Device for treating phosphorus-containing wastewater by microbial battery coupling electroflocculation structure

Abstract

The application provides a device for treating phosphorus-containing wastewater by a microbial battery coupled electroflocculation structure, which comprises an anode chamber, a wastewater bin and a cathode chamber which are connected in sequence and side by side, the anode chamber is not communicated with the wastewater bin but is provided with an anode film, the wastewater bin is not communicated with the cathode chamber but is provided with a cathode film, an anode device is arranged in the anode chamber, a cathode device is arranged in the cathode chamber, and a stirring device is arranged in the wastewater bin; the device of the application seals the anode chamber, and no raw water enters the anode chamber. In wastewater treatment, raw water can be partially introduced into the anode chamber or be returned to the anode chamber, and organic matters are degraded by microbial adsorption. In short, the device can be expanded to a biological membrane method coupled electroflocculation.

Description

Technical Field

[0001] This application relates to the field of wastewater treatment technology, and in particular to an apparatus for treating phosphorus-containing wastewater using a microbial battery coupled with an electrocoagulation structure. Background Technology

[0002] With rapid industrialization and urbanization, wastewater discharge is increasing daily, among which phosphorus-containing wastewater has attracted much attention due to its significant threat to eutrophication. Phosphorus is one of the main nutrients for eutrophication; excessive phosphorus discharge leads to the proliferation of algae, resulting in algal blooms, anoxic conditions, and a series of other aquatic environmental problems. Therefore, developing efficient and economical phosphorus-containing wastewater treatment technologies is of significant environmental and economic importance.

[0003] Microbial electrochemistry (MET) is a novel wastewater treatment technology that uses electrochemically active microorganisms as catalysts to catalyze the oxidation of organic matter in a system, thereby obtaining electrical signals and recovering resources. In MET, naturally occurring electroactive microorganisms replace expensive precious metal catalysts, reducing capital investment in wastewater treatment. The electrochemical reactions generated by the interaction between electroactive microorganisms and electrodes give MET enormous practical application potential in bioenergy and the conversion of biochemical substances on Earth. The low energy consumption and high-value-added product recovery in wastewater / material treatment processes greatly satisfy the resource recovery and energy output requirements of wastewater treatment. Electroactive microorganisms convert biodegradable organic compounds into carbon dioxide, water, and energy, while the corresponding technology platform collects the energy produced by the microorganisms and provides habitats (electrodes) to maintain their growth and metabolic activities. Therefore, in recent years, researchers have increasingly applied MET to wastewater treatment and management processes, including the treatment of organic wastewater, the recovery of nitrogen and phosphorus nutrients, the reduction and recovery of heavy metals, and the development of online water quality monitoring systems.

[0004] Electrocoagulation is an electrochemical method that uses an aluminum or iron anode to electrolyze and generate aluminum or iron hydroxide colloids under the action of an electric current. Through the adsorption, trapping, and sweeping effects of these colloids, suspended solids and phosphate ions in the water are coagulated, and then the colloids are separated and removed from the water, thus purifying the water. Electrocoagulation technology is characterized by simple equipment, short operating time, easy management, and easy automation. It does not increase secondary pollution and produces little sludge. Simultaneously, it can remove organic matter, bacteria, turbidity, toxic heavy metals, and other pollutants from water, offering many advantages not found in traditional water treatment processes. Compared to chemical flocculation, because the cathode chamber has an aeration device, introducing O2 into the cathode chamber allows O2 to act as an electron acceptor, generating OH-. - It passes through the cathode membrane into the intermediate chamber and reacts with Fe. 3+ Fe(OH)3 colloid is formed. No chemical reagents are needed, therefore SO2 is not produced. -4Cl - Large-scale aggregation of pollutants. Compared to biological treatment, electrocoagulation has a shorter operating time, does not require the cultivation of microorganisms, and only requires electron transfer to achieve water treatment. Therefore, electrocoagulation technology has developed rapidly in recent years and has been widely used. However, using a single technology cannot comprehensively treat wastewater, nor may it necessarily achieve energy-saving goals.

[0005] Microbial battery coupled electrocoagulation technology is an emerging wastewater treatment method. By combining microorganisms attached to the iron electrode in the anode chamber, the microorganisms oxidize iron into iron ions, Fe... 3+ OH- enters the intermediate chamber through the anode membrane and interacts with OH- that enters the intermediate chamber through the cathode membrane from the cathode chamber. - The reaction generates Fe(OH)3 colloids, which are then used for adsorption to effectively treat phosphorus-containing wastewater. This study aims to explore the feasibility of using microbial batteries coupled with electrocoagulation to treat phosphorus-containing wastewater, providing theoretical basis and technical guidance for practical engineering applications. Summary of the Invention

[0006] This application provides an apparatus for treating phosphorus-containing wastewater using a microbial battery coupled with an electrocoagulation structure. In this experimental apparatus, the anode chamber is sealed, preventing any raw water from entering. During wastewater treatment, a portion of the raw water can be introduced into the anode chamber or returned to it, utilizing microorganisms to adsorb and degrade organic matter. In simpler terms, this can be extended to a biofilm method coupled with electrocoagulation.

[0007] In a first aspect, this application provides an apparatus for treating phosphorus-containing wastewater using a microbial battery coupled electrocoagulation structure, comprising an anode chamber, a wastewater tank, and a cathode chamber connected in parallel in sequence. The anode chamber and the wastewater tank are not connected but are provided with an anode membrane. The wastewater tank and the cathode chamber are not connected but are provided with a cathode membrane. An anode device is provided in the anode chamber, a cathode device is provided in the cathode chamber, and a stirring device is provided in the wastewater tank.

[0008] Preferably, the anode chamber, wastewater tank, and cathode chamber are all made of acrylic sheet. A connecting plate is provided on one side of the anode chamber and cathode chamber, and a connecting plate is provided on both sides of the wastewater tank. The connecting plates on both sides of the wastewater tank are fixedly connected to the connecting plates of the anode chamber and cathode chamber by fixing bolts. The anode membrane is sandwiched between the connecting plates of the wastewater tank and the anode chamber; the cathode membrane is sandwiched between the connecting plates of the wastewater tank and the cathode chamber.

[0009] Preferably, the anode device in the anode chamber includes an anode rod and an anode electrode plate connected to the anode rod, the anode rod being fixed in a rubber plug, the rubber plug being installed on the top of the anode chamber (8).

[0010] Preferably, the anode electrode sheet is made of aluminum or iron.

[0011] Preferably, the cathode device in the cathode chamber includes a cathode rod and a carbon rod connected to the cathode rod.

[0012] Preferably, an aeration device is also placed at the bottom of the cathode chamber. Compared with chemical flocculation, because the cathode chamber has an aeration device, when O2 is introduced into the cathode chamber, O2 acts as an electron acceptor, generating OH-. - It passes through the cathode membrane into the intermediate chamber and reacts with Fe. 3+ Fe(OH)3 colloid is formed. No chemical reagents are needed, therefore SO2 is not produced. -4 Cl - A large number of gatherings.

[0013] Preferably, at least one sampler is installed below the anode chamber, wastewater tank, and cathode chamber.

[0014] Preferably, the stirring device installed in the wastewater tank is a stirrer.

[0015] This experimental setup seals the anode chamber, preventing any raw water from entering. In wastewater treatment, a portion of the raw water can be introduced into the anode chamber or returned to it, utilizing microorganisms to adsorb and degrade organic matter. In simpler terms, this can be expanded into a biofilm method coupled with electrocoagulation.

[0016] Microorganisms can provide electrical energy while carrying out redox reactions, causing iron ions to be generated on the iron plate and better combine with hydroxide ions generated in the cathode chamber through the cathode membrane. This device is also an electrocoagulation structure, which removes phosphorus from wastewater by forming metal hydroxide flocculants with iron ions and hydroxide ions under the action of microbial voltage. The main processes are flocculation, sedimentation and adsorption.

[0017] Microbial culture medium is placed in the anode chamber, phosphorus-containing wastewater is placed in the wastewater tank, and electrolyte solution is placed in the cathode chamber. The working process involves first cultivating microorganisms in the anode chamber. Once the microorganisms meet a certain voltage requirement (measured with a DC voltmeter), wastewater is added to the wastewater tank, and the catholyte (electrolyte solution) is placed in the cathode chamber, forming a circuit (connected by wires) to begin treatment. The hydraulic condition is achieved by a stirrer installed on an electric motor, which accelerates the reaction and acts as a catalyst, as a power supply is required. After a certain treatment time, the concentration of the wastewater can be measured.

[0018] The aeration device is placed directly in the catholyte, which helps the catholyte to better obtain dissolved oxygen in the ionized state, and can serve as a catalyst for the reaction in this device.

[0019] As can be seen from the above, the device provided in this application utilizes a combination of microbial batteries and electrocoagulation technology to effectively remove phosphorus from wastewater, thereby purifying the water. Coupled with these two technologies, it not only improves treatment efficiency but also reduces operating costs, energy consumption, and the amount of chemical reagents used, resulting in significant environmental benefits. The device for treating phosphorus-containing wastewater using microbial batteries coupled with electrocoagulation technology has broad application prospects in the environmental protection field and can bring innovation and development to the wastewater treatment industry.

[0020] The beneficial effects of this invention are:

[0021] 1. Integration of environmental protection, energy conservation, and wastewater treatment: Microbial batteries can generate electricity through the oxidation of organic matter, while electrocoagulation technology can efficiently remove particulate matter and phosphate from wastewater. Coupled, these two technologies can achieve both wastewater treatment and environmental protection and energy conservation.

[0022] 2. Enhanced wastewater treatment efficiency: The operation of microbial batteries requires organic matter as a substrate to supply microorganisms. This technology can introduce a portion of the raw water into the anode chamber as a substrate, similar to the biofilm method for treating wastewater, promoting the degradation of organic matter in the wastewater. Meanwhile, the Fe(OH)3 colloid in the intermediate chamber can effectively remove suspended solids and phosphate, resulting in higher wastewater treatment efficiency.

[0023] 3. Reduced use of chemical agents: This coupling technology can remove particulate matter and organic matter from wastewater without the need for additional chemical coagulants, thereby reducing the demand for chemical agents and reducing the impact on the environment.

[0024] 4. Avoid cathode passivation: Due to cathode aeration and the single composition of the catholyte, there is no Ca. 2+ Mg 2+ Plasma avoids cathode passivation. Attached Figure Description

[0025] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 A schematic diagram of the apparatus in Embodiment 1 provided in this application.

[0027] Figure 2 A process diagram of Embodiment 1 provided in this application.

[0028] Figure 3 The catholyte concentration (mol / L) and TP removal rate (%) in Example 2 provided in this application.

[0029] Figure 4 The TP (mg / L) - TP removal rate (%) in wastewater in Example 2 provided in this application.

[0030] Figure 5 The pH-TP removal rate (%) in Example 2 provided in this application.

[0031] Figure 6 Rotation speed (r / min) - TP removal rate (%) in Example 2 provided in this application.

[0032] In the diagram: 1-Agitator; 2-Cathode rod; 3-Carbon rod; 4-Sampler; 5-Aeration device; 6-Fixing bolt; 7-Anode membrane; 8-Anode chamber; 9-Anode rod; 10-Rubber stopper; 11-Anode electrode plate; 12-Cathode membrane; 13-Wastewater tank; 14-Cathode chamber. Detailed Implementation

[0033] The embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements. The embodiments described below do not represent all embodiments consistent with this application. They are merely examples of systems and methods consistent with some aspects of this application as detailed in the claims.

[0034] The present invention will be further described below with reference to specific embodiments.

[0035] Example 1

[0036] like Figure 1 As shown, this embodiment provides an apparatus for treating phosphorus-containing wastewater using a microbial battery coupled with an electrocoagulation structure. The apparatus includes an anode chamber 8, a wastewater tank 13, and a cathode chamber 14 connected in parallel. The anode chamber 8 and the wastewater tank 13 are not connected but are provided with an anode membrane 7. The wastewater tank 13 and the cathode chamber 14 are not connected but are provided with a cathode membrane 12. An anode device is provided in the anode chamber 8, a cathode device is provided in the cathode chamber 14, and a stirring device is provided in the wastewater tank 13.

[0037] In this embodiment, the anode chamber 8, wastewater tank 13, and cathode chamber 14 are all made of acrylic sheets. A connecting plate is provided on one side of the anode chamber 8 and cathode chamber 14, and a connecting plate is provided on both sides of the wastewater tank 13. The connecting plates on both sides of the wastewater tank 13 are fixedly connected to the connecting plates of the anode chamber 8 and cathode chamber 14 by fixing bolts 6. The anode membrane 7 is sandwiched between the connecting plates of the wastewater tank 13 and the anode chamber 8; the cathode membrane 12 is sandwiched between the connecting plates of the wastewater tank 13 and the cathode chamber 14.

[0038] In this embodiment, the anode device in the anode chamber 8 includes an anode rod 9 and an anode electrode plate 11 connected to the anode rod 9. The anode rod 9 is fixed in a rubber plug 10, and the rubber plug 10 is installed on the top of the anode chamber 8.

[0039] In this embodiment, the anode electrode 11 is an aluminum or iron sheet.

[0040] In this embodiment, the cathode device in the cathode chamber 14 includes a cathode rod 2 and a carbon rod 3 connected to the cathode rod 2.

[0041] In this embodiment, an aeration device 5 is also placed at the bottom of the cathode chamber 14. Compared with chemical flocculation, because the cathode chamber has an aeration device, O2 is introduced into the cathode chamber, and O2 acts as an electron acceptor to generate OH-. - It passes through the cathode membrane into the intermediate chamber and reacts with Fe. 3+ Fe(OH)3 colloid is formed. No chemical reagents are needed, therefore SO2 is not produced. -4 Cl - A large number of gatherings.

[0042] In this embodiment, at least one sampler 4 is respectively installed below the anode chamber 8, the wastewater tank 13, and the cathode chamber 14.

[0043] In this embodiment, the stirring device installed in the wastewater tank 13 is a stirrer 1.

[0044] like Figure 2 As shown, this experimental setup seals the anode chamber, preventing raw water from entering. In wastewater treatment, a portion of the raw water can be introduced into the anode chamber or returned to it, utilizing microorganisms to adsorb and degrade organic matter. In simpler terms, this can be extended to a biofilm method coupled with electrocoagulation.

[0045] Microorganisms can provide electrical energy while carrying out redox reactions, causing iron ions to be generated on the iron plate and better combine with hydroxide ions generated in the cathode chamber through the cathode membrane. This device is also an electrocoagulation structure, which removes phosphorus from wastewater by forming metal hydroxide flocculants with iron ions and hydroxide ions under the action of microbial voltage. The main processes are flocculation, sedimentation and adsorption.

[0046] The device for treating phosphorus-containing wastewater using a microbial battery coupled with an electrocoagulation structure involves first cultivating microorganisms in the anode chamber, then adding wastewater (measuring with a DC voltmeter) to the wastewater tank and the cathode solution (electrolyte solution) to the cathode chamber, thus forming a circuit (connected by wires). The hydraulic condition is achieved by an agitator set by an electric motor to accelerate the reaction; this also acts as a catalyst, as a power supply is required. After a certain treatment time, the concentration of the wastewater can be measured.

[0047] The aeration device is placed directly in the catholyte, which helps the catholyte to better obtain dissolved oxygen in the ionized state, and can serve as a catalyst for the reaction in this device.

[0048] Example 2

[0049] This embodiment provides experimental and result analysis.

[0050] 1. Experimental Reagents

[0051] 1.1 Microbial culture medium

[0052] Microbial culture mainly requires microbial phosphate buffer, trace elements, and microbial solution, the specific contents of which are shown in the table below:

[0053] Table 1-1 Phosphate Buffer Table

[0054]

[0055] Table 1-2 Trace Elements Table

[0056]

[0057] Table 1-3 Vitamin Solution Table

[0058]

[0059]

[0060] 1.2 Phosphorus-containing wastewater

[0061] The experimental water sample was prepared using potassium dihydrogen phosphate and dipotassium hydrogen phosphate to simulate phosphorus-containing wastewater, with a TP concentration of 40.0 (±0.5) mg / L and a pH of 7.04 (±0.02).

[0062] 1.3 Reagents for determining phosphorus-containing wastewater

[0063] 1. (1+1) sulfuric acid

[0064] 2. 10% Ascorbic Acid: Dissolve 10g of ascorbic acid in water and dilute to 100ml.

[0065] 3. Molybdate solution: Add 8g of ammonium molybdate (NH4)6Mo7O 24 Dissolve 0.35 g of potassium antimony tartrate K(SbO)C4H4O6·1 / 2H2O in 100 mL of water. While stirring continuously, slowly add the ammonium molybdate solution to 300 mL of sulfuric acid, then add the potassium antimony tartrate solution and mix thoroughly.

[0066] 4. Turbidity-color compensation solution: Mix two volumes of sulfuric acid and one volume of 10% ascorbic acid solution.

[0067] 5. Phosphate stock solution: Dry the superior grade potassium dihydrogen phosphate (KH₂PO₄) at 110°C for 2 hours, and cool it in a desiccator. Weigh 0.2179 g, dissolve it in water, transfer it to a 1000 mL volumetric flask, add 5 mL of sulfuric acid, and dilute with water to the mark.

[0068] 6. Phosphate standard solution: Pipette 10 mL of phosphate stock solution into a 250 mL volumetric flask and dilute with water to the mark.

[0069] 2 Experimental Results

[0070] 2.1 Effect of cathodic liquid concentration on the experiment

[0071] An electrocoagulation experiment was conducted using raw water with a concentration of 100 mg / L and pH = 7.00, and a motor speed of 500 r / min. Samples were taken every 1 hour, filtered, digested, and the phosphorus concentration in the electrolyte was measured to calculate the removal rate, exploring the effect of the catholyte on TP removal. NaCl solution was used as the catholyte. Due to temperature limitations, the solubility of NaCl is affected by temperature; concentrations exceeding 2 mol / L will cause precipitation. Therefore, NaCl solutions with concentrations of 0, 0.5, 1, 1.5, and 2 mol / L were prepared. The experimental results are as follows: Figure 3 As shown in Figure 3, the results indicate that a higher catholyte concentration can improve the removal efficiency of TP.

[0072] 2.2 Effect of total phosphorus content in wastewater on the experiment

[0073] Electrocoagulation experiments were conducted using raw water concentrations of 0, 50, 100, 140, and 200 mg / L, pH = 7.00, and catholyte concentration of 1 mol / L, with a motor speed of 500 r / min. Samples were taken every 1 hour, filtered, digested, and the phosphorus concentration in the electrolyte was measured. The removal rate was calculated to investigate the effect of the catholyte on TP removal. The results are as follows: Figure 4 As shown in Figure 4, the removal rate is optimal when the phosphorus concentration in the wastewater is 100 mg / L.

[0074] 2.3 Effect of pH value on the experiment

[0075] Raw water samples with pH values ​​of 10.65, 8.8, 7.00, 5.70, and 4.45 were used. All raw water samples contained a phosphorus concentration of 100 mg / L, and the catholyte concentration was 1 mol / L. Electrocoagulation experiments were conducted at a rotation speed of 500 r / min. Samples were taken every 1 hour, filtered, digested, and the phosphorus concentration in the electrolyte was measured. The removal rate was calculated, and the effect of raw water pH on TP removal efficiency was analyzed. Results are as follows: Figure 5 As shown in Figure 5, a slightly alkaline pH level is beneficial for the removal of phosphorus-containing wastewater. The higher the hydroxide content in the wastewater, the easier it is for it to react with the ferric ions generated at the anode to form ferric hydroxide colloid.

[0076] 2.4 Hydraulic conditions

[0077] The raw water concentration was 100 mg / L, the catholyte concentration was 1 mol / L, and the pH was 7.00. Electrocoagulation experiments were conducted using an electric motor at speeds of 0 r / min, 250 r / min, 500 r / min, 750 r / min, and 1000 r / min. Samples were taken every hour, filtered, digested, and the phosphorus concentration in the electrolyte was measured. The removal rate was calculated, and the influence of hydraulic conditions on the TP removal effect was analyzed. The results are as follows: Figure 6 As shown, according to Figure 6 The results show that the higher the rotation speed, the better the removal effect of phosphorus-containing wastewater. Increasing the rotation speed increases the amount of Fe in the intermediate chamber. 3+ With OH - The effective number of collisions promotes the formation of Fe(OH)3 colloids.

[0078] Similar parts between the embodiments provided in this application can be referred to mutually. The specific implementation methods provided above are only a few examples under the overall concept of this application and do not constitute a limitation on the scope of protection of this application. For those skilled in the art, any other implementation methods extended from the solution of this application without creative effort shall fall within the scope of protection of this application.

Claims

1. A device for treating phosphorus-containing wastewater using a microbial battery coupled with an electrocoagulation structure, characterized in that, The device includes an anode chamber (8), a wastewater tank (13), and a cathode chamber (14) connected in parallel. The anode chamber (8) and the wastewater tank (13) are not connected but are provided with an anode membrane (7). The wastewater tank (13) and the cathode chamber (14) are not connected but are provided with a cathode membrane (12). An anode device is provided in the anode chamber (8), a cathode device is provided in the cathode chamber (14), and a stirring device is provided in the wastewater tank (13). The anode chamber is used to hold microbial culture medium, the wastewater tank is used to hold phosphorus-containing wastewater, and the cathode chamber is used to hold an electrolyte solution, which is a NaCl solution. The anode device in the anode chamber (8) includes an anode rod (9) and an anode electrode plate (11) connected to the anode rod (9). The anode rod (9) is fixed in a rubber plug (10), which is installed on the top of the anode chamber (8). The anode electrode sheet (11) is made of aluminum or iron; the cathode device in the cathode chamber (14) includes a cathode rod (2) and a carbon rod (3) connected to the cathode rod (2); an aeration device (5) is also placed at the bottom of the cathode chamber (14).

2. The apparatus according to claim 1, characterized in that, The anode chamber (8), wastewater tank (13), and cathode chamber (14) are all made of acrylic sheet. A connecting plate is provided on one side of the anode chamber (8) and cathode chamber (14), and a connecting plate is provided on both sides of the wastewater tank (13). The connecting plates on both sides of the wastewater tank (13) are fixedly connected to the connecting plates of the anode chamber (8) and cathode chamber (14) by fixing bolts (6). The anode membrane (7) is sandwiched between the connecting plates of the wastewater tank (13) and the anode chamber (8); the cathode membrane (12) is sandwiched between the connecting plates of the wastewater tank (13) and the cathode chamber (14).

3. The apparatus according to claim 1, characterized in that, At least one sampler (4) is installed below the anode chamber (8), the wastewater tank (13), and the cathode chamber (14).

4. The apparatus according to claim 1, characterized in that, The stirring device installed in the wastewater tank (13) is a stirrer (1).

Images