A polyazo dye wastewater treatment device and a method of using the same

Abstract

The application discloses a polyazo dye wastewater treatment device and a use method thereof, relates to the fields of power generation technology and degradation of refractory organic matter wastewater, and the device comprises a communicating reactor, a water inlet and a water outlet; a partition plate is arranged in the middle of the communicating reactor; the partition plate divides the communicating reactor into an anode chamber and a cathode chamber; an air cathode is arranged at the top of the cathode chamber, a perforated mesh cage is arranged in the anode chamber, an anode is arranged in the perforated mesh cage, and a region for containing soil containing microorganisms is arranged above the anode; the air cathode and the anode are connected with an external circuit through wires; the water inlet is arranged at the top of the cathode chamber, and the water outlet is arranged at the top of the anode chamber. The application uses soil as an anode matrix, degrades pollutants in wastewater through microorganisms in the soil, is low in cost, simple in operation, and can convert chemical energy of the pollutants in the wastewater into electric energy to compensate for the water treatment cost.

Description

Technical Field

[0001] This invention relates to the fields of environmental engineering power generation technology and treatment of recalcitrant organic wastewater, and in particular to an air cathode-connected, naturally overflowing polyazo dye wastewater treatment device and its usage method. Background Technology

[0002] Polyazo dyes are widely used in dyeing and weaving industries, which generate a large amount of wastewater. If the wastewater is discharged directly without treatment, it will cause environmental pollution. In order to reduce the degree of environmental pollution, it is necessary to treat the polyazo dye wastewater. Therefore, there is an urgent need for a polyazo dye wastewater treatment device. Summary of the Invention

[0003] The purpose of this invention is to provide a polyazo dye wastewater treatment device that can use soil as an anode substrate and degrade pollutants in polyazo dye wastewater through microorganisms in the soil. It is low-cost, simple to operate, and converts the chemical energy of pollutants in wastewater into electrical energy to compensate for water treatment costs.

[0004] To achieve the above objectives, the present invention provides the following solution:

[0005] This invention provides a polyazo dye wastewater treatment device, which includes a connected reactor;

[0006] The interconnected reactor is provided with a support layer, which is used to hold the filling material.

[0007] The interconnected reactor is provided with a partition plate in the middle, and the partition plate is at a set distance from the bottom of the interconnected reactor; the partition plate divides the interconnected reactor into an anode chamber and a cathode chamber;

[0008] An air cathode is provided at the top of the cathode chamber, and a perforated mesh cage is provided in the anode chamber. An anode is provided in the perforated mesh cage, and an area for holding soil containing microorganisms is provided above the anode. The air cathode and the anode are connected to an external circuit through wires.

[0009] The interconnected reactor includes an inlet and an outlet. The inlet is located at the top of the cathode chamber, and the outlet is located at the top of the anode chamber. The inlet is used to introduce a mixed solution of carbon source and polyazo dye wastewater.

[0010] During operation, soil is filled into the area to hold soil containing microorganisms, and filling material is filled into the support layer. The carbon source and polyazo dye wastewater mixed solution enter the cathode chamber through the inlet. The carbon source oxidizes to generate electrons, which are then transferred to the anode via the polyazo dye wastewater solution, soil, and microorganisms. The electrons are then transferred to the air cathode through wires and external circuits to remove pollutants from the water and generate current. The water after removing pollutants overflows from the outlet.

[0011] Optionally, the polyazo dye wastewater treatment device further includes a peristaltic pump, which is connected to the inlet via a water pipe.

[0012] Optionally, the air cathode and the anode are based on graphite felt and wrapped with stainless steel wire mesh.

[0013] Optionally, the anode dimensions are in the range of 1-4cm in length, 1-4cm in width, and 1-4cm in thickness; the air cathode dimensions are in the range of 8-12cm in length, 8-12cm in width, and 1-4cm in thickness.

[0014] Optionally, the external circuit includes an external resistor connected in series with the air cathode and the anode.

[0015] Optionally, the partition panel is an acrylic glass partition panel.

[0016] Optionally, the set distance can be in the range of 1-4cm.

[0017] Optionally, the soil is red soil.

[0018] Optionally, the carbon source is sodium acetate.

[0019] The present invention also provides a method of using the above-mentioned polyazo dye wastewater treatment device, the method comprising:

[0020] Soil is filled into the area above the anode inside the perforated mesh cage to hold the soil containing microorganisms;

[0021] Fill the support layer with filler material;

[0022] A mixed solution of carbon source and polyazo dye wastewater enters the cathode chamber through the inlet. The carbon source oxidizes to generate electrons, which are then transferred to the anode via the polyazo dye wastewater solution, soil, and microorganisms. The electrons are then transferred to the air cathode through wires and external circuits to remove pollutants from the water and generate current. The water after pollutant removal overflows from the outlet.

[0023] According to specific embodiments provided by the present invention, the following technical effects are disclosed: The present invention provides a polyazo dye wastewater treatment device, which includes a connected reactor; a support layer is provided inside the connected reactor for holding filling material; a partition plate is provided in the middle of the connected reactor, and the partition plate is at a set distance from the bottom of the connected reactor; the partition plate divides the connected reactor into an anode chamber and a cathode chamber; an air cathode is provided at the top of the cathode chamber, a perforated mesh cage is provided inside the anode chamber, an anode is provided inside the perforated mesh cage, and a container for holding micro-containing materials is provided above the anode. The invention comprises a soil-containing area for microorganisms; an air cathode and an anode connected to an external circuit via wires; an inlet located at the top of the cathode chamber and an outlet located at the top of the anode chamber; during operation, soil is filled into the area containing the microorganisms, and filling material is added to the support layer; a mixture of carbon source and polyazo dye wastewater enters the cathode chamber through the inlet; the carbon source oxidizes to generate electrons, which are then transferred to the anode via the polyazo dye wastewater solution, soil, and microorganisms, and then to the air cathode via wires and an external circuit to remove pollutants from the water and generate an electric current; the water, after pollutant removal, overflows from the outlet. This invention utilizes soil as the anode matrix, enabling microorganisms in the soil to degrade pollutants in polyazo dye wastewater. It is low-cost, simple to operate, and converts the chemical energy of pollutants in the wastewater into electrical energy to offset water treatment costs, providing a new approach for the sustainable treatment of polyazo dye wastewater. 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 embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0025] Figure 1 This is a schematic diagram of the structure of the polyazo dye wastewater treatment device provided in Embodiment 1 of the present invention;

[0026] Figure 2 The spectral scans of different concentrations of Direct Black BN standard solutions provided in Example 1 of this invention were obtained by scanning with a SHIMADZU UV-2700i instrument.

[0027] Figure 3 The removal rate of direct black BN in water by the SMFC device with southern red soil as the anode matrix provided in Embodiment 1 of the present invention;

[0028] Figure 4 This refers to the power generation voltage of the SMFC device using southern red soil as the anode substrate provided in Embodiment 1 of the present invention;

[0029] Figure 5 The power density curve of the SMFC device with southern red soil as the anode matrix provided in Embodiment 1 of the present invention.

[0030] Symbol explanation:

[0031] 1-Inlet; 2-Air cathode; 3-External resistor; 4-Outlet; 5-Anode; 6-Perforated mesh screen cage; 7-Anode connecting wire; 8-Cathode connecting wire; 9-Partition plate; 10-Gravel; 11-Soil; 12-Data acquisition device. Detailed Implementation

[0032] 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.

[0033] Soil microbial fuel cells (SMFCs) are an emerging technology that utilizes soil-based microbial fuel cells (MFCs). In recent years, they have been used to treat pollutants such as ammonia nitrogen, phosphorus, or COD, while also generating electricity.

[0034] The purpose of this invention is to provide a polyazo dye wastewater treatment device and its usage method, which uses soil as an anode matrix and degrades pollutants in polyazo dye wastewater through microorganisms in the soil. It is low-cost, simple to operate, and converts the chemical energy of pollutants in wastewater into electrical energy to compensate for water treatment costs.

[0035] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0036] like Figure 1 As shown, the present invention provides a polyazo dye wastewater treatment device, which includes a connected reactor.

[0037] The interconnected reactor is equipped with a support layer for holding filling material. The filling material can be gravel, activated carbon, or other materials to ensure uniform water distribution and provide support.

[0038] A partition plate 9 is provided in the middle of the interconnected reactor, and the partition plate 9 is at a set distance from the bottom of the interconnected reactor. The partition plate 9 is located at a certain position above the middle of the interconnected reactor and at a set distance from the bottom of the interconnected reactor. In this embodiment, the partition plate 9 is an plexiglass partition plate, and the set distance ranges from 1 to 4 cm.

[0039] The partition plate 9 divides the interconnected reactor into an anode chamber and a cathode chamber. An air cathode 2 is provided at the top of the cathode chamber. A perforated mesh cage 6 is provided inside the anode chamber. An anode 5 is provided inside the perforated mesh cage 6. An area for holding soil containing microorganisms is provided above the anode 5. The air cathode 2 and the anode 5 are connected to an external circuit through wires.

[0040] like Figure 1 As shown, the interconnected reactor includes an inlet 1 and an outlet 4, which are respectively located at the top of the left and right sides of the interconnected reactor; the inlet 1 is located at the top of the cathode chamber, and the outlet 4 is located at the top of the anode chamber. The inlet is used to introduce a mixed solution of carbon source and polyazo dye wastewater.

[0041] The polyazo dye wastewater treatment unit (SMFC unit) also includes a peristaltic pump, which is connected to the inlet 1 via a water pipe.

[0042] The air cathode 2 and anode 5 are based on pretreated graphite felt, with a stainless steel mesh serving as a current collector wrapped around the outer surface of the graphite felt. Anode 5 is placed at the bottom inside a perforated mesh cage 6. Air cathode 2 is placed at the top of one side of the interconnected reactor. The perforated mesh cage 6 is made of stainless steel. The purpose of placing soil 11 and anode 5 in the perforated mesh cage 6 is to remove the perforated mesh cage 6 from the interconnected reactor to facilitate the replacement of soil 11 and anode 5.

[0043] The pretreatment process for the graphite felt is as follows: the graphite felt is soaked in dilute nitric acid for 2 hours to remove stains on the surface of the graphite felt. After soaking for 2 hours, the graphite felt soaked in dilute nitric acid is rinsed with clean water to obtain the pretreated graphite felt.

[0044] The dimensions of anode 5 are 1-4cm in length, 1-4cm in width, and 1-4cm in thickness; the dimensions of air cathode 2 are 8-12cm in length, 8-12cm in width, and 1-4cm in thickness. The graphite felt of anode 5 is 2.5cm (length) * 2.5cm (width) * 2cm (thickness), while the graphite felt of cathode is 10cm (length) * 10cm (width) * 2cm (thickness).

[0045] like Figure 1 As shown, the external circuit includes an external resistor 3, which is connected in series with the air cathode 2 and the anode 5. The anode 5 and air cathode 2 are led out through the wall of the through-reactor via anode-connecting wire 7 and cathode-connecting wire 8, and connected to the external resistor 3. The data acquisition device 12 is connected in parallel across the external resistor 3 via anode-connecting wire 7 and cathode-connecting wire 8 to form a circuit for voltage data acquisition. Disconnecting the wires from the external resistor 3 creates an open circuit.

[0046] The main body of the polyazo dye wastewater treatment device is an air cathode made of plexiglass and a two-way, naturally overflowing reactor (hereinafter referred to as a connected reactor).

[0047] The carbon source is used as the anode fuel to generate electrons through oxidation. These electrons are then transferred to the anode 5 via a mixture of the carbon source and polyazo dye wastewater, southern red soil, and microorganisms. From there, they are transferred to the air cathode 2 via the anode wire 7, the cathode wire 8, and the external resistor 3, forming a circuit with the internal components of the interconnected reactor to generate current and increase the output power density. Sodium acetate, glucose, etc., can be selected as the carbon source.

[0048] During operation, soil 11 is filled into the area above the anode 5 within the perforated mesh cage 6, which is used to hold soil containing microorganisms. Filling material is then added to the support layer. A mixed solution of carbon source and polyazo dye wastewater is introduced from the top of one side of the device using a peristaltic pump to control the inlet flow rate. The solution enters the cathode chamber through inlet 1, continuously flowing downwards through the cathode area (cathode chamber) to the anode area (anode chamber), and naturally overflows from the top of the anode area. Carbon source oxidation generates electrons, which are transferred to the anode 5 via the polyazo dye wastewater solution, soil 11, and microorganisms. These electrons are then transferred to the air cathode 2 via wires and external circuits to remove pollutants from the water and generate current. The water, after pollutant removal, overflows from outlet 4. In another example, sodium acetate is used as the carbon source, gravel 10 is used as the filling material, and direct black BN is the target pollutant. Southern red soil is used as the anode matrix and placed within the perforated mesh cage 6 to inoculate and start the interconnected reactor. Overflow water is discharged from outlet 4 to maintain water level balance. In this implementation, the red soil specifically selected was from the campus of Jinggangshan University in southern China. Southern red soil contains microorganisms.

[0049] Microorganisms in the southern red soil of the anode region use sodium acetate as fuel to generate electrons, which are transferred to the surface of anode 5, and then to the air cathode 2 through the external circuit and resistor, forming a closed loop to generate current.

[0050] During operation, the temperature of the control system is set at 30±2℃; the influent carbon source is sodium acetate (theoretical COD concentration is 100-400mg / L); the pH of the influent (mixed solution of carbon source and polyazo dye wastewater) is 6.5-7.5; the ammonia nitrogen concentration in the mixed solution is 30-60mg / L; the concentration of Direct Black BN is 0-200mg / L; and the hydraulic retention time is 1-3 days.

[0051] The theoretical total COD (Chemical Oxygen Demand) of the influent wastewater is 300 mg / L. Sodium acetate is used as the co-matrix carbon source. The hydraulic retention time is set to 2.0 days. The plexiglass partition is 2 cm from the bottom of the interconnected reactor and is 1 cm thick. Both the anode and cathode are wrapped with 0.6 mm thick 5-mesh 304 stainless steel wire mesh. Southern red soil that has passed through a 10-mesh sieve is placed inside the stainless steel mesh screen.

[0052] The following experiments were conducted using influent wastewater with different concentrations of direct black BN:

[0053] Part 1: Sodium acetate concentration is 300 mg COD / L, and Direct Black BN concentration is 0 mg / L.

[0054] Part 2: Sodium acetate concentration is 150 mg COD / L, and Direct Black BN concentration is 99.7 mg / L.

[0055] Part 3: Sodium acetate concentration is 0 mg COD / L, and Direct Black BN concentration is 199.5 mg / L.

[0056] The microorganisms carried in the soil multiply and spread to other areas, eventually forming a microbial film on the gravel surface.

[0057] Simulated wastewater enters the reactor from the top through inlet 1, passes through air cathode 2 and gravel 10, and enters the cathode zone. Microorganisms in the anode zone of the reactor can utilize the organic matter in the wastewater to oxidize and generate electrons, which are transferred to the surface of anode 5 and then through the stainless steel current collector in anode 5. The electrons are then transferred to air cathode 2 through the connecting wires 7 and 8, and the external resistor 3, forming a closed loop (circuit) to generate current. With continuous water intake, direct black BN in the water is removed while achieving high output power density. Continuous water discharge is achieved from outlet 4 through natural overflow.

[0058] It should be noted that the microorganisms that can generate electrons by oxidizing organic matter in wastewater are mainly microorganisms in the anode area, including soil microorganisms, anode microorganisms, and gravel surface microorganisms in the anode area.

[0059] Figure 2 The spectral scans of different concentrations of Direct Black BN standard solutions were obtained using a SHIMADZU UV-2700i instrument. Figure 3 The removal rates of direct black BN in water by Part 2 and Part 3 of the SMFC device using southern red soil as the anode matrix; Figure 4 The power generation voltage of the SMFC unit using southern red soil as the anode substrate under Part 1-3 conditions; Figure 5The power density curves of the SMFC device using southern red soil as the anode matrix are shown in Parts 1-3. It can be seen that the output power density ranges from 0 to 584.8 mW / m³, and the removal efficiency of direct black BN ranges from 0 to 89%. The removal rates of direct black BN in Parts 2 and 3 are both greater than 80%.

[0060] In the anode region of a soil-microbial fuel cell system using an air cathode 2 and Southern Red Soil as the anode substrate, the microorganisms at the anode 5 utilize electrons generated from carbon source oxidation to transfer to the surface of the anode 5, and then via an external circuit to the cathode. This achieves high power output while removing direct black BN from the water. The influent is continuous, and the effluent is naturally overflowing. The reactor is a single, interconnected unit. The gravel support layer helps reduce costs. An plexiglass plate at a specific location in the center of the reactor separates the cathode and anode regions, creating a continuous connection. This interconnected microbial fuel cell system using an air cathode 2 and Southern Red Soil as the anode substrate offers higher power density output while effectively treating direct black BN wastewater. The entire interconnected, naturally overflowing reactor operates continuously using a peristaltic pump. The integrated unit is simple to operate, highly controllable, and ultimately yields higher electrical energy.

[0061] This invention facilitates the generation of electricity while effectively purifying water containing Direct Black (BN) dye, embodying the principles of environmental protection and sustainable development. The air-cathode 2-connected, naturally overflowing microbial fuel cell device using southern red soil as the anode substrate is an integrated design. It boasts advantages such as using southern red soil as the anode substrate, low construction cost, simple and convenient operation, and suitability for practical scenarios, showing broad application prospects in the treatment of dye and other wastewater and the construction of sustainable cities.

[0062] Example 2

[0063] The present invention also provides a method of using the polyazo dye wastewater treatment device described in Example 1, the method comprising:

[0064] Soil 11 is filled into the area above the anode 5 inside the perforated mesh cage 6, which is used to hold soil containing microorganisms. The upper surface of the soil filling the perforated mesh cage is level with the bottom horizontal line of the outlet 4.

[0065] Fill the support layer with filler material.

[0066] A mixed solution of carbon source and polyazo dye wastewater enters the cathode chamber through inlet 1. The carbon source oxidizes to generate electrons, which are then transferred to anode 5 via polyazo dye wastewater solution, soil 11, and microorganisms. The electrons are then transferred to air cathode 2 via wires and external circuits to remove pollutants from the water and generate current. The water after pollutant removal overflows from outlet 4.

[0067] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0068] This document uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. Furthermore, those skilled in the art will recognize that, based on the ideas of the present invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A polyazo dye wastewater treatment apparatus, characterized by comprising: The polyazo dye wastewater treatment device comprises a communicating reactor; The communicating reactor is provided with a support layer for containing the filling material; The communicating reactor is provided with a partition plate in the middle, which is away from the bottom of the communicating reactor by a set distance; the partition plate divides the communicating reactor into an anode chamber and a cathode chamber; The top of the cathode chamber is provided with an air cathode, the anode chamber is provided with a perforated mesh cage, the perforated mesh cage is provided with an anode, and an area for containing soil containing microorganisms is arranged above the anode; the air cathode and the anode are connected to an external circuit through wires; The communicating reactor comprises a water inlet and a water outlet; the water inlet is arranged at the top of the cathode chamber, and the water outlet is arranged at the top of the anode chamber; the water inlet is used to introduce a mixed solution of carbon source and polyazo dye wastewater; In the working process, the soil is filled into the area for containing soil containing microorganisms, the filling material is filled into the support layer, the mixed solution of carbon source and polyazo dye wastewater is introduced into the cathode chamber through the water inlet, the carbon source is oxidized to generate electrons, the electrons are transmitted to the anode through the polyazo dye wastewater solution, the soil and the microorganisms, and then transmitted to the air cathode through the wires and the external circuit, so as to remove the pollutants in the water body and generate electric current; the water after removing the pollutants overflows from the water outlet. The soil is red soil; the microorganisms capable of utilizing the organic matter in the wastewater to generate electrons are mainly the microorganisms in the anode area, including soil microorganisms, microorganisms in the anode and microorganisms on the gravel surface in the anode area.

2. The polyazo dye wastewater treatment apparatus according to claim 1, characterized by The polyazo dye wastewater treatment device further comprises a peristaltic pump connected to the water inlet through a water pipe.

3. The polyazo dye wastewater treatment apparatus according to claim 1, characterized by The air cathode and the anode take graphite felt as the substrate and are wrapped with a stainless steel wire mesh.

4. The polyazo dye wastewater treatment apparatus according to claim 1, characterized by The size of the anode ranges from 1-4 cm in length, 1-4 cm in width and 1-4 cm in thickness; the size of the air cathode ranges from 8-12 cm in length, 8-12 cm in width and 1-4 cm in thickness.

5. The polyazo dye wastewater treatment apparatus according to claim 1, characterized by The external circuit comprises an external resistor connected in series with the air cathode and the anode.

6. The polyazo dye wastewater treatment apparatus according to claim 1, wherein The partition plate is an organic glass partition plate.

7. The polyazo dye wastewater treatment apparatus according to claim 1, characterized by The set distance ranges from 1-4 cm.

8. The polyazo dye wastewater treatment apparatus according to claim 1, characterized by The carbon source is sodium acetate.

9. A method of using a polyazo dye wastewater treatment device according to any one of claims 1-8, characterized in that, The use method comprises: filling the soil into the area for containing soil containing microorganisms above the anode in the perforated mesh cage; filling the filling material into the support layer; introducing the mixed solution of carbon source and polyazo dye wastewater into the cathode chamber through the water inlet, oxidizing the carbon source to generate electrons, transmitting the electrons to the anode through the polyazo dye wastewater solution, the soil and the microorganisms, transmitting the electrons to the air cathode through the wires and the external circuit, removing the pollutants in the water body and generating electric current, and overflowing the water after removing the pollutants from the water outlet.

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