ABSTRACT
Surfactants and contaminants pass into soil through products and waste flow. The input pathways of contaminants are largely known [1] and are not discussed here. Possible surfactant sources are as follows:
Agricultural application of pesticides and fertilizers Agricultural sewage sludge Sewage sprinkling on irrigation fields and irrigation with river water containing
surfactants 39
Households not connected to sewage treatment plants Defective sewers Sewage plant overflows caused by heavy rain events Soil remediation Surfactant-loaded layer silicates as barrier layer materials in landfill engineering
and as carriers for pesticides Tertiary oil recovery
Although these input pathways have long been known, studies on the behavior of surfactants in soils, for example their mobility, degradability, and damaging effects, are available to only a limited extent. This might be attributed to the fact that the quantities passed into the soil are regarded as small and ecotoxicologically harmless and that the apparently satisfactory degradation rates in test sys tems and in the aquatic ecosystem are directly extrapolated or transferred to the conditions in soil. Several facts indicate, however, that the behavior of surfac tants in soil demonstrates numerous ambiguities.
