阅读说明：本技术 一种环境污染物生态毒性效应半效浓度测算方法 (Method for measuring and calculating semi-effective concentration of environmental pollutant ecotoxicity effect ) 是由 王长友 于 2019-10-08 设计创作，主要内容包括：本发明公开了一种环境污染物生态毒性效应半效浓度测算方法,基于单物种的毒性效应实验结果,利用种群间的生态关系构建群落模型,将处于不同营养级的、种群水平上的、多个反应终点结合起来,以一定污染物浓度下简化浮游群落稳态生物量数组(P*,Q*,R*)偏离原稳态生物量数组(P<Sub>0</Sub>,Q<Sub>0</Sub>,R<Sub>0</Sub>)的程度作为判据,计算污染物生态毒性效应半效浓度。本发明考虑了污染物毒性效应的生态相关性,从而提高了测算的准确性、科学性；本发明还能够充分利用现有的大量单物种毒性效应实验数据,节约费用。(The invention discloses a method for measuring and calculating the half-effect concentration of the ecological toxic effect of environmental pollutants, which is based on the experimental result of the toxic effect of a single species, utilizes the ecological relationship among populations to construct a community model, combines a plurality of reaction end points on the population level and at different nutrition levels, and simplifies the deviation of a floating community steady-state biomass array (P, Q, R) from an original steady-state biomass array (P, Q, R) under a certain pollutant concentration 0 ,Q 0 ,R 0 ) The degree of the pollutant is used as a criterion to calculate the ecological toxicity effect half-effect concentration of the pollutant. The invention considers the ecological relevance of the toxic effect of the pollutant, thereby improving the accuracy and the scientificity of the measurement and calculation; the invention can also make full use of the existing large number of sheetsSpecies toxicity effect experiment data and cost saving.)

1. A method for measuring and calculating the half-effect concentration of the ecotoxicity effect of environmental pollutants is characterized by comprising the following steps:

step 1), performing a toxicity effect experiment of a single-algae culture system, and calculating the intrinsic growth rate and the environmental tolerance of microalgae populations under different pollutant concentrations;

step 2), carrying out a toxicity effect experiment of the zooplankton population, calculating the survival rate, the reproduction rate, the intrinsic growth rate and the generation time of the zooplankton under different pollutant concentrations, and the female oviposit rate and the population proliferation rate of the zooplankton population under different pollutant concentrations, and analyzing the toxicity effect of the pollutants on the zooplankton population by taking the female oviposit rate and the population proliferation rate as reaction endpoints;

step 3), calculating EC at each reaction end point based on the toxicity effect experiment result of plankton population₁₀、EC₅₀、EC₉₀And 95% confidence interval thereof, analyzing the sensitivity, reliability and stability of the ecotoxicity effect at different reaction end points, and determining the half-Effect Concentration (EC) of the ecotoxicity effect₅₀Constructing a population toxicity effect model at the reaction end point of (1);

step 4), performing a double-algae competition experiment, and calculating competition inhibition parameters of the microalgae;

step 5), carrying out a zooplankton feeding experiment, and calculating the water drainage rate and the feeding rate of the zooplankton to the microalgae;

step 6), carrying out a feeding behavior experiment of the zooplankton, and calculating a feeding selectivity coefficient of the zooplankton for the microalgae;

step 7), constructing a simplified floating community model with competition-feeding effect;

and 8), constructing a plankton community-toxicity effect coupling model, calculating a steady-state biomass array (P, Q, R), and calculating the half-effect concentration by taking the steady-state biomass array as a reaction endpoint.

2. The method for measuring and calculating the half-effect concentration of the ecotoxic effect of environmental pollutants according to claim 1, wherein the specific steps of the step 1) are as follows:

step 1.1), filtering seawater to add a proper amount of nutrient salt as a culture solution by taking microalgae bred in a laboratory as an object, placing the culture solution in a culture bottle, and culturing in an illumination incubator according to preset culture temperature, salinity, illumination intensity, micro-structure initial density and photoperiod;

step 1.2), setting 3 parallel samples in each group according to a preset pollutant concentration interval; performing species identification and counting under a microscope every day, and finishing the experiment when the population of the experimental object shows decay;

and 1.3) utilizing Logistic growth model fitting to obtain the intrinsic growth rate and the environmental tolerance of the microalgae, and analyzing the toxic effect of the pollutants on the microalgae population.

3. The method for measuring and calculating the half-effect concentration of the ecotoxic effect of environmental pollutants according to claim 1, wherein the specific steps of the step 2) are as follows:

step 2.1), zooplankton monomer culture:

step 2.1.1), selecting healthy and active mature females of zooplankton, and placing 1 in each spawning bottle containing culture solution;

step 2.1.2), setting 10 parallel samples in each group according to the preset concentration interval of pollutants, and culturing at constant temperature according to the preset culture temperature; checking and counting the number of spawned eggs, the number of hatched larvae and the survival condition of a parent every day, removing the larvae, simultaneously changing culture solution water according to the proportion of about 1/2, and adding bait algae; the experiment was carried out until the female died;

step 2.1.3), calculating survival rate, reproduction rate, intrinsic growth rate and generation time of zooplankton, and analyzing toxic effect of pollutants on zooplankton population;

step 2.2), carrying out accumulative culture of zooplankton population:

step 2.2.1), quantitatively moving a plurality of lively and strong zooplankton which are pre-cultured under the same conditions to be placed in a beaker filled with culture solution;

step 2.2.2), setting 3 parallel samples in each group according to the preset concentration interval of pollutants, culturing at constant temperature until the population growth reaches a peak and begins to decline; feeding bait once every 24h during the experiment; counting the total individual number, the egg-carrying individual number and the number of fallen summer eggs of the zooplankton every day;

and 2.2.3) calculating the egg laying rate and the population proliferation rate of female zooplankton, and analyzing the toxic effect of pollutants on zooplankton populations.

4. The method for measuring and calculating the half-effect concentration of the ecotoxic effect of environmental pollutants according to claim 1, wherein the specific steps of the step 4) are as follows:

step 4.1), mixing the experimental microalgae two by two, and setting the initial inoculation biomass of the microalgae according to the density of algae cells in a culture solution and the biological volume of a single algae cell so that the biomass ratio of the co-cultured microalgae is 1: 1;

and 4.2) fitting by using a Lotka-Volterra competition model to obtain a competition inhibition parameter.

5. The method for measuring and calculating the half-effect concentration of the ecotoxic effect of environmental pollutants according to claim 1, wherein the specific steps of the step 5) are as follows:

step 5.1), domesticating and culturing the pre-cultured zooplankton in corresponding microalgae to be ingested for 3-5d, and starving for 24 h;

step 5.2), carrying out experiments in beakers, wherein the microalgae density is a preset optimal feeding density threshold, a plurality of zooplanktons are added into each beaker, each experimental group is provided with 3 parallel samples, and a control group without the zooplanktons is additionally arranged; covering the experimental beaker with black cloth and culturing for 24h under a dark condition;

step 5.3), counting after 24 hours by adopting a bait concentration difference method, fixing the algae liquid by using the Ruoge liquid, counting by using a blood ball counting plate under a microscope and calculating the cell density of the algae;

and 5.4) calculating the water drainage rate and the food intake rate of the zooplankton to the microalgae.

6. The method for measuring and calculating the half-effect concentration of the ecotoxic effect of environmental pollutants according to claim 1, wherein the specific steps of the step 6) are as follows:

step 6.1), mixing the microalgae two by two, feeding the selected zooplankton, determining the mixing ratio according to the biological volume of a single algae cell to ensure that the biomass ratio of the two microalgae is 1:1, adding a plurality of zooplanktons into each beaker, arranging 3 parallel samples in each experimental group, and arranging a control group without the zooplanktons; covering the experimental beaker with black cloth and culturing for 24h under a dark condition;

step 6.2), calculating the ingestion rate of the zooplankton to the microalgae by adopting a bait concentration difference method;

and 6.3) determining the feeding selectivity coefficient according to the feeding degree of the zooplankton to different microalgae.

7. The method for measuring and calculating the half-effect concentration of the ecotoxic effect of environmental pollutants according to claim 1, wherein the specific steps of the step 8) are as follows:

step 8.1), based on the analysis result of the reaction end point, embedding a population toxicity effect model into a plankton community model by taking the population toxicity effect reaction end point and the toxicity effect semi-effective concentration which have obvious ecological significance as model parameters, and constructing a plankton community-toxicity effect coupling model, so that a plurality of reaction end points on different nutrition levels and population levels are combined to calculate the biological community toxicity effect;

and 8.2) calculating a steady-state biomass array (P, Q, R) of the plankton community by using a coupling model and a Bootstrap sampling mathematical statistic method, measuring and calculating the semi-effective concentration of the ecological toxicity effect of the pollutant by taking the steady-state biomass array (P, Q, R) as a reaction endpoint, and carrying out uncertainty analysis.

8. The method for measuring and calculating the eco-toxic effect half-effect concentration of environmental pollutants according to any one of claims 1 to 7, wherein the step 8) of calculating the eco-toxic effect half-effect concentration of environmental pollutants is based on a deviation of 50% of a steady-state biomass array of the biological community model; the semi-effective concentration of the pollutant ecotoxicity effect is that the biomass x (x = P, Q, R) of any population deviates from the original steady biomass array (P) under the condition that the simplified biological community reaches the steady state₀,Q₀,R₀) Corresponding to a minimum contaminant concentration at 50% of the biomass of the population.

Technical Field

The invention relates to the field of environment, in particular to a method for measuring and calculating the half-effect concentration of the ecotoxicity effect of environmental pollutants.

Background

The scientific establishment of the water quality standard is the basis of water ecosystem protection and environmental management, and the establishment of the water quality standard is the scientific basis for the establishment of the water quality standard. The scientific basis for establishing the water quality standard is that the water quality standard has complete pollutant ecotoxicology data of the indigenous aquatic organisms and indexes for scientifically judging the toxicity intensity of the pollutants. The semi-effective concentration with high sensitivity and good repeated stability is an important index for measuring the toxicity intensity of the pollutants. According to toxicological data, the half-effect concentration is determined by a reaction endpoint with obvious ecological significance, and the method is a scientific basic method for comparing the ecological toxicity effect of pollutants. The ecological toxicity effect of the pollutants is not only related to the content and chemical form of the pollutants in the water environment and is directly or indirectly influenced by various environmental factors, but also related to an ecological toxicity effect research object and changes along with the change of an ecological system. Various calculation methods proposed for the semi-effective concentration of the ecotoxic effect of the pollutant have defects and need to be further improved by foreign influential institutional organizations such as the United States Environmental Protection Agency (USEPA), the european union research center (EUC), the world economy and cooperation Organization (OECD), and in fact, international scientific research institutes are also researching more complete methods for calculating the semi-effective concentration of the ecotoxic effect of the pollutant. The technical guide issued by organizations such as USEPA, EUC and OECD mainly adopts toxicity data of individual level reaction end points when calculating water quality standards. Although the more microscopic the level of the reaction endpoint, the stronger the causal relationship of the experimental results, the less significant the ecological significance, and the reaction endpoint at the individual level and below is difficult to meet the need for deriving the water quality benchmark. Even multiple reaction endpoints of the same ecological receptor tend to differ in the ability to characterize the adverse effects of pollutants. It is now common practice to select the most sensitive reaction end point as the reaction end point for determining the concentration of the semieffective. However, the toxic effects determined by the most sensitive end-point of the response at the level of an individual do not necessarily reflect the population toxic effects, since the population effects are not necessarily determined by the most sensitive life cycle characteristics. Likewise, the toxic effects identified by the most sensitive reaction endpoint at a population level do not necessarily reflect community or ecosystem toxic effects, since ecological relationships such as competition, feeding, etc. in the ecosystem affect the toxic effects of the contaminant. Although the higher the level of the life building of the ecoreceptors, the greater the capacity of the corresponding reaction end points to comprehensively reflect the toxic effects of the ecosystem, only the reaction end points at the population level can be quantitatively measured at present due to the technical condition limitations. Therefore, the current research on the half-effect concentration of the ecological toxicity effect of the pollutants is mostly limited to single-species toxicity experiments, and ecological correlation among ecological system populations is not considered, so that the authenticity and reliability of research results are reduced.

At present, no related report for scientifically measuring and calculating the half-effect concentration of the ecotoxic effect of the water environment pollutants reflecting the ecological relationship by applying the toxic effect data on the population level of a single species exists. However, the method can further improve the ecological relevance of the half-effect concentration of the ecotoxic effect, is favorable for perfecting a comparison method of the intensity of the ecotoxic effect of the pollutants, is favorable for compacting the scientific basis of the establishment of the water quality standard, is favorable for improving the scientificity of the establishment of the pollutant emission standard and the emission control priority, and promotes the harmonious development of the economic and ecological environment. Therefore, in a water environment comprehensive treatment system, a new and more scientific water environment pollutant ecotoxicity effect half-effect concentration analysis technology reflecting ecological relations is needed to be introduced, and a more scientific pollutant ecotoxicity effect half-effect concentration measurement and calculation method is established.

Disclosure of Invention

The invention aims to solve the technical problem of providing a method for measuring and calculating the half-effect concentration of the ecotoxicity effect of environmental pollutants aiming at the defects related to the background technology.

The invention adopts the following technical scheme for solving the technical problems:

a method for measuring and calculating the semi-effective concentration of the ecological toxic effect of environmental pollutants is based on the experimental result of the toxic effect of single species, a community model is constructed by using the ecological relationship among populations, a plurality of reaction end points on the population level and at different nutrition levels are combined, and the steady-state biomass array (P, Q, R) of the floating community deviates from the original steady-state biomass array (P) under a certain pollutant concentration₀,Q₀,R₀) The degree of the pollutant is used as a criterion to calculate the ecological toxicity effect half-effect concentration of the pollutant; the method specifically comprises the following steps:

step 1), performing a toxicity effect experiment of a single-algae culture system, and calculating the intrinsic growth rate and the environmental tolerance of microalgae populations under different pollutant concentrations;

step 2), carrying out a toxicity effect experiment of the zooplankton population, calculating the survival rate, the reproduction rate, the intrinsic growth rate and the generation time of the zooplankton under different pollutant concentrations, and the female oviposit rate and the population proliferation rate of the zooplankton population under different pollutant concentrations, and analyzing the toxicity effect of the pollutants on the zooplankton population by taking the female oviposit rate and the population proliferation rate as reaction endpoints;

step 3), calculating EC at each reaction end point based on the toxicity effect experiment result of plankton population₁₀、EC₅₀、EC₉₀And 95% confidence interval thereof, analyzing the sensitivity, reliability and stability of the ecotoxicity effect at different reaction end points, and determining the half-Effect Concentration (EC) of the ecotoxicity effect₅₀Constructing a population toxicity effect model at the reaction end point of (1);

step 4), performing a double-algae competition experiment, and calculating competition inhibition parameters of the microalgae;

step 5), carrying out a zooplankton feeding experiment, and calculating the water drainage rate and the feeding rate of the zooplankton to the microalgae;

step 6), carrying out a feeding behavior experiment of the zooplankton, and calculating a feeding selectivity coefficient of the zooplankton for the microalgae;

step 7), constructing a simplified floating community model with competition-feeding effect;

and 8), constructing a plankton community-toxicity effect coupling model, calculating a steady-state biomass array (P, Q, R), and calculating the half-effect concentration by taking the steady-state biomass array as a reaction endpoint.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxicity effect of the environmental pollutants, the method comprises the following specific steps in the step 1):

step 1.1), filtering seawater to add a proper amount of nutrient salt as a culture solution by taking microalgae bred in a laboratory as an object, placing the culture solution in a culture bottle, and culturing in an illumination incubator according to preset culture temperature, salinity, illumination intensity, micro-structure initial density and photoperiod;

step 1.2), setting 3 parallel samples in each group according to a preset pollutant concentration interval; performing species identification and counting under a microscope every day, and finishing the experiment when the population of the experimental object shows decay;

and 1.3) utilizing Logistic growth model fitting to obtain the intrinsic growth rate and the environmental tolerance of the microalgae, and analyzing the toxic effect of the pollutants on the microalgae population.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxicity effect of the environmental pollutants, the step 2) comprises the following specific steps:

step 2.1), zooplankton monomer culture:

step 2.1.1), selecting healthy and active mature females of zooplankton, and placing 1 in each spawning bottle containing culture solution;

step 2.1.2), setting 10 parallel samples in each group according to the preset concentration interval of pollutants, and culturing at constant temperature according to the preset culture temperature; checking and counting the number of spawned eggs, the number of hatched larvae and the survival condition of a parent every day, removing the larvae, simultaneously changing culture solution water according to the proportion of about 1/2, and adding bait algae; the experiment was carried out until the female died;

step 2.1.3), calculating survival rate, reproduction rate, intrinsic growth rate and generation time of zooplankton, and analyzing toxic effect of pollutants on zooplankton population;

step 2.2), carrying out accumulative culture of zooplankton population:

step 2.2.1), quantitatively moving a plurality of lively and strong zooplankton which are pre-cultured under the same conditions to be placed in a beaker filled with culture solution;

step 2.2.2), setting 3 parallel samples in each group according to the preset concentration interval of pollutants, culturing at constant temperature until the population growth reaches a peak and begins to decline; feeding bait once every 24h during the experiment; counting the total individual number, the egg-carrying individual number and the number of fallen summer eggs of the zooplankton every day;

and 2.2.3) calculating the egg laying rate and the population proliferation rate of female zooplankton, and analyzing the toxic effect of pollutants on zooplankton populations.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxicity effect of the environmental pollutants, the step 4) comprises the following specific steps:

step 4.1), mixing the experimental microalgae two by two, and setting the initial inoculation biomass of the microalgae according to the density of algae cells in a culture solution and the biological volume of a single algae cell so that the biomass ratio of the co-cultured microalgae is 1: 1;

and 4.2) fitting by using a Lotka-Volterra competition model to obtain a competition inhibition parameter.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxicity effect of the environmental pollutants, the step 5) comprises the following specific steps:

step 5.1), domesticating and culturing the pre-cultured zooplankton in corresponding microalgae to be ingested for 3-5d, and starving for 24 h;

step 5.2), carrying out experiments in beakers, wherein the microalgae density is a preset optimal feeding density threshold, a plurality of zooplanktons are added into each beaker, each experimental group is provided with 3 parallel samples, and a control group without the zooplanktons is additionally arranged; covering the experimental beaker with black cloth and culturing for 24h under a dark condition;

step 5.3), counting after 24 hours by adopting a bait concentration difference method, fixing the algae liquid by using the Ruoge liquid, counting by using a blood ball counting plate under a microscope and calculating the cell density of the algae;

and 5.4) calculating the water drainage rate and the food intake rate of the zooplankton to the microalgae.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxicity effect of the environmental pollutants, the step 6) comprises the following specific steps:

step 6.1), mixing the microalgae two by two, feeding the selected zooplankton, determining the mixing ratio according to the biological volume of a single algae cell to ensure that the biomass ratio of the two microalgae is 1:1, adding a plurality of zooplanktons into each beaker, arranging 3 parallel samples in each experimental group, and arranging a control group without the zooplanktons; covering the experimental beaker with black cloth and culturing for 24h under a dark condition;

step 6.2), calculating the ingestion rate of the zooplankton to the microalgae by adopting a bait concentration difference method;

and 6.3) determining the feeding selectivity coefficient according to the feeding degree of the zooplankton to different microalgae.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxicity effect of the environmental pollutants, the step 8) comprises the following specific steps:

step 8.1), based on the analysis result of the reaction end point, embedding a population toxicity effect model into a plankton community model by taking the population toxicity effect reaction end point and the toxicity effect semi-effective concentration which have obvious ecological significance as model parameters, and constructing a plankton community-toxicity effect coupling model, so that a plurality of reaction end points on different nutrition levels and population levels are combined to calculate the biological community toxicity effect;

and 8.2) calculating a steady-state biomass array (P, Q, R) of the plankton community by using a coupling model and a Bootstrap sampling mathematical statistic method, measuring and calculating the semi-effective concentration of the ecological toxicity effect of the pollutant by taking the steady-state biomass array (P, Q, R) as a reaction endpoint, and carrying out uncertainty analysis.

As a further optimization scheme of the method for measuring and calculating the half-effect concentration of the ecotoxic effect of the environmental pollutants, the step 8) of calculating the half-effect concentration of the ecotoxic effect of the pollutants takes the deviation of 50% of a steady-state biomass array of the biological community model as a judgment basis; the semi-effective concentration of the pollutant ecotoxicity effect is that the biomass x (x = P, Q, R) of any population deviates from the original steady biomass array (P) under the condition that the simplified biological community reaches the steady state₀,Q₀,R₀) Corresponding to a minimum contaminant concentration at 50% of the biomass of the population.

Compared with the prior art, the invention adopting the technical scheme has the following technical effects:

according to the invention, a biological community-toxicity effect coupling model is constructed through the ecological relationship among biological populations, the single species population toxicity effect data is used for measuring and calculating the half-effect concentration of the ecological toxicity effect of the pollutant, and the ecological correlation of the toxicity effect of the pollutant is considered, so that the accuracy and the scientificity of the measurement and calculation are improved; the invention can fully utilize a large amount of existing single species toxicity effect experimental data and save the cost. In addition, the biotoxicity experiments related to the invention are all routine experiments, and a monitoring biological community model designed aiming at monitoring biology can be applied to different pollutants, so that the biological toxicity experiment is convenient to popularize and use in the wide water quality environment monitoring departments.

Drawings

FIG. 1 is a schematic diagram of a technical route for calculating the ecotoxicity threshold concentration of pollutants;

FIG. 2 is a schematic diagram of a simplified experimental ecosystem;

FIG. 3 is a graph showing the change of a biocenosis steady-state biomass array consisting of chrysophyceae, glochidion, and brachiarius pleionis in Qingdao with the concentration of copper in pollutants.

Detailed Description

The technical scheme of the invention is further explained in detail by combining the attached drawings:

the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. In the drawings, components are exaggerated for clarity.

In the embodiment, sensitivity, reliability and stability of a reaction end point are analyzed on the basis of a plankton population toxicity effect experiment, model parameters are obtained, a plankton community-toxicity effect coupling model is further constructed, and the pollutant half-effect concentration is calculated. The scientificity of the method can be evaluated by simplifying the goodness of fit of the plankton community experimental result analysis coupling model and verifying the half-effect concentration calculation result, as shown in fig. 1. The experimental ecosystem is simplified as shown in fig. 2.

1. Ecological toxicity effect experiment and parameter acquisition:

(1) toxicity effect experiment of single algae culture system

Using laboratory breeding to obtain large red algae of Qingdao (Pandalia glauca L.) (Platymonas helgolandica) And dinoflagellates such as Strongylocentrotus (Haematococcus)Isochrysis galbana) Filtering seawater, adding proper amount of nutrient salt as culture solution, placing into 1000mL conical flask, and culturing in light incubator. The culture temperature is 15 deg.C (or 23 deg.C, respectively matched with suitable culture temperature of two zooplankton in later experiment), salinity is 32, pH is 8.0, and illumination intensity is 60 μmol m^-2s^-1Initial densities were all 1X 10⁴cells mL^-1And a light period 12L: 12D. The heavy metal copper contaminant is provided with 6 concentration gradients, including a control sample. Each set was set with 3 replicates. 5mL of the culture medium was taken every 24 hours, and the fixed solution was added thereto to carry out species identification and counting under a microscope. And finishing the experiment when the experimental object population shows decay. And fitting by utilizing a Logistic growth model according to the experimental result to obtain parameters such as the intrinsic growth rate, the environment accommodation capacity and the like of the microalgae.

(2) Competition experiment with diatom

Mixing the large Platymonas subcordata, the Isochrysis galbana and the like, setting the initial inoculation biomass of the microalgae according to the cell density of the algae in the culture solution and the biological volume of a single algae cell, ensuring that the biomass ratio of the co-cultured microalgae is 1:1, and ensuring that other culture conditions and detection indexes are the same as those of a single algae toxicity effect experiment. And fitting by using a Lotka-Volterra competition model according to the experimental result to obtain a competition inhibition parameter.

(3) Zooplankton population toxicity effect experiment

Healthy and active mature females of Brachionus plicatilis are selected for monomer culture and are respectively put into a 6-hole culture plate with 15 mL. The concentration of the contaminant was set up with 6 concentration gradients, including control samples, with 10 replicates per set. The experiment is carried out at a constant temperature of 23 ℃, the number of eggs laid, the number of hatched larvae and the survival condition of the parent are checked and counted every day, the larvae are removed, meanwhile, the seawater is changed according to the proportion of about 1/2, and bait algae is added until the females die. According to the experimental result, the survival rate, the reproduction rate, the intrinsic growth rate, the generation time and the like of the zooplankton can be calculated.

The active, robust and pre-cultured brachypodium plicatilis (initial density of 10 ind/mL) under the same conditions is quantitatively transferred to a beaker filled with 300mL of culture solution for colony accumulation culture. The concentration of the contaminant was set with 6 concentration gradients, including control samples, with 3 replicates per group. The experiment was incubated at 23 ℃. The culture time is until the population reaches a peak and begins to decline. Baits were fed every 24h during the experiment. Counting the total number of individual zooplankton, the number of egg-carrying individual and the number of fallen summer eggs (putting back to the original culture after counting) every day, repeating for three times continuously, and calculating the average number. And calculating the egg laying rate of female zooplankton, the population proliferation rate and the like according to the experimental result.

(4) Feeding and choking behavior experiment of zooplankton

Separately feeding dinoflagellates such as Pandalus islets and Glochidiodes globosa to Brachypoda rufimbriata. The zooplankton is obtained by laboratory breeding, and before the experiment, the pre-cultured zooplankton is domesticated and cultured in the corresponding microalgae to be ingested for 3-5d respectively, and then starved for 24 h. The experiment is carried out in 150mL beakers, the volume of the experimental algae liquid is 50mL, the microalgae density is set as the optimal feeding density according to the preliminary experiment, the temperature is 23 ℃, 10ind/mL brachiarius pleionis is added into each beaker, 3 parallel samples are arranged in each experimental group, and a control group without zooplankton is additionally arranged. The experimental beaker was covered with black cloth and incubated in the dark for 24 h. Counting after 24 hours by adopting a bait concentration difference method, fixing algae liquid by using the Lugoji liquid, counting by using a blood ball counting plate under a microscope, calculating the cell density of algae, and calculating the water filtration rate and the ingestion rate of the microalgae by the Chinese philosophila (or Brachionus plicatilis) according to an experimental result.

Mixing the green island large flat algae, the dinoflagellates such as the ball and the like, feeding the brachiocephalus plicatilis, determining the mixing ratio according to the biological volume of a single algae cell, and enabling the biomass ratio of the two microalgae to be 1:1, wherein the other experimental conditions and steps are the same as the above. And calculating the ingestion rate of the Brachionus plicatilis on the microalgae by adopting a bait concentration difference method, and calculating the ingestion selectivity coefficient of the Brachionus plicatilis according to the ingestion degree of the Brachionus plicatilis on different microalgae.

(5) Simplified biocenomic toxicity effect experiments

Mixing the physosiphon glauca and the dinoflagellates such as the Strongylocentrotus nudus to ensure that the biomass ratio of the co-cultured microalgae is 1:1, inoculating Brachionus plicatilis into the microalgae mixed solution, and adding pollutants. The initial inoculation of microalgae biomass, zooplankton biomass and concentration interval of added contaminants were as above. Selecting an active, robust and pre-cultured individual under the same condition for zooplankton, performing acclimation culture in corresponding microalgae mixed liquor for 3-5d before experiment, and starving for 24h to empty intestinal tract. The experiment was carried out in a 10L glass vessel and incubated at 23 ℃. Each experimental group was provided with 3 replicates and a control group without added contaminants. Other culture conditions were the same as those in the single algae toxicity effect experiment. The change of the species and the number of the counted plankton is observed every day, and the counting method is the same as the corresponding experiment. And determining the end time of the experiment according to the stable duration of the number of the plankton populations in the experimental community.

2. Reaction end point analysis and population toxicity effect model construction:

according to the result of the population toxicity effect experiment, a Log-logistic model is used for calculating EC under different reaction end points (parameters such as intrinsic growth rate, environmental tolerance and the like of microalgae population, survival rate, reproduction rate, intrinsic growth rate, generation time, female oviposition rate, population proliferation rate, water filtration rate, ingestion rate and the like of zooplankton population)₁₀、EC₅₀、EC₉₀And 95% confidence intervals thereof, and analyzing the sensitivity, reliability and stability of the population toxicity effect at different reaction endpoints.

And (4) conclusion: through reaction end point analysis, parameters such as intrinsic growth rate, environmental tolerance and the like of microalgae population and parameters such as survival rate, intrinsic growth rate, water filtration rate, ingestion rate and the like of zooplankton population are found to have higher sensitivity, reliability and stability, and can be used as a reaction end point on the population level to construct a population toxicity effect model for measuring and calculating half-effect concentration of the ecotoxicity effect.

3. Establishing a biological community-toxicity effect coupling model:

according to parameters measured by a diatom competition experiment and a zooplankton feeding and food selecting behavior experiment, a simplified plankton community model is established based on a Logistic growth model and a Lotka-Voterra predation model, wherein the density restriction is considered for the growth of microalgae, and the density restriction is not considered for the growth of zooplanktons. The influence of the pollutant concentration on the simplified plankton community model coefficient is constructed through the population toxicity effect functions of a plurality of different reaction end points, so that the population toxicity effect model is embedded into the plankton community model to construct a plankton community-toxicity effect coupling model.

And (4) analyzing results: a simplified plankton community model established by using ecological relations of competition-ingestion and the like can reflect the ecological toxicity effect of pollutants on plankton communities by embedding a population toxicity effect model.

4. And (3) measuring and calculating the half-effect concentration:

under the experimental conditions, the simplified plankton community model has a unique steady-state biomass array (P)₀,Q₀,R₀). Under the condition of a certain pollutant concentration, the simplified plankton community steady-state biomass array (P, Q, R) changes and deviates from the original steady-state biomass array (P)₀,Q₀,R₀) Here we will simplify the deviation of the biomass x (x = P, Q, R) of any population from the orthostatic biomass array (P) under steady state conditions for the biological community₀,Q₀,R₀) And taking the minimum pollutant concentration corresponding to 50% of the biomass of the population as the biological community ecotoxicity effect semi-effective concentration, and carrying out uncertainty analysis on the semi-effective concentration by applying Bayes transformation and a Monte-Carlo method.

And (4) conclusion: although each reaction end point corresponds to a half-effect concentration, after the reaction end points are embedded into the simplified biological community model, the minimum half-effect concentration determined by a certain reaction end point is not necessarily the minimum concentration of 50% deviation of the steady-state biomass array of the simplified biological community model due to different sensitivities of the coupling model to parameter changes, and the deviation degree of the steady-state biomass array is judged by calculating the difference between the biomass of any population under the condition of certain pollutant concentration and a control experiment. The result of the calculation of the ecotoxicity effect half-effect concentration of the heavy metal copper is 107.7 +/-6.7 mu g/L.

5. And (3) verifying the measurement result of the half-effect concentration:

the determination result (P) of the biomass of the planktonic organism population under each pollutant concentration in the biocenosis experiment is simplified_t, Q_t, R_t) Corresponding result to model calculation(P _t , Q _t , R _t )Comparing, calculating to obtain model goodness of fitR ²>0.9, Steady State Biomass array calculated by test model(P*,Q*,R*)There was no significant difference from the experimentally determined steady state biomass arrays (P, Q, R), thus verifying the reliability of the model calculations.

By applying the model of the invention, as shown in fig. 3, based on the toxicity effect experimental data of single species populations such as physostymonas major, chrysomeles and the like, Brachionus plicatilis and the like, the half-effect concentration of the ecological toxicity effect of the pollutant is calculated by taking the deviation of the steady-state biomass array of the simplified plankton population as a criterion, and is basically consistent with the measurement result of the simplified biological population formed by physosiphora major, chrysomeles and the like and Brachionus plicatilis. The result further verifies the operability and reliability of measuring and calculating the half-effect concentration of the ecological toxic effect of the pollutant by single species toxicity effect data through a biological community-toxicity effect coupling model, and simultaneously shows that the method has certain application value in measuring and calculating the half-effect concentration of the ecological toxic effect of the pollutant in the water environment.

It will be understood by those skilled in the art that, unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the prior art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

The above-mentioned embodiments, objects, technical solutions and advantages of the present invention are further described in detail, it should be understood that the above-mentioned embodiments are only illustrative of the present invention and are not intended to limit the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the protection scope of the present invention.