CN204649726U - A kind of experimental provision studying midge chronic toxicity - Google Patents

Abstract

The utility model discloses an experimental device for studying the chronic toxicity of chironomids, which is composed of a peristaltic pump, an aeration pump, a stock solution container, an experiment container and a waste liquid tank; the stock solution container is connected with the experiment container, and the aeration pump is connected with the The experimental container is connected, and the waste liquid tank is connected to the experimental container through a connector. This device solves the additional interference caused by the need to control the concentration of pollutants in the water environment during the water change process in the chronic toxicity experiment of chironomus. And the status quo that disturbs the experimental environment and affects the data results.

Description

An experimental device for studying the chronic toxicity of chironomids

technical field

The utility model belongs to the technical field of ecotoxicity evaluation tests, in particular to an experimental device for studying the chronic toxicity of chironomids.

Background technique

The protection of aquatic organisms depends on the water quality basis and standard system, and the aquatic organism toxicity data is an important supporting data for deriving the benchmarks of various pollutants in the water quality environment. However, my country lacks the toxicity research of native organisms, so the establishment of water quality standards mostly relies on foreign countries. Therefore, when applying national standards to local water body protection, it is necessary to verify according to the toxicity of local aquatic organisms. As a common species in natural water bodies, chironomids are rich in species and numerous in individuals. They are indicator organisms for monitoring the water environment and pollution status. At the same time, because they are easy to cultivate in the laboratory, have a short life cycle, an important position in the food chain, and a wide range of pollution tolerance, etc. Some species of chironomus have been listed as model organisms for toxicity research by the US Environmental Protection Agency and the European Union, and are excellent representative organisms for local biological species verification. The organic matter system is recommended as the best experimental environment, but with the adsorption of pollutants by sediments and the volatility of pollutants, it is difficult to ensure the constant content of pollutants in the experimental environment in actual toxicity test operations. This also greatly affects the credibility and applicability of the experimental results. Therefore, designing and improving the experimental device that can effectively study the chronic toxicity of chironomids in the water sediment system will not only help the protection of aquatic organisms and aquatic ecology, but also provide strong technical support for the establishment of local water quality benchmarks in my country.

Utility model content

The purpose of the utility model is to provide an experimental device for studying the chronic toxicity of chironomids.

In order to achieve the above object, the technical solution adopted by the utility model is:

An experimental device for studying the chronic toxicity of chironomids, which consists of a peristaltic pump, an aeration pump, a stock solution container, an experimental container, and a waste liquid tank; the stock solution container is connected to the experimental container, the aeration pump is connected to the experimental container through an aeration tube, and the waste The liquid cylinder is connected with the experimental container through a connector.

The peristaltic pump is arranged between the stock solution container and the experimental container for flow control.

Advantage of the utility model:

The experimental device of the utility model for studying the chronic compound toxicity of chironomids in sediments is reasonable in design, simple in device structure, convenient in installation and layout, simple in use and operation, and can ensure the water medium in the experimental container without causing additional interference to the tested organisms. The concentration of pollutants in the medium is stable, and the interference caused by other interference factors except pollutants to the toxicity test can be avoided to the greatest extent, which can ensure the smooth development of the chronic toxicity experiment of chironomids in the water-sediment system. These experiments play a guiding role and contribute to the smooth and effective development of aquatic toxicity research in my country.

Description of drawings:

Fig. 1 is the utility model utilizes water sediment system to carry out chironomid chronic toxicity experiment structure schematic diagram;

Fig. 2 is the concentration of influent ammonia nitrogen and effluent ammonia nitrogen measured under the experimental state;

Figure 3 is the experimentally observed chironomus eclosion time and the number of eclosions;

In Figure 1, 1-contaminated stock solution; 2-peristaltic pump; 3-spike culture solution; 4-waste liquid; 5-aeration pump; 6-flexible plastic tube; 7-aeration tube; 8-sediment; 9 -stock solution container; 10-experimental container; 11-waste liquid tank.

Detailed ways

Example 1:

Below in conjunction with accompanying drawing and embodiment the utility model is further described;

An experimental device for studying the chronic toxicity of chironomids, consisting of a peristaltic pump 2, an aeration pump 5, a stock solution container 9, an experimental container 10, and a waste liquid tank 11; the stock solution container 9 is connected to the experimental container 10, and the aeration pump 5 The air pipe 7 is connected to the experimental container 10, and the waste liquid cylinder 11 is connected to the experimental container 10 through a connector.

The overlying water in the beaker 9 is poured into the waste liquid tank 11 by utilizing the pressure difference principle of the connector, and a certain rate is maintained so that the liquid level of the overlying water in the experimental container remains basically unchanged.

Application example 1

The 21-day chronic toxicity experiment of Chironomus riparius was carried out using the experimental device of Example 1. According to the OECD 219 international experimental standard specification, the toxic effect of ammonia nitrogen in water on chironomid larvae was studied by the method of adding standard water-sediment system.

According to the acute test data and the living characteristics of chironomus larvae in the bottom mud, 6 test groups and a control group were set up: the ammonia nitrogen concentrations of the spiked culture solution were 25, 50, 100, 200, 400 and 800mg/L, and each group Set up three parallels. The experimental container is a 600mL glass beaker, in which 400mL of spiked culture solution with corresponding ammonia nitrogen concentration of pH=6.5-7 is added, and 100g of aged sediment (wet) is added to configure a sediment-water environment system. The pollution source liquid enters the test container through the peristaltic pump, and the flow rate of the peristaltic pump is kept at 0.3mL/s. The system was pre-aged for 7 days before the start of the test. About 5 days before the start of the test, fresh chironomus eggs were picked out in a petri dish, and after 3 days of incubation, 20 first-instar larvae were placed in each experimental container with a blunt straw. , start aeration after 24 hours, about 2 bubbles per second; grind 4g of fish food into powder and add it to the culture medium to dilute to 200mL, add 1mL dropwise to each test container, once every two days; control the temperature at 25±1°C , t (light): t (dark)=16h:8h. During the test, water was taken every 4 days to measure the ammonia nitrogen content, and the eclosion time of chironomids and the number of chironomids that emerged each day were recorded. At the same time, the eclosion rate of the control group should not be less than 70% to ensure the accuracy of the experiment.

The concentration of ammonia nitrogen in the influent and effluent water is shown in Figure 2, and it can be seen that there is no significant difference between the two. On the basis of the eclosion time and number of eclosions observed in the experiment (as shown in Figure 3), use SPSS correlation analysis software to simulate and calculate the EC20 of ammonia nitrogen on the eclosion time of chironomus larvae, and add this value into the ammonia nitrogen biotoxicity database for use Ammonia nitrogen water quality standard formulation.

Claims (1)

1. An experimental device for studying the chronic toxicity of chironomids, characterized in that: it consists of a peristaltic pump (2), an aeration pump (5), a stock solution container (9), an experimental container (10), and a waste liquid tank (11) The stock solution container (9) is connected with the experimental container (10), the aeration pump (5) is connected with the experimental container (10) by the aeration pipe (7), and the waste liquid cylinder (11) is connected with the experimental container (10) by a connector connected; The peristaltic pump (2) is arranged between the stock solution container (9) and the experimental container (10), and is used to control flow.