CN117430280A - Novel method for coupling treatment of high-salt organic wastewater by microalgae type microbial fuel cell - Google Patents

Abstract

A novel method for coupling treatment of high-salt organic wastewater by a microalgae type microbial fuel cell belongs to the technical fields of wastewater treatment and wastewater resource utilization. The method specifically comprises the following steps: s1, inputting high-salt organic wastewater into an adjusting tank; s2, the effluent of the regulating tank enters a pre-sedimentation oxidation tank; s3, the effluent of the pre-precipitation oxidation pond enters a microalgae type microbial fuel cell; s4, enabling the effluent of the microalgae type microbial fuel cell to enter a UV photolysis oxidation pond. The double-chamber microalgae type Microbial Fuel Cell (MFC) constructed by the invention takes mixed bacteria inoculated in a primary sedimentation tank of a sewage plant as an anode chamber, microalgae inoculated as a cathode, high-concentration organic wastewater as a substrate, and operates the MFC at room temperature and constant pressure, so that organic pollutants in the mixed wastewater can be removed, and meanwhile, electric energy can be recovered. The method has the advantages of simple equipment, convenient operation, energy conservation and no secondary pollution. After this process, the Chemical Oxygen Demand (COD) was reduced from 5000 to 32 and the Biochemical Oxygen Demand (BOD) was reduced from 1000 to 12.

Description

A new method of coupling microalgae-based microbial fuel cells to treat high-salt organic wastewater

Technical field

The invention relates to a new method for coupling treatment of high-salt organic wastewater with microalgae-type microbial fuel cells, and belongs to the technical field of wastewater resource utilization.

Background technique

Microbial Fuel Cells (MFCs) are a new wastewater energy technology that utilizes the catalytic effect of electricity-producing microorganisms to convert the chemical energy contained in organic matter in wastewater into electrical energy to degrade organic pollutants in wastewater and The dual purpose of electrical energy recovery. Therefore, MFCs technology is the most in line with my country's "green development" concept and ecological civilization construction in the process of realizing wastewater energy. It can effectively alleviate the energy crisis and water crisis and open a new chapter in wastewater treatment.

The present invention uses a double-chamber microalgae microbial fuel cell, adds chlorella to the cathode chamber, and is coupled with other sewage treatment technologies. It uses actual high-salt organic wastewater as the treatment object to achieve high-efficiency power generation while having a removal effect on pollutants. Application prospects.

Contents of the invention

The purpose of the present invention is to provide a low-cost, green and environmentally friendly new method for coupling treatment of high-salt organic wastewater with a microalgae-type microbial fuel cell, so that the wastewater can be effectively degraded and electricity can be produced at the same time.

The technical solutions adopted by the present invention are as follows:

A new method of coupling microalgae-type microbial fuel cells to treat high-salt organic wastewater. The process includes four processes: a conditioning tank, a pre-sedimentation oxidation tank, a microalgae-type microbial fuel cell, and a UV photolysis oxidation tank. Specifically, it includes:

In the first step S1, high-salt organic wastewater is input into the regulating tank to adjust water quality and quantity;

In the second step S2, the pre-sedimentation oxidation tank is composed of a gravel layer and an iron-carbon micro-electrolysis filler layer from bottom to top;

In the third step S3, it includes an anode chamber, a cathode chamber and a proton exchange membrane. The anode chamber and the cathode chamber are connected and the inner chambers are connected. The proton exchange membrane is arranged between the anode chamber and the cathode chamber. The anode chamber is equipped with an anode terminal reaction electrode. The anode wire is connected to the reaction electrode at the anode end. There is an anode cover plate on the top of the anode chamber. The anode cover plate has an anode top cover gas discharge and collection hole, a first outlet hole, a first reference electrode fixing hole and a first top inlet hole. Water inlet; the anode wire passes through the anode chamber from the first outlet hole. The structure of the cathode chamber is the same as that of the anode chamber. Both the anode chamber and the cathode chamber are filled with microbial fuel;

In the fourth step S4, ultraviolet light is used as energy and nano-TiO2 is used as a catalyst to degrade organic matter into other harmless components such as carbon dioxide and water, so that the treated wastewater can be discharged up to standard.

In the method described above, in the second step S2, the height of the gravel layer is 200-400 mm, and the height of the iron-carbon micro-electrolytic filler layer is 300-600 mm, preferably 500 mm.

In the method described, in the third step S3, the effective volumes of the anode chamber and the cathode chamber are both 2000 mL, and are connected through flanges, separated by proton exchange membranes, except for the feeding port and wire hole reserved on the upper cover of the device. Externally, the anode chamber is in a sealed state to ensure that it is in an anaerobic environment, and the cathode chamber is in a semi-sealed state to prevent the catholyte from evaporating too quickly. Carbon cloth is used as the electrode, and the cathode and anode are connected to the external circuit using titanium wire with a diameter of 0.5cm. , the external resistance is 1000Ω, and the MFC voltage data is collected with a parallel data acquisition instrument.

In the described method, in the third step S3, BG11 culture medium is used in the cathode chamber to inoculate chlorella.

In the described method, in the fourth step S4, the hydrogen peroxide in the treated water treated by the ultraviolet oxidation device is increased, and part of the treated water is returned to the cathode of the microalgae-type microbial fuel cell in S3, thereby promoting the microbial fuel cell. ion exchange within.

[The beneficial effects of the above technical solutions of the present invention are as follows]:

First, microalgae MFCs technology can greatly improve the treatment efficiency of nitrogen, phosphorus and heavy metals through this process, reduce the ecological impact of effluent on natural water bodies, and at the same time realize the conversion of chemical energy into electrical energy, turning sewage into clean water and electricity.

Second, apply MFCs to high-salt organic wastewater treatment, explore the factors that affect the power generation performance of microalgae biocathode MFCs, and elaborate on the main concepts and directions of future research on microalgae biocathode MFCs, hoping that they can replace fossil fuels Become a new type of clean energy that can be widely used. Taking the goal of carbon neutrality as an opportunity, we will develop new green, low-carbon and sustainable processes to achieve the synergy of pollution reduction, carbon reduction, and energy conservation.

Description of the drawings

Figure 1 is a schematic diagram of a double-chamber microalgae microbial fuel cell device. In the figure: 1. Regulation tank, 2. Pre-sedimentation oxidation tank, 2-1. Iron-carbon micro-electrolysis filler layer, 2-2. Gravel layer, 3. Micro Algae microbial fuel cell, 3-1. Anode, 3-2. Cathode, 3-3. Microorganisms, 3-4 Chlorella, 3-5. Top exhaust port of the anode, 3-6. Top exhaust port of the cathode , 3-7. Vent at the bottom of the anode, 3-8. Vent at the bottom of the cathode, 3-9. Proton exchange membrane, 3-10. Flange, 3-11. Wire, 3-12. External resistance, 3-13 .Data acquisition system, 4. UV photolysis oxidation tank, 4-1. Ultraviolet radiation light source, 4-2. Return port;

Detailed ways

The above contents of the present invention will be further described in detail below in the form of examples. However, this should not be understood to mean that the scope of the above subject matter of the present invention is limited to the following examples. All technologies implemented based on the above contents of the present invention belong to scope of the invention.

In the description of the present invention, it should also be noted that the orientation or positional relationship is based on the relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, and does not indicate or imply the device or element referred to. Must have a specific orientation, be constructed and operate in a specific orientation and are therefore not to be construed as limitations of the invention. Furthermore, terms such as "first, second or third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance. Unless otherwise expressly stated and limited in the present invention. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

The present invention will be further described below in conjunction with the drawings and examples.

A new method of coupling microalgae-based microbial fuel cells to treat high-salt organic wastewater. As shown in Figure 1, the high-salt organic wastewater passes through the regulating tank, pre-sedimentation oxidation tank, microalgae-based microbial fuel cell, and UV photolysis oxidation tank in sequence. .

In one embodiment, the method includes,

1. High-salt organic wastewater first enters the regulating tank 1 to adjust water quality and quantity;

2. The effluent from the regulating tank enters the pre-sedimentation oxidation tank 2, and passes through the gravel layer 2-2 and the iron-carbon micro-electrolytic filler layer 2-1 in sequence;

3. The effluent from the pre-sedimentation oxidation tank enters the microalgae-type microbial fuel cell 3. According to the properties of the pollutants, the pollutants are effectively degraded by controlling the pH, microbial concentration, and chlorella content;

4. The microalgae microbial fuel cell discharges water and the wastewater enters the UV photolysis oxidation tank 4. The UV photolysis oxidation tank is equipped with an ultraviolet radiation source 4-1 and a return port 4-2. It adopts water-immersed UV disinfection equipment and part of the water passes through the reflux Port 4-2 flows back to the cathode chamber 3 of the microalgae microbial fuel cell, and the effluent reaches the standard for discharge.

Further specifically, in step 2, the height of the gravel layer is 200-400 mm, and the height of the iron-carbon micro-electrolytic filler layer is 300-600 mm, preferably 500 mm. This process can not only remove suspended particles from the water body, but also carry out the collaborative sedimentation and removal of some organic pollutants and inorganic ions through intermolecular forces and electrostatic attraction during the formation of large-volume flocs. At the same time, the dissolved state of the iron-based flocculant will adjust the pH of the water body, neutralize the alkaline water body to achieve acidity, provide hydrolysis and acidification conditions for the subsequent anaerobic process, avoid setting up a hydrolysis acidification tank, and reduce construction costs.

More specifically in step 3, the microalgae microbial fuel cell includes an anode chamber, a cathode chamber, a proton exchange membrane 3-9, and a flange 3-10. The anode chamber includes anode 3-1, anode top exhaust port 3-5, and anode bottom vent 3-7. The cathode chamber includes a cathode 3-2, cathode top exhaust port 3-6, and cathode bottom vent 3-8. The anode and cathode are mainly carbon materials such as activated carbon fiber, carbon cloth, and carbon felt. The effective volumes of the anode chamber and the cathode chamber are both 2000mL, and are connected through flanges 3-10, separated by proton exchange membranes 3-9. The anode chamber is sealed except for the feeding port and wire holes reserved on the upper cover of the device. state to ensure that it is in an anaerobic environment. The cathode chamber is in a semi-sealed state to prevent the catholyte from evaporating too quickly. Carbon cloth is used as the electrode. The cathode and anode are connected to the external circuit using titanium wire with a diameter of 0.5cm. The external resistance is 1000Ω. Use a parallel data collector to collect MFC voltage data.

Further specifically, in step 4, ultraviolet light is used as the energy source, the wavelength range of ultraviolet light is 200nm, the effective dose of ultraviolet light is not less than 20mJ/cm ² , and nano-TiO2 is used as a catalyst to degrade organic matter into carbon dioxide, water and other harmless substances. composition, so that the treated wastewater can meet the discharge standards.

Example

The wastewater in this embodiment is high-salt organic wastewater discharged from a pharmaceutical factory in Jiangsu. The treatment scale is: ^30m3 /d; the treatment method of the present invention is adopted: "regulating tank + pre-sedimentation oxidation tank + microalgae microbial fuel cell + UV photolysis oxidation pool".

High-salt organic wastewater first enters the regulating tank 1 to regulate water quality and quantity. Then it enters the pre-sedimentation oxidation tank 2, and passes through the gravel layer 2-2 and the iron-carbon micro-electrolysis filler layer 2-1 in sequence. This process can not only remove suspended particles in the water body, but also form large-volume flocs through intermolecular forces and electrostatic attraction. It carries some organic pollutants and inorganic ions for collaborative sedimentation and removal. At the same time, the dissolved state of the iron-based flocculant will adjust the pH of the water body, neutralize the alkaline water body to become acidic, and provide hydrolysis and acidification conditions for the subsequent anaerobic process. The effluent from the pre-sedimentation oxidation tank enters the microalgae microbial fuel cell 3. The anode chamber is inoculated with anaerobic sludge. The reaction matrix is high-salt organic wastewater. The pH value of the reaction matrix is 7.0-7.8, and the COD is 1200-1800 mg/L. , ammonia nitrogen is 280~420mg/L, phosphorus is 18~28mg/L, BG11 culture medium is used in the cathode chamber, microalgae are inoculated to produce oxygen as electron acceptors, and culture is carried out with 12 hours of light every day. The hydraulic retention time in the microbial fuel cell is 4 hours. This process can greatly improve the treatment efficiency of nitrogen, phosphorus and heavy metals, while realizing the conversion of chemical energy into electrical energy, degrading organic pollutants in sewage and recycling electrical energy. The dual purpose is to realize the energy conversion of wastewater. After being treated by the microalgae microbial fuel cell, the wastewater enters the UV photolysis oxidation tank 4. The UV photolysis oxidation tank is equipped with an ultraviolet radiation light source 4-1 and a return port 4-2. Water-immersed UV disinfection equipment is used, and part of the water flows through the reflux tank. Port 4-2 flows back to the cathode chamber 3 of the microalgae microbial fuel cell, and the effluent reaches the comprehensive secondary discharge standard for sewage.

The treatment results are as follows: Chemical oxygen demand (COD) dropped from 5000 to 32, biochemical oxygen demand (BOD) dropped from 1000 to 12, SS dropped from 300 to 18, total nitrogen (TN) dropped from 80 to 7, ammonia nitrogen ( NH3-N) dropped from 40 to 2, total phosphorus (TP) dropped from 7.5 to 0.3, and salinity dropped from 3.7% to 2.1%.

The above are the embodiments listed in this embodiment, but this embodiment is not limited to the above optional embodiments. Those skilled in the art can arbitrarily combine with each other according to the above methods to obtain other various embodiments. Anyone who has any experience in this embodiment can Various other forms of implementation may be derived under inspiration. The above-mentioned specific implementation modes should not be understood as limiting the protection scope of this embodiment. The protection scope of this embodiment should be defined in the claims, and the description can be used to interpret the claims.

Claims (5)

1. A new method for coupling microalgae-type microbial fuel cells to treat high-salt organic wastewater, which is characterized by including a conditioning tank, a pre-sedimentation oxidation tank, a microalgae-type microbial fuel cell, and a UV photolysis oxidation tank; In the first step S1, high-salt organic wastewater is input into the regulating tank to adjust water quality and quantity; In the second step S2, the pre-sedimentation oxidation tank is composed of a gravel layer and an iron-carbon micro-electrolysis filler layer from bottom to top; In the third step S3, it includes an anode chamber, a cathode chamber and a proton exchange membrane. The anode chamber and the cathode chamber are connected and the inner chambers are connected. The proton exchange membrane is arranged between the anode chamber and the cathode chamber. The anode chamber is equipped with an anode terminal reaction electrode. The anode wire is connected to the reaction electrode at the anode end. There is an anode cover plate on the top of the anode chamber. The anode cover plate has an anode top cover gas discharge and collection hole, a first outlet hole, a first reference electrode fixing hole and a first top inlet hole. Water inlet; the anode wire passes through the anode chamber from the first outlet hole. The structure of the cathode chamber is the same as that of the anode chamber. Both the anode chamber and the cathode chamber are filled with microbial fuel; In the fourth step s4, ultraviolet light is used as energy and nano-TiO2 is used as a catalyst to degrade organic matter into other harmless components such as carbon dioxide and water, so that the treated wastewater can be discharged up to standard. 2. A new method for coupling microalgae-type microbial fuel cells to treat high-salt organic wastewater according to claim 1. In the second step S2, the height of the gravel layer is 200-400 mm, and the iron-carbon micro-electrolysis filler layer The height is 300~600mm, preferably 500mm. 3. A new method for coupling microalgae-type microbial fuel cells to process high-salt organic wastewater according to claim 1. In the third step S3, the effective volumes of the anode chamber and the cathode chamber are both 2000 mL and are connected by flanges. , separated by a proton exchange membrane. Except for the feeding port and wire holes reserved on the upper cover of the device, the anode chamber is in a sealed state to ensure that it is in an anaerobic environment, and the cathode chamber is in a semi-sealed state to prevent the catholyte from evaporating too quickly. Carbon cloth is used as the electrode, and the cathode and anode are connected to the external circuit using titanium wire with a diameter of 0.5cm. The external resistance is 1000Ω. A parallel data acquisition instrument is used to collect MFC voltage data. 4. A new method for coupling treatment of high-salt organic wastewater with a microalgae-type microbial fuel cell according to claim 1. In the third step S3, BG11 culture medium is used in the cathode chamber and chlorella is inoculated. 5. A new method for coupling microalgae-type microbial fuel cells to process high-salt organic wastewater according to claim 1. In the fourth step s4, in the treated water treated by the ultraviolet oxidation device, hydrogen peroxide is increased, and the partially treated water is Water flows back to the cathode of the microalgae-type microbial fuel cell in S3, thereby promoting ion exchange within the microbial fuel cell.