Abstract:In the present study, accumulation and elimination processes of two metals(Cu,Cd) in Crassostrea plicatula were simulated by using the two-conpartment kinetic model. A semi-static system was maintained throughout 36d exposure period in different concentrations of heavy metals. Kinetic parameters of bio-concentration were obtained from the two-conpartment kinetic model by nonlinear curve fitting for the two periods respectively, including uptake rate constant(k1), elimination rate constant(k2), bioconcentration factor(BCF), and biological half-life(B1/2). It was found that the metal concentration and elimination were well fittted to the two-conpartment model by using the goodness-of-fit test. The results indicated that: (1) In the uptake period, the uptake rate constant and bioconcentration factor of heavy metals generally decreased with the increase of heavy metal concentration in ambient seawater, and maximal content in the organism(CAmax)at the theoretic equilibrium increased with the increase of heavy metal concentration in ambient seawater; (2) During the elimination period, the uptake rate constant of heavy metals and the B1/2 of Cu in C. plicatula were decreased with the increase of heavy metal concentration in ambient seawater (uptake period), and the B1/2 of Cd in C. plicatula had no obvious trend with the exposure concentration; (3)The Cu bioaccumulation ability of C. plicatula was higher than Cd; (4)The bioaccumulation ability of large-size C. plicatula was stronger than small-size ones, indicating that the differences in size of C. Plicatula had no significant effect on the elimination of heavy metals .
