Anthropogenic gadolinium anomalies and rare earth elements in the water of Atibaia River and Anhumas Creek, Southeast Brazil

Author(s)

de Campos, Francisco Ferreira ^{[1, 2]} ; Enzweiler, Jacinta ^[1]

Affiliation

^[1] Univ Estadual Campinas, Inst Geosci, CP 6152, BR-13083970 Campinas, SP - Brazil

^[2] Geol Survey Brazil, Rua Costa 55, BR-01304010 Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: ENVIRONMENTAL MONITORING AND ASSESSMENT; v. 188, n. 5 MAY 2016.
• Web of Science Citations: 9

Abstract

The concentrations of rare earth elements (REE), measured in water samples from Atibaia River and its tributary Anhumas Creek, Brazil, present excess of dissolved gadolinium. Such anthropogenic anomalies of Gd in water, already described in other parts of the world, result from the use of stable and soluble Gd chelates as contrast agents in magnetic resonance imaging. Atibaia River constitutes the main water supply of Campinas Metropolitan area, and its basin receives wastewater effluents. The REE concentrations in water samples were determined in 0.22-mu m pore size filtered samples, without and after preconcentration by solid-phase extraction with bis-(2-ethyl-hexyl)-phosphate. This preconcentration method was unable to retain the anthropogenic Gd quantitatively. The probable reason is that the Gd chelates dissociate slowly in acidic media to produce the free ion that is retained by the phosphate ester. Strong correlations between Gd and constituents or parameters associated with effluents confirmed the source of most Gd in water samples as anthropogenic. The shale-normalized REE patterns of Atibaia River and Anhumas Creek water samples showed light and heavy REE enrichment trends, respectively. Also, positive Ce anomalies in many Atibaia River samples, as well as the strong correlations of the REE (except Gd) with terrigenous elements, imply that inorganic colloidal particles contributed to the REE measured values. (AU)

• FAPESP's process: 12/02486-5 - Anthropogenic anomalies of rare earth elements (REE) in Atibaia river and some of its tributaries in the region of Paulínia (SP)
• Grantee: Francisco Ferreira de Campos
• Support Opportunities: Scholarships in Brazil - Master
• FAPESP's process: 12/05024-2 - Hidrogeochemistry of lanthanoids in river and ground waters: case studies in Campinas, SP
• Grantee: Jacinta Enzweiler
• Support Opportunities: Regular Research Grants