To date, the effect of salinity on the sorption process of organic pollutants on solid sorbents has been studied considering that sorption is a linear process that depends on the fraction of organic carbon. Studies of the last decade have proven that the sorption of organics in the environment is not necessarily a linear process. For sediments and soils with particulate carbonaceous contaminants, such as soot or coal particles, organic contaminant isotherms with a large non-linearity have been observed. Preliminary studies have shown that indeed salinity affects sorption depending on the mechanism observed for each sorbent species. Otherwise, sorption is affected by salinity, when it takes place on the surface of the sorbent, and otherwise in the pores inside the sorbent. The postgraduate research includes an experimental study of the equilibrium and kinetics of the sorption of an organic pollutant (phenanthrene) on various sorbents from seawater. The sorbents include carbonaceous particles and heterogeneous materials, such as charcoal, lignite and marine sediments from the area of ​​Aliveri, Lavrio and the Saronic Gulf (Loutropyrgos) that have been contaminated by the above carbonaceous particles.