Method and system for monitoring greenhouse gas emissions for a semi-covered wastewater treatment plant

Abstract

The present application provides a greenhouse gas emission monitoring method and system for a semi-covered sewage treatment plant, wherein the method comprises: determining a region I and a region II in the semi-covered sewage treatment plant; monitoring a first greenhouse gas emission amount in the region I by using an online monitoring method; monitoring a second greenhouse gas emission amount in the region II by using an unmanned aerial vehicle aerial survey method; determining a greenhouse gas emission monitoring result of the semi-covered sewage treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount; and outputting the greenhouse gas emission monitoring result. The greenhouse gas emission monitoring method and system for the semi-covered sewage treatment plant provide technical support for establishing a sky-ground integrated greenhouse gas monitoring system.

Description

Technical Field

[0001] This invention relates to the field of greenhouse gas emission monitoring technology, and in particular to a method and system for monitoring greenhouse gas emissions in semi-covered wastewater treatment plants. Background Technology

[0002] Climate change is a major global challenge facing humanity today. Strengthening greenhouse gas monitoring is crucial for coordinating efforts to address climate change and protect the environment. Identifying and assessing anthropogenic emissions and sinks of greenhouse gases (including methane, nitrous oxide, and fossil carbon dioxide) is the first step in developing effective strategies to mitigate climate change.

[0003] Methane (CH4) is a potent greenhouse gas, accounting for approximately 30% of global temperature rise since the Industrial Revolution. On a centennial timescale, methane has a warming potential 27.9 times that of carbon dioxide and 81.2 times on a 20-year timescale, with an atmospheric persistence of about 12 years. To achieve the goals of the Paris Agreement, significant reductions in methane emissions are needed globally by 2030. The total radiative forcing of methane from human activities is 0.54 ± 0.11 W / m², equivalent to about 16% of current atmospheric warming. With many countries committing to achieving net-zero carbon emissions within the next 20-30 years, reducing methane emissions has become a priority and is also one of the fastest ways to reduce overall greenhouse gas emissions.

[0004] Wastewater treatment is a major source of methane emissions, accounting for 5-8% of global anthropogenic methane emissions, after livestock farming (32%), oil and gas (25%), landfills (13%), and coal mining (11%). Methane is produced anaerobically during wastewater collection and treatment. Following anaerobic fermentation and acetone production, methanogenic archaea convert acetic acid, H2, or formic acid into methane and carbon dioxide. While many wastewater treatment plants promote methane production through anaerobic digestion to recover energy, uncontrolled emissions from wastewater networks and treatment systems remain a significant challenge. This is primarily due to the diffusive nature of CH4 and its susceptibility to variations influenced by factors such as process type, wastewater characteristics, and operating conditions. Furthermore, CH4 generated in one reactor may be released downstream, further complicating CH4 management. For example, CH4 generated in downstream activated sludge systems is often stripped from wastewater networks and primary sedimentation tanks during aeration. The CH4 released by anaerobic reactors such as upflow anaerobic sludge blanket reactors (UASB) or anaerobic membrane bioreactors (AnMBR) is mainly related to saturated or supersaturated dissolved CH4 in the effluent.

[0005] It is estimated that between 2006 and 2015, greenhouse gas emissions from wastewater treatment in my country (calculated based on the 100-year global warming potential) increased by 176% (from 41 Mt CO2e to 113 Mt CO2e). With the expansion of wastewater treatment plants and the annual increase in wastewater treatment volume, this emission figure shows a continued upward trend. It is projected that by 2030, total greenhouse gas emissions from wastewater will reach 3.65 Mt CO2e, accounting for 2.95% of the country's total greenhouse gas emissions, a figure that cannot be ignored. In the context of pollution reduction and carbon reduction, when methane is standardized to the amount of carbon dioxide reduction per ton, reducing CH4 is more cost-effective than reducing carbon dioxide. However, currently, most wastewater greenhouse gas emission data are based on model estimates and are mainly used as a reference for governments, departments, and institutions when formulating policies. Against this backdrop, accurate quantification-based control and reduction of wastewater greenhouse gas emissions is crucial to achieving greenhouse gas emission reduction targets.

[0006] In recent years, my country has continuously promoted the construction and renovation of urban sewage treatment plants, adhering to the principle of achieving environmentally friendly production for enterprises while avoiding pollution and damage to the local environment during the production process. In areas with limited land, densely populated areas, or environmentally sensitive areas, underground sewage treatment plants are generally adopted. Existing sewage treatment plants are usually upgraded by adding covers. Underground sewage treatment plants include fully underground and semi-underground types. A fully underground sewage treatment plant means that all sewage treatment structures are located underground, including the operating room and equipment maintenance access. This construction form offers good surface development and aesthetics, excellent overall airtightness, and minimal impact on the surrounding environment. However, it is generally more difficult and costly to construct, and has higher requirements for transportation, fire protection, ventilation, and lighting. Fully underground sewage treatment plants are likely to be the mainstream construction form for underground sewage treatment plants, integrating well with the environment and forming an organic combination with public spaces such as urban parks, sports fields, urban complexes, shopping malls, and offices. A semi-underground sewage treatment plant buries the water tank underground, with the operating layer and landscape layer exposed above ground. This type of construction involves shallower excavation, lower construction costs, and eliminates fire safety concerns, but it still requires a larger land area and demands higher standards for odor control and noise reduction. Representative semi-underground wastewater treatment plants include the Shenzhen Futian Wastewater Treatment Plant and the Tianjin East Suburb Wastewater Treatment Plant. Covering wastewater treatment plants involves covering various treatment tanks, such as sludge thickening tanks, primary sedimentation tanks, secondary sedimentation tanks, equalization tanks, aeration tanks, biological treatment tanks, reaction tanks, anaerobic tanks, and sludge oxidation ditches, with sealing materials used to enclose the tanks. The covered tanks appear as large domes, completely enclosing the wastewater and effectively collecting odorous gases. Generally, both semi-underground and covered wastewater treatment plants have some open-air treatment systems. For example, the Shenzhen Futian Wastewater Treatment Plant is a typical semi-underground plant, with its secondary sedimentation tank in the open. Another example is the Shenzhen Guangming Water Purification Plant, where most treatment tanks are covered, but the secondary sedimentation tank is not.

[0007] CH4 gas generated during wastewater collection and treatment is mainly emitted into the atmosphere through water-air interfaces and solid-gas interfaces, undergoing transport and diffusion. For wastewater treatment plants of the above types, CH4 concentration is typically detected at the exhaust outlet of the deodorization pipeline, and the CH4 greenhouse gas emissions are calculated by combining the exhaust pipeline airflow data. However, in semi-covered wastewater treatment plants, researchers generally only investigate the gas concentration in the deodorization pipeline, ignoring the open treatment tank; or they use the mass balance method to compare the total carbon concentration of the influent and effluent of this reaction tank to investigate the concentration of released methane and carbon dioxide; or they use flux chamber methods to detect the concentration of interfacial gases. Flux chambers can be used to investigate the emission patterns and fluxes of greenhouse gases within a small area; however, when these results are extended to the emissions of the entire plant area, the uncertainty of the conclusions often increases. In the past two years, UAV aerial surveying has received considerable attention. Simply put, it uses UAVs as carriers, employing airborne gas measuring instruments or in conjunction with real-time ground monitoring, to depict the greenhouse gas emissions of target sources at relatively high altitudes. Compared to other detection methods, using drones as a carrier to conduct greenhouse gas monitoring in a relatively small area (such as above an open sewage treatment reactor) is more feasible and repeatable.

[0008] Therefore, this patent proposes a scheme for monitoring and calculating CH4 greenhouse gas emissions from semi-covered wastewater treatment plants, providing technical support for establishing an integrated sky-ground greenhouse gas monitoring system. Summary of the Invention

[0009] This invention provides a method and system for monitoring greenhouse gas emissions from semi-covered wastewater treatment plants. The combined online monitoring and drone (UAV) approach facilitates the acquisition of overall greenhouse gas emission data for these plants. Generally, online monitoring can analyze covered, organized greenhouse gas emission points within the wastewater treatment plant, while drones are advantageous for exploring open, unorganized areas of emission. Furthermore, drones can explore areas that are normally inaccessible, such as those in semi-covered wastewater treatment plants where sampling ports are not provided at the exhaust vents after the deodorization device, or where the vents are too high for online monitoring instruments. In these cases, drones can be used to collect samples via hovering, enabling real-time monitoring and obtaining CH4 emission data at the corresponding exhaust vent of the treatment plant. This provides technical support for establishing an integrated air-ground greenhouse gas monitoring system.

[0010] This invention provides a method for monitoring greenhouse gas emissions from semi-covered wastewater treatment plants, comprising:

[0011] Identify Zone I and Zone II in a semi-covered wastewater treatment plant;

[0012] The first greenhouse gas emissions in region I were monitored using online monitoring methods.

[0013] The second greenhouse gas emissions in Region II were monitored using unmanned aerial vehicle (UAV) aerial surveying methods.

[0014] Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring results of the semi-covered wastewater treatment plant are determined;

[0015] Output the greenhouse gas emission monitoring results.

[0016] Preferably, determining Zone I and Zone II in a semi-covered wastewater treatment plant includes:

[0017] The wastewater treatment process area in the semi-covered wastewater treatment plant based on the coverage renovation and centralized deodorization of exhaust gas is designated as Area I;

[0018] The open wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area II.

[0019] Preferably, the method of monitoring the first greenhouse gas emissions within region I using online monitoring includes:

[0020] Insert the sampling tube of the online detection instrument into the gas sampling port at the straight pipe after the deodorization device in area I;

[0021] Activate the online detection instrument to put it into real-time gas concentration detection mode;

[0022] When the CH4 concentration data detected by the online detection instrument exceeds the upwind greenhouse gas background concentration and the detected CH4 concentration data is stable, the online detection instrument performs data reading for a preset duration every preset time interval. The data read includes: the difference between the greenhouse gas emission concentration at the gas sampling port and the upwind greenhouse gas background concentration, and the air volume at the total emission port after the deodorization device.

[0023] Based on the read data, the first greenhouse gas emission in region I is calculated using the following formula:

[0024]

[0025] Among them, Q I The first greenhouse gas emission within region I is composed of greenhouse gases emitted from i (i≥1) deodorization pipes. ΔC n,i q is the difference between the greenhouse gas emission concentration at the total exhaust outlet of the online monitoring instrument after the nth detection of the i-th deodorization device in area I and the background greenhouse gas concentration upwind. n,i The air volume at the total exhaust port after the online detection instrument performs its nth detection on the i-th deodorization device in area I. Let i be the average greenhouse gas emission of the i-th deodorizing exhaust pipe in the region I, where i is the maximum value of the total number of deodorizing pipes, and n is the maximum value of the total number of times the air volume at the total exhaust port after the i-th deodorizing device in the region I is detected using an online detection instrument.

[0026] Preferably, the method of using unmanned aerial vehicle (UAV) aerial surveying to monitor the second greenhouse gas emissions within region II includes:

[0027] Plan the flight path of the unmanned aerial vehicles (UAVs) within Area II;

[0028] Control the drone to start traveling along the drone's flight path at a preset flight speed, flight altitude, and number of cycles;

[0029] Acquire monitoring data from the drone, the monitoring data including:

[0030] Based on the monitoring data, the second greenhouse gas emissions in Region II are calculated using the following formula:

[0031]

[0032] Among them, Q II F represents the second greenhouse gas emissions within region II. j,m The greenhouse gas emission flux is obtained by the UAV during its j-th monitoring of the m-th open treatment pool in region II. The average greenhouse gas emissions of the m-th open treatment pond in Region II are denoted by j, where j is the maximum value of the total number of times the greenhouse gas emission flux of the m-th open treatment pond in Region II is monitored, and m is the maximum value of the total number of open treatment ponds.

[0033] Preferably, determining the greenhouse gas emission monitoring results of the semi-covered wastewater treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount includes:

[0034] Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring result is calculated using the following formula:

[0035] Q total =Q I +Q II

[0036] Among them, Q total For the greenhouse gas emission monitoring results, Q I Let Q be the first greenhouse gas emission. II This represents the second greenhouse gas emission.

[0037] This invention provides a greenhouse gas emission monitoring system for semi-covered wastewater treatment plants, comprising:

[0038] The first determination module is used to determine Zone I and Zone II in a semi-covered wastewater treatment plant;

[0039] The first monitoring module is used to monitor the first greenhouse gas emissions within the area I using an online monitoring method;

[0040] The second monitoring module is used to monitor the second greenhouse gas emissions within Area II using UAV aerial surveying.

[0041] The second determining module is used to determine the greenhouse gas emission monitoring results of the semi-covered sewage treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount.

[0042] The output module is used to output the greenhouse gas emission monitoring results.

[0043] Preferably, the first determining module determines Region I and Region II in the semi-covered wastewater treatment plant, including:

[0044] The covered wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area I.

[0045] The open wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area II.

[0046] Preferably, the first monitoring module uses an online monitoring method to monitor the first greenhouse gas emissions within region I, including:

[0047] The sampling tube of the online detection instrument is inserted into the gas sampling port at the straight section of the deodorization device in the deodorization exhaust pipeline within the area I.

[0048] Activate the online detection instrument to put it into real-time gas concentration detection mode;

[0049] When the CH4 concentration data detected by the online detection instrument exceeds the upwind greenhouse gas background concentration and the detected CH4 concentration data is stable, the online detection instrument continuously reads data for a preset duration at preset time intervals. The read data includes: the difference between the greenhouse gas emission concentration at the gas sampling port and the upwind greenhouse gas background concentration, and the air volume at the total emission port after the deodorization device.

[0050] Based on the read data, the first greenhouse gas emission in region I is calculated using the following formula:

[0051]

[0052] Among them, Q I The first greenhouse gas emission within region I, ΔC n,i q is the difference between the greenhouse gas emission concentration at the gas sampling port at the straight pipe of the deodorization device in the i-th deodorization exhaust pipe within region I, detected by the online detection instrument during the nth detection, and the upwind background greenhouse gas concentration. n,i The airflow at the total exhaust port after the deodorization device is detected by the online detection instrument during the nth detection of the i-th deodorization exhaust pipe in area I. Let i be the average greenhouse gas emission of the i-th deodorizing exhaust pipe in the region I, where i is the maximum value of the total number of deodorizing pipes, and n is the maximum value of the total number of times the air volume at the total exhaust port after the i-th deodorizing device in the region I is detected using an online detection instrument.

[0053] Preferably, the second monitoring module uses unmanned aerial vehicle (UAV) aerial surveying to monitor the second greenhouse gas emissions within region II, including:

[0054] Plan the flight path of the unmanned aerial vehicles (UAVs) within Area II;

[0055] Control the drone to start traveling along the drone's flight path at a preset flight speed, flight altitude, and number of cycles;

[0056] The monitoring data of the UAV is acquired, including: greenhouse gas concentration values ​​along the flight path and meteorological data (wind speed, wind direction, etc.);

[0057] Based on the monitoring data, the second greenhouse gas emissions in Region II are calculated using the following formula:

[0058]

[0059] Among them, Q II F represents the second greenhouse gas emissions within region II. j,m The greenhouse gas emission flux is obtained by the UAV during its j-th monitoring of the m-th open treatment pool in region II. The average greenhouse gas emissions of the m-th open treatment pond in Region II are denoted by j, where j is the maximum value of the total number of times the greenhouse gas emission flux of the m-th open treatment pond in Region II is monitored, and m is the maximum value of the total number of open treatment ponds.

[0060] Preferably, the second determining module determines the greenhouse gas emission monitoring results of the semi-covered wastewater treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, including:

[0061] Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring result is calculated using the following formula:

[0062] Q total =Q I +Q II

[0063] Among them, Q total For the greenhouse gas emission monitoring results, Q I Let Q be the first greenhouse gas emission. II This represents the second greenhouse gas emission.

[0064] Other features and advantages of the invention will be set forth in the following description, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention may be realized and obtained by means of the structures particularly pointed out in the written description, claims, and drawings.

[0065] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0066] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0067] Figure 1 This is a flowchart of a greenhouse gas emission monitoring method for a semi-covered wastewater treatment plant, as described in an embodiment of the present invention.

[0068] Figure 2 This is a schematic diagram illustrating the specific application of the technical solution in the embodiments of the present invention;

[0069] Figure 3 This is yet another schematic diagram illustrating the specific application of the technical solution in the embodiments of the present invention;

[0070] Figure 4 This is a schematic diagram of a greenhouse gas emission monitoring system for a semi-covered wastewater treatment plant, as described in an embodiment of the present invention. Detailed Implementation

[0071] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0072] It should be noted that in this patent, a wastewater treatment plant is defined as a fully covered wastewater treatment plant where the deodorization device (one or more sets) covers the entire wastewater treatment process and there are no open treatment pools; a wastewater treatment plant that has undergone deodorization modification in some treatment pools and is open in the remaining part is defined as a semi-covered wastewater treatment plant.

[0073] Major developed countries such as the United States, the European Union, and Japan have included greenhouse gases in their environmental regulations. my country has established separate accounting systems for pollutants and greenhouse gases. In 2023, the "Emission Reduction Assessment Standard for Urban Wastewater Treatment Plants" was released, specifying the assessment process for carbon emission reduction (i.e., greenhouse gas emission reduction) of existing wastewater treatment plants and the low-carbon design assessment process for new wastewater treatment plants, as well as the terms and definitions of carbon emissions and reductions, carbon accounting boundaries and methods, data acquisition, and assessment report preparation. Specifically, for direct greenhouse gas emission accounting, the main approach is to use activity data from the wastewater treatment plant, including treatment volume and influent and effluent pollutant concentrations, and to calculate greenhouse gases such as CH4 using the emission factor method. However, wastewater treatment plants with the necessary conditions are encouraged to use measurement methods to quantify emissions.

[0074] Existing greenhouse gas monitoring technologies include flux chamber-based online monitoring, ground-based remote sensing monitoring, and aircraft-based monitoring. Flux chamber-based online monitoring can monitor gas concentrations in odor treatment emission pipelines and open wastewater reaction tanks. It is worth noting that due to the limited coverage area of ​​the flux chamber, it can only investigate CH4 emissions in a relatively small area. When monitoring open treatment tanks, engineering parameters (such as area) need to be considered to calculate the total CH4 emissions for the entire reaction tank. However, due to significant differences in CH4 emissions at different points within the reaction tank, there is uncertainty in the overall data. Ground-based remote sensing-based integrated plant monitoring methods include tracer gas methods and open-path laser methods. The tracer gas method places tracer gas in the central area of ​​the emission source. During monitoring, the release of tracer gas is controlled, and the concentrations of the tracer gas and the target gas are monitored in motion downwind of the plant area. Combined with a meteorological model, the target gas emission flux data is calculated. The open-path laser method monitors the target gas concentration along an open path downwind of the plant area and obtains the target gas flux data using a meteorological model. For semi-covered wastewater treatment plants, integrated monitoring methods based on ground-based remote sensing are difficult to implement and costly. Compared to flux chamber-based online monitoring, it cannot obtain CH4 emission data for different treatment process areas, making it difficult to provide pollution reduction and carbon reduction suggestions based on processes and operational conditions. Integrated plant monitoring based on aircraft, including small aircraft monitoring and UAV monitoring, can visualize the CH4 emission distribution within the plant area and achieve large-scale monitoring in a short time. However, while aircraft monitoring covers a wide area, it is difficult to accurately identify and classify small and medium-sized emission sources during analysis. In recent years, UAV aerial surveying has received considerable attention. Simply put, it uses UAVs as carriers, employing airborne gas measuring instruments or collaborating with real-time ground monitoring to quantify greenhouse gas emissions from target sources at relatively high altitudes. Therefore, this patent proposes a CH4 greenhouse gas emission monitoring and calculation scheme for semi-covered wastewater treatment plants, namely a methane monitoring scheme combining online monitoring and UAV aerial surveying. The CH4 concentration in the odor treatment and emission pipeline was detected using online monitoring instruments, and the CH4 concentration in the open wastewater reaction tank was detected using drone aerial survey.

[0075] This invention provides a method for monitoring greenhouse gas emissions from semi-covered wastewater treatment plants, such as... Figure 1 As shown, it includes:

[0076] S1. Determine Zone I and Zone II in the semi-covered wastewater treatment plant;

[0077] S2. Monitor the first greenhouse gas emissions within region I using online monitoring methods;

[0078] S3. Use unmanned aerial vehicle (UAV) aerial surveying method to monitor the second greenhouse gas emissions in Area II;

[0079] S4. Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, determine the greenhouse gas emission monitoring results of the semi-covered sewage treatment plant;

[0080] S5. Output the greenhouse gas emission monitoring results.

[0081] The determination of Zone I and Zone II in the semi-covered wastewater treatment plant includes:

[0082] The covered wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area I.

[0083] The open wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area II.

[0084] The method of monitoring the first greenhouse gas emissions within region I using online monitoring includes:

[0085] The sampling tube of the online detection instrument is inserted into the gas sampling port at the straight section of the deodorization device in the deodorization exhaust pipeline within the area I.

[0086] Activate the online detection instrument to put it into real-time gas concentration detection mode;

[0087] When the CH4 concentration data detected by the online detection instrument exceeds the upwind greenhouse gas background concentration and the detected CH4 concentration data is stable, the online detection instrument continuously reads data for a preset duration at preset time intervals. The read data includes: the difference between the greenhouse gas emission concentration at the gas sampling port and the upwind greenhouse gas background concentration, and the air volume at the total emission port after the deodorization device.

[0088] Based on the read data, the first greenhouse gas emission in region I is calculated using the following formula:

[0089]

[0090] Among them, Q I The first greenhouse gas emission within region I, ΔC n,i q is the difference between the greenhouse gas emission concentration at the gas sampling port of the total exhaust outlet after the nth detection by the online monitoring instrument of the i-th deodorization device in area I and the background greenhouse gas concentration in the upwind direction. n,i The air volume at the total exhaust port after the online detection instrument performs its nth detection on the i-th deodorization device in area I. Let i be the average greenhouse gas emission of the i-th deodorizing exhaust pipe in the region I, where i is the maximum value of the total number of deodorizing pipes, and n is the maximum value of the total number of times the air volume at the total exhaust port after the i-th deodorizing device in the region I is detected using an online detection instrument.

[0091] The method of using unmanned aerial vehicle (UAV) aerial surveying to monitor the second greenhouse gas emissions in Region II includes:

[0092] Plan the flight path of the unmanned aerial vehicles (UAVs) within Area II;

[0093] Control the drone to start traveling along the drone's flight path at a preset flight speed, flight altitude, and number of cycles;

[0094] The monitoring data of the UAV is acquired, including: greenhouse gas concentration values ​​along the flight path and meteorological data (wind speed, wind direction, etc.);

[0095] Based on the monitoring data, the second greenhouse gas emissions in Region II are calculated using the following formula:

[0096]

[0097] Among them, Q II F represents the second greenhouse gas emissions within region II. j,m The greenhouse gas emission flux is obtained by the UAV during its j-th monitoring of the m-th open treatment pool in region II. The average greenhouse gas emissions of the m-th open treatment pond in Region II are denoted by j, where j is the maximum value of the total number of times the greenhouse gas emission flux of the m-th open treatment pond in Region II is monitored, and m is the maximum value of the total number of open treatment ponds.

[0098] The determination of greenhouse gas emission monitoring results for the semi-covered wastewater treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount includes:

[0099] Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring result is calculated using the following formula:

[0100] Q total =Q I +Q II

[0101] Among them, Q total For the greenhouse gas emission monitoring results, Q I Let Q be the first greenhouse gas emission. II This represents the second greenhouse gas emission.

[0102] like Figure 2 As shown, the specific application steps of the above technical solution are as follows:

[0103] Preliminary investigations identified the key treatment processes, odor control coverage areas, and open treatment tanks for semi-covered wastewater treatment plants. Generally, typical wastewater treatment processes include: primary treatment, which uses mechanical methods such as screens, sedimentation, or flotation to remove stones, sand, grease, and oils from wastewater; secondary treatment, typically biochemical treatment, where pollutants are degraded and converted into sludge by microorganisms; tertiary treatment, the advanced treatment of wastewater, including nutrient removal and disinfection using chlorination, ultraviolet radiation, or ozone technology; and sludge treatment, which involves thickening, anaerobic digestion, dewatering, and storage to remove carbon, nitrogen, phosphorus, solid matter, pathogens, and other components, reducing the volume of wastewater slurry and stabilizing its properties. Depending on the treatment objectives and water quality, some wastewater treatment plants may not include all of the above processes. On-site investigation of the covered or semi-underground wastewater treatment plant's deodorization process is conducted, including the actual layout and operation of the exhaust ductwork (including fresh air inlets, branch pipes, and overall discharge pipes), flow rate monitoring of the emitted gas, and key information such as the wastewater treatment process area covered by the deodorization system (Area I). ​​The open wastewater treatment process area (Area II) within the wastewater treatment plant is identified. Based on the survey information and the actual operation of the wastewater treatment plant, engineering parameters such as the exhaust duct airflow parameters (design airflow and actual airflow data) and the surface area of ​​the open treatment tank are obtained.

[0104] For Area I: During the same time period, under normal operating conditions of the treatment tank, greenhouse gas emission concentrations were measured in the deodorization exhaust pipeline using online monitoring instruments. Following the standards GB / T 16157-1996 "Determination of Particulate Matter and Sampling Methods for Gaseous Pollutants in Exhaust Gas from Stationary Sources" and HJ / T 397-2007 "Technical Specification for Monitoring Stationary Source Exhaust Gas," wastewater treatment plants typically install gas sampling ports at the straight sections of the pipelines before and after the deodorization device (avoiding bends and areas with abrupt changes in cross-section). Therefore, during actual testing, the sampling tube of the online monitoring instrument was inserted into the gas collection port after the deodorization device, placing the sampling tube as centrally as possible at the exhaust outlet. The online monitoring instrument remained in real-time gas concentration monitoring mode after startup. When the observed CH4 concentration exceeded the background concentration value and the data value was relatively stable, the time was recorded, and continuous online monitoring for 5 minutes was performed. After the first round of monitoring, a 10-minute time interval was set, followed by another 5-minute continuous online monitoring. This process was repeated four times, i.e., four consecutive 5-minute online monitoring sessions were performed within one hour.

[0105] While monitoring online, information such as air pressure and air volume of the blower and induced draft fan are recorded. Induced draft fan is generally part of the deodorization process, used for ventilation, cooling, and exhaust of waste gas. Blower fan is generally used in wastewater treatment processes that require increased gas pressure. Recording the values ​​of both facilitates the calculation of the amount of greenhouse gases generated in the final exhaust gas.

[0106] Calculate the average greenhouse gas emissions for Region I using the following formula:

[0107]

[0108] Among them, Q I The first greenhouse gas emission within region I, ΔC n,i q is the difference between the greenhouse gas emission concentration at the total exhaust outlet of the online monitoring instrument after the nth detection of the i-th deodorization device in area I and the background greenhouse gas concentration upwind. n,i The air volume at the total exhaust port after the online detection instrument performs its nth detection on the i-th deodorization device in area I. Let i be the average greenhouse gas emission of the i-th deodorizing exhaust pipe in the region I, where i is the maximum value of the total number of deodorizing pipes, and n is the maximum value of the total number of times the air volume at the total exhaust port after the i-th deodorizing device in the region I is detected using an online detection instrument.

[0109] For Area II: During the same time period, under normal operation of the open treatment ponds, greenhouse gas emission concentrations will be measured using an unmanned aerial vehicle (UAV) aerial survey system. Based on the actual conditions of Area II, a certified professional engineer will plan the UAV flight path. The flight area will cover the entire Area II, maintaining a uniform speed and altitude. Specifically, when using the UAV system to detect CH4 concentration in the space above Area II, the flight speed will be 1 m / s, and the onboard real-time monitoring system will record concentration, wind vector, and location data per second. At least three aerial surveys will be conducted on the treatment ponds in Area II. After completion, emission flux data will be obtained using the online real-time monitoring system.

[0110] The second greenhouse gas emissions within region II are calculated using the following formula:

[0111]

[0112] Among them, Q II F represents the second greenhouse gas emissions within region II. j,m The greenhouse gas emission flux is obtained by the UAV during its j-th monitoring of the m-th open treatment pool in region II. The average greenhouse gas emissions of the m-th open treatment pond in Region II are denoted by j, where j is the maximum value of the total number of times the greenhouse gas emission flux of the m-th open treatment pond in Region II is monitored, and m is the maximum value of the total number of open treatment ponds.

[0113] The greenhouse gas emissions Q from this wastewater treatment plant total =Q I +Q II .

[0114] For example, online monitoring was used for Area I. The effective range and accuracy of the online monitoring instrument were: measurement range 0-100 ppm, accuracy (1σ) 5-second signal average 0.25 ppb@2ppm, 1-second signal average 0.60 ppb@2ppm. During the preliminary experiment, the CH4 emission concentration in each reaction tank of Area I was obtained between 5178.35 and 29163.35 ppb. The upwind background CH4 concentration was 1953.83-2063.79 ppb. This confirmed that the online monitoring instrument could be effectively used in this wastewater treatment plant.

[0115] For Zone II, aerial surveys using unmanned aerial vehicles (UAVs) were conducted to detect CH4 emission concentrations. The effective methane measurement range of the UAV detection system was 1-15000 ppm. Zone II mainly consists of disinfection tanks and secondary sedimentation tanks. CH4 concentrations detected above the disinfection tanks were similar to the upwind background concentration. The secondary sedimentation tanks showed relatively significant CH4 emissions. Figure 3 As shown. Therefore, the secondary sedimentation tank in Zone II is the key target for CH4 monitoring.

[0116] Table 1 shows the greenhouse gas emissions from wastewater treatment plants monitored during the same period:

[0117]

[0118] Table 1

[0119] This application has achieved the following beneficial effects:

[0120] The combined online monitoring and drone-based detection scheme helps to obtain overall greenhouse gas emission data for semi-covered wastewater treatment plants. Drones can explore areas that are normally inaccessible. For example, in some semi-covered wastewater treatment plants, the exhaust outlet after the deodorization device does not have a sampling port, or the exhaust outlet is too high to be suitable for the installation of online monitoring instruments. Drone aerial surveying can be used to detect CH4 emission data at the corresponding exhaust outlet of the treatment tank by utilizing the hovering function of the drone. This provides technical support for the establishment of an integrated air-ground greenhouse gas monitoring system.

[0121] This invention provides a greenhouse gas emission monitoring system for semi-covered wastewater treatment plants, such as... Figure 4 As shown, it includes:

[0122] The first determining module 1 is used to determine Zone I and Zone II in a semi-covered wastewater treatment plant;

[0123] The first monitoring module 2 is used to monitor the first greenhouse gas emissions within the area I using an online monitoring method;

[0124] The second monitoring module 3 is used to monitor the second greenhouse gas emissions in the area II using UAV aerial surveying.

[0125] The second determining module 4 is used to determine the greenhouse gas emission monitoring results of the semi-covered sewage treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount.

[0126] Output module 5 is used to output the greenhouse gas emission monitoring results.

[0127] The first determining module 1 determines Region I and Region II in the semi-covered wastewater treatment plant, including:

[0128] The covered wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area I.

[0129] The open wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area II.

[0130] The first monitoring module 2 uses an online monitoring method to monitor the first greenhouse gas emissions within region I, including:

[0131] Insert the sampling tube of the online detection instrument into the gas sampling port at the straight pipe after the deodorization device in area I;

[0132] Activate the online detection instrument to put it into real-time gas concentration detection mode;

[0133] When the CH4 concentration data detected by the online detection instrument exceeds the upwind greenhouse gas background concentration and the detected CH4 concentration data is stable, the online detection instrument continuously reads data for a preset duration at preset time intervals. The read data includes: the difference between the greenhouse gas emission concentration at the gas sampling port and the upwind greenhouse gas background concentration, and the air volume at the total emission port after the deodorization device.

[0134] Based on the read data, the first greenhouse gas emission in region I is calculated using the following formula:

[0135]

[0136] Among them, Q IThe first greenhouse gas emission within region I, ΔC n,i q is the difference between the greenhouse gas emission concentration at the total exhaust outlet of the online monitoring instrument after the nth detection of the i-th deodorization device in area I and the background greenhouse gas concentration upwind. n,i The air volume at the total exhaust port after the online detection instrument performs its nth detection on the i-th deodorization device in area I. Let i be the average greenhouse gas emission of the i-th deodorizing exhaust pipe in the region I, where i is the maximum value of the total number of deodorizing pipes, and n is the maximum value of the total number of times the air volume at the total exhaust port after the i-th deodorizing device in the region I is detected using an online detection instrument.

[0137] The second monitoring module 3 uses UAV aerial surveying to monitor the second greenhouse gas emissions within region II, including:

[0138] Plan the flight path of the unmanned aerial vehicles (UAVs) within Area II;

[0139] Control the drone to start traveling along the drone's flight path at a preset flight speed, flight altitude, and number of cycles;

[0140] The monitoring data of the UAV is acquired, including: greenhouse gas concentration values ​​along the flight path and meteorological data (wind speed, wind direction, etc.);

[0141] Based on the monitoring data, the second greenhouse gas emissions in Region II are calculated using the following formula:

[0142]

[0143] Among them, Q II F represents the second greenhouse gas emissions within region II. j,m The greenhouse gas emission flux is obtained by the UAV during its j-th monitoring of the m-th open treatment pool in region II. The average greenhouse gas emissions of the m-th open treatment pond in Region II are denoted by j, where j is the maximum value of the total number of times the greenhouse gas emission flux of the m-th open treatment pond in Region II is monitored, and m is the maximum value of the total number of open treatment ponds.

[0144] The second determining module 4 determines the greenhouse gas emission monitoring results of the semi-covered wastewater treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, including:

[0145] Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring result is calculated using the following formula:

[0146] Q total =Q I +Q II

[0147] Among them, Q total For the greenhouse gas emission monitoring results, Q I Let Q be the first greenhouse gas emission. II This represents the second greenhouse gas emission.

[0148] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A method for monitoring greenhouse gas emissions from semi-covered wastewater treatment plants, characterized in that, include: Identify Zone I and Zone II in a semi-covered wastewater treatment plant; The first greenhouse gas emissions in region I were monitored using online monitoring methods. The second greenhouse gas emissions in Region II were monitored using unmanned aerial vehicle (UAV) aerial surveying methods. Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring results of the semi-covered wastewater treatment plant are determined; Output the greenhouse gas emission monitoring results; The method of monitoring the first greenhouse gas emissions within region I using online monitoring includes: Insert the sampling tube of the online detection instrument into the gas sampling port at the straight pipe of the exhaust pipe after the deodorization device in area I; Activate the online detection instrument to put it into real-time gas concentration detection mode; When the CH4 concentration data detected by the online detection instrument exceeds the upwind greenhouse gas background concentration and the detected CH4 concentration data is stable, the online detection instrument continuously reads data for a preset duration at preset time intervals. The read data includes: the difference between the greenhouse gas emission concentration at the gas sampling port and the upwind greenhouse gas background concentration, and the air volume at the exhaust port after the deodorization device. Based on the read data, the first greenhouse gas emission in region I is calculated using the following formula: in, The first greenhouse gas emission within the region I is composed of greenhouse gases emitted from i (i≥1) deodorization pipes; For the online detection instrument The first detection within region I The difference between the greenhouse gas emission concentration at the exhaust outlet after the deodorization device and the background greenhouse gas concentration upwind. For the online detection instrument The first detection within region I The air volume at the main exhaust port after each deodorization device For the region I, the first The average greenhouse gas emissions of each deodorized exhaust pipe, where the maximum value of i is the total number of deodorized pipes. The maximum value is the first value detected by an online detection instrument within region I. The total number of times the air volume at the total exhaust port after each deodorization device; The method of using unmanned aerial vehicle (UAV) aerial surveying to monitor the second greenhouse gas emissions in Region II includes: Plan the flight path of the unmanned aerial vehicles (UAVs) within Area II; Control the drone to start traveling along the drone's flight path at a preset flight speed, flight altitude, and number of cycles; Acquire monitoring data from the UAV, including: greenhouse gas concentration values ​​along the flight path and meteorological data; Based on the monitoring data, the second greenhouse gas emissions in Region II are calculated using the following formula: in, The second greenhouse gas emissions within region II. For the drone The second time within region II Greenhouse gas emission fluxes were obtained by monitoring an open treatment pond. For the region II, the first Average greenhouse gas emissions per open treatment pond The maximum value is the first value within region II. The total number of times greenhouse gas emission fluxes were monitored in an open treatment pond. The maximum value is the total number of open processing pools.

2. The greenhouse gas emission monitoring method for a semi-covered wastewater treatment plant as described in claim 1, characterized in that, The determination of Zone I and Zone II in the semi-covered wastewater treatment plant includes: The covered wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area I. The open wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area II.

3. The greenhouse gas emission monitoring method for a semi-covered wastewater treatment plant as described in claim 1, characterized in that, The determination of greenhouse gas emission monitoring results for the semi-covered wastewater treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount includes: Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring result is calculated using the following formula: in, The greenhouse gas emission monitoring results are as follows. This is the first greenhouse gas emission amount. This represents the second greenhouse gas emission.

4. A greenhouse gas emission monitoring system for semi-covered wastewater treatment plants, characterized in that, include: The first determination module is used to determine Zone I and Zone II in a semi-covered wastewater treatment plant; The first monitoring module is used to monitor the first greenhouse gas emissions within the area I using an online monitoring method; The second monitoring module is used to monitor the second greenhouse gas emissions within Area II using UAV aerial surveying. The second determining module is used to determine the greenhouse gas emission monitoring results of the semi-covered sewage treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount. The output module is used to output the greenhouse gas emission monitoring results; The first monitoring module uses an online monitoring method to monitor the first greenhouse gas emissions within region I, including: The sampling tube of the online detection instrument is inserted into the gas sampling port at the straight pipe of the exhaust pipe after each deodorization device in the area I. Activate the online detection instrument to put it into real-time gas concentration detection mode; When the CH4 concentration data detected by the online detection instrument exceeds the upwind greenhouse gas background concentration and the detected CH4 concentration data is stable, the online detection instrument is continuously read for a preset duration at preset time intervals. The read data includes: the difference between the greenhouse gas emission concentration at the gas sampling port and the upwind greenhouse gas background concentration, and the air volume at the total emission port after the deodorization device. Based on the read data, the first greenhouse gas emission in region I is calculated using the following formula: in, The first greenhouse gas emissions within region I consist of greenhouse gases emitted from i (i≥1) deodorization pipes. For the online detection instrument The first detection within region I The difference between the greenhouse gas emission concentration at the total exhaust outlet after each deodorization device and the background greenhouse gas concentration upwind. For the online detection instrument The first detection within region I The air volume at the main exhaust port after each deodorization device For the region I, the first The average greenhouse gas emissions of each deodorized exhaust pipe, where the maximum value of i is the total number of deodorized pipes. The maximum value is the first value detected by an online detection instrument within region I. The total number of times the air volume at the total exhaust port after each deodorization device; The second monitoring module uses unmanned aerial vehicle (UAV) aerial surveying to monitor the second greenhouse gas emissions within Region II, including: Plan the flight path of the unmanned aerial vehicles (UAVs) within Area II; Control the drone to start traveling along the drone's flight path at a preset flight speed, flight altitude, and number of cycles; Acquire monitoring data from the UAV, including: greenhouse gas concentration values ​​along the flight path and meteorological data; Based on the monitoring data, the second greenhouse gas emissions in Region II are calculated using the following formula: in, The second greenhouse gas emissions within region II. For the drone The second time within region II Greenhouse gas emission fluxes were obtained by monitoring an open treatment pond. For the region II, the first Average greenhouse gas emissions per open treatment pond The maximum value is the first value within region II. The total number of times greenhouse gas emission fluxes were monitored in an open treatment pond. The maximum value is the total number of open processing pools.

5. The greenhouse gas emission monitoring system for a semi-covered wastewater treatment plant as described in claim 4, characterized in that, The first determining module determines Zone I and Zone II in the semi-covered wastewater treatment plant, including: The wastewater treatment process area in the semi-covered wastewater treatment plant based on the coverage renovation and centralized deodorization of exhaust gas is designated as Area I; The open wastewater treatment process area in the semi-covered wastewater treatment plant is designated as Area II.

6. The greenhouse gas emission monitoring system for a semi-covered wastewater treatment plant as described in claim 4, characterized in that, The second determining module determines the greenhouse gas emission monitoring results of the semi-covered wastewater treatment plant based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, including: Based on the first greenhouse gas emission amount and the second greenhouse gas emission amount, the greenhouse gas emission monitoring result is calculated using the following formula: in, The greenhouse gas emission monitoring results are as follows. This is the first greenhouse gas emission amount. This represents the second greenhouse gas emission.

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