An artificial wetland device for treating brackish water with improved electrode layer configuration

Abstract

The present invention discloses an artificial wetland device for treating brackish water with an improved electrode layer configuration, which belongs to the field of artificial wetland treatment devices and includes: a main body, a water inlet is provided at the top of the side wall of the main body, a water outlet is provided at the bottom of the side wall, an anode and a cathode are provided inside the main body, the anode is provided on the side close to the water inlet, the cathode is provided on the side close to the water outlet, and filter material is filled above the anode, between the anode and the cathode, and below the cathode. The present invention improves the dissolved oxygen content in the anode area of the artificial wetland system by using a filter-type electrode to enhance the electrode layer configuration to about 5 mg / L, which is greater than the 0.5-1 mg / L in ordinary submerged flow wetlands, and helps to solve the problem of gradually decreasing dissolved oxygen concentration in artificial wetlands under the action of electric field enhancement; compared with ordinary electrode-enhanced artificial wetland systems, the removal rate of total nitrogen, total phosphorus, COD, and conductivity is increased by 8-15%, and compared with traditional vertical submerged flow artificial wetlands, it is increased by 15-25%.

Description

Technical Field

[0001] The invention belongs to the field of artificial wetland treatment devices, and in particular relates to an artificial wetland brackish water treatment device with an improved electrode layer configuration. Background Art

[0002] In existing electrode-enhanced constructed wetland treatment devices, the conventional electrode layer structure usually uses plate-shaped or columnar electrodes, with anodes and cathodes alternately arranged in the matrix layer. This structure has the following disadvantages:

[0003] 1. Electrode materials are prone to corrosion:

[0004] Commonly used electrode materials such as graphite, copper, and stainless steel are susceptible to corrosion in complex water environments. Corrosion reduces the conductivity of the electrode and can damage the electrode structure, requiring frequent replacement, which increases system maintenance costs.

[0005] 2. Limited effect of microbial attachment:

[0006] Limited surface area: The relatively small surface area of plate and sheet electrodes limits the number and area of attachment of microorganisms, thereby reducing electron transfer efficiency and pollutant degradation rate. Long electron transfer path: After microorganisms attach, electrons need to travel a long path from the microorganisms to the electrode surface, increasing energy loss during the electron transfer process and further reducing the electrode's power generation performance and pollutant removal efficiency.

[0007] 3. Microbial community structure is difficult to control:

[0008] The microbial community structure within constructed wetlands is complex, and the species and number of microorganisms in the electrode layer are difficult to effectively control. Many heterotrophic, non-electrogenic microorganisms consume a lot of energy, reducing the system's power generation performance.

[0009] 4. Uneven arrangement of electrode layers:

[0010] In large constructed wetlands, the distribution of electrodes may be locally dense or sparse, which can lead to uneven electron transfer, resulting in higher microbial activity and pollutant removal efficiency in some areas and lower efficiency in others, resulting in suboptimal overall treatment results.

[0011] 5. The stability of the electrode layer decreases:

[0012] During long-term operation, the electrode layer may shift or deform due to factors such as water erosion, microbial metabolic activity, and chemical corrosion. This will affect the efficiency of electron transfer and microbial attachment, thereby reducing the treatment performance of the constructed wetland.

[0013] 6. High energy consumption:

[0014] To maintain the electrochemical reactions at the electrode layer, a continuous supply of electricity is required, especially when treating high-concentration pollutants. This high energy consumption increases the operating costs of constructed wetlands, reduces their economic viability, and limits their feasibility for large-scale applications. Summary of the Invention

[0015] The object of the present invention is to provide a constructed wetland brackish water treatment device with an improved electrode layer configuration to address the deficiencies in the prior art.

[0016] In order to achieve the above-mentioned object of the invention, the technical solution adopted by the present invention is:

[0017] An artificial wetland device for treating brackish water with an improved electrode layer configuration comprises: a main body, a water inlet is provided at the top end of the side wall of the main body, a water outlet is provided at the bottom end of the side wall, an anode and a cathode are provided inside the main body, the anode is provided on a side close to the water inlet, the cathode is provided on a side close to the water outlet, and filter material is filled above the anode, between the anode and the cathode, and below the cathode.

[0018] Furthermore, the anode includes: two pieces of first foamed nickel mesh, with a sponge mesh sandwiched between the two pieces of the first foamed nickel mesh.

[0019] Furthermore, the first foamed nickel mesh and the sponge mesh are both covered with domesticated salt-tolerant biofilms.

[0020] Furthermore, the pore size of the first foamed nickel mesh is 5-10 ppi.

[0021] Furthermore, the cathode includes: two pieces of second foamed nickel meshes, and manganese sand is sandwiched between the two pieces of the second foamed nickel meshes.

[0022] Furthermore, the pore size of the second foamed nickel mesh is 10-20 ppi.

[0023] Furthermore, the filter material is zeolite, activated carbon or quartz sand.

[0024] The present invention provides an artificial wetland device for treating brackish water with an improved electrode layer configuration, which has the following advantages over the prior art:

[0025] The improved electrode layer configuration of the filter-type electrode enhanced constructed wetland system increases the dissolved oxygen content in the anode area to about 5 mg / L, which is greater than the 0.5-1 mg / L in ordinary subsurface flow wetlands. This helps solve the problem of gradually decreasing dissolved oxygen concentration in constructed wetlands under the action of electric field enhancement.

[0026] Moreover, the system that uses filter-type electrodes and changes the electrode layer configuration increases the removal rate of total nitrogen, total phosphorus, COD, and conductivity by 8-15% compared with the ordinary electrode enhanced artificial wetland system, and increases it by 15-25% compared with the traditional vertical subsurface flow artificial wetland. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are merely embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on the provided drawings without paying any creative work.

[0028] Figure 1 It is a structural schematic diagram of the present invention.

[0029] In the figure: 1-main body, 2-water inlet, 3-water outlet, 4-first foamed nickel mesh, 5-sponge mesh, 6-second foamed nickel mesh, 7-manganese sand. DETAILED DESCRIPTION

[0030] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments:

[0031] refer to Figure 1 As shown, the present invention provides an artificial wetland device for treating brackish water with an improved electrode layer configuration, comprising: a main body 1, a water inlet 2 provided at the top of the side wall of the main body 1, a water outlet 3 provided at the bottom of the side wall, an anode and a cathode provided inside the main body 1, the anode provided on the side close to the water inlet 2, the cathode provided on the side close to the water outlet 3, and filter material filled above the anode, between the anode and cathode, and below the cathode. This device is suitable for conventional mine water and weakly mineralized water, with corresponding mineralizations of less than 1000 mg / L and 1000-3000 mg / L, respectively. The water quality is generally neutral, containing trace metal elements or essentially no toxic or harmful elements.

[0032] As a preferred embodiment, the anode includes: two pieces of first foamed nickel mesh 4 (preferably with a thickness of 1-2 cm), and a sponge mesh 5 (preferably with a thickness of 3 cm) is sandwiched between the two pieces of the first foamed nickel mesh 4. Filling the anode layer with sponge mesh 5 helps to prolong the residence time of dissolved oxygen in the anode layer, while also providing a stable living environment for microorganisms. Using part of the sponge mesh 5 as the anode layer can reduce the need for large nickel mesh and a larger electric field, effectively reducing costs; at the same time, it can also provide a better living carrier for microorganisms, and its ability to adsorb dissolved oxygen is also stronger.

[0033] As a preferred embodiment, the first foamed nickel mesh 4 and the sponge mesh 5 are both covered with a domesticated salt-tolerant biofilm. The microorganisms in the salt-tolerant biofilm can be isolated from the natural environment. For example, salt-tolerant or halophilic microorganisms are isolated from high-salt environments such as seawater, saline-alkali land, and salt lakes, and then cultured and amplified to form a salt-tolerant biofilm. The use of salt-tolerant biofilm technology has many advantages in the treatment of brackish water: 1. The microorganisms therein can remain active in a high-salt environment, effectively degrade pollutants, and have a higher removal load and system stability compared to the activated sludge method. 2. The salt-tolerant biofilm has a tight structure and rich internal protozoa. It can adapt to the impact of high salinity and organic load, increase the turbidity removal rate of brackish water to 61%, make the effluent clearer, and facilitate mud and water separation. 3. The salt-tolerant biofilm can significantly improve the treatment quality of high-salt wastewater, reduce the content of suspended solids and colloids, and reduce the cost of flocculants.

[0034] As a preferred embodiment, the pore size of the first foamed nickel mesh 4 is 5-10 ppi.

[0035] As a preferred embodiment, the cathode comprises: two sheets of second foamed nickel mesh 6 (preferably with a thickness of 1-2 cm), and manganese sand 7 is sandwiched between the two sheets of the second foamed nickel mesh 6. The cathode layer is filled with manganese sand 7 to enhance the redox ability of the reaction device. Manganese hydroxide generated by manganese dioxide and water gaining electrons is an important multi-metal ion adsorbent, and is also a commonly used oxidant and catalyst in chemical reactions. (A. Multi-metal ion adsorbent: Manganese hydroxide can effectively adsorb a variety of heavy metal ions in water, such as copper ions (Cu 2+ ), lead ions (Pb 2+ ), zinc ions (Zn 2+ This adsorption is crucial for purifying water and removing heavy metal contamination. Studies have shown that manganese hydroxide adsorbents prepared through specific synthetic methods have a near-100% removal rate for these heavy metal ions, meeting drinking water standards. B. Oxidant: Manganese dioxide is a strong oxidant. Manganese hydroxide can effectively remove toxic and harmful metal ions from polluted water and oxidatively degrade organic matter such as phenol, 2-propanol, benzene, and printing and dyeing wastewater. Its pollution-removal capabilities are primarily based on surface complexation reactions, surface ion exchange, and the redox effects of variable-valence elements. C. Catalyst: Manganese hydroxide, as a catalyst, can effectively remove organic matter from high-salinity wastewater.

[0036] As a preferred embodiment, the pore size of the second foamed nickel mesh 6 is 10-20 ppi.

[0037] As a preferred embodiment, the filter material is zeolite, activated carbon or quartz sand.

[0038] Due to its loose, porous, and multidimensional structure, nickel foam mesh, when used as an electrode material, provides a larger contact area than conventional electrode plates, allowing for more complete contact between the electric field, water, and microorganisms within it. This results in the loss of electrons at the anode, which reacts with water and produces more oxygen than with conventional electrode plates. This greater contact with microorganisms also increases the efficiency of the electric field enhancement effect.

[0039] The foamed nickel mesh has the characteristics of multi-dimensional and irregular distribution, which will generate different potential differences due to different resistances at different positions, thereby generating weak voltages in different directions in different micropores of the nickel mesh.

[0040] Nickel is a highly conductive metal, with an electrical conductivity of 1.43 × 10^7 S / m. High-quality nickel mesh exhibits excellent conductivity, effectively reducing electrode resistance and evenly distributing current across the electrode surface, thereby increasing the rate of the electrolytic reaction. Nickel mesh exhibits superior conductivity to stainless steel and graphite carbon. Specifically, nickel mesh has the best conductivity, followed by stainless steel, and finally graphite carbon.

[0041] Simulation experiments show that the dissolved oxygen content in the anode area of a constructed wetland system enhanced with a filter-type electrode and improved electrode layer configuration increases to approximately 5 mg / L, exceeding the 0.5-1 mg / L found in conventional subsurface flow wetlands. This helps address the problem of gradually decreasing dissolved oxygen concentration in constructed wetlands due to electric field enhancement. Furthermore, the system using filter-type electrodes and a modified electrode layer configuration increases the removal rates of total nitrogen, total phosphorus, COD, and conductivity by 8-15% compared to conventional electrode-enhanced constructed wetlands, and by 15-25% compared to traditional vertical subsurface flow constructed wetlands.

[0042] In the description of this application, it should be noted that the terms "upper" and "lower" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application. Unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances.

[0043] It should be noted that, in this application, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or device. In the absence of further restrictions, an element defined by the sentence "comprising a ..." does not exclude the presence of other identical elements in the process, method, article or device comprising the element.

[0044] The foregoing is merely a list of specific embodiments of the present application, intended to enable those skilled in the art to understand or implement the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application is not limited to the embodiments shown herein, but is intended to conform to the broadest scope consistent with the principles and novel features of the present application.

Claims

1. A constructed wetland device for treating brackish water with an improved electrode layer configuration, characterized in that: include: A main body (1), wherein a water inlet (2) is provided at the top end of a side wall of the main body (1), and a water outlet (3) is provided at the bottom end of the side wall; an anode and a cathode are provided inside the main body (1); the anode is provided on a side close to the water inlet (2), and the cathode is provided on a side close to the water outlet (3); and filter material is filled above the anode, between the anode and the cathode, and below the cathode; The anode comprises: two sheets of first foamed nickel mesh (4), with a sponge mesh (5) sandwiched between the two sheets of the first foamed nickel mesh (4); The first foamed nickel mesh (4) and the sponge mesh (5) are both covered with a domesticated salt-tolerant biofilm.

2. The artificial wetland device for treating brackish water with an improved electrode layer configuration according to claim 1, characterized in that: The pore size of the first foamed nickel mesh (4) is 5-10 ppi.

3. The constructed wetland device for treating brackish water with an improved electrode layer configuration according to claim 1, characterized in that: The cathode comprises: two pieces of second foamed nickel mesh (6), with manganese sand (7) sandwiched between the two pieces of second foamed nickel mesh (6).

4. The constructed wetland device for treating brackish water with an improved electrode layer configuration according to claim 3, characterized in that: The pore size of the second foamed nickel mesh (6) is 10-20 ppi.

5. The constructed wetland device for treating brackish water with an improved electrode layer configuration according to claim 1, characterized in that: The filter material is zeolite, activated carbon or quartz sand.

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