Sorption behaviour of benzyl butyl phthalate on marine sediments: Equilibrium assessments, effects of organic carbon content, temperature and salinity

Benzyl butyl phthalate (BBP) is an endocrine-disrupting chemical, and its sorption behaviour on marine sediments was investigated. BBP sorption on the sediments was a rapid process, which could reach equilibrium in 6 h. The sorption equilibrium results could be well described by a linear isotherm. The BBP partition coefficient, Kd, varied from 7.16 to 12.54 L/g in approximately proportion to the organic content of the sediments. After H2O2 oxidation for removing the organic material from the sediments, the Kd values were reduced by more than 70%, but the organic normalised partition coefficient averaged 2165 L/g for the H2O2-treated sediments, which was more than three times of 598 L/g for the raw sediments. The sorption of BBP on the sediments increased with a decrease in temperature and an increase in salinity. A salting constant of 1.14 L/mol was obtained for BBP in artificial seawater. These research findings are of importance to an assessment of the fate and transport of BBP and other similar endocrine-disrupting chemicals (EDCs) in seawater–sediment systems.