| Abstract: | Sodium dodecylsulfate solutions contaminated with polycyclic aromatic hydrocarbons (PAH), e.g. pyrene, were purified by addition of calcium or barium salt solution and precipitation of the corresponding calcium or barium dodecylsulfate. The precipitates were cleaned up using several organic solvents. Regeneration of sodium dodecylsulfate from the calcium dodecylsulfate precipitate was possible by solving the substance in an ethanol/water mixture (1:1) and precipitation of calcium hydroxide using sodium hydroxide as a precipitating agent. It was shown, that the calcium dodecylsulfate can be used directly as a tenside in a hot water solution or in an ethanol/water mixture. An extraction procedure could be developed, to remove the PAH contaminations quantitatively from the tenside solutions and concentrate them to small quantities by distillation of the organic solvents. It was demonstrated, that closed cycles of reagents in low need of energy are possible. The procedure was tested at a perylene contaminated kaolin sample. |
