Adsorption of some monohydroxybenzene derivatives by soils

Natural soil materials react with derivatives of benzene in water under saturated conditions slowly, with equilibration times of up to 5 days. The Freundlich isotherm equation fits best those water-phenol-soil systems in which few soil properties dominate. For the fine-textured B horizon soils used in this experiment, percentage iron oxides and solution pH were found to be the most important factors related to adsorption of these phenols by soils. Molokai clay had the highest adsorption rate of simple phenols. Slightly soluble phenols, such as dimethyl and dichloro phenols, seem to be able to react better with soils than the more readily soluble phenols, such as cresols, phenol, and p-nitrophenol. In comparing Hammett (σ) and hydrophobic (π) constants with the laboratory results, we found that a high degree of correlation seems to exist between them and the behavior of these organics in soils.