Fluorinated surfactants: synthesis, properties, effluent treatment

Fluorinated surfactants and synthetic fire fighting foams are presented, The fluorinated part of those surfactants can be obtained industrially either by electrofluorination or by telomerization. The fact that fluorine atoms are present in a surfactant molecule modifies its behaviour compared to classical surfactants. It gives to the molecule outstanding chemical and thermal stabilities. Fluorine also produces in these surfactants very low surface tension in aqueous solution even when used at reduced concentrations. For those reasons, it is shown that fluorinated surfactants are particularly adapted to the formulation of film forming fire fighting foams in which they are associated to classical hydrocarbon surfactants. Finally, a way of removing the mean components of a tire fighting foam from the waste water resulting from fire fighting training or a real application is presented. (C) 2002 Elsevier Science B.V All rights reserved.