The complex micro-interfacial interaction theories of heavy metal ions such as Pb(II) and Cd(II) adsorption on fine sediment in aqueous solution were not systematically investigated. The aim of this work was to reflect the micro-interfacial adsorption characteristics. Sediment samples were collected from an estuary. The Isothermal and kinetics adsorption experiment were done to acquire the data. Isothermal, kinetics, film diffusion and intraparticle diffusion models were adopted to fit the adsorption experimental data. The results indicated that the Langmuir, Freundlich and Temkin models were suitable for analyzing the isothermal experimental data. The maximum adsorption capacities of Pb(II) and Cd(II) on the sediment were 1.1377 and 0.9821 mg·g⁻¹, respectively. The q_m and K_L of the Langmuir model, K_f and n_F of the Freundlich model, and b and A of the Temkin model all exhibited a power function relationship with the initial adsorbate concentration. The pseudo-second-order model provided a better fit for the experimental kinetics data compared with the fit of the pseudo-first-order and Elovich models. The pseudo-second-order parameters k₂ and q_e of Pb(II) and q_e of Cd(II) both had a power function relationship with adsorption time, additionally, the k₂ of Cd(II) had an exponential function relationship with adsorption time. The liquid-film diffusion parameters k_fd of Pb(II) and Cd(II) were 0.0569 and 0.1806 min⁻¹, respectively. The intraparticle diffusion parameter k_id values of Pb(II) and Cd(II) were 0.0055 mg·g⁻¹·min^1/2 and 0.0049 mg·g⁻¹·min^1/2, respectively. The physical significance of the model parameters showed that Pb(II) adsorption on sediment was stronger than Cd(II). The results of this study provided a theoretical reference for the micro-interfacial mechanism of heavy metal ion adsorption on sediment.

尚未系统地研究重金属离子如Pb（II）和Cd（II）在水溶液中细颗粒沉积物上的复杂微界面相互作用理论。这项工作的目的是反映微界面吸附特性。从河口收集沉积物样品。进行等温和动力学吸附实验以获取数据。采用等温，动力学，膜扩散和颗粒内扩散模型拟合吸附实验数据。结果表明，Langmuir，Freundlich和Temkin模型适用于分析等温实验数据。Pb（II）和Cd（II）在沉积物上的最大吸附容量分别为1.1377和0.9821 mg·g ^-1。的q_米和ķ_大号Langmuir模型的，ķ _˚F和Ñ _˚F的Freundlich模型的，和b和甲所述的Temkin模型的所有表现出与初始吸附物浓度的幂函数关系。与拟一阶模型和Elovich模型的拟合相比，拟二阶模型为实验动力学数据提供了更好的拟合。Pb（II）的伪二级参数k ₂和q _e和Cd（II）的q _e均与吸附时间呈幂函数关系，此外，k ₂Cd（II）的吸附量与吸附时间呈指数关系。Pb（II）和Cd（II）的液膜扩散参数k _fd分别为0.0569和0.1806 min ^-1。Pb（II）和Cd（II）的颗粒内扩散参数k _id值分别为0.0055 mg·g ^-1 ·min ^1/2和0.0049 mg·g ^-1 ·min ^1/2。模型参数的物理意义表明，Pb（II）在沉积物上的吸附要强于Cd（II）。研究结果为沉积物中重金属离子的微界面机理提供了理论参考。