Study on the concentrations and fractionation of rare earth elements in filtered water, suspended particles and surface sediments of the upper reaches of the Yellow River of China

摘要

The concentrations and fractionation of 14 rare earth elements (REEs) such as La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu in filtered water, suspended particles and surface sediments at 10 sampling sites from Gansu, Ningxia and Inner Mongolia sections of the Yellow River of China were studied by HR-ICP-MS. The results demonstrated that the total concentrations of REEs (∑REEs) in filtered water varied from 0.017 to 0.079 μg/L and had high concentration at S3 (0.079), S1 (0.070) and S4 (0.063) in Inner Mongolia section, while in suspended particles and surface sediments, the ranges were 148.9-246.8 mg/kg (mean 176.4) and 109.9-252.0 mg/kg (mean 179.9), respectively, and showed high concentration at S9 (246.8), S7 (252.0), S8 (229.8) in Baiyin (Gansu section) and S1 (209.5) in Baotou (Inner Mongolia section). The ratios of L/H, δEu and δCe in suspended particles and surface sediments implied light-REEs enrichment in the water compared with the background value of Chinese soil. And the chondrite-normalized REEs patterns of the suspended particles and surface sediments also showed light REEs enrichment at S1, S7, S8 and S9. The high concentrations of REEs in the Yellow River were probably due to the weathering of soil and anthropogenic activities near the river.