Three-dimensional electrodynamic force chromium-contaminated soil remediation system based on solar energy storage

Abstract

The three-dimensional electrodynamic force chromium-contaminated soil remediation system based on solar energy storage comprises a remediation area built in situ along chromium-contaminated soil, and an anode electrolysis chamber and a cathode electrolysis chamber are arranged at the two ends of the remediation area correspondingly. Separation plates with holes are arranged between the repairing area and the anode electrolysis chamber and between the repairing area and the cathode electrolysis chamber, graphite felt electrodes are arranged in the anode electrolysis chamber and the cathode electrolysis chamber and connected with a direct-current power supply, and the direct-current power supply is further connected with a solar photovoltaic panel; wherein the remediation area comprises a plurality of soil chambers which are arranged in sequence, and a three-dimensional electrode is arranged in each soil chamber. According to the in-situ remediation device, in-situ remediation operation of the chromium-contaminated soil can be continuously carried out for a long time, meanwhile, the three-dimensional electrode introduced into the soil chamber not only improves the conductivity, but also can effectively weaken the focusing phenomenon, the remediation efficiency is guaranteed, the manual labor requirement for remediation of the chromium-contaminated soil is reduced, and development of soil remediation is facilitated.

Description

Technical Field

[0001] The present invention belongs to the technical field of soil remediation, and particularly relates to a three-dimensional electrokinetic chromium-contaminated soil remediation system based on solar energy storage. Background Art

[0002] As an important environmental risk source, the over-standard rate of heavy metal chromium is 1.1% (seventh among heavy metals). In soil, it mainly exists in the forms of trivalent chromium (Cr(Ⅲ)) and hexavalent chromium Cr(Ⅵ). Cr(Ⅲ) has relatively low toxicity, but the high toxicity and strong mobility of Cr(Ⅵ) pose a significant threat to human health and safety.

[0003] Regarding the currently common chromium-contaminated soil remediation technologies, in the phytoremediation system, there are less than 10 globally recognized chromium hyperaccumulator plants, and the annual average remediation efficiency is generally lower than 0.1 mg / kg, which is only applicable to low-concentration contaminated sites. Although the chemical leaching technology has a short treatment cycle, the use of strong acids / chelating agents not only destroys the soil aggregate structure but may also activate passivated heavy metals. Improper treatment of the leaching waste liquid will also form secondary pollution. In the coexistence system of complex valence chromium (Cr(Ⅲ) / Cr(Ⅵ)), the reduction / adsorption efficiency of microbial remediation drops sharply, and the remediation effect is significantly affected by external conditions such as temperature and humidity. Although the chemical reduction method can quickly convert Cr(Ⅵ) through iron-based materials, it is prone to redox potential reversal, resulting in the reactivation of solidified chromium.

[0004] In comparison, the electrokinetic method can directly remove chromium from the soil and is a most promising in-situ remediation technology. However, during the electrokinetic remediation of chromium-contaminated soil, OH - is electrolyzed at the cathode, and H + is electrolyzed at the anode. Under the action of electroosmosis, OH - and Cr(Ⅵ) migrate to the anode, and H + , Cr(Ⅲ) and other metal cations migrate to the cathode. OH - precipitates and accumulates with Cr(Ⅲ) and other metal cations in the middle of the soil chamber, that is, the pH focusing phenomenon occurs, the conductivity decreases, resulting in electroosmotic flow interruption, the soil temperature rises, forming a vicious cycle, bringing potential safety hazards, and the removal effect is severely inhibited.

[0005] In addition, the electrokinetic method consumes a relatively high amount of energy and has a large carbon footprint, and it is also difficult to meet the requirements of low-carbon green remediation and continuous remediation. Summary of the Invention

[0006] The object of the present invention is to overcome the defects of the prior art and provide a three-dimensional electrokinetic chromium-contaminated soil remediation system based on solar energy storage, which can continuously carry out in-situ remediation operations on chromium-contaminated soil for a long time, consume less energy, and at the same time, the three-dimensional electrodes introduced in the soil chamber can not only improve the conductivity, but also effectively weaken the focusing phenomenon, ensure the remediation efficiency, reduce the labor demand for chromium-contaminated soil remediation, be applicable to areas with inconvenient transportation, harsh climate and high labor costs, and is conducive to the development of soil remediation.

[0007] The object of the present invention is achieved by the following technical solutions:

[0008] A three-dimensional electrokinetic chromium-contaminated soil remediation system based on solar energy storage includes a remediation area established in-situ along the chromium-contaminated soil. An anodic electrolysis chamber and a cathodic electrolysis chamber are respectively arranged at both ends of the remediation area. A perforated separator is arranged between the remediation area and the anodic electrolysis chamber and between the remediation area and the cathodic electrolysis chamber. The outer surface of the perforated separator is wrapped with a filter element. Graphite felt electrodes are arranged in both the anodic electrolysis chamber and the cathodic electrolysis chamber. The graphite felt electrodes are connected to a DC power supply, and the DC power supply is also connected to a solar photovoltaic panel;

[0009] Among them, the remediation area includes a plurality of sequentially arranged soil chambers, and three-dimensional electrodes are arranged in each soil chamber;

[0010] Through this embodiment, a remediation system is established in-situ along the chromium-contaminated soil. The solar photovoltaic panel arranged above provides a continuous remediation power supply for the system. The three-dimensional electrodes filled in the soil chamber can effectively avoid the occurrence of focusing in the middle area of the soil, that is, weaken the focusing phenomenon, maintain the conductivity, avoid electroosmotic flow interruption, save energy, reduce carbon emissions, and ensure the remediation effect.

[0011] In one embodiment, the three-dimensional electrode is made of sulfurized nano-zero valent iron material;

[0012] Through this embodiment, under the action of the electric field force, Cr(Ⅲ) and other metal cations migrate to the cathodic electrolysis chamber, and Cr(Ⅵ) migrates to the anodic electrolysis chamber. The sulfurized nano-zero valent iron introduced in the soil chamber as a three-dimensional electrode can effectively weaken the focusing phenomenon, maintain the conductivity, improve the removal rate of trivalent chromium and hexavalent chromium, improve the energy utilization rate, and reduce the degree of soil damage.

[0013] In one embodiment, the preparation method of the sulfurized nano-zero valent iron material is as follows:

[0014] In a mixed solution with a concentration of 10.0 g / L of NaBH 4 and a concentration of 3.0 g / L of Na 2 S 2 O 4 N is introduced into the mixed solution2 Stir at a rate of 10 mL / min while adding FeCl with a concentration of 4.0 g / L 3 solution, and then react in an N 2 atmosphere for 30 min, and separate the particles with a magnet.

[0015] In one embodiment, the repair area is equally spaced to divide into a plurality of the soil chambers, and each of the soil chambers is provided with a voltmeter to measure the voltage of each of the soil chambers.

[0016] In one embodiment, electrolyte outlets are provided on the outer surfaces of both the anode electrolysis chamber and the cathode electrolysis chamber, and the electrolyte outlets are connected to an electrolyte storage tank through a peristaltic pump.

[0017] In one embodiment, it further includes a controller, the controller is connected to the solar photovoltaic panel, the controller is further connected to a storage battery, the storage battery is respectively connected to the DC power supply and the peristaltic pump, the anode of the DC power supply is connected to the graphite felt electrode of the anode electrolysis chamber, and the cathode of the DC power supply is connected to the graphite felt electrode of the cathode electrolysis chamber.

[0018] In one embodiment, a perforated electrode fixing plate is sleeved on the graphite felt electrodes of both the anode electrolysis chamber and the cathode electrolysis chamber, and an electrode fixing clip is further provided on the top of the perforated electrode fixing plate.

[0019] In one embodiment, the filter element is filter paper.

[0020] In one embodiment, the controller is respectively connected to the solar photovoltaic panel and the storage battery through wires.

[0021] In one embodiment, the controller, the storage battery and the DC power supply are all arranged below the solar photovoltaic panel and are arranged in sequence from top to bottom in the vertical direction.

[0022] The beneficial effects of the present invention are as follows:

[0023] (1) It provides an electrokinetic remediation system for chromium-contaminated soil, which can continuously perform in-situ remediation operations on chromium-contaminated soil for a long time, consumes less energy. At the same time, the three-dimensional electrodes introduced into the soil chamber not only improve the conductivity, but also can effectively weaken the focusing phenomenon, ensure the remediation efficiency, reduce the manpower labor demand for chromium-contaminated soil remediation, and are applicable to areas with inconvenient transportation, harsh climate and high labor costs, which is beneficial to the development of soil remediation.

[0024] (2) The sulfurized nano-zero-valent iron introduced into the soil chamber as a three-dimensional electrode can effectively weaken the focusing phenomenon and reduce OH -Precipitation and accumulation occur in the middle of the soil chamber with Cr(Ⅲ) and other metal cations, maintaining the conductivity, increasing the removal rates of trivalent chromium and hexavalent chromium, improving the energy utilization rate, and reducing the degree of soil damage. Description of the Drawings

[0025] The present invention will be described in more detail below based on embodiments and with reference to the drawings. Among them:

[0026] Figure 1 Shows a schematic diagram of the system of the present invention;

[0027] In the drawings, the same components are denoted by the same reference numerals. The drawings are not drawn to actual scale.

[0028] Reference Numerals:

[0029] 1 - Graphite felt electrode, 2 - Electrode fixing clip, 3 - Perforated electrode fixing plate, 4 - Filter paper, 5 - Perforated separator, 6 - Soil chamber, 7 - Voltmeter, 8 - Three-dimensional electrode, 9 - Anodic electrolysis chamber, 10 - Cathodic electrolysis chamber, 11 - Electrolyte outlet, 12 - Peristaltic pump, 13 - Anodic electrolyte storage tank, 14 - Cathodic electrolyte storage tank, 15 - DC power supply, 16 - Storage battery, 17 - Controller, 18 - Solar photovoltaic panel. Detailed Embodiments

[0030] The present invention will be further described below with reference to the drawings.

[0031] The present invention provides a three-dimensional electrokinetic remediation system for chromium-contaminated soil based on solar energy storage, as Figure 1 shown, including a remediation area established along the chromium-contaminated soil, an anodic electrolysis chamber and a cathodic electrolysis chamber are respectively arranged at both ends of the remediation area, a perforated separator is arranged between the remediation area and the anodic electrolysis chamber and between the remediation area and the cathodic electrolysis chamber, a filter member is wrapped on the outer surface of the perforated separator, graphite felt electrodes are arranged in both the anodic electrolysis chamber and the cathodic electrolysis chamber, the graphite felt electrodes are connected to a DC power supply, and the DC power supply is also connected to a solar photovoltaic panel;

[0032] Among them, the remediation area includes a plurality of soil chambers arranged in sequence, a three-dimensional electrode is arranged in each soil chamber, and the filter member is filter paper;

[0033] It should be noted that the three-dimensional electrode is made of sulfidated nano-zero-valent iron material, and its preparation method is as follows:

[0034] In a mixed solution with a concentration of 10.0 g / L of NaBH 4 and a concentration of 3.0 g / L of Na 2 S 2 O 4 N is introduced into the mixed solution2 Stir at a rate of 10 mL / min while adding FeCl with a concentration of 4.0 g / L 3 solution, and then react in an N 2 atmosphere for 30 min, and separate the particles with a magnet;

[0035] That is, the introduced sulfidated nano-zero valent iron serves as a three-dimensional electrode, which can effectively weaken the focusing phenomenon and reduce the precipitation and accumulation of OH - with Cr(III) and other metal cations in the middle of the soil chamber, maintain the conductivity, improve the removal rates of trivalent chromium and hexavalent chromium, improve the energy utilization rate, reduce the degree of soil damage, and can continuously carry out in-situ remediation operations of chromium-contaminated soil for a long time, consume less energy, reduce the labor demand for the remediation of chromium-contaminated soil, be applicable to areas with inconvenient transportation, harsh climate and high labor costs, and be conducive to the development of soil remediation;

[0036] In one embodiment, a plurality of the soil chambers are equally spaced in the repair area, and a voltmeter is provided in each soil chamber to measure the voltage of each soil chamber;

[0037] Specifically, as Figure 1 shown, the repair area is equally divided into five soil chambers, and a voltmeter is provided in each soil chamber to monitor the voltage magnitude of each soil chamber in real time;

[0038] In one embodiment, as Figure 1 shown, electrolyte outlets are provided on the outer surfaces of the anode electrolysis chamber and the cathode electrolysis chamber, and the electrolyte outlets are connected to an electrolyte storage tank through a peristaltic pump, that is, to prevent the electrolyte liquid levels in the anode electrolysis chamber and the cathode electrolysis chamber from being too high or too low;

[0039] In one embodiment, as Figure 1 shown, the system further includes a controller, the controller is connected to the solar photovoltaic panel, the controller is also connected to a storage battery, the storage battery is respectively connected to the DC power supply and the peristaltic pump, the anode of the DC power supply is connected to the graphite felt electrode of the anode electrolysis chamber, the cathode of the DC power supply is connected to the graphite felt electrode of the cathode electrolysis chamber, the controller is respectively connected to the solar photovoltaic panel and the storage battery through wires, and the controller, the storage battery and the DC power supply are all arranged below the solar photovoltaic panel and are arranged in sequence from top to bottom in the vertical direction;

[0040] In this embodiment, a solar photovoltaic panel and a storage battery are provided. The solar photovoltaic panel is used for power generation and the electric energy is transmitted to the storage battery for storage. Then, the storage battery supplies power to the peristaltic pump and the DC power supply. The solar photovoltaic panel is located above the in-situ chromium-contaminated soil. On the one hand, it ensures the power generation efficiency of the solar photovoltaic panel, and on the other hand, this system can be directly installed using the area of the soil to be repaired;

[0041] In one embodiment, electrode fixing clips are provided on the graphite felt electrodes of both the anode electrolysis chamber and the cathode electrolysis chamber;

[0042] In one embodiment, first, a mixed solution with the concentrations of NaBH 4 and Na 2 S 2 O 4 being 10.0 g / L and 3.0 g / L respectively is prepared. At a rate of 10 mL / min, while stirring and introducing N 2 , it is added to a FeCl 3 solution with a concentration of 4.0 g / L; then, it reacts in an N 2 atmosphere for 30 min, and the particles are separated by a magnet. Before the repair starts, the three-dimensional electrode of sulfidated nano-zero-valent iron is uniformly put into the soil chamber, and the dosing concentration is 50% of the chromium concentration in the contaminated soil. The DC power supply controls the voltage gradient in the soil chamber to be 0.3 - 0.5 V / cm. Under the action of the electric field force, Cr(Ⅲ) and other metal cations migrate to the cathode electrolysis chamber, and Cr(Ⅵ) migrates to the anode electrolysis chamber. The three-dimensional electrode improves the soil conductivity, weakens the focusing phenomenon, reduces the waste of electric energy, and improves the removal efficiency of chromium;

[0043] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "upper", "lower", "bottom", "top", "front", "rear", "inner", "outer", "left", "right", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation of the present invention.

[0044] Although the present invention has been described herein with reference to specific embodiments, it should be understood that these embodiments are merely examples of the principles and applications of the present invention. Therefore, it should be understood that many modifications can be made to the exemplary embodiments, and other arrangements can be designed, as long as they do not deviate from the spirit and scope of the present invention defined by the appended claims. It should be understood that different dependent claims and the features described herein can be combined in a manner different from that described in the original claims. It should also be understood that the features described in connection with a single embodiment can be used in other described embodiments.

Claims

1. A three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage, characterized in that: The invention comprises a remediation area established in situ along the chromium-contaminated soil, wherein an anode electrolysis chamber and a cathode electrolysis chamber are respectively arranged at both ends of the remediation area, a perforated isolation plate is arranged between the remediation area and the anode electrolysis chamber and between the remediation area and the cathode electrolysis chamber, a filter is wrapped on the outer surface of the perforated isolation plate, and graphite felt electrodes are arranged in the anode electrolysis chamber and the cathode electrolysis chamber, and the graphite felt electrodes are connected to a direct current power supply, and the direct current power supply is also connected to a solar photovoltaic panel; Wherein, the repair area includes a plurality of soil chambers arranged in sequence, and each of the soil chambers is provided with a three-dimensional electrode.

2. According to claim 1, a three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage is characterized in that: The three-dimensional electrode is made of sulfide nano zero-valent iron material.

3. According to claim 2, a three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage is characterized in that: The preparation method of the sulfide nano zero-valent iron material is as follows: N2 was introduced into a mixed solution of NaBH4 with a concentration of 10.0 g / L and Na2S2O4 with a concentration of 3.0 g / L and stirred at a rate of 10 mL / min. At the same time, a FeCl3 solution with a concentration of 4.0 g / L was added, and the mixture was reacted in a N2 atmosphere for 30 minutes, and the particles were separated using a magnet.

4. According to the three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage according to claim 1, it is characterized in that: The repair area is divided into a plurality of soil chambers at equal intervals, and each soil chamber is provided with a voltmeter to measure the voltage of each soil chamber.

5. According to the three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage according to claim 1, it is characterized in that: The outer surfaces of the anode electrolysis chamber and the cathode electrolysis chamber are both provided with electrolyte outlets, and the electrolyte outlets are connected to the electrolyte storage tank through a peristaltic pump.

6. A three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage according to claim 5, characterized in that: It also includes a controller, which is connected to the solar photovoltaic panel. The controller is also connected to a battery, and the battery is respectively connected to the DC power supply and the peristaltic pump. The anode of the DC power supply is connected to the graphite felt electrode of the anode electrolysis chamber, and the cathode of the DC power supply is connected to the graphite felt electrode of the cathode electrolysis chamber.

7. According to claim 1, a three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage is characterized in that: The graphite felt electrodes of the anode electrolysis chamber and the cathode electrolysis chamber are sleeved with a holed electrode fixing plate, and the top of the holed electrode fixing plate is also provided with an electrode fixing clamp.

8. The three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage according to claim 1 is characterized in that: The filter element is filter paper.

9. A three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage according to claim 6, characterized in that: The controller is connected to the solar photovoltaic panel and the storage battery respectively through wires.

10. A three-dimensional electric power system for remediating chromium-contaminated soil based on solar energy storage according to claim 6, characterized in that: The controller, the storage battery and the DC power supply are all arranged below the solar photovoltaic panel and arranged in sequence from top to bottom in the vertical direction.

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