Laboratory methodology to approach soil water transport in the presence of surfactants

Surfactants are widespread in soil due to waste-water irrigation, application of sludges and agricultural activities. Because of their amphiphilic nature, they have the potential to influence water flow and retention properties of soils. The infiltration rates of surfactants applied at concentrations above the critical micelle concentration were measured on laboratory vertical columns of soil. Different surfactants were tested: Triton X-100, Aerosol 22 and hexadecyl trimethyl ammonium bromide (HDTMA). The laboratory experimental design allowed an evaluation of the potential changes induced by the presence of surfactants on water flow. Soil sorptivity was slightly affected and saturated conductivity was reduced by HDTMA and Aerosol 22.