EXPERIMENTAL PROBLEMS IN DETERMINING SORPTION COEFFICIENTS OF ORGANIC-CHEMICALS - AN EXAMPLE FOR CHLOROBENZENES

Sorption of five chlorinated benzenes have been determined for a lake sediment. Sorption isotherms are linear over the tested aqueous concen trations ranges (three orders of magnitude), which supports the sorpti on partitioning model. Sorption coefficients of the chlorobenzenes are compared to the results of other sorption studies on the basis of sor ption coefficient ratios and are consistent with literature data. In t his study emphasis is on the experimental problems in determining sorp tion coefficients. Sediment extractions and experimental conditions su ch as equilibrium period, water-sediment separation and water/sediment ratio may influence sorption results. These possible experimental art efacts are investigated in this study in order to have better insight in the influence of the experimental artefacts and consequently in the spread of the experimental sorption coefficients.