Werner Stumm

From 1970 until 1992 he was head of the Swiss Federal Water Resources Centre EAWAG.

During the early part of his career he was influenced by the ideas of Lars Gunnar Sillén and Robert Garrels regarding aqueous chemical equilibria.

He developed models where the ideas by Sillén regarding equilibria were combined with improved descriptions of kinetically controlled reactions (i.e. slow reactions that do not reach equilibrium, e.g. weathering).

He in particular made contributions to the knowledge of the reactions at the interface of minerals and water.

In his more than 200 scientific articles he showed, among other things, that the rate by which a mineral weathers depends on the surface charge, which in turn is controlled by factors such as pH and the chemical composition of aqueous solutions.