Method and device for enhancing production of methane from sulfur-containing organic wastewater by intermittently electrically stimulating microorganisms

Abstract

The invention discloses an intermittent electrical stimulation microorganism enhanced methane production method and a device thereof, which are used for treating sulfur-containing organic wastewater. The intermittent electric field acts on the electrodes in the reaction tank, H < + > generated by the anaerobic sludge blanket at the bottom is combined with the cathode to generate H2, the concentration of H < + > is effectively reduced, and the pH value is increased. According to the technology, the pH is automatically adjusted by controlling the electrifying time, the inhibition effect of H2S on methane-producing bacteria is relieved, the yield and purity of methane are improved, and the problems that the pH adjustment cost of a traditional chemical method is high and the efficiency of a bioelectrochemical process is low are solved. The device adopts an up-flow biological anaerobic reaction tank, is equipped with a direct-current power supply controller and a self-adjusting pH controller, and is internally provided with a pH probe and a dual-electrode system, so that the whole reaction is carried out in an anaerobic environment. And the generated gas is conveyed to a gas collecting tank through a pipeline to be purified and stored. The system optimizes the operation through the real-time monitoring and data analysis module, reduces the processing cost, and increases the economic benefits at the same time.

Description

Technical Field

[0001] The invention relates to the technical field of waste liquid treatment, and in particular to a treatment method and device for intermittently electrically stimulating microorganisms to enhance methane production in sulfur-containing organic wastewater. Background Art

[0002] With the rapid development of the national economy and society, the process of industrialization has not only brought economic growth, but also aggravated environmental problems, especially the pollution of industrial wastewater. Wastewater generated by industries such as pharmaceuticals, chemicals, papermaking and mineral processing contains high concentrations of organic matter and sulfate. If these wastewaters are discharged directly without treatment, they will seriously affect the water quality, reduce the pH value, and endanger the survival of aquatic organisms; at the same time, wastewater with high sulfate content discharged into farmland may also destroy the soil structure, reduce the permeability and water retention of the soil, and lead to reduced crop yields and reduced quality of agricultural products. In addition, hydrogen sulfide (H2S) generated by sulfate-reducing bacteria under anaerobic conditions is not only highly corrosive to metal structures and pipelines, but its high concentration may also pose a major threat to human health and cause poisoning of the respiratory and nervous systems.

[0003] In the treatment of sulfate-containing organic wastewater, although traditional anaerobic treatment technologies can degrade organic matter to a certain extent, these methods have limited effect in treating high-concentration sulfate wastewater. The production of hydrogen sulfide not only inhibits the activity of methanogens and reduces the yield of biogas, but also often leads to inefficient treatment systems, easy rancidity and stagnation. In addition, these methods usually require large reaction volumes and long cycles, increasing treatment costs. Although there are chemical methods on the market, such as adding alkaline chemicals to adjust the pH value to inhibit the generation of hydrogen sulfide, such methods are often costly and may introduce new environmental problems, such as the emission of chemical pollutants. Therefore, these methods face challenges in terms of economic benefits and environmental sustainability.

[0004] In addition, although researchers have tried to enhance microbial activity and improve the degradation rate of organic matter through bioelectrochemical systems, these systems are usually complex and energy-intensive, making them difficult to be widely used on an industrial scale. Therefore, the development of a new technology that can effectively treat sulfur-containing organic wastewater, optimize energy recovery, and be economically feasible has become an urgent need in this field. Summary of the invention

[0005] In view of the deficiencies in the prior art, the present invention provides a method and device for treating sulfur-containing organic wastewater by intermittent electrical stimulation of microorganisms to enhance methane production with high efficiency and low energy consumption.

[0006] To solve the above problems, the technical solution adopted by the present invention is:

[0007] A method and device for intermittent electrical stimulation of microorganisms to enhance the production of methane from sulfur-containing organic wastewater, characterized in that the device includes an upflow biological anaerobic reactor, a self-adjusting pH controller, a DC power supply controller and a gas collecting tank. The upflow biological anaerobic reactor is equipped with a bottom sludge bed, a cathode, an anode and a self-adjusting pH controller, and the anode and cathode are respectively connected to the positive and negative electrodes of an external DC power supply controller; the self-adjusting pH controller is connected in series with the DC power supply controller; the exhaust port at the top of the reactor is connected to the air inlet of the gas collecting tank, and the gas collecting tank is a methane purification gas collecting tank. The upflow biological anaerobic reactor is equipped with a bottom sludge bed, as well as cathodes and anodes with optimized layouts, and both cathodes and anodes are connected to an external DC power supply controller; the self-adjusting pH controller is connected in series with the DC power supply controller to control the power switch according to the pH value in the water; the exhaust port at the top of the reactor is connected to the air inlet of the gas collecting tank, and the gas collecting tank is dedicated to the purification and storage of methane.

[0008] The cathode is an immobilized combined biological filler electrode, which is provided with a supporting and fixed structure, and the immobilized biological filler is suspended on the structure, and multiple layers of the cathode are connected in series; the immobilized combined biological filler electrode includes multiple filler modules, and the filler modules are evenly distributed on the cathode; a domesticated biocompatible conductor electrode is placed on the cathode fixing bracket; the cathode is located above the sludge bed layer; the biocompatible conductor electrode is carbon cloth, carbon fiber cloth, carbon felt, granular activated carbon or biochar.

[0009] The anode is an immobilized conductor electrode, provided with a supporting and fixed structure, and the immobilized biological filler is suspended on the structure, and multiple layers of the anode are connected in series; the anode is located above the pH identification probe; the anode material is a stainless steel mesh, a nickel mesh or a titanium mesh.

[0010] The self-adjusting pH controller includes a pH identification probe, a data acquisition module, a data analysis module and a pH control module; the pH identification probe monitors the pH in water in real time and transmits the data to the data acquisition module, which then evaluates whether it exceeds the optimal growth pH environment of methanogens (7.5 to 8.5). If it exceeds, the control module instructs the DC power supply controller to cut off the power supply to adjust the reaction conditions, otherwise it continues to supply power.

[0011] The DC power supply controller includes a control module, a power switch, and a power input and output interface connected to the control module and the power switch. The control module is used to receive a signal from the data analysis module and control the state of the power switch according to the signal. When the data analysis module determines that the pH of the water exceeds the suitable environment of the methanogens, the control module automatically cuts off the power switch to implement a power-off operation to protect the water quality environment. On the contrary, when the pH of the water is within the appropriate range, the control module turns on the power switch to ensure normal power supply. The power switch is used to control the on and off of the power supply to ensure that the water treatment is timely and effective.

[0012] The pH identification probe is located between the cathode and the anode, is provided with a retractable frame and a hinge, and is fixed on a pipe made of carbon steel Q235 or stainless steel 304, allowing the pH probe to be quickly replaced through simple operation when damaged, thereby improving maintenance efficiency.

[0013] The present invention also provides a method for treating sulfur-containing organic wastewater by intermittent electrical stimulation of microorganisms to enhance methane production, which comprises the following steps:

[0014] The sulfur-containing organic wastewater is sent into the upflow biological anaerobic reactor in a continuous flow through the water inlet pump and evenly distributed through the bottom water outlet; the cathode is located above the sludge bed, and the anode is used as an electron donor to promote the electrolysis reaction under the power-on state; the cathode and the anode are connected to lead out of the reactor, and are connected in series with the self-adjusting pH controller and the DC power supply controller to form a closed loop; the acquisition module of the pH identification probe collects the pH data in the reactor in real time and transmits it to the data analysis module. When the pH value range exceeds the good growth environment of methanogens (7.5-8.5), the data analysis module will issue an instruction to the control module to cut off the power supply, otherwise it will connect the power supply. The generated methane gas is mixed with H2S gas, which enters the methane purification gas collection tank from the top exhaust port, and the H2S is removed in the gas collection tank by the NaOH eluent, thereby obtaining pure methane, and the NaOH eluent can be circulated and eluted by the water pump.

[0015] The cathode is inoculated with sludge, and anaerobic granular activated sludge used to treat sulfate-containing organic wastewater is inoculated at the bottom of the reaction tank. During the acclimation period, sulfur-containing organic wastewater is used as influent until a high-concentration, high-activity sludge layer is formed at the bottom of the reaction tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 Schematic diagram of the overall structure of the device of the present invention

[0017] Figure 2 The framework diagram of the self-regulating pH controller of the present invention is

[0018] Figure 3 This is the operation flow chart of the self-regulating pH controller of the present invention. DETAILED DESCRIPTION

[0019] The preferred technical solutions of the present invention are described in detail below with reference to the accompanying drawings.

[0020] The present invention discloses a method and device for intermittent electrical stimulation of microorganisms to enhance the production of methane from sulfur-containing organic wastewater, characterized in that the device includes an upflow biological anaerobic reaction tank, a self-adjusting pH controller, a direct current power supply controller and a gas collecting tank. The upflow biological anaerobic reaction tank is equipped with a bottom sludge bed, a cathode, an anode and a self-adjusting pH controller, and the anode and the cathode are respectively connected to the positive and negative electrodes of an external direct current power supply controller; the self-adjusting pH controller is connected in series with the direct current power supply controller; the exhaust port at the top of the reaction tank is connected to the air inlet of the gas collecting tank, and the gas collecting tank is a methane purification gas collecting tank. The upflow biological anaerobic reaction tank is equipped with a bottom sludge bed, as well as cathodes and anodes with optimized layouts, and both cathodes and anodes are connected to an external direct current power supply controller; the self-adjusting pH controller is connected in series with the direct current power supply controller to control the power switch according to the pH value in the water; the exhaust port at the top of the reaction tank is connected to the air inlet of the gas collecting tank, and the gas collecting tank is dedicated to the purification and storage of methane.

[0021] The cathode is an immobilized combined biological filler electrode, which is provided with a supporting and fixed structure, and the immobilized biological filler is suspended on the structure, and multiple layers of the cathode are connected in series; the immobilized combined biological filler electrode includes multiple filler modules, and the filler modules are evenly distributed on the cathode; a domesticated biocompatible conductor electrode is placed on the cathode fixing bracket; the cathode is located above the sludge bed layer; the biocompatible conductor electrode is carbon cloth, carbon fiber cloth, carbon felt, granular activated carbon or biochar.

[0022] The anode is an immobilized conductor electrode, provided with a supporting and fixed structure, and the immobilized biological filler is suspended on the structure, and multiple layers of the anode are connected in series; the anode is located above the pH identification probe; the anode material is a stainless steel mesh, a nickel mesh or a titanium mesh.

[0023] The self-adjusting pH controller includes a pH identification probe, a data acquisition module, a data analysis module and a pH control module; the pH identification probe monitors the pH in water in real time and transmits the data to the data acquisition module, which then evaluates whether it exceeds the optimal growth pH environment of methanogens (7.5 to 8.5). If it exceeds, the control module instructs the DC power supply controller to cut off the power supply to adjust the reaction conditions, otherwise it continues to supply power.

[0024] The DC power supply controller includes a control module, a power switch, and a power input and output interface connected to the control module and the power switch. The control module is used to receive a signal from the data analysis module and control the state of the power switch according to the signal. When the data analysis module determines that the pH of the water exceeds the suitable environment of the methanogens, the control module automatically cuts off the power switch to implement a power-off operation to protect the water quality environment. On the contrary, when the pH of the water is within the appropriate range, the control module turns on the power switch to ensure normal power supply. The power switch is used to control the on and off of the power supply to ensure that the water treatment is timely and effective.

[0025] The pH identification probe is located between the cathode and the anode, is provided with a retractable frame and a hinge, and is fixed on a pipe made of carbon steel Q235 or stainless steel 304, allowing the pH probe to be quickly replaced through simple operation when damaged, thereby improving maintenance efficiency.

[0026] The present invention also provides a method for treating sulfur-containing organic wastewater by intermittent electrical stimulation of microorganisms to enhance methane production, which comprises the following steps:

[0027] The sulfur-containing organic wastewater is sent into the upflow biological anaerobic reactor in a continuous flow through the water inlet pump and evenly distributed through the bottom water outlet; the cathode is located above the sludge bed, and the anode is used as an electron donor to promote the electrolysis reaction under the power-on state; the cathode and the anode are connected to lead out of the reactor, and are connected in series with the self-adjusting pH controller and the DC power supply controller to form a closed loop; the acquisition module of the pH identification probe collects the pH data in the reactor in real time and transmits it to the data analysis module. When the pH value range exceeds the good growth environment of methanogens (7.5-8.5), the data analysis module will issue an instruction to the control module to cut off the power supply, otherwise it will connect the power supply. The generated methane gas is mixed with H2S gas, which enters the methane purification gas collection tank from the top exhaust port, and the H2S is removed in the gas collection tank by the NaOH eluent, thereby obtaining pure methane, and the NaOH eluent can be circulated and eluted by the water pump.

[0028] The cathode is inoculated with sludge, and anaerobic granular activated sludge used to treat sulfate-containing organic wastewater is inoculated at the bottom of the reaction tank. During the acclimation period, sulfur-containing organic wastewater is used as influent until a high-concentration, high-activity sludge layer is formed at the bottom of the reaction tank.

[0029] The above is only a preferred specific implementation manner of the present invention, and the protection scope of the present invention is not limited thereto. Any simple change or equivalent replacement of the technical solution that can be obviously obtained by any technician familiar with the technical field within the technical scope disclosed in the present invention falls within the protection scope of the present invention.

Claims

1. A method and device for intermittent electrical stimulation of microorganisms to enhance methane production from sulfur-containing organic wastewater, characterized in that: The device includes an upflow biological anaerobic reaction tank, a self-adjusting pH controller, a DC power supply controller and a gas collecting tank. The upflow biological anaerobic reaction tank is equipped with a bottom sludge bed, a cathode, an anode and a self-adjusting pH controller, and the anode and cathode are respectively connected to the positive and negative electrodes of an external DC power supply controller; the self-adjusting pH controller is connected in series with the DC power supply controller; the exhaust port at the top of the reaction tank is connected to the air inlet of the gas collecting tank, and the gas collecting tank is a methane purification gas collecting tank. The upflow biological anaerobic reaction tank is equipped with a bottom sludge bed, as well as cathodes and anodes with optimized layouts, and both cathodes and anodes are connected to an external DC power supply controller; the self-adjusting pH controller is connected in series with the DC power supply controller to control the power switch according to the pH value in the water; the exhaust port at the top of the reaction tank is connected to the air inlet of the gas collecting tank, and the gas collecting tank is dedicated to the purification and storage of methane.

2. The device according to claim 1, characterized in that: The cathode is an immobilized combined biological filler electrode, which is provided with a supporting and fixed structure, and the immobilized biological filler is suspended on the structure, and multiple layers of the cathode are connected in series; the immobilized combined biological filler electrode includes multiple filler modules, and the filler modules are evenly distributed on the cathode; a domesticated biocompatible conductor electrode is placed on the cathode fixing bracket; the cathode is located above the sludge bed layer; the biocompatible conductor electrode is carbon cloth, carbon fiber cloth, carbon felt, granular activated carbon or biochar.

3. The device according to claim 1, characterized in that: The anode is an immobilized conductor electrode, provided with a supporting and fixed structure, and the immobilized biological filler is suspended on the structure, and multiple layers of the anode are connected in series; the anode is located above the pH identification probe; the anode material is a stainless steel mesh, a nickel mesh or a titanium mesh.

4. The device according to claim 1, characterized in that: The self-regulating pH controller includes a pH identification probe, a data acquisition module, a data analysis module and a pH control module; The pH identification probe monitors the pH value in the water in real time and transmits the data to the data acquisition module, which then evaluates whether it exceeds the optimal pH environment for the growth of methanogens (7.5 to 8.5). If so, the control module instructs the DC power controller to cut off the power supply to adjust the reaction conditions, otherwise it continues to supply power.

5. The device according to claim 1, characterized in that: The DC power supply controller includes a control module, a power switch, and a power input and output interface connected to the control module and the power switch. The control module is used to receive a signal from the data analysis module and control the state of the power switch according to the signal. When the data analysis module determines that the pH of the water exceeds the suitable environment of the methanogens, the control module automatically cuts off the power switch to implement a power-off operation to protect the water quality environment. On the contrary, when the pH of the water is within the appropriate range, the control module turns on the power switch to ensure normal power supply. The power switch is used to control the on and off of the power supply to ensure that the water treatment is timely and effective.

6. The device according to claim 1, characterized in that: The pH identification probe is located between the cathode and the anode, is provided with a retractable frame and a hinge, and is fixed on a pipe made of carbon steel Q235 or stainless steel 304, allowing the pH probe to be quickly replaced through simple operation when damaged, thereby improving maintenance efficiency.

7. A method for treating sulfur-containing organic wastewater by intermittent electrical stimulation of microorganisms to enhance methane production, characterized in that: The following steps are involved: The sulfur-containing organic wastewater is sent into the upflow biological anaerobic reaction tank through the water inlet pump in a continuous flow mode and evenly distributed through the bottom water outlet; The cathode is located above the sludge bed, and the anode acts as an electron donor to promote the electrolysis reaction under power-on. The cathode and the anode are connected to lead out of the reaction tank, and are connected in series with the self-adjusting pH controller and the DC power controller to form a closed loop. The acquisition module of the pH identification probe collects the pH data in the reaction tank in real time and transmits it to the data analysis module. When the pH value range exceeds the good growth environment of methanogens (7.5-8.5), the data analysis module will issue an instruction to the control module to cut off the power supply, otherwise it will connect the power supply. The generated methane gas is mixed with H2S gas, which enters the methane purification gas collection tank from the top exhaust port, and the H2S is removed in the gas collection tank by NaOH eluent, thereby obtaining pure methane. The NaOH eluent can be circulated and eluted by a water pump. The cathode is inoculated with sludge for acclimation, and anaerobic granular activated sludge for treating sulfate-containing organic wastewater is inoculated at the bottom of the reaction tank. During the acclimation period, sulfur-containing organic wastewater is used as influent until a high-concentration, high-activity sludge layer is formed at the bottom of the reaction tank.

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