Water environment ecological management method and system based on constructed wetland

Abstract

The invention relates to the technical field of water environment treatment, in particular to a water environment ecological treatment method and system based on a constructed wetland, and the method comprises the following steps: measuring the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value of a root zone in the constructed wetland, and calculating the pollutant concentration distribution value and plant root system distribution density of each monitoring point; and obtaining a water quality root distribution characterization value. In an artificial wetland environment, the concentration of dissolved oxygen, the concentration of ammonia nitrogen, the concentration of total phosphorus, the water temperature and the pH value of a root zone are measured, the concentration distribution of pollutants is calculated, numerical calculation is carried out in combination with the distribution density of plant root systems, water quality root system distribution characterization is constructed, spatial heterogeneity analysis of wetland water quality is enhanced, and the targeting of pollutant degradation is optimized. Based on water quality root system distribution characterization, plant growth cycle parameters are calculated in combination with water quality parameters, association between water quality dynamic changes and plant growth states is constructed, and the adaptability of wetland ecological regulation and control is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of water environment treatment, and particularly relates to a water environment ecological treatment method and system based on an artificial wetland. Background Art

[0002] Water environment ecological treatment mainly aims at treating polluted water bodies and ecological restoration. By means of hydraulic regulation, pollutant degradation, biological and ecological optimization and other measures, the water quality is improved, and the balance of the water ecosystem is adjusted to achieve the dual goals of pollution control and ecological restoration.

[0003] However, in the existing technology for water environment treatment, the removal of pollutants relies on static hydraulic regulation, lacking adaptive regulation based on the dynamic characteristics of water quality, resulting in a low matching degree in the degradation process of different pollutants and affecting the treatment effect. During the ecological restoration process, the monitoring of plant growth is not coupled with the water quality change, lacking the correlation analysis between the plant growth state and the pollutant degradation ability, resulting in a lag in the ecological regulation strategy. The influence of photosynthesis on water quality is only based on the overall assessment of the plant growth state, without considering the fluctuation of dissolved oxygen concentration during the photosynthesis period, resulting in the pollutant degradation potential during the photosynthesis enhancement period not being fully utilized. Therefore, improvements are needed. Summary of the Invention

[0004] The purpose of the present invention is to solve the deficiencies existing in the prior art, and to propose a water environment ecological treatment method and system based on an artificial wetland.

[0005] To achieve the above purpose, the present invention adopts the following technical solution. A water environment ecological treatment method based on an artificial wetland includes the following steps:

[0006] Measure the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value in the root zone of the artificial wetland, calculate the pollutant concentration distribution value and the plant root distribution density at each monitoring point, and obtain the water quality root distribution characterization value; based on the water quality root distribution characterization value, perform operations on the water quality parameters and the water quality root distribution characterization value to generate the wetland plant growth cycle parameters;

[0007] Collect plant leaf data to obtain the basic plant photosynthesis data; based on the basic plant photosynthesis data, record the water temperature change curve and the dissolved oxygen change curve during the photosynthesis period, and fit the photosynthesis intensity value and the dissolved oxygen change curve to generate the plant photosynthetic efficiency index;

[0008] Based on the wetland plant growth cycle parameters and the plant photosynthetic efficiency index, adjust the influent flow rate and the hydraulic retention time, measure the change range of the water quality parameters after adjustment to obtain the pollutant treatment dynamic value, and based on the pollutant treatment dynamic value, calculate the pollutant removal amount per unit area and the plant biomass growth rate to establish the wetland operation control threshold;

[0009] Based on the wetland operation control threshold, divide the wetland water inlet period and the static period, measure the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the plant root zone during different periods, and calculate and generate the wetland system operation parameters.

[0010] The present invention provides a water environment ecological governance system, including:

[0011] A water quality root monitoring module measures the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value in the root zone in the constructed wetland, calculates the pollutant concentration distribution value and the plant root distribution density according to the data of each monitoring point, and obtains the water quality root characterization value;

[0012] A photosynthetic efficiency analysis module, based on the water quality root characterization value, collects plant leaf data, records the water temperature change curve and the dissolved oxygen change curve during the photosynthesis time period, fits the photosynthesis intensity value and the dissolved oxygen change curve, and generates a plant photosynthetic efficiency index;

[0013] An ecological regulation module, based on the plant photosynthetic efficiency index, adjusts the water inlet flow rate and the hydraulic retention time, measures the change of the water quality parameters after adjustment, calculates the pollutant removal amount per unit area and the plant biomass growth rate, and establishes a wetland operation control threshold;

[0014] A pollutant dynamic analysis module, based on the wetland operation control threshold, divides the wetland water inlet period and the static period, and measures the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the plant root zone during different periods again to obtain the pollutant treatment dynamic value;

[0015] A system operation parameter module calculates and generates the wetland system operation parameters based on the pollutant treatment dynamic value.

[0016] Compared with the prior art, the advantages and positive effects of the present invention are as follows:

[0017] In the constructed wetland environment, by measuring the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature, and pH value in the root zone, calculating the pollutant concentration distribution, and performing numerical operations in combination with the plant root distribution density, a water quality root distribution characterization is constructed to strengthen the spatial heterogeneity analysis of wetland water quality and optimize the targeting of pollutant degradation. Based on the water quality root distribution characterization, by calculating the plant growth cycle parameters in combination with water quality parameters, an association between the dynamic changes in water quality and the plant growth state is constructed to improve the adaptability of wetland ecological regulation. By extracting plant leaf data, recording the changes in water temperature and dissolved oxygen during the photosynthesis period, and establishing a fitting relationship between the photosynthesis intensity and the change in dissolved oxygen, the contribution of photosynthesis to pollutant degradation is quantitatively analyzed. Based on the plant growth cycle parameters and photosynthetic efficiency indicators, the influent flow rate and hydraulic retention time are adjusted, the change range of water quality parameters after adjustment is measured, and a dynamic value for pollutant treatment is constructed to enable the water quality regulation to have a dynamic response ability and optimize the synergistic relationship between the hydraulic retention time and pollutant degradation. In combination with the dynamic value for pollutant treatment, the pollutant removal amount per unit area and the plant biomass growth rate are calculated, and an operating control threshold for the wetland is established to link the pollutant degradation ability with the plant growth process and make the wetland operation mechanism ecologically adaptable. According to the operating control threshold, the wetland influent period and static period are divided, the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the plant root zone at different periods are measured, and the wetland system operation parameters are calculated to make the wetland operation strategy adapt to the rhythm of water quality changes and improve the pollutant degradation efficiency and ecological balance ability of the wetland. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a schematic diagram of the steps of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0019] In order to make the objectives, technical solutions, and advantages of the present invention clearer and more understandable, the present invention will be further described in detail below in conjunction with the drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0020] Please refer to Figure 1 , the present invention provides a technical solution, a water environment ecological governance method based on a constructed wetland, including the following steps:

[0021] Measure the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature, and pH value in the root zone of the constructed wetland, calculate the pollutant concentration distribution value and plant root distribution density at each monitoring point to obtain the water quality root distribution characterization value; based on the water quality root distribution characterization value, perform operations on the water quality parameters and the water quality root distribution characterization value to generate the plant growth cycle parameters of the wetland;

[0022] Collect plant leaf data to obtain basic plant photosynthesis data; based on the basic plant photosynthesis data, record the water temperature change curve and dissolved oxygen change curve during the photosynthesis time period, fit the photosynthesis intensity value and the dissolved oxygen change curve, and generate a plant photosynthetic efficiency index;

[0023] Based on the wetland plant growth cycle parameters and the plant photosynthetic efficiency index, adjust the influent flow rate and hydraulic retention time, measure the change range of water quality parameters after adjustment to obtain the dynamic pollutant treatment value, and based on the dynamic pollutant treatment value, calculate the pollutant removal amount per unit area and the plant biomass growth rate to establish a wetland operation control threshold;

[0024] Based on the wetland operation control threshold, divide the wetland influent time period and the static time period, measure the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the plant root zone during different time periods, and calculate and generate wetland system operation parameters.

[0025] The steps for obtaining the water quality root distribution characterization value are as follows:

[0026] Deploy monitoring equipment inside the constructed wetland, regularly measure the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature, and pH value in the root zone, collect the water quality data of each monitoring equipment to obtain the original water quality data set;

[0027] Based on the original water quality data set, calculate the pollutant-root composite distribution value, and the calculation formula is:

[0028]

[0029] where C di represents the pollutant concentration at the i-th monitoring point, D i represents the corresponding root distribution density, and P i is the pollutant-root composite distribution value at the i-th monitoring point;

[0030] Based on the pollutant-root composite distribution value, calculate the water quality root distribution characterization value, and the calculation formula is:

[0031]

[0032] where P i represents the pollutant-root composite distribution value at the i-th monitoring point, W i represents the weight factor at the i-th monitoring point, n is the total number of monitoring points, and Q is the water quality root distribution characterization value.

[0033] Specifically, monitoring devices are deployed in the constructed wetland, and the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature, and pH value in the root zone are recorded one by one, and the sampling time is marked. According to the device identification, each record is corresponding to the corresponding geographical location. For example, the monitoring results of water temperature are tested in the range of 0°C to 60°C, the dissolved oxygen concentration is tested in the range of 0 mg / L to 15 mg / L, the ammonia nitrogen concentration is tested in the range of 0 mg / L to 50 mg / L, and the total phosphorus concentration is tested in the range of 0 mg / L to 5 mg / L. If the detected value exceeds the corresponding range, the operation data of the manual comparison monitoring instrument is executed and the device is replaced or calibrated. When data loss is found, the records in the adjacent time period at the same location are compared to mark the available data for subsequent calculation. After confirming that the data at each monitoring location is valid and the time is aligned, they are arranged in the order of sampling time, and corresponding location information is configured for each sampling information to form corresponding monitoring records. Then, the records of all monitoring locations are merged into a data file for later analysis, and finally the original water quality data set is obtained.

[0034] The benefit of the formula is that by integrating the pollutant concentration and the plant root distribution density, the water quality index is combined with the root growth characteristics to characterize the comprehensive pollution intensity and root action characteristics of each monitoring point, so as to provide more targeted evaluation results for the decision-making of subsequent water environment ecological governance.

[0035] C di The steps for obtaining the parameter are as follows: First, sensors that can record indicators such as ammonia nitrogen concentration and total phosphorus concentration are set at each monitoring point in the constructed wetland. Each time a record is made, the dissolved oxygen concentration and the concentration values of various pollutants are stored separately and sorted according to the sampling time sequence. Then, according to the detection principles of ammonia nitrogen and total phosphorus, the colorimetric method and the spectrophotometric method are used to measure the concentration values of ammonia nitrogen and total phosphorus respectively. The data outside the ranges of ammonia nitrogen concentration from 0 mg / L to 50 mg / L and total phosphorus concentration from 0 mg / L to 5 mg / L are manually verified and abnormal results are excluded. Then, the records that match the detection of ammonia nitrogen and total phosphorus concentrations are selected from the processed data, and these concentration values are merged with other pollutant concentration information to obtain C di , for example, if the measured ammonia nitrogen concentration at a monitoring point is 32.1 mg / L and the total phosphorus concentration is 2.47 mg / L, after combining other trace pollutant concentration data and unifying the units, they are added up to obtain C di , in this example, by adding up the concentration values of all detected pollutants such as 24.59 mg / L, 32.1 mg / L, 2.47 mg / L, etc., and excluding the invalid records among them, C di = 59.16 mg / L is obtained as the pollutant concentration value of this monitoring point.

[0036] D iThe parameter acquisition steps are as follows: using the root observation tube pre-buried in the wetland and combining it with the image acquisition equipment, the growth image data of the plant roots at the corresponding monitoring points are collected every 48 hours, and the total projection area of ​​the roots in the observation area of ​​the sampling tube is identified by the image processing method, and then compared with the reference area of ​​the observation area to obtain the root distribution density value, and the root distribution density of all observation periods is recorded in a sequence. For example, the root image collected at a certain monitoring point is processed to obtain a root projection area of ​​5.6 cm2, and the reference area of ​​the observation tube is 8.0 cm2, then the root distribution density can be calculated as 5.6 / 8.0=0.70. If the results of multiple recordings are 0.64, 0.68, 0.70, 0.73, etc., the values ​​of the nodes at similar time points can be averaged or interpolated, and finally 0.70 is used as the D value of this period. i .

[0037] Calculation process:

[0038] The first step is to calculate For example, if the pollutant concentration C at a monitoring point in this period is di =59.16, root distribution density D i =0.70, then:

[0039]

[0040] The second step is to take the square root to get P i :

[0041]

[0042] The results show that for this monitoring point, the composite distribution value formed by the combined effect of pollutant concentration and root distribution density is about 59.24. The larger the value, the more obvious the pollutant load and the higher the corresponding root distribution density. It can be used for subsequent analysis and comparison of water quality root distribution characterization. i The values ​​are sorted or clustered to determine their relative position in the overall water quality status.

[0043] The benefit of the formula is that it combines the pollutant-root composite distribution value of each monitoring point with the corresponding weight factor, and by taking the square root of the weight factor, it moderately balances the differences among the monitoring points, so that the final water quality root distribution characterization value can reflect the average level of the overall pollutant load and root distribution status.

[0044] P i The parameter acquisition step is to directly select the calculated pollutant-root composite distribution value for further weighted calculation of this formula. There is no need to obtain it repeatedly here. Just use the previously obtained P i value.

[0045] W i The steps for obtaining the parameter are as follows: Assign a weight with a value range between 1 and 10 to each monitoring point. This weight is set according to factors such as the geographical location of the monitoring point within the wetland, the plant growth situation, and the distance to the external sewage outlet. For each weight value, it is necessary to first collect the distance between the monitoring point and the sewage outlet, the historical average pollutant concentration of the monitoring point, and the root zone activity index. After comparing these data, calculate the ratios respectively, and then divide the sum result by several reference coefficients to obtain the final value. For example, for a monitoring point that is closer to the sewage outlet and has a higher historical average concentration, the value is larger. If the distance of the monitoring point from the sewage outlet is 150m, the historical average concentration is 30.22mg / L, and the root zone activity index obtained by image recognition is 0.72, then the three values can be normalized accordingly and added together, and then divided by 1.87 to obtain the corresponding weight of 7.2, and it is updated regularly during the monitoring period.

[0046] The steps for obtaining the n parameter are as follows: Count the total number of monitoring points and ensure that all monitoring point data are complete and valid during the calculation. For example, if there are currently 20 monitoring locations deployed in the wetland and the observation records are complete, then n = 20. If the data of individual monitoring points are missing during a certain period, they need to be excluded or filled before calculation.

[0047] Calculation process:

[0048] The first step is to sum For example, select 3 sample values from 20 monitoring points: The first monitoring point P 1 = 59.24 and W 1 = 7.2, the second monitoring point P 2 = 42.85 and W 2 = 5.6, the third monitoring point P 3 = 65.47 and W 3 = 9.1, then:

[0049]

[0050] If the results of all monitoring points are added up in sequence to get (including the total values of the remaining 17 monitoring points), then in this example, this sum value is 2210.30.

[0051] The second step is to divide by the total number of monitoring points n. In this example, take n = 20, and get:

[0052]

[0053] The results show that the water quality root distribution characterization value comprehensively obtained from 20 monitoring points during the selected period of the example is approximately 110.515. If this value is calculated for subsequent periods and compared with the previous results, the changes in the overall pollutant load and root growth of the constructed wetland can be further judged by the numerical increase or decrease trend and whether it exceeds a certain management threshold.

[0054] The steps to obtain the growth cycle parameters of wetland plants are as follows:

[0055] According to the water quality root distribution characterization value, calculate the wetland plant growth cycle index, and the calculation formula is:

[0056]

[0057] Among them, Q is the water quality root distribution characterization value, T i is the water temperature at the i-th monitoring point, H i is the pH value, S i is the dissolved oxygen concentration, and G is the wetland plant growth cycle index;

[0058] Based on the wetland plant growth cycle index, combined with the ammonia nitrogen concentration and total phosphorus concentration, perform cycle fitting to form the wetland plant growth cycle parameters.

[0059] Specifically, the advantage of the formula lies in integrating the water quality root distribution characterization value with the key data directly reflecting the plant growth environment, such as water temperature, pH value, and dissolved oxygen concentration. A multiplication and division relationship is established through the form of summation and taking the square root of the sum of squares in the denominator, and finally a non-linear adjustment is made with a power of 0.8, so that the calculation result can more sensitively capture the changes in the wetland plant growth cycle.

[0060] The steps to obtain the Q parameter are based on the water quality root distribution characterization value obtained previously.

[0061] T i The steps to obtain the parameter are as follows: Continuously record the water temperature values near the monitoring point, and the range is generally between 5°C and 40°C. Associate these water temperature values with the specific time axis, and after excluding the records outside this range or with abnormal jumps, screen out the temperature values in the stable section, store them in the water temperature sequence in the form of separate modeling for each monitoring point, and then extract the temperature values matching the required period for cycle calculation as T i , for example, record the water temperature every 3 hours during daily observations. The data measured at monitoring point B for multiple consecutive days are between 17.2°C and 22.9°C, and take the average value of 20.4°C in the corresponding period as T for a certain calculation. i .

[0062] H iThe steps for obtaining the parameters are as follows: measure the pH value of the corresponding monitoring point through an online pH sensor and record it in a list corresponding to the monitoring time. Before each measurement, first compare the pH sensor with a known standard solution to confirm that the measurement error does not exceed 0.1. Then, eliminate the abnormal measurement points from the processed data and form a reliable pH sequence. Next, intercept the pH values suitable for cycle calculation from the corresponding time period as H i , for example, the pH values measured at monitoring point C multiple times last week were between 6.7 and 7.4. The record with relatively stable values and no outliers was intercepted to obtain 7.1 as H for this calculation i .

[0063] S i The steps for obtaining the parameter are as follows: obtain it according to the online detection results of the dissolved oxygen concentration at the monitoring point. Each monitoring point is measured multiple times at least during the day-night alternation period, and the measurement range is generally between 0.5 mg / L and 12 mg / L. After eliminating the instantaneous shocks or abnormal values, take the average value of the dissolved oxygen data during the stable period and regard this average value as S i , for example, the dissolved oxygen concentrations detected at monitoring point D within a day and night were mostly between 5.5 mg / L and 8.3 mg / L. The average value obtained by sampling 4 times at night and 4 times during the day was 6.4 mg / L, so this value can be used as S for the current time period i .

[0064] Substituting into the formula for calculation gives 91.58. This result indicates that the wetland plant growth cycle index for this time period is 91.58. The larger the value, the higher the adaptability of the plants in the wetland to the external environment and the faster the growth trend. If this value gradually decreases to around 50 in subsequent time periods, further adjustment in water environment management can be considered. If it continuously approaches or exceeds 120, it means significant plant proliferation, and more detailed monitoring and management of the growth status of wetland plants are required

[0065] When performing periodic fitting by combining the obtained wetland plant growth cycle index G with the ammonia nitrogen concentration and total phosphorus concentration acquired within the same monitoring period, first collect the daily records of the ammonia nitrogen concentration and total phosphorus concentration during the monitoring period, accumulate them at intervals of once every three hours, and form a concentration sequence within the monitoring period. Check the ammonia nitrogen concentration within the range of 0 mg / L to 50 mg / L and review the records that significantly exceed the range. Compare the total phosphorus concentration within the range of 0 mg / L to 5 mg / L, compare the detection data with this range one by one and mark them as qualified or exceeding the standard. When there are multiple consecutive exceedances or approaching the upper limit value, increase the detection frequency in the subsequent time periods. After forming an effective concentration sequence, jointly compare the periodic change trends of ammonia nitrogen and total phosphorus with the wetland plant growth cycle index G obtained previously, establish a time series model to analyze the repeated fluctuation degree of ammonia nitrogen and total phosphorus within each day and even each week, select polynomial fitting or piecewise cubic spline fitting methods for curve matching, thereby identify the peak points and trough points, match the G values corresponding to each peak point and trough point, identify the growth cycle state of the plants within the corresponding time periods, and finally make associated records of the fluctuation segments or stable segments and the G values in the curve fitting results to comprehensively obtain the wetland plant growth cycle parameters; the specific method for establishing the time series model is as follows: Continuously collect the time series data of the ammonia nitrogen concentration and total phosphorus concentration within the monitoring period and record them at hourly or shorter intervals. First, form a sequence of each record in chronological order, and then perform mean centering and standard deviation normalization processing to ensure the comparability of indicators with different numerical scales. Select the ARIMA(2,1,2) model for modeling in combination with the historical observation sample size, where p = 2 indicates tracing back two steps forward, d = 1 indicates performing a first-order difference on the sequence, and q = 2 indicates that the model contains two moving average terms. Subsequently, use the least squares method to perform initial estimation of each parameter, calculate the residual sequence and evaluate the white noise characteristics, determine whether the residuals meet the requirement of no correlation through the Ljung-Box test, observe the autocorrelation function and partial autocorrelation function to fine-tune the values of p and q, correct the model parameters according to the fitting results and repeat the training until it converges to a lower error level and meets the ability to stably interpret the sequence, and finally generate a reliable time series model.

[0066] The steps for obtaining the plant photosynthetic efficiency index are as follows:

[0067] Collect chlorophyll fluorescence parameters, photosynthetically active radiation, and net photosynthetic rate, integrate them and perform denoising and normalization to form a basic plant photosynthesis dataset;

[0068] Based on the basic plant photosynthesis dataset, record the water temperature change curve and dissolved oxygen change curve during the photosynthesis time period to establish photosynthesis time series data;

[0069] Based on the time series data of photosynthesis, calculate the photosynthetic efficiency index of plants. The calculation formula is as follows:

[0070]

[0071] Among them, E is the photosynthetic efficiency index of plants, and F t is the photosynthesis intensity, O t is the dissolved oxygen concentration, L t is the photosynthetically active radiation, T t is the water temperature, and t 0 to t 1 is the photosynthesis recording time period.

[0072] Specifically, when collecting chlorophyll fluorescence parameters, photosynthetically active radiation, and net photosynthetic rate, it is necessary to place the optical sensors used for detection above the wetland plant community at regular intervals in advance, and obtain the time series data of photosynthetically active radiation in the mode of continuous monitoring for 8 hours every day. For the detection of net photosynthetic rate, it depends on the gas analysis equipment to record the change amount of carbon dioxide concentration in the gas around the plants during a specific period. At the same time, use the spectral analyzer to detect the fluorescence emission peak of the plant leaves, pair the collected fluorescence signals and radiation intensity data, and use the most basic sliding window method to perform differential calibration on the fluctuations of the signal curves one by one, and then clean the potential outliers in the way of point-by-point comparison. If it exceeds the acceptable range defined by the system multiple times during a certain period (for example, if the photosynthetically active radiation is lower than 10 μmol / m2·s or higher than 2000 μmol / m2·s), then further intensive sampling will be carried out in the subsequent several detections, so as to obtain more recorded chlorophyll fluorescence parameters and net photosynthetic rate at finer time points. After that, compare all the collected records item by item, exclude the obviously unreasonable data generated by equipment failures, and when normalizing the remaining data, use the minimum and maximum values of the photosynthetically active radiation as the standard reference, and also map the fluorescence intensity and net photosynthetic rate to the 0-1 interval, so as to unify the data dimensions between different observation positions and different time periods. Finally, after normalization, merge and output to a unified data table, and by arranging the data table in chronological order, a basic plant photosynthesis dataset can be formed.

[0073] Based on the obtained basic plant photosynthesis dataset, it is necessary to record the water temperature change curve and dissolved oxygen change curve during the photosynthesis period. The water temperature detection device is set near the root system and the value is recorded every 30 minutes. The dissolved oxygen detection device is placed in the same area and a set of sensors in the range of 0 mg / L to 15 mg / L is used for tracking. If the detected results of dissolved oxygen are continuously close to 15 mg / L in some periods, the recording frequency is increased to once every 10 minutes according to the encryption detection strategy. At the same time, the water temperature and dissolved oxygen data are corresponding to the same time scale and linearly interpolated to ensure that the two curves have corresponding values at each time point. When there are data missing in some intervals, the adjacent previous and subsequent valid records are referred to. When there are less than two data references, on-site inspections and supplementary measurements are carried out. After obtaining relatively complete water temperature change curves and dissolved oxygen change curves through such time-by-time sorting methods, the two are respectively detected for large-amplitude jump points. For example, the water temperature mutation exceeds 3 °C or the dissolved oxygen mutation exceeds 5 mg / L. When this situation occurs, continue to compare and detect the records in the subsequent periods. When the water temperature and dissolved oxygen data of all periods are integrated in chronological order, they are marked and sorted synchronously as two time series, and finally the photosynthesis time series data is established.

[0074] The advantage of the formula is that it utilizes the product relationship between the photosynthesis intensity and the dissolved oxygen concentration, and increases the influence of dissolved oxygen in this product in the form of the 1.3 power. At the same time, the sum of the square of the photosynthetically active radiation and the water temperature is integrated in the denominator to represent the influence of external environmental factors. Finally, the overall result is adjusted by the 0.9 power, so that the calculated plant photosynthetic efficiency index can more sensitively reflect the dynamic changes under different environmental conditions.

[0075] Parameter F t The acquisition steps of are as follows. First, the photosynthesis intensity near the plant leaves is recorded in real time within the selected time range. The photosynthesis intensity can be reflected by measuring the carbon dioxide consumption rate or oxygen release rate, and can also be compared with the effective photosynthesis efficiency data generated in chlorophyll fluorescence detection. The original recorded values of this photosynthesis intensity are arranged in chronological order and abnormal peaks are removed. Then, these records are resampled or interpolated according to each time point interval (for example, one record every 10 minutes). Finally, a continuous F t distribution sequence is ensured within the range from t0 to t1. For example, from 8:00 to 18:00, one sample is taken every 10 minutes, and 60 records can be obtained in a day. If one of the records is too different from the previous and subsequent ones, on-site detection and verification are carried out again, and it is corrected or removed. Finally, it is summarized into an F t data table. For example, in the actual monitoring of a certain day, this sequence may remain around 1.5 in the initial period (the unit can be mgCO 2 / (L·h), 5.2 appears at the noon peak and gradually drops to 2.7 in the afternoon, etc.

[0076] Parameter O t The acquisition steps of are as follows: continuously monitor through a dissolved oxygen sensor placed in the water body, and record the measured value as O at every 10-minute interval. t If the range of the dissolved oxygen sensor is 0 mg / L to 15 mg / L, it is necessary to monitor that the actual detection data does not exceed the range. At the same time, before each sampling, conduct an instrument comparison according to the standard saturated dissolved oxygen value. After collecting the complete records, eliminate the abnormal points and synchronize them with F t corresponding time to form O with the same number of nodes. t sequence. For example, between 8:00 and 18:00, O t is relatively low in the morning at 4.1 mg / L, rises to 8.6 mg / L at noon, and drops to 5.3 mg / L again in the afternoon. After converting these data sequences into discrete time sequences in units of 10 minutes, it is convenient for point-by-point calculation during subsequent integration operations.

[0077] Parameter L t The acquisition steps of are as follows: utilize the photosynthetically active radiation detection information obtained previously, conduct segmented statistics on the observed data of effective radiation during the same period (8:00 - 18:00), correspond the recorded value every 10 minutes to the specific time, and then eliminate the records in the unreasonable range (such as below 10 μmol / m2·s or above 2000 μmol / m2·s) and pair them with F t and O t to form the L t sequence. For each moment, if the observed effective radiation value is within the acceptable range, directly use this value as L t , and finally, all the L t at all moments form a time series. For example, in the initial stage, the photosynthetically active radiation may be only 50 μmol / m2·s, rise to 1800 μmol / m2·s at noon, and then fall back to about 400 μmol / m2·s in the afternoon. At this time, a relatively complete L t sequence can be formed.

[0078] Parameter T t The acquisition steps of are as follows: continuously monitor using a water temperature sensor during the selected time period, record once every 10 minutes, and keep the temperature value (unit: °C) consistent with the previous time node to form the T t sequence. At this time, it is necessary to ensure that the actual detection results are within a reasonable range (such as 5 °C to 40 °C). For data that may show jumps, conduct a water temperature comparison or additional temperature measurements to exclude abnormal readings, and finally synchronize with O t and F tand L t After alignment, they are uniformly formed into a multi-column data table. For example, the water temperature is stable at 17 °C in the morning, gradually rises to 23 °C at 1 pm, and drops to 21 °C after 5 pm. Arranging these discrete time values can obtain T t .

[0079] Parameter t 0 and t 1 The acquisition steps are as follows: Manually set the photosynthesis recording time period. Usually, it can be selected from after sunrise to afternoon according to the observation needs, or specific time periods in the low-light environment at night can be studied. For example, to adapt to the growth of wetland plants, t 0 = 8, t 1 = 18. By continuously recording F t , O t , L t , T t at each node within these 10 hours, a time series data with full coverage is formed. When it is necessary to change or subdivide the time period later, new t 0 and t 1 can be defined in other daily time periods in the same way and data can be collected again. In this example, t 0 = 8, t 1 = 18 is just one selection method. Users can also select different time periods by themselves in combination with the real-time monitoring situation, as long as it is ensured that the corresponding observed data can be completely matched with the time nodes.

[0080] Calculation process:

[0081] The first step is to solve the numerator . In actual operation, discrete integration is often used for approximate calculation. For example, from 8 o'clock to 18 o'clock, it is divided into 10 hours in total, and each hour is further divided into 6 nodes (one node every 10 minutes), then 60 pairs of (F t , O t ) values can be obtained. Add up the at each node and multiply by the time step (here the time step is 10 minutes = 1 / 6 hour), and the integral result can be obtained. For example, if the sum after calculation at each node is 590.24 and the time step is 0.1667 hour, then the numerator is approximately 590.24×0.1667≈98.38.

[0082] The second step is to calculate the denominator . The same number of nodes can also be used. Square and sum L t and T t at each moment respectively. For example, at 60 nodes, accumulate point by point to get Then the denominator is

[0083] In the third step, raise the ratio of the numerator to the denominator obtained in the previous step to the 0.9th power:

[0084]

[0085] E = 0.407 0.9 ≈0.43

[0086] This result indicates that the plant photosynthetic efficiency index during this period is approximately 0.43. If the monitoring personnel find that this value is close to or exceeds 1 after continuous calculations for multiple days, it means that the coupling between the photosynthesis intensity and the dissolved oxygen concentration increases. If it is lower than 0.2, it indicates that the photosynthesis and dissolved oxygen performance are relatively low during the defined time period. It is possible to combine the previously obtained F t and O t and other sequences for other aspects of analysis.

[0087] The steps to obtain the dynamic value of pollutant treatment are as follows:

[0088] Based on the wetland plant growth cycle parameters and the plant photosynthetic efficiency index, analyze the impact of different growth stages on water quality regulation, and combine the wetland hydraulic characteristics to establish the inlet flow rate adjustment parameters;

[0089] According to the inlet flow rate adjustment parameters, calculate the hydraulic retention time of the water body in the wetland, combine the water quality root distribution characterization value, simulate the water body flow path, analyze the pollutant diffusion trend, and generate the hydraulic retention time adjustment parameters;

[0090] Based on the hydraulic retention time adjustment parameters, adjust the wetland inlet flow rate and hydraulic retention time, measure the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the root zone after adjustment in real time, calculate the change range of the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the root zone, and obtain the dynamic value of pollutant treatment.

[0091] Specifically, based on the wetland plant growth cycle parameters and plant photosynthetic efficiency indicators, first, the corresponding plant growth stage information is compared with the previously obtained plant photosynthetic efficiency indicators. The wetland plant growth cycle parameters at each monitoring point in the water body during corresponding time periods are divided into different categories such as the initial growth period and the rapid growth period. The records of water quality parameters during these different time periods are retrieved point by point. For example, during the initial growth period, the fluctuation ranges of dissolved oxygen and ammonia nitrogen concentrations in the root zone can be concentrated at relatively low levels. During the rapid growth period, the dissolved oxygen will increase relatively. At the same time, combined with data on the water flow path, flow velocity distribution, and actual positions of the inlet and outlet in the wetland hydraulic characteristics, the absorption and retention of pollutants such as ammonia nitrogen and total phosphorus by the water body passing through different vegetation areas are compared one by one. The daily monitoring records of indicators such as dissolved oxygen, ammonia nitrogen, and total phosphorus are compared with the vegetation growth stages, and the results of these data comparisons are summarized into a time period - growth stage correspondence table. Subsequently, possible water quality fluctuation areas are divided in the comparison table according to the flow velocity and water depth. For example, ammonia nitrogen is not easily absorbed in the sparse vegetation section, and the dissolved oxygen may be relatively high in the rapid growth period section. Using this information, the average pollutant concentration when the water depth at each monitoring point is between 0.1 m and 0.5 m and the water flow velocity is between 0.01 m / s and 0.1 m / s is statistically calculated in the software, and the difference between this average value and the average value of the adjacent time period is compared. If a significant difference or an exceedance of the existing experience threshold occurs (such as when comparing the ammonia nitrogen concentration in the range of 0 mg / L to 50 mg / L, and it is marked that intervention is required when the upper limit of 50 mg / L is approached in three consecutive detections), the influent flow rate is refined and adjusted in the subsequent steps. Next, after obtaining such statistical results, considering factors such as the base flow rate and microtopography conditions at the wetland inlet and outlet, the specific timing and amplitude for appropriately increasing or decreasing the influent are comprehensively analyzed. Finally, the influent flow rate settings that can match different growth stages are summarized. In this way, a lower influent rate can be maintained in some time periods while the influent rate is increased in other time periods. These values are recorded item by item to form the influent flow rate adjustment parameters.

[0092] According to the previously generated influent flow rate adjustment parameters, the hydraulic retention time of the water body in the wetland is calculated each time the influent rate changes. The specific method is to first collect the effective water volume and cross-sectional area of each partition in the wetland. By combining this information with the actual influent rate, cumulative or segmented calculations are performed for different flow directions and sections passed through, forming a set of corresponding relationships between time periods and hydraulic retention times. At this time, if the hydraulic retention time of a certain section is close to or greater than the specified range (for example, an empirical range is 2 hours to 8 hours, and when it exceeds 8 hours continuously for multiple times, it is marked as a high retention risk area), then in subsequent stages, it may be necessary to reduce the influent or introduce a diversion route. Then, further combining the water quality root distribution characterization value on this basis, the hydraulic retention time corresponding to the section with a higher plant root density is compared with the hydraulic retention time corresponding to the section with a lower density to obtain the pollutant diffusion trend in different sections. For example, ammonia nitrogen and total phosphorus will be absorbed more quickly in the high root density section, while concentration accumulation may occur in the low root density section. The monitoring records of three pollutants, dissolved oxygen, ammonia nitrogen, and total phosphorus, are listed item by item for these two extreme cases and mapped to the retention time. If the pollutant diffusion speed in a certain section is much greater than the vegetation absorption speed, then this section is marked as an object that needs to strengthen flow rate control in the record. Further, simulation operations are carried out to increase the flow rate or decrease the hydraulic retention time in these sections. For example, when the average value of dissolved oxygen decreases successively and the ammonia nitrogen concentration increases successively in a section, the influent flow rate parameter is decreased by 5% and measured again, and new time period - hydraulic retention time data are obtained in turn. Finally, these discrete results obtained through repeated adjustments are combined and output as several reference points, and finally recorded as the hydraulic retention time adjustment parameters.

[0093] Adjust parameters based on the hydraulic retention time. First, set continuous monitoring points at the wetland inlet and outlet respectively. Compare the measured flow values with the adjusted time period - hydraulic retention time correspondence relationship in the previous step, re - compare the time taken for water bodies to pass through the wetland in different time periods, and measure the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the root zone in real - time after each modification of the influent flow. If a certain index during the detection is close to the upper limit of the empirical threshold (for example, ammonia nitrogen is close to 50 mg / L), immediately correct the influent flow again. If the dissolved oxygen is stable in the range of 6 mg / L to 9 mg / L and the ammonia nitrogen and total phosphorus concentrations are within reasonable ranges during the detection, maintain the original influent velocity and continue to monitor. During this process of cyclic recording, take the difference between the influent flow, the corresponding hydraulic retention time, and the three key indicators after each adjustment. For example, observe that the dissolved oxygen concentration increases by 1 mg / L compared with before the adjustment, and the ammonia nitrogen concentration decreases by 5 mg / L. Compare these change amplitudes with the previous records respectively. If the same - direction changes occur continuously for several times, it is determined that a relatively stable purification effect can be obtained at this flow adjustment level. Finally, summarize the difference values of the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in multiple time periods, and perform average or weighted evaluation to obtain a comprehensive pollutant removal rate sequence, thereby obtaining the dynamic value of pollutant treatment.

[0094] The steps to obtain the wetland operation control threshold are as follows:

[0095] Analyze the pollutant degradation rate per unit area, extract the degradation characteristics of different pollutant types, and construct pollutant removal data per unit area in combination with the dynamic value of pollutant treatment.

[0096] According to the pollutant removal data per unit area, calculate the growth rate of plant biomass, analyze the contribution rate of photosynthesis to biomass accumulation in combination with the plant photosynthetic efficiency index, and generate plant biomass growth rate data in combination with the wetland plant growth cycle parameters.

[0097] Based on the plant biomass growth rate data, calculate the wetland operation control threshold. The calculation formula is:

[0098]

[0099] where Y is the wetland operation control threshold, R a is the pollutant removal amount per unit area, G b is the plant biomass growth rate, S n is the change amplitude of water quality parameters, and P m is the total wetland biomass.

[0100] Specifically, analyze the pollutant degradation rate per unit area. After obtaining the pollutant concentration change data at different monitoring points in detail, divide it into several fixed area units, so as to record the degradation rates of ammonia nitrogen, total phosphorus and other trace pollutants in each area unit over time. If the pollutant concentration shows large fluctuations in some sections due to geographical characteristics or vegetation coverage differences, it is necessary to identify multiple geographical areas separately and track and record the actual degradation rates within the areas. Then, classify and sort pollutants such as ammonia nitrogen and total phosphorus within each geographical area. For example, extract multiple detection records of them throughout the day or within two days respectively, align these records with time and regard the same type of pollutants as the same group. For example, when the ammonia nitrogen record exceeds a certain empirical threshold of 50 mg / L, it is specially marked during statistics to distinguish high-pollution concentration samples from conventional concentration samples. Then, divide the decline trend of pollutant concentration during the statistical process into intervals. For example, divide 24 hours into several 6-hour or 3-hour sections, and judge the specific degradation rate per unit area by comparing the ammonia nitrogen and total phosphorus values in different periods. During the process, monitoring outliers need to be excluded. After each period is completed, take the difference from the result of the previous period. For example, if ammonia nitrogen drops from 45 mg / L to 39 mg / L, record the degradation amount of 6 mg / L in this interval, and accumulate and average multiple adjacent periods to obtain the average degradation rate per unit area of the corresponding section. Subsequently, further extract the degradation characteristics of different pollutants based on these degradation rates. For example, statistically calculate the average degradation amount of ammonia nitrogen when the temperature is between 25°C and 30°C and the water depth is between 0.3 m and 0.5 m, and the average degradation amount of total phosphorus in the area with dense plant roots, etc. Combine these monitoring results to gradually construct a data set of pollutant classification degradation characteristics. Finally, correlate this data with the pollutant treatment dynamic values obtained previously, compare the removal amount and accumulation amount of pollutants per unit area in each period segment by segment, and determine the changes in the pollutant accumulation or removal trends under different area units and different periods through a unified marking method. Finally, aggregate to obtain the pollutant removal data per unit area.

[0101] Based on the pollutant removal data per unit area obtained previously, when calculating the plant biomass growth rate, it is necessary to utilize the regular monitoring records of plants. For example, the height and canopy coverage of the vegetation in the wetland are periodically detected by means of random sampling in different zones, and the actual plant mass at different monitoring points is obtained by combining the dry matter determination method. These records are arranged in chronological order and outliers are excluded. For example, if there are special weather conditions or strong winds that cause excessive plant toppling, supplementary measurements are carried out again in the subsequent period. Then, the biomass accumulation of plants per hour or per day is calculated by comparing the dry mass of the vegetation at the beginning and end stages. For example, if the dry mass of the plants detected in a section increases from 2.5 kg / m² in the previous period to 2.8 kg / m², it has increased by 0.3 kg / m² in one week. After that, the contribution ratio of photosynthesis to this part of the dry matter accumulation is evaluated by combining the previously obtained plant photosynthetic efficiency index. The records of the photosynthetic efficiency index in the same week are corresponded one by one with the increment of the vegetation dry mass, and the removal effects of pollutants such as ammonia nitrogen and total phosphorus are compared in the statistical table. For example, by comparing the records of dissolved oxygen, ammonia nitrogen concentration and total phosphorus concentration every day, if a relatively fast biomass growth rate is observed when the ammonia nitrogen concentration is maintained in the range of 20 mg / L to 25 mg / L, this phenomenon is recorded in the growth cycle parameter data. Finally, on the basis of multiple statistics and comparisons, the biomass accumulation rate in all monitoring periods is summarized, the regression analysis of the relationship between photosynthesis efficiency and biomass growth is carried out and recorded in the final data list to obtain the plant biomass growth rate data.

[0102] The advantage of the formula is that it combines the pollutant removal amount per unit area and the plant biomass growth rate at the same time. Through the three-dimensional correlation of the change range of water quality parameters and the total wetland biomass, multiple key indicators in the wetland operation management process are calculated uniformly. And through the embedding of logarithmic and sine functions, as well as the non-linear processing of the cube root in the denominator part, the result can more flexibly meet the needs of dynamic wetland ecosystem management.

[0103] R aThe steps to obtain the parameters are as follows: First, using the pollutant removal data per unit area obtained previously, for major pollutants such as ammonia nitrogen and total phosphorus, calculate the total removal amount within a certain period in the same area unit, and divide it by the area value corresponding to this area unit to obtain the pollutant removal amount per unit area. If the wetland is divided into multiple geographical regions, it is necessary to calculate the removal amount per unit area of each region separately and compare them within the same time interval, and then take the average between similar intervals or perform weighted combination according to actual monitoring requirements. For example, in a partition with an area of 500 m2, the total ammonia nitrogen removal amount within a week is 12,000 mg. Divide 12,000 mg by 500 m2 to get 24 mg / m2. If 220 mg of total phosphorus is also removed in this partition, it can be recorded as 220 / 500 = 0.44 mg / m2. Finally, after converting and summing up the comprehensive removal amounts of major pollutants per unit area according to the same index, compare these removal amount sequences or take the representative value of a certain period to obtain R a , for example, after final summary and averaging, R a = 24.44 mg / m2.

[0104] G b The steps to obtain the parameters are as follows: Through the calculated plant biomass growth rate data, first classify and denoise the multi-period measurement results to eliminate the interference of abnormal factors such as sudden climate, and retain a relatively balanced growth curve. Then, divide the increment of biomass at each time period by the time in terms of dry matter weight or fresh weight to obtain the growth rate sequence per hour or per day. Take the multi-day biomass growth rate sequences within the same section and average them to obtain the representative value of G b in the typical period of this section. For example, in the 30-day monitoring record, the average biomass of wetland plants increased from 3.1 kg / m2 to 4.0 kg / m2, so the increase in one month is 0.9 kg / m2. If converted to per day, it is 0.03 kg / m2, denoted as G b = 0.03 kg / m2·d. Finally, according to needs, it can also be converted to per hour or finer-grained data, such as 0.03 / 24 = 0.00125 kg / m2·h, etc.

[0105] S n The steps to obtain the parameters are as follows: First, extract the change ranges of dissolved oxygen, ammonia nitrogen, total phosphorus, etc. from the historical records of water quality detection within the same monitoring period, calculate the span from the initial value to the peak or trough, take the maximum change amount and record it as the change amplitude of water quality parameters. For example, within a certain monitoring period, ammonia nitrogen fluctuates from 15 mg / L to 33 mg / L, and the difference of 18 mg / L is regarded as part of the change amplitude of this round. If the dissolved oxygen also changes from 6 mg / L to 10 mg / L, with a change of 4 mg / L, then in the comprehensive comparison, the average difference of all key indicators or a similar method may be used to obtain S n, for example, during this period, the comprehensive calculation of the differences in dissolved oxygen, ammonia nitrogen, and total phosphorus is 22.5 mg / L as agreed, denoted as S n = 22.5. If it is necessary to calculate multiple times in multiple periods, the change amplitudes in different periods can be weighted or aggregated, and one S value is taken for each period n value, and finally, the amplitude value that best represents the current operation period is selected.

[0106] P m The steps for obtaining the P parameter are as follows. To express the overall biomass scale of the wetland, it is necessary to comprehensively measure from multiple aspects such as the plant density, root coverage, and surface plant coverage in the partitioned areas. For example, by regularly collecting plants in multiple representative areas and measuring their dry matter weights, the results are extrapolated to the entire wetland, and kg or t is used as the measurement unit. For example, in a wetland with a total area of 10,000 m2, after multiple spot checks, the estimated dry mass of the plants is about 2.4×10 6 kg. Then, at this time, P m = 2.4×10 6 kg.

[0107] Calculation process:

[0108] In the first step, first calculate ln(R a +1). For example, taking the aforementioned R a = 24.44 mg / m2, then:

[0109] ln(24.44 + 1) = ln(25.44) ≈ 3.24

[0110] In the second step, calculate sin(G b ). If G b = 0.03 kg / m2·d, then:

[0111] sin(0.03) ≈ 0.03

[0112] In the third step, take the difference and the absolute value:

[0113] |ln(25.44) - sin(0.03)| = |3.24 - 0.03| = 3.21

[0114] In the fourth step, calculate For example, selecting S n = 22.5 and P m = 2.4×10 6 , then:

[0115]

[0116] In the fifth step, thus obtain Y:

[0117]

[0118] The result shows that the calculated wetland operation control threshold at this time is about 0.0239. When it is subsequently monitored that the threshold fluctuates significantly, for example, rises above 0.05 or drops below 0.01, it may be necessary to further check and adjust in combination with the pollutant removal amount per unit area or the biomass growth rate obtained previously. If the difference between ln(R a +1) and sin(G b ) decreases significantly in the subsequent period, it means that the dynamic balance between the pollutant removal amount and the plant growth rate tends to change. And if it increases continuously with the total wetland biomass, it is necessary to comprehensively evaluate the impact degree of this value on the overall threshold.

[0119] The steps for obtaining the wetland system operation parameters are as follows:

[0120] Based on the wetland operation control threshold, analyze the water quality fluctuation trend, determine the hydraulic retention characteristics in different time periods, divide the wetland influent time period and the static time period, and establish the data for dividing the wetland influent time period and the static time period;

[0121] According to the data for dividing the wetland influent time period and the static time period, measure the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the plant root zone, adjust the sensor measurement interval, record the water quality parameters in different time periods, analyze the parameter change trend, summarize the data characteristics, and generate the water quality parameter data for different time periods;

[0122] Based on the water quality parameter data for different time periods, calculate the change range of the water quality parameters, analyze the change patterns of the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the influent time period and the static time period, and generate the wetland system operation parameters in combination with the wetland operation control threshold.

[0123] Specifically, based on the wetland operation control threshold, it is necessary to continuously observe the changes in water quality status during different periods, compare the recent fluctuations of key indicators such as dissolved oxygen, ammonia nitrogen, and total phosphorus with the previously obtained wetland operation control threshold. If it is found that the dissolved oxygen has been maintained in the range of 6 mg / L to 8 mg / L and the ammonia nitrogen has been detected close to 50 mg / L multiple times during a certain observation period, it can be judged that there may be a high-load risk in this section. At this time, under the dispatching of the operator, calculate and record the hydraulic retention time of this section, and calibrate the observation time window in combination with the flow rate and hydraulic retention time information in the existing wetland flow configuration plan. Compare these monitoring and calculation results item by item. If significant changes occur in the dissolved oxygen and ammonia nitrogen data after extending or shortening the retention time, mark the corresponding relationship between this change and the operation control threshold. After confirming that the data of all key monitoring sections have been recorded and compared with the pre-established effective range, screen out the relatively stable water quality periods and the periods with large fluctuations in turn. On this basis, combine the observation records of the geographical location of the monitoring points, the plant growth cycle, and the photosynthesis intensity, split or merge several originally adjacent or overlapping periods according to the high or low retention characteristics, and finally form a corresponding table of period-retention characteristics. Mark the periods at high-load risk as the inlet periods prone to pollution fluctuations, and mark the relatively stable periods with an obvious pollutant degradation trend as the static periods. When the hydraulic retention characteristics of all sections are completed, integrate these records into the data for dividing the wetland inlet periods and static periods.

[0124] According to the data divided by the wetland water inlet period and the static period, it is necessary to detect the dissolved oxygen concentration, ammonia nitrogen concentration, and total phosphorus concentration in the plant root zone at different times, and adjust the sensor measurement frequency at intervals set in advance by the management personnel. If a certain section is judged to be prone to high-load risks in previous analyses, the monitoring interval will be shortened to 30 minutes or less. If the corresponding section has been stable within the specified range in multiple recent detections, such as the dissolved oxygen being between 5mg / L and 9mg / L, and the ammonia nitrogen being between 10mg / L and 25mg / L, the measurement interval can be relaxed to 1 hour or 2 hours. When the monitoring officially starts, the measured data will be compared with the average value of the same type of period one by one. For example, during a 6-hour water inlet period, the dissolved oxygen in the root zone is recorded every half hour, and each record is compared with the range of 4mg / L to 10mg / L. If three consecutive records show values less than 4mg / L or greater than 10mg / L, the detection interval will be further shortened in the subsequent period, and the ammonia nitrogen and total phosphorus conditions will be recorded, and this section will be marked as an abnormal fluctuation period. For the static period, the operator can check whether there is an accumulated change in dissolved oxygen and ammonia nitrogen on the basis of detecting once per hour. If it is observed that the ammonia nitrogen has increased by more than 5mg / L compared to the previous period, this phenomenon will be recorded in the parameter change table. After all observations are completed, the dissolved oxygen, ammonia nitrogen, and total phosphorus data in different periods will be summarized, and the corresponding values will be subtracted or averaged to summarize the increase or decrease of each period index, and finally the water quality parameter data of different periods will be generated.

[0125] Based on the water quality parameter data of different periods, first, the initial measured value and the last measured value are respectively selected from the dissolved oxygen, ammonia nitrogen, and total phosphorus values obtained in each period for comparison to obtain the change range of each period. During this process, abnormal measured values are excluded or rechecked, and it is confirmed that they have indeed fluctuated significantly before being included in the difference sequence. Then, the difference distribution observed during the water inlet period is compared with the corresponding difference distribution during the static period. If the ammonia nitrogen reduction amount in a certain period exceeds 10mg / L while it is only about 2mg / L during the static period, it indicates that the ammonia nitrogen treatment in this water inlet period is relatively obvious within the monitored section. If there are also some periods in which the total phosphorus is detected to gradually increase in the range of 2mg / L to 5mg / L, further monitoring needs to be strengthened in the subsequent periods. Next, these comparison results are associated with the wetland operation control thresholds obtained previously, and the change range values of ammonia nitrogen and total phosphorus in the same period are written into the threshold comparison table. If it is found that it has approached or exceeded a previously set threshold, such as 50mg / L, a corresponding warning mark will be made. Finally, all the water quality change records of the water inlet period and the static period are summarized, combined with the threshold comparison results obtained in the previous step, to obtain the wetland system operation parameters.

[0126] The present invention provides a water environment ecological governance system, including:

[0127] The water quality root monitoring module measures the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value in the root zone within the constructed wetland, calculates the pollutant concentration distribution value and the plant root distribution density based on the data of each monitoring point, and obtains the water quality root characterization value;

[0128] The photosynthetic efficiency analysis module, based on the water quality root characterization value, collects plant leaf data, records the water temperature change curve and the dissolved oxygen change curve during the photosynthesis time period, fits the photosynthesis intensity value and the dissolved oxygen change curve, and generates the plant photosynthetic efficiency index;

[0129] The ecological regulation module, based on the plant photosynthetic efficiency index, adjusts the influent flow rate and the hydraulic retention time, measures the change of the water quality parameters after adjustment, calculates the pollutant removal amount per unit area and the plant biomass growth rate, and establishes the wetland operation control threshold;

[0130] The pollutant dynamic analysis module, based on the wetland operation control threshold, divides the wetland influent time period and the static time period, and measures the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the plant root zone again during different time periods to obtain the pollutant treatment dynamic value;

[0131] The system operation parameter module calculates and generates the wetland system operation parameters based on the pollutant treatment dynamic value.

[0132] The above is only the preferred embodiment of the present invention, and it is not intended to limit the present invention in other forms. Any person skilled in the art may use the disclosed technical content to make changes or modifications into equivalent embodiments with equivalent changes and apply them to other fields. However, any simple modification, equivalent change and modification made to the above embodiments based on the technical essence of the present invention without departing from the technical solution content of the present invention still fall within the protection scope of the technical solution of the present invention.

Claims

1. A water environment ecological management method based on artificial wetlands, characterized in that: The following steps are involved: Measuring the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value in the root zone in the artificial wetland, calculating the pollutant concentration distribution value and the plant root distribution density at each monitoring point, and obtaining the water quality root distribution characterization value; based on the water quality root distribution characterization value, calculating the water quality parameters and the water quality root distribution characterization value to generate the wetland plant growth cycle parameters; Collect plant leaf data to obtain basic photosynthetic data of the plant; based on the basic photosynthetic data of the plant, record the water temperature change curve and the dissolved oxygen change curve within the photosynthesis time period, fit the photosynthesis intensity value and the dissolved oxygen change curve, and generate a plant photosynthetic efficiency index; Based on the wetland plant growth cycle parameters and plant photosynthetic efficiency index, the water inlet flow rate and hydraulic retention time are adjusted, the change range of the water quality parameters after adjustment is measured, and the dynamic value of pollutant treatment is obtained. Based on the dynamic value of pollutant treatment, the pollutant removal amount per unit area and the plant biomass growth rate are calculated to establish a wetland operation control threshold; Based on the wetland operation control threshold, the wetland is divided into a water inflow period and a static period, the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the plant root zone in different time periods are measured, and the wetland system operation parameters are calculated and generated.

2. The water environment ecological management method based on artificial wetlands according to claim 1 is characterized in that: The steps for obtaining the water quality root distribution characterization value are as follows: Deploy monitoring equipment in the artificial wetland to regularly measure the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value in the root zone, collect water quality data from each monitoring device, and obtain the original water quality data set; Calculating pollutant-root system composite distribution values ​​based on the original water quality data set; Based on the pollutant-root system composite distribution value, the water quality root system distribution characterization value is calculated.

3. The water environment ecological management method based on artificial wetlands according to claim 1 is characterized in that: The steps for obtaining the growth cycle parameters of the wetland plants are as follows: Calculating a wetland plant growth cycle index according to the water quality root distribution characterization value; Based on the wetland plant growth cycle index, combined with ammonia nitrogen concentration and total phosphorus concentration, cycle fitting is performed to form wetland plant growth cycle parameters.

4. The water environment ecological management method based on artificial wetlands according to claim 1 is characterized in that: The steps for obtaining the plant photosynthetic efficiency index are as follows: Chlorophyll fluorescence parameters, photosynthetically active radiation and net photosynthetic rate were collected, integrated, denoised and normalized to form a basic data set of plant photosynthesis; Based on the plant photosynthesis basic data set, record the water temperature change curve and dissolved oxygen change curve within the photosynthesis time period to establish photosynthesis time series data; Based on the photosynthesis time series data, a plant photosynthetic efficiency index is calculated.

5. The water environment ecological management method based on artificial wetlands according to claim 1 is characterized in that: The steps for obtaining the dynamic value of pollutant treatment are: Based on the wetland plant growth cycle parameters and plant photosynthetic efficiency index, the influence of different growth stages on water quality regulation is analyzed, and the water inflow regulation parameters are established in combination with the wetland hydraulic characteristics; Calculate the hydraulic retention time of the water body in the wetland according to the water inflow flow adjustment parameter, simulate the water flow path in combination with the water quality root distribution characterization value, analyze the pollutant diffusion trend, and generate the hydraulic retention time adjustment parameter; Based on the hydraulic retention time adjustment parameters, the wetland water inflow rate and hydraulic retention time are adjusted, the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the root zone after adjustment are measured in real time, the change range of the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the root zone is calculated, and the dynamic value of pollutant treatment is obtained.

6. The water environment ecological management method based on artificial wetlands according to claim 1 is characterized in that: The steps for obtaining the wetland operation control threshold are: Analyze the degradation rate of pollutants per unit area, extract the degradation characteristics of different types of pollutants, and construct pollutant removal data per unit area in combination with the dynamic values ​​of pollutant treatment; Calculate the plant biomass growth rate based on the pollutant removal data per unit area, analyze the contribution of photosynthesis to biomass accumulation in combination with the plant photosynthetic efficiency index, and generate plant biomass growth rate data in combination with the wetland plant growth cycle parameters; Based on the plant biomass growth rate data, the wetland operation control threshold is calculated.

7. The water environment ecological management method based on artificial wetlands according to claim 1 is characterized in that: The steps for obtaining the operating parameters of the wetland system are as follows: Based on the wetland operation control threshold, the water quality fluctuation trend is analyzed, the hydraulic retention characteristics of different time periods are determined, the wetland water inflow period and the static period are divided, and the wetland water inflow period and static period division data are established; Divide the data according to the water inflow period and the static period of the wetland, measure the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the plant root zone, adjust the sensor measurement interval, record the water quality parameters in different periods, analyze the parameter change trend, summarize the data characteristics, and generate water quality parameter data in different periods; Based on the water quality parameter data of the different time periods, the variation range of the water quality parameters is calculated, the variation patterns of dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration during the water inlet period and the static period are analyzed, and the wetland system operation parameters are generated in combination with the wetland operation control threshold.

8. The water environment ecological management system according to any one of claims 1 to 7, characterized in that: include: The water quality root system monitoring module measures the dissolved oxygen concentration, ammonia nitrogen concentration, total phosphorus concentration, water temperature and pH value in the root zone in the artificial wetland, calculates the pollutant concentration distribution value and plant root distribution density based on the data of each monitoring point, and obtains the water quality root system characterization value; The photosynthetic efficiency analysis module collects plant leaf data based on the water quality root system characterization value, records the water temperature change curve and dissolved oxygen change curve during the photosynthesis period, fits the photosynthesis intensity value and the dissolved oxygen change curve, and generates the plant photosynthetic efficiency index; The ecological control module adjusts the water flow and hydraulic retention time based on the plant photosynthetic efficiency index, measures the changes in water quality parameters after adjustment, calculates the pollutant removal per unit area and the plant biomass growth rate, and establishes the wetland operation control threshold; The pollutant dynamic analysis module divides the wetland into water inflow period and static period based on the wetland operation control threshold, and measures the dissolved oxygen concentration, ammonia nitrogen concentration and total phosphorus concentration in the plant root zone in different periods to obtain the dynamic value of pollutant treatment; The system operation parameter module calculates and generates the wetland system operation parameters based on the dynamic values ​​of pollutant treatment.

Images