Fig. 5. The variation of free energy change (G) with temperature for sorption of fluorene, phenanthrene, and pyrene on the geosorbents: , San Diego sediment (SD); , Guanella Pass peat (GP); , Allivar soil (AS); •, Poinsett soil (PS); and x, Hetland soil (HS). The open labels correspond to the extracted samples. The error bars represent the absolute standard deviations.