EXTRACTION BEHAVIOR OF HEAVY-METALS

Depending on the type of the head group (anionic, cationic and nonioni c) as well as the structure the adsorption layers of surfactants on th e liquid/liquid interface have an essential influence on the extractio n behavior and the mass transfer of heavy metals (Cd, Zn, Pb, Cr). By choosing the right type and concentration of surfactant it should ther efore be possible to accelerate the mass transfer thus improving the e xtraction rate (e.g, sodium dodecylsulfonate), or even to prevent a ma ss transfer almost completely (e.g. i-octylphenyl ethoxylate). The pur pose of this paper is to control the selectivity of the mass-transfer accompanied by reaction beyond fluid interfaces with the help of surfa ctants as well as to clarify the effective mechanisms.