Μελέτη του γίγνεσθαι των γραμμικών αλκυλοβενζοσουλφονικών επιφανειοδρασικών (Las) στις μονάδες επεξεργασίας λυμάτων και στο θαλάσσιο περιβάλλον

The Linear Alkylbenzene Sulfonates (LAS) comprise a class of anionic surfactants that are the key active ingredients in laundry detergents which, after use, are discharged into the environment in wastewater. In addition to LAS, Linear Alkylbenzenes (LAB) are also identified in the environment as precursor compounds to LAS and by-products of latter. In the present paper we examine the presence of such substances in the sewage of the town of Heraklion and their biodegradation during the various stages of processing in the Sewage Treatment Plant of Heraklion. To this end we took samples from the four basic stages of processing at Sewage Treatment Plant of Heraklion, i.e. inflow, primary sedimentation tank, secondary sedimentation tank and chlorination tank (outflow). Also, since the processed sewage is discharged in the broader marine zone of Heraklion via an underwater duct, we also investigated their presence in the aquatic environment of the bay of Heraklion. Consequently, in order to determine the concentration of LAS and LAB, we received eight samples of seawater and four samples of surface sediments from locations near the effluents of Sewage Treatment Plant of Heraklion and the Biological Treatment Facility of the Industrial Area of Heraklion. For LAS determination we utilized the High Performance Liquid Chromatography (HPLC). This method is considered most suitable and highly sensitive for the exact determination of LAS concentration in varied environmental situations. The corresponding method for the determination of LAB concentration in various environmental situations is the combined method of Gas Chromatography / Mass Spectroscopy (GC/MS)