Non biodegradable and weakly adsorbing substances in the river Elbe

The quality of the river Elbe in East Germany has been investigated in a research project subsidized by the German minstry of research and technology, iwth respect to drinking water quality and treatment using laboratory methods similar to the treatment processes in waterworks. The experiments included analysis of sum- and group-parameters before and after biological degradation and a study of adsorption on activated carbon. Comparing these results with data already published from the river Rhine in West Germany, the water of the river Elbe showed approximately double the concentration of dissolved organic carbon (DOC), absorbable organic halogen (AOX) and ion-pair-extractable organic sulphur (IOS). Mathematical models have been used to obtain further information from these measurements about the origin of the organic substances in the river Elbe. As a consequence, an important part of the relatively high DOC-concentration in the Elbe-river is due to natural humic substances. Therefore the operation of better waste water treatment plants along the elbe-river might reduce the concentration of organic halogen and sulphur substances in particular, whereas the concentration of DOC will decrease only slightly in the future. (orig.)