[Equipment to find odour compounds, produced by bacteria in drinking water. I. Comparison of a bacteria produced odour compound with a chemical reference substance and a simple method for getting and concentrating biogenic odour compounds (author's transl)].
An increase in using surface water and bank filtration processes as raw water for drinking water production sometimes gave rise to problems of bad taste and odour. Some of these odourous compounds may be produced by bacteria, especially Streptomyces species. They are able to pass active carbon filters and therefore are a problem as well in raw water as in treated water. Biogenic odourous compounds often are soluble in water, that means they are present without being fixed to the bacteria cell. Human nose is able to percieve even dilutions of about 10(-9). If a bacterial produced substance is compared with an equal smelling chemical substance such as Isoborneol, also diltuions of 10(-9) may be smelt. Gas-chromatography only detects concentrations up to 10(-5), so the nose is much more efficient.