| Abstract: | The increasing nitrate concentrations in the ground water and drinking water which are caused by intensified fertilizing lead to the risk of methaemoglobinaemia of babies and increase the cancerogenic, teratogenic and mutagenic risk for the total population. In the drinking water conditioning the nitrate concentration can be reduced by different techniques. By ion exchange first the SO4-ions and then the nitrate-ions are removed. Very favourable is the exchange for HCO and the regeneration by means of carbon dioxide and CaCO3, for which a mass balance of substances is given. With 0.55 DM/m3 also the reverse osmosis in a mixture with raw water is practicable and also electrodialysis can be applied, whereas the biological techniques of the heterotrophic or autotrophic denitrification still include unsolved technological problems due to the necessity of an organic substrate or of H2. The special features of each of these techniques and the hygienic and also the corrosion-chemical consequences are indicated. |
