvision DS-2DE3Q120MY-T / GLSE) is electrically connected with the inverter 14, and real-time acquisition of the scene picture is used to monitor the pollution site condition. After 30 days of repair, sampling is carried out through the sampling pipe 15, the concentration of hexavalent chromium in the fixed point soil is detected, and the removal rate reaches 98.6%.

[0044] Example 3

[0045] A certain chemical plant is caused by chromium residue stacking to pollute the soil and underground water in a large area, and the device is used for in-situ remediation, and the remediation area is 4000m 2, repair depth 12m, including aquifer. The total power of solar panels 11 (JASO A-class 182MM) in power supply 2 is 3600W, and matches corresponding controller 12 and inverter 14 (photosynthesis silicon energy 96V60A10KwMPPT inverter integrated machine) and storage battery 13 (silicon energy storage battery 12V200AH), and inverter 14 is electrically connected with adjustable direct current stabilized power supply module 19 (Masheng MS305C). Electrode unit 4 adopts central-quadrilateral space layout (see Figure 2 ), the distance between central electrode unit and quadrilateral electrode unit is 6m, a total of five groups are arranged, covering the upper and lower edges of the contaminated area and the seriously contaminated area in the middle of the contaminated area. Electrode 7 selects electrode belt with titanium as the base and attached mixed metal oxide coating (Shaanxi Youchuang Environmental Protection Technology Co., Ltd.), and mineral material coating is bonded on the electrode belt (see Figure 3 ), the electrode belt is wound on carrier 8 and is electrically connected with adjustable direct current stabilized power supply module 19 (Masheng MS305C), carrier 8 selects PVC pipe material with an outer diameter of 50mm, electrode sleeve 9 selects PVC pipe material with an outer diameter of 100mm, carrier 8 surface is uniformly distributed with small holes with a pore size of 4mm, and electrode sleeve 9 surface is uniformly distributed with small holes with a pore size of 3mm. The potential difference between the anode and cathode of electrode unit 4 is 20V, and the current intensity is 1.5A. Mineral material 5 has a particle size of 100-200 meshes, and is packaged in a sub-packaging bag, and the volume of the sub-packaging bag is controlled to be 30x30x30mm 3 , and is uniformly filled with quartz sand filter material 6 in layers outside electrode sleeve 9, and the mineral material is added in an amount of 5% of the total estimated chromium in the site. The pH value, conductivity and oxidation-reduction potential sensors 10 (Purasonic PR-3001-TR-ECTHPH-N01, Jianda Renke RS-ECH-N01, RS-ORP-N01-3) are arranged inside each electrode unit, and are arranged at a depth of 5-12m, and are connected to data acquisition module 18 (Purasonic SN-300YM-4G) and Internet of Things module 17 (Jianda Renke RS-4G-YM) through RS485 signal, and data is uploaded to the cloud in real time. Camera 16 (Hikvision DS-2DE3Q120MY-T / GLSE) is electrically connected with inverter 14, and real-time acquisition of the scene picture is used to monitor the contaminated site condition. After 60 days of repair, sampling is performed through sampling pipe 15, and the average removal rate of hexavalent chromium at each monitoring point is 92.7%.

[0046] Finally, it should be noted that: the above examples are only used to help further understand the technical solutions of the present application and not to limit them, although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand: without departing from the spirit and scope of the present application and the appended claims, various substitutions and modifications are possible. Therefore, the present application should not be limited to the content disclosed in the examples.

Claims

1. An apparatus for electrochemically strengthening minerals to remediate chromium-contaminated soil and / or groundwater, characterized by, The device comprises a power supply, an online monitoring control system, an electrode unit and a mineral material, wherein the power supply supplies power to the online monitoring control system; the online monitoring control system comprises a sensor, an adjustable DC voltage stabilizing power supply module and a data acquisition module, the sensor is arranged at a monitoring site in the chromium-contaminated soil and / or groundwater, and the sensor is signal-connected with the data acquisition module; the adjustable DC voltage stabilizing power supply module is connected with the electrode unit; the electrode unit is composed of an electrode, a carrier and an electrode sleeve, the electrode is arranged on the carrier, and the carrier is located in the electrode sleeve; the device comprises at least two electrode units arranged in the chromium-contaminated soil and / or groundwater, one electrode unit serves as an anode, and the electrode thereof is connected with the positive electrode of the adjustable DC voltage stabilizing power supply module; the other electrode unit serves as a cathode, and the electrode thereof is connected with the negative electrode of the adjustable DC voltage stabilizing power supply module; the mineral material is a mineral material having the ability to reduce and fix hexavalent chromium, which is filled outside the electrode unit, at the bottom of the carrier and / or attached to the electrode as an electrode coating.

2. The apparatus of claim 1, wherein, The online monitoring control system further comprises an Internet of Things module for uploading real-time monitoring data to the cloud, and the Internet of Things module is connected with the data acquisition module.

3. The apparatus of claim 1, wherein, The online monitoring control system further comprises a camera for observing the site conditions of the contaminated site in real time.

4. The apparatus of claim 1, wherein, The power supply comprises a solar cell panel and a support thereof, a controller, an inverter and a storage battery, wherein the solar cell panel is installed on the support, the solar cell panel, the inverter and the storage battery are respectively connected with the controller, the solar cell panel converts light energy into electric energy, the charging and discharging power of the solar cell panel is regulated by the controller, and the electric energy is stored in the storage battery; the inverter for converting direct current into alternating current is connected with the online monitoring control system.

5. The apparatus of claim 1, wherein, The electrode unit is placed in the chromium-contaminated soil and / or groundwater, and the spatial arrangement mode is linear arrangement, or the spatial arrangement is performed in the mode of polygon vertex or polygon vertex and center.

6. The apparatus of claim 1, wherein, The electrode is an electrode strip or electrode rope made of conductive material, which is wound on the carrier; the carrier and the electrode sleeve are both insulating pipes, and small holes are uniformly distributed on the carrier and the electrode sleeve.

7. The apparatus of claim 6, wherein, The hole diameter of the small holes on the carrier is 0.4-1 cm, and the hole diameter of the small holes on the electrode sleeve is 0.1-3 mm.

8. The apparatus of claim 1, wherein, The device further comprises a sampling tube, and a space for placing the sampling tube is left between the electrode sleeve and the carrier.

9. The apparatus of claim 1, wherein, The powdered mineral material is packaged in a porous packaging bag made of biodegradable material and filled outside the electrode unit and / or at the bottom of the carrier; and / or, the powdered mineral material is fixed on the electrode by conductive adhesive to form an electrode coating. The device comprises a power supply, an online monitoring control system, an electrode unit and a mineral material, wherein the power supply supplies power to the online monitoring control system; the online monitoring control system comprises a sensor, an adjustable DC voltage stabilizing power supply module and a data acquisition module, the sensor is arranged at a monitoring site in the chromium-contaminated soil and / or groundwater, and the sensor is signal-connected with the data acquisition module; the adjustable DC voltage stabilizing power supply module is connected with the electrode unit; the electrode unit is composed of an electrode, a carrier and an electrode sleeve, the electrode is arranged on the carrier, and the carrier is located in the electrode sleeve; the device comprises at least two electrode units arranged in the chromium-contaminated soil and / or groundwater, one electrode unit serves as an anode, and the electrode thereof is connected with the positive electrode of the adjustable DC voltage stabilizing power supply module; the other electrode unit serves as a cathode, and the electrode thereof is connected with the negative electrode of the adjustable DC voltage stabilizing power supply module; the mineral material is a mineral material having the ability to reduce and fix hexavalent chromium, which is filled outside the electrode unit, at the bottom of the carrier and / or attached to the electrode as an electrode coating. The online monitoring control system further comprises an Internet of Things module for uploading real-time monitoring data to the cloud, and the Internet of Things module is connected with the data acquisition module. The online monitoring control system further comprises a camera for observing the site conditions of the contaminated site in real time. The power supply comprises a solar cell panel and a support thereof, a controller, an inverter and a storage battery, wherein the solar cell panel is installed on the support, the solar cell panel, the inverter and the storage battery are respectively connected with the controller, the solar cell panel converts light energy into electric energy, the charging and discharging power of the solar cell panel is regulated by the controller, and the electric energy is stored in the storage battery; the inverter for converting direct current into alternating current is connected with the online monitoring control system. The electrode unit is placed in the chromium-contaminated soil and / or groundwater, and the spatial arrangement mode is linear arrangement, or the spatial arrangement is performed in the mode of polygon vertex or polygon vertex and center. The electrode is an electrode strip or electrode rope made of conductive material, which is wound on the carrier; the carrier and the electrode sleeve are both insulating pipes, and small holes are uniformly distributed on the carrier and the electrode sleeve. The hole diameter of the small holes on the carrier is 0.4-1 cm, and the hole diameter of the small holes on the electrode sleeve is 0.1-3 mm. The device further comprises a sampling tube, and a space for placing the sampling tube is left between the electrode sleeve and the carrier. The powdered mineral material is packaged in a porous packaging bag made of biodegradable material and filled outside the electrode unit and / or at the bottom of the carrier; and / or, the powdered mineral material is fixed on the electrode by conductive adhesive to form an electrode coating.

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