Determination, fractionation, and speciation of Rare Earth Elements (REEs) in Brazilian Amazon rivers: understanding the biogeochemical behavior of REEs in Rio Negro, Solimões and Amazon basins

• Grant number: 23/11694-5
• Support Opportunities: Regular Research Grants
• Start date: May 01, 2024
• End date: April 30, 2026
• Field of knowledge: Physical Sciences and Mathematics - Chemistry - Analytical Chemistry
• Principal Investigator: Amauri Antonio Menegário
• Grantee: Amauri Antonio Menegário
• Host Institution: Centro de Estudos Ambientais (CEA). Universidade Estadual Paulista (UNESP). Campus de Rio Claro. Rio Claro , SP, Brazil
• Associated researchers: Ana Beatriz Santos da Silva ; Brian Quinn ; Daniele Kasper ; Ezio Sargentini Junior ; Johanna Irrgeher ; José Lucas Martins Viana ; Melina Borges Teixeira Zanatta ; Paul Nicholas Williams ; Stefan Wagner ; Thomas Prohaska

Abstract

Particle flows transported by the Amazon River and its main tributaries play a crucial role in the biogeochemical cycling of nutrients and trace elements, acting as vectors from land to sea.The lanthanide series - rare earth elements (REE), have special geochemical significance due to their shared chemical properties. Their abundance patterns in aquatic systems can thus be used to understand key weathering and river transport processes. The ratios between light and heavy REEs can be particularly relevant in this "fingerprinting" approach. However, interpreting these patterns requires knowledge of REE fractionation characteristics (linked to their labilities and chemical forms), reflecting specific solid-to-dissolved phase transfer conditions. This makes REE fractionation and speciation challenging, especially in the Amazon region. Technologies like passive samplers, DGT (Diffusive Gradients in Thin Films), have been developed to assess the labile nature of trace elements by collecting analytes in situ, not only preserving but also pre-concentrating them for improved subsequent determinations. Despite their importance, there are only a few studies using DGT in freshwater, and none in the Amazon, to evaluate REE labilities.In recent decades, inductively coupled plasma mass spectrometry (ICP-MS) has evolved to nanoparticles analyze (NPs) through the sp-ICP-MS technique, based on pulses of ions generated from the plasma. The use of sp-ICP-MS, particularly for REEs in aquatic environments, holds promise for revealing intriguing aspects of NP behavior in water.This project aims to advance on the speciation and chemical fractionation of REEs in the Amazon basin to enhance understanding of natural biogeochemical processes and contamination risks in the region. Specifically tailored analytical methods based on DGT and sp-ICP-MS will be developed for the region. The research will encompass different aquatic systems, such as the Negro and Solimões rivers, with a focus on REE behavior at the confluence point (meeting of rivers - the Amazon River). Additionally, it will examine potential impacts of industrial activities in Manaus on the Rio Negro. The study aims to contribute to understanding element cycles and associated threats in the Amazon basin.As an international endeavor, the project will involve collaborations between researchers from the Amazon Research Institute, Federal University of Minas Gerais, Queen's University Belfast (UK), and Montanuniversität Leoben (Áustria). (AU)

Scientific publications

(References retrieved automatically from Web of Science and SciELO through information on FAPESP grants and their corresponding numbers as mentioned in the publications by the authors)

LIMA, GUILHERME DOS SANTOS; SUAREZ, CARLOS ALFREDO; GEMEINER, HENDRYK; SERAFINI, PATRICIA PEREIRA; DE DEUS, JEAN PABLO ALVES; VIANA, JOSE LUCAS MARTINS; MENEGARIO, AMAURI ANTONIO. Potentially toxic elements (PTEs) in seabirds foraging across a heterogeneous landscape: Cross-species bioaccumulation patterns. Environmental Pollution, v. 367, p. 11-pg., 2025-02-15. (23/15970-7, 23/11694-5)