Sorption behavior of non-polar hydrophobic organic chemicals on soils, sediments of Bangladesh

This study focus on the determination of sorption parameters for frequently used organic compounds (contaminants and pesticides) to see the effect in Bangladesh top soils and sediments. For a variety of organic compounds (TCE, 1,2DCB, Phenanthrene and Heptachlor) batch and column experiments were carried out on different natural geosorbents (Deltaic, Floodplain, Residuum soils, aquifer sediments and pear). In general, the soils show almost linear sorption isotherms and due to the small grain sizes fast sorption kinetics. For these samples the measured organic carbon normalized distribution coefficients (Koc) were in close agreement to calculated values based on the Karickhoff equation. For the pear and deltaic soil samples, a non-linear Freundlich type sorption isotherm was fitted to the data. Slightly higher Koc-values indicate that type and origin of organic matter varies within the observed geosorbents.