ABSTRACT
I. INTRODUCTION In nearly all processes in which water plays a role, disturbances by metal ions dissolved in the water pose a central problem. Drinking water contains different fractions of dissolved metal ions, depending on its origin. The magnesium and calcium ion content governs water hardness: disturbances can occur as a result of the catalytic influence of heavy metal ions and precipitates from relatively insol uble metal salts can impair the different effects of detergents and cleaning agents. Complexing or chelating agents largely prevent these undesirable reactions.
