Nonlinear and interactive effects in the sorption of hydrophobic organic chemicals by sediments

Abstract

AbstractLong‐term experiments were done in order to investigate nonlinear isotherms and interactive effects in the sorption of hydrophobic organic chemicals (HOCs) by sediments. In the isotherm experiments, it was demonstrated that the isotherms for all HOCs tested were linear as long as the mass of the sorbed HOC was small by comparison with the mass of organic carbon in the sediments; for larger sorbed HOC concentrations, the isotherms were nonlinear. Sorption experiments also were done with hexachlorobenzene (HCB)–octanol, HCB–ethanol, octanol–ethanol, and HOC–methanol mixtures in water and sediments. Interactive effects were observed and can be described in terms of the partitioning of the primary HOC between the cosolvent, water, and sediments.