Abstract:Heavy metal pollution in filter-feeding bivalves has received more and more attentions. With regard to the studies in this field, the two-compartment kinetic model is a new mode for rapid determination of bioconcentration factor（BCF）. With a mixed solution of six heavy metals(Cu, Zn, Pb, Cd, Hg,and As), kinetic parameters of bioconcentertion in Ruditapes philippinarum were measured using a two compartment kinetic model. A semi static system was maintained throughout a 15 day exposure period in different concentrations of heavy metals at 15-5±2℃. During the uptake phase, water was changed every day, sufficient to maintain relatively constant concentrations of heavy metals. At 0d, 2d, 5d, 8d, 11d and 15d, R. philippinarum was sampled, and the samples were frozen immediately for the following analysis. Kinetic parameters of bioconcentration were obtained from the two-compartment model by nonlinear curve fitting, including uptake rate constant (k1), elimination rate constant (k2) and bioconcentration factor. The results showed that in the high and medium concentration group the BCF of Cu, Zn, Pb, and Cd in R. philippinarum were 66.99, 18.49, 57.11, 25.81 and 72.46, 35.72, 117.91, 41.83, respectively. Hg, As, and the low concentration group of Cu, Zn, Pb, Cd enrichment regularity was not obvious. The uptake rate constant and bioconcentration factor decreased with the increase of heavy metal exposure concentration in ambient seawater. The ability of accummlation of Cu, Zn, Pb, Cd, Hg, and As in R. philippinarum were Pb>Cu>Cd>Zn. χ2 and F tests for goodness of fit test showed that the fitting data of χ2 value were less than 0.71(critical value), which suggests that the fitting goodness was acceptable. Two-compartment kinetic model could fit well the accumulation of heavy metals in R. philippinarum.
