CHARACTERIZATION OF THE SPATIAL DISTRIBUTION AND SOURCES OF RARE EARTH ELEMENTS (REE’s) IN SURFICIAL SEDIMENTS OF WINAM GULF (KENYA)

The status and fate of rare earth elements (REE’s) in aquatic environments is still not well prioritized in sediment monitoring studies, yet their application in industry, agriculture and health is widespread. Contemporary strategies to transition to cleaner energy and technologies predict an increased demand for critical mineral elements, especially Lithium (Li), Copper (Cu), Cobalt (Co), Nickel (Ni) and REE’s. A grid sampling study was used to characterize the occurrences and spatial distribution of REE’s in surficial sediments of the Winam gulf and to understand the spatial profile and possible influencing sedimentary processes within the freshwater sedimentary basin. The concentration of Lanthanum (La), Cerium (Ce), Praseodynium (Pr), Neodymium (Nd) ranged from 4.815 to 685.32 mg/Kg in surficial sediments. However appreciably lower levels ranging from 0.099 to 27.736 mg/Kg were recorded for the rest of the REE’s (Samarium, Sm, Europium, Eu, Gadolinium, Gd, Terbium, Tb, Dysporium, Dy, Holmium, Ho, Erbium, Er, Thulium, Tm, Ytterbium, Yb and Lutetium, Lu). The transition metal, Ytrrium (Y) ranged from 9.46 to 97.26 mg/Kg. The spatial patterns revealed lower and less variable contents of for Eu, Tb, Ho, Tb, Tm, Lu compared to the rest of the elements. We recommend further geochemical monitoring of the benthic environment for better understanding of the REE’s distribution, controls and fate within the freshwater aquatic ecosystem.