Characterization of the compounds involved in the problems of taste and odour in the water of Sidi Mohamed Ben Abdellah dam (Morocco)

This work deals with the characterization of the organic compounds involved in the alteration of the taste and odour of the water of sidi mohamed ben abdellah (smba) dam,which is considered as the main source of the production of drinking water in morocco. in late summer 2005,consumers receiving treated water from the smba dam complained about the deterioration of organoleptic properties of their drinking water. examination of physico-chemical parameters of water showed that this dam is mesotrophic with a tendency to be eutrophic. afterwards analysis of the volatile organic compounds of water has been undertaken; for this purpose,water samples were collected at different depths of the smba dam and were extracted by closed-loop stripping analysis. the volatile compounds obtained were analyzed by gas chromatography/mass spectrometry. a total of sixty-three compounds from different chemical classes were separated and identified. geosmin and 2-methylisoborneol were not found among the identified substances. however,other compounds with odorous properties have been detected. these are terpenes such as borneol,limonene and α-pinene or benzenic compounds such as benzaldehyde,toluene and mesitylene. these substances have biological or chemical origin. these results suggest that the deterioration of the organoleptic properties of the smba dam water is not due to a single compound but rather a mixture of odorants.