Method and device for testing maturity of compost

Abstract

The invention discloses a compost maturity testing method and a compost maturity testing device. The compost maturity testing method provided by the invention comprises the following steps: acquiring the electron exchange capability of a first compost sample; inputting the electron exchange capability into a seed germination index prediction model to obtain a seed germination index output by the seed germination index prediction model; the seed germination index prediction model is obtained based on sample data training, and the sample data comprises historical electron exchange capability of a second compost sample and corresponding compost time thereof, and historical seed germination indexes of the second compost sample and corresponding compost time thereof; and evaluating the compost maturity based on the seed germination index. According to the method, the seed germination index prediction model is established, and the seed germination index can be calculated only by measuring the electron exchange capacity of the sample in the actual testing process, so that the composting process can be rapidly measured on site, and the compost maturity can be accurately evaluated.

Description

Technical Field

[0001] The present invention belongs to the technical field of environmental treatment, and particularly relates to a method and a device for testing the maturity of compost. Background Art

[0002] Aerobic composting is the most widely used technology for the treatment and resource utilization of organic solid waste at home and abroad. This process has many advantages such as low investment, low operating cost, and good harmless effect. The produced organic fertilizer has a high nutrient content and active substances, which provide energy and nutrients for the activities of soil microorganisms, promote the growth of crops and improve the quality of agricultural products. After organic solid waste is composted, it must be matured before it can be used to produce organic fertilizer. When unripe compost is applied to the soil, it can cause intense activities of microorganisms, resulting in a lack of oxygen, thus leading to an anaerobic environment. At the same time, a large number of intermediate metabolites (organic acids, NH3, H2S, etc.) will be produced, which seriously poison the roots of plants and affect the normal growth of crops. In addition, the odor emitted by unripe compost is likely to cause secondary pollution to the environment.

[0003] At present, there are mainly three categories of indicators for evaluating the maturity of compost: (1) Physical indicators: characteristics such as temperature, color, and odor. (2) Chemical indicators: carbon-nitrogen ratio, organic matter, humification, fluorescence spectrum, infrared spectrum, etc. (3) Biological indicators: seed germination. The above indicators can comprehensively reflect the practicability of compost and are generally used to judge the stability of compost. Among many evaluation indicators, the seed germination index is considered to be the most persuasive method for evaluating the harmless maturity of compost products. The seed germination index comprehensively reflects the phytotoxicity of compost and is considered to be the most sensitive and reliable evaluation index for compost maturity. However, the traditional method for testing the seed germination rate takes at least one week, with a long testing time. Moreover, since there are many parameters involved in seed germination, for example, high-quality seeds have a high germination rate, while poor-quality seeds may not germinate, which directly leads to misjudgment of the test results.

[0004] At present, the specific technologies for testing the maturity of compost using the above indicators are as follows: using a fluorescence spectrometer to scan the sample and identifying the maturity of compost by distinguishing the characteristic functional groups of compounds through fluorescence; comprehensively judging the maturity of compost by obtaining near-infrared spectra, chemical indicators, and germination rates; reflecting the maturity of compost by measuring the electron supply ability in the compost sample; measuring the two-dimensional and three-dimensional fluorescence spectra of the sample, and analyzing the sample in combination with the LM neural network model to obtain the maturity level of the sample.

[0005] The indicators measured by the above methods are relatively single, and most of the instruments used for measurement are large-scale measurement instruments, with a long measurement time and a large workload, having a large delay, and it is difficult to integrate them into a real-time and portable rapid measuring instrument, and cannot guide the on-site composting work in real time and quickly.

[0006] Therefore, it is necessary to find a small, real-time, and fast compost maturity test method that can reflect comprehensive indicators and can be portably assembled. Summary of the Invention

[0007] In order to overcome at least one of the above-mentioned problems existing in the prior art, one of the objectives of the present invention is to provide a method for testing the maturity of compost, which has a fast testing speed, accurate test results, and can be used to test the maturity of compost in real time and quickly.

[0008] Another objective of the present invention is to provide a device for testing the maturity of compost.

[0009] A third objective of the present invention is to provide an electronic device.

[0010] In order to achieve the above objectives, the technical solutions adopted by the present invention are as follows:

[0011] The first aspect of the present invention provides a method for testing the maturity of compost, including:

[0012] Obtaining the electro-exchange capacity of a first compost sample;

[0013] Inputting the electro-exchange capacity into a seed germination index prediction model to obtain a seed germination index output by the seed germination index prediction model, and evaluating the compost maturity based on the seed germination index; the seed germination index prediction model is trained based on sample data, and the sample data includes the historical electro-exchange capacity of a second compost sample and its corresponding composting time, as well as the historical seed germination index of the second compost sample and its corresponding composting time.

[0014] The technical principle of the present invention is as follows: During the aerobic composting process, as the composting time progresses, the seed germination rate index gradually increases. Therefore, it can be obtained that there is a certain positive correlation between the seed germination rate index and the composting time. In addition, as the composting process progresses, the water-soluble organic matter in the compost sample gradually increases. These organic matters contain many electron groups such as quinone groups, which have redox capabilities and can supply electrons or accept exogenous electrons. The electron-donating ability and electron-transferring ability of water-soluble organic matter are collectively referred to as electro-exchange capacity. As the composting time progresses, the electro-exchange capacity of water-soluble organic matter gradually increases. Therefore, it can be obtained that there is a certain positive correlation between the electro-exchange capacity and the composting time. Based on the above relationships, the present invention selects the historical seed germination index and the historical electro-exchange capacity as important indicators. Based on the positive correlation between both of them and the composting time, a seed germination index prediction model is established. During the actual testing process, only by measuring the electro-exchange capacity of the sample, the seed germination index can be calculated, so as to perform on-site and rapid measurement of the composting process and accurately evaluate the compost maturity.

[0015] In the present invention, the second compost sample may be the same as or different from the first compost sample. Specifically, the second compost sample may be a compost sample having the same or similar types of raw materials as the first compost sample, so that the seed germination index prediction model has a more accurate seed germination index prediction result for a compost sample having the same or similar types of raw materials.

[0016] In some embodiments of the present invention, the historical seed germination index of the second compost sample is selected from the seed germination indices having a consistent correlation with the calibration index of the second compost sample; the calibration index of the second compost sample includes physical indices, chemical indices or a combination thereof of the second compost sample.

[0017] Since the seed germination index is greatly affected by other factors such as seed quality, calibrating the seed germination index and then using it as the historical seed germination index for model construction can improve the prediction accuracy.

[0018] In some specific embodiments of the present invention, the criterion for having a consistent correlation may be that the value of the correlation coefficient ≥ 0.9, specifically, it may be 0.9, 0.95 or 0.99.

[0019] In some more specific embodiments of the present invention, the physical indices include at least one of temperature, color or odor.

[0020] In some more specific embodiments of the present invention, the chemical indices include at least one of carbon-nitrogen ratio, organic matter content, humus content, fluorescence spectrum or infrared spectrum; specifically, the humus content may be at least one of fulvic acid (FA) content and humic acid (HA) content; the fluorescence spectrum may be selected from three-dimensional fluorescence spectra.

[0021] Using chemical indices and physical indices to correct biological indices, thereby comprehensively evaluating the degree of compost maturity, and the indices can be measured on-site in real time and quickly.

[0022] In some embodiments of the present invention, obtaining the electron exchange capacity of the first compost sample includes: obtaining the relationship curve of the current and time of the first compost sample, and performing area integration on the relationship curve of the current and time of the first compost sample to obtain the electron exchange capacity of the first compost sample;

[0023] Obtaining the historical electron exchange capacity of the second compost sample includes: obtaining the relationship curve of the current and time of the second compost sample, and performing area integration on the relationship curve of the current and time of the second compost sample to obtain the historical electron exchange capacity of the second compost sample.

[0024] By performing area integration on the current-time relationship curve of the first compost sample or the second compost sample, the historical electron exchange capacity of the first compost sample or the second compost sample can be obtained quickly and simply.

[0025] In some specific embodiments of the present invention, obtaining the current-time relationship curve of the first compost sample includes: mixing the first compost sample, an electrolyte, and a solvent, passing a first current, and measuring the current-time relationship curve of the first compost sample;

[0026] Obtaining the current-time relationship curve of the second compost sample includes: mixing the second compost sample, an electrolyte, and a solvent, passing a second current, and measuring the current-time relationship curve of the second compost sample.

[0027] In some more specific embodiments of the present invention, the potential for passing the first current is 0.3 - 0.8V; for example, it can be 0.3, 0.5, 0.8V, etc.;

[0028] and / or, the potential for passing the second current is 0.3 - 0.8V; for example, it can be 0.3, 0.5, 0.8V, etc.

[0029] In some embodiments of the present invention, the electron exchange capacity of the obtained first compost sample and the seed germination index of the first compost sample can be used as sample data to correct and improve the seed germination index prediction model.

[0030] In some embodiments of the present invention, the first compost sample and the second compost sample each independently include at least one of the following compost raw materials: sludge, feces, biogas residue. Specifically, the feces can be at least one of pig manure, chicken manure, and cow manure; more specifically, the compost raw materials may further include a bulking agent, such as at least one of rice husk, wood chips, and straw.

[0031] In some specific embodiments of the present invention, the equation of the seed germination index prediction model is:

[0032] GI = f(A) (1)

[0033] A = f(t) (2)

[0034] where GI is the seed germination index, A is the electron exchange capacity, and t is the composting time.

[0035] The second aspect of the present invention provides a test device for compost maturity, including:

[0036] An electron exchange capacity acquisition module for acquiring the electron exchange capacity of the first compost sample;

[0037] A seed germination index prediction module is configured to input the electronic exchange capacity into a seed germination index prediction model to obtain a seed germination index output by the seed germination index prediction model, and evaluate the compost maturity based on the seed germination index. The seed germination index prediction model is trained based on sample data, which includes the historical electronic exchange capacity of a second compost sample and the corresponding composting time, as well as the historical seed germination index of the second compost sample and the corresponding composting time.

[0038] A third aspect of the present invention provides an electronic device, including a processor and a memory storing computer program instructions. When the processor executes the computer program instructions, the method for testing the compost maturity as described in the first aspect of the present invention is implemented.

[0039] The beneficial effects of the present invention are as follows: The present invention selects the historical electronic exchange capacity of the compost sample and the corresponding composting time, as well as the historical seed germination index and the corresponding composting time as sample data. Both the historical electronic exchange capacity and the historical seed germination index of the compost sample have a positive correlation with the composting time. Using the composting time as an intermediate variable, a seed germination index prediction model is established. During the actual testing process, only by measuring the electronic exchange capacity of the sample, the seed germination index can be calculated, thereby enabling on-site and rapid determination of the composting process and accurately evaluating the compost maturity.

[0040] Specifically, compared with the prior art, the present invention has the following advantages:

[0041] (1) The present invention comprehensively combines physical property indicators, biological indicators, and chemical indicators, and comprehensively reflects the maturity degree of the compost.

[0042] (2) The present invention adopts a small-component design and can be integrated into a portable instrument, thereby realizing on-site real-time monitoring and timely guiding production.

[0043] (3) The present invention overcomes the disadvantage of long testing time of large instruments such as traditional spectrometers and chemical testers. By using the method of on-site electrochemical signals and data equations, it has the advantages of short testing time and high efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic diagram of the device structure of Embodiment 1 of the device of the present invention.

[0045] Figure 2 It is a schematic diagram of the test principle and process of Embodiment 1 of the device of the present invention.

[0046] Figure 3 It is a relationship curve of the electronic exchange capacity and the composting time, and the seed germination index and the composting time in Embodiment 1 of the method of the present invention.

[0047] Figure 4 This is the curve of the electronic exchange capacity and the composting time, and the curve of the seed germination index and the composting time in Example 2 of the method of the present invention.

[0048] Figure 5 This is the curve of the electronic exchange capacity and the composting time, and the curve of the seed germination index and the composting time in Example 3 of the method of the present invention. Detailed implementation manners

[0049] The content of the present invention will be further described in detail through specific embodiments below. It should also be understood that the following embodiments are only used to further illustrate the present invention and cannot be construed as limiting the protection scope of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the principles described in the present invention fall within the protection scope of the present invention. The specific process parameters and the like in the following examples are also only an example within a suitable range, that is, those skilled in the art can make selections within a suitable range through the description herein, rather than being limited to the specific data in the following examples. The raw materials, reagents or devices used in the following examples and comparative examples can be obtained from conventional commercial channels or can be obtained by existing known methods without special instructions.

[0050] Device Embodiment 1

[0051] A test device for compost maturity, the structural schematic diagram is as Figure 1 shown, and the test principle and process schematic diagram are as Figure 2 shown. The test device includes:

[0052] An electronic exchange capacity acquisition module, specifically including: a pretreatment filtration tank 1, an electrolyte storage tank 2, an electrochemical test tank 3, an automatic sampling system switch 4, an electrochemical signal collector 5, and a current integration module 6; a seed germination index prediction module, specifically including: an equation construction module 7 and a field maturity calculation module 8.

[0053] Figure 1 In the formula, i: current; A: current integration; GI: seed germination rate index; t: composting time.

[0054] The above test device can be operated and tested by the following method:

[0055] 1. Pretreatment filtration tank 1

[0056] Take a sample from the compost and mix it with water in a certain proportion (e.g., 5 g of sample and 10 mL of water), then add it to the filtration tank and stir vigorously for about 5 minutes. The pretreatment filtration tank 1 consists of a double structure. The outer layer is an impermeable container, and the inner layer is a filter mesh with pores. The filter mesh is 100 meshes. After stirring, most of the soluble organic matter is dissolved. Then, the filtrate flows into the electrochemical test tank 3 through the small tube in the outer container under the control of the switch 4, and the addition amount is 200 μL.

[0057] 2. Electrolyte storage tank 2

[0058] The electrolyte storage tank 2 is used to store electrolytes, such as PBS electrolyte. In this example, the concentration of the PBS electrolyte is 0.01 M, which belongs to a conventional chemical formula. Specifically: 8.0 g of NaCl, 0.2 g of KCl, 1.44 g of Na2HPO4, and 0.24 g of KH2PO4 are dissolved in 800 mL of distilled water, and the solution is adjusted to 7.4 with HCl, and finally made up to 1 L with distilled water. Under the control of the switch 4, the electrolyte in the electrolyte storage tank 2 flows into the electrochemical test tank 3, and the addition amount is 10 - 20 mL.

[0059] 3. Electrochemical test tank 3

[0060] 4. Automatic sampling system switch 4

[0061] 5. Electrochemical signal collector 5

[0062] The electrochemical test tank 3 adopts a three - electrode system to measure the current - time relationship diagram, and the set potential of the working electrode is 0.5 V. By controlling the automatic sampling system switch 4, first add the PBS electrolyte to the electrochemical test tank 3, and then instantaneously add the filtrate of the compost sample, and record the current - time curve through the electrochemical signal collector 5.

[0063] 6. Current integration module 6

[0064] The current integration module 6 uses the collected current as the data source, selects the integration region according to the data characteristics, integrates the collected current, and calculates the average value.

[0065] 7. Equation construction module 7

[0066] Using the same compost raw materials and the same operating parameters, historical data is collected. It mainly includes: the relationship between the seed germination rate index (GI) and the composting time (t), and the relationship between the current integration (A) and the composting time (t); based on these two relationships, the parameter t is eliminated to obtain the relationship between GI and A.

[0067] 8. In - situ maturity calculation module 8

[0068] Select the corresponding equation according to the raw materials and their proportions. Substitute the measured current integral A into the known relationship between GI and A to calculate the GI value of the compost product, and use this to evaluate the degree of compost maturity. Use this as data and adopt a neural network model in machine learning to correct the equation.

[0069] Method Example 1

[0070] A method for testing the degree of compost maturity, which is carried out based on the testing device of Device Example 1. The specific steps are as follows:

[0071] S1. Obtain the electron exchange capacity of the compost sample. The specific steps are as follows:

[0072] Use the sludge from the urban treatment plant (with a moisture content of about 80%) as the main raw material for composting, and straw (with a moisture content of about 10%) as the auxiliary material. By weight, the mass ratio of sludge to straw is 7:3. After mixing the above raw materials evenly, adjust the moisture content to about 60%, and carry out static aerobic composting. Aerate in an intermittent manner, with an aeration rate of: 0.03 L / kg·min, aerate for 15 minutes, stop for 1 hour, and so on in cycles to obtain the compost sample.

[0073] Take a sample from the compost, mix it with water in a certain proportion (for example, 5 g of sample and 10 mL of water), and add it to the pretreatment filtration tank 1, and stir vigorously for about 5 minutes. The pretreatment filtration tank 1 consists of a double structure. The outer layer is an impermeable container, and the inner layer is a filter screen with pores. The filter screen is 100 mesh. After stirring, most of the soluble organic matter can be dissolved, and the filtrate can flow into the electrochemical test tank 3 through the small tube in the outer container under the control of the switch 4, and the addition amount is 200 μL.

[0074] Under the control of the switch 4, the PBS electrolyte in the electrolyte storage tank 2 can flow into the electrochemical test tank 3, and the addition amount is 10 - 20 mL. The concentration of the PBS electrolyte is 0.01 M, which belongs to a conventional chemical formula. Specifically: 8.0 g of NaCl, 0.2 g of KCl, 1.44 g of Na2HPO4, 0.24 g of KH2PO4 are dissolved in 800 mL of distilled water, adjust the solution to 7.4 with HCl, and finally make up the volume to 1 L with distilled water.

[0075] First, add the PBS electrolyte in the electrolyte storage tank 2 to the electrochemical test tank 3, and then instantaneously add the filtrate from the pretreatment filtration tank 1. Adopt a three-electrode system, set the potential of the working electrode to 0.5 V, and use the electrochemical signal collector 5 to collect the relationship curve of the current and time of the sample in the electrochemical test tank 3.

[0076] Input the data collected by the electrochemistry signal collector 5 into the current integration module 6, select the integration area, integrate the collected current, and calculate the average value to obtain the current integration A, which is the electron exchange ability of the compost sample.

[0077] S2. Test historical data. Import the historical data through the historical data import module 7 to obtain the seed germination index prediction model (GI~A equation). Substitute the current integration A measured in step S1 into the known model to calculate the GI value of the compost product, and use this to evaluate the degree of compost maturity. Use this as data and adopt the neural network model in machine learning to correct and improve the known model, and use this as the corrected GI~A equation for testing the compost maturity of the next batch.

[0078] The specific steps for testing historical data are as follows: Use the same compost raw materials to carry out orthogonal aerobic composting for 40 days, continuously sample every day, and take 15 samples every day. For each sample, measure the three-dimensional fluorescence spectrum, seed germination rate, FA value (fulvic acid content), HA value (humic acid content), and the electron-donating ability and electron-accepting ability of water-soluble organic matter (abbreviated as electron exchange ability, which is the average value of the maximum of the two, obtained by integrating the area of the measured current-time graph as in step S1). Use the three-dimensional fluorescence spectrum, FA, and HA indicators as aids to correct the seed germination rate indicator (adopt those with consistent correlation and discard those with inconsistent correlation), and determine the final seed germination rate parameter as historical data. Respectively use the electron exchange ability as the independent variable (the integration A of the current), the corrected seed germination rate (GI) as the response variable, and the composting time (t) as the independent variable to fit the relationship curve between the electron exchange ability and the composting time (A~t) and the relationship curve between the seed germination index and the composting time (GI~t), eliminate the time t parameter, and finally obtain the functional relationship between GI and A (GI~A equation).

[0079] In this example, the relationship curve between the electron exchange ability and the composting time and the relationship curve between the seed germination index and the composting time are as Figure 3 shown, where (A) is the relationship curve between the electron exchange ability and the composting time, (B) is the relationship curve between the seed germination index and the composting time, and the electron exchange ability is represented by the integrated area. From Figure 3 it can be obtained that the relationship between the composting time and the integrated area (the functional relationship is t = f(A)):

[0080] t = 1.64056×A 3 -7.89254×A 2 +19.68781×A - 3.01887 (R 2 = 0.95346) (1)

[0081] From Figure 3It can be obtained that the relationship between the seed germination rate and the composting time is as follows:

[0082] GI = -0.01593×t 3 +0.47257×t 2 +0.67690×t + 22.11857(R 2 = 0.98361) (2)

[0083] Substituting formula (1) into (2), the relationship between GI and the integral area can be obtained:

[0084] GI = -0.01593×f(A) 3 +0.47257×f(A) 2 +0.67690×f(A) + 22.11857 (3)

[0085] Therefore, according to the above formula, by substituting the current integral A measured in step S1 into formula (3), the GI value can be calculated, and this value reflects the degree of compost maturity.

[0086] The degree of compost maturity was tested on the 2nd, 5th, 10th, and 20th days of composting using the above method.

[0087] Method Example 2

[0088] A method for testing the degree of compost maturity, which is carried out based on the testing device of Device Example 1. The specific steps are different from those of Method Example 1 in that the composting method is different. In this example, the composting method is as follows: Using chicken manure (with a moisture content of about 60%) as the main composting material and rice husk (with a moisture content of about 10%) as the auxiliary material, with a weight ratio of 8:2. After mixing the above raw materials evenly, add water to adjust the moisture content to about 60%, and carry out static aerobic composting. Aeration is carried out in an intermittent manner, and the aeration volume is: 0.03 L / kg·min, aerate for 15 minutes, stop for 1 hour, and so on in a cycle;

[0089] In this example, the relationship curve between the electron exchange capacity and the composting time, and the relationship curve between the seed germination index and the composting time are as Figure 4 shown. Among them, (A) is the relationship curve between the electron exchange capacity and the composting time, (B) is the relationship curve between the seed germination index and the composting time, and the electron exchange capacity is expressed by the integral area. It can be obtained from the figure that the relationship between the composting time and the integral area (the functional relationship is t = f(A)):

[0090] t = -2.71302×A 2 +15.02000×A - 0.54508(R 2 = 0.97698) (4)

[0091] From Figure 4It can be obtained that the relationship between the seed germination rate and the composting time is as follows:

[0092] GI = -0.03867×t 3 +1.23143×t 2 -6.36190×t + 32.97143(R 2 = 0.97763) (5)

[0093] Substituting formula (4) into (5), the relationship between GI and the integral area can be obtained:

[0094] GI = -0.03867×f(A) 3 +1.23143×f(A) 2 –6.36190×f(A) + 32.97143 (6)

[0095] Therefore, according to the above formula, by substituting the current integral A measured in step S1 into formula (6), the GI value can be calculated, and this value reflects the degree of compost maturity.

[0096] The degree of compost maturity was tested using this device on the 2nd, 5th, 10th, and 20th days of composting.

[0097] Method Example 3

[0098] A method for testing the degree of compost maturity, which is carried out based on the testing device of Device Example 1. The specific steps are different from those of Method Example 1 in that the composting method is different. In this example, the composting method is as follows: Using the sludge from the urban treatment plant (with a moisture content of about 80%) and biogas residue (with a moisture content of about 90%) as the main composting materials, and straw (with a moisture content of about 10%) as the auxiliary material. By weight, the mass ratio of sludge, biogas residue, and straw is 5:3:4. After mixing the above raw materials evenly, the moisture content is adjusted to about 60%, and static aerobic composting is carried out. Aeration is carried out in an intermittent manner, and the aeration volume is: 0.03 L / kg·min, aeration for 15 minutes, stop for 1 hour, and so on in a cycle;

[0099] In this example, the relationship curve between the electron exchange capacity and the composting time, and the relationship curve between the seed germination index and the composting time are as Figure 5 shown. Among them, (A) is the relationship curve between the electron exchange capacity and the composting time, (B) is the relationship curve between the seed germination index and the composting time, and the electron exchange capacity is represented by the integral area. It can be obtained from the figure that the relationship between the composting time and the integral area (the functional relationship is t = f(A)):

[0100] t = –1.69409×A 2 +11.88149×A - 0.19308(R 2 = 0.94019) (7)

[0101] FromFigure 5 It can be obtained that the relationship between the seed germination rate and the composting time is as follows:

[0102] GI = 0.02707×t 3 –0.63257×t 2 +6.57476×t + 11.91143 (R 2 = 0.95281) (8)

[0103] Substituting formula (4) into (5), the relationship between GI and the integral area can be obtained:

[0104] GI = 0.02707×f(A) 3 -0.63257×f(A) 2 +6.57476×f(A) + 11.91143 (9)

[0105] Therefore, according to the above formula, by substituting the current integral A measured in step S1 into formula (9), the GI value can be calculated, and this value reflects the degree of maturity of the compost.

[0106] On the 2nd, 5th, 10th, and 20th days of composting, the degree of maturity of the compost was tested using this device.

[0107] Method Comparative Example 1

[0108] A method for testing the degree of maturity of compost, the specific steps are as follows:

[0109] Composting was carried out in the same way as in Method Example 1;

[0110] The conventional seed germination rate method was used for determination to determine the degree of maturity of the compost.

[0111] Method Comparative Example 2

[0112] A method for testing the degree of maturity of compost, the specific steps are as follows:

[0113] Composting was carried out in the same way as in Method Example 2;

[0114] The conventional seed germination rate method was used for determination to determine the degree of maturity of the compost.

[0115] Method Comparative Example 3

[0116] A method for testing the degree of maturity of compost, the specific steps are as follows:

[0117] Composting was carried out in the same way as in Method Example 3;

[0118] The conventional seed germination rate method was used for determination to determine the degree of maturity of the compost.

[0119] The compost maturity test results in Method Examples 1 to 3 and Method Comparative Examples 1 to 3 are shown in Table 1 below.

[0120] Table 1 Compost maturity test results in Method Examples 1 to 3 and Method Comparative Examples 1 to 3

[0121]

[0122]

[0123] It can be seen from the results of the above implementation cases that the device designed in the present invention is used for the determination of compost maturity, and there is little difference from the traditional evaluation method by the seed germination rate. The error is within an acceptable range. The method of the present invention can be measured in real time on site, and the total test time is within 1 hour. However, the test method of the traditional seed germination rate takes at least one week. Moreover, since there are many parameters involved in seed germination, for example, high-quality seeds have a high germination rate, while poor-quality seeds may not germinate, directly leading to misjudgment of the test results. This method not only improves the processing efficiency and reduces the labor cost, but also reduces the energy consumption and improves the accuracy.

[0124] In summary, the present invention selects the historical electron exchange capacity of the compost sample and its corresponding composting time, as well as the historical seed germination index and its corresponding composting time as sample data. Both the historical electron exchange capacity and the historical seed germination index of the compost sample have a positive correlation with the composting time. Using the composting time as an intermediate variable, a seed germination index prediction model is established. In the actual test process, only by measuring the electron exchange capacity of the sample, the seed germination index can be calculated, so as to perform on-site and rapid determination of the composting process and accurately evaluate the compost maturity.

Claims

1. A method for testing the maturity of compost, characterized in that: include: obtaining the electron exchange capacity of the first compost sample; The electron exchange capacity is input into a seed germination index prediction model to obtain a seed germination index output by the seed germination index prediction model, and the compost maturity is evaluated based on the seed germination index; the seed germination index prediction model is trained based on sample data, and the sample data includes the historical electron exchange capacity of the second compost sample and its corresponding composting time, as well as the historical seed germination index of the second compost sample and its corresponding composting time.

2. The method for testing the maturity of compost according to claim 1, characterized in that: The historical seed germination index of the second compost sample is selected from the seed germination index having consistent correlation with the calibration index of the second compost sample; the calibration index of the second compost sample comprises a physical index, a chemical index or a combination thereof of the second compost sample.

3. The method for testing the maturity of compost according to claim 2, characterized in that: The physical indicator includes at least one of temperature, color or smell; And / or, the chemical indicators include at least one of carbon-nitrogen ratio, organic matter content, humus content, fluorescence spectrum or infrared spectrum.

4. The method for testing the maturity of compost according to claim 1, characterized in that: The obtaining of the electron exchange capacity of the first compost sample comprises: obtaining a curve of the relationship between current and time of the first compost sample, and performing area integration on the curve of the relationship between current and time of the first compost sample to obtain the electron exchange capacity of the first compost sample; Obtaining the historical electron exchange capacity of the second compost sample includes: obtaining a current-time relationship curve of the second compost sample, performing area integration on the current-time relationship curve of the second compost sample, and obtaining the historical electron exchange capacity of the second compost sample.

5. The method for testing the maturity of compost according to claim 4, characterized in that: The step of obtaining the relationship curve between the current and time of the first compost sample comprises: mixing the first compost sample, an electrolyte and a solvent, passing a first current, and measuring the relationship curve between the current and time of the first compost sample; The obtaining of the current-time relationship curve of the second compost sample comprises: mixing the second compost sample, electrolyte and solvent, passing a second current, and measuring the current-time relationship curve of the second compost sample.

6. The method for testing the maturity of compost according to claim 5, characterized in that: The potential used for passing the first current is 0.3-0.8V; And / or, the potential used for passing the second current is 0.3-0.8V.

7. The method for testing the maturity of compost according to claim 1, characterized in that: The first compost sample and the second compost sample each independently include at least one of the following raw materials: sludge, feces, and biogas residue.

8. The method for testing the maturity of compost according to claim 1, characterized in that: The equation function relationship of the seed germination index prediction model is as follows: GI=f(A) (1) A=f(t) (2) Among them, GI is the seed germination index, A is the electron exchange capacity, and t is the composting time.

9. A compost maturity testing device, characterized in that: include: An electron exchange capacity acquisition module, used to acquire the electron exchange capacity of the first compost sample; A seed germination index prediction module is used to input the electron exchange capacity into a seed germination index prediction model to obtain a seed germination index output by the seed germination index prediction model, and evaluate the compost maturity based on the seed germination index; the seed germination index prediction model is trained based on sample data, and the sample data includes a historical electron exchange capacity of a second compost sample and a corresponding composting time, as well as a historical seed germination index of the second compost sample and a corresponding composting time.

10. An electronic device, characterized in that: It comprises a processor and a memory storing computer program instructions; when the processor executes the computer program instructions, the method for testing the maturity of compost as claimed in any one of claims 1 to 8 is implemented.

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