Anti-clogging biological slow filter device coupled with a microbial fuel cell

Abstract

This invention discloses an anti-clogging biofiltration device coupled with a microbial fuel cell, applied in the field of biofiltration technology. It includes: a biofilter consisting of a porous media coarse filter layer, a cathode region, and an anode region arranged sequentially from top to bottom; a Helmholtz coil array deployed around the biofilter; and an external circuit that, together with the anode and cathode regions, constitutes the microbial fuel cell. The microbial fuel cell provides self-sufficient power to the cathode region, anode region, and Helmholtz coil array for anti-clogging biofiltration. This invention effectively solves the problems of accumulated clogging in EPS (expanded power filters) and the inability to clean the bottom filter media, and realizes self-generated electricity for the microbial fuel cell.

Description

Technical Field

[0001] This invention relates to the field of biofiltration technology, and more specifically to an anti-clogging biofiltration device coupled with a microbial fuel cell. Background Technology

[0002] Biological slow filtration (BSF) is a water treatment process based on the synergistic effect of biofilm (microbial community) on the filter media surface and physical filtration. It purifies wastewater through a triple synergistic mechanism of physical, chemical, and biological action by microorganisms. This technology boasts advantages such as low investment cost, low energy consumption, and simple operation and maintenance, and is widely used in rural decentralized water supply systems. However, during long-term operation, excessive biofilm proliferation and extracellular polymeric substances (EPS) accumulation in BSF systems can lead to irreversible clogging of the filter layer, resulting in problems such as decreased permeability, shortened operating cycles (<3 months), and fluctuations in effluent quality. Therefore, biological clogging is unavoidable in BSF technology.

[0003] Existing mechanical cleaning methods (such as removing surface filter media) can only alleviate surface clogging in the short term and cannot solve the problems of biofilm compaction and pore blockage in the filter media. The main reason is that the dense clogging layer formed by EPS gelation cannot be naturally degraded by microorganisms (the half-life of polysaccharide degradation is >60 days). The secondary reason is that existing anti-clogging technologies (such as mechanical cleaning) disrupt the biofilm ecosystem and cannot be applied to deep filter media. In biological slow filtration (BSF) systems, bioclogging begins with the synergistic accumulation of extracellular polymeric substances (EPS) secreted by microorganisms and inert organic matter (humus, polysaccharides, etc.) in colloidal sludge on the surface of the filter media matrix. This process first forms a viscous layer with high water content and low density. Subsequently, EPS continuously densifies by adsorbing organic / inorganic particles in the wastewater, and finally solidifies into an irreversible clogging layer due to polysaccharide gelation. The fundamental reason is that EPS is mainly composed of large-molecule polysaccharides and proteins, and the natural degradation rate of microorganisms is extremely low (half-life >60 days). Compositional analysis revealed that over 90% of the dry mass of the clogging material was EPS (excessive EPS), with microorganisms accounting for less than 10%. While a suitable amount of EPS can enhance biofilm stability, excessive accumulation will lead to a 30%-50% decrease in matrix porosity. Microscopic observation confirmed that EPS binds organic particles to form a dense membrane structure, significantly accelerating pore shrinkage. Current mainstream physical removal methods (removing the upper filter media) can alleviate surface clogging in the short term, but they cannot address deep biofilm compaction and are prone to causing water quality fluctuations (such as COD fluctuations >20%) during the cleaning process, while also disrupting the continuity of the microbial community.

[0004] Therefore, how to provide an anti-clogging bio-slow filtration device that can effectively solve the problems of EPS accumulation and blockage and the inability to clean the bottom filter material, and realize the self-generated electric drive of microbial fuel cells, is a problem that urgently needs to be solved by those skilled in the art. Summary of the Invention

[0005] In view of this, the present invention provides an anti-clogging biofiltration device coupled with a microbial fuel cell.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A clog-resistant biofiltration device coupled with a microbial fuel cell includes: a biofilter consisting of a porous medium coarse filter layer, a cathode region, and an anode region arranged sequentially from top to bottom; a Helmholtz coil array arranged around the biofilter; and an external circuit that together with the anode region and the cathode region constitutes the microbial fuel cell.

[0008] Microbial fuel cells are used to provide self-sufficient power to the cathode region, anode region, and Helmholtz coil array for bio-slow filtration and anti-clogging.

[0009] Optionally, the surface of the porous media coarse filter layer is also loaded with TiO2 and graphene heterojunction materials to generate active oxygen in the visible light range based on the weak electric field of 0.3-0.5V provided by the microbial fuel cell, and to synergistically degrade recalcitrant organic matter.

[0010] Optional, microbial fuel cells, specifically:

[0011] The anode region is filled with graphene and biochar composite particles and preloaded with electrogenic bacteria to degrade organic matter and generate electricity;

[0012] Electrons are transferred to the cathode region through an external circuit, where they undergo an electrochemical reaction with protons and oxidants that have migrated to the cathode region, forming a closed electrochemical circuit.

[0013] The current is stored in a supercapacitor on an external circuit, forming a microbial fuel cell.

[0014] Optionally, the anode region adopts a biomimetic fractal structure, and the graphene and biochar composite particles filling the anode region are also doped with Fe3O4 particles.

[0015] Optionally, the cathode area is designed as a porous copper foam-based spiral tube embedded in a fine sand layer with a particle size of 0.5-1mm.

[0016] Optionally, an anaerobic barrier layer is added below the cathode region in the anode region;

[0017] The anaerobic partition is filled with a mixture of sulfur and limestone to maintain pH and provide alkalinity for denitrification. Electrogenic bacteria in the upper layer of the anaerobic partition degrade organic matter and generate electricity; electrons are transferred to the cathode area via an external circuit, and some electrons are diverted to the lower layer of the anaerobic partition to reduce NO3. - .

[0018] Optionally, the microbial fuel cell provides self-sufficiency in power to the Helmholtz coil array for bio-slow filtration and anti-clogging purposes, specifically:

[0019] The Helmholtz coil array, powered by the self-sufficient energy provided by the microbial fuel cell, generates a uniform magnetic field in the anode region to promote high-frequency micro-vibration of Fe3O4, thereby maintaining the permeability coefficient of the packing material.

[0020] Optionally, the microbial fuel cell provides self-sufficient power to the anode and cathode regions for bio-slow filtration and anti-clogging purposes, specifically as follows:

[0021] Reduce EPS generation: The anode area forms a reducing environment under the action of a weak electric field of 0.3-0.5V, which inhibits the attachment of aerobic bacteria on the anode; The cathode area, under the action of a weak electric field of 0.3-0.5V, inhibits the excessive proliferation of biofilm, while enhancing the O2 reduction rate, increasing DO to 5-6mg / L, and promoting the metabolism of aerobic nitrifying bacteria.

[0022] Degradation of existing EPS: Under the action of a strong electric field of 1-3V, the anode region generates ·OH through water electrolysis, which electrochemically oxidizes and degrades EPS.

[0023] As can be seen from the above technical solution, compared with the prior art, this invention discloses an anti-clogging biofiltration device coupled with a microbial fuel cell. It effectively solves the problem of EPS accumulation and clogging through a dual electrochemical anti-clogging mechanism based on reducing EPS generation and degrading existing EPS. A magnetic-physical anti-clogging mechanism based on a Helmholtz coil array to generate a magnetic field to promote high-frequency micro-vibration of Fe3O4, maintaining the permeability coefficient of the sulfur packing, is applied to deep filter media, effectively solving the problem of the inability to clean the bottom layer filter media. Through the microbial fuel cell composed of an anode region, a cathode region, and external circuitry, self-generating electricity (100% energy self-sufficiency) is achieved. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of the present 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 only embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the device structure of the present invention.

[0026] In the figure: 1-Porous medium coarse filter layer, 2-Cathode region, 3-Anode region, 4-Helmholtz coil array, 5-External circuit, 6-Supercapacitor, 7-Porous foam copper-based spiral tube, 8-Anaerobic barrier layer. Detailed Implementation

[0027] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0028] Example 1:

[0029] Embodiment 1 of this invention discloses an anti-clogging biofiltration device coupled with a microbial fuel cell, such as... Figure 1 As shown, it includes: a biofilter consisting of a porous medium coarse filter layer 1, a cathode region 2 and an anode region 3 arranged sequentially from top to bottom; a Helmholtz coil array 4 arranged around the biofilter; and an external circuit 5 that together with the anode region 3 and the cathode region 2 constitutes a microbial fuel cell (MFC).

[0030] The surface of the porous medium coarse filter layer 1 is also loaded with TiO2 and graphene heterojunction materials (physical interception + photocatalytic degradation). It can activate the photocatalytic reaction by using the weak current generated by MFC. Under the weak electric field of 0.3-0.5V provided by MFC, TiO2 generates active oxygen (ROS) in the visible light range, which synergistically degrades recalcitrant organic matter (such as antibiotics and dyes) while intercepting large particulate impurities.

[0031] Microbial fuel cells, specifically:

[0032] The anode region 3 is filled with graphene and biochar composite particles (particle size 2-4 mm) and preloaded with electrogenic bacteria (Geobacters pp.) to degrade organic matter and generate electricity;

[0033] Electrons are transferred to cathode region 2 through the external circuit, where they undergo an electrochemical reaction with protons and oxidants that have migrated to cathode region 2, forming a closed electrochemical circuit.

[0034] The current is stored in the supercapacitor 6 on the external circuit 5, forming a microbial fuel cell (100% energy self-sufficiency).

[0035] The anode region 3 adopts a biomimetic fractal structure (such as a root-like nickel mesh), which increases the electrode surface area by 5 times and supports the attachment of multi-layer biofilms; and the graphene and biochar composite particles filling the anode region 3 are also doped with 10% Fe3O4 particles (conductivity > 1000 S / m).

[0036] The cathode region 2 is designed as a porous foam copper-based spiral tube 7 (pore size gradient 3mm→1mm) embedded with a fine sand layer with a particle size of 0.5-1mm, which is beneficial to the transmission and distribution of current.

[0037] Below the cathode region 2, an anaerobic partition layer 8 (10cm) is also provided in the anode region 3;

[0038] Anaerobic layer 8 is filled with a mixture of sulfur and limestone (3:1) to maintain the pH value (7.0-7.5) and provide denitrification alkalinity. The upper layer of anaerobic layer 8 contains geobacter, which degrades organic matter and generates electricity. Electrons are transferred to cathode area 2 via an external circuit, and some electrons are diverted to the lower layer of anaerobic layer where denitrifying bacteria (Pseudomonas) reduce NO3. - This drives heterotrophic / autotrophic denitrification.

[0039] Microbial fuel cells are used to provide self-sufficient power to cathode region 2, anode region 3, and Helmholtz coil array 4 for bio-slow filtration and anti-clogging.

[0040] The microbial fuel cell provides self-sufficiency in power to the Helmholtz coil array 4 for bio-slow filtration and anti-clogging, specifically as follows:

[0041] The Helmholtz coil array 4, powered by the microbial fuel cell, generates a uniform magnetic field of 0.5T in the anode region 3 to promote high-frequency micro-vibration of Fe3O4 (the magnetic field is triggered at 24-hour intervals, with each run lasting 5-10 minutes, stimulating particle movement under non-contact conditions). This prevents the lower layer of the biofiltration material from caking, thereby maintaining the permeability coefficient of the packing material at 10. -3 cm / s.

[0042] The microbial fuel cell provides self-sufficient power to the anode region 3 and the cathode region 2 for bio-slow filtration and anti-clogging, specifically as follows:

[0043] Reduce EPS generation: Under the action of a weak electric field of 0.3-0.5V, the anode zone 3 forms a reducing environment, inhibiting aerobic bacteria from attaching to the anode and reducing EPS generation (EPS production reduced by 40%); Under the action of a weak electric field of 0.3-0.5V, the cathode zone 2 inhibits excessive biofilm proliferation (EPS production ↓40%), while enhancing the O2 reduction rate, increasing DO to 5-6mg / L, promoting the metabolism of aerobic nitrifying bacteria, and improving the degradation capacity of organic matter in the water, thereby reducing the accumulation of organic matter in the gaps between the filter media and reducing the amount of EPS generation from the source;

[0044] Degradation of existing EPS: In the anode zone 3, under the action of a strong electric field of 1-3V every 48 hours, ·OH (hydroxyl radicals) are generated by electrolysis of water to electrochemically oxidize and degrade the EPS (removal rate > 85%), reducing the clogging of the packing material below.

[0045] In addition, cathode region 2 can also disperse the biological blockage EPS between the packing materials in the bio-slow filter under the action of a weak electric field of 0.3-0.5V.

[0046] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on its differences from other embodiments. Similar or identical parts between embodiments can be referred to interchangeably. For the apparatus disclosed in the embodiments, since they correspond to the methods disclosed in the embodiments, the description is relatively simple; relevant parts can be referred to in the method section.

[0047] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. 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 invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A clog-resistant biofiltration device coupled with a microbial fuel cell, characterized in that, include: The biofilter consists of a porous medium coarse filter layer, a cathode region, and an anode region arranged sequentially from top to bottom; a Helmholtz coil array arranged around the biofilter; and an external circuit that together with the anode region and the cathode region constitutes the microbial fuel cell. The microbial fuel cell is used to provide self-sufficient power to the cathode region, anode region and the Helmholtz coil array for bio-slow filtration and anti-clogging. The surface of the porous medium coarse filter layer is also loaded with TiO2 and graphene heterojunction materials, which are used to generate active oxygen in the visible light range based on the weak electric field of 0.3-0.5V provided by the microbial fuel cell, and synergistically degrade recalcitrant organic matter. The microbial fuel cell is specifically: The anode region is filled with graphene and biochar composite particles and preloaded with electrogenic bacteria to degrade organic matter and generate electricity. Electrons are transferred to the cathode region through the external circuit, where they undergo an electrochemical reaction with protons and oxidants that have migrated to the cathode region, forming a closed electrochemical circuit. The current is stored in the supercapacitor in the external circuit, forming the microbial fuel cell; The anode region adopts a biomimetic fractal structure, and the graphene and biochar composite particles filling the anode region are also doped with Fe3O4 particles. The cathode region is designed as a porous copper foam-based spiral tube embedded in a fine sand layer with a particle size of 0.5-1mm; An anaerobic barrier layer is also provided below the cathode region in the anode region; The anaerobic interlayer is filled with sulfur and limestone mixed filler, which is used for maintaining PH value and providing denitrification alkalinity; the upper layer of the anaerobic interlayer produces electricity by degrading organic matters, and the electrons are transmitted to the cathode area through the external circuit, and part of the electrons are shunted to the lower layer of the anaerobic interlayer to reduce NO3 - ; The microbial fuel cell provides self-sufficient power to the Helmholtz coil array for bio-slow filtration and anti-clogging, specifically as follows: The Helmholtz coil array, based on the self-sufficient power provided by the microbial fuel cell, generates a uniform magnetic field in the anode region to promote high-frequency micro-vibration of Fe3O4, thereby maintaining the permeability coefficient of the packing material. The microbial fuel cell provides self-sufficient power to the anode and cathode regions for slow biofiltration and anti-clogging purposes, specifically as follows: Reduce EPS generation: The anode area forms a reducing environment under the action of a weak electric field of 0.3-0.5V, which inhibits the attachment of aerobic bacteria on the anode; The cathode area, under the action of a weak electric field of 0.3-0.5V, inhibits the excessive proliferation of biofilm, while enhancing the O2 reduction rate, increasing DO to 5-6mg / L, and promoting the metabolism of aerobic nitrifying bacteria. Degradation of existing EPS: The anode region generates EPS through water electrolysis under a strong electric field of 1-3V. OH is used to electrochemically oxidize and degrade EPS.

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