System for biological testing at water supply stations in St. Petersburg

Currently surface sources including those used for public drinking water supply are subjected to continuous human-induced impact, there is also a risk of sudden accidental pollution.

In order to ensure safety of water supply of Saint Petersburg population from accidental (emergency) or intended (an act of terrorism) pollution with toxic substances on water intake facilities at the Neva River, these water supply stations facilities are equipped with water quality production biological monitoring stations (hereinafter referred to as WQPMS). WQPMS provides for measurement of the cardiac rhythm of indigenous crayfish and analysis of fish behavior. If the water taken from the Neva has toxic substances, the crayfish will have intensified heartbeat, and the fish will rapidly change their behavior.

Components installed in the solution

The operation of WQPBMS is organized by the principle of continuous automatic bioindication of the quality of water as a habitat, on the basis of the method of variational pulsometry of the indigenous crayfish and fish.

WQPBMS includes:

  • aquariums to contain indigenous noble crayfish with a system for registration and analysis of the cardiac rhythm of animals in real time,
  • an aquarium to contain fish which are monitored 24/7 with transmission of a signal image to the Control station of the personnel on duty of the water supply stations.

Operational mode

Information on the status of the crayfish organisms is displayed on the recorder using a thin optic fiber, then the initial signal is transformed and the obtained digital series processed automatically by the method of variational pulsometry. The processed signal is received by the monitor of the computer of the personnel on duty with this or other color signal.

The personnel on duty of controlling subdivisions of water supply stations continuously controls the current status of the presence or absence of rapid and significant changes in the level of toxicological hazard of the water of the source received by the water intake facilities of water supply stations. Control is performed on the basis of the results of automatic processing and real time analysis of the dynamics of changes in the characteristics of the cardiac activity of crayfish and the characteristics of mobility of fish used as test organisms measured and analyzed by WQPBMS. At that, the real dynamics of changes in water, air temperature, and the noise intensity (biologically significant factors the uncontrolled change in which will lead to the same changes, just as a considerable additional “shock” contamination of water) are also taken into account. For illustrative purposes, both individual (by specific test organisms) and integral quality indicators of the change in the degree of contamination are formed (“streetlight” system: red is a sign of accident risk, yellow is presence of signs of threat, blue is a sign of limitations in the operation of technical systems, and green is a sign of absence of the above manifestations).

Production biological water quality monitoring stations are located in engine rooms of elevation 1 at 7 water supply stations of SUE "Vodokanal of St. Petersburg" that operates the system of water treatment of Saint Petersburg. Currently there a 9 installed biological monitoring stations.

Changes in the cardiac activity of crayfish and activity of fishes act as a signal for starting the system of biotesting at water intake facilities of the water treatment plant. These changes signify the existence of toxic substances in the water. Throughout the operation of the system, there have not been any cases of the system being triggered.

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