Evaluation method and system for net carbon emission of sewage treatment plant and electronic equipment

Abstract

The invention provides a sewage treatment plant net carbon emission evaluation method and system and electronic equipment. The evaluation method comprises the steps that operation data of a sewage treatment plant are acquired; calculating the carbon emission of the sewage treatment plant according to the operation data, the electric power emission factor, the process emission factor and the medicament emission factor; calculating the carbon compensation amount of the sewage treatment plant according to the operation data, the electric power discharge factor and the carbon sequestration factor; calculating to obtain net carbon emission according to the carbon emission and the carbon compensation amount; evaluating the sewage treatment plant according to the net carbon emission; by improving the accuracy of calculating the net carbon emission, the evaluation result of the net carbon emission of the sewage treatment plant is more accurate.

Description

Technical Field

[0001] The present disclosure relates to the technical field of wastewater biological treatment, and in particular to an evaluation method, system and electronic equipment for the net carbon emission of a sewage treatment plant. Background Art

[0002] Climate change caused by the increase of greenhouse gases is one of the most serious non-traditional security issues facing the world today, and it seriously threatens human survival and development. The sewage treatment industry has attracted widespread attention in the industry due to its characteristics of consuming a large amount of energy and emitting greenhouse gases during its operation. Accurately evaluating the carbon emission level of urban sewage treatment plants during the operation stage is a prerequisite for the sewage treatment industry to transform from high-carbon emissions to low-carbon emissions or even "zero-carbon" emissions. However, at this stage, there is still much room for improvement in the systematic evaluation of carbon emission levels in sewage treatment:

[0003] ① The carbon accounting inventory for sewage treatment needs to be further clarified. Since the CO2 directly emitted during sewage treatment is mostly believed to originate from the natural carbon cycle system, it is ignored in most accounting systems, and the carbon emission level of the sewage treatment process has not been accurately calculated.

[0004] ② The accounting of negative carbon emissions is not comprehensive. Relevant research on the accounting of negative carbon behaviors mainly focuses on the chemical energy recovered from sludge treatment and disposal outside the boundaries of sewage treatment plants. There is less attention paid to the accounting methods of negative carbon behaviors such as tail water utilization and energy recovery. However, the application of energy recovery measures such as water source heat pumps and distributed photovoltaic power generation in sewage treatment plants is increasing, and the demand for recycling tail water from sewage treatment plants is gradually emerging. However, the carbon emission reduction in this part has not been scientifically evaluated.

[0005] ③ The emission factor method is one of the simplest and most convenient methods for carbon emission accounting. However, previous studies generally lacked basic data on measured carbon emissions from sewage treatment, resulting in a wide range of emission factor values ​​and poor local adaptability. The accounting results are often quite different from the actual values.

[0006] ④ The carbon emission level of sewage treatment is affected by many objective factors such as the treatment scale of the sewage treatment plant and the influent conditions. Under normal circumstances, the greenhouse gas emission intensity of the sewage treatment plant is inversely proportional to the treatment scale, and is directly proportional to the influent organic pollutant concentration (including the increase in organic concentration caused by the addition of carbon sources), the nitrogen-containing pollutant concentration, the reduction of organic pollutants and the reduction of nitrogen-containing pollutants. However, the calculation results of the common sewage treatment carbon emission accounting methods are mostly calculated in terms of daily average carbon emissions (kgCO2 / d) or carbon emissions per ton of water (kgCO2 / m 3 ) as a single unit representation fails to fully reflect the carbon emission characteristics of sewage treatment plants. Summary of the invention

[0007] The technical problem to be solved by the present disclosure is to overcome the defect in the prior art that the net carbon emissions calculation is inaccurate which leads to inaccurate assessment of the net carbon emissions of a sewage treatment plant, and to provide an evaluation method, system and electronic equipment for the net carbon emissions of a sewage treatment plant.

[0008] The present invention solves the above technical problems through the following technical solutions:

[0009] In a first aspect, a method for evaluating net carbon emissions of a sewage treatment plant is provided, the method comprising the following steps:

[0010] Obtaining operational data of sewage treatment plants;

[0011] Calculating the carbon emissions of the sewage treatment plant based on the operating data, the electricity emission factor, the process emission factor and the pharmaceutical emission factor;

[0012] Calculate the carbon compensation amount of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon sequestration factor;

[0013] Calculate the net carbon emissions based on the carbon emissions and the carbon compensation amount;

[0014] The wastewater treatment plant is evaluated based on the net carbon emissions.

[0015] Optionally, the calculating the carbon emissions of the sewage treatment plant specifically includes:

[0016] Calculate direct carbon emissions of carbon dioxide, nitrous oxide and methane from fossil sources separately;

[0017] Calculate the indirect carbon emissions of carbon dioxide generated by electricity consumption and carbon dioxide generated by pharmaceutical consumption separately;

[0018] The carbon emissions of the sewage treatment plant are calculated according to the direct carbon emissions and the indirect carbon emissions.

[0019] Optionally, the direct carbon emissions of fossil carbon dioxide, nitrous oxide and methane are calculated separately, specifically including:

[0020] Calculate the direct carbon emissions of fossil carbon dioxide based on the carbon dioxide generated by the degradation of organic matter in the sewage treatment plant under aerobic conditions and the carbon dioxide emissions generated by endogenous respiration of microorganisms in the sewage treatment plant;

[0021] Direct carbon emissions of nitrous oxide according to the process emission factors of nitrous oxide corresponding to different processes;

[0022] The direct carbon emissions of methane are calculated based on the corresponding process emission factors of methane under different processes.

[0023] Optionally, the evaluation method further includes:

[0024] Calculating the proportion of carbon dioxide emissions from fossil sources based on the operating data;

[0025] The direct carbon emission of fossil carbon dioxide is calculated based on the carbon dioxide generated by the degradation of organic matter in the sewage treatment plant under aerobic conditions, the emission of carbon dioxide generated by endogenous respiration of microorganisms in the sewage treatment plant, and the emission ratio.

[0026] Optionally, the separately calculating the indirect carbon emissions of carbon dioxide generated by electricity consumption and carbon dioxide generated by agent consumption specifically includes:

[0027] Calculate the indirect carbon emissions of carbon dioxide generated by electricity consumption in the sewage treatment plant based on the electricity emission factor corresponding to the area where the sewage treatment plant is located;

[0028] The indirect carbon emissions of carbon dioxide generated by the consumption of corresponding agents are calculated based on different agent emission factors.

[0029] Optionally, the carbon compensation amount includes the carbon compensation amount corresponding to the carbon dioxide utilized by tail water regeneration, energy recovery and carbon sink carbon reduction behavior;

[0030] The calculating the carbon compensation amount of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon fixation factor specifically includes:

[0031] Calculate the carbon compensation amount of the carbon dioxide generated by the tail water regeneration according to the operation data and the electricity emission factor corresponding to the area where the sewage treatment plant is located;

[0032] Calculate the carbon compensation amount of carbon dioxide for energy recovery in the sewage treatment plant based on the operating data and the electricity emission factor corresponding to the area where the sewage treatment plant is located;

[0033] The carbon compensation amount of carbon dioxide corresponding to the carbon sink of the vegetation is calculated according to the operating data and different carbon fixation factors.

[0034] In a second aspect, a system for evaluating net carbon emissions of a sewage treatment plant is provided, the system comprising: a data acquisition module, a data processing module and a result evaluation module;

[0035] The data acquisition module is used to acquire the operation data of the sewage treatment plant;

[0036] The data processing module is used to calculate the carbon emissions of the sewage treatment plant according to the operation data, the electricity emission factor, the process emission factor and the reagent emission factor; calculate the carbon compensation of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon fixation factor; and calculate the net carbon emissions according to the carbon emissions and the carbon compensation;

[0037] The result evaluation module is used to evaluate the sewage treatment plant according to the net carbon emissions.

[0038] In a third aspect, an electronic device is provided, comprising a memory, a processor, and a computer program stored in the memory and used to run on the processor, wherein when the processor executes the computer program, the method for evaluating the net carbon emissions of a sewage treatment plant as described in the first aspect is implemented.

[0039] In a fourth aspect, a computer-readable storage medium is provided, on which a computer program is stored, and when the computer program is executed by a processor, the method for evaluating the net carbon emissions of a sewage treatment plant as described in the first aspect is implemented.

[0040] In a fifth aspect, a computer program product is provided, comprising a computer program, which, when executed by a processor, implements the method for evaluating the net carbon emissions of a sewage treatment plant as described in the first aspect.

[0041] On the basis of being in accordance with the common sense in the art, the above-mentioned optional conditions can be arbitrarily combined to obtain the preferred embodiments of the present disclosure.

[0042] The positive progressive effect of the present disclosure is that the carbon emissions and carbon compensation of the sewage treatment plant are calculated according to the operating data and various factors, and the net carbon emissions are calculated according to the carbon emissions and the carbon compensation. Since the electricity emission factor can reflect the level of carbon dioxide generated by electricity consumption in different regions, the process emission factor can reflect the level of nitrous oxide or methane produced under different processes, the agent emission factor can reflect the level of carbon dioxide generated by different agent consumption, and the carbon fixation factor can reflect the level of carbon dioxide absorption by different vegetation, therefore, by combining various factors to calculate the net carbon emissions, the accuracy of the net carbon emissions can be improved; and then the sewage treatment plant is evaluated according to the net carbon emissions, so that the evaluation result of the net carbon emissions of the sewage treatment plant is more accurate. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A flow chart of a method for evaluating net carbon emissions from a sewage treatment plant provided in Example 1 of the present disclosure;

[0044] Figure 2 A partial flow chart of a method for evaluating net carbon emissions from a sewage treatment plant provided in Example 1 of the present disclosure;

[0045] Figure 3 A partial flow chart of a method for evaluating net carbon emissions from a sewage treatment plant provided in Example 1 of the present disclosure;

[0046] Figure 4 A schematic diagram of a module of a system for evaluating net carbon emissions from a sewage treatment plant provided in Example 2 of the present disclosure;

[0047] Figure 5 A schematic diagram of the structure of an electronic device provided in Embodiment 3 of the present disclosure. DETAILED DESCRIPTION

[0048] The present disclosure is further described below by way of examples, but the present disclosure is not limited to the scope of the examples.

[0049] Prefixes such as "first" and "second" are used in the embodiments of the present disclosure only to distinguish different description objects, and have no limiting effect on the position, order, priority, quantity or content of the described objects. The use of prefixes such as ordinal numbers to distinguish description objects in the embodiments of the present disclosure does not constitute a limitation on the described objects. For the statement of the described objects, please refer to the description in the context of the claims or embodiments, and no unnecessary limitation should be constituted due to the use of such prefixes. In addition, in the description of the present embodiment, unless otherwise specified, the meaning of "plurality" is two or more.

[0050] Example 1

[0051] Figure 1 This is a flow chart of a method for evaluating the net carbon emissions of a sewage treatment plant provided in Example 1 of the present disclosure, wherein the evaluation method comprises the following steps:

[0052] S101. Obtain operation data of a sewage treatment plant.

[0053] In this embodiment, the operation data of the sewage treatment plant may include basic information and basic data of the sewage treatment plant, wherein the basic information may include the design scale of the sewage treatment plant and the information of the biological treatment pool, and the basic data may include data on the amount of treated water, water quality treatment, resource and energy consumption, and carbon compensation behavior. In a specific example, as shown in Table 1:

[0054] Table 1

[0055]

[0056]

[0057] S102. Calculate the carbon emissions of the sewage treatment plant based on the operating data, electricity emission factors, process emission factors, and chemical emission factors.

[0058] In this embodiment, by selecting more suitable electricity emission factors, process emission factors and reagent emission factors, and combining the operation data of the sewage treatment plant, the carbon emissions of the sewage treatment plant are calculated, recorded as E1, so that the calculation result of carbon emissions is more accurate. In an optional embodiment, the electricity emission factors in different regions are different. For example, Table 2 is a table of electricity emission factors in different regions:

[0059] Table 2

[0060]

[0061] In an optional embodiment, different agents have different agent emission factors. For example, Table 3 is a table of values ​​for different agent emission factors:

[0062] Table 3

[0063]

[0064]

[0065] S103. Calculate the carbon compensation amount of the sewage treatment plant according to the operating data, the electricity emission factor and the carbon fixation factor.

[0066] In this embodiment, various carbon reduction behaviors are included in the calculation process of carbon compensation, and the carbon compensation amount is calculated based on the operating data of the sewage treatment plant, the electricity emission factors in different regions, and the carbon sequestration factors of different vegetation types, which is recorded as E2.

[0067] In an optional embodiment, different vegetation types have different carbon fixation factors. For example, Table 4 is a table of carbon fixation factors for different vegetation types:

[0068] Table 4

[0069] Vegetation Type <![CDATA[Carbon sequestration factor [kgCO2 / (m 2 ·a)]]]> Trees (height greater than 6m) 27.5 Trees (2-6m in height) 22.2 Mixed planting of large and small trees 20.2 Bushes (about 1.25m high) 13.4 Bushes (about 0.85m high) 10.3 Bushes (about 0.55m high) 8.2 Grassland (height greater than 0.25m) 5.2 Grassland (less than 0.25m in height) 1.2 Mixed planting of trees, bushes and grass 0.4

[0070] S104. Calculate the net carbon emissions according to the carbon emissions and the carbon compensation amount.

[0071] In this embodiment, the net carbon emissions are calculated based on E1 and E2 obtained in the above steps. In a specific example, the net carbon emissions include the unit water net carbon emissions E t , Daily average net carbon emissions E d and the net carbon emission per unit of aerobic pollutants E H , the calculation formula is:

[0072] E t =E1-E2

[0073] Ed =E t ×Q

[0074] E H =E t ×1000÷X

[0075] Among them, Q is the average daily water treatment volume of the sewage treatment plant, m3 / d; X is the reduction of oxygen-consuming pollutants, mg / L.

[0076] In a specific example, the calculation formula of X is:

[0077] X=BOD 进 -BOD 出 +3.5×(TN 进 -TN 出 )

[0078] Among them, BOD 进 : Biochemical pool influent BOD5 concentration, mg / L, can be replaced by sewage plant influent concentration, BOD (Biochemical Oxygen Demand), BOD5 (five-day biochemical oxygen demand);

[0079] BOD 出 : BOD5 concentration of biochemical pool effluent, mg / L, can be replaced by the effluent concentration of sewage plant;

[0080] TN 进 : TN concentration of sewage plant influent, mg / L; TN 出 : TN concentration of sewage plant effluent, mg / L.

[0081] S105. Evaluate the sewage treatment plant according to the net carbon emissions.

[0082] In a specific example, based on the net carbon emissions per unit of wastewater E t , Net carbon emissions per unit of aerobic pollutants E H The sewage treatment plants are evaluated based on the three indicators of carbon reduction and negative carbon behavior, as shown in Table 5. The specific scoring standard is A=A1+A2+A3; among them, A is the total score of net carbon emission evaluation; A1 is the score of net carbon emission per unit sewage; A2 is the score of net carbon emission per unit aerobic pollutants; A3 is the score of carbon reduction and negative carbon behavior.

[0083] Table 5

[0084]

[0085]

[0086] The evaluation results of the sewage treatment plant are divided into three levels: "excellent", "good" and "qualified". When the total score A is greater than or equal to 85, the evaluation result of the sewage treatment plant is excellent; when the total score A is greater than or equal to 70 and less than 85, the evaluation result of the sewage treatment plant is good; when the total score A is greater than or equal to 30 and less than 70, the evaluation result of the sewage treatment plant is qualified, as shown in Table 6:

[0087] Table 6

[0088] Evaluation results Total evaluation score excellent A≥85 good 70≤A＜85 qualified 30≤A＜70

[0089] This embodiment calculates the carbon emissions and carbon compensation of the sewage treatment plant based on the operating data and various factors, and calculates the net carbon emissions based on the carbon emissions and the carbon compensation. The accuracy of the net carbon emissions is improved by improving the calculation method of the net carbon emissions. The sewage treatment plant is then evaluated based on the net carbon emissions, so that the evaluation result of the net carbon emissions of the sewage treatment plant is more accurate.

[0090] In an optional embodiment, Figure 2 As shown, the step S102 specifically includes:

[0091] S201, respectively calculate the direct carbon emissions of fossil carbon dioxide, nitrous oxide and methane. In this embodiment, the calculation formula for direct carbon emissions is:

[0092] E 11 =E 11CO2 +E 11N2O +E 11CH4

[0093] Among them, E 11 E is the direct carbon emissions of the sewage treatment plant, that is, the greenhouse gases directly emitted into the atmosphere due to the conversion of pollutants during the sewage treatment process; 11CO2 E is the direct carbon emission of fossil carbon dioxide, that is, the CO2 directly emitted into the atmosphere during the biological treatment of sewage to degrade organic pollutants; 11N2O is the direct carbon emission of nitrous oxide; E 11CH4 is the direct carbon emission of methane.

[0094] S202. Calculate the indirect carbon emissions of carbon dioxide generated by electricity consumption and carbon dioxide generated by agent consumption respectively.

[0095] In this embodiment, the calculation formula for indirect carbon emissions is:

[0096] E 12 =E 12电 +E 12药

[0097] Among them, E12 It is the indirect carbon emissions of the sewage treatment plant, that is, the carbon emissions generated by the energy or materials consumed in the sewage treatment process at its production site. The energy consumed is mainly the electricity consumed by the operation of aeration blowers, agitators, lifting pumps, sand-water separators, underwater flow thrusters, return pumps, scrapers, sludge dewatering equipment and other facilities in the sewage treatment process. The materials consumed mainly include carbon sources added when the C / N (carbon-nitrogen ratio) is insufficient, disinfectants added when sewage leaves the plant, and flocculants added when sludge is concentrated and dehydrated. Therefore, it can be divided into carbon dioxide generated by electricity consumption and carbon dioxide generated by chemical consumption. 12电 The carbon dioxide produced by electricity consumption, E 12药 Carbon dioxide produced by the consumption of medicine.

[0098] S203. Calculate the carbon emissions of the sewage treatment plant according to the direct carbon emissions and the indirect carbon emissions.

[0099] In this embodiment, the calculation formula for the carbon emissions of the sewage treatment plant is:

[0100] E1=E 11 +E 12

[0101] Among them, E1 is the carbon emission of the sewage treatment plant; E 11 is direct carbon emissions; E 12 Indirect carbon emissions.

[0102] In an optional embodiment, the step S201 specifically includes:

[0103] S301. Calculate the direct carbon emissions of fossil carbon dioxide based on the carbon dioxide generated by the degradation of organic matter in the sewage treatment plant under aerobic conditions and the carbon dioxide emissions generated by endogenous respiration of microorganisms in the sewage treatment plant.

[0104] In this embodiment, there are two ways to generate CO2 during sewage treatment: first, microbial metabolism degrades organic pollutants and synthesizes new cells, and organic matter is partially oxidized to CO2; second, microbial endogenous respiration generates CO2 by consuming organic matter in the body. Since most of the organic pollutants (i.e., BOD) in sewage are reduced in the aerobic reaction stage, in this embodiment, only the aerobic reaction stage is considered for the direct CO2 emission accounting.

[0105] In the biological treatment stage of sewage, organic matter in sewage is decomposed by microorganisms under aerobic conditions, which will directly cause CO2 emissions. According to the stoichiometric relationship, the CO2 emissions caused by aerobic degradation of organic matter can be calculated from the O2 consumption of the process, and the O2 consumption is the oxygen consumption of the aerobic degradation process of organic pollutants. Since part of the total oxygen consumption in the biological treatment system is used for aerobic degradation of organic matter, and part is used for the reproduction of microorganisms themselves. Therefore, the O2 consumption can be calculated from the BOD equivalent of the total amount of organic matter reduced in the influent and effluent during the biological treatment stage and the oxygen equivalent of the newly added microbial amount.

[0106] Therefore, according to the chemical reaction equation: 2C 10 H 19 O3N+25O2→20CO2+16H2O+2NH3 It can be seen that the calculation relationship between the carbon dioxide produced by degradation under aerobic conditions and the amount of oxygen consumed is:

[0107]

[0108] In a specific example, the carbon dioxide produced by the degradation of organic matter under aerobic conditions is calculated as:

[0109]

[0110] Among them, E 好氧降解CO2 : CO2 emissions from aerobic degradation of fossil organic pollutants, kg CO2 / m 3 ;

[0111] E O2 :Oxygen consumption in the aerobic degradation process of organic pollutants in biological treatment of unit sewage, kg O2 / m 3 ; The calculation formula is:

[0112] E O2 =[1.47×(BOD 进 -BOD 出 +BOD 外加 )-1.42×Y obs ×(BOD 进 -BOD 出 +BOD 外加 )]×10 -3

[0113] BOD 外加 =(0.77×M 甲醇 +0.8×M 葡萄糖 +0.52×M 乙酸钠 )÷Q×10 6

[0114] 1.47: Ratio of actual BOD concentration to detected BOD concentration;

[0115] 1.42 is the BOD equivalent of microbial cells, kg BOD / kg MLVSS;

[0116] Y obs : Activated sludge apparent yield coefficient, kg MLVSS / kg BOD; the calculation formula is:

[0117]

[0118] Y: activated sludge synthesis yield coefficient, kg MLVSS / kg BOD, ranging from 0.4 to 0.8, usually 0.68;

[0119] K d : Attenuation coefficient, i.e., the microbial self-oxidation rate, d -1 , usually 0.05;

[0120] SRT: average residence time of biosolids, d; its calculation formula is:

[0121]

[0122] V: effective volume of aeration tank, m 3 ;

[0123] MLSS: Average concentration of suspended solids in biological pool mixed liquor, mg / L; calculation formula:

[0124] M 干污泥 =M 污泥产量 ×(1-ρ)

[0125] M 干污泥 : The amount of absolutely dry sludge discharged from the sewage treatment plant every day, t / d;

[0126] M 污泥产量 : Daily sludge output of sewage treatment plant, t / d;

[0127] ρ: sludge moisture content, %;

[0128] BOD 进 : BOD5 concentration of biochemical pool influent, mg / L, can be replaced by the influent concentration of sewage plant;

[0129] BOD 出 : BOD5 concentration of biochemical pool effluent, mg / L, can be replaced by the effluent concentration of sewage plant;

[0130] BOD 外加 : BOD5 concentration increased by the additional carbon source added to the biochemical pond, mg / L;

[0131] Mmethanol: methanol consumption, t / d; Mglucose: glucose consumption, t / d; Msodium acetate: sodium acetate consumption, t / d;

[0132] Q: Average daily water volume treated by the sewage treatment plant, m 3 / d;

[0133] 0.77: Methanol converted to BOD equivalent; 0.8: Glucose converted to BOD equivalent; 0.52: Sodium acetate converted to BOD equivalent.

[0134] Secondly, microorganisms decompose their cytoplasm to produce carbon dioxide through endogenous respiration. The chemical reaction equation is: C5H7O2N+5O2→5CO2+2H2O+NH3. According to the stoichiometric relationship, the CO2 emissions caused by this process can be calculated from the mass of biomass degraded by endogenous respiration, and the mass of biomass degraded by endogenous respiration can be calculated from the total biomass mass of the biological treatment pool and the oxidation rate of the microorganisms themselves. Therefore, the calculation formula for the carbon dioxide emissions generated by endogenous respiration of microorganisms in sewage treatment plants is:

[0135]

[0136] M 降解生物质 =(V×MLVSS×K d )×10 -3

[0137] MLVSS=MLSS×θ

[0138] Among them, E 内源呼吸CO2 : Carbon dioxide emissions from endogenous respiration of microorganisms, kg CO2 / m 3 ;M 降解生物质 : The mass of biomass degraded by endogenous respiration of microorganisms, kg / d;

[0139] Q: Average daily water volume treated by the sewage treatment plant, m 3 / d; V: effective volume of aeration tank, m 3 ; MLVSS: average concentration of volatile suspended solids in the mixed liquor of the biological pool, mg / L; MLSS: average concentration of suspended solids in the mixed liquor of the biological pool, mg / L; θ: organic content of sludge, %.

[0140] S302. Calculate the direct carbon emissions of nitrous oxide according to the process emission factors of nitrous oxide corresponding to different processes.

[0141] In this embodiment, during the denitrification process of sewage treatment, the intermediate product N2O produced by incomplete nitrification and denitrification reactions is released into the atmosphere, resulting in direct N2O emissions. The process emission factors for producing N2O under different processes are different, resulting in differences in the direct carbon emissions of N2O. This application reduces the differences caused by different N2O emission levels under different processes by selecting different emission factors. The calculation formula is:

[0142] E 11N2O =[44 / 28×(TN 进 -TN 出 )×EF N2O ×10 -3 ]×265

[0143] Among them, E N2O : Direct carbon emissions from nitrous oxide emissions produced in nitrification and denitrification reactions, kg CO2 / m 3 ; 44 / 28: N2O to N2 molecular mass ratio; TN 进 : TN concentration of sewage plant influent, mg / L; TN 出 : TN concentration of sewage plant effluent, mg / L;

[0144] EF N2O : N2O emission factor in the biological treatment of sewage, kg N2O / kg N; the value can refer to the measured data. When there is no measured data, the AAO process (Anaerobic-Anoxic-Oxic) can be taken as 0.0046, the AO process (Anaerobic Oxic) can be taken as 0.0068, the oxidation ditch process can be taken as 0.0064, the SBR process (Sequencing Batch Reactor) can be taken as 0.0202, and the general value of other aerobic activated sludge treatment processes is 0.0106 (data source: "Technical Guidelines for Carbon Accounting and Emission Reduction Pathways for Urban Water Systems" and "Technical Specifications for Low-Carbon Operation Evaluation of Wastewater Treatment Plants"); 265: N2O global warming potential, kg CO2 / kg N2O.

[0145] S303. Calculate the direct carbon emissions of methane according to the process emission factors of methane corresponding to different processes.

[0146] In this embodiment, during the sewage treatment process, microorganisms metabolize organic pollutants in an anaerobic environment to produce CH4 that is discharged into the atmosphere, causing CH4 emissions. The process emission factors for producing CH4 under different processes are different, resulting in differences in the direct carbon emissions of CH4. This application reduces the differences caused by different CH4 emission levels under different processes by selecting different emission factors. The calculation formula is:

[0147] E CH4 =[(BOD 进 -BOD 出 )×EF CH4 ×10 -3 ]×28

[0148] Among them, E CH4 : Direct carbon emissions from methane emissions produced under anaerobic conditions, kg CO2 / m 3 EF CH4 : CH4 emission factor in biological wastewater treatment process, kg CH4 / kg BOD5; the value can refer to the measured data. When there is no measured data, the AAO process can take 0.0142, the AO process can take 0.0083, the oxidation ditch process can take 0.0096, the SBR process can take 0.0100, and the general value of other conventional activated sludge treatment processes is 0.0121 (data source: "Technical Guidelines for Carbon Accounting and Emission Reduction Pathways for Urban Water Systems" and "Technical Specifications for Low-Carbon Operation Evaluation of Wastewater Treatment Plants"); 28: N2O global warming potential, kg CO2 / kg CH4.

[0149] In an optional embodiment, Figure 3 As shown, the evaluation method further includes:

[0150] S401. Calculate the emission ratio of fossil carbon dioxide according to the operation data.

[0151] In this embodiment, since the total organic carbon content of organic pollutants in sewage from chemical products such as detergents accounts for 2.1% to 27.9%, it can cause 2.4% to 15.1% of direct CO2 emissions. The remaining directly emitted CO2 is regarded as originating from the natural carbon cycle system. Therefore, the emission ratio of fossil carbon dioxide is calculated at 10%, thereby calculating the direct carbon emissions of fossil carbon dioxide. In order to enhance the denitrification effect during sewage treatment, measures such as artificial addition of carbon sources are often taken. The CO2 generated by the degradation of this part of organic matter should all be included in the fossil CO2 emissions. The calculation formula for the emission ratio of fossil carbon dioxide is:

[0152]

[0153] Among them, FCF is the emission ratio of carbon dioxide from fossil sources, %.

[0154] S402. Calculate the direct carbon emission of fossil carbon dioxide based on the carbon dioxide generated by the degradation of organic matter in the sewage treatment plant under aerobic conditions, the emission of carbon dioxide generated by endogenous respiration of microorganisms in the sewage treatment plant, and the emission ratio.

[0155] In this embodiment, the formula for calculating the direct carbon emissions of carbon dioxide from fossil sources according to the emission ratio is:

[0156] E 11CO2 =FCF×(E 好氧降解Co2 +E 内源呼吸CO2 )

[0157] In an optional embodiment, the indirect carbon emissions of carbon dioxide generated by electricity consumption and carbon dioxide generated by agent consumption are calculated separately, specifically including:

[0158] S501. Calculate the indirect carbon emissions of carbon dioxide generated by electricity consumption in the sewage treatment plant according to the electricity emission factor corresponding to the area where the sewage treatment plant is located.

[0159] In this embodiment, the calculation formula for the indirect carbon emissions of carbon dioxide generated by electricity consumption is:

[0160] E 12电 =D×EF D ÷Q

[0161] Among them, E 12电 : Indirect carbon emissions from electricity consumption, kg CO2 / m 3 ; D: Power consumption per ton of water in the sewage treatment plant, kWh / m 3 EF D : Electricity emission factor, kgCO2 / kWh 。

[0162] S502. Calculate the indirect carbon emissions of carbon dioxide generated by the consumption of corresponding reagents according to different reagent emission factors.

[0163] In this embodiment, the calculation formula for the indirect carbon emissions of carbon dioxide generated by the consumption of the agent is:

[0164]

[0165] Among them, E 12药 : Indirect carbon emissions from the consumption of reagents, kg CO2 / m 3 ; n: a total of n medicines used; M Yi : Consumption of the i-th agent, t / d; EF Yi : Emission factor of the ith agent, kgCO2 / kg agent.

[0166] In an optional embodiment, the carbon compensation amount includes the carbon compensation amount corresponding to the carbon dioxide utilized in tail water regeneration, energy recovery and carbon reduction activities of carbon sinks.

[0167] In this embodiment, the calculation formula of the carbon compensation amount is:

[0168] E2=E 21 +E 22 +E 23

[0169] Among them, E2 is the carbon compensation amount; E 21 E is the carbon compensation amount of tail water regeneration; 22 Carbon offset for energy recovery; E 23 is the carbon compensation amount of carbon sink.

[0170] Step S103 specifically includes:

[0171] S601. Calculate the carbon compensation amount of the carbon dioxide generated by the tail water regeneration according to the operating data and the electricity emission factor corresponding to the area where the sewage treatment plant is located.

[0172] According to the principle of "high quality for high use, low quality for low use", the tail water of sewage treatment plants can be recycled for industrial water use, farmland irrigation, urban miscellaneous use, green space irrigation, environmental water use and other uses with relatively low water quality requirements. Among them, the four reuse methods of industrial water use, farmland irrigation, urban miscellaneous use and green space irrigation have all formed different degrees of tap water and water resource conservation, and formed different degrees of carbon compensation according to different application types, respective water quality standards and additional treatment requirements. The specific calculation formula is as follows:

[0173] E 21 =E 工业用水 +E 农田灌溉 +E 城市杂用 +E 绿地灌溉

[0174] Among them, E 21 : Carbon compensation amount of wastewater treatment plant tailwater regeneration, kgCO2 / m 3 ; E 工业用水 : Carbon compensation amount generated by industrial water use in sewage treatment plants, kgCO2 / m 3 ; E 农田灌溉 : Carbon compensation from farmland irrigation in sewage treatment plants, kgCO2 / m 3 ; E 城市杂用 : Carbon compensation amount generated by urban miscellaneous use of sewage treatment plants, kgCO2 / m 3 ; E 绿地灌溉 : Carbon compensation generated by green space irrigation in sewage treatment plants, kgCO2 / m 3 .

[0175] In this embodiment, the tail water that meets the treatment standards of the sewage treatment plant basically meets the water quality of industrial water, so it can be directly used for cooling water, washing water, boiler feed water, etc. The use of this part of recycled water is of great significance to the reduction of urban tap water consumption. The carbon compensation amount formed can be replaced by the carbon emissions of the water intake and water production process of the same amount of tap water. The specific calculation method is as follows:

[0176] E 工业用水 =(E 取水 +E 制水 )×Q 工业用水 ÷Q

[0177] E 取水 =W0×EF D

[0178] E 制水 =W×EF D +E 制水药耗

[0179] Among them, E 取水 : Carbon emissions from water intake at water supply plants, kgCO2 / m 3 ;

[0180] E 制水 : Carbon emissions from water production in water supply plants, kgCO2 / m 3 ;

[0181] Q 工业用水 : Average daily volume of tail water from sewage treatment plants reused as industrial water, m 3 / d; Q: Average daily water treatment volume of the sewage treatment plant, m 3 / d;

[0182] W0: water extraction energy intensity, kWh / m 3 ; Water intake energy intensity refers to the energy consumption per unit of water from the water source and transporting it to the water plant. It mainly comes from the water intake pump station or the water delivery pump station. Its value depends on the type of local water source. Combined with the literature survey on water intake energy consumption, the energy consumption of surface water intake is 0.12kWh / m 3 The energy consumption of water intake from the reservoir is 0.05kWh / m 3 , the energy consumption of groundwater extraction is 0.09kWh / m 3 ;

[0183] W: water production energy intensity, kWh / m 3 According to the 2018 Urban Water Supply Yearbook and the 2018 County and Town Water Supply Yearbook, the average electricity consumption of carbon emissions during the operation phase of the urban water supply system is 0.450 kWh / m 3 The average power consumption of the county and town water supply system during operation is 0.431 kWh / m 3 ;

[0184] EF D : Electricity emission factor, kgCO2 / kWh;

[0185] E 制水药耗 : Carbon emissions caused by the consumption of chemicals in the water production process of the water supply plant, kgCO2 / m 3 ; The drug consumption in the water supply system mainly includes coagulants (flocculants) and disinfectants. The main coagulants (flocculants) are generally inorganic substances such as polyaluminium chloride and polycopper sulfate, and the main disinfectants are chlorine-containing substances such as sodium hypochlorite. The consumption of the above-mentioned drugs mainly depends on the local water source conditions. Combined with the literature survey on drug consumption in the operation stage of urban water supply systems, according to the consumption of polyaluminium chloride as a coagulant of 3-100g / m 3 , Disinfectant Sodium Hypochlorite 1~3g / m 3 , and the values ​​of common chemical emission factors provided in Table 3, it is calculated that the carbon emission intensity caused by chemical consumption during the operation of the water supply system is about 0.0058-0.1649 kg CO2 / m 3 The specific value can be determined according to the local water source conditions and the treatment process of the water supply plant.

[0186] In this embodiment, the tail water of the sewage treatment plant can also be used for farmland irrigation. The calculation formula for the carbon compensation amount generated by farmland irrigation of the sewage treatment plant is:

[0187] E 农田灌溉 =E 取水 ×Q 农田灌溉 ÷Q

[0188] Among them, Q 农田灌溉 : Average daily volume of wastewater treatment plant tailwater recycled for farmland irrigation, m 3 / d; Q: Average daily water treatment volume of the sewage treatment plant, m 3 / d.

[0189] In this embodiment, the tail water of the sewage treatment plant can be used for urban greening, road cleaning, vehicle washing, construction and other purposes after additional disinfection. The use of this part of recycled water is of great significance to reducing the energy consumption of urban water resources. The carbon compensation amount formed can be replaced by the carbon emissions of the same amount of water intake, but the carbon emissions caused by additional treatment to meet the reuse standards must be included; therefore, the calculation formulas for the carbon compensation amount generated by urban miscellaneous use and green space irrigation are:

[0190] E 城市杂用 =)E 取水 +E 制水 -E 额外处理 )×Q 城市杂用 ÷Q

[0191] E 绿地灌溉 =(E 取水 +E制水 -E 额外处理 )×Q 绿地灌溉 ÷Q

[0192] Among them, E 额外处理 :In order to meet the recycled water quality standards, the sewage treatment plant conducts additional disinfection of tail water, which increases the carbon emissions caused by the consumption of disinfectants, kgCO2 / m 3 ;

[0193] Q 城市杂用 : Average daily volume of wastewater treatment plant tailwater recycled into urban miscellaneous water, m 3 / d;

[0194] Q 绿地灌溉 : Average daily water volume of sewage treatment plant tailwater recycled for green space irrigation, m 3 / d.

[0195] S602: Calculate the carbon compensation amount of carbon dioxide for energy recovery in the sewage treatment plant based on the operating data and the electricity emission factor corresponding to the area where the sewage treatment plant is located.

[0196] In this embodiment, the sewage treatment plant can recover carbon reduction through waste heat recovery, photovoltaic power generation and other methods to form carbon compensation. The calculation formula for the carbon compensation of carbon dioxide recovered by energy is:

[0197] E 22 =A×EF D ÷Q

[0198] Among them, EF D : Electricity emission factor, kgCO2 / kWh; A: Electricity recovery, kwh / d.

[0199] S603: Calculate the carbon compensation amount of carbon dioxide corresponding to the vegetation for carbon sink according to the operation data and different carbon fixation factors.

[0200] In this embodiment, the sewage treatment plant can plant biological nitrogen fixation by afforestation and ecological improvement, thereby forming a carbon compensation amount of carbon dioxide in the carbon sink, and the calculation formula is:

[0201]

[0202] Where n: a total of n different types of vegetation are used; A Zi : The area of ​​the i-th vegetation used in the ecological treatment process, m 2 EF Zi : Carbon fixation factor of the i-th vegetation used in the ecological treatment process, kgCO2 / (m 2 a).

[0203] Example 2

[0204] Corresponding to the aforementioned embodiment of the method for evaluating the net carbon emissions of a sewage treatment plant, the present disclosure also provides an embodiment of a system for evaluating the net carbon emissions of a sewage treatment plant.

[0205] Figure 4 A schematic diagram of a module of a system for evaluating net carbon emissions of a sewage treatment plant provided in Example 2 of the present disclosure, the system 700 includes: a data acquisition module 701, a data processing module 702 and a result evaluation module 703;

[0206] The data acquisition module is used to acquire the operation data of the sewage treatment plant;

[0207] The data processing module is used to calculate the carbon emissions of the sewage treatment plant according to the operation data, the electricity emission factor, the process emission factor and the reagent emission factor; calculate the carbon compensation of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon fixation factor; and calculate the net carbon emissions according to the carbon emissions and the carbon compensation;

[0208] The result evaluation module is used to evaluate the sewage treatment plant according to the net carbon emissions.

[0209] As for the system embodiment, since it basically corresponds to the method embodiment, the relevant parts can refer to the partial description of the method embodiment. The system embodiment described above is only illustrative, wherein the units described as separate components may or may not be physically separated, and the components as units may or may not be physical units, that is, they may be located in one place, or they may be distributed on multiple network units. Some or all of the modules may be selected according to actual needs to achieve the purpose of the disclosed solution.

[0210] Example 3

[0211] Figure 5 This is a schematic diagram of the structure of an electronic device shown in an example embodiment of the present disclosure, the electronic device includes a memory, a processor, and a computer program stored in the memory and used to run on the processor, and when the processor executes the computer program, the risk assessment method for buildings around a foundation pit described in any of the above embodiments is implemented. Figure 5 The electronic device 80 shown is only an example and should not bring any limitation to the functions and scope of use of the embodiments of the present disclosure.

[0212] like Figure 5As shown, the electronic device 80 may be in the form of a general-purpose computing device, for example, it may be a server device. The components of the electronic device 80 may include, but are not limited to: at least one processor 81, at least one memory 82, and a bus 83 connecting different system components (including the memory 82 and the processor 81).

[0213] The bus 83 includes a data bus, an address bus, and a control bus.

[0214] The memory 82 may include a volatile memory, such as a random access memory (RAM) 821 and / or a cache memory 822 , and may further include a read-only memory (ROM) 823 .

[0215] The memory 82 may also include a program tool 825 (or utility) having a set (at least one) of program modules 824, such program modules 824 including but not limited to: an operating system, one or more application programs, other program modules, and program data, each of which or some combination may include an implementation of a network environment.

[0216] The processor 81 executes various functional applications and data processing by running the computer programs stored in the memory 82, such as the risk assessment method for buildings around the foundation pit provided in Example 1.

[0217] The electronic device 80 may also communicate with one or more external devices 84 (e.g., keyboards, pointing devices, etc.). Such communication may be performed via an input / output (I / O) interface 85. Furthermore, the electronic device 80 may also communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter 86. As shown, the network adapter 86 communicates with other modules of the electronic device 80 via a bus 83. It should be understood that, although not shown in the figure, other hardware and / or software modules may be used in conjunction with the electronic device 80, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID (disk array) systems, tape drives, and data backup storage systems, etc.

[0218] It should be noted that although several units / modules or sub-units / modules of the electronic device are mentioned in the above detailed description, this division is merely exemplary and not mandatory. In fact, according to the embodiments of the present disclosure, the features and functions of two or more units / modules described above can be embodied in one unit / module. Conversely, the features and functions of one unit / module described above can be further divided into multiple units / modules to be embodied.

[0219] Example 4

[0220] The present disclosure also provides a computer-readable storage medium having a computer program stored thereon. When the program is executed by a processor, the method for evaluating the net carbon emissions of a sewage treatment plant provided in the above-mentioned embodiment 1 is implemented.

[0221] The readable storage medium may include but is not limited to: a portable disk, a hard disk, a random access memory, a read-only memory, an erasable programmable read-only memory, an optical storage device, a magnetic storage device or any suitable combination of the above.

[0222] Example 5

[0223] The present disclosure also provides a computer program product, including a computer program, which, when executed by a processor, implements the method for evaluating the net carbon emissions of a sewage treatment plant described in the above-mentioned embodiment 1.

[0224] Among them, the program code for executing the computer program product of the present disclosure can be written in any combination of one or more programming languages, and the program code can be executed completely on the user device, partially on the user device, as an independent software package, partially on the user device and partially on a remote device, or completely on the remote device.

[0225] Although the specific embodiments of the present disclosure are described above, those skilled in the art should understand that this is only an example, and the protection scope of the present disclosure is defined by the appended claims. Those skilled in the art may make various changes or modifications to these embodiments without departing from the principles and essence of the present disclosure, but these changes and modifications all fall within the protection scope of the present disclosure.

Claims

1. A method for evaluating net carbon emissions from a sewage treatment plant, characterized in that: The evaluation method comprises the following steps: Obtaining operational data of sewage treatment plants; Calculating the carbon emissions of the sewage treatment plant based on the operating data, electricity emission factors, process emission factors, and pharmaceutical emission factors; Calculate the carbon compensation amount of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon sequestration factor; Calculate the net carbon emissions based on the carbon emissions and the carbon compensation amount; The wastewater treatment plant is evaluated based on the net carbon emissions.

2. The evaluation method according to claim 1, characterized in that: The calculating of the carbon emissions of the sewage treatment plant specifically includes: Calculate direct carbon emissions of carbon dioxide, nitrous oxide and methane from fossil sources separately; Calculate the indirect carbon emissions of carbon dioxide generated by electricity consumption and carbon dioxide generated by pharmaceutical consumption separately; The carbon emissions of the sewage treatment plant are calculated according to the direct carbon emissions and the indirect carbon emissions.

3. The evaluation method according to claim 2, characterized in that: The direct carbon emissions of fossil carbon dioxide, nitrous oxide and methane are calculated separately, specifically including: Calculate the direct carbon emissions of fossil carbon dioxide based on the carbon dioxide generated by the degradation of organic matter in the sewage treatment plant under aerobic conditions and the carbon dioxide emissions generated by endogenous respiration of microorganisms in the sewage treatment plant; Calculate the direct carbon emissions of nitrous oxide based on the process emission factors of nitrous oxide corresponding to different processes; The direct carbon emissions of methane are calculated based on the corresponding process emission factors of methane under different processes.

4. The evaluation method according to claim 3, characterized in that: The evaluation method further comprises: Calculating the proportion of carbon dioxide emissions from fossil sources based on the operating data; The direct carbon emission of fossil carbon dioxide is calculated based on the carbon dioxide generated by the degradation of organic matter in the sewage treatment plant under aerobic conditions, the emission of carbon dioxide generated by endogenous respiration of microorganisms in the sewage treatment plant, and the emission ratio.

5. The evaluation method according to claim 2, characterized in that: The indirect carbon emissions of carbon dioxide generated by electricity consumption and carbon dioxide generated by agent consumption are calculated separately, specifically including: Calculate the indirect carbon emissions of carbon dioxide generated by electricity consumption in the sewage treatment plant based on the electricity emission factor corresponding to the area where the sewage treatment plant is located; The indirect carbon emissions of carbon dioxide generated by the consumption of corresponding agents are calculated based on different agent emission factors.

6. The evaluation method according to claim 1, wherein: The carbon compensation amount includes the carbon compensation amount corresponding to the carbon dioxide utilized in tail water regeneration, energy recovery and carbon sink carbon reduction behavior; The calculating the carbon compensation amount of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon fixation factor specifically includes: Calculate the carbon compensation amount of the carbon dioxide generated by the tail water regeneration according to the operation data and the electricity emission factor corresponding to the area where the sewage treatment plant is located; Calculate the carbon compensation amount of carbon dioxide for energy recovery in the sewage treatment plant based on the operating data and the electricity emission factor corresponding to the area where the sewage treatment plant is located; The carbon compensation amount of carbon dioxide corresponding to the carbon sink of the vegetation is calculated according to the operating data and different carbon fixation factors.

7. An evaluation system for net carbon emissions from a sewage treatment plant, characterized in that: The evaluation system includes: a data acquisition module, a data processing module and a result evaluation module; The data acquisition module is used to acquire the operation data of the sewage treatment plant; The data processing module is used to calculate the carbon emissions of the sewage treatment plant according to the operation data, the electricity emission factor, the process emission factor and the reagent emission factor; calculate the carbon compensation of the sewage treatment plant according to the operation data, the electricity emission factor and the carbon fixation factor; and calculate the net carbon emissions according to the carbon emissions and the carbon compensation; The result evaluation module is used to evaluate the sewage treatment plant according to the net carbon emissions.

8. An electronic device comprising a memory, a processor, and a computer program stored in the memory and used to run on the processor, characterized in that: When the processor executes the computer program, the method for evaluating the net carbon emissions of a sewage treatment plant according to any one of claims 1 to 6 is implemented.

9. A computer-readable storage medium having a computer program stored thereon, characterized in that: When the computer program is executed by a processor, the method for evaluating the net carbon emissions of a sewage treatment plant according to any one of claims 1 to 6 is implemented.

10. A computer program product, comprising a computer program, characterized in that When the computer program is executed by a processor, the method for evaluating the net carbon emissions of a sewage treatment plant according to any one of claims 1 to 6 is implemented.

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