Bed and suspended sediment-associated rare earth element concentrations and fluxes in a polluted Brazilian river system

• Published in: Environmental science and pollution research international 2018-12, Vol.25 (34), p.34426-34437
• Main Authors: da Silva, Yuri Jacques Agra Bezerra, do Nascimento, Clístenes Williams Araújo, da Silva, Ygor Jacques Agra Bezerra, Amorim, Fábio Farias, Cantalice, José Ramon Barros, Singh, Vijay P., Collins, Adrian L.
• Format: Article
• Language: English
• Subjects: Agricultural management; Agricultural wastes; Agriculture; Anthropogenic factors; Aquatic Pollution; Atmospheric Protection/Air Quality Control/Air Pollution; Bed load; Brazil; Cerium; Earth; Earth and Environmental Science; Ecotoxicology; Environment; Environmental Chemistry; Environmental Health; Environmental Monitoring - methods; Environmental science; Erbium; Fluxes; Gadolinium; Geologic Sediments - analysis; Household wastes; Metals, Rare Earth - analysis; Pollutants; Pollution dispersion; Pollution sources; Rare earth elements; Research Article; Rivers; Rivers - chemistry; Sediment samplers; Sediments; Soil - chemistry; Soil conditions; Soil Pollutants - analysis; Stream pollution; Suspended sediments; Trace elements; Waste Water Technology; Wastewater; Water Management; Water Pollutants, Chemical - analysis; Water pollution; Water Pollution Control; Ytterbium
• ISSN: 0944-1344; 1614-7499
• DOI: 10.1007/s11356-018-3357-4

Rare earth elements (REEs) have been recently recognized as emergent pollutants in rivers. However, data regarding REE fluxes in association with either bed or suspended are scarce. To address this knowledge gap, we determined the concentrations and fluxes of La, Ce, Pr, Nd, Sm, Eu, Gd, Yb, Lu, Dy, Er, Ho, Tb, and Tm in bed and suspended sediment samples of a representative polluted Brazilian River. Sediment-associated data on REEs were placed in the context of corresponding background concentrations in soils under natural conditions along the Ipojuca watershed. Light rare earth elements (LREEs) comprised more than 94% of the total REEs associated with bed and suspended sediments. Suspended sediments accounted for more than 95% of the total REE flux. The Ce and Nd fluxes of about 7 t year −1 underscore the importance of including REEs in future estimations of global suspended sediment-associated element fluxes. In contrast, bedload often transported less than 0.0007 t year −1 of each REE. The main sources of pollution in the Ipojuca River are anthropogenic, likely due to domestic effluent and waste water from industrial and agricultural operations—major causes of sediment-associated Gd transport in polluted streams.