Comparison of Pb(II), Cu(II), Cd(II), and Ni(II) adsorption onto surficial sediment components from aquatic environments in the Phaeozem zone of Northeast China

The Yinma River is a typical river located in the core region of the Phaeozem zone in Northeast China. The adsorption of trace metals including Pb(II), Cu(II), Cd(II), and Ni(II) onto surficial river and reservoir sediments from Yinma River and their components was investigated. The adsorption capacity of sediment components i.e., organic matter (OM), Fe oxides, Mn oxides and residual materials was compared via selective extraction followed by adsorption experiments and statistical analysis. Adsorption data were analyzed via nonlinear least-squares fitting to estimate the adsorption parameters of each component based on Langmuir adsorption isotherm model. The results indicated that Pb(II) and Cu(II) demonstrated a greater affinity for sediment adsorption than Cd(II) and Ni(II). The reservoir sediment exhibited a higher adsorption capacity for trace metals than that for the river sediment. Unlike results from previous studies, Fe/Mn oxides represented a significant contribution to the adsorption of trace metals rather than OM and residual materials. Additionally, the adsorption capacity of Fe/Mn oxides in different sediments differed due to the diversity of Fe/Mn oxides, whereas for OM, the adsorption capacity to different trace metals showed limited variation. Overall, the results from this study indicated that both Fe oxides and Mn oxides exerted a vital influence on the adsorption of trace metals in sediments from natural aquatic environments in the Phaeozem zone, Northeast China.