SORPTION OF TYPICAL PAHS ON MANGROVE SEDIMENT AND THEIR INFLUENCING FACTORS

Batch isotherm experiments were performed to study the sorption characteristics of typical polycyclic aromatic hydrocarbons(PAHs),naphthalene,anthracene and benzo[a]pyrene on mangrove sediment from Jiulong River estuary.The effects of water temperature,salinity and sediment aggregates with different sizes on the sorption of the three PAHs were investigated.The results demonstrated that the sorption of the three PAHs in the mangrove sediment was a two-step process,including a rapid sorption process and then a slow sorption process.The sorption process can be well described by Freundlich model,and the sorption of the three PAHs on sediment was nonlinear.The sorption capacities of the PAHs on the sediment were in the order of benzo[a]pyreneanthracenenaphthalene.The sorption capacities of the three PAHs on sediment decreased with increasing temperature,but increased with salinity.The sorption capacities of PAHs on sediment aggregates with different sizes were in the order of 0.063—0.25( 0.063)0.25—1.0(1.0) mm,and it was due to the difference of black carbon content in sediment aggregates.