De-icing a plane is essential for passenger safety. Required when temperatures get close to zero, de-icing is an almost daily operation at Genève Aéroport during the winter months. How does it work? How are the residues of the de-icing products treated? Here is all you need to know.
De-icing is an essential part of preparing an aircraft for departure. Accumulations of frost, ice and snow on the wings and tail can compromise the plane’s take-off and flight. At Genève Aéroport, in 2019, 3'236 aircraft (scheduled and charter flights) underwent the operation, while in January 2020 alone, 809 aircraft were de-iced.
The airport has a fleet of 20 de-icers. They first spray a mixture of hot water and glycol over the aircraft to remove snow and ice. Another glycol-based fluid is then used to prevent frost from reforming. In 2019, 849 m3 of de-icing products were used on aircraft.
The aircraft then has a « protection time » in which it needs to reach the runway for take-off. The aim is that the aircraft take off quickly so that the operation need not be repeated. To do so, de-icing must be, for example, carefully synchronised with clearing the snow from the runway.
Treating the residues of de-icing
What happens to the residues of the glycol-based fluid when they hit the ground? A road sweeper removes and collects them from where the plane was de-iced. Since early 2018, the residues are then treated in the bioreactors at the wastewater treatment plant (WWTP) in Aïre and turned into biogas. In 2019, 635 m3 of de-icing product produced almost 180'000 m3 of biogas.
Moreover, since January 2019, water polluted by de-icing products ending up on the runway and outside the gates is recovered by a network of collectors. It is then stored in a retention basin at the end of the runway, before being sent to the same water treatment plant.