Single-chamber microbial fuel cell system for simultaneously treating water pollution and gas pollution and application of single-chamber microbial fuel cell system

Abstract

The invention discloses a single-chamber microbial fuel cell system capable of simultaneously treating water and gas pollution and application thereof, and belongs to the technical field of pollutant treatment and energy recovery, the single-chamber microbial fuel cell system comprises an anode anoxic zone positioned on the upper side and a cathode aerobic zone positioned on the lower side, a gas sampling port and a wastewater inlet are formed above the anode anoxic zone; the cathode aerobic zone is provided with a plurality of ventilation inlets and wastewater sampling ports; microbial carriers are arranged in the anode anoxic zone and the cathode aerobic zone, an anode microbial carrier is arranged in the anode anoxic zone, a cathode microbial carrier is arranged in the cathode aerobic zone, and the cathode microbial carrier is filled with a cathode current collector; the anode microbial carrier serves as an anode, the cathode microbial carrier serves as a cathode, and the anode and the cathode are connected through a titanium wire. The system provided by the invention is easy to control in construction and operation processes, mild in operation condition, strong in degradation capability and low in cost, can effectively solve the problem that the microbial fuel cell is difficult to synchronously treat water and gas pollution and multi-component pollution, and is beneficial to efficient synchronous resourceful treatment of multi-component and multi-phase pollutants in industrial emission.

Description

Technical Field

[0001] The invention belongs to the technical field of pollutant treatment and energy recovery, and specifically relates to a single-chamber microbial fuel cell system for simultaneously treating water and air pollution and an application thereof. Background Art

[0002] With the development of the times, the demand for industrial products is increasing. During the production of industrial products, a large amount of organic pollutants are discharged into the environment, causing serious pollution and having a serious impact on human health and the ecological environment.

[0003] Benzene-related pollutants, represented by benzene, toluene, xylene, aniline, etc., are common petroleum pollutants in industrial pollution. Exposure to benzene-related pollutants can cause short-term and long-term health effects. Short-term exposure is associated with digestive complications, skin, eye and throat irritation, and nervous system failure; while long-term exposure is associated with anemia and some chronic diseases, such as cancer.

[0004] Physical and chemical methods have significant treatment effects on benzene series, but they have disadvantages such as high cost, high energy consumption, large secondary pollution, and slow speed. Biological methods can utilize the metabolic process of microorganisms to degrade multi-component pollutants. Microorganisms degrade pollutants into carbon dioxide, water, and other small molecular biomass. Compared with physical or chemical methods, it has attracted widespread attention due to its advantages such as simple equipment, mild operating conditions, low cost, and environmental friendliness. However, conventional bioreactors cannot achieve energy recovery while degrading pollutants. Therefore, it is urgent to develop an economical and efficient new biodegradation method.

[0005] Microbial fuel cells can effectively treat organic pollutants in water and output electricity simultaneously; however, various factors limit the widespread application of microbial fuel cells. Due to the activity of anaerobic bacteria inside the anode chamber of microbial fuel cells, microbial fuel cells are difficult to remove organic pollutants in gases; limited by the selectivity of microorganisms for pollutants, the degradation ability of multi-component mixed pollutants is poor; the cathode catalyst (such as platinum carbon) of conventional microbial fuel cells is expensive and has a short lifespan, and the anode metal catalyst has poor biocompatibility and conductivity.

[0006] At present, there is no research on using an internal integrated biocathode to eliminate oxygen in waste gas and achieve simultaneous degradation of wastewater and waste gas. Summary of the invention

[0007] In view of the above problems existing in the prior art, the present invention provides a single-chamber microbial fuel cell system and its application for simultaneously treating water and air pollution. The system integrates the biocathode into the lower side of the anode chamber, and introduces benzene series waste gas from the bottom and benzene series waste water from the top. The biocathode on the lower side effectively consumes oxygen in the benzene series waste gas inside the anode chamber and at the inlet, thereby inhibiting the inhibitory effect of oxygen on the anaerobic microorganisms on the upper side, thereby effectively degrading organic waste water and waste gas, and efficiently generating electricity. The present invention regulates the air intake position of different pollutants, adjusts the degradation selectivity of the biocathode layer for different pollutants, and hierarchically domesticates cathode microorganisms with different degradation characteristics, and uses graphene-loaded nickel foam with excellent biocompatibility and conductivity as the anode electrode to achieve the synchronous degradation and energy recovery of multi-component pollutants by a single-chamber microbial fuel cell. The system construction and operation process of the present invention are easy to control, the operating conditions are mild, the degradation ability is strong, the cost is low, and it can effectively solve the problem that microbial fuel cells are difficult to simultaneously treat water, air pollution and multi-component pollution, which is conducive to the efficient and synchronous resource treatment of multi-component and multi-phase pollutants in industrial emissions.

[0008] The present invention is achieved through the following technical solutions:

[0009] A single-chamber microbial fuel cell system for simultaneously treating water and air pollution comprises an anode anoxic zone located on the upper side and a cathode aerobic zone located on the lower side, wherein a gas sampling port and a wastewater inlet are arranged above the anode anoxic zone, and a plurality of ventilation inlets and a wastewater sampling port are arranged in the cathode aerobic zone; microbial carriers are arranged in both the anode anoxic zone and the cathode aerobic zone, wherein an anode microbial carrier is arranged in the anode anoxic zone, and a cathode microbial carrier is arranged in the cathode aerobic zone, and a cathode current collector is filled in the cathode microbial carrier; the anode microbial carrier serves as an anode, and the cathode microbial carrier serves as a cathode, and the anode and the cathode are connected by a titanium wire.

[0010] Furthermore, the anode microorganism carrier is nickel foam loaded with graphene;

[0011] The cathode microorganism carrier is polyurethane foam.

[0012] Furthermore, the graphene-loaded nickel foam is soaked in an anaerobic domesticated bacterial solution before assembly; the polyurethane foam is soaked in dilute sulfuric acid with a mass concentration of 1-5% for 10-30 minutes before assembly, and the acid-treated polyurethane foam is soaked in an aerobic domesticated bacterial solution.

[0013] Furthermore, the thickness of the graphene-loaded nickel foam is 0.1-40 mm, the thickness of the polyurethane foam is 10-70 cm, and the density is 20-100 kg / m 3 ; The loading amount of graphene in the graphene-loaded nickel foam is 10-200 mg / g.

[0014] Furthermore, the cathode current collector is made of carbon cloth, which is a hydrophilic conductive carbon cloth with a resistance of 0-5 mΩ / cm 2 .

[0015] Furthermore, the preparation method of the anode microorganism carrier is as follows:

[0016] A1. In a quartz tube furnace at atmospheric pressure, in an atmosphere of argon (200-500 sccm) and hydrogen (100-200 sccm), the nickel foam is heated to 900-1000° C. within 30-50 minutes;

[0017] A2. Anneal for 10-30 minutes without changing the gas flow rate;

[0018] A3. Add methane (5 sccm) into the reaction tube for 5-15 min;

[0019] A4, cooling to room temperature under the protection of argon gas (200-500 sccm) to obtain nickel foam loaded with graphene;

[0020] A5. Soak the obtained graphene-loaded nickel foam in an anaerobic domesticated bacterial solution to finally obtain an anode microbial carrier.

[0021] On the other hand, the present invention also provides an application of a single-chamber microbial fuel cell system for simultaneously treating water and air pollution in treating multi-component mixed benzene pollutants.

[0022] Furthermore, the application includes the following contents:

[0023] After microorganisms are inoculated on the graphene-loaded nickel foam and polyurethane foam, benzene, toluene and xylene exhaust gases are introduced simultaneously through ventilation inlets at different heights, and mixed wastewater of benzene, toluene and xylene is introduced through the wastewater inlet at the top; the concentrations of wastewater and exhaust gas are determined by liquid chromatograph and gas chromatograph, and the output voltage of the system is recorded by a paperless recorder.

[0024] Further, the heights of the ventilation inlets at different heights are set to be 10-40 cm from the bottom.

[0025] Furthermore, the mixed benzene pollutants include mixed wastewater of benzene, toluene and xylene, with a concentration of 10-200 mg / L, and the concentration of benzene, toluene and xylene waste gas ranges from 10-4000 mg / m 3 .

[0026] Compared with the prior art, the advantages of the present invention are as follows:

[0027] The present invention proposes for the first time a single-chamber microbial fuel cell system for simultaneously treating water and air pollution. The system integrates a biological cathode into an anode chamber, effectively consumes oxygen in the exhaust gas introduced into the anode chamber, thereby simultaneously and effectively degrading benzene-related wastewater and exhaust gas, and efficiently generating electricity. The system also achieves classification and domestication of degrading microorganisms by regulating the degradation selectivity of the biological cathode layer for different pollutants, thereby efficiently degrading multi-component pollutants. Graphene-loaded nickel foam is used as a carrier for anode microorganisms, which improves the conductivity of the system while promoting microbial colonization. The system constructed by the present invention is low-cost, highly efficient, and highly sustainable, and achieves energy recovery while achieving synchronous degradation of multi-component pollutants. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following is a brief introduction to the drawings required for the specific embodiments or the description of the prior art. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn according to the actual scale.

[0029] Figure 1 This is a schematic structural diagram of a single-chamber microbial fuel cell system for simultaneously treating water and air pollution according to the present invention;

[0030] Figure 2 A schematic diagram of the removal efficiency of toluene in mixed exhaust gas by a single-chamber microbial fuel cell system that simultaneously treats water and air pollution;

[0031] Figure 3 A schematic diagram of the elimination ability of toluene in mixed exhaust gas by a single-chamber microbial fuel cell system for simultaneously treating water and air pollution;

[0032] Figure 4 This is a schematic diagram of the electricity production capacity of a single-chamber microbial fuel cell system that simultaneously treats water and air pollution using mixed wastewater of benzene, toluene and xylene as the carbon source. DETAILED DESCRIPTION

[0033] In order to clearly and completely describe the technical solution and its specific working process of the present invention, the specific implementation methods of the present invention are as follows in conjunction with the accompanying drawings of the specification:

[0034] Example 1

[0035] like Figure 1As shown, this embodiment provides a single-chamber microbial fuel cell system for simultaneously treating water and air pollution, including an anode anoxic zone located on the upper side and a cathode aerobic zone located on the lower side, a gas sampling port and a wastewater inlet are arranged above the anode anoxic zone, and a plurality of ventilation inlets and a wastewater sampling port are arranged in the cathode aerobic zone; microbial carriers are arranged in both the anode anoxic zone and the cathode aerobic zone, an anode microbial carrier is arranged in the anode anoxic zone, a cathode microbial carrier is arranged in the cathode aerobic zone, and a cathode current collector is filled in the cathode microbial carrier; the anode microbial carrier serves as an anode, and the cathode microbial carrier serves as a cathode, and the anode and the cathode are connected by a titanium wire.

[0036] The overall frame of the system is made of organic glass with a size of 20cm*20cm*50cm, high-density polyurethane foam treated with dilute sulfuric acid (20cm*20*cm*5cm, 20-100kg / m 3 ) and nickel foam loaded with graphene (4cm*4cm*0.1cm) are fixed on the lower and upper sides of the anode chamber respectively, and the gap is filled with conductive carbon cloth (20cm*20cm*0.5cm) as a current collector. The bacterial solution, nutrient solution and mixed wastewater of benzene, toluene and xylene are pumped into the anode chamber through a peristaltic pump. Benzene, toluene and xylene waste gases are introduced synchronously at different heights of the biological cathode layer (30cm, 20cm, 10cm) at a rate of 0-5L / min through an air pump. The system is as follows Figure 1 shown.

[0037] The preparation method of the anode microorganism carrier is as follows:

[0038] A1. In a quartz tube furnace at atmospheric pressure, in an atmosphere of argon (200-500 sccm) and hydrogen (100-200 sccm), the nickel foam is heated to 900-1000° C. within 30-50 minutes;

[0039] A2. Anneal for 10-30 minutes without changing the gas flow rate;

[0040] A3. Add methane (5 sccm) into the reaction tube for 5-15 min;

[0041] A4, cooling to room temperature under the protection of argon gas (200-500 sccm) to obtain nickel foam loaded with graphene;

[0042] A5. Soak the obtained graphene-loaded nickel foam in an anaerobic domesticated bacterial solution to finally obtain an anode microbial carrier.

[0043] Example 2

[0044] This embodiment provides an application of a single-chamber microbial fuel cell system for simultaneously treating water and air pollution in treating multi-component mixed pollutants (benzene, toluene, and xylene).

[0045] The application includes the following contents: after the microorganisms are enriched on the surface of the graphene-loaded nickel foam and polyurethane foam, low-concentration benzene, toluene, and xylene mixed wastewater (10-50 mg / L) is introduced from the top of the anode chamber, and low-concentration benzene, toluene, and xylene waste gas (10-300 mg / m 3 After a period of low-concentration acclimation, high-concentration wastewater (50-500 mg / L) and waste gas (300-4000 mg / m 3 ).

[0046] The degradation effect of the single-chamber microbial fuel cell system for simultaneously treating water and air pollution on waste gas: the pollutant concentration at the inlet and outlet was analyzed using a gas chromatograph GC-2010plus, and the removal efficiency and elimination capacity were calculated. The gas chromatography conditions were: the vaporization chamber temperature was set at 220°C; the initial temperature of the chromatographic column was 50°C, maintained for 5 minutes, and then increased to 240°C at a program heating rate of 5°C / min; the detector temperature was set at 280°C.

[0047] Removal efficiency (%) = (inlet concentration - outlet concentration) inlet concentration × 100%

[0048] Elimination capacity (g / m 3 h) = (intake air concentration - outlet air concentration) / intake air flow rate

[0049] The removal efficiency of toluene waste gas in the mixed gas by the single-chamber microbial fuel cell system for simultaneously treating water and air pollution is shown in FIG. Figure 2 Taking toluene as an example, Figure 2 It can be seen that the system shows excellent degradation ability for toluene. The toluene inlet concentration is lower than 1937.54 mg / m 3 When the removal efficiency exceeds 80%, the inlet concentration is 1398.91 mg / m 3 When the removal efficiency is the highest, it reaches 97.06%. The system still has a good removal ability for high-concentration toluene gas, and the toluene concentration is 3267.41 mg / m 3 The removal efficiency is 63.75%.

[0050] The single-chamber microbial fuel cell system for simultaneously treating water and air pollution has the ability to eliminate toluene waste gas in the mixed gas. Figure 3 .from Figure 3 It can be seen that the elimination capacity is generally increasing. The elimination capacity is 3267.41 mg / m 3 When the maximum value reaches 18.75g / m3 h, the removal efficiency at this time is 63.75%.

[0051] The power generation capacity of the single-chamber microbial fuel cell system for simultaneously treating water and air pollution is shown in the results. Figure 3 . The system is connected to a 1000Ω resistor and a paperless recorder through a wire. The paperless recorder is set to record the output voltage every 10 seconds. With 100mg / L mixed wastewater of toluene, ethylbenzene and xylene as the only carbon source at the anode of the system, the system shows excellent water pollution degradation ability. A power generation cycle of the system is about 8 days, and the maximum output voltage is 518mV, which shows that the system has excellent energy recovery ability. In any cycle, the system's stable power generation time exceeds 6 days.

[0052] The ability of the single-chamber microbial fuel cell system for simultaneously treating water and air pollution to treat multi-component gaseous pollutants is to introduce fixed concentrations of benzene, toluene and xylene gases (1000 mg / m 3 The system showed excellent degradation ability for multiple components, with an average degradation efficiency of 95.24% for benzene, 97.23% for toluene, and 92.16% for xylene.

[0053] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0054] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0055] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A single-chamber microbial fuel cell system for simultaneously treating water and air pollution, characterized in that: It includes an anode anoxic zone located on the upper side and a cathode aerobic zone located on the lower side, wherein a gas sampling port and a wastewater inlet are arranged above the anode anoxic zone, and the cathode aerobic zone is provided with multiple ventilation inlets and a wastewater sampling port; microbial carriers are arranged in both the anode anoxic zone and the cathode aerobic zone, wherein an anode microbial carrier is arranged in the anode anoxic zone, and a cathode microbial carrier is arranged in the cathode aerobic zone, and a cathode current collector is filled in the cathode microbial carrier; the anode microbial carrier serves as an anode, and the cathode microbial carrier serves as a cathode, and the anode and the cathode are connected by a titanium wire.

2. A single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 1, characterized in that: The anode microorganism carrier is nickel foam loaded with graphene; The cathode microorganism carrier is polyurethane foam.

3. A single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 2, characterized in that: The graphene-loaded nickel foam is soaked in an anaerobic domesticated bacterial solution before assembly; the polyurethane foam is soaked in dilute sulfuric acid with a mass concentration of 1-5% for 10-30 minutes before assembly, and the acid-treated polyurethane foam is soaked in an aerobic domesticated bacterial solution.

4. A single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 2, characterized in that: The thickness of graphene-loaded nickel foam is 0.1-40 mm, the thickness of polyurethane foam is 10-70 cm, and the density is 20-100 kg / m 3 ; The loading amount of graphene in the graphene-loaded nickel foam is 10-200 mg / g.

5. A single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 1, characterized in that: The cathode current collector is made of carbon cloth, which is a hydrophilic conductive carbon cloth with a resistance of 0-5 mΩ / cm 2 .

6. A single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 1, characterized in that: The preparation method of the anode microorganism carrier is as follows: A1. In a quartz tube furnace at atmospheric pressure, in an atmosphere of argon (200-500 sccm) and hydrogen (100-200 sccm), the nickel foam is heated to 900-1000° C. within 30-50 minutes; A2. Anneal for 10-30 minutes without changing the gas flow rate; A3. Add methane (5 sccm) into the reaction tube for 5-15 min; A4, cooling to room temperature under the protection of argon gas (200-500 sccm) to obtain nickel foam loaded with graphene; A5. Soak the obtained graphene-loaded nickel foam in an anaerobic domesticated bacterial solution to finally obtain an anode microbial carrier.

7. Use of the single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 1 in treating multi-component mixed benzene pollutants.

8. The use of a single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 7 in treating multi-component mixed benzene pollutants, characterized in that: The application includes the following: After microorganisms are inoculated on the graphene-loaded nickel foam and polyurethane foam, benzene, toluene and xylene exhaust gases are introduced simultaneously through ventilation inlets at different heights, and mixed wastewater of benzene, toluene and xylene is introduced through the wastewater inlet at the top; the concentrations of wastewater and exhaust gas are determined by liquid chromatograph and gas chromatograph, and the output voltage of the system is recorded by a paperless recorder.

9. Application of the single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 1 in treating multi-component mixed benzene pollutants, characterized in that: The heights of the ventilation inlets at different heights are set at 10-40 cm from the bottom.

10. Application of the single-chamber microbial fuel cell system for simultaneously treating water and air pollution as claimed in claim 1 in treating multi-component mixed benzene pollutants, characterized in that: Mixed benzene pollutants include mixed wastewater of benzene, toluene and xylene, with a concentration of 10-200 mg / L, and the concentration of benzene, toluene and xylene waste gas ranges from 10-4000 mg / m 3 .

Images