Surfactants, natural as naphthenic acid derivatives, or additives such as those of the glycol-type, anti-icing, static dissipators, corrosion inhibitors, added intentionally or picked up in multiproduct pipelines, impair the operation of filters/separators, and tend to retain water droplets in suspension. Microbiological growth has been suspected to give rise to similar troubles.
On the other hand the solubility of water (ppm vol/vol) in wide cut turbo fuel is greater than in kerosine type, approximately as follows:
oC kero[→]wide cut
0 28[→] 45
20 45[→] 82
40 82[→]140
Clearly, water solubility drops with a decrease in temperature. At the low temperatures encountered in flight, much of it will form crystals that remain suspended in the fuel due to the aircraft movement, some will settle out.
Dried fuel will reach a water equilibrium in a matter of hours when exposed to the atmosphere. Thus, it is considered impractical to attempt to remove dissolved water by use of refrigeration or dessicants.