Alternative Treatment of De-icing Fluids from Airports

Abstract

In order to maintain safe air-traffic conditions during landing and take-off operations in airports at temperatures below freezing, deicing chemicals are used on the airplanes as well as on the runways. In most cases low molecular weight alcohols are used for deicing the airplanes, whereas for the runways alcoholic compounds are often combined with urea as a non-corrosive deicer. Accordingly, the run-off water from airplanes and runways contains high concentrations of the aforementioned chemicals. These in turn, cause tremendous heterotrophic growth and high NH ⁺₄ -concentrations from the hydrolysis of ureà in the receiving waters during winter time. At the Zürich airport, different ways of treating the deicing fluids were studied during the winter periods of 1985/86 and 1986/87. The purpose was to obtain alternative solutions for the removal of the organic substances and of urea and ammonia and to quantify the respective removal potentials.