为了研究黄河上游表层沉积物与Cd2+和Cu2+的相互作用机理, 以黄河三湖河口表层沉积物(简称样品)为研究对象, 采用电感耦合等离子体质谱(ICP-MS)技术, 优化样品对Cd2+和Cu2+的吸附固液比、 时间、 pH等条件。 并在此条件下研究了Cd2+和Cu2+在样品上的吸附特性和解吸特性。 结果表明: 两种金属的优化吸附条件不同, 在各自优化吸附条件下, 样品对Cu2+ 和Cd2+的平衡吸附量分别为0.88和0.13 mg·g-1; 对两种金属的吸附动力学符合伪二级吸附动力学模型, 且样品对Cu2+的吸附速率大于对Cd2+的吸附速率; 吸附热力学拟合结果显示吸附过程符合Freundlich模型, 对两种金属的吸附均属于优惠型吸附, 且吸附过程属于吸热过程, 可自发进行; 解吸动力学研究表明, 两个金属的解吸过程均符合Elovich方程, 属于非均相扩散; 在多离子竞争吸附-解吸实验中发现, 样品对Cu2+的吸附-解吸受到共存离子的影响更大。 研究结果揭示了黄河三湖河口表层沉积物对Cd2+和Cu2+吸附和解吸的作用机理以及共存离子对吸附解吸特性的影响。 对于分析重金属在水体与沉积物之间的作用机理、 固液两相分布规律以及重金属迁移能力提供了理论依据, 同时也为制定研究区域针对性的重金属防控措施具有一定指导意义。ICP-MS

In order to study the interaction mechanism between Cd2+, Cu2+ and surface sediments in the upper reaches of the Yellow River, the surface sediment of Sanhuhekou (YRSSM) was chosen as research object with inductively coupled plasma mass spectrometry (ICP-MS) as analysis method. The adsorption reaction condition such as liquid-solid ratio, reaction time and pH were optimized, and the adsorption and desorption characteristics of Cd2+ and Cu2+ onto the surface sediments under the optimized experimental conditions were studied. The results showed that the adsorption capacity of Cu2+ was greater than that of Cd2+, the equilibrium absorption capacity were 0.88 and 0.13 mg·g-1 under each optimum experimental condition, respectively. The adsorptions of Cu2+ and Cd2+ were in accord with the pseudo-second-order kinetic, while adsorption rate of Cu2+ was also greater than that of Cd2+. The adsorption thermodynamics data were in accordance with the Freundlich model and the fitting. Results showed that the adsorption process of Cu2+ and Cd2+ belonged to the preferential adsorption, and were endothermic and spontaneous processes. The desorption process showed that the Elovich equation were suitable for Cd2+ and Cu2+ and belonged to the heterogeneous diffusion. Multi-ions competitive adsorption and desorption experiments indicated that Cu2+ was influenced more by co-existing ion. The study revealed not only the mechanism of adsorption and desorption between Cd2+, Cu2+ and surface sediment in Sanhuhekou, but also the influence of coexisting ions on the adsorption and desorption characteristics. The results demonstrated that the distribution mechanism of heavy metals between solid-liquid phases, and provided a theoretical basis for the migration ability of heavy metals. It also had a guiding significance for establishing heavy metals preventive and control measures of the study area.