New Oslo Airport Gardermoen. Biodegradation of the de-icing fluids Kilfrost DF and Clearway 1 in a soil profile

Abstract

The fate of the de-icing fluids Kilfrost DF (propylene glycol) and Clearway 1 (K-acetate) has been studied in soil lysimeters incubated in the laboratory. Experiments were carried out by 2-4°C and 12-14°C and the water quality of percolated water followed for 284 days. The results show that both chemicals are biodegraded efficiently when oxygen is available by a load of 20-50 mg/l mearsured as DOC, both at high and low temperature regimes and by a hydraulic retention time of 20 days in the 0-1 m depth interval. By higher loads anoxic conditions can develop. The biodegradation of acetate was inhibited by anoxic conditions, while propylene glycol was only partially degraded, possibly to intermediate products. When measures are taken to areate and fertilize the topsoil the capacity for biodegradation is likely to increase somewhat.