The invention concerns a method for treatment of solid and fluid materials contaminated by at least predominantly lipophilic harmful substances, in particular hydrocarbons and the like, especially for oil-infested grounds and waters, as well as suitable systems and emulsifier substances for carrying out the method. The contaminated materials, for microdispersed emulsifying of the harmful substances, is intimately mixed with at least one emulsifying substance as well as possibly with water. Subsequently, the emulsion is separated from the material while adding water, and preferentially biologically decomposed.
