Method for constructing scientific carbon target and low-carbon development path of sewage plant

Abstract

The invention relates to the technical field of water affairs, and discloses a method for constructing a scientific carbon target and a low-carbon development path of a sewage plant. The method comprises the following steps: accounting the carbon emission intensity of a sewage treatment plant in a reference year, comparing the carbon emission intensity with an average value and an optimal value of a sewage treatment industry to determine the relative level of the sewage treatment plant in the industry, and setting a preliminary scientific carbon target based on a top-down method; a sewage treatment plant low-carbon technology list is constructed, and comprehensive quantitative analysis is carried out from carbon reduction, economy and technology; and constructing a low-carbon development path planning model, inputting the preliminarily set scientific carbon target into the low-carbon development path planning model, verifying the rationality of the model, adjusting the model to a final scientific carbon target, and generating a low-carbon development path at the same time. The method provided by the invention can reasonably construct a scientific carbon target and a low-carbon development path of a sewage treatment plant.

Description

Technical Field

[0001] The present invention relates to the field of water technology, and in particular to a method for constructing a scientific carbon target and a low-carbon development path for a sewage treatment plant. Background Art

[0002] In recent years, the carbon emissions from sewage treatment plants have continued to grow. On the one hand, this is due to the continuous improvement of sewage treatment standards under the background of water shortage, and on the other hand, it is directly related to the high-energy consumption deep treatment process currently used. How to build a scientific carbon reduction target system and a popular low-carbon technology path has become a key technical bottleneck restricting the green transformation of the industry.

[0003] In existing research, the scientific carbon target setting of the water industry usually adopts scenario analysis to determine the carbon target by constructing a low-carbon development path. This bottom-up carbon target setting method often fails to fully tap the potential of sewage treatment plants in reducing carbon emissions, resulting in limited actual emission reduction effects.

[0004] In the planning of low-carbon development paths, existing research focuses on case analysis in specific scenarios. Such low-carbon development paths often rely too much on expert experience and lack the support of quantitative decision-making models. At the same time, the constructed low-carbon paths lack wide applicability. Summary of the invention

[0005] The purpose of the present invention is to solve the following problems: How to build scientific carbon targets and low-carbon development paths for sewage treatment plants based on the carbon reduction benefits, economic benefits and technological maturity of low-carbon technical measures in sewage treatment plants.

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides a method for constructing a scientific carbon target and a low-carbon development path for a sewage treatment plant, the method comprising the following steps: (1) Calculate the carbon emission intensity of the sewage treatment plant in the base year and compare it with the average and optimal values ​​of sewage treatment plants across the country to determine the relative level of the sewage treatment plant in the industry, and then set a preliminary science-based carbon target based on a top-down approach; (2) Through literature analysis and field research, a list of low-carbon technical measures for sewage treatment plants is constructed from the aspects of equipment energy saving, process improvement, intelligent control, energy recovery, and resource recycling; (3) Based on the actual operation data of the sewage treatment plant in the base year, combined with the carbon reduction benefit, economic benefit and technology maturity analysis methods, quantify the low-carbon technical measures list of the sewage treatment plant to obtain the quantitative results of the low-carbon technical measures list in the target year; Based on the actual operation data of the sewage treatment plant in the base year, considering only the change of the electricity factor, calculate the carbon emissions of the sewage treatment plant in the target year; then input the set "preliminary scientific carbon target" into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target" and adjust it to the final scientific carbon target, and generate a low-carbon development path at the same time.

[0007] The method provided by the present invention has at least the following beneficial effects: (1)The method provided by the present invention can reasonably construct the scientific carbon target and low-carbon development path of the sewage treatment plant.

[0008] (2)The method of the present invention can help the sewage treatment plant clarify the scientific carbon target and low-carbon development path, effectively respond to the challenges of climate change, and promote the low-carbon transformation of the sewage treatment industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a schematic flow chart of constructing the scientific carbon target and low-carbon development path of the sewage treatment plant in the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] In the ranges disclosed herein, the endpoints and any values are not limited to the exact ranges or values, and these ranges or values should be understood to include values close to these ranges or values. For numerical ranges, the endpoint values of each range, between the endpoint values of each range and a single point value, and between single point values can be combined with each other to obtain one or more new numerical ranges, and these numerical ranges should be regarded as specifically disclosed herein.

[0011] In the present invention, "A 2 O + MBR" represents anaerobic-anoxic-aerobic + membrane bioreactor.

[0012] As described above, the first aspect of the present invention provides a method for constructing the scientific carbon target and low-carbon development path of a sewage treatment plant, and the method includes the following steps: (1)Account for the carbon emission intensity of the sewage treatment plant in the base year, and compare it with the average value and the optimal value of the national sewage treatment plants to determine the relative level of the sewage treatment plant in the industry, and thus set a preliminary scientific carbon target based on the top-down method; (2)Through literature analysis and field research, construct a list of low-carbon technology measures for the sewage treatment plant from aspects such as equipment energy conservation, process improvement, intelligent control, energy recovery, and resource recycling; (3)Based on the actual operation data of the sewage treatment plant in the base year, combined with the carbon reduction benefit, economic benefit, and technology maturity analysis methods, quantify the list of low-carbon technology measures of the sewage treatment plant to obtain the quantification result of the list of low-carbon technology measures in the target year; (4)Based on the actual operation data of the sewage treatment plant in the base year, considering only the change of the electricity factor, calculate the carbon emissions of the sewage treatment plant in the target year; then input the set "preliminary scientific carbon target" into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target" and adjust it to the final scientific carbon target, and generate a low-carbon development path at the same time.

[0013] In the present invention, according to the "Technical Guidelines for Carbon Accounting and Emission Reduction Paths of Urban Water Service Systems", the greenhouse gas emissions of sewage treatment plants can be divided into Scope 1, Scope 2, and Scope 3. Among them, Scope 1 is the emissions of methane and nitrous oxide in structures such as pretreatment, biological treatment, secondary sedimentation tank, advanced treatment, sludge thickening, and sludge dewatering and drying during the operation of the sewage treatment plant, as well as the contribution value of carbon sinks within the plant boundary to carbon emissions; Scope 2 is the energy consumption-related carbon emissions generated from purchased heat, electricity, etc. during the operation of the sewage treatment plant; Scope 3 is the carbon emissions generated from the waste produced during the operation of the sewage treatment plant, the building materials during the construction process, the chemicals used in the sewage treatment plant, and the transportation of waste, building materials, and chemicals.

[0014] Among them, according to the formulas in the "Technical Guidelines for Carbon Accounting and Emission Reduction Paths of Urban Water Service Systems", calculate the carbon emissions of the sewage treatment system for the carbon emission inventories of Scope 1, Scope 2, and Scope 3. The specific calculation formulas are as follows: ; In the formula: ——Total carbon emissions of the sewage treatment system (kg CO2e); ——Methane carbon dioxide emission equivalent of the sewage treatment system (kg CO2e); ——Nitrous oxide carbon dioxide emission equivalent of the sewage treatment system (kgCO2e); ——Energy consumption carbon dioxide emission equivalent of the sewage treatment system (kg CO2e); ——Chemical consumption carbon dioxide emission equivalent of the sewage treatment system (kg CO2e); ——Methane carbon dioxide emission equivalent discharged into the receiving water body (kg CO2e); ——Nitrous oxide carbon dioxide emission equivalent discharged into the receiving water body (kg CO2e).

[0015] According to the "Technical Guidelines for Carbon Accounting and Emission Reduction Paths of Urban Water Service Systems", calculate the total carbon emissions of the sewage treatment system for the Scope 1 carbon emission inventory: ; ; In the formula, Q: The treatment water volume of the sewage treatment system, m 3 ; : Influent BOD concentration of the sewage treatment system (mg / L); : CH4 emission factor of the sewage treatment unit, kg CH4 / kg BOD; : Global warming potential value of CH4, take 28; : Influent TN concentration of the sewage treatment system, mg / L; : N2O emission factor of the sewage treatment unit, kg N2O-N / kg N; : Global warming potential value of nitrous oxide, take 265.

[0016] According to the "Technical Guide for Carbon Accounting and Emission Reduction Paths in Urban Water Systems", the total carbon emissions of the sewage treatment system are calculated for Scope 2 carbon emission inventory: ; In the formula, : Power consumption during the operation stage of the sewage treatment system, kW·h; : Carbon emission factor for electricity consumption, kgCO2 / kWh; : Global warming potential value of carbon dioxide, take 1.

[0017] According to the "Technical Guide for Carbon Accounting and Emission Reduction Paths in Urban Water Systems", the total carbon emissions of the sewage treatment system are calculated for Scope 3 carbon emission inventory: ; In the formula, : Consumption of the i-th type of reagent, kg; : CO2 emission factor of the i-th type of reagent, kg CO2-eq / kg; ; ; In the formula, : Effluent BOD concentration of the sewage treatment system, mg / L; : CH4 emission factor of the receiving water body, kgCH4 / kg BOD; : Effluent TN concentration of the sewage treatment system, mg / L; : N2O emission factor of the receiving water body, kg N2O-N / kg N.

[0018] In the present invention, the calculation formula for the carbon emission intensity of the sewage treatment plant in the base year is as follows: ; In the formula, : Annual carbon emission intensity of the sewage treatment plant, kg CO2e / m 3 ; : Total annual carbon emissions of the sewage treatment plant, kgCO2e; : Total annual water treatment volume of the sewage treatment plant, m 3 .

[0019] Preferably, in step (1), the carbon emission intensity of the sewage treatment plant in the base year is compared with the average and optimal values of the national sewage treatment plants to determine the relative level of the sewage treatment plant in the industry, and a preliminary scientific carbon target is set based on the top-down method, including: ; ; In the formula, x is the gap from the average value, %; y is the gap from the optimal value, %; is the carbon emission intensity of the sewage treatment plant in the base year, kg CO2e / m 3 ; is the average value of the carbon emission intensity of the national sewage treatment plants, kg CO2e / m 3 ; is the optimal value of the carbon emission intensity of the national sewage treatment plants, kg CO2e / m 3 .

[0020] According to a particularly preferred specific embodiment, in step (1), setting the preliminary scientific carbon target includes: When x≥0: The carbon emission level is poor, and it is not appropriate to set extreme indicators. Achieve carbon neutrality as planned; The short- and medium-term target is set to decrease by 0-25% compared with the base year; When x<0, y≥50%: The carbon emission level is average, and a stepped carbon reduction target should be set. Achieve carbon neutrality as planned; The short- and medium-term target is set to decrease by 25%-50% compared with the base year; When x<0, 0<y<50%: The carbon emission level is good, raise the carbon reduction target, and achieve carbon neutrality in advance; The short- and medium-term target is set to decrease by 50%-75% compared with the base year; When y≤0: The carbon emission level is excellent, establish a leading carbon emission reduction benchmark in the industry, and accelerate the achievement of carbon neutrality; The short- and medium-term target is set to decrease by 75%-100% compared with the base year.

[0021] In the present invention, through literature analysis combined with on-site research, a low-carbon technology list for sewage treatment plants is constructed from five aspects: equipment energy conservation, process improvement, intelligent control, energy recovery and resource recycling; and the low-carbon technologies are quantitatively analyzed from the aspects of carbon reduction benefits, economic benefits and technical maturity.

[0022] According to a particularly preferred specific embodiment, in step (3), the analysis methods combining carbon reduction benefits, economic benefits and technical maturity include: Analysis of carbon reduction benefits:

[0023] Carbon emission reduction of a single low-carbon technology: ; Wherein, : Carbon emission reduction of technology i in year t, t CO2e; : Direct carbon emissions of the sewage treatment plant in the base year, t CO2e; : Degree of direct carbon emission reduction of technology i, %; : Power consumption of type j of the sewage treatment plant in the base year, kWh; : Power emission factor in year t, kg CO2e / kWh; : Degree of power consumption reduction of type j of technology i, %; : Power generation or substitution power of technology i in year t, kWh; : Chemical agent k Carbon emissions in the base year, t CO2e; : Reduction amount of type k chemical agent of technology i, %; n : Types of chemical agents consumed by the sewage treatment plant; : Carbon emissions of the treated wastewater of the sewage treatment plant in the base year, tCO2e; : Degree of carbon emission reduction of the treated wastewater of technology i, %; : Carbon sink volume of technology i in year t, t CO2e;

[0024] When process improvement technologies and intelligent control low-carbon technologies are implemented simultaneously, there is a synergistic effect, and the carbon emission reduction cannot be obtained by addition. The carbon emission reduction of combined low-carbon technologies needs to be calculated according to the following method: ; Wherein, : Carbon emission reduction of process improvement technology I combined with intelligent control technology i in year t, t CO2e; : Direct carbon emissions of the sewage treatment plant in the base year, t CO2e; : Degree of direct carbon emission reduction of process improvement technology I, %; : Degree of direct carbon emission reduction of intelligent control technology i, %; : Of the sewage treatment plant in the base year J Type of power consumption, kWh; : Of the sewage treatment plant in the base year j Type of power consumption, kWh; : Power emission factor in year t, kg CO2e / kWh; : Process improvement technology I Of JDegree of reduction in power consumption of the type, %; : Intelligent control technology i of j Degree of reduction in power consumption of the type, %; : Chemical agent K Carbon emissions in the base year, t CO2e; : Chemical agent k Carbon emissions in the base year, t CO2e; : Process improvement technology I of K Reduction amount of the type of chemical agent, %; :: Intelligent control technology i of k Reduction amount of the type of chemical agent, %; n : Types of chemical agents consumed by the sewage treatment plant; : Tail water carbon emissions of the sewage treatment plant in the base year, t CO2e; : Process improvement technology I Degree of reduction in tail water carbon emissions, %; Among them, only 1 item of process improvement technology can be selected.

[0025] According to a preferred specific implementation manner, the economic benefit analysis includes:

[0026] Use the marginal abatement cost curve method to evaluate the low-carbon technology measures of the sewage treatment plant and assign the economic indicator Y i (yuan / tCO2e), and the calculation formula is:

[0027] The total cost includes the initial construction cost and the net operating cost in the next 10 years (that is, the difference between the operating cost and the revenue), and its calculation formula is as follows: ; The carbon abatement potential of each carbon reduction measure is based on the average annual emission reduction amount within 10 years after the implementation of the measure multiplied by the time period (10 years), and the total carbon abatement potential formula is: ; The marginal abatement cost is calculated through the following formula: .

[0028] According to a preferred specific implementation manner, the technology maturity analysis includes:

[0029] The technology readiness level (TRL) is a key indicator to measure the practical degree of technology industrialization. The NASA-proposed 9-level evaluation system is used to classify the low-carbon technologies of the sewage treatment plant, and it is evaluated step by step from the discovery of basic principles (TRL1) to the verification of actual system application (TRL9), providing a scientific basis for the feasibility screening of carbon reduction technologies (the higher the level, the more mature);

[0030] Among them, the technology readiness level is defined as follows:

[0031] Level 1: The basic principle is discovered or reported;

[0032] Level 2: The technical concept or application is clarified;

[0033] Level 3: Proof of concept for key functions or characteristics;

[0034] Level 4: Verification of components or test models in a laboratory environment;

[0035] Level 5: Verification of components or test models in a relevant environment;

[0036] Level 6: Verification of system / subsystem models or prototypes in a relevant environment;

[0037] Level 7: Verification of system prototypes in a simulated usage environment;

[0038] Level 8: Completion of test verification of the actual system;

[0039] Level 9: Completion of usage verification of the actual system;

[0040] Preferably, in step (3), calculate the application time of various low-carbon technologies according to the following formula, assign a time limit to reflect the dynamics: , where " " is in the unit of "year"; "TRL" is the technology readiness level.

[0041] Preferably, in step (4), the construction of the low-carbon development path planning model includes: ; In the formula, : The carbon emissions of the sewage treatment plant in year t, t CO2e; : The total carbon reduction of the low-carbon technologies adopted by the sewage treatment plant in year t, t CO2e.

[0042] Further preferably, in step (4), input the initially set scientific carbon target into the low-carbon development path planning model, verify its rationality, and adjust it to the final scientific carbon target, and at the same time generate a low-carbon development path, where the verification and determination of the scientific carbon target are as follows: According to the initially set preliminary scientific carbon target and give a 5% error range, construct a target constraint function: ;

[0043] Where m% is the preliminary science-based carbon target; "m%~(m + 5)%" is a 5% error range given based on the initially set preliminary science-based carbon target; is the carbon emission of the sewage treatment plant in year t, in t CO2e; is the total carbon reduction of the low-carbon technologies adopted by the sewage treatment plant in year t, in t CO2e; is the carbon emission of the sewage treatment plant in the baseline year, in t CO2e;

[0044] If this inequality has a solution, then set the science-based carbon target of the sewage treatment plant in year t as m%;

[0045] If this inequality has no solution, then adjust the preliminary science-based carbon target, set the reduction amount as a%, until this inequality has a solution, and then set the science-based carbon target of the sewage treatment plant in year t as m% - a%;

[0046] In the case where the inequality has a solution, moderately increase the preliminary science-based carbon target, set the increase amount as b%, then set the science-based carbon target of the sewage treatment plant in year t as m% + b%.

[0047] Preferably, in step (4), the determination of the low-carbon development path is as follows:

[0048] If after determining the science-based carbon target, the above inequality has one and only one solution set, then this path is the low-carbon development path of the sewage treatment plant;

[0049] If after determining the science-based carbon target, the above inequality has multiple solution sets, then find the economically optimal solution according to the following function and set it as the low-carbon development path of the sewage treatment plant; ; Where : The total carbon reduction of the low-carbon technologies in each solution set, in t CO2e; : The marginal cost of each low-carbon technology, in yuan / tCO2e.

[0050] According to a particularly preferred specific implementation manner, a method for constructing the science-based carbon target and low-carbon development path of a sewage treatment plant, the method includes the following steps: (1) Calculate the carbon emission intensity of the sewage treatment plant in the baseline year, and compare it with the average value and the optimal value of the national sewage treatment plants to determine the relative level of the sewage treatment plant in the industry, and thus set the preliminary science-based carbon target based on the top-down method; (2) Through literature analysis and on-site research, construct a list of low-carbon technology measures for the A 2 O + MBR treatment process from aspects of equipment energy conservation, process improvement, intelligent control, energy recovery, and resource recycling; (3) Based on the actual operation data of the sewage treatment plant in the base year, combined with the environmental benefits, economic benefits, and technology maturity analysis methods, quantify the low-carbon technology measure list of the AO+MBR treatment process to obtain the quantification results of the low-carbon technology measure list for the 8 years after the base year; 2 (4) Based on the actual operation data of the sewage treatment plant in the base year, combined with the environmental benefits, economic benefits, and technology maturity analysis methods, quantify the low-carbon technology measure list of the AO+MBR treatment process to obtain the quantification results of the low-carbon technology measure list for the 28 years after the base year; (4) Based on the actual operation data of the sewage treatment plant in the base year, combined with the environmental benefits, economic benefits, and technology maturity analysis methods, quantify the low-carbon technology measure list of the AO+MBR treatment process to obtain the quantification results of the low-carbon technology measure list for the 28 years after the base year; 2 (6) Based on the actual operation data of the sewage treatment plant in the base year, only considering the change of the electricity factor, calculate the total carbon emissions of the sewage treatment plant for the 28 years after the base year; (5) Based on the actual operation data of the sewage treatment plant in the base year, only considering the change of the electricity factor, calculate the total carbon emissions of the sewage treatment plant for the 28 years after the base year; Then, reduce the carbon emission intensity of the "preliminary scientific carbon target for 8 years after the base year" by 50% compared with the base year and input it into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target for 8 years after the base year"; (6) Based on the actual operation data of the sewage treatment plant in the base year, only considering the change of the electricity factor, calculate the total carbon emissions of the sewage treatment plant for the 8 years after the base year; Then, reduce the carbon emission intensity of the "preliminary scientific carbon target for 28 years after the base year" by 100% compared with the base year and input it into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target for 28 years after the base year".

[0051] The present invention will be described in detail below through embodiments.

[0052] In the following examples, without special instructions, in steps (3) and (4), due to the change of the electricity factor, the carbon reduction amount of low-carbon technologies varies from year to year; secondly, due to different technology maturities, the low-carbon technologies that can be adopted each year are also different; therefore, it reflects the dynamics of the low-carbon technology quantification method; specifically, on the one hand, the carbon reduction amount of the same low-carbon technology in 2030 and 2050 is different, mainly due to the change of the electricity factor, and on the other hand, according to the technology maturity evaluation results, the low-carbon technologies that can be adopted in 2050 are significantly more than those in 2030.

[0053] Embodiment This example is used to combine Figure 1 Provide a method for constructing a scientific carbon target and a low-carbon development path for a sewage treatment plant, the method includes: (1) Calculate the carbon emission intensity of sewage treatment plant F in 2022 and compare it with the average value and the optimal value of national sewage treatment plants to determine the relative level of the sewage treatment plant F in the industry, and thus set a preliminary scientific carbon target based on the top-down method; In this embodiment, the designed treatment scale of the sewage treatment plant F is 90,000 tons per day;

[0054] Calculate the total carbon emissions according to the following formula: , which is 9708.50 tCO2e in this embodiment;

[0055] Calculate the carbon emission intensity according to the following formula: , which is 0.324 kg CO2e / m 3 ;

[0056] Adopt the A 2 O+MBR treatment process, and the effluent meets the first-class A standard in the "Discharge Standard of Pollutants for Municipal Wastewater Treatment Plants" (GB18918-2002); in 2022, the average carbon emission intensity of the A 2 O+MBR treatment process in national sewage treatment plants is 0.709 kg CO2e / m 3 , and the optimal value is 0.202 kg CO2e / m 3 ;

[0057] Calculate x and y according to the following formula: ; ;

[0058] In this embodiment, x is -119% (<0) and y is 40% (<50%); then the "preliminary scientific carbon target" can be set as a 50% reduction in carbon emission intensity in 2030 compared with 2022, and a 100% reduction in 2050, that is, carbon neutrality is achieved.

[0059] (2) Through literature analysis and field research, construct a list of low-carbon technology measures for the A 2 O+MBR treatment process from aspects of equipment energy conservation, process improvement, intelligent control, energy recovery, and resource recycling. In this embodiment, it is shown in Table 1.

[0060] Table 1

[0061] (3) Based on the actual operation data of the sewage treatment plant F in 2022, combined with the carbon reduction benefit, economic benefit, and technology maturity analysis methods, quantify the list of low-carbon technology measures for the A 2 O+MBR treatment process, and obtain the quantification results of the list of low-carbon technology measures in 2030 shown in Table 2, and obtain the quantification results of the technology combination of process improvement and intelligent control in 2030 shown in Table 3.

[0062] Table 2

[0063] Table 3

[0064] (4) Based on the actual operation data of sewage treatment plant F in 2022, combined with environmental, economic, and technological maturity analysis methods, quantify the low-carbon technology measure list of the AO+MBR treatment process, obtain the quantified results of the low-carbon technology measure list in 2050 shown in Table 4, and obtain the quantified results of the process improvement and intelligent control technology combination in 2050 shown in Table 5. 2

[0065] Table 4

[0066] Table 5

[0067] (5) Based on the actual operation data of sewage treatment plant F in 2022, only considering the change of the electricity factor, calculate the total carbon emissions of sewage treatment plant F in 2030 (about 8480.58 tCO2e); Then input the set "preliminary scientific carbon target in 2030" with a 50% reduction in carbon emission intensity compared to 2022 into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target in 2030"; since the treatment volume of the sewage treatment plant remains unchanged, the inequality is: ; One of the solution sets is {update of the blower pipeline, replacement of traditional diffusers with ultra-fine bubble diffusers, intelligent aeration, intelligent addition of carbon source, intelligent addition of phosphorus removal agents, photovoltaic power generation, water source heat pump, 25% reuse of reclaimed water, aerobic composting of sludge + land use}, indicating that this inequality has a solution and the preliminary scientific carbon target is reasonably set.

[0068] In summary, the scientific carbon target of sewage treatment plant F in 2030 can be set to a 50% reduction in carbon emission intensity compared to 2022; the low-carbon path to achieve this goal is: update of the blower pipeline, replacement of traditional diffusers with ultra-fine bubble diffusers, intelligent aeration, intelligent addition of carbon source, intelligent addition of phosphorus removal agents, photovoltaic power generation, water source heat pump, 25% reuse of reclaimed water, and aerobic composting of sludge + land use.

[0069] (6) Based on the actual operation data of sewage treatment plant F in 2022, only considering the change of the electricity factor, calculate the total carbon emissions of sewage treatment plant F in 2050 (about 5893.43 tCO2e in this embodiment); Then input the set "preliminary scientific carbon target in 2050" with a 100% reduction in carbon emission intensity compared to 2022 into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target in 2050"; since the treatment volume of the sewage treatment plant remains unchanged, the inequality is: ; One of the solution sets is {blast pipe update, ultra-fine bubble diffuser replacing traditional diffuser, anaerobic ammonium oxidation process, intelligent aeration, intelligent carbon source dosing, intelligent phosphorus removal agent dosing, intelligent management and control platform, photovoltaic power generation, water source heat pump, 50% reclaimed water reuse, recovery of phosphorus by struvite fluidized bed reactor, sludge anaerobic digestion + cogeneration + dewatering + land use}, indicating that this inequality has a solution and the preliminary scientific carbon target is set reasonably.

[0070] In summary, the scientific carbon target of wastewater treatment plant F in 2050 can be set to a 100% reduction in carbon emission intensity compared to 2022, that is, to achieve carbon neutrality; the low-carbon path to achieve this goal is: blast pipe update, ultra-fine bubble diffuser replacing traditional diffuser, anaerobic ammonium oxidation process, intelligent aeration, intelligent carbon source dosing, intelligent phosphorus removal agent dosing, intelligent management and control platform, photovoltaic power generation, water source heat pump, 50% reclaimed water reuse, recovery of phosphorus by struvite fluidized bed reactor, and sludge anaerobic digestion + cogeneration + dewatering + land use.

[0071] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited thereto. Within the technical concept of the present invention, various simple modifications can be made to the technical solutions of the present invention, including any other suitable combination of each technical feature. These simple modifications and combinations should also be regarded as the content disclosed by the present invention and fall within the protection scope of the present invention.

Claims

1. A method for constructing a scientific carbon target and a low-carbon development path for a sewage treatment plant, characterized in that The method includes the following steps: (1) Calculate the carbon emission intensity of the sewage treatment plant in the base year, and compare it with the average value and the optimal value of the national sewage treatment plants to determine the relative level of the sewage treatment plant in the industry, and thus set a preliminary scientific carbon target based on the top-down method; (2) Through literature analysis and on-site research, construct a list of low-carbon technology measures for the sewage treatment plant from aspects such as equipment energy conservation, process improvement, intelligent control, energy recovery, and resource recycling; (3) Based on the actual operation data of the sewage treatment plant in the base year, combined with the carbon reduction benefit, economic benefit, and technology maturity analysis methods, quantify the list of low-carbon technology measures for the sewage treatment plant to obtain the quantification result of the list of low-carbon technology measures in the target year; (4) Based on the actual operation data of the sewage treatment plant in the base year, only considering the change of the electricity factor, calculate the carbon emission of the sewage treatment plant in the target year; then input the set "preliminary scientific carbon target" into the low-carbon development path planning model to verify the "rationality of the preliminary scientific carbon target", and adjust it to the final scientific carbon target, and at the same time generate a low-carbon development path.

2. The method according to claim 1, wherein In step (1), comparing the carbon emission intensity of the sewage treatment plant in the base year with the average value and the optimal value of the national sewage treatment plants to determine the relative level of the sewage treatment plant in the industry, and thus setting a preliminary scientific carbon target based on the top-down method, includes: ； ； Where x is the difference from the average value, %; y is the difference from the optimal value, %. is the carbon emission intensity of the sewage treatment plant in the base year, kg CO2e / m 3 ; is the average value of the carbon emission intensity of national sewage treatment plants, kg CO2e / m 3 ; is the optimal value of the carbon emission intensity of national sewage treatment plants, kg CO2e / m 3 .

3. The method according to claim 2, wherein In step (1), setting the preliminary scientific carbon target includes: When x≥0: The carbon emission level is poor, it is not appropriate to set extreme indicators, and achieve carbon neutrality as planned; the short- and medium-term target is set to decrease by 0-25% compared with the base year; When x<0 and y≥50%: The carbon emission level is average, a stepped carbon reduction target should be set, and achieve carbon neutrality as planned; the short- and medium-term target is set to decrease by 25%-50% compared with the base year; When x<0 and 0<y<50%: The carbon emission level is good, raise the carbon reduction target and achieve carbon neutrality in advance; the short- and medium-term target is set to decrease by 50%-75% compared with the base year; When y≤0: The carbon emission level is excellent, set a leading carbon emission reduction benchmark in the industry and accelerate the achievement of carbon neutrality; the short- and medium-term target is set to decrease by 75%-100% compared with the base year.

4. The method according to claim 1 or 2, characterized in that, In step (3), the combination of the carbon reduction benefit, economic benefit, and technology maturity analysis methods includes: Carbon reduction benefit analysis: Carbon reduction amount of a single low-carbon technology: ； Wherein, : The carbon emission reduction of technology i in year t, t CO2e; : The direct carbon emissions of the sewage treatment plant in the base year, tCO2e; : The direct carbon emission reduction degree of technology i, %; : The power consumption of type j of the sewage treatment plant in the base year, kWh; : The electricity emission factor in year t, kg CO2e / kWh; : Technology i 's j The degree of reduction in power consumption of type, %; : Technology i In t The electricity generation or substitution amount in year, kWh; : Chemical agent k The carbon emissions in the base year, t CO2e; : Technology i 's k The reduction amount of this type of chemical agent, %; n : The types of chemical agents consumed by the sewage treatment plant; : The carbon emissions of the treated effluent of the sewage treatment plant in the base year, tCO2e; : Technology i The reduction degree of carbon emissions of the treated effluent, %; : Technology i In t The carbon sink amount in year, t CO2e; Since there is a synergistic effect when the process improvement technology and the intelligent control low-carbon technology are implemented simultaneously, the carbon reduction amount cannot be obtained by addition, and the carbon reduction amount of the combined low-carbon technology needs to be calculated according to the following method: ； wherein : Process improvement technology I Combined intelligent control technology i The carbon emission reduction in t year, t CO2e; : Direct carbon emissions of the sewage treatment plant in the base year, t CO2e; : Process improvement technology I Degree of direct carbon emission reduction, %; : Intelligent control technology i Degree of direct carbon emission reduction, %; : The J Type of power consumption of the sewage treatment plant in the base year, kWh; : The j Type of power consumption of the sewage treatment plant in the base year, kWh; : t Power emission factor in : Process improvement technology I The J Degree of reduction in type of power consumption, %; : Intelligent control technology i The j Degree of reduction in type of power consumption, %; Reagent K Carbon emissions in the base year, t CO2e; : Reagent k Carbon emissions in the base year, t CO2e; : The K Degree of reduction in type of reagent of process improvement technology I, %; : Intelligent control technology i The k Degree of reduction in type of reagent, %; n : Types of reagents consumed by the sewage treatment plant; : Tail water carbon emissions of the sewage treatment plant in the base year, t CO2e; : Process improvement technology I Degree of tail water carbon emission reduction, %; Among them, only 1 item of process improvement technology can be selected.

5. The method according to claim 1 or 2, characterized in that In step (3), calculate the application time of various low-carbon technologies according to the following formula, and give a time limit to reflect the dynamics: , where the unit of " " is "year"; "TRL" is the technology readiness level.

6. The method according to claim 1 or 2, characterized in that, In step (4), the construction of the low-carbon development path planning model includes: ； Wherein, : The carbon emissions of the sewage treatment plant in year t, t CO2e; : The total carbon reduction of the low-carbon technologies adopted by the sewage treatment plant in year t, t CO2e.

7. The method according to claim 1 or 2, characterized in that, In step (4), input the preliminarily set scientific carbon target into the low-carbon development path planning model, verify its rationality, and adjust it to the final scientific carbon target, and at the same time generate a low-carbon development path, where the verification and determination of the scientific carbon target are as follows: According to the initially set preliminary scientific carbon target, and giving a 5% error range, construct a target constraint function: ； Where m% is the preliminary science-based carbon target; "m%~(m + 5)%" is the 5% error range given according to the initially set preliminary science-based carbon target; is the carbon emission of the sewage treatment plant in year t, t CO2e; is the total carbon reduction of the low-carbon technologies adopted by the sewage treatment plant in year t, t CO2e; is the carbon emission of the sewage treatment plant in the base year, t CO2e; If this inequality has a solution, set the scientific carbon target for the sewage treatment plant in year t as m%; If this inequality has no solution, adjust the preliminary scientific carbon target, set the reduction amount as a%, until this inequality has a solution, then set the scientific carbon target for the sewage treatment plant in year t as m% - a%; When the inequality has a solution, moderately increase the preliminary scientific carbon target, set the increase amount as b%, then set the scientific carbon target for the sewage treatment plant in year t as m% + b%.

8. The method according to claim 7, wherein In step (4), the low-carbon development path is determined as follows: If after determining the scientific carbon target, the above inequality has one and only one solution set, then this path is the low-carbon development path of the sewage treatment plant; If after determining the scientific carbon target, the above inequality has multiple solution sets, then find the economically optimal solution according to the following function and set it as the low-carbon development path of the sewage treatment plant; ； In the formula, : The total carbon reduction of low-carbon technologies in each solution set, t CO2e; : The marginal cost of each low-carbon technology, yuan / tCO2e.

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