Cerium (Ce) is the most abundant Rare Earth Element (REE) in the Upper Continental Crust (UCC), is globally known as an indispensable ingredient for modern technologies, and has recently been recognized as an emerging micro-contaminant in the fluvial environment. The present study deals with the Ce content in bedload sediments and suspended sediments, collected from the Gomati River. Ce concentrations constitute nearly 43% of the total REE that ranging from 23.20 to 299.92 µg/g (average: 80.88 µg/g) in bedload and 30.83 to 157.21 µg/g (average: 85.77 µg/g) in suspended sediment, which is much higher than UCC (64.0 µg/g) and Average Sediments (58.9 µg/g). The isolated peak with > 3-fold enrichment in longitudinal Ce profile displays the significant input of the mica-rich weathered materials in the middle river segment due to upliftment of the subsurface Faizabad Ridge. The concentration of Ce in biotite separated from the bedload sediments shows a progressively downstream increasing trend, with concentrations of 158.8 µg/g (Naimesarayan), 198.9 µg/g (Haidergarh), 284 µg/g (Kurwar), and 638.9 µg/g (Chandwak). Anthropogenic assessment of these sediments shows the geochemical imprints of Ce contamination in the river system under the sub-tropical climatic condition and offers future research opportunities associated with Ce toxicity with its effect on the environment, human health, and aquatic life.
Yadav et al. (Tue,) studied this question.