Effects of Surfactants on the Aggregate Stability of Soils

Abstract

In spite of surfactants being widely used and their toxic effects on living organisms has been well known we have only little information about how they influence the different properties of soils. However, surfactants may cause changes in the physical, chemical and microbiological parameters of soils. They can modify the structure of soils through the aggregate stability, as well as the fertility indirectly. In our study we investigated the effects of cetilpyridinium chloride (a cationic surfactant) on aggregate stability of eight different soil horizons. Aggregate stability measurements were performed based on the wet sieving method immediately following various pre-treatment procedures. There were compared the SAS values (percentages of the stable aggregates) of soils pre-treated with distilled water or surfactant solutions of various concentrations. It was found that the aggregate stability of soils increases to the highest level in case of the soil samples treated with moderate amounts of surfactant which form nearly monomolecular adsorptive layer on soil surfaces.