Hexavalent chromium reduction, separation and synchronous monitoring device and use method

Abstract

The present application relates to the technical field of groundwater monitoring and treatment, and in particular to a hexavalent chromium reduction, separation, and synchronous monitoring device and a method for use thereof, wherein the device comprises a sleeve-type electrode system and a control system, wherein the sleeve-type electrode system is electrically connected to the control system, and the sleeve-type electrode system is used to adsorb and reduce hexavalent chromium in groundwater, and the control system is used to monitor whether hexavalent chromium is present in groundwater; wherein the sleeve-type electrode system comprises a reference electrode, a well pipe, a cathode assembly, an isolation column, and an anode assembly, and the control system comprises an electrochemical workstation, which is respectively connected to the cathode assembly, the reference electrode, and the anode assembly, and the isolation column is located between the anode assembly and the cathode assembly, and the isolation column has a porous structure and is filled with a conductive material. The present application can promptly detect the contamination concentration of hexavalent chromium in groundwater, improve the hexavalent chromium adsorption efficiency, and can conveniently and quickly identify signals.

Description

Technical Field

[0001] The present application relates to the technical field of groundwater monitoring and treatment, and in particular to a hexavalent chromium reduction separation and synchronous monitoring device and a method of use. Background Art

[0002] Groundwater is one of Earth's most important freshwater resources and a precious resource essential for human survival. In recent years, with the rapid development of Chinese society and the acceleration of urbanization, significant progress has been made in industrial and agricultural production, transportation, and other fields. However, this progress has also brought about environmental pollution problems, particularly the growth of industries such as textiles, chemicals, steel, leather, and electroplating, which has led to the massive generation of chromium slag, dust, and chromium-containing wastewater. These pollutants have caused hexavalent chromium concentrations in groundwater to rise sharply, sometimes reaching 100 mg / L or higher. Hexavalent chromium is not only highly soluble in water but also highly mobile in soil and groundwater, making it recognized internationally as a carcinogenic metal compound.

[0003] Traditional heavy metal monitoring methods, such as chromatography, spectroscopy, and mass spectrometry, require large instruments and are complex to operate, making them unsuitable for real-time, on-site monitoring. Electrochemical methods, such as voltammetric stripping and ion-selective electrodes, require frequent calibration, are expensive per instrument, and have low accuracy when multiple heavy metal ions are present. These methods are unsuitable for network-specific monitoring of hexavalent chromium in groundwater over large, long areas. Therefore, effectively addressing hexavalent chromium contamination in groundwater has become a major challenge in the field of environmental remediation. Summary of the Invention

[0004] In order to improve the adsorption efficiency of hexavalent chromium and reduce economic costs, the present application provides a hexavalent chromium reduction separation and synchronous monitoring device and a method of use.

[0005] In a first aspect, the present application provides a hexavalent chromium reduction separation and synchronous monitoring device, which adopts the following technical solution:

[0006] A hexavalent chromium reduction, separation, and synchronous monitoring device includes a sleeve-type electrode system and a control system, wherein the sleeve-type electrode system is electrically connected to the control system, the sleeve-type electrode system is used to adsorb and reduce hexavalent chromium in groundwater, and the control system is used to monitor whether hexavalent chromium is present in the groundwater;

[0007] In which, the sleeve-type electrode system includes a reference electrode, a well pipe, a cathode assembly, an isolation column and an anode assembly; the control system includes an electrochemical workstation, which is respectively connected to the cathode assembly, the reference electrode and the anode assembly; the isolation column is located between the anode assembly and the cathode assembly, and the isolation column has a porous structure and is filled with conductive material.

[0008] By adopting the above technical solution, voltage is applied to the sleeve electrode system according to the control system, so that the sleeve electrode system reduces the hexavalent chromium in the groundwater and adsorbs it in the anode assembly. Through monitoring by the control system, the pollution concentration of hexavalent chromium in the groundwater can be detected in time, the adsorption efficiency of hexavalent chromium is improved, and the signal can be easily and quickly identified.

[0009] In some embodiments, the telescopic electrode system is 1-6 meters long, and the outer aperture of the telescopic electrode system is 100-300 mm.

[0010] In some embodiments, the anode assembly includes an anode adsorption material, and the anode adsorption material is a conductive material with adsorption capability.

[0011] By adopting this technical solution, the adsorption material in the anode assembly has a large surface area, increasing the area for electron transfer and thus reducing the overpotential. Specifically, when an external voltage is applied, the positive potential of the anode can be effectively reduced, thereby maximizing the negative potential of the cathode. Therefore, this technology only requires a lower applied voltage to reach the potential required for the cathode to reduce hexavalent chromium, thereby reducing the overall operating energy consumption of the equipment.

[0012] In some embodiments, the cathode assembly includes a cathode material, and the cathode material is based on a metal material or stainless steel.

[0013] In a second aspect, the present application provides a method for using a hexavalent chromium reduction separation and synchronous monitoring device, which adopts the following technical solution:

[0014] A method for using a hexavalent chromium reduction, separation, and synchronous monitoring device, based on the hexavalent chromium reduction, separation, and synchronous monitoring device described in the first aspect, comprises the following steps:

[0015] Obtaining a contaminated area and analyzing the location of the contaminated area and the distribution of pollutants to generate a remediation well setting area;

[0016] A repair well is arranged in the repair well setting area, and a corresponding hexavalent chromium reduction separation and synchronous monitoring device is provided in the repair well, and the electrode system includes a cathode assembly and an anode assembly;

[0017] A loaded cathode biofilm is formed based on the cathode material of the cathode assembly, and the cathode biofilm and the anode assembly are subjected to a preset potential based on the control system to reduce and adsorb the hexavalent chromium content in the groundwater.

[0018] By adopting the above technical solution, the regional location corresponding to the polluted area and the distribution of pollutants are analyzed to generate a repair well setting area, and repair wells are arranged in the repair well setting area. The layout density of the repair wells is related to the degree of land pollution. It can be treated accordingly according to the groundwater pollution situation to improve the groundwater drainage efficiency; a cathode biofilm is formed based on the cathode material of the cathode component. The cathode biofilm formed in the cathode component is used to identify and monitor the entry of hexavalent chromium and can judge the hexavalent chromium concentration range based on the open circuit potential response. When the anode component adsorbs a certain concentration of hexavalent chromium, the anode component must be replaced in time to improve the hexavalent chromium adsorption efficiency, which can facilitate and quickly identify the signal.

[0019] In some embodiments, the process of forming a cathode biofilm based on the cathode material of the cathode assembly includes the following steps:

[0020] Using the electrode material in the cathode assembly as an anode, applying a first preset potential and running for a first preset time to obtain an anode biofilm;

[0021] A second preset potential is applied to the anode biofilm, and the bioanode is reversed and operated for a second preset time to obtain a cathode biofilm.

[0022] By adopting the above technical solution, in situ inversion cultivation of cathode biofilm can improve energy utilization efficiency, promote biofilm formation, improve biofilm stability, and reduce hexavalent chromium in groundwater based on the cathode biofilm to obtain trivalent chromium, which facilitates the adsorption of trivalent chromium by the anode component, thereby improving the reduction and adsorption efficiency of hexavalent chromium in groundwater.

[0023] In some embodiments, the cathode assembly includes a cathode material, and before forming the cathode biofilm based on the cathode material of the cathode assembly, the following steps are further included:

[0024] placing the cathode material in acetone, ethanol, and deionized water for ultrasonic cleaning for a third preset time to obtain a preliminary clean material;

[0025] placing the preliminary cleaned material in a tube furnace and treating it in a first preset reducing atmosphere to obtain a first reduced material;

[0026] treating the first reducing material in a second preset reducing atmosphere to obtain a second reducing material;

[0027] placing the second reducing material in pure helium and cooling it to room temperature to achieve carbon coating modification on the surface of the cathode material;

[0028] The ratio of hydrogen to helium in the first preset reducing atmosphere is 3:1.

[0029] By adopting the above technical solution, the surface of the cathode material is modified with a carbon coating, which can serve as a buffer layer to reduce the iron catalytic effect and avoid the formation of amorphous carbon.

[0030] In some embodiments, the first reducing material is treated in a second preset reducing atmosphere to obtain a second reducing material, wherein the method for generating the second reducing material includes the following steps:

[0031] placing the first reducing material in a mixed gas of hydrogen, helium, and methane at a first preset temperature, and growing the first reducing material in a second preset reducing atmosphere for a fourth preset time;

[0032] Among them, the ratio of hydrogen, helium and methane in the second preset reducing atmosphere is 1:4:1.

[0033] In some embodiments, the control system includes an electronic monitoring display, and after the control system powers on the telescopic electrode system, the control system includes the following steps:

[0034] Regularly obtaining an open circuit absolute value, and determining whether the open circuit absolute value is lower than a preset value;

[0035] If the open circuit absolute value is lower than the preset value, a toxicity pollution signal is generated, and the adsorption quantity is obtained based on the toxicity pollution signal;

[0036] Comparing the adsorption quantity with a preset quantity, and determining whether the adsorption data exceeds the preset quantity;

[0037] If the adsorption quantity exceeds the preset quantity, a filler replacement signal is generated and sent to the electronic monitoring display.

[0038] By adopting the above technical solution, the open circuit absolute value is obtained regularly, and the open circuit absolute value is compared with the preset value. If the open circuit absolute value is lower than the preset value, a toxic pollution signal is generated, which can timely monitor whether there is toxic pollution of hexavalent chromium in the groundwater. When it is determined that there is toxic pollution of hexavalent chromium in the groundwater, the adsorption quantity is obtained based on the toxic pollution signal; the adsorption quantity is compared with the preset quantity, and it is determined whether the adsorption data exceeds the preset quantity; if the adsorption quantity exceeds the preset quantity, a filler replacement signal is generated, and the filler replacement signal is sent to the electronic monitoring display, so that the staff can replace the anode assembly without the need to reinstall the device, thereby reducing economic costs.

[0039] In some embodiments, the determining whether the open circuit absolute value is lower than a preset value, the preset value being 20% ​​to 50% of the absolute value of the potential, wherein the method for obtaining the absolute value of the potential comprises the following steps:

[0040] The sleeve electrode system is energized in a preset energizing mode, and an open circuit potential signal generated by the biological cathode is obtained, and the absolute value of the potential is obtained according to the open circuit potential signal.

[0041] In summary, this application includes at least one of the following beneficial technical effects:

[0042] 1. Voltage is applied to the sleeve electrode system according to the control system, so that the sleeve electrode system reduces the hexavalent chromium in the groundwater and adsorbs it in the anode assembly. Through the monitoring of the control system, the amount of hexavalent chromium pollution in the groundwater can be discovered in time, so that the anode assembly can be replaced in time, the adsorption efficiency of hexavalent chromium can be improved, and the economic cost can be reduced;

[0043] 2. Open circuit potential is used to monitor hexavalent chromium concentration because it provides a real-time method for monitoring changes in pollutant concentrations. When pollutant concentrations change, the open circuit potential can respond quickly. Changes in the open circuit potential can also reflect the activity state of the cathode biofilm, thereby assessing the toxic effects of pollutants on the biofilm.

[0044] 3. When the hexavalent chromium adsorption value reaches the preset number, the anode adsorption material needs to be replaced in time. If the adsorbent is used for a long time, its structure or active sites will change, resulting in a decrease in adsorption, and pollutants will re-enter the water body, reducing the treatment efficiency. Frequent replacement can ensure adsorption efficiency, but it will also increase treatment costs and operational complexity. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] Figure 1 Schematic diagram of the structure of the hexavalent chromium reduction separation and synchronous monitoring device provided in an embodiment of the present application;

[0046] Figure 2 This is a flowchart of the method for using the device provided in the embodiment of the present application;

[0047] Figure 3 This is a schematic diagram of the structure of an electronic device provided in an embodiment of the present application;

[0048] Figure 4 This is a flowchart of the steps of the monitoring method provided in the embodiment of the present application.

[0049] Explanation of the accompanying symbols: 10. Electronic monitoring display; 20. Electrochemical workstation; 31. Reference electrode; 32. Well pipe; 33. Cathode assembly; 34. Isolation column; 35. Anode assembly; 40. Microorganism; 51. Processor; 52. Memory; 53. Computer program. DETAILED DESCRIPTION

[0050] In order to more clearly understand the purpose, technical solutions and advantages of the present application, the present application is described and illustrated below in conjunction with the accompanying drawings and embodiments. However, it should be understood by those skilled in the art that the present application can be implemented without these details. In some cases, in order to avoid unnecessary descriptions that make various aspects of the present application obscure, the well-known methods, processes, systems, components and / or circuits that have been described at a higher level will not be described in detail. It is obvious to those skilled in the art that various changes can be made to the embodiments disclosed in the present application, and the general principles defined in the present application can be applied to other embodiments and application scenarios without departing from the principles and scope of the present application. Therefore, the present application is not limited to the embodiments shown, but conforms to the broadest scope consistent with the scope claimed for protection in the present application.

[0051] The embodiments of the present application disclose a hexavalent chromium reduction separation and synchronous monitoring device.

[0052] like Figure 1 As shown, a hexavalent chromium reduction, separation and synchronous monitoring device includes a sleeve electrode system and a control system. The sleeve electrode system is electrically connected to the control system. The sleeve electrode system is used to adsorb and reduce hexavalent chromium in groundwater, and the control system is used to monitor whether hexavalent chromium exists in groundwater.

[0053] Among them, the sleeve electrode system includes a reference electrode 31, a well pipe 32, a cathode assembly 33, an isolation column 34 and an anode assembly 35, and the control system includes an electronic monitoring display 10 and an electrochemical workstation 20. The electronic monitoring display 10 is electrically connected to the electrochemical workstation 20, and the electrochemical workstation 20 has three connection holes, which are respectively connected to the reference electrode 31, the anode assembly 35 and the electrode materials in the cathode assembly 33.

[0054] Specifically, since hexavalent chromium contamination in groundwater is generally within a range of 3 to 5 meters, the sleeve electrode system is designed to be 1 to 6 meters long. Since a too small aperture will lead to a reduction in the reduction and adsorption functions, and a too large aperture will lead to excessively high construction costs, the outer aperture of the sleeve electrode system is set to 100 to 300 mm in this embodiment.

[0055] The main function of the reference electrode 31 is to provide a stable potential reference. The well pipe 32 has toughness and corrosion resistance and is made of one or more of PVC and PE materials. The well pipe 32 is filled with one or more of sand, quartz, and cement to provide support.

[0056] The cathode assembly 33 includes a cathode material, which is based on a metal material or stainless steel. Since the metal material has good electrical conductivity and the microorganism 40 has a surface adhesion effect, and the stainless steel material has good corrosion resistance, the use of conductive polymers, nanomaterials, and electrochemical corrosion to modify its surface can improve its microorganism 40 loading capacity.

[0057] Separator 34 is located between anode assembly 35 and cathode assembly 33. Separator 34 has a uniformly distributed porous structure, providing water permeability. Separator 34 is porous and filled with a conductive material, separating anode assembly 35 from cathode assembly 33 to form an anode reaction chamber and a cathode reaction chamber. The anode assembly is located in the anode reaction chamber, while the cathode assembly is located in the cathode reaction chamber. The conductive material may include, but is not limited to, one or more of metal powder, carbon black filler, and chitosan.

[0058] Anode assembly 35 includes an anode adsorption material, which is a conductive material with adsorption capacity. The anode material is selected from one or more of metal-organic framework (MOF) materials, activated carbon, and adsorption polymers. MOF materials have high specific surface area, abundant active sites, and are easily chemically modified. Activated carbon is corrosion-resistant, has a high specific surface area, and is low-cost. Adsorption polymers have high porosity and abundant functional groups, providing multiple interactions during the adsorption process.

[0059] In addition, the effective range radius of the sleeve-type electrode system in polluted areas is 1 to 2 meters, and the spacing is 2 to 4 meters. Although too small a spacing can improve the accuracy of the data, it may lead to increased monitoring costs. Too large a spacing may not accurately reflect the distribution of pollutants and may cause the pollution source to not be covered within the monitoring range, making it impossible to detect and deal with pollution problems in a timely manner.

[0060] In another embodiment, the present application also discloses a method for using a hexavalent chromium reduction separation and synchronous monitoring device.

[0061] Reference Figure 2 The method for using the hexavalent chromium reduction separation and synchronous monitoring device is based on the hexavalent chromium reduction separation and synchronous monitoring device provided in the above embodiment, comprising the following steps:

[0062] S100: Obtain a polluted area, and analyze the polluted area according to its corresponding regional location and pollutant distribution to generate a repair well setting area.

[0063] S200: A repair well is arranged in the repair well setting area, and a corresponding hexavalent chromium reduction separation and synchronous monitoring device is installed in the repair well.

[0064] S300, forming a loaded cathode biofilm based on the cathode material of the cathode assembly, and subjecting the cathode biofilm and the anode assembly to a preset potential based on a control system to reduce and adsorb the hexavalent chromium content in the groundwater.

[0065] Among them, the contaminated area represents the area contaminated by hexavalent chromium, the repair well setting area represents the area where the repair well is set, and the electrochemical workstation 20 in the control system energizes the electrode material in the cathode assembly 33 to generate a cathode biofilm in the repair well, which is convenient for the subsequent reduction of hexavalent chromium in the groundwater, and then the anode assembly 35 is used to adsorb the reduced hexavalent chromium to complete the reduction and adsorption of hexavalent chromium in the groundwater. The preset potential mentioned here is -0.8~-0.4V, which is set based on the reference electrode 31. The electrode system includes a cathode assembly and an anode assembly.

[0066] The control system further includes electronic equipment, which includes a memory 52 and a processor 51 coupled to each other. The memory 52 stores a computer program 53 that can be executed on the processor 51. When the computer program 53 is executed by the processor 51, the method for using the hexavalent chromium reduction separation and synchronous monitoring device is implemented.

[0067] Reference Figure 1 and Figure 3 The processor 51 may be a central processing unit 51, a general purpose processor 51, a digital signal processor 51, an application specific integrated circuit, a field programmable gate array or other programmable logic device, a transistor logic device, a hardware component or any combination thereof, and is used to run program codes stored in the memory 52 or process data.

[0068] The memory 52 may be a ROM or other type of static storage device capable of storing static information and instructions, a random access memory 52 or other type of dynamic storage device capable of storing information and instructions, an electrically erasable programmable read-only memory 52, a read-only optical disc or other optical disc storage, an optical disc storage (including a compact disc, laser disc, optical disc, digital versatile disc, Blu-ray disc, etc.), a magnetic disk storage medium or other magnetic storage device, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer, but is not limited thereto. In some embodiments, the memory 52 may be an internal storage unit.

[0069] The processor 51 and the memory 52 are connected via a bus. The bus may include a path for transmitting information between the above components. The bus may be a peripheral component interconnect standard bus or an extended industry standard architecture bus. The bus may be divided into an address bus, a data bus, a control bus, etc. For ease of representation, Figure 3 Only one thick line is used in the diagram, but this does not mean that there is only one bus or one type of bus.

[0070] Specifically, the processor 51 evenly arranges repair wells according to the location and shape of the land in the contaminated area and the distribution of pollutants in the land, arranges a sleeve-type electrode system in the repair wells, adds microbial liquid 40 to the cathode reaction chamber, and the electricity-producing microorganisms 40 include but are not limited to one or more of the genera Geobacter, Shewanella and Pseudomonas. Then, a cathode biofilm is generated based on the cathode assembly 33 and the control system, and the cathode biofilm and the anode assembly 35 are subjected to a preset potential based on the control system to reduce and adsorb the hexavalent chromium content in the groundwater.

[0071] It should be noted here that the layout of remediation wells includes but is not limited to the plum blossom-shaped layout method or the chessboard-shaped layout method. These methods are representative and evenly distributed to ensure the accuracy and reliability of the monitoring data. The specific layout should be determined based on the specific location distribution of the contaminated site.

[0072] In addition, the 40 electrogenic microorganisms belong to the genera Geobacter, Shewanella and Pseudomonas. These 40 electrogenic microorganisms have efficient electron transfer capabilities, can convert chemical energy into electrical energy and can adapt to different environmental conditions, such as different temperatures, electric fields, pressures, salinity and pH.

[0073] In another embodiment, forming a cathode biofilm based on the cathode material of the cathode assembly comprises the following steps:

[0074] The electrode material in the cathode assembly 33 is used as the anode, a first preset potential is applied and the process is run for a first preset time to obtain an anode biofilm.

[0075] A second preset potential is applied to the anode biofilm, and the bioanode is reversed and operated for a second preset time to obtain a cathode biofilm.

[0076] The first preset potential includes a potential of -0.2 to 0.2 V, and the first preset time includes 3 to 7 days. The second preset potential includes a potential of -0.8 to -0.4 V, and the second preset time includes 2 to 3 days. The first preset potential and the second preset potential mentioned here are both based on the reference electrode 31.

[0077] Specifically, after adding one or more of the microorganisms 40 of the genus Geobacter, Shewanella, and Pseudomonas to the cathode assembly 33, a potential of -0.2 to 0.2 V is applied and the process is stably operated for 3 to 7 days to cultivate the anode biofilm.

[0078] In the cathode assembly 33, the cathode is reversed in situ to culture the cathode biofilm, and the applied potential is adjusted to -0.8~-0.4V to perform bioanode reversal to culture the cathode biofilm. The process is stable for 2~3 days until the current is stable, and the cathode biofilm culture is considered complete.

[0079] It should be noted here that in situ inversion cultivation of cathode biofilm can improve energy utilization efficiency, promote biofilm formation, and improve biofilm stability. In situ inversion in the cathode assembly 33 refers to the abnormal reversal of the function or polarity of the cathode during operation, causing it to change from an electron acceptor to an electron donor, or the electric potential behavior is opposite to the design. The specific reversal process is a prior art and will not be described in detail here. Bioanode reversal generally refers to the phenomenon that the electrode potential of the anode in a microbial 40 fuel cell or similar bioelectrochemical system is abnormally offset, causing its potential to be higher than that of the cathode. The specific operation is a routine operation and will not be described in detail here.

[0080] In another embodiment, the cathode assembly 33 includes a cathode material, and before forming the cathode biofilm based on the cathode material of the cathode assembly, the following steps are further included:

[0081] The cathode material is placed in acetone, ethanol, and deionized water for ultrasonic cleaning for a third preset time to obtain a preliminary clean material.

[0082] The preliminary cleaned material is placed in a tube furnace and treated in a first preset reducing atmosphere to obtain a first reduced material.

[0083] The first reduced material is treated in a second preset reducing atmosphere to obtain a second reduced material.

[0084] The second reducing material is placed in pure helium and cooled to room temperature to achieve carbon coating modification on the surface of the cathode material.

[0085] The third preset time includes 30 minutes, and the first reduced material is a material generated by being treated in the first preset reducing atmosphere. The specific method for obtaining the material includes the following steps:

[0086] The preliminary cleaned material was placed in a tube furnace, and the temperature was raised to 850°C for 50 minutes and kept at this temperature for 10 minutes in a reducing atmosphere with a hydrogen to helium ratio of 3:1 to ensure that the surface of the generated first reduced material electrode was in a reduced state.

[0087] Then, the first reducing material is treated in a second preset reducing atmosphere to obtain a second reducing material. The method for generating the second reducing material includes the following steps.

[0088] The first reducing material is placed in a mixed gas of hydrogen, helium and methane, and the growth temperature is a first preset temperature. The first reducing material is placed in a second preset reducing atmosphere and grown for a fourth preset time. The first preset temperature is 850 degrees and the fourth preset time is 30 minutes.

[0089] Specifically, the mixed gas in the first preset reducing atmosphere is modified to a growth atmosphere with a ratio of hydrogen, helium and methane of 1:4:1, and the growth temperature is 850°C for 30 minutes. Finally, the cathode material electrode is placed in pure helium and cooled to room temperature, that is, the carbon coating modification on the surface of the cathode material electrode is completed.

[0090] Reference Figure 1 and Figure 4 In another embodiment, after the cathode biofilm and the anode assembly 35 are fed into a preset potential based on a control system, the following steps are included:

[0091] S400 , periodically obtaining an open circuit absolute value, and determining whether the open circuit absolute value is lower than a preset value.

[0092] S500 : If the open circuit absolute value is lower than a preset value, a toxicity pollution signal is generated, and the adsorption quantity is obtained based on the toxicity pollution signal.

[0093] S600: Compare the adsorption quantity with a preset quantity and determine whether the adsorption quantity exceeds the preset quantity.

[0094] S700 , if the adsorption quantity exceeds a preset quantity, a filler replacement signal is generated and sent to an electronic monitoring display.

[0095] The open circuit absolute value represents the open circuit potential formed in the bioanode and the biocathode, and the preset value is 20% to 50% of the absolute value of the potential. The method for obtaining the absolute value of the potential includes the following steps:

[0096] The sleeve electrode system is energized in a preset energizing mode, and an open circuit potential signal generated by the biological cathode is obtained, and the absolute value of the potential is obtained according to the open circuit potential signal.

[0097] Specifically, the open circuit potential of the biocathode is around -220mV. The absolute value of the open circuit potential of the biocathode is taken as the absolute value of the potential. When the potential change of the biocathode is subsequently monitored, when the absolute value of the open circuit changes by 20%-50%, that is, when the absolute value of the open circuit changes by 44mv~110mv, it is determined that the groundwater has been contaminated by hexavalent chromium, and a toxic pollution signal is generated.

[0098] For example, an open circuit potential response of 20% to 50% corresponds to the presence of 60 to 300 mg / L of hexavalent chromium in the water body. When the open circuit potential is higher than 50%, it indicates that the hexavalent chromium in the groundwater is greater than 300 mg / L. When the open circuit potential is lower than 20%, it indicates that the concentration is too low or the monitoring is inaccurate.

[0099] The toxicity contamination signal indicates that the hexavalent chromium reduction, separation, and synchronous monitoring device has detected a contamination signal of hexavalent chromium in the groundwater. When the contamination signal is detected, the hexavalent chromium content in the groundwater is calculated based on the toxicity contamination signal. The adsorption amount is then compared with a preset amount to determine whether the adsorption data exceeds the preset amount. If the adsorption amount exceeds the preset amount, a packing replacement signal is generated and sent to the electronic monitoring display 10 so that staff can replace the packing. The adsorption amount is displayed on the electronic monitoring display 10.

[0100] It should be noted here that the preset quantity includes 20~50mg / g, which specifically means that 1g of adsorption filler can absorb 20~50mg of hexavalent chromium. Specifically, by applying a potential of -0.8~-0.4V, the hexavalent chromium concentration in the groundwater is monitored through the electrochemical workstation 20, and the open circuit potential monitoring is performed for 5~10 minutes every 30~60 minutes. The absolute value of the open circuit potential is monitored and recorded. When the absolute value of the open circuit potential is significantly lower than 20%~50% of its average value, hexavalent chromium toxicity pollution is detected. The bioanode adsorption action adsorbs the surrounding hexavalent chromium, and when it flows through the biocathode, it is reduced to trivalent chromium, and then further adsorbed to the anode surface. When the hexavalent chromium adsorption value of the anode adsorption filler reaches 20~50mg / g, the anode adsorption material must be replaced in time, and the replacement desorption treatment must be carried out. For example Figure 1 F1 represents the anode adsorption filler with a hexavalent chromium adsorption value of 20~50 mg / g, while F2 represents the replaced anode adsorption material.

[0101] The implementation principle is:

[0102] First, according to the location and shape of the land in the contaminated area and the distribution of pollutants in the land, remediation wells are evenly arranged, and a sleeve electrode system is arranged in the remediation wells. After adding one or more of 40 microbial species of the genera Geobacter, Shewanella and Pseudomonas to the cathode assembly 33, a -0.2~0.2V potential is applied and the system is operated stably for 3~7 days to cultivate the anode biofilm. The cathode is reversed in situ in the cathode assembly 33 to cultivate the cathode biofilm. The applied potential is adjusted to -0.8~-0.4V, and the bioanode is reversed to cultivate the cathode biofilm. The system is operated stably for 2~3 days until the current is stable, and the cathode biofilm cultivation is considered complete.

[0103] Next, hexavalent chromium concentration in the groundwater was monitored using an electrochemical workstation 20 by applying a potential of -0.8 to -0.4 V. The open circuit potential was monitored for 5 to 10 minutes every 30 to 60 minutes, and the absolute value of the open circuit potential was recorded. Hexavalent chromium toxicity was detected when the absolute value of the open circuit potential was significantly lower than its average value by 20% to 50%. The bioanode adsorbs the surrounding hexavalent chromium, which is then reduced to trivalent chromium when flowing through the biocathode and then further adsorbed onto the anode surface.

[0104] Finally, when the hexavalent chromium adsorption value reaches 20~50mg / g of the anode adsorption filler, the anode adsorption material must be replaced in time and desorbed.

[0105] It should be understood that although the steps in the flowcharts of the accompanying drawings are shown in sequence as indicated by the arrows, these steps are not necessarily performed in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps and they may be performed in other orders.

[0106] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A method for using a hexavalent chromium reduction separation and synchronous monitoring device, the device comprising a sleeve electrode system and a control system, characterized in that: The telescopic electrode system is electrically connected to a control system, the telescopic electrode system is used to adsorb and reduce hexavalent chromium in groundwater, and the control system is used to monitor whether hexavalent chromium exists in groundwater; The sleeve electrode system includes a reference electrode (31), a well pipe (32), a cathode assembly (33), an isolation column (34), and an anode assembly (35); the control system includes an electrochemical workstation (20); the electrochemical workstation (20) is connected to the cathode assembly (33), the reference electrode (31), and the anode assembly (35), respectively; the isolation column (34) is located between the anode assembly (35) and the cathode assembly (33); the isolation column (34) has a porous structure and is filled with one or more of carbon black filler and chitosan; and the control system includes an electronic monitoring display (10); The anode component (35) includes an anode adsorption material, and the anode adsorption material is a conductive material with adsorption capacity, and the anode material is selected from one or more of metal organic framework materials, activated carbon, and adsorption polymers; the cathode component (33) includes a cathode material, and the cathode material is based on a metal material or stainless steel; The method of use includes obtaining a contaminated area and analyzing the location of the contaminated area and the distribution of pollutants to generate a remediation well setting area; arranging a remediation well in the remediation well setting area, wherein a corresponding hexavalent chromium reduction separation and synchronous monitoring device is provided in the remediation well, and the electrode system includes a cathode component (33) and an anode component (35); forming a loaded cathode biofilm based on the cathode material of the cathode component (33), and applying a preset potential to the cathode biofilm and the anode component (35) based on a control system to reduce and adsorb hexavalent chromium in groundwater; After the preset potential is passed into the control system, the following steps are also included: regularly obtaining the open circuit absolute value and judging whether the open circuit absolute value is lower than the preset value; the open circuit absolute value represents the open circuit potential formed in the bioanode and the biocathode; if the open circuit absolute value is lower than the preset value, a toxicity contamination signal is generated, and the adsorption quantity is obtained based on the toxicity contamination signal; the adsorption quantity is compared with the preset quantity, and it is judged whether the adsorption quantity exceeds the preset quantity; if the adsorption quantity exceeds the preset quantity, a filler replacement signal is generated, and the filler replacement signal is sent to the electronic monitoring display (10); judging whether the open circuit absolute value is lower than the preset value, the preset value is 20% to 50% of the potential absolute value, and the method for obtaining the potential absolute value includes the following steps: energizing the sleeve electrode system in a preset power-on mode, and obtaining the open circuit potential signal generated by the biocathode, and obtaining the potential absolute value based on the open circuit potential signal.

2. The method for using the hexavalent chromium reduction separation and synchronous monitoring device according to claim 1, characterized in that: The sleeve-type electrode system is 1 to 6 meters long, and the outer aperture of the sleeve-type electrode system is 100 to 300 millimeters.

3. The method for using the hexavalent chromium reduction separation and synchronous monitoring device according to claim 1, characterized in that: The method of forming a cathode biofilm based on the cathode material of the cathode assembly (33) comprises the following steps: Using the electrode material in the cathode assembly (33) as an anode, applying a first preset potential and running for a first preset time to obtain an anode biofilm; A second preset potential is applied to the anode biofilm, and the bioanode is reversed and operated for a second preset time to obtain a cathode biofilm.

4. The method for using the hexavalent chromium reduction separation and synchronous monitoring device according to claim 1, characterized in that: The cathode component (33) includes a cathode material, and before forming a loaded cathode biofilm based on the cathode material of the cathode component (33), the following steps are also included: placing the cathode material in acetone, ethanol, and deionized water for ultrasonic cleaning for a third preset time to obtain a preliminary clean material; placing the preliminary cleaned material in a tube furnace and treating it in a first preset reducing atmosphere to obtain a first reduced material; treating the first reducing material in a second preset reducing atmosphere to obtain a second reducing material; placing the second reducing material in pure helium and cooling it to room temperature to achieve carbon coating modification on the surface of the cathode material; The ratio of hydrogen to helium in the first preset reducing atmosphere is 3:

1.

5. The method for using the hexavalent chromium reduction separation and synchronous monitoring device according to claim 4, characterized in that: The first reducing material is treated in a second preset reducing atmosphere to obtain a second reducing material, wherein the method for generating the second reducing material includes the following steps: placing the first reducing material in a mixed gas of hydrogen, helium, and methane at a first preset temperature, and growing the first reducing material in a second preset reducing atmosphere for a fourth preset time; Among them, the ratio of hydrogen, helium and methane in the second preset reducing atmosphere is 1:4:1.

Images