Water regime change of surfactant polluted soils

Abstract

Studies were made on the adsorption of a cationic surfactant, hexadecylpyridinium-chloride (CPC), on various soils and sediments. The aim was to determine how modify the adsorbed surfactant the soil physical characteristics, mainly water regime. Water retention were measured, pore size distribution curves were derived from water retention curves, modal suction, total porosity and rate of different pores (macro-, meso-, micro-, ultramicro- and cryptopores) were evaluated. Due to CPC treatment, samples became hydrophobic. Rate of cryptopores declined at all surfactant treated samples, while rate of micropores were raised most of the samples. Except for two samples total porosity was decreased, as well. Kind of these changes can depend on differences in particle size distribution, calcium carbonate content, aggregate stability, quantity and quality of clay minerals. As pore size changes, amount of retained water also changes.