Cu、Cd、Pb在翅碱蓬体内富集动力学研究

Kinetics of Enrichment of Several Heavy Metals in Suaeda heteroptera

采用半静态双箱动力学模型在室内拟合翅碱蓬对三种重金属Cu、Cd、Pb的生物富集过程。在富集过程中通过非线性拟合获得翅碱蓬对三种重金属的吸收速率常数(K_(1))、释放速率常数(K_(2))、生物富集因子(BCF)、以及平衡状态下生物体内三种重金属的含量(C_(max))、生物学半衰期(t_(1/2))等动力学参数。拟合结果表明:Cu在翅碱蓬中富集动力学参数K_(1)、K_(2)、BCF、C_(max)、t_(1/2)的平均值分别为3.111、0.17、6.42、335μg/g、3.66 d。Cd在翅碱蓬中富集动力学参数K_(1)、K_(2)、BCF、C_(max)、t_(1/2)的平均值分别为0.346、0.172、2.26、39.5μg/g、4.03 d。Pb在翅碱蓬中富集动力学参数K_(1)、K_(2)、BCF、C_(max)、t_(1/2)的平均值分别为7.64、0.196、26.88、519.3μg/g、4.45 d。试验发现Pb、Cu在低中高三种浓度下均符合半静态双箱动力学模型,Cd在低浓度时符合双箱动力学模型。此外,翅碱蓬对三种重金属的富集能力排序为Pb>Cu>Cd。

In this paper,a semi-static two-box kinetic model was used to simulate the bioaccumulation process of Suaeda heteroptera on three heavy metals Cu,Cd and Pb.In the enrichment process,kinetic parameters such as absorption rate constant(K_(1)),release rate constant(K_(2)),bioconcentration factor(BCF),contents of three heavy metals in organisms under equilibrium state(C_(max)),biological half-life(t_(1/2))and the like of S.heteroptera for three heavy metals were obtained through nonlinear fitting.The fitting results showed that the average values of kinetic parameters K_(1),K_(2),BCF,C_(max) and t_(1/2) of Cu enrichment in S.heteroptera are 3.111,0.17,6.42,335μg/g and 3.66 d respectively.The average values of kinetic parameters K_(1),K_(2),BCF,C_(max) and t_(1/2) of Cd enrichment in S.heteropter a were 0.346,0.172,2.26,39.5μg/g and 4.03 d respectively.The average values of kinetic parameters K_(1),K_(2),BCF,C_(max) and t_(1/2) of Pb enrichment in S.heteroptera were 7.64,0.196,26.88,519.3μg/g and 4.45 d respectively.Experiment results showed that Pb and Cu conformed to the semi-static two-box dynamic model at low,medium and high concentrations,while Cd conforms to the two-box dynamic model at low concentrations.In addition,the enrichment ability of S.heteroptera to three heavy metals was Pb>Cu>Cd.