De-icing - what's used?

[Pax-man]

Just curious as what's the solution used for de-icing?

Guess it's probably chemical and not organic - do airports that use it in any sizeable quantity have some sort of closed drainage system to prevent any potential pollution problems?

[Prince Buster]

P-man,

Most (not all) have drains at either stand if de-icing on stand is performed or drain at any remote de-icing location. Don't know the environmental regulations but I'm sure there are heaps of thoose and that every airport follows it. I hope!!:hmm:

[TheOddOne]

Aircraft ant-icing these days uses a monopropolyne glycol with a thickening agent to depress the freezing point of deposits of water or frost on aircraft. It can also be used to remove snow and ice. It is biodegradable but only over a period of time, so that it does present a considerable bio-hazard.

Most aerodromes in the UK now use a potassium acetate liquid to depress the freezing point of water deposits on runways, taxiways, stands and airside roads. Salt cannot be used airside because it is very corrosive in contact with aircraft. Potassium acetate is also a bio-hazard but breaks down much more quickly, therefore being considered much more environmentally-friendly than the formerly used ethelyne glycol products. One disadvantage with potassium acetate is that it is very poor at attacking ice and already-fallen snow. There is a solid variant available in prill form, which is more effective for de-icing (if you've missed the opportunity to ant-ice), especially when pre-wetted with liquid potassium acetate.

At Gatwick, the drainage system from all stands and most of the other airside areas feeds into a large pond, where run-off can be storerd until the biological index has fallen to a value such that the Environment Agency will accept the water into the local water-course (the River Mole in our case). This can be a problem when we have a large amount of ant-icing taking place but little precipitation to dilute it.

There is a programme of sweeping up excess aircraft ant-icing fluid from stands. This serves the dual benefit of enabling the fluid to be re-used for another purpose and reduces the slipping hazard which the fluid sometimes presents.

TheOddOne