Quantitative determination of perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA) compounds in surface waters in ergene waterbasin and evaluation of the treatability of these compounds

It is necessary to discharge treated domestic or industrial wastewater into receiving water environment by eliminating any adverse effect arising from persistent organic pollutants of which its concentration have been increasing in water sources. Stockholm Convention is a global treaty on Persistent Organic Pollutants (POPs), that was signed on 23 May 2001 and entered into force 17th May 2004. Turkey became a part of this convention on 12 January 2010. In our country PFOS and its derivatives have been identified as specified pollutants for surface water resources within the context of "Surface Water Quality Management Regulation". There are approximately 1500 industrial plants and enterprises in the Ergene Basin, and nearly 700 of these facilities are water-consuming and wastewater-generating. These PFOS and PFOA pollutants, which are found in wastewater, especially in textile wastewater, are expected to be present in surface water resources in Çorlu and Çerkezköy Region. There is no comprehensive study on the concentrations of these compounds in water environments in the Ergene Basin. In this project, samples were taken from surface waters (Çorlu and Ergene Rivers) in the Ergene Basin, which was heavily polluted by industrial activities, in winter, spring and summer seasons, twice in each season and PFOA/PFOS concentrations were determined. BS ISO 25101-2009 extraction method and LC-MS/MS were used to determine the concentration of these pollutants. Synthetic samples were prepared for the removal studies of these chemicals and for that Activated Carbon Adsorption, Sulfate Radical Based Oxidation and Nanofiltration methods were performed. The results of the study revealed that powder activated carbon for the removal of these pollutants yielded better results and the removal efficiencies were above 90%. The removal efficiencies with nanofiltration ranged between 50-90% using different membranes. At the end of the oxidation with sulphate radical at different persulphate doses and different temperatures studies, it was found that PFOS pollutant could not be removed at all, PFOA pollutant was removed by 50% after 2 hours of oxidation time and the yield reached 90% after 5 hours.