A quantitative method and system for the contribution of river nitrous oxide sources and fate processes.

Abstract

This invention discloses a quantitative method and system for the contribution of river nitrous oxide sources and fate processes, relating to the field of biotechnology. The method includes: collecting surface water and groundwater samples; determining the physicochemical properties of the water samples, including calculating and quantifying the water-to-groundwater exchange ratio; extracting dissolved nitrous oxide from the water samples after determining the physicochemical properties and performing isotope analysis on the nitrous oxide to generate isotope test results; conducting indoor culture experiments on the water samples after completing the isotope analysis to determine whether there are abiotic sources of nitrous oxide in the water samples, generating indoor culture results; and quantifying the contribution of river nitrous oxide sources based on the results of the water-to-groundwater exchange ratio, the isotope test results, and the indoor culture results. This invention effectively analyzes the sources and fate processes of nitrous oxide in rivers and accurately quantifies the contributions of different sources.

Description

Technical Field

[0001] This invention belongs to the field of biotechnology, specifically relating to a quantitative method and system for the contribution of river nitrous oxide sources and fate processes. Background Technology

[0002] Nitrous oxide, a potent greenhouse gas, has a global warming potential approximately 300 times that of carbon dioxide on a centennial timescale, posing a serious threat to ozone layer depletion. The Sixth Assessment Report of the Intergovernmental Panel on Climate Change (IPC) found a significant increase in global atmospheric nitrous oxide concentrations, primarily originating from agricultural soils and aquatic ecosystems. Human activities (fertilizer application, manure return to fields, and sewage discharge) result in substantial nitrogen input into rivers, making rivers a significant source of nitrous oxide emissions. Studying riverine nitrous oxide release is of significant scientific importance for clarifying nitrogen migration and transformation processes in rivers and determining their contribution to atmospheric nitrous oxide.

[0003] Accurate quantification of the source (generation and input) and sink (release and output) fluxes of nitrous oxide in river systems is a prerequisite for developing process-based nitrogen management strategies. Currently, most studies consider nitrous oxide in water bodies to originate from microbial processes, primarily including nitrification, bacterial and fungal denitrification, nitrifying bacterial denitrification, and dissimilatory reduction of nitrate to ammonium (DNRA). However, with advancements in detection technologies, increasing research has revealed the role of abiotic processes in nitrous oxide production. Specifically, during nitrate reduction, hydroxylamine and nitrite, coupled with iron / manganese oxides and humic substances, can generate nitrous oxide, suggesting that the contribution of abiotic processes to nitrous oxide production may be underestimated. Furthermore, existing techniques neglect the impact of external sources (surface runoff and groundwater input) and sink (release and output) processes on river nitrous oxide production. A recent study on global river nitrous oxide emissions based on a terrestrial ecosystem model coupled with hydrology and biogeochemistry shows that groundwater contributes more than 80% of nitrous oxide emissions. Therefore, considering only microbially mediated endogenous nitrous oxide release while ignoring abiotic processes and the contributions of exogenous nitrous oxide from groundwater and upstream sources will introduce significant uncertainty into the estimation of river nitrous oxide emissions.

[0004] Therefore, there is an urgent need to provide a solution to improve the above problems. Summary of the Invention

[0005] The purpose of this invention is to provide a quantitative method and system for the contribution of river nitrous oxide sources and fate processes, which can solve the problems of existing technologies that make it difficult to determine the sources and fate processes of nitrous oxide in rivers, and that cannot accurately quantify the contributions of different sources.

[0006] To solve the above-mentioned technical problems, the present invention is implemented as follows:

[0007] In a first aspect, embodiments of the present invention provide a quantitative method for the contribution of river nitrous oxide sources and fate processes, the method comprising:

[0008] Collect surface water and groundwater to obtain water samples;

[0009] The physicochemical indicators of water samples are determined, including: calculating and quantifying the exchange ratio between river water and groundwater.

[0010] After determining the physicochemical indicators, dissolved nitrous oxide was extracted from the water sample, and isotope testing was performed on the nitrous oxide to generate isotope test results.

[0011] After completing the isotope testing, an indoor culture experiment was conducted on the water samples to determine whether there were any sources of nitrous oxide from abiotic processes in the water samples, and the results of the indoor culture were generated.

[0012] Based on the results of the exchange ratio between river water and groundwater, isotope testing results, and indoor culture results, the contribution of river nitrous oxide sources was quantitatively determined.

[0013] Optionally, the specific steps for obtaining water samples include:

[0014] Surface water and groundwater were collected along the river in different seasons, including the high-water season, normal-water season, and low-water season. Flow velocity and flow rate were measured on-site using a Doppler flow meter. Water depth was estimated by averaging the values ​​of three points evenly distributed along the river's cross-section using a ruler. Water temperature was measured on-site using a portable multi-parameter water quality monitor. Water samples were stored at 4°C and quickly transported back to the laboratory.

[0015] Optionally, during isotope testing, additional steps were taken. 222 The Rn activity test, among which, 222 The testing of Rn activity specifically includes:

[0016] A 100ml water sample was placed in a brown glass bottle and tested on-site using a radon meter. 222 Rn activity;

[0017] The process of isotope testing specifically includes:

[0018] Dissolved nitrous oxide was collected on-site using a headspace method, and its isotopes were analyzed. δ 15 N α and δ 18 O was determined using isotope ratio mass spectrometry. and The value is calculated using the following formula:

[0019] ;

[0020] ;

[0021] Among them, the N isotope of nitrous oxide It can appear in the middle position and the end position, respectively called... and , Intermolecular forces of nitrous oxide 15 N-site preference;

[0022] Stable isotope ratios are expressed as follows:

[0023] ;

[0024] in, Indicates the stable isotope ratio. and They are respectively 15 N / 14 N or 18 O / 16 O's samples and standards;

[0025] The process of calculating the quantitative exchange ratio between river water and groundwater includes: calculating the exchange flux between river water and groundwater, calculating groundwater recharge to river water, calculating river water recharge to groundwater, and calculating the bidirectional conversion ratio between river water and groundwater.

[0026] The specific steps for calculating the exchange flux between river water and groundwater include:

[0027] The natural decay coefficient of radon isotopes suspended in riverbed sediments and river water was calculated based on the molecular diffusion coefficient. The mathematical expression for the natural decay coefficient is as follows:

[0028] ;

[0029] in, express 222 The natural decay coefficient of Rn, Indicates the river flow velocity. Indicates the depth of the river. This represents the radiative decay coefficient. express 222 The molecular diffusion coefficient of Rn is related to the temperature of the water. The relevant mathematical expression is:

[0030] ;

[0031] The specific steps for calculating groundwater recharge into the river include:

[0032] ;

[0033] in, The upstream and downstream river waters are respectively 222 The concentration of Rn, These are the upstream and downstream river flows, respectively. This is the distance between the upstream and downstream sections. groundwater 222 The concentration of Rn, This represents the groundwater recharge rate within this river section.

[0034] The specific steps for calculating the recharge of groundwater by river water include:

[0035] ;

[0036] in, The rate of river water seepage;

[0037] The specific steps for calculating the bidirectional conversion between river water and groundwater include:

[0038] ;

[0039] ;

[0040] The specific steps for calculating the supply ratio include:

[0041] ;

[0042] in, This indicates the relative proportion of groundwater replenishing river water. This indicates the percentage of river water leakage.

[0043] Optional, the specific steps for conducting indoor culture experiments on water samples include:

[0044] Insert a copper tube into the bottom of the serum bottle, inject water sample until it overflows several times its volume, and seal it with an airtight butyl rubber stopper.

[0045] The serum bottles were pre-incubated in an incubator for several days until the nitrate NO3 level was reached. - and nitrite NO2 - Continue until it is undetectable;

[0046] After the pre-incubation, the bottles were rinsed again with helium, and the water samples were divided into two groups: one group was sterilized by filtration and used for the non-biological nitrous oxide generation experiment, and the other group was used for the biological nitrous oxide generation experiment. Subsequently, the water samples were placed into serum bottles, rinsed with helium, and sealed with airtight butyl rubber stoppers. Three types of nitrogen treatments were added to each group of bottles: a control group without nitrogen, a group with added KNO3, and a group with added KNO2. The concentration of added nitrogen depended on the nitrogen concentration of the water in the mining area. All bottles were incubated in the dark and at temperatures as close as possible to the in-situ conditions. At five time points, 10 mL of gas was replaced with helium at 0 h, 12 h, 24 h, 36 h, and 48 h to determine the nitrous oxide concentration and isotope index.

[0047] Optionally, the process of quantifying the contribution of river nitrous oxide sources includes: classifying the sources of river nitrous oxide and quantifying the contribution of endogenous nitrous oxide processes. The process of classifying the sources of river nitrous oxide includes: classifying river nitrous oxide into exogenous replenishment and endogenous generation.

[0048] Optional, specific procedures for quantifying the contribution of endogenous nitrous oxide oxidation include:

[0049] The reactions in the nitrous oxide production process are divided into microbial and abiotic sources to obtain the contributions of different processes. The contributions of these different processes are quantified to obtain the equilibrium equation, the mathematical expression of which is:

[0050] ;

[0051] in, , , , , It represents the proportion of reaction pathways that produce nitrous oxide. , , , , These are the isotopic characteristic values ​​of the reaction pathway. r It is the residual of the proportion of unreduced nitrous oxide. A It is the isotopic fractionation coefficient of nitrous oxide reduction. μ The isotopic value representing the final nitrous oxide.

[0052] Optionally, exogenous supply and endogenous generation are calculated using an isotope endmember mixing model, with the mathematical expression as follows:

[0053] ;

[0054] ;

[0055] in, , , , These are the characteristic values ​​of nitrous oxide isotopes from river dissolution, groundwater recharge, endogenous sources, and upstream river transport, respectively. , , All of these can be obtained through water sample collection and testing; the removal rate of nitrous oxide transport in groundwater and upstream rivers is not considered at this time. , and The figures represent the proportions of groundwater recharge and endogenous generation, and upstream river carryover, respectively, contributing to dissolved nitrous oxide at river sampling points. pass 222 The groundwater recharge ratio is obtained by calculating Rn.

[0056] Secondly, embodiments of the present invention provide a quantitative system for the contribution of river nitrous oxide sources and fate processes, the system comprising:

[0057] The data collection module is used to collect surface water and groundwater to obtain water samples.

[0058] The physicochemical index determination module is used to determine the physicochemical indexes of water samples. The physicochemical index determination includes: calculating and quantifying the exchange ratio between river water and groundwater.

[0059] The isotope testing module is used to extract dissolved nitrous oxide from water samples after the physicochemical indicators have been determined, and to perform isotope testing on the nitrous oxide to generate isotope test results.

[0060] The indoor culture module is used to conduct indoor culture experiments on water samples after isotope testing to determine whether there are non-biological sources of nitrous oxide in the water samples and to generate indoor culture results.

[0061] The quantitative module is used to quantify the contribution of river nitrous oxide sources based on the results of the exchange ratio between river water and groundwater, isotope testing results, and indoor culture results.

[0062] Thirdly, embodiments of this application provide an electronic device including a processor, a memory, and a program or instructions stored in the memory and executable on the processor, wherein the program or instructions, when executed by the processor, implement the steps of the method as described in the first aspect.

[0063] Fourthly, embodiments of this application provide a readable storage medium on which a program or instructions are stored, and when the program or instructions are executed by a processor, they implement the steps of the method as described in the first aspect.

[0064] Compared with existing technologies, the beneficial effects of the quantitative method for the contribution of nitrous oxide sources and fate processes in rivers proposed in this invention are as follows: This invention effectively analyzes the sources and fate processes of nitrous oxide in rivers and accurately quantifies the contributions of different sources, providing a high-precision accounting method for the global greenhouse gas inventory, supporting the assessment of emission reduction targets, providing a scientific basis for the coordinated management and ecological restoration of nitrogen pollution in polluted rivers, and promoting the precision of watershed management and global climate action. Attached Figure Description

[0065] Figure 1 A flowchart illustrating a quantitative method for the contribution of river nitrous oxide sources and fate processes provided in the first embodiment of the present invention;

[0066] Figure 2 This diagram illustrates the overall architecture of a quantitative method for the contribution of river nitrous oxide sources and fate processes, as provided in the first embodiment of the present invention.

[0067] Figure 3 This diagram illustrates the sources and fate pathways of nitrous oxide in rivers, as provided in the first embodiment of the present invention.

[0068] Figure 4 A diagram illustrating the processing and result indication of the indoor culture experiment provided in the first embodiment of the present invention;

[0069] Figure 5 This is an internal structural diagram illustrating the contribution of a quantitative system to the source and fate of nitrous oxide in rivers, as provided in the second embodiment of the present invention. Detailed Implementation

[0070] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0071] The terms "first," "second," etc., used in the specification and claims of this invention are used to distinguish similar objects and are not used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention can be implemented in orders other than those illustrated or described herein. Furthermore, in the specification and claims, "and / or" indicates at least one of the connected objects, and the character " / " generally indicates that the preceding and following objects are in an "or" relationship.

[0072] The following detailed description, in conjunction with the accompanying drawings, of a quantitative method and system for assessing the contribution of river nitrous oxide sources and fate processes provided by the present invention through specific embodiments and application scenarios, illustrates in detail the following:

[0073] Example 1

[0074] Please see Figure 1 The diagram shows the overall flow chart of a quantitative method for the contribution of river nitrous oxide sources and fate processes provided by the present invention, which includes steps S1 to S5.

[0075] S1: Collect surface water and groundwater to obtain water samples.

[0076] Specifically, to compare the differences in water exchange across different seasons, surface water was collected along the river during different seasons (high-water season, normal-water season, and low-water season). Groundwater was collected from wells within a 1-2 km radius on both sides of the riverbank. Flow velocity and flow rate were measured on-site using a Doppler flowmeter; water depth was estimated by averaging the values ​​of three points evenly distributed along the river's cross-section using a ruler. Water temperature was measured on-site using a portable multi-parameter water quality monitor. Water samples were used for isotope analysis (filtered through a 0.45 μm membrane) and were stored at 4°C for rapid transport back to the laboratory for preservation.

[0077] S2: Determine the physicochemical properties of water samples. The determination of physicochemical properties includes:

[0078] S2-1. In this invention, 100 mL of water sample is placed in a brown glass bottle, and radon is measured on-site using a radon analyzer. 222 Rn activity;

[0079] S2-2, Calculate and quantify the exchange ratio between river water and groundwater.

[0080] Specifically, in performing step S2-2, the present invention quantifies the exchange ratio between river water and groundwater, including: calculating the exchange flux between river water and groundwater, calculating the groundwater replenishment of river water, calculating the river water replenishment of groundwater, and calculating the replenishment ratio of the bidirectional conversion between river water and groundwater.

[0081] The process of calculating the exchange flux between river water and groundwater includes: riverbed sediments and suspended particles in river water. 222 Rn release is very small, as determined by field measurements of river water and groundwater. 222 Using Rn concentration and cross-sectional flow rate, the exchange flux between the two waters can be effectively calculated using the mass balance equation. River water... 222 The equilibrium equation for Rn between river cross sections is used in this study, neglecting river water evaporation and suspended particle release. 222 Rn, the formula is as follows:

[0082] ;

[0083] In the formula, for 222 The natural decay coefficient of Rn ( / s), D for 222 Molecular diffusion coefficient of Rn (cm) 2 ·s -1 ); v The velocity of the river water is (m / s); h λ represents the river depth (m); λ is the radiation decay constant (2.08 × 10⁻⁶). -6 / s). Parameters D With the temperature of water T (°C) is related to the calculation formula:

[0084] ;

[0085] Furthermore, the calculation of the process by which groundwater recharges river water includes:

[0086] ;

[0087] in, C u , C d The upstream and downstream river waters are respectively 222 Rn concentration (Bq / m³) 3 ); Q u , Q d The upstream and downstream river flows (m³) are respectively 3 / s); L The distance between the upstream and downstream sections is in meters (m). C g groundwater 222 Rn concentration; Q g The groundwater recharge rate (m) within this river section 3 / s·m).

[0088] Furthermore, the calculation of the process by which river water replenishes groundwater includes:

[0089] ;

[0090] in, The rate of river water seepage.

[0091] Furthermore, the calculation of the bidirectional conversion process between river water and groundwater includes:

[0092] ;

[0093] ;

[0094] Furthermore, the process of calculating the supply ratio includes:

[0095] When calculating the relative recharge ratio of groundwater to river water Or the proportion of river water seepage At that time, including:

[0096] ;

[0097] S3: After determining the physicochemical indicators, headspace analysis is used to extract dissolved N2O from the collected water and isotope analysis is performed to generate isotope analysis results.

[0098] Specifically, isotopes of nitrous oxide δ 15 N α and δ 18 O was determined using isotope ratio mass spectrometry. δ 15 N β and The value is calculated using the following formula:

[0099] ;

[0100] ;

[0101] Nitrous oxide is a triatomic asymmetric linear structure (NNO) composed of nitrogen (N) and oxygen (O). It has 12 isotopic isomers, five of which have distinct natural abundances. The nitrogen isotope in nitrous oxide can appear at the intermediate and terminal positions, respectively called... and , Intermolecular forces of nitrous oxide 15 N-site preference;

[0102] Stable isotope ratios are expressed as follows:

[0103] ;

[0104] in, Indicates the stable isotope ratio. and They are respectively 15 N / 14 N or 18 O / 16 O's sample and standard, reported δ 15 The N value is related to the nitrogen in the atmosphere, while δ 18 The O value is related to the Vienna standard mean seawater.

[0105] S4: After completing the isotope testing, an indoor culture experiment was conducted on the water sample to determine whether there was a non-biological source of nitrous oxide in the water sample, and the results of the indoor culture were generated.

[0106] Specifically, under anaerobic conditions, nitrates and nitrites are reduced with Fe... 2+ The coupled biological and abiotic processes of oxidation can generate large amounts of nitrous oxide. This process involves both microbial-mediated denitrification and chemical denitrification. To determine whether abiotic sources of nitrous oxide exist in the water and to provide a reliable local endmember range for subsequent Bayesian models, water samples were collected in the field for indoor incubation experiments. Considering that sterilization with ZnCl2 or NaOH would alter the physicochemical properties of the water, filtration was used to remove microorganisms from the water.

[0107] The specific process of removing microorganisms from water by filtration includes: First, in the field, a copper tube is inserted into the bottom of the serum bottle, and water sample is injected until it overflows by more than 3 times, and then sealed with an airtight butyl rubber stopper. The bottle is pre-cultured in an incubator (25°C) for 10 days until nitrates and nitrites are undetectable. After the pre-culture, the bottle is rinsed again with helium, and the water sample is divided into two groups: one group is sterilized by filtration through a 0.22 μm filter membrane for non-biological nitrous oxide generation experiments, and the other group is used for biological nitrous oxide generation experiments. Subsequently, the water sample is placed into a 100 mL serum bottle, rinsed with high-purity helium, and sealed with an airtight butyl rubber stopper. Three nitrogen treatments are added to each group of bottles: (1) control group without nitrogen (CK), (2) KNO3 added, and (3) KNO2 added. The concentration of nitrogen added depends on the nitrogen concentration of the water body collected. In this study, NO2 was added. - This study was not based on background concentration, but rather to quantify the contribution of chemical denitrification to nitrous oxide formation throughout the entire denitrification process. All bottles were incubated in darkness, at temperatures as close to in-situ as possible. At five time points—0 h, 12 h, 24 h, 36 h, and 48 h—10 mL of gas was replaced with helium to determine nitrous oxide concentration and isotope parameters, which are used for end-member values ​​required in later modeling. Specific measured parameters and their implications are as follows: Figure 4 As shown.

[0108] S5: Based on the results of the exchange ratio between river water and groundwater, isotope test results, and indoor culture results, the contribution of river nitrous oxide sources is quantified.

[0109] Specifically, the process of quantifying the contribution of river nitrous oxide sources includes delineating the sources of river nitrous oxide and quantifying the contribution of endogenous nitrous oxide processes. The process of delineating the sources of river nitrous oxide includes:

[0110] Assume that dissolved nitrous oxide in river water is divided into exogenous input and endogenous production: (1) exogenous supply (groundwater supply; upstream river input); (2) endogenous production (biological and abiotic processes). The calculation formula is as follows, using an isotope end-member mixing model:

[0111] ;

[0112] ;

[0113] in, , , , These are the characteristic values ​​of nitrous oxide isotopes from river dissolution, groundwater recharge, endogenous sources, and upstream river transport, respectively. , , All of these can be obtained through water sample collection and testing; the removal rate of nitrous oxide transport in groundwater and upstream rivers is not considered at this time. , and The figures represent the proportions of groundwater recharge and endogenous generation, and upstream river carryover, respectively, contributing to dissolved nitrous oxide at river sampling points. pass 222 The groundwater recharge ratio is obtained by calculating Rn.

[0114] Furthermore, the process of quantifying the contribution of endogenous nitrous oxide oxidation includes:

[0115] Assuming the main reactions in the nitrous oxide production process include: (1) microbial sources (bacterial denitrification) bD ), nitrifying bacteria denitrification ( nD ), fungal denitrification ( fD ) and nitration ( Ni (2) Non-biological processes Abio (This depends on the results of indoor cultivation). The contribution of different processes was then quantified using the FRAME model. The FRAME model is a Bayesian isotope mixing model based on the Markov Monte Carlo algorithm. This model defines the probability distribution of each pathway's contribution based on a stable isotope mixing model within a Bayesian framework, allowing uncertainty to be introduced into the input data and the confidence interval of the results to be evaluated. The model considers not only the mixing of nitrous oxide production pathways but also the fractionation effect of nitrous oxide reduction to N2. The main nitrous oxide production pathways involved in this model include: bD , nD , fD , Ni and AbioThe endmember values ​​for each generation pathway were obtained through culture experiments and literature. The fractionation effect conforms to the dynamic Rayleigh equilibrium equation within a closed system, as shown in the following equation:

[0116] ;

[0117] in, , , , , It represents the proportion of different reaction pathways that produce nitrous oxide. , , , , These are isotopic characteristic values ​​from different reaction pathways. r It is the residual of the proportion of unreduced nitrous oxide. A It is the isotopic fractionation coefficient of nitrous oxide reduction. μ The isotopic value representing the final nitrous oxide.

[0118] Example 2

[0119] Please see Figure 5 This invention provides a quantitative system for the contribution of river nitrous oxide sources and fate processes, comprising:

[0120] The data collection module 100 is used to collect surface water and groundwater to obtain water samples.

[0121] The physicochemical index determination module 200 is used to determine the physicochemical index of water samples. The physicochemical index determination includes: calculating and quantifying the exchange ratio between river water and groundwater.

[0122] The isotope testing module 300 is used to extract dissolved nitrous oxide from water samples after the physicochemical index determination is completed, and to perform isotope testing on the nitrous oxide to generate isotope test results.

[0123] The indoor culture module 400 is used to conduct indoor culture experiments on water samples after isotope testing to determine whether there are non-biological sources of nitrous oxide in the water samples and to generate indoor culture results.

[0124] The quantitative module 500 is used to quantify the contribution of river nitrous oxide sources based on the results of the exchange ratio between river water and groundwater, isotope test results, and indoor culture results.

[0125] The beneficial effects of the quantitative system for the contribution of river nitrous oxide sources and fate processes provided by this invention are as follows: Please refer to... Figure 2 and Figure 3 , Figure 2This diagram illustrates the overall framework of a quantitative method for assessing the contribution of river nitrous oxide sources and fate processes. Figure 3 This invention illustrates the sources and fate pathways of nitrous oxide. It effectively elucidates the sources and fate processes of nitrous oxide in rivers and accurately quantifies the contributions of different sources. This provides a high-precision accounting method for the global greenhouse gas inventory, supports the assessment of emission reduction targets, and offers a scientific basis for the coordinated management and ecological restoration of nitrogen pollution in polluted rivers, thereby promoting more precise watershed governance and global climate action.

[0126] The quantitative system for measuring the contribution of river nitrous oxide sources and fate processes in this embodiment of the invention can be a device, or a component, integrated circuit, or chip in a terminal. The device can be a mobile electronic device or a non-mobile electronic device. For example, mobile electronic devices can refer to mobile phones, tablets, laptops, PDAs, in-vehicle electronic devices, wearable devices, ultra-mobile personal computers (UMPCs), netbooks, or personal digital assistants (PDAs), etc., while non-mobile electronic devices can refer to servers, network-attached storage (NAS), personal computers (PCs), televisions (TVs), ATMs, or self-service machines, etc. This embodiment of the invention does not impose specific limitations.

[0127] The quantitative system for the contribution of river nitrous oxide sources and fate processes in this embodiment of the invention can be represented by a device with an operating system. This operating system can represent the Android operating system, the iOS operating system, or other possible operating systems; this embodiment of the invention does not specifically limit the scope.

[0128] The quantitative system for the contribution of river nitrous oxide sources and fate processes provided in this invention can achieve... Figures 1 to 4 The various processes implemented in the method embodiment of a quantitative method for the contribution of river nitrous oxide sources and fate processes will not be described again here to avoid repetition.

[0129] Optionally, embodiments of the present invention also provide an electronic device, including a processor, a memory, and a program or instructions stored in the memory and executable on the processor. When the program or instructions are executed by the processor, they implement the various processes of the above-described embodiment of a quantitative method for the contribution of river nitrous oxide sources and fate processes, and can achieve the same technical effects. To avoid repetition, they will not be described again here.

[0130] This invention also provides a readable storage medium storing a program or instructions that, when executed by a processor, implement the various processes of the above-described method embodiment for quantitatively determining the contribution of river nitrous oxide sources and fate processes, and achieve the same technical effect. To avoid repetition, these will not be described again here.

[0131] The processor refers to the processor in the electronic device described in the above embodiments. The readable storage medium includes computer-readable storage media, such as computer read-only memory (ROM), random access memory (RAM), magnetic disk, or optical disk.

[0132] It should be noted that, in this invention, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes that element. Furthermore, it should be noted that the scope of the methods and apparatus in the embodiments of this invention is not limited to performing functions in the order shown or discussed, but may also include performing functions substantially simultaneously or in the reverse order, depending on the functions involved. For example, the described methods may be performed in a different order than described, and various steps may be added, omitted, or combined. Additionally, features described with reference to certain examples may be combined in other examples.

[0133] Through the above description of the embodiments, those skilled in the art can clearly understand that the methods of the above embodiments can be implemented by means of software plus necessary general-purpose hardware platforms. Of course, they can also be implemented by hardware, but in many cases the former is a better implementation method. Based on this understanding, the technical solution of the present invention, or the part that contributes to the prior art, can be embodied in the form of a software product. This computer software product is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) and includes several instructions to cause a terminal (which may be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in the various embodiments of the present invention.

[0134] The embodiments of the present invention have been described above with reference to the accompanying drawings. However, the present invention is not limited to the specific embodiments described above. The specific embodiments described above are merely illustrative and not restrictive. Those skilled in the art can make many other forms under the guidance of the present invention without departing from the spirit and scope of the claims, and all of these forms are within the protection scope of the present invention.

Claims

1. A method for quantifying the contribution of riverine nitrous oxide source and sink processes, comprising: The method comprises the following steps: Collecting surface water and underground water to obtain water samples; Physicochemical index determination is performed on the water samples, and the physicochemical index determination comprises calculating the water exchange ratio of river water and underground water; After the physicochemical index determination is completed, dissolved oxidized nitrogen in the water samples is extracted, and isotope testing is performed on the oxidized nitrogen to generate isotope testing results; After the isotope testing is completed, indoor cultivation experiments are performed on the water samples to determine whether there is an abiotic process source of oxidized nitrogen in the water samples, and indoor cultivation results are generated; Based on the results of the river water and underground water exchange ratio, the isotope testing results and the indoor cultivation results, the contribution of river oxidized nitrogen sources is quantified; The process of quantifying the contribution of river oxidized nitrogen sources comprises dividing the sources of river oxidized nitrogen and quantifying the contribution of oxidized nitrogen endogenous processes, wherein the process of dividing the sources of river oxidized nitrogen comprises dividing the river oxidized nitrogen into exogenous supply and endogenous generation; the exogenous supply comprises underground water supply and upstream river input; the endogenous generation is derived from biological and abiological processes; The exogenous supply and endogenous generation are calculated by an isotope endmember mixing model, and the mathematical expression is as follows: ； ； Wherein, , , , respectively are the isotopic characteristic values of nitrous oxide dissolved in the river, groundwater recharge and endogenous production and carried by the upstream river, , , All can be obtained by collecting water samples for detection; temporarily not considering the removal rate of nitrous oxide transport process in groundwater and upstream river, , and respectively are the contribution proportion of groundwater recharge and endogenous production and the dissolved nitrous oxide in the sampling point of the river carried by the upstream river, The groundwater recharge proportion calculated by 222 Rn is obtained.

2. The method of claim 1, wherein the method is characterized by, The method comprises the following steps: Specific steps for obtaining water samples comprise: Surface water and underground water are collected along the river in different seasons, the different seasons comprise the wet season, the normal water period and the dry season, the flow rate and flow volume are determined on site by using a Doppler flow rate meter, the water depth is estimated by using the average value of the scale of three points uniformly distributed on the river cross section, the water temperature is determined on site by using a portable multi-parameter water quality monitor, and the water sample of indoor cultivation is stored at 4°C and quickly transported back to the laboratory.

3. The method of claim 1, wherein the method is characterized by, The isotopic test is also performed 222 The test of Rn activity, wherein the 222 The test of Rn activity, specifically includes: Take 100 ml water sample in brown glass bottle, on-site using radon meter test 222 Rn activity; The process of isotope testing specifically comprises: Dissolved nitrous oxide was collected on site using headspace method, and isotopes of nitrous oxide , δ 15 N α and δ 18 O were determined using isotope ratio mass spectrometer, and values were calculated according to the following equation: ； ； wherein the N isotope of nitrous oxide occurring in the middle position is called wherein the N isotope of nitrous oxide occurring in the terminal position is called , between nitrous oxide molecules 15 N site preference; The stable isotope ratio is represented as follows: ； wherein, represents a stable isotope ratio, and respectively are 15 N / 14 N or 18 O / 16 O of the sample and the standard; The process of calculating the water exchange ratio of river water and underground water comprises calculating the river water and underground water exchange flux, calculating the underground water supply to river water, calculating the river water supply to underground water, and calculating the supply ratio of river water and underground water bidirectional transformation, Specific steps for calculating the river water and underground water exchange flux comprise: The natural decay coefficient of radon isotope of river bed sediments and river water suspended particles is calculated based on the molecular diffusion coefficient, and the mathematical expression of the natural decay coefficient is as follows: ； wherein, represents 222 natural decay coefficient of Rn, represents river water flow rate, represents river water depth, represents radiation decay coefficient, represents 222 molecular diffusion coefficient of Rn, related to water temperature and the mathematical expression is: ； Specific steps for calculating the underground water supply to river water comprise: ； in, The upstream and downstream river waters are respectively 222 The concentration of Rn, These are the upstream and downstream river flows, respectively. This is the distance between the upstream and downstream sections. groundwater 222 The concentration of Rn, This represents the groundwater recharge rate within this river section. Specific steps for calculating the river water supply to underground water comprise: ； wherein, is the river water infiltration rate; Specific steps for calculating the river water and underground water bidirectional transformation comprise: ； ； Specific steps for calculating the supply ratio comprise: ； wherein, represents the relative recharge ratio of groundwater to river water, represents the river water leakage ratio.

4. The method of claim 1, wherein the method is characterized by, Specific steps for performing indoor cultivation experiments on the water samples comprise: A copper pipe is inserted into the bottom of a serum bottle, water sample is injected until it overflows by multiple times, and a gas-tight butyl rubber plug is used for sealing; The serum bottle is pre-cultured in a culture box for multiple days until nitrate and nitrite cannot be detected. After the pre-culture, the bottles were flushed again with helium and the water samples were split into two groups: one group was filtered sterilized using filter membranes and used for abiotic nitrous oxide production experiments, and the other group was used for biotic nitrous oxide production experiments; subsequently, the water samples were filled into serum bottles, flushed with helium and sealed with airtight butyl rubber stoppers, and three nitrogen treatments were added to each bottle in each group, respectively: a control group without nitrogen, KNO3 addition and KNO2 addition, and the nitrogen concentration added depends on the nitrogen concentration of the mine water body, wherein all bottles were cultured in the dark and as close to the original temperature conditions as possible, and 10 mL of gas was replaced at five time points of 0 h, 12 h, 24 h, 36 h and 48 h using helium for determination of nitrous oxide concentration and isotopic indicators.

5. The method of claim 1, wherein the method is characterized by, The specific process of quantifying the contribution of the endogenous process of nitrous oxide includes: Divide the reaction of the nitrous oxide production process into microbial sources and abiotic process sources to obtain the contribution of different processes; Quantify the contribution of the different processes to obtain a balance equation, wherein the mathematical expression of the balance equation is: ； wherein , , , , is the proportion of different reaction pathways of nitrous oxide production, , , , , is the isotopic signature of the different reaction pathways, r is the residual of the proportion of not reduced nitrous oxide, A is the isotopic fractionation coefficient of nitrous oxide reduction, μ represents the isotopic value of the final nitrous oxide.

6. A system for quantifying river nitrous oxide source and sink processes for implementing the method for quantifying river nitrous oxide source and sink processes according to any one of claims 1 to 5, characterized in that It includes: The collection module is used to collect surface water and groundwater to obtain water body samples; The physicochemical index determination module is used to determine the physicochemical indexes of the water body samples, and the physicochemical index determination includes calculating the river water and groundwater exchange ratio; The isotope testing module is used to extract dissolved nitrous oxide from the water body samples after the physicochemical index determination is completed, and the nitrous oxide is subjected to isotope testing to generate isotope test results; The indoor culture module is used to perform indoor culture experiments on the water body samples after the isotope testing is completed to determine whether there is an abiotic process source of nitrous oxide in the water body samples, and to generate indoor culture results; The quantification module is used to quantify the contribution of river nitrous oxide sources based on the results of the river water and groundwater exchange ratio, the isotope test results and the indoor culture results.

7. An electronic device, comprising: The processor, the memory and the program or instructions stored on the memory and executable on the processor are included, and the program or instructions are executed by the processor to implement the steps of the quantitative method of the river nitrous oxide source and the contribution of the process as claimed in any one of claims 1-5.

8. A readable storage medium, characterized by, The program or instructions are stored on the readable storage medium, and the program or instructions are executed by the processor to implement the steps of the quantitative method of the river nitrous oxide source and the contribution of the process as claimed in any one of claims 1-5.

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