Die Wasserversorgung von Düsseldorf: Ein Beispiel für den sinnvollen Einsatz von Korrosionsinhibitoren

Corrosion of unprotected cast-iron pipes in drinking water networks can lead to the deterioration of the drinking water quality because of red water, which leads in practice often to consumers complaints. The water works Dusseldorf committed themselves for the quality of their drinking water since years. Based on investigations carried out in 1982 a corrosion inhibitor is used since twenty years. Because of the water quality which became much better with respect to corrosion processes over the last years, it was investigated, if concentration and composition of the inhibitor in use can be further optimised. Therefore, corrosion experiments with unprotected steel pipes were carried out, which demonstrated, that less phosphate could be used.