FLOTATION AS A PROCESS STEP IN THE TREATMENT OF SOILS CONTAMINATED WITH MINERAL-OILS

The cleaning of mineral oil contaminated soils by means of soil washin g presently is not economically feasible in case of soils with high co ntents of fine particles (i.e. clay and silt). An additional notation step within a soil washing plant can be helpful to clean these soils. The effects of pH value and notation agent were investigated in a labo ratory notation cell. Pilot-scale notation experiments were carried ou t in a pneumatic notation plant with two soils contaminated with diffe rent concentrations of mineral oils. It was found that best results we re gained at pH-values below 3, and that the cleaning result may be in fluenced by adding notation reagents. Integrating a notation step into a soil washing plant can reduce the residual oil content in the clean ed soil fraction significantly. An example demonstrates that the integ ration of a notation step may improve the efficiency of the convention al soil washing process. It may thus extend the applicability of soil washing to the remediation of soils with high content of fine particle s.