Das Projekt "Abiotische Umwandlung anthropogener organischer Zusammensetzungen in Boeden: Kinetik der oberflaechen-induzierten Hydrolyse von Phosphorestern bei Vorliegen ausgewaehlter Ton- und Metallhydroxid-Minerale" wird vom Umweltbundesamt gefördert und von Haus der Technik e.V. durchgeführt. Soils and aquifers are increasingly polluted by anthropogenic organic substances. The interaction with the solid matrix plays an important part in the fate of the chemicals. The importance of abiotic transformations at the solid-liquid interface, the most prominent of which are hydrolysis and redox reactions, has so far been underestimated. The objective of this project was to study the kinetics of heterogeneous hydrolysis of pesticides in the presence of oxides and clay minerals. Reactions were studied under batch as well as steady-state conditions. For the analysis of the data the numerical steady-state reaction model STEADYQL was combined with a curve-fitting routine on the basis of the Levenberg-Marquardt algorithm and implemented under the name Steady Fit. The program allows the simultaneous determination of kinetic and equilibrium reaction constants from experimental data obtained under steady-state conditions. The experimental system was successfully tested using the hydrolysis of phenylpicolinate by titan dioxide as a test system. Finally the hydrolysis of the carbamate pesticide carbosulfan was investigated in suspensions with montmorillonite, titan dioxide, manganese dioxide and the clay-silt fractions of two acidic soils. Montomorillonite had the stongest effect, acceleration hydrolysis up to several orders of magnitude in the neutral pH range in which homogeneous hydrolysis was slowest.