Process and apparatus for the detection of toxicity in surface waters as well as drinking water and industrial water

DETAILED DESCRIPTION We claim: 1.
A process for the detection of toxicity in water, comprising the steps of: stimulating a water sample containing a toxicity-sensitive bioorganism by means of light having at least one predetermined wavelength; measuring the intensity of prompt fluorescence in the light-stimulated water sample containing said bioorganism; providing an output value corresponding to the measured intensity of prompt fluorescence; measuring the intensity of delayed fluorescence of the light-stimulated water containing said bioorganism synchronously with said measuring of prompt fluorescence intensity; providing an output value corresponding to the measured intensity of delayed fluorescence; correlating said output value corresponding to the measured intensity of prompt fluorescence with said value corresponding to the measured intensity of delayed fluorescence to obtain a correlated sample value; and providing an indication of said correlated sample value compared with a correlated sample value obtained from a non-contaminated sample, as a measure of the toxicity level of said light-stimulated water.
2.
The process of claim 1 wherein said correlating step includes measuring within a predetermined time window starting from the end of influence of the stimulating light for the retarded fluorescence on the sample, this time window defined between 0.
1 to 500 seconds after the end of said stimulating light for the retarded fluorescence.
3.
The process of claim 1 wherein the toxicity-sensitive bioorganism is selected from the group consisting of planktons, phytoplanktons, bacteria and dinoflagellates.
4.
The process of claim 1 wherein the light-stimulating step includes using light having at least two predetermined wavelengths.
5.
The process of claim 1 wherein said light-stimulating step includes using light having a wavelength of 440 nm for stimulating prompt and retarded fluorescences.
6.
The process of claim 1 wherein said light-stimulating step includes using light having a wavelength range between 660 nm to 685 nm for stimulating prompt and retarded fluorescences