A method for predicting bioavailable plastics based on biocaliber

Abstract

This invention belongs to the field of environmental pollutant ecological risk assessment technology. It discloses a method for predicting bioavailable plastics based on biocalibration, comprising the following steps: acquiring measured microplastic data for a target watershed, calibrating using a correction factor CF, and predicting bioavailable plastics based on biocalibration. x i To calculate the amount of microplastics that a specific organism can ingest, the total volume of microplastics ingested by the organism is calculated based on the unit particle volume that can be ingested. V per ,according to V per The availability of microplastics is calculated. The method of this invention is accurate, operable, and universal, establishing a unified data calibration process and biological caliber classification standard, enabling comparative evaluation across different watersheds and biological groups.

Description

Technical Field

[0001] This invention relates to the field of environmental pollutant ecological risk assessment technology, and in particular to a method for predicting the amount of bioavailable plastics based on biological caliber, applicable to microplastic risk assessment in aquatic ecosystems such as freshwater surface water, lakes, and rivers. Background Technology

[0002] As an emerging environmental pollutant, microplastics have become a research hotspot in the global environmental field for ecological risk assessment. Traditional microplastic risk assessment methods mainly rely on plastic abundance (the number of particles per unit volume) as the core indicator, directly comparing the measured environmental concentration with the threshold effect concentration to determine the risk level. However, this method has significant drawbacks: it ignores the matching between plastic size and the mouth size of organisms—small-mouthed organisms cannot ingest plastic particles larger than their own mouth size, and relying solely on abundance calculations can lead to overestimation or underestimation of risk; furthermore, the ecological effects of plastics are not only related to quantity but also to volume, and the same amount of large-sized plastics has a more significant food dilution effect on organisms.

[0003] Existing research has confirmed that the ecological effects of microplastics are closely related to their volumetric concentration, and that the bioavailability of microplastics of different sizes varies significantly. However, the lack of a unified calculation method that combines biological aperture, microplastic size distribution, and volumetric concentration leads to significant biases in risk assessment results, making it difficult to accurately reflect the ingestion exposure levels of organisms in the real environment. Therefore, there is an urgent need to develop a method for calculating ingestible plastics that considers the selectivity of biological ingestion to improve the accuracy of microplastic risk assessment. Summary of the Invention

[0004] The purpose of this invention is to address the technical deficiencies in the prior art by providing a method for predicting the amount of bioavailable plastics based on biocaliber.

[0005] The technical solution adopted to achieve the purpose of this invention is: A method for predicting bioavailable plastics based on biocaliber includes the following steps: Step 1: Obtain measured microplastic data for the target watershed, including microplastic abundance. C Size distribution range and the proportion of each size interval; Step 2, using the correction factor CF to analyze the microplastic abundance C The microplastic abundance was obtained by calibrating the size distribution range. and the calibrated size distribution range; Step 3: Calculate the amount of microplastics that a specific organism can ingest in a random sample. : If the mouth diameter of a specific organism x iIf the value is equal to the critical point of the calibrated size distribution range, then: in, P (size, x i ( ) refers to sizes less than or equal to the diameter x i The percentage of microplastics; If the mouth diameter of a specific organism x i If the critical point size is greater than the calibrated size distribution range, then: in, P (size, p ( ) is for sizes less than or equal to p The percentage of microplastics, P (size, p~x i ) is the size in p and x i The proportion of microplastics between them p For the closest after calibration x i and less than x i The critical point of the size distribution range, IF is p~x i Correction factors for size ranges; Step 4, combined with the results obtained in Step 3 Calculate the total volume of microplastics ingested by organisms in a random sample. V per ; Step 5: Calculate the availability of microplastics. .

[0006] In the above technical solution, in step 2, the size distribution range is calibrated to 1~ M ,but ,in: x 1 , x 2 These represent the maximum and minimum values ​​of the plastic size range collected in step 1. This is the average power law exponent.

[0007] In the above technical solution, in step 2, .

[0008] In the above technical solution, in step 2, the calibrated size distribution critical point is equal to the uncalibrated size distribution critical point multiplied by CF.

[0009] In the above technical solution, in step 3, x m , x n To determine the maximum and minimum sizes of the microplastic particles after calibration. This is the average power law exponent.

[0010] In the above technical solutions, when the target watershed is a freshwater environment, .

[0011] In the above technical solution, in step 4, ,in It refers to the volume of a unit particle that can be ingested by organisms.

[0012] In the above technical solutions, , L The length of the microplastic particles. W The width of the microplastic particles. H The height of the microplastic particles, 1 < L <M,1<W< x i 1 <H< x i .

[0013] In the above technical solution, in step 4, after the microplastic particle volume is generated as a random sample using a Matlab program, the distribution is verified to be reasonable through a normal distribution test, and the volume of each microplastic particle in the random sample is calculated. , thus calculating V per Repeat the random sampling multiple times, taking multiple samples V per The average value is used as the total volume of microplastics ingested by organisms.

[0014] In the above technical solution, in step 5, ,in This represents the total volume of plastics in the watershed.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. Accuracy: For the first time, biological aperture is combined with plastic size distribution and volume concentration, which solves the limitations of traditional abundance assessment and reduces the risk assessment bias by more than 60% after correction; 2. Standardization: Establish a unified data calibration process and biological classification standards to achieve comparable evaluation of different watersheds and different biological groups; 3. Operability: The calculation is automated through the Matlab program. The results can be output by inputting the abundance, size distribution and bio-aperture of plastics, which is suitable for environmental monitoring and risk assessment practices. 4. Universality: Applicable to various aquatic ecosystems such as freshwater surface water, lakes, and rivers, and can be extended to marine ecosystems (adjust α value). Attached Figure Description

[0016] Figure 1 This is a flowchart of the method of the present invention.

[0017] Figure 2 This is a comparison chart of data from a large flea feeding experiment. Detailed Implementation

[0018] The present invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

[0019] Example 1 like Figure 1 As shown, a method for predicting bioavailable microplastics based on biocaliber includes the following steps: Step 1, Data Collection: Collect measured data on plastics in the watershed, including microplastic abundance. C (Unit: items / L or items / m) 3 ), size distribution range and the proportion of each size interval; Step 2, using the correction factor CF to analyze the microplastic abundance C The size distribution range is calibrated to 1~5000. , , The average power law exponent is taken as 2.64 (a common value for freshwater surface water). The calibrated size distribution range and the proportion of each size interval are as follows: 1~500μm accounts for 70%, 500~1000μm accounts for 20%, and 1000~5000μm accounts for 10%.

[0020] Abundance after calibration =100 items / L; Step 3, classify organisms by mouth size: <0.5mm (e.g., rotifers), 0.5~1mm (e.g., small crustaceans), 1~5mm (e.g., juvenile crucian carp).

[0021] If we calculate the amount of ingestible plastic for small crustaceans with a mouth diameter of 1000 μm, then x i =1000μm; Here P(size, x i )= P (size, 1000), which is the proportion of 1~1000μm, specifically the proportion of 1~500μm and 500~1000μm. P (size, 1000) = 70% + 20% = 90%, =100 items / L =90 items.

[0022] If we calculate the amount of plastic that can be ingested by juvenile crucian carp with a mouth diameter of 2000 μm, then x i =2000μm, p =1000μm; ,in, P (size, p )= P (size, 1000) = 70% + 20% = 90%; P (size, p~x i This represents the percentage of the 1000~2000μm range; Here , , x i =2000μm, The value is 2.64 (a common value for freshwater surface water).

[0023] Step 4, Volume Calculation: The length range of microplastics ingested by an aquatic organism is set to the full-size range, while the width and height are set to be smaller than the organism's mouth diameter. The formula for calculating the ellipsoidal volume V is: 1< L <M,1<W< x i 1 <H< x i 。

[0024] After generating random samples of microplastic particle volumes using the Matlab program, the distribution was verified for reasonableness using a normal distribution test, and the volume of each microplastic particle in the random sample was calculated. ; The total volume of microplastics that can be ingested by an organism is: .

[0025] Repeat this process ten times to obtain ten samples.V per The average value is used as the total volume of microplastics that can be ingested by an organism, which can reduce the error.

[0026] Step 5, Bioavailability of Microplastics: ,in This represents the total volume of plastics in the watershed.

[0027] Example 2 This embodiment verifies the accuracy of Embodiment 1. (1) Experimental design: 50 large fleas (mouth diameter 98μm) were selected for each group and exposed to PLA microplastics (size 40~75μm, 75~150μm, 150~350μm) at a concentration of 0.5mg / L for 24 hours. Three parallel groups were set up. (2) Experimental results: After dissection, 2150 plastic particles were counted in the intestine, with a total volume of approximately 1.75 × 10⁻⁶. 8 μm³; the volume of food consumed was measured to be 14.58% of the total input. (3) Execute the algorithm of Example 1 using a Matlab program. 1. Input conditions: Total abundance: 4066 items / L (This is the experimental verification of the actual abundance, therefore...) C = =4066 items / L); Maximum ingestion diameter of large fleas: 98 μm; Size distribution percentage: 40-75 μm: 58.73%, 75-98 μm: 26.22%, 98-150 μm: 3.86%, 150-350 μm: 11.19%. Size distribution percentage does not require calibration here.

[0028] 2. Calculation process: Number of plastics that can be ingested , =4066 items / L P(size, x i = 58.73% + 26.22% = 84.95%. Output .

[0029] The volume of a single particle that can be ingested by large fleas: Since plastic particles were used as plastic microspheres in the experimental verification process, L=W=H=r (radius). The average radius of the plastic microspheres with a diameter of 40~75μm was taken as 57.5μm, and the average radius of the plastic microspheres with a diameter of 75~98μm was taken as 86.5μm. Output .

[0030] The total volume of microplastics that can be ingested by large fleas is: Output V per =1.88×10 7 μm 3 .

[0031] Bioavailability of microplastics: Since plastic particles were used as plastic microspheres in the experimental verification process, the volume of the spheres can be calculated using the formula for calculating the volume of the microspheres. Therefore, the output is... .

[0032] The calculated percentage of ingestible intake was 19.42%. This result is close to the 14.58% measured in experiments, further demonstrating that the calculated percentage has certain reference value.

[0033] The comparison chart of the results calculated manually (experimentally) and by the program is shown below. Figure 2 As shown.

[0034] The above description is only a preferred embodiment of the present invention. It should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for predicting the amount of microplastics that can be ingested by organisms based on bioaperture, characterized in that, Includes the following steps: Step 1: Obtain measured microplastic data for the target watershed, including microplastic abundance. C Size distribution range and the proportion of each size interval; Step 2, using the correction factor CF to analyze the microplastic abundance C The microplastic abundance was obtained by calibrating the size distribution range. and the range of calibrated size distribution; Step 3: Calculate the amount of microplastics that a specific organism can ingest in a random sample. : If the mouth diameter of a specific organism x i If the value is equal to the critical point of the calibrated size distribution range, then: in, P (size, x i ( ) refers to sizes less than or equal to the diameter x i The percentage of microplastics; If the mouth diameter of a specific organism x i If the critical point size is greater than the calibrated size distribution range, then: in, P (size, p ( ) is for sizes less than or equal to p The percentage of microplastics, P (size, p~x i ) is the size in p and x i The proportion of microplastics between them p For the closest after calibration x i and less than x i The critical point of the size distribution range, IF is p~x i Correction factors for size ranges; Step 4, combined with the results obtained in Step 3 Calculate the total volume of microplastics ingested by organisms in a random sample. V per ; Step 5: Calculate the availability of microplastics. .

2. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 1, characterized in that, In step 2, the size distribution range is calibrated to 1~ M ,but ,in: x 1 , x 2 These represent the maximum and minimum values ​​of the plastic size range collected in step 1. This is the average power law exponent.

3. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 1, characterized in that, In step 2, .

4. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 1, characterized in that, In step 2, the calibrated size distribution critical point is equal to the uncalibrated size distribution critical point multiplied by CF.

5. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 1, characterized in that, In step 3 x m , x n To determine the maximum and minimum sizes of the microplastic particles after calibration. This is the average power law exponent.

6. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 5, characterized in that, When the target watershed is a freshwater environment .

7. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 1, characterized in that, In step 4 ,in It refers to the volume of a unit particle that can be ingested by organisms.

8. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 7, characterized in that, , L The length of the microplastic particles. W The width of the microplastic particles. H The height of the microplastic particles, 1 < L <M,1<W< x i 1 <H< x i .

9. The method for predicting bioavailable microplastics based on bioaperture diameter as described in claim 7, characterized in that, In step 4, after generating random samples of microplastic particle volumes using a Matlab program, the distribution is verified for reasonableness using a normal distribution test, and the volume of each microplastic particle in the random sample is calculated. , thus calculating V per Repeat the random sampling multiple times, taking multiple samples V per The average value is used as the total volume of microplastics ingested by organisms.

10. The method for predicting bioavailable microplastics based on bioaperture as described in claim 1, characterized in that, In step 5 ,in This represents the total volume of plastics in the watershed.

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