A method for determining the ecotoxicity of black matter in soil

Abstract

The present invention relates to a method for determining the ecotoxicity of black matter in soil, which comprises the following steps: S1. medium preparation: soil containing black matter is used as a test medium, and is mixed with peat in a ratio to form a test specimen, which is placed in a plurality of specimen bottles for standby use; S2. biological culture test: a plurality of specimen bottles are divided into two groups, the first group is subjected to an earthworm toxicity test, and the second group is subjected to a plant germination rate test; S3. observation and statistics of test results: for the earthworm toxicity test of the first group, the average body weight Z7 of earthworms at 7 days and the average number of surviving earthworms Y at 14 days are counted; for the plant germination rate test of the second group, the average number of germinated seeds D is counted; S4. the ecotoxicity level is determined by calculating the test data. The advantage is that the present invention effectively combines the earthworm animal test and the plant germination rate culture test, and can quickly, accurately and comprehensively determine the ecotoxicity of soil containing black matter.

Description

Technical Field

[0001] The invention relates to the field of soil pollution detection, and in particular to a method for determining the ecotoxicity of black matter in soil. Background Art

[0002] Soil plays an important role in natural systems and human society. Soil has a certain buffering balance capacity against adverse effects caused by pollutants. When the adverse effects exceed its buffering balance capacity, the soil quality will decline, and its function will be affected or even destroyed. Research on the ecotoxicity of certain substances in the soil is an important basis for the management and control of soil pollution. Only by determining the prevention and control technology of pollution based on the real ecotoxicity effect can the restoration, management and protection of contaminated soil be carried out in an optimized mode.

[0003] For the determination of ecotoxicity of certain substances in soil, chemical analysis methods are usually based on the analysis of the total content of a substance. Considering the biological effectiveness, the influence of the matrix, the complexity and diversity of pollution, the limitations of the analysis method, etc., relying solely on chemical analysis methods is usually not able to accurately determine the ecotoxicity of the substance. Soil ecotoxicity test methods should more comprehensively reflect the degree of pollution and impact of a substance in the soil. Soil ecotoxicity test methods can be divided into in vivo tests and in vitro tests according to whether living organisms or microorganisms, in vitro tissues and cells are used in the test; according to the biological classification of the test organisms, they can be divided into microbial, plant and animal toxicity tests; according to the level classification of its test endpoints, they can be divided into sub-individuals (molecules, organelles, cells, tissues and organs, etc.) and individuals.

[0004] Traditional soil pollution ecotoxicity tests are all acute toxicity tests for single species, which makes it difficult to truly reveal the true ecotoxicity effects of soil pollution. Although evaluation factors and species sensitivity curves can be used to achieve extrapolation from species to ecosystem levels, the extrapolation method has high requirements on database quality on the one hand and great uncertainty on the other hand, and still has certain limitations in practical applications. Therefore, it is necessary to provide an effective method for relatively comprehensive ecotoxicity determination of soils containing black substances. Summary of the invention

[0005] The invention provides a method for determining the ecotoxicity of black matter in soil, aiming to overcome the deficiency in the prior art that there is a lack of effective ecotoxicity assessment for black matter in soil.

[0006] The technical solution of the present invention to solve the above technical problem is as follows: A method for determining the ecotoxicity of black matter in soil, comprising the following steps:

[0007] S1. Medium preparation: Soil containing black matter is used as the test medium, and is mixed with peat in a mass ratio of 13-15:1 to form test specimens. The test specimens are placed in multiple specimen bottles, and the moisture content and pH value of the test specimens are adjusted with deionized water and pH regulator for later use;

[0008] S2. Biological culture test: multiple specimen bottles were divided into two groups, the first group was subjected to earthworm toxicity test, and the second group was subjected to plant germination rate test. Ten adult earthworms that met the test standards were put into each specimen bottle of the first group, and 15 green vegetable seeds were put into each specimen bottle of the second group and properly buried. The mouth of each specimen bottle was sealed with plastic wrap and some air holes were reserved, and then placed in an artificial climate box for culture. At the same time, uncontaminated artificial soil was put into several specimen bottles and green vegetable seeds were put in the same way as blank controls for the plant germination rate test.

[0009] S3. Observation and statistics of test results: For the earthworm toxicity test of the first group, several specimen bottles were randomly selected on the 7th and 14th days, the test specimens in the specimen bottles were poured out, and the average body weight Z7 of the earthworms on the 7th day was measured, and the difference between the average body weight Z0 of the earthworms and the initial average body weight Z0 was counted. At the same time, the average number of surviving earthworms Y on the 14th day was counted; for the plant germination rate test of the second group, when the seed root length of the blank control group reached 20mm, the test was terminated, and several specimen bottles were randomly selected to count the average number of germinated seeds D;

[0010] S4. Calculate the test data to determine the ecotoxicity level: calculate the earthworm mortality rate M, physical inhibition rate N and seed non-germination rate P, and calculate the ecotoxicity index X according to X = 0.3 × M + 0.3 × N + 0.4 × P.

[0011] in

[0012] When the value of X is in the range of 0-0.1, 0.11-0.30, 0.31-0.60 and 0.61-1.0, it represents the ecotoxicity levels of no ecotoxicity, mild ecotoxicity, moderate ecotoxicity and severe ecotoxicity, respectively.

[0013] Based on the above technical solution, the present invention can also be improved as follows.

[0014] Specifically, the mass of the test specimen placed in each specimen bottle in S1 is between 750-1000 g.

[0015] Specifically, after the test specimen is placed in the specimen bottle and the moisture content and pH are adjusted in S1, the moisture content of the test specimen is 50%, and the pH is between 6.8-7.2.

[0016] Specifically, the pH regulator in S1 is calcium carbonate.

[0017] Specifically, the inner diameter of the mouth of the specimen bottle in S1 is 5-8 cm.

[0018] Specifically, the number of sample bottles in each group in S2 is at least 3, and the adult earthworms that meet the test standards are those with annular bands and individual weights between 300-600 mg.

[0019] Specifically, the vent holes reserved in S2 are formed by puncturing the plastic wrap with a disposable needle multiple times.

[0020] Specifically, the temperature in the artificial climate box in S2 is controlled at 20-25°C, the humidity is controlled at 70-80%, and the light-dark ratio is 12-15:10.

[0021] Compared with the prior art, the present invention has the following beneficial effects:

[0022] The present invention provides a method for determining the ecotoxicity of black matter in soil. The method effectively combines earthworm animal tests and plant germination rate culture tests to determine the acute toxicity of soil containing black matter to earthworms and the inhibition of plant growth, thereby being able to quickly, accurately and relatively more comprehensively determine the ecotoxicity of soil containing black matter, thereby providing certain reference and guidance for planning and use decisions of land containing black matter in specific areas. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 The present invention provides a flow chart of a method for determining the ecotoxicity of black matter in soil. DETAILED DESCRIPTION

[0024] The principles and features of the present invention are described below in conjunction with the accompanying drawings and specific embodiments. The examples given are only used to explain the present invention and are not used to limit the scope of the present invention.

[0025] It should be noted that there are many possible black substances in the soil, including but not limited to black humus, animal and plant residues, minerals (such as iron oxide or ferrous oxide), carbon black, petroleum, coal tar, heavy metal salts, coal ash, slag, etc. Some of these black substances in the soil are non-toxic and beneficial to plant growth, soil microorganisms and soil animals (earthworms, ants, crickets, etc.), but others are obviously toxic and affect the normal growth of plants and animals. Therefore, the determination of the ecotoxicity of black substances in the soil can understand the pollution of soil in a specific area, so as to provide reference and guidance for land use decisions in a specific area.

[0026] like Figure 1 As shown, the present invention provides a method for determining the ecotoxicity of black matter in soil, which comprises the following steps:

[0027] S1. Medium preparation: Soil containing black matter is used as the test medium, and is mixed with peat at a mass ratio of 15:1 to form test specimens. The test specimens are placed in multiple specimen bottles, and the moisture content of the test specimens is adjusted to 50% and the pH value is 6.8 with deionized water and a pH regulator (preferably calcium carbonate). The diameter of the bottle mouth is about 5-8 cm. The mass of the test specimen in each specimen bottle is 1000 g, of which the mass of the soil containing black matter is 937.5 g and the mass of peat is 62.5 g, and they are set aside;

[0028] S2. Biological culture test: multiple specimen bottles are divided into two groups, the first group is subjected to earthworm toxicity test, and the second group is subjected to plant germination rate test. In each specimen bottle of the first group, 10 adult earthworms that meet the test standards are put in (adult earthworms with annular bands and weighing between 300-600 mg are selected for the test, and they need to be weighed before being put in, and the initial average body weight Z0 of the earthworms in each specimen bottle is obtained and counted), and in each specimen bottle of the second group, 15 green vegetable seeds are put in and appropriately buried (the burying depth is about 0.5-2 cm), and the mouth of each specimen bottle is sealed with plastic wrap and some air holes are reserved (some small holes are poked on the film with a disposable needle), and then placed in an artificial climate box for cultivation, the temperature in the artificial climate box is controlled at 20-25℃, the humidity is controlled at 70-80%, and the light-dark ratio is 12-15:10; at the same time, unpolluted artificial soil is put into several specimen bottles and green vegetable seeds are put in the same way as a blank control for the plant germination rate test;

[0029] S3. Observation and statistics of test results: For the earthworm toxicity test of the first group, several specimen bottles were randomly selected on the 7th and 14th days, the test specimens in the specimen bottles were poured out, and the average body weight Z7 of the earthworms on the 7th day was measured, and the difference between the average body weight Z0 of the earthworms and the initial average body weight Z0 was counted. At the same time, the average number of surviving earthworms Y on the 14th day was counted; for the plant germination rate test of the second group, when the seed root length of the blank control group reached 20mm, the test was terminated, and several specimen bottles were randomly selected to count the average number of germinated seeds D;

[0030] S4. Calculate the test data to determine the ecotoxicity level: calculate the earthworm mortality rate M, physical inhibition rate N and seed non-germination rate P, and calculate the ecotoxicity index X according to X = 0.3 × M + 0.3 × N + 0.4 × P.

[0031] in

[0032] When the value of X is in the range of 0-0.1, 0.11-0.30, 0.31-0.60 and 0.61-1.0, it represents the ecotoxicity levels of no ecotoxicity, mild ecotoxicity, moderate ecotoxicity and severe ecotoxicity, as shown in the following table:

[0033] Ecotoxicity Index 0～0.1 0.11～0.30 0.31～0.60 0.61～1.0 Ecotoxicity level No ecotoxicity Mild ecotoxicity Moderate ecotoxicity Severe ecotoxicity

[0034] According to the present invention, a method for determining the ecotoxicity of black matter in soil is provided. Some soils containing a specific amount of black matter are tested as test samples. The results are shown in the following table:

[0035]

[0036] It can be seen from the data in the above table that the method for determining the ecotoxicity of black matter in soil provided by the present invention can determine the ecotoxicity of black matter in soil more effectively, comprehensively and accurately.

[0037] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for determining the ecotoxicity of black matter in soil, characterized in that: The steps include: S1. Medium preparation: Soil containing black matter is used as the test medium, and is mixed with peat in a mass ratio of 13-15:1 to form test specimens. The test specimens are placed in multiple specimen bottles, and the moisture content and pH value of the test specimens are adjusted with deionized water and pH regulator for later use; S2. Biological culture test: multiple specimen bottles were divided into two groups, the first group was subjected to earthworm toxicity test, and the second group was subjected to plant germination rate test. Ten adult earthworms that met the test standards were put into each specimen bottle of the first group, and 15 green vegetable seeds were put into each specimen bottle of the second group and properly buried. The mouth of each specimen bottle was sealed with plastic wrap and some air holes were reserved, and then placed in an artificial climate box for culture. At the same time, uncontaminated artificial soil was put into several specimen bottles and green vegetable seeds were put in the same way as blank controls for the plant germination rate test. S3. Observation and statistics of test results: For the earthworm toxicity test of the first group, several specimen bottles were randomly selected on the 7th and 14th days, the test specimens in the specimen bottles were poured out, and the average body weight Z7 of the earthworms on the 7th day was measured, and the difference between the average body weight Z0 of the earthworms and the initial average body weight Z0 was counted. At the same time, the average number of surviving earthworms Y on the 14th day was counted; for the plant germination rate test of the second group, when the seed root length of the blank control group reached 20mm, the test was terminated, and several specimen bottles were randomly selected to count the average number of germinated seeds D; S4. Calculate the test data to determine the ecotoxicity level: calculate the earthworm mortality rate M, physical inhibition rate N and seed non-germination rate P, and calculate the ecotoxicity index X according to X = 0.3 × M + 0.3 × N + 0.4 × P, where When the value of X is in the range of 0-0.1, 0.11-0.30, 0.31-0.60 and 0.61-1.0, it represents the ecotoxicity levels of no ecotoxicity, mild ecotoxicity, moderate ecotoxicity and severe ecotoxicity, respectively.

2. The method for determining the ecotoxicity of black matter in soil according to claim 1, characterized in that: The mass of the test specimen placed in each specimen bottle in S1 is between 750-1000g.

3. The method for determining the ecotoxicity of black matter in soil according to claim 1, characterized in that: After the test specimen in S1 is placed in the specimen bottle and the moisture content and pH are adjusted, the moisture content of the test specimen is 50% and the pH is between 6.8-7.

2.

4. The method for determining the ecotoxicity of black matter in soil according to claim 2, characterized in that: The pH regulator in S1 is calcium carbonate.

5. The method for determining the ecotoxicity of black matter in soil according to claim 1, characterized in that: The inner diameter of the mouth of the specimen bottle in S1 is 5-8 cm.

6. The method for determining the ecotoxicity of black matter in soil according to claim 1, characterized in that: The number of specimen bottles in each group of S2 is at least 3, and the adult earthworms that meet the test standards are those with annular bands and individual weights between 300-600 mg.

7. The method for determining the ecotoxicity of black matter in soil according to claim 1, characterized in that: The reserved vent holes in S2 are formed by puncturing the plastic wrap with a disposable needle multiple times.

8. The method for determining the ecotoxicity of black matter in soil according to any one of claims 1 to 7, characterized in that: The temperature in the artificial climate box in S2 was controlled at 20-25°C, the humidity was controlled at 70-80%, and the light-dark ratio was 12-15:10.

Images