Landfill gas filtering equipment for domestic waste landfill

Abstract

The application provides landfill gas filtering equipment for domestic waste landfill. The filtering equipment comprises a filtering tank and an air extraction device. The filtering tank comprises a first sieve plate and an air inlet cavity and an air outlet cavity distributed on both sides of the first sieve plate. The air extraction device is in communication with the air inlet cavity and is used for extracting landfill gas produced by domestic waste to the filtering tank. A graphite phase carbon nitride / zinc oxide composite (g-C3N4 / ZnO) coating is coated on the side of the first sieve plate facing the air inlet cavity, a visible light emitter is installed on the air inlet cavity, and the visible light emitter is configured to emit visible light to irradiate the graphite phase carbon nitride / zinc oxide composite (g-C3N4 / ZnO) coating. The filtering equipment provided by the application can realize cleaning of biological membrane blockage on the sieve plate.

Description

Technical Field

[0001] This application relates to the field of waste treatment, and more specifically, to a landfill gas filtration device for municipal solid waste landfill. Background Technology

[0002] As global urbanization continues, the amount of municipal solid waste generated is increasing year by year. Landfilling, as a common disposal method, is widely used in many countries and regions. During the landfilling process, a byproduct gas, known as landfill gas, is naturally generated. Its main components include methane (CH4), carbon dioxide (CO2), hydrogen sulfide (H2S), impurities, and other trace organic and inorganic compounds.

[0003] Before landfill gas can be collected, stored, transported, and utilized for subsequent energy conversion (such as power generation, heating, or as a chemical raw material), it needs to be filtered. During the waste degradation process, the microbial activity in municipal solid waste produces sticky biofilms (such as extracellular polymeric substances, EPS), which, when combined with moisture, can clog the filter pores and are difficult to remove through conventional backflushing. Utility Model Content

[0004] This application provides a landfill gas filtration device for municipal solid waste landfill, which can clean the biofilm blockage on the screen plate.

[0005] Specifically, this application is implemented through the following technical solution: One aspect of this application provides a landfill gas filtration device for municipal solid waste landfill, including... A filter canister includes a first sieve plate, and the filter canister includes an air inlet chamber and an air outlet chamber distributed on both sides of the first sieve plate. An extraction device, which is connected to the air inlet chamber, is used to extract landfill gas produced from municipal solid waste into the filter tank. The first sieve plate is coated with a graphite phase carbon nitride / zinc oxide composite coating on the side facing the air inlet cavity. The air inlet cavity is equipped with a visible light emitter, which is configured to emit visible light that irradiates the graphite phase carbon nitride / zinc oxide composite coating.

[0006] Optionally, the filter canister includes a funnel section and a cylindrical section, the first sieve plate is placed horizontally in the cylindrical section, the wall of the funnel section and the first sieve plate form an air inlet cavity, and the visible light emitter is installed on the side wall of the funnel section.

[0007] Optionally, the visible light emitters are provided in multiples, and in a group, along the sidewall of the funnel section from the top edge to the bottom edge.

[0008] The optional visible light emitter includes multiple sets, which are spaced apart along the circumference of the funnel segment.

[0009] Optionally, a light-transmitting plate is installed between the multiple sets of visible light emitters and the first sieve plate. The light-transmitting plate is funnel-shaped and is used to allow ultraviolet light to pass through.

[0010] Optionally, the filtration device further includes a power supply device and a positive electrode device. The power supply device is electrically connected to the first sieve plate, and the positive electrode device is fixed in the air inlet chamber. An electric field is formed between the first sieve plate and the positive electrode device.

[0011] Optionally, the filtration device further includes a vibrator rigidly connected to the first sieve plate, the vibrator being used to drive the first sieve plate to vibrate.

[0012] Optionally, the air intake chamber further includes a hot air device and a humidity sensor. The hot air device is connected to the air intake chamber, and the humidity sensor is installed in the air intake chamber and electrically connected to the hot air device. The hot air device is configured to blow air onto the first sieve plate according to the humidity value detected by the humidity sensor.

[0013] Optionally, the filtration device further includes a second sieve plate and a third sieve plate disposed in the air outlet chamber, the second sieve plate including an activated carbon layer and the third sieve plate including an iron oxide layer.

[0014] This application provides a landfill gas filtration device for municipal solid waste landfills. Firstly, a graphite-phase carbon nitride / zinc oxide composite coating (g-C3N4 / ZnO) is coated onto a first sieve plate, and a visible light emitter is installed. Visible light emitted by the emitter illuminates the graphite-phase carbon nitride / zinc oxide composite coating (g-C3N4 / ZnO). Biofilm produced by microorganisms accumulates on the side of the first sieve plate facing the air inlet chamber, i.e., on the graphite-phase carbon nitride / zinc oxide composite coating (g-C3N4 / ZnO). Under visible light irradiation, the graphite-phase carbon nitride / zinc oxide composite coating (g-C3N4 / ZnO) undergoes a photocatalytic reaction with extracellular polymers, thereby degrading the gel-like substances attached to the first sieve plate. This facilitates the removal of the gel-like substances from the first sieve plate, thus cleaning the biofilm blockage on the sieve plate. Attached Figure Description

[0015] Figure 1 This is a schematic diagram of a filtration device shown in an exemplary embodiment of this application; Figure 2 This is a front view of a filtration device shown in an exemplary embodiment of this application; Figure 3 This is a side view of a filtration device shown in an exemplary embodiment of this application; Figure 4 This is a top view of a filtration device illustrated in an exemplary embodiment of this application; Figure 5 This is a cross-sectional view of the first sieve plate shown in an exemplary embodiment of this application.

[0016] Among them: 100, filter tank; 100a, funnel section; 100b, cylindrical section; 110, first sieve plate; 101, air inlet chamber; 102, air outlet chamber; 120, graphite phase carbon nitride / zinc oxide composite coating; 130, visible light emitter; 140, light-transmitting plate; 150, second sieve plate; 160, third sieve plate; 200, air extraction device; 300, positive electrode device; 400, vibrator; 510, hot air inlet pipe. Detailed Implementation

[0017] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to 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.

[0018] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movement of the components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0019] Please refer to Figure 1 and Figure 5 This application provides a landfill gas filtration device for municipal solid waste landfill, comprising a filter tank 100 and an extraction device 200. The filter tank 100 includes a first screen plate 110 and an air inlet chamber 101 and an air outlet chamber 102 distributed on both sides of the first screen plate 110. The extraction device 200 is connected to the air inlet chamber 101 and is used to extract landfill gas generated from municipal solid waste into the filter tank 100. The side of the first screen plate 110 facing the air inlet chamber 101 is coated with a graphite phase carbon nitride / zinc oxide composite coating 120 (g-C3N4 / ZnO). A visible light emitter 130 is installed in the air inlet chamber 101, and the visible light emitter 130 is configured to emit visible light that irradiates the graphite phase carbon nitride / zinc oxide composite coating 120 (g-C3N4 / ZnO).

[0020] Landfill gas from municipal solid waste contains methane (CH4), carbon dioxide (CO2), nitrogen (N2), and oxygen (O2), as well as solid impurities, microorganisms, and water vapor. Microorganisms such as methanogens and sulfate-reducing bacteria obtain energy by decomposing organic matter, during which they secrete extracellular polymeric substances (EPS). These EPS combine with water vapor in the landfill gas to form a gel-like biofilm. Over time, this accumulated biofilm clogs the sieve plates used for filtering landfill gas, affecting the filtration efficiency. In this application, a graphite-phase carbon nitride / zinc oxide composite coating 120 (g-C3N4 / ZnO) is first coated on the first sieve plate 110, and a visible light emitter 130 is installed on the air inlet side 101. The visible light emitted by the emitter 130 illuminates the graphite-phase carbon nitride / zinc oxide composite coating 120 (g-C3N4 / ZnO). The biofilm produced by microorganisms accumulates on the side of the first sieve plate 110 facing the air inlet chamber 101, specifically on the graphite-phase carbon nitride / zinc oxide composite coating 120 (g-C3N4 / ZnO). Under visible light irradiation, the graphite-phase carbon nitride / zinc oxide composite coating 120 (g-C3N4 / ZnO) undergoes a photocatalytic reaction with extracellular polymers, thereby degrading the gel-like substances attached to the first sieve plate 110. This facilitates the removal of the gel-like substances from the first sieve plate 110, thus cleaning the biofilm blockage on the sieve plate. The photocatalytic method for cleaning sieve plate blockage provided in this application avoids the mechanical wear caused by physical cleaning. Furthermore, ZnO can release Zn... ²⁺ It disrupts microbial cell membranes and reduces biofilm regeneration.

[0021] Combination Figure 2 , Figure 3 and Figure 4 In one embodiment, the filter tank 100 includes a funnel section 100a and a cylindrical section 100b. A first sieve plate 110 is horizontally placed on the cylindrical section 100b. The wall of the funnel section 100a and the first sieve plate 110 form an air inlet chamber 101. A visible light emitter 130 is installed on the side wall of the funnel section 100a. Because the side wall of the funnel section 100a is inclined, when the visible light emitter 130 emits light, the inclined side wall design prevents excessive obstruction of the light during propagation, allowing it to more directly cover a larger area of ​​the first sieve plate 110. Compared to a vertical wall structure, the inclined side wall of the funnel section 100a can guide the light to be more evenly distributed across the entire sieve plate surface, thereby increasing the area of ​​light irradiated onto the sieve plate. This not only enhances the efficiency of the photocatalytic reaction but also allows the biofilm on the sieve plate to be degraded more evenly, thus improving the cleaning effect and filtration performance of the sieve plate.

[0022] In one embodiment, multiple visible light emitters 130 are provided along the sidewall of the funnel section 100a from the top edge to the bottom edge, and are arranged in a group. The multiple visible light emitters 130 are arranged from top to bottom along the inclined sidewall of the funnel section 100a, allowing light to illuminate the first sieve plate 110 at different angles and directions. This increases the area of ​​direct light illumination on the first sieve plate 110, reduces the problem of blind spots, and improves the efficiency of the photocatalytic reaction.

[0023] In one embodiment, the visible light emitters 130 include multiple sets arranged at intervals along the circumference of the funnel section 100a. Furthermore, they can be arranged at equal intervals, which improves the uniformity and coverage of light irradiation in this embodiment. This arrangement ensures that light is uniformly irradiated onto the first sieve plate 110 from multiple directions, effectively avoiding uneven illumination and dead zones, and improving the efficiency and cleaning effect of the photocatalytic reaction.

[0024] In one specific embodiment, please refer to Figure 4 Multiple sets of visible light emitters 130 are distributed in a radiating pattern, and no visible light emitters 130 are installed at the air intake position of the air extraction device 200 to avoid the air intake pipe of the air extraction device 200.

[0025] In one embodiment, a light-transmitting plate 140 is installed between multiple sets of visible light emitters 130 and the first sieve plate 110. The light-transmitting plate 140 is funnel-shaped and is used to allow ultraviolet light to pass through. Its functions are twofold: first, to achieve light transmission, ensuring that ultraviolet light can effectively pass through and irradiate the first sieve plate 110, thus guaranteeing the photocatalytic reaction; and second, to prevent the detached biofilm from falling onto the visible light emitters 130, avoiding surface contamination that could affect luminescence. Simultaneously, the funnel-shaped design facilitates the sliding of the detached material along the light-transmitting plate 140, preventing blockage and maintaining stable system operation. Similarly, the light-transmitting plate 140 can have a notch at the air inlet position of the extraction device 200 to avoid obstructing the air inlet pipe of the extraction device 200.

[0026] In one embodiment, reference Figure 2The filtration device also includes a power supply (not shown in the figure) and a positive electrode device 300. The power supply is electrically connected to the first sieve plate 110, and the positive electrode device 300 is fixed in the air inlet chamber 101. An electric field is formed between the first sieve plate 110 and the positive electrode device 300. The power supply can make the first sieve plate 110 negatively charged, thereby forming an electric field line pointing from the positive electrode device 300 to the first sieve plate 110. The biofilm blocking the first sieve plate 110 contains a large number of dissociated acidic groups (such as -COO⁻, -PO4³⁻) and the negatively charged structure of the microorganisms themselves, making it negatively charged overall. Under the action of the electric field, the negatively charged biofilm will generate a force to peel off from the first sieve plate 110, weakening the adhesion between the biofilm and the first sieve plate 110. Therefore, this embodiment can further improve the cleaning effect on the first sieve plate 110.

[0027] In one embodiment, the filtration device further includes a vibrator 400, rigidly connected to the first screen plate 110, so that the vibration of the vibrator 400 can be directly and stably transmitted to the first screen plate 110. The vibrator 400 is used to drive the first screen plate 110 to vibrate. The rigid connection is usually achieved using fasteners such as bolts and screws or welding to ensure that the two are tightly connected and not easily loosened. This allows the first screen plate 110 to remove attached contaminants, such as dust, particulate matter, and biofilm, during vibration, preventing the first screen plate 110 from clogging and further improving the cleaning efficiency and filtration effect of the first screen plate 110.

[0028] In one embodiment, the air intake chamber 101 further includes a hot air device (not shown) and a humidity sensor (not shown). The hot air device is connected to the air intake chamber 101, and can be specifically connected via... Figures 1 to 3 The hot air inlet pipe 510 is connected. A humidity sensor is installed in the air inlet chamber 101 and electrically connected to the hot air device, specifically via a controller. The hot air device is configured to blow air onto the first screen plate 110 based on the humidity value detected by the humidity sensor. Because the waste contains a large amount of moisture produced by the decomposition of organic matter, coupled with the environmental conditions of the landfill, such as rainfall and leachate, the resulting landfill gas may have high humidity. When the humidity sensor detects that the humidity in the air inlet chamber 101 is too high, the hot air device can be turned on to introduce dry hot air into the air inlet chamber 101, reducing the humidity in the air inlet chamber 101. Low humidity can weaken the stability of the biofilm attachment screen plate.

[0029] In one embodiment, the filtration device further includes a second sieve plate 150 and a third sieve plate 160 disposed in the gas outlet chamber 102. The second sieve plate 150 includes an activated carbon layer, and the third sieve plate 160 includes an iron oxide layer. The second sieve plate 150 may employ a honeycomb activated carbon layer, which efficiently traps volatile organic compounds (VOCs, such as benzene compounds and halogenated hydrocarbons) and odor molecules (thiols and amines) in the landfill gas through physical adsorption and chemical bonding. The third sieve plate 160 contains an iron oxide layer, primarily used to remove hydrogen sulfide from the landfill gas. Iron oxide can chemically react with hydrogen sulfide, converting it into harmless sulfides or sulfates, thereby effectively reducing the hydrogen sulfide content and mitigating its adverse environmental impacts, such as reducing odors, preventing corrosion of pipes and equipment, and improving gas quality.

[0030] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A landfill gas filtration device for municipal solid waste landfill, characterized in that, include The filter canister (100) includes a first sieve plate (110), and the filter canister (100) includes an air inlet chamber (101) and an air outlet chamber (102) distributed on both sides of the first sieve plate (110). An air extraction device (200) is connected to the air inlet chamber (101) and is used to extract landfill gas produced from municipal solid waste into the filter tank (100). The first sieve plate (110) is coated with a graphite phase carbon nitride / zinc oxide composite coating (120) on the side facing the air inlet cavity (101), and a visible light emitter (130) is installed in the air inlet cavity (101), the visible light emitter (130) being configured to emit visible light that irradiates the graphite phase carbon nitride / zinc oxide composite coating (120).

2. The landfill gas filtration device for municipal solid waste landfill as described in claim 1, characterized in that, The filter tank (100) includes a funnel section (100a) and a cylindrical section (100b). The first sieve plate (110) is placed horizontally in the cylindrical section (100b). The wall of the funnel section (100a) and the first sieve plate (110) form an air inlet chamber (101). The visible light emitter (130) is installed on the side wall of the funnel section (100a).

3. The landfill gas filtration device for municipal solid waste landfill as described in claim 2, characterized in that, Along the sidewall of the funnel section (100a) from the top edge to the bottom edge, there are multiple visible light emitters (130), and they are arranged in a group.

4. The landfill gas filtration device for municipal solid waste landfill as described in claim 3, characterized in that, The visible light emitter (130) includes multiple sets, which are arranged at intervals along the circumference of the funnel section (100a).

5. The landfill gas filtration device for municipal solid waste landfill as described in claim 4, characterized in that, A light-transmitting plate (140) is installed between the multiple sets of visible light emitters (130) and the first sieve plate (110). The light-transmitting plate (140) is funnel-shaped and is used to allow ultraviolet light to pass through.

6. The landfill gas filtration device for municipal solid waste landfill as described in any one of claims 1 to 5, characterized in that, The filtration device also includes a power supply device and a positive electrode device (300). The power supply device is electrically connected to the first sieve plate (110), and the positive electrode device (300) is fixed in the air inlet chamber (101). An electric field is formed between the first sieve plate (110) and the positive electrode device (300).

7. The landfill gas filtration device for municipal solid waste landfill as described in any one of claims 1 to 5, characterized in that, The filtration device also includes a vibrator (400) which is rigidly connected to the first sieve plate (110) and the vibrator (400) is used to drive the first sieve plate (110) to vibrate.

8. The landfill gas filtration device for municipal solid waste landfill as described in any one of claims 1 to 5, characterized in that, The air intake chamber (101) also includes a hot air device and a humidity sensor. The hot air device is connected to the air intake chamber (101), and the humidity sensor is installed in the air intake chamber (101) and electrically connected to the hot air device. The hot air device is configured to blow air onto the first sieve plate (110) according to the humidity value detected by the humidity sensor.

9. The landfill gas filtration device for municipal solid waste landfill as described in any one of claims 1 to 5, characterized in that, The filtration device further includes a second sieve plate (150) and a third sieve plate (160) disposed in the air outlet chamber (102), the second sieve plate (150) including an activated carbon layer and the third sieve plate (160) including an iron oxide layer.

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