Heavy metal recovery device and recovery method based on anaerobic methanophilic archaea

Abstract

The invention relates to the technical field of heavy metal recovery equipment, and provides a heavy metal recovery device and method based on anaerobic methanophilic archaea, and the heavy metal recovery device based on anaerobic methanophilic archaea comprises an anode chamber, an anode assembly, a cathode chamber and a cathode assembly. The anode chamber is used for accommodating anaerobic methanophilic archaea, electrolyte and methane; the anode assembly is arranged in the anode chamber and is in contact with the anaerobic methanophilic archaea and the electrolyte; the cathode chamber is used for accommodating sewage containing heavy metals and is communicated with the anode chamber; a proton exchange membrane is arranged between the anode chamber and the cathode chamber; and the cathode assembly is arranged in the cathode chamber, is used for being in contact with sewage and is electrically connected with the anode assembly. According to the heavy metal recovery device based on the anaerobic methanophilic archaea, the anode chamber and the cathode chamber are separated through the proton exchange membrane, the anaerobic methanophilic archaea does not need to make direct contact with heavy metal ions, and the influence of the heavy metal ions on the activity of the anaerobic methanophilic archaea can be avoided.

Description

Technical Field

[0001] This invention relates to the field of heavy metal recovery equipment technology, and in particular to a heavy metal recovery device and method based on anaerobic methanogenic archaea. Background Technology

[0002] Existing electrochemical heavy metal recovery devices generally suffer from high energy consumption. Meanwhile, methods using microorganisms to treat wastewater are limited by the toxicity of heavy metals to microorganisms. Specifically, heavy metals in wastewater may disrupt the activity of biological enzymes and ion regulation processes, leading to poor microbial treatment effects and hindering practical application. Summary of the Invention

[0003] This invention provides a heavy metal recovery device and method based on anaerobic methanogenic archaea, which solves the problem in the prior art that the activity of microorganisms is easily affected by heavy metals when treating wastewater containing heavy metals, resulting in poor treatment effect.

[0004] In a first aspect, the present invention provides a heavy metal recovery device based on anaerobic methanophilic archaea, comprising: The anode chamber is used to contain anaerobic methanophilic archaea, electrolyte, and methane. An anode assembly is disposed in the anode chamber and is in contact with the anaerobic methanophilic archaea and the electrolyte; The cathode chamber is used to contain wastewater containing heavy metals and is connected to the anode chamber; a proton exchange membrane is provided between the anode chamber and the cathode chamber; A cathode assembly is disposed in the cathode chamber for contact with the wastewater and is electrically connected to the anode assembly.

[0005] According to the heavy metal recovery device based on anaerobic methanophilic archaea of ​​the present invention, the anode assembly includes: An electrical connector is provided, wherein the anode chamber is provided with a first insertion hole, and the electrical connector passes through the first insertion hole; the first end of the electrical connector extends out of the anode chamber and is electrically connected to the cathode assembly; A hollow fiber tube, the outer wall of which is covered with carbon cloth, the carbon cloth being connected to the second end of the electrical connector.

[0006] The heavy metal recovery device based on anaerobic methanophilic archaea according to the present invention further includes; A methane supply pipeline is provided, wherein the anode chamber is provided with a second insertion hole, the methane supply pipeline passes through the second insertion hole, and the exhaust port of the methane supply pipeline extends into the hollow fiber tube for introducing methane into the hollow fiber tube.

[0007] According to the heavy metal recovery device based on anaerobic methanophilic archaea of ​​the present invention, the cathode chamber comprises: Open-air chamber; A cover plate is detachably mounted to the opening of the open chamber; the cathode assembly is mounted on the side of the cover plate facing the open chamber.

[0008] According to the heavy metal recovery device based on anaerobic methanophilic archaea of ​​the present invention, the cathode assembly comprises: Multiple cathode plates are arranged sequentially at intervals along a first direction. One of two adjacent cathode plates abuts against the first side wall of the open chamber, and the other abuts against the second side wall of the open chamber, to form a reciprocating and meandering sewage flow channel. The first direction is the length direction or the width direction of the open chamber. The open chamber is provided with an inlet and an outlet that are connected to the sewage flow channel.

[0009] According to the heavy metal recovery device based on anaerobic methanophilic archaea of ​​the present invention, a plurality of cathode plates are connected in series.

[0010] The heavy metal recovery device based on anaerobic methanophilic archaea according to the present invention further includes: An electrochemical workstation is electrically connected to both the cathode assembly and the anode assembly, and is used to control the voltage between the cathode assembly and the anode assembly.

[0011] According to the heavy metal recovery device based on anaerobic methanogenic archaea of ​​the present invention, the electrochemical workstation has a reference electrode that extends into the anode chamber and is immersed in the electrolyte.

[0012] Secondly, the present invention also provides a method for recovering heavy metals using an anaerobic methanogenic archaea-based heavy metal recovery device according to any one of the preceding claims, comprising: Sludge containing anaerobic methanogenic archaea and nutrient solution were inoculated in the anode chamber, and methane was introduced into the anode chamber. Wastewater containing heavy metals is introduced into the cathode chamber; Recover heavy metals adhering to the cathode assembly.

[0013] According to the recovery method of the heavy metal recovery device based on anaerobic methanophilic archaea of ​​the present invention, after the step of introducing wastewater containing heavy metals into the cathode chamber, the method further includes: Adjust the cathode voltage according to the type of heavy metal to be recovered.

[0014] The heavy metal recovery device based on anaerobic methanophilic archaea provided by this invention forms a closed loop by sequentially connecting or contacting an anode assembly, a cathode assembly, an electrolyte in the anode chamber, and wastewater in the cathode chamber. Anaerobic methanophilic archaea are inoculated in the anode chamber. The oxidation of methane by these archaea provides electrical energy to the closed loop and provides electrons to the anode assembly. These electrons are transferred through the anode assembly to the cathode assembly to reduce heavy metal ions near the surface of the cathode assembly, causing the heavy metal ions to adhere to the cathode assembly for recovery. The entire process requires no external power supply, resulting in low energy consumption. Furthermore, the anode and cathode chambers are separated by a proton exchange membrane, preventing direct contact between the anaerobic methanophilic archaea and heavy metal ions, thus avoiding the impact of heavy metal ions on the activity of the archaea. This effectively solves the problem in existing technologies where the activity of microorganisms is easily affected by heavy metals when treating wastewater containing heavy metals, leading to poor treatment results. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of a heavy metal recovery device based on anaerobic methanogenic archaea provided in an embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram of the fit between the open chamber and the cathode plate provided in an embodiment of the present invention.

[0018] Figure 3 This is one of the three-dimensional schematic diagrams of a heavy metal recovery device based on anaerobic methanogenic archaea provided in an embodiment of the present invention.

[0019] Figure 4 This is the second three-dimensional schematic diagram of the heavy metal recovery device based on anaerobic methanogenic archaea provided in the embodiments of the present invention.

[0020] Figure 5 This is a schematic flowchart of the heavy metal recovery method based on anaerobic methanogenic archaea provided in this embodiment of the invention.

[0021] Figure label: 1. Anode chamber; 2. Anode assembly; 21. Electrical connectors; 22. Hollow fiber tube; 23. Carbon cloth; 3. Cathode chamber; 31. Open chamber body; 32. Cover plate; 33. Sewage channel; 34. Inlet; 35. Outlet; 4. Cathode assembly; 41. Cathode plate; 5. Proton exchange membrane; 6. Methane supply pipeline; 7. Electrochemical workstation; 71. Reference electrode. Detailed Implementation

[0022] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention.

[0023] The following is combined Figures 1-4 The present invention describes a heavy metal recovery device based on anaerobic methanogenic archaea.

[0024] In some embodiments, such as Figure 1 , Figure 3 and Figure 4 As shown, this invention provides a heavy metal recovery device based on anaerobic methanogenic archaea, comprising: an anode chamber 1, an anode assembly 2, a cathode chamber 3, and a cathode assembly 4. The anode chamber 1 is used to contain anaerobic methanogenic archaea, an electrolyte, and methane; the anode assembly 2 is located in the anode chamber 1 and is in contact with the anaerobic methanogenic archaea and the electrolyte; the cathode chamber 3 is used to contain wastewater containing heavy metals and is connected to the anode chamber 1; a proton exchange membrane 5 is provided between the anode chamber 1 and the cathode chamber 3; the cathode assembly 4 is located in the cathode chamber 3, is in contact with the wastewater, and is electrically connected to the anode assembly 2.

[0025] The anaerobic methanotrophic archaea (ANME) described in this application is a type of archaea capable of oxidizing methane to carbon dioxide under anaerobic conditions via a "reverse methanogenesis" pathway. While oxidizing methane to carbon dioxide, these archaea can transfer the generated electrons to "external acceptors" such as sulfate-reducing bacteria and metal oxides through direct interspecies electron transfer. Anaerobic methanotrophic archaea are typically divided into three main clusters: ANME-1, ANME-2 (containing sub-clusters ANME-2a / b, ANME-2c, and ANME-2d), and ANME-3.

[0026] In this embodiment, by setting up an anode component 2 in the anode chamber 1, introducing anaerobic methanophilic archaea, electrolyte, and methane, and setting up a cathode component 4 in the cathode chamber 3, introducing wastewater containing heavy metals, and electrically connecting the cathode component 4 to the anode component 2, the anode chamber 1 and cathode chamber 3 are interconnected. This allows the heavy metal recovery device based on anaerobic methanophilic archaea in this embodiment to form a fuel cell. While generating electricity using methane, it also reduces heavy metal ions in the wastewater in the cathode chamber 3, so that the reduced heavy metals adhere to the cathode component 4 for recovery.

[0027] In this embodiment, the anode assembly 2, cathode assembly 4, electrolyte in anode chamber 1, and wastewater in cathode chamber 3 can form a closed loop to generate current. Simultaneously, the anaerobic methanophilic archaea in anode chamber 1 can oxidize methane under anaerobic conditions, transferring the electrons generated by methane oxidation extracellularly to anode assembly 2. Anode assembly 2 then transfers these electrons to cathode assembly 4. Cathode assembly 4 comes into contact with wastewater containing heavy metals, where the heavy metal ions are reduced by receiving electrons from the external circuit and adhere to the cathode assembly 4 for easy recovery. Hydrogen ions in the electrolyte of anode chamber 1 can pass through the proton exchange membrane 5 into cathode chamber 3, forming a complete current loop. It is understood that the proton exchange membrane 5 separates anode chamber 1 and cathode chamber 3 in this embodiment, effectively preventing contact between the anaerobic methanophilic archaea and heavy metal ions in the wastewater, thus avoiding impact on the activity of the anaerobic methanophilic archaea.

[0028] The heavy metal recovery device based on anaerobic methanophilic archaea provided by this invention forms a closed loop by sequentially connecting or contacting the anode assembly 2, cathode assembly 4, electrolyte in the anode chamber 1, and wastewater in the cathode chamber 3. Anaerobic methanophilic archaea are inoculated in the anode chamber 1. The oxidation of methane by the anaerobic methanophilic archaea provides electrical energy to the closed loop and provides electrons to the anode assembly 2. These electrons are transferred through the anode assembly 2 to the cathode assembly 4 to reduce heavy metal ions near the surface of the cathode assembly 4, causing the heavy metal ions to adhere to the cathode assembly 4 for recovery. The entire process requires no external power supply, resulting in low energy consumption. Furthermore, the anode chamber 1 and cathode chamber 3 are separated by a proton exchange membrane 5, preventing direct contact between the anaerobic methanophilic archaea and heavy metal ions. This avoids the impact of heavy metal ions on the activity of the anaerobic methanophilic archaea, effectively solving the problem in existing technologies where the activity of microorganisms is easily affected by heavy metals when treating wastewater containing heavy metals, leading to poor treatment results.

[0029] Furthermore, it is understandable that anaerobic methanophilic archaea possess strong substrate adaptability, have low requirements for the quality of methane sources, and can effectively utilize methane in impure biogas for electron transfer.

[0030] Specifically, in some embodiments, such as Figure 1 As shown, the anode assembly 2 includes: an electrical connector 21, a hollow fiber tube 22, and a carbon cloth 23; the anode chamber 1 is provided with a first insertion hole, and the electrical connector 21 passes through the first insertion hole; the first end of the electrical connector 21 extends out of the anode chamber 1 and is electrically connected to the cathode assembly 4; the outer wall of the hollow fiber tube 22 is covered with carbon cloth 23, and the carbon cloth 23 is connected to the second end of the electrical connector 21.

[0031] In this embodiment, the hollow fiber tube 22 and the carbon cloth 23 covering the outer wall of the hollow fiber tube 22 together constitute the electrode that contacts the electrolyte, methane, and anaerobic methanogenic archaea in the anode chamber 1. The hollow fiber tube 22 is a hollow tubular structure, usually made of polymeric materials (such as polysulfone, polypropylene, polytetrafluoroethylene, etc.). The tube wall is covered with micropores, which can provide methane in a bubble-free manner. The methane diffuses evenly to the surface of the carbon cloth 23 through the hollow fiber tube 22, so that the microbial community, mainly composed of anaerobic methanogenic archaea, can form a stable biofilm on the surface of the carbon cloth 23. The anaerobic methanogenic archaea perform anaerobic oxidation of methane on the surface of the biofilm and simultaneously transfer extracellular electrons, transferring the electrons obtained from the oxidation of methane to the carbon cloth 23. The carbon cloth 23 then transfers the electrons to the electrical connector 21. The electrical connector 21 passes through the first socket and is connected to the cathode assembly 4 so as to transfer electrons to the cathode assembly 4. As can be seen from the above, the structure of the hollow fiber tube 22 is conducive to the full contact between the anaerobic methanogenic archaea and the substrate, which can improve the efficiency of the anodic reaction; the carbon cloth 23 wrapped around the outer surface of the hollow fiber tube 22 can promote the enrichment of microorganisms and the electron transfer rate, while also playing a certain protective role for the hollow fiber tube 22, thus comprehensively improving the efficiency of methane conversion and power generation.

[0032] In some embodiments, such as Figure 1 As shown, the heavy metal recovery device based on anaerobic methanophilic archaea also includes: a methane supply pipeline 6, an anode chamber 1 having a second insertion hole, the methane supply pipeline 6 passing through the second insertion hole, and the exhaust port of the methane supply pipeline 6 extending into the hollow fiber tube 22 for introducing methane into the hollow fiber tube 22.

[0033] In this embodiment, by setting up a methane supply pipeline 6, the methane supply pipeline 6 can extend into the anode chamber 1 through the second insertion hole on the anode chamber 1, and the exhaust port of the methane supply pipeline 6 is set in the hollow fiber tube 22, so that methane can be continuously supplied into the hollow fiber tube 22 through the methane supply pipeline 6. The methane diffuses continuously to the surface of the carbon cloth 23 through the micropores inside the hollow fiber tube 22, so as to promote the growth and attachment of the microbial community mainly composed of anaerobic methanophilic archaea on the carbon cloth 23, making the number of anaerobic methanophilic archaea more stable and reliable, which is beneficial to improving the efficiency of the anode reaction.

[0034] In one specific embodiment, such as Figure 1As shown, the anode chamber 1 is a pressure-resistant glass bottle with a height-to-diameter ratio of 1.5:1 and a volume of 210mL. The anode chamber 1 includes a chamber body and a sealing cap. The top of the chamber body has an opening, and the sealing cap is installed at the opening. The sealing cap has a first insertion hole, a second insertion hole, and a third insertion hole. The electrical connector 21 is a carbon rod, which passes through the first insertion hole and is connected to the carbon cloth 23 (hollow fiber tube 22: 8cm high, 3cm diameter; carbon cloth 23: 9.42cm × 8cm) on the surface of the hollow fiber tube 22. The methane supply pipe 6 extends into the chamber body through the second insertion hole, and the exhaust port of the methane supply pipe 6 extends into the hollow fiber tube 22. At the bottom of the hollow fiber tube 22, the inlet of the methane supply line 6 is used to connect to the gas cylinder. The methane supply line 6 is equipped with a pressure reducing valve to regulate the pressure of the gas entering the anode chamber 1. At the same time, the third insertion hole is connected to an exhaust pipe, which is used to detachably connect to the gas bag. It is understood that during the reaction, the anaerobic methanophilic archaea will produce a certain amount of gas. Excess gas in the anode chamber 1 can be discharged into the gas bag through the exhaust pipe to reduce the impact on the gas pressure in the anode chamber 1. After a certain period of reaction, the operator can replace the gas bag.

[0035] In some embodiments, such as Figure 1 and Figure 2 As shown, the cathode chamber 3 includes: an open chamber body 31 and a cover plate 32; the cover plate 32 is detachably installed in the opening of the open chamber body 31; and the cathode assembly 4 is installed on the side of the cover plate 32 facing the open chamber body 31.

[0036] In this embodiment, by detachably connecting the cover plate 32 to the open chamber 31 and installing the cathode assembly 4 on the side of the cover plate 32 facing the open chamber 31, the cover plate 32, when installed on the open chamber 31, can ensure the sealing of the cathode chamber 3 and allow the cathode assembly 4 to contact the sewage inside the open chamber 31. When the operator needs to stop the reaction, the cover plate 32 can be directly removed from the open chamber 31, and the cover plate 32 and the cathode assembly 4 can be taken out together to stop the reaction and collect the heavy metals attached to the cathode assembly 4. The structure is simple and the operation is convenient.

[0037] In some embodiments, such as Figure 1 , Figure 2 and Figure 4 As shown, the cathode assembly 4 includes: a plurality of cathode plates 41, which are arranged sequentially at intervals along a first direction. One of two adjacent cathode plates 41 abuts against the first side wall of the open chamber 31, and the other abuts against the second side wall of the open chamber 31 to form a reciprocating and meandering sewage flow channel 33. The first direction is the length direction or the width direction of the open chamber 31. The open chamber 31 is provided with an inlet 34 and an outlet 35 that communicate with the sewage flow channel 33.

[0038] In this embodiment, multiple cathode plates 41 are arranged at the bottom of the cover plate 32. These cathode plates 41 are arranged parallel to each other along the length or width of the open chamber 31, and adjacent cathode plates 41 are staggered. One cathode plate 41 abuts against the first side wall of the open chamber 31 to form a first gap for sewage flow between the cathode plate 41 and the second side wall of the open chamber 31. The other cathode plate 41 abuts against the second side wall of the open chamber 31 to form a second gap for sewage flow between the other cathode plate 41 and the first side wall of the open chamber 31. This forms an S-shaped, reciprocating sewage flow channel 33 between the multiple cathode plates 41 and the side wall of the open chamber 31. The sewage flow channel 33 is connected to the inlet 34 and the outlet 35 of the open chamber 31. Sewage can enter the open chamber 31 through the inlet 34, flow along the sewage flow channel 33, and then be discharged through the outlet 35. The sewage flow channel 33 can extend the flow path of sewage containing heavy metals, increase the hydraulic residence time, and improve the heavy metal recovery rate.

[0039] In some embodiments, such as Figure 1 and Figure 2 As shown, multiple cathode plates 41 are connected in series. In this embodiment, by connecting multiple parallel cathode plates 41 in series, the current density deviation between the cathode plates 41 can be controlled at a low level, local polarization can be reduced, the uniform reduction of heavy metal ions on the electrode surface can be promoted, and the recovery efficiency can be improved. Specifically, the cathode plates 41 can be connected in series by metal wires.

[0040] In one specific embodiment, such as Figure 1 As shown, the cathode chamber 3 (including the open chamber body 31 and the cover plate 32) is a corrosion-resistant glass box, 30cm long, 19cm wide, and 12cm high. The inlet 34 and outlet 35 of the open chamber body 31 are diagonally arranged. Multiple cathode plates 41 are staggered and spaced along the width of the open chamber body 31 between the inlet 34 and outlet 35. The spacing between adjacent cathode plates 41 is 2.5cm. The bottom edge of the cathode plate 41 is tightly fitted to the bottom wall of the open chamber body 31, one side edge of the cathode plate 41 is tightly fitted to one side wall of the open chamber body 31, and a 3cm wide gap is left between the other side edge and the other side wall of the open chamber body 31 to allow sewage to pass through. The inlet 34 is connected to the inlet pipe, and the outlet 35 is connected to the outlet pipe. Both the inlet and outlet pipes are equipped with control valves to control the sewage flow rate, so as to continuously supply and drain water to the sewage channel 33.

[0041] Specifically, the cathode plate 41 can be a platinum plate.

[0042] Specifically, in some embodiments, the anode chamber 1 is provided with a first connecting pipe and the cathode chamber 3 is provided with a second connecting pipe; rubber gaskets are provided at the port positions of the first connecting pipe and the second connecting pipe, the first connecting pipe and the second connecting pipe are connected to each other, and the proton exchange membrane 5 is sandwiched between the two rubber gaskets.

[0043] In some embodiments, such as Figure 1 , Figure 3 and Figure 4 As shown, the heavy metal recovery device based on anaerobic methanogenic archaea also includes: an electrochemical workstation 7, which is electrically connected to the cathode assembly 4 and the anode assembly 2 respectively, and is used to control the voltage between the cathode assembly 4 and the anode assembly 2.

[0044] In this embodiment, by setting an electrochemical workstation 7 between the cathode assembly 4 and the anode assembly 2, the electrochemical workstation 7 can transfer electrons between the cathode assembly 4 and the anode assembly 2. Simultaneously, it can apply an adjustable bias voltage to the electrodes, thereby enhancing electron transport dynamics, improving reaction rate and selectivity, and achieving effective recovery of various heavy metals. Specifically, the electrochemical workstation 7 can be used to adjust the cathode voltage according to the heavy metal element to be recovered, thereby improving the reduction efficiency of heavy metal ions.

[0045] In some embodiments, such as Figure 1 , Figure 3 and Figure 4 As shown, the electrochemical workstation 7 has a reference electrode 71, which extends into the anode chamber 1 and is immersed in the electrolyte. The electrode potential of the reference electrode 71 is fixed and known, and does not change with the pH value, ion concentration, or other conditions of the solution being measured. In this embodiment, by immersing the reference electrode 71 in the electrolyte of the anode chamber 1, the reference electrode 71 can serve as a potential reference, enabling the electrochemical workstation 7 to detect the anode potential in real time.

[0046] On the other hand, the present invention also provides a recovery method for a heavy metal recovery device based on anaerobic methanogenic archaea provided according to any of the above embodiments. The recovery method of the present invention, by employing the above-described heavy metal recovery device based on anaerobic methanogenic archaea, also possesses the advantages of the aforementioned heavy metal recovery device based on anaerobic methanogenic archaea, which will not be elaborated further here.

[0047] like Figure 5 As shown, the heavy metal recovery method of the anaerobic methanophilic archaea-based heavy metal recovery device of the present invention includes the following steps: Step S101: Inoculate the anode chamber with sludge containing anaerobic methanogenic archaea and nutrient solution, and introduce methane into the anode chamber.

[0048] Step S102: Introduce wastewater containing heavy metals into the cathode chamber.

[0049] Step S103: Recover heavy metals adhering to the cathode assembly.

[0050] Before treating the wastewater, a nutrient solution and sludge containing enriched anaerobic methanogenic archaea need to be added to the anode chamber 1. It is understood that, by appropriately setting the composition of the nutrient solution, it can also serve as an electrolyte. In one specific embodiment, the nutrient solution comprises: 0.1 g / L CaCl2·2H2O, 0.1 g / L MgCl2·4H2O, 0.05 g / L KH2PO4, 0.5 g / L NH4Cl, 2.38 g / L HEPES (4-hydroxyethylpiperazine ethanesulfonic acid), and a 2 mL / L stock solution containing trace elements such as iron, copper, nickel, and cobalt. The pH of the nutrient solution is 7.25.

[0051] Next, methane or methane-containing biogas can be introduced into the anode assembly 2 through the methane supply pipe 6. Specifically, methane can be introduced into the hollow fiber tube 22 near the bottom through the methane supply pipe 6. The methane diffuses evenly through the micropores on the tube wall to the carbon cloth 23 on the outer surface of the hollow fiber tube 22, so that the microbial community, mainly composed of anaerobic methanophilic archaea, forms a stable biofilm on the surface of the carbon cloth 23. The anaerobic methanophilic archaea perform anaerobic oxidation of methane on the surface of the biofilm and at the same time carry out an extracellular electron transfer mechanism to transfer electrons to the carbon cloth 23. The carbon cloth 23 is then transferred to the cathode assembly 4 through the electrical connector 21 and the electrochemical workstation 7.

[0052] At the same time, wastewater containing heavy metals to be treated needs to be introduced into the cathode chamber 3. The wastewater comes into contact with the cathode plate 41, and the heavy metal ions in the wastewater are reduced by electrons transferred by the external circuit on the surface of the cathode plate 41. The reduced heavy metals adhere to the cathode plate 41.

[0053] After a reaction period, the cathode assembly 4 can be removed from the cathode chamber 3 to collect the heavy metals adhering to the cathode plate 41. For example, the cover plate 32 of the cathode chamber 3 can be removed from the open chamber body 31, and the cathode plate 41 can be carried out through the cover plate 32 to uniformly purify and recover the heavy metals adhering to the cathode plate 41.

[0054] The heavy metal recovery device and method based on anaerobic methanophilic archaea of ​​the present invention can be used to treat Cr-containing... 6 + Sb 5+ Cu 2+ Ni 2+ Zn 2+ Cd 2+ Se 6+ Se 4+ Wastewater containing heavy metal ions is particularly suitable for heavy metals that are easily precipitated after reduction.

[0055] Furthermore, in some embodiments, after step S102: introducing wastewater containing heavy metals into the cathode chamber, the following steps are also included: Adjust the cathode voltage according to the type of heavy metal to be recovered.

[0056] In wastewater treatment, the cathode voltage can be adjusted via the electrochemical workstation 7 according to the types of heavy metals that need to be recovered. Reasonable adjustment of the cathode voltage can improve the recovery efficiency of the cathode assembly 4 for specific types of heavy metals. For example, the voltage can be determined through preliminary experiments, such as for Cu... 2+ During reduction and recovery, the cathode voltage can be adjusted to 0.3-0.5V using electrochemical workstation 7; for Cr... 6+ During reduction and recovery, the cathode voltage can be adjusted to 1.2-1.5V.

[0057] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heavy metal recovery device based on anaerobic methanogenic archaea, characterized in that, include: The anode chamber is used to contain anaerobic methanophilic archaea, electrolyte, and methane. An anode assembly is disposed in the anode chamber and is in contact with the anaerobic methanophilic archaea and the electrolyte; The cathode chamber is used to contain wastewater containing heavy metals and is connected to the anode chamber; a proton exchange membrane is provided between the anode chamber and the cathode chamber; A cathode assembly is disposed in the cathode chamber for contact with the wastewater and is electrically connected to the anode assembly.

2. The heavy metal recovery device based on anaerobic methanogenic archaea according to claim 1, characterized in that, The anode assembly includes: An electrical connector is provided, wherein the anode chamber is provided with a first insertion hole, and the electrical connector passes through the first insertion hole; the first end of the electrical connector extends out of the anode chamber and is electrically connected to the cathode assembly; A hollow fiber tube, the outer wall of which is covered with carbon cloth, the carbon cloth being connected to the second end of the electrical connector.

3. The heavy metal recovery device based on anaerobic methanogenic archaea according to claim 2, characterized in that, Also includes; A methane supply pipeline is provided, wherein the anode chamber is provided with a second insertion hole, the methane supply pipeline passes through the second insertion hole, and the exhaust port of the methane supply pipeline extends into the hollow fiber tube for introducing methane into the hollow fiber tube.

4. The heavy metal recovery device based on anaerobic methanogenic archaea according to claim 1, characterized in that, The cathode chamber includes: Open-air chamber; A cover plate is detachably mounted to the opening of the open chamber; the cathode assembly is mounted on the side of the cover plate facing the open chamber.

5. The heavy metal recovery device based on anaerobic methanogenic archaea according to claim 4, characterized in that, The cathode assembly includes: Multiple cathode plates are arranged sequentially at intervals along a first direction. One of two adjacent cathode plates abuts against the first side wall of the open chamber, and the other abuts against the second side wall of the open chamber, to form a reciprocating and meandering sewage flow channel. The first direction is the length direction or the width direction of the open chamber. The open chamber is provided with an inlet and an outlet that are connected to the sewage flow channel.

6. The heavy metal recovery device based on anaerobic methanophilic archaea according to claim 5, characterized in that, Multiple cathode plates are connected in series.

7. The heavy metal recovery device based on anaerobic methanogenic archaea according to claim 1, characterized in that, Also includes: An electrochemical workstation is electrically connected to both the cathode assembly and the anode assembly, and is used to control the voltage between the cathode assembly and the anode assembly.

8. The heavy metal recovery device based on anaerobic methanogenic archaea according to claim 7, characterized in that, The electrochemical workstation has a reference electrode that extends into the anode chamber and is immersed in the electrolyte.

9. A method for recovering heavy metals using an anaerobic methanogenic archaea-based heavy metal recovery device according to any one of claims 1-8, characterized in that, include: Sludge containing anaerobic methanogenic archaea and nutrient solution were inoculated in the anode chamber, and methane was introduced into the anode chamber. Wastewater containing heavy metals is introduced into the cathode chamber; Recover heavy metals adhering to the cathode assembly.

10. The recovery method of the heavy metal recovery device based on anaerobic methanogenic archaea according to claim 9, characterized in that, Following the step of introducing wastewater containing heavy metals into the cathode chamber, the method further includes: Adjust the cathode voltage according to the type of heavy metal to be recovered.

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