EP2074416A2

EP2074416A2 - Water quality control system

Info

Publication number: EP2074416A2
Application number: EP07858543A
Authority: EP
Inventors: Yves Joly
Original assignee: Individual
Current assignee: Individual
Priority date: 2006-10-11
Filing date: 2007-10-10
Publication date: 2009-07-01
Also published as: WO2008043956A2; WO2008043956A3; FR2907224B1; FR2907224A1

Abstract

The invention relates to a water quality control system. The proposed system is modular and is composed of a base module (M) capable of allowing a coupling between a chemical/electrochemical analysis unit (2) and at least one unit (100) of exposure of living aquatic organisms for biological analyses. This module (M) may be extended by coupling additional exposure units.

Description

SYSTEM FOR MONITORING THE QUALITY OF WATER.

The invention relates to a system for controlling the quality of water especially in the presence of chemical elements such as heavy metals (mercury, lead, cadmium, nickel, zinc , copper); organic molecules (Polycyclic Aromatic Hydrocarbons, PAHs

(Polyaromatic hydrocarbons), Dioxins (PCDD / F polychlorinated dibenzo-p-dioxins and dibenzofurans), Pesticides, PCBs

(polychlorinated biphenyls: chlorinated chemical derivatives).

To date, there are water quality control systems based on biological measurements made from aquatic organisms (typically fish or molluscs used as sentinels.

Indeed, the level of contamination of a lake or a river or more generally of any water, in heavy metals or organic molecules, can be evaluated by measuring the concentrations of these pollutants in the exposed animals, the latter becoming then biosentinelles. To do this, it is necessary to determine the relationships between the concentration of the metal in the medium and that in the biosentinelle.

By observing sentinels (that is, organisms exposed to polluting or non-polluting chemicals), various changes in molecular, biochemical, cellular, physiological, genetic or behavioral levels can be measured. These changes are classically referred to as effect biomarkers and exposure biomarkers. They reveal the present or past exposure of an individual to at least one toxic chemical. Biomarkers allow both spatial and temporal monitoring, giving a dynamic image of variations in the quantities of pollutants present in the aquatic environment studied. They also make it possible to evaluate the state of "suffering" of organisms, which is the goal of any monitoring of the state of health of the ecosystem.

In particular, biomarkers described as general stress indices reflect an organism's response to a set of pollutants without determining the nature of these pollutants. These are the air survival time of mussels (stress stress test), micronuclei frequency in midge gill cells, membrane lysosomal stability, lipofuscin accumulation, and determination of neutral lipids of the digestive glands of mussels.

Biomarkers qualified as specific stressors reflect an organism's response to a family of pollutants. These are metallothioneins, which are proteins that can be induced by heavy metals. The potential of metallothionein has been evaluated as a biomarker of exposure to toxic metals, particularly for cadmium Cd, and as a biomarker of deleterious effects caused by these metals. Biochemical biomarkers allow early detection of exposure and response of aquatic organisms to pollutants. For example, the induction of enzymatic activity EROD (ethoxyresorufin O-deethylase) in fish is related to the presence of PAHs, PCBs, dioxins and coplanar molecules.

Continuous water monitoring systems, based on the single bioaccumulation phenomenon observed on living aquatic organisms, are systems for establishing the existence of pollution. They do not make it possible to carry out precise quantitative measurements on all the polluting substances present in a water. And in any case, these systems do not have the means of measurement to know the biological impact of different types of pollution on organisms because of the very nature of the measurements of biological variables. These systems are unsatisfactory when one seeks to have continuous control of water to establish relationships between pollution and the impact of this pollution on living aquatic organisms. The Applicant has noted that existing water quality monitoring systems only provide partial results because of the diversity of biomarkers to be measured, the diversity of species to be observed and the bioaccumulation phenomenon that occurs. may be different from one organism to another. In particular, none of these systems provides sufficient results to know the real impact between pollution of heavy metals and other toxic products and effects on living organisms. Also known from WO2004 / 069751 an automatic water quality control device. The described apparatus makes it possible to establish the existence of a pollution caused by chemicals causing physiological changes in fish, in particular the respiratory behavior and the movements of the body. To this end, each fish is placed in a bin equipped with two electrodes for measuring the electrical signals produced by its respiratory behavior. From tests to know different reference parameters, thresholds are established and can trigger alarms. In addition, the apparatus includes a sensor for measuring parameters such as pH, temperature, conductivity, and diluted oxygen level of the water. The present invention aims to overcome the disadvantages of the prior art.

The present invention makes it possible to solve the problem of obtaining sufficient measurement results to determine the quality of a water and, in the presence of pollution, the impact of this pollution on living aquatic organisms; the system according to the present invention being for this purpose modular, scalable and providing means of discriminating parameters to combine their diversity to specify the measurement.

In fact, the continuous water control system consists of a basic module able to allow a coupling between a chemical and electrochemical analysis unit and at least one exposure unit of living aquatic organisms for biological analyzes, this unit being referred to as the exposure unit. This module can be extended by coupling additional exposure units and / or adding independent units.

To this end, the subject of the present invention is a water quality control system comprising a basic module comprising at least one exposure unit of living aquatic organisms called exposure unit for biological analyzes;

- A water inlet unit to be analyzed comprising a connection for receiving the water to be analyzed and an output connection supplying the exposure unit which comprises an outlet connection discharging this water;

at least one control exposure unit containing control organisms representative of the species or species placed in the exposure unit and comprising a connection making it possible to receive a reference water and an exit connection for evacuating this water,

and a chemical and electrochemical analysis unit coupled to the output link of the water unit to be analyzed supplying the exposure unit, said unit being coupled to the control exposure unit by the link allowing receive and analyze the reference water (E _R );

Said base module (M) thus allowing a coupling under the same conditions of chemical and electrochemical measurements with biological measurements. Biological measurements are based on the phenomena of biomarkers, bioaccumulation and bioindicators. This coupling under the same measurement conditions makes it possible to establish relationships between the pollution and the impact of this pollution on living aquatic organisms. This coupling also makes it possible to overcome the bias of the measurements because all the measurements are carried out under the same conditions, including for the measurements of the reference parameters.

The water quality control system according to the invention thus makes it possible to detect and measure the presence of chemical elements such as heavy metals (mercury, lead, cadmium, nickel, zinc, copper); and organic molecules (Polycyclic Aromatic Hydrocarbons, PAHs

(Polyaromatic hydrocarbons), Dioxins (PCDD / F polychlorinated dibenzo-p-dioxins and dibenzofurans), Pesticides, PCBs (polychlorinated biphenyls: chlorinated chemical derivatives).

Indeed, the chemical analysis allows for example measurements of BOD5 (Biological Oxygen Demand over 5 days), COD

(concentration of organic or inorganic matter, dissolved or suspended in water, through the quantity of oxygen necessary for their total chemical oxidation), MES (suspended solids),

Ntotal, NKjeldahl, Ptotal, conductimetry, Ca, Mg, electrochemical analysis allows for example the measurement of heavy metals, PAH, etc.

The biological analysis is carried out on the aquatic organisms exposed in the analyzed water and makes it possible to measure the concentrations of the pollutants in these organisms and to determine the relationships between the concentration of metals in the environment and that in the sentinel organisms.

With the coupling of chemical-electrochemical measurements and biological measurements, good conditions of biotoxicity measurements are obtained by limiting the biases of the measurement protocols. The measurements obtained by means of this control system make it possible, on the one hand, to quantify the presence of different heavy metals in water under the same conditions and, on the other hand, to establish relationships between these elements and their biological fraction. accumulated by aquatic organisms, according to the organisms and according to the toxic elements (pollutants).

The system includes links for receiving water

(inlet) and connections for discharging this water (outlet), said connections comprising conduits or pipes and devices allowing a continuous flow of water with flow control (for example adjustable flow valves) and the closing of the flow if necessary. The chemical / electrochemical water analysis unit comprises at least one potentiostat to which measurement electrodes are connected, at least one of which is connected to the water supply connection of the exposure unit for measurement purposes. organic. To obtain significant measurement results, an exposure unit comprises several aquariums that is to say conventional aquariums formed by independent receptacles each supplied with water to be analyzed by a connection with the input unit and having an evacuation of this water by an exit link, each aquarium of an exposure unit containing aquatic organisms of the same species thus constituting a population of organisms from which samples can be taken for example 2 or 3 organisms per aquarium according to the biological analysis protocol defined, periodically over a predetermined duration, which is a function of the number of organisms and the sampling frequency, to perform biological measurements on said predetermined time.

For best results an exposure unit has at least three aquariums each containing aquatic organisms constituting a biosentinella population.

The aquariums are placed in an open, semi open or closed system (ie with a continuous water supply and a continuous evacuation, or storage during fixed term or without evacuation); all under the same conditions, in particular temperature, light and oxygenation and fed by the same flow of water (E) provided by the unit of water to be analyzed by means of the input link which feeds them separately.

For the same reasons, the control exposure unit comprises at least two aquariums placed under the same conditions, in particular temperature, light and oxygenation and supplied with the same reference water flow rate (E _R ).

In order to overcome the variations of the measurement temperature conditions, the exposure unit and the control exposure unit comprise means for regulating the temperature of the water at a constant temperature. To obtain operation in an open or semi-open or closed system, the connections comprise devices for regulating the flow of feed and outlet water (for example valves).

Preferably these control means consist in placing the aquariums of an exposure unit in the same tank containing water (tap for example) at a fixed temperature, the aquariums thus being in a water bath.

The aquariums of the control exposure unit are also placed in a bain-marie tank, this tank being able to be the same as that of the exposure unit.

In order to overcome the majority of toxic substances, the water inlet unit to be analyzed comprises several tanks for diluting this water with a reference water. In this way, at the outlet of each of the dilution tanks, there is obtained a water to be analyzed having a given degree of dilution, different or different from one tank to another. The system comprises a plurality of exposure units (exposure unit of the base module and one or more additional exposure units) fed by these bins so as to have a dilution range. In the case where the base module is coupled to one or more exposure units, at least two exposure units contain either water with the same dilution ratio and organisms of different species, or different dilution rates and organisms of the same species, or any combination possible. This allows measurements of different toxic substances.

At a minimum, the control exposure unit contains at least two aquariums, one containing positive control organisms, consisting of aquatic organisms of the same species as in the exposure units, but which have been induced by contact with a control organism. first toxic substance or mixture of toxic substances, and negative control organisms consisting of aquatic organisms of the same species as the positive controls but without induction by toxic substance.

In an alternative embodiment, the control exposure unit has three aquaria, the third comprising organisms placed in standard water and being connected to an additional chemical / electrochemical measurement unit to provide absolute reference measurements.

In order to condition the different species of aquatic organisms to the exposure conditions of the exposure units, the system also comprises one or more holding units (or quarantines), in which the different organisms are placed before being put in the exposure units used for measurements.

To make the system suitable for easy installation regardless of the site, the basic module that composes it and additional units, are placed in a modular, removable and movable cabin.

Other features and advantages of the invention will become clear from reading the description which is given below and which is given by way of example illustrative and not limiting and with regard to the figures in which:

FIG. 1 represents the diagram of a basic module composing the control system according to the invention; FIG. 2 represents the diagram of a system with extensions to the basic module according to the invention;

FIG. 3 represents an embodiment diagram of the water inlet unit to be analyzed,

FIG. 4 represents a diagram of a first practical example of embodiment,

FIG. 5 represents a diagram of a second practical example of embodiment.

FIG. 6 represents a diagram of the control exposure unit according to a variant embodiment (three aquariums).

The system described below and illustrated by the various figures makes it possible to couple chemical and electrochemical measurements with biological measurements based on the phenomena of biomarkers, bioaccumulation and bioindicators. Bioaccumulation is the process by which a living organism absorbs a substance at a rate greater than that with which it excretes or metabolizes it. Bioaccumulation refers to the sum of the direct and indirect dietary uptake of an element by the exposed aquatic animal species.

The chemical measurements make it possible, for example, to measure: BOD5, COD, MES, Ntotal, NK, eldahl, Ptotal, conductivity, Ca, Mg) and the electrochemical measurements make it possible, for example, to measure heavy metals, PAHs, etc.

By a coupling of chemical / electrochemical measurements operated on the water to be controlled and in which will be If living aquatic organisms are placed with biological measurements on these organisms, good biotoxicity measurement conditions are obtained by limiting the biases of the measurement protocols. The measurements thus obtained make it possible, on the one hand, to quantify the presence of different heavy metals in water under the same conditions and, on the other hand, to establish relationships between these elements and their bio-accumulated fraction by aquatic organisms. according to the organisms and according to the toxic elements (pollutants).

The proposed system also makes it possible to carry out a continuous control of the pollution of a water by means of measurements able to allow discrimination on the various parameters related to the phenomenon of bioaccumulation with a view to establishing a better correlation between the pollutants in the water and the real impact on living aquatic organisms.

FIG. 1 shows the control system proposed by the invention. This system includes a basic module M. To this basic module, additional units can be added to discriminate more parameters and thus obtain a greater number of significant measurements.

In the following, reference water E _{R is referred to} , water which is the reference element with respect to the water to be controlled E. This reference water E _R may be a normalized water E _N OR a control water E _τ more ordinary and therefore less expensive (tap water for example).

Feeding or discharging connections are respectively continuous water supply channels or continuous water discharge. These channels may be polyethylene tubes or Teflon or PVC. They are equipped with valves to adjust the input and output flow and if necessary to close the flow circuit. The supply links thus allow operation in an open system, the flow then being continuous (valves open input and output), or a semi-open system operation, the system being open and then closed for a specified time and then again open and of course a closed system operation. The connections also allow connections to allow chemical / electrochemical analyzes.

The basic module M comprises:

- A water inlet unit 1 connected by the link 10 forming the water inlet to be analyzed E (river, lake etc.). This unit 1 comprises a storage tank of a given volume V of water to be analyzed, a chemical / electrochemical analysis unit 2 coupled to the output link 3 of the water inlet unit 1 by the link 20, - an exposure unit 100 continuously supplied with water to be analyzed by a water supply connection 3, the water being discharged continuously through a connection 4 of outlet water S,

a control exposure unit 50 supplied with reference water E _R (standard water E _N OR control water E _τ ) through a reservoir 5, a supply link 6 and an evacuation link 7, this unit 50 being also connected to the chemical and electrochemical analysis unit 2.

The chemical and electrochemical analysis unit 2 makes it possible to carry out measurements on the inlet water E (water whose quality control is carried out) and on the reference water used for the control exposure unit.

The exposure unit 100 comprises several aquariums, preferably three aquariums 101, 102, 103 supplied with an open, semi open or closed system via the link 3, at a predetermined flow rate d. These aquariums contain the same species of living aquatic organisms. These organisms live in aquariums and are subject to the same conditions namely water temperature, water from the input unit. Thus, the exposure unit allows have at each biological analysis several batches of measurements obtained under the same conditions, 3 batches in the example.

Each aquarium thus constitutes a population of organisms from which samples may be taken for example 2 or 3 organisms per aquarium according to the defined biological analysis protocol 50 to 150 fish may for example be in each aquarium. Samples are taken periodically over a predetermined period. The duration is defined according to the number of organisms living in aquaria and the sampling frequency chosen to perform biological measurements.

The aquariums water supply is carried out in open, semi-open or closed system, by the same flow of water supplied by the water inlet unit to be analyzed by means of the output connection feeding each aquarium.

In this example, the control exposure unit 50 comprises two aquariums 51 and 52 supplied with an open, semi-open or closed system by the control water at a predetermined flow rate, this flow rate being the same as the flow rate d. The control aquariums contain the same species of aquatic organisms as the exposure units but the water in which these organisms live is a reference water on which chemical and electrochemical analyzes are also performed.

One exposure unit and the control exposure unit comprise conventional aquariums ie aquariums formed by independent receptacles, each fed with water to be analyzed by a connection with the unit. input 1 and each having an evacuation of this water through an output link. The fish placed in each aquarium are thus isolated from each other which has the advantage of preventing the spread of microbes or viruses contracted within a batch, propagation that would distort the results of biological measurements. In an alternative embodiment illustrated by the diagram of FIG. 6, the control exposure unit 50 may comprise a third aquarium 53 fed in closed system by a standardized water E _N. The aquaria 101, 102, 103 are placed in a tank 111 containing water (tap for example) at a controlled temperature in order to maintain them under the same temperature conditions (water bath).

Live aquatic organisms in aquariums may belong to the same species or to different species, with the aquarium populations of an exposure unit being the same.

In a control aquarium 51, the control organisms are representative of the species or species placed in the aquaria of the exposure unit 100. However, in this aquarium, so-called "positive control" control organisms have been placed. Among these positive control organisms were placed one or more groups of living organisms, each of which received a substance (a heavy metal for example) capable of inducing the maximum increase of biomarkers or bioaccumulation.

In the second aquarium 52 similar groups of living aquatic organisms were placed but without prior induction of bio-markers. These organisms constitute witnesses called negative witnesses.

In the case of the variant embodiment implementing a third sample aquarium 53 in the tank 54 of the unit

50, the same group of living aquatic organisms is placed in this aquarium as in the other two aquariums, but the water is standardized water E _N.

The feed water of the aquarium 53 is subjected to chemical / electrochemical analyzes. For this purpose the unit 2 is coupled by the connection 8 to the water supply of the aquarium FIG. 6. These measurements make it possible to provide an absolute reference. These two populations make it possible to obtain two references, a reference of maximum of induction biomarkers or bioaccumulation and a reference of minimum of induction bio-markers or bioaccumulation. In the given embodiment, the analysis unit 2 comprises a potentiostat 22 to which are connected four electrodes 23. The electrodes 23 are immersed in the water of the various connections 20, 21, 6 and 8, connected to the unit of analysis 2. This unit 2 makes it possible to measure the heavy metal content of the water and to quantify or speciate the metals.

There is a real coupling between biological measurements and chemical / electrochemical measurements since the two groups of measurements are made from water coming from the same water inlet unit.

The exposure unit 100 receives indeed and at the same time the water of the unit 1 as the chemical / electrochemical unit 2 which allows the chemical measurements.

Such coupling also takes place for the biological and chemical / electrochemical measurements relating to the control exposure unit 50.

FIG. 2 illustrates the control system according to a second embodiment corresponding to a version making it possible to discriminate more parameters than the basic module allows.

Indeed, in this embodiment, additional exposure units (two or three), coupled to the basic module, are provided.

In the example illustrated in FIG. 2, two other exposure units referenced 200 and 300 are provided.

Each additional exposure unit 200, 300 comprises, like the exposure unit 100 of the basic module, three aquariums, 201, 202, 203 for the unit 200 and 301, 302, 303 for the unit 300, placed in a tank 211, 311 containing a water 210, and 310 at a controlled temperature. Just as in the basic module this arrangement allows to place the aquariums under the same temperature conditions (about 20 ⁰ C).

Both exposure units 200 and 300 are powered by the same water supply line 3 as the unit 100.

Thus, the measurements made from the population living in these units, are based on water from the same water inlet unit 1. This avoids possible fluctuations that could occur if the conditions of Water and temperature were distinct from one exposure unit to another.

The three exposure units 100, 200, 300 may each be populated with organisms of different species or each of the organisms of the same species. FIG. 3 shows an exemplary embodiment of a water inlet unit 1 that can be used in the embodiment described starting from FIG. 2.

This unit 1 comprises a first storage tank 11 connected to a water inlet pipe 10 E to be controlled and a second storage tank 12 connected to a reference water inlet pipe 16 E _R. Each tank 11 and 12 is connected to the chemical and electrochemical analysis unit 2 respectively via the links 20 and 21. The chemical and electrochemical analysis unit 2 makes it possible to measure the inlet water E ( water quality control) and the reference water used for the control exposure unit.

This input unit 1 further comprises a device 12-15 for diluting the water to be controlled in order to feed the exposure units 100, 200, 300 with a studied water diluted and distributed at a flow rate d. According to two variants, the dilution may be made with the same dilution rate D1 or at different dilution ratios D2, D3.

It will be chosen to use different dilutions to discriminate the metals from ammonia on sewage treatment plant effluents, or the materials in suspension on a high volume water type torrents; And obtain 1/2, 1/4, 1/8 arithmetic dilutions.

We will choose to use the same dilution rate and organisms of the same species in each of the units to discriminate low inducing toxins, requiring a large study population.

FIG. 4 schematizes an embodiment of the system comprising two exposure units 100 and 200, a control exposure unit 50, the analysis unit 2 (a potentiostat and electrodes), coupled to the input unit 1 for the chemical / electrochemical analysis of water. There is also an additional unit 60, in a closed system, not used for biological analyzes but to place a population of aquatic organisms in a reference water E _R under the same temperature conditions in quarantine. that of the aquaria of the exposure units 100, 200 before placing the latter in these units. This system makes it possible, for example by choosing a population of Danios, to perform biological analyzes from exposure biomarkers and effects biomarkers. Among these biomarkers, mention may be made of metallothioneins, total proteins, EROD, catalases, glutathione transferases, and ethyl choline esterases; the exposed and examined populations being of the same species:

1) to detect low inductions or low concentrations, - when the dilution ratios in the units are the same,

2) and to detect the phenomena related to the concentrations (inhibition, competition), - when the dilution ratios in the units are different.

According to another characteristic of the invention, the system is in the form of an independent cabin 500, movable and removable (local technical type distributed under the Premium ® brand for example) so as to be implanted on any type of site near the water to control. This room can be dressed according to the sites on which it will be implanted in different aesthetic forms. In this practical example of embodiment (FIG. 4), the passenger compartment has a length of approximately 6 m and a width of approximately 2.40 m and a height of approximately 1.90 m.

FIG. 5 shows another practical embodiment in which the system comprises four exposure units 100, 200, 300 and 400 and two waiting units 60, 61 for quarantining two populations corresponding to different species. and intended to be placed as and analyzes to one in two units, for example 100, 200 and the other in the other two units 300, 400.

This practical example of realization makes it possible, by choosing for example a population of Danios, a population of mussels (Corbicula) and diluted water with a rate Dl for the units 100, 300 and a rate of D2 for the units 200, 400, of perform biological analyzes and:

To detect: hydrocarbons

- from units 100, 200 to detect: metals

from units 300, 400. Like the embodiment shown in Figure 4, the system is in the form of a cabin 500, independent, movable and removable.

Claims

A water quality control system comprising a base unit (M) comprising: at least one exposure unit (100) of living aquatic organisms known as an exposure unit for biological analyzes;

- a water inlet unit to be analyzed (1) comprising a connection (10) for receiving the water to be analyzed (E) and an outlet connection (3) supplying the exposure unit

(100) which itself comprises an outlet connection (4) discharging this water;

at least one control exposure unit (50) containing control organisms representative of the species or species placed in the exposure unit (100); this control exposure unit (50) comprising a link (6) allowing receiving a reference water (E _R ) and an outlet connection (7) for discharging this water;

and a chemical and electrochemical analysis unit (2) coupled to the output link (3) of the water unit to be analyzed feeding the exposure unit (100), said unit being coupled to the unit control exposure (50) via the link (6) for receiving and analyzing the reference water (E _R );

The basic module (M) thus allowing a coupling under the same conditions of chemical and electrochemical measurements with biological measurements.

2. Control system according to claim 1, characterized in that the chemical / electrochemical analysis unit of the water comprises at least one potentiostat to which are connected one or more electrodes, one of which is connected to at least the inlet of supply of water to the exposure unit.

3. Control system according to claims 1 or 2, characterized in that an exposure unit (100) comprises several aquaria (101, 102, 103), each aquarium containing aquatic organisms of the same species thus constituting a population of organisms from which, for example, 2 or 3 organisms per aquarium can be sampled periodically over a predetermined period of time, depending on the number of organisms and the sampling frequency, in order to perform biological measurements on said predetermined time, these aquatic organisms being placed under the same conditions (in particular temperature, light and oxygenation).

4. Control system according to claim 3 characterized in that the aquariums water supply is carried out in open system, semi-open or closed, by the same flow of water supplied by the water inlet unit to be analyzed (1) by means of the output link (3) feeding each aquarium.

5. Control system according to any one of the preceding claims characterized in that the control exposure unit (50) comprises at least two aquaria (51, 52) placed under the same conditions (in particular temperature, light). and oxygenation).

Control system according to one of the preceding claims, characterized in that the exposure unit (100) and the control exposure unit (50) comprise temperature control means (111, 54 ) water at a constant temperature and that the connections (10, 3, 4, 6, I ₁ ) comprise regulating devices for supply and outlet water flows.

7. Control system according to claim 6, characterized in that the temperature control means are constituted by at least one tank (111; 54) containing water at a given temperature, the aquariums of the unit of exposure (100) and exposure unit control (50) being placed in a tank and thus being in a water bath.

8. Control system according to any one of the preceding claims, characterized in that one exposure unit and the control exposure unit comprise conventional aquaria that is to say aquariums formed by independent receptacles. each fed with water to be analyzed by a connection with the input unit and having an evacuation of this water through an output link.

9. Control system according to any one of the preceding claims, characterized in that the water unit to be controlled (1) comprises several dilution tanks

(13, 14, 15) of this water with the reference water E _R so as to obtain at the outlet of each dilution tank, a water to be analyzed having a given dilution ratio which may be different from a tank to the other, the system further comprising one or more additional exposure units (200, 300), the exposure units (100, 200, 300) being fed by these bins so as to have a dilution range.

10. Control system according to any one of the preceding claims, characterized in that in the case where the base module (M) is coupled to one or more exposure units (200, 300), at least two exposure units contain either water with the same dilution ratio and organisms of different species, different dilution rates and organisms of the same species, or identical dilution rates and organisms of the same species .

11. Control system according to any one of the preceding claims, characterized in that the control exposure unit (50) comprises an aquarium (51) containing positive controls consisting of aquatic organisms of the same species as in the units. of exposure, induced by a first toxic substance, and an aquarium (52) containing negative controls consisting of aquatic organisms of same species as positive controls but without induction by a toxic substance.

12. Control system according to any one of the preceding claims, characterized in that the system further comprises one or more quarantine units (60, 61), in which the various organisms are placed before being placed in the exposure units used for the measurements.

13. Control system according to any one of the preceding claims, characterized in that it is in the form of a modular cabin (500), removable and movable containing the base module.

14. Control system according to claims 10, 11, 12 and 13, characterized in that it is in the form of a modular cabin containing the base module and also the additional units (200, 300, 60, 61).

15. Control system according to any one of the preceding claims, characterized in that an exposure unit (100, 200, 300) comprises at least three aquariums.