Sorption of linear alkylbenzenesulfonates (LAS) on marine sediment

The sorption of a commercial-grade linear alkylbenzenesulfonate (LAS) and of its constituent homologous compounds was characterized in marine sediments from the Bay of Cadiz (southwestern Spain). Experimental data were fitted to a Freundlich model. The sorption coefficient K ranged from 96 for the homologue C10-LAS to 1112 for the homologue C13-LAS, with sorption expressed as μgg−1 LAS of sediment and equilibrium LAS concentration as mgl−1. LAS sorption on marine sediment was found to be an irreversible process. K increased substantially with increasing salinity. The relation was linear for the homologue C11-LAS, with a threefold increase in the value of K as salinity increased from 0 to 75.