Sorption of Chelating Agents (HEDP and NTA) Onto Mineral Phases and Sediments in Aquatic Model Systems. Part I: Sorption at Clay Minerals.

The fate of organic chelating agents in the aquatic environment may be mostly determined by reactions, which regulate the distribution of chemicals between the solid and liquid phase. Especially adsorption/desorption processes are important for the adjustment of the distribution equilibrium. To assess the influence of such processes on the environmental fate of the phosphate substituting chelates 1-hydroxyethane-1,1-diphosphonic acid (HEDP) and nitrilotriacetic acid (NTA), adsorption studies were carried out in aquatic model systems, containing different adsorbents like clay minerals, sediments and sewage sludges