Speciation and mobilization of iron and aluminium oxides and (oxy)hydroxides on soils surrounding saline-alkaline lakes of Nhecolândia wetland, Pantanal, Brazil.

• Grant number: 22/08959-4
• Support Opportunities: Scholarships abroad - Research Internship - Doctorate
• Start date: November 01, 2022
• End date: October 31, 2023
• Field of knowledge: Physical Sciences and Mathematics - Geosciences - Geology
• Principal Investigator: Célia Regina Montes
• Grantee: André Renan Costa Silva
• Supervisor: Yves Marie Pierre Henri Lucas
• Host Institution: Centro de Energia Nuclear na Agricultura (CENA). Universidade de São Paulo (USP). Piracicaba , SP, Brazil
• Institution abroad: Université de Toulon (UTLN), France
• Associated to the scholarship: 19/21157-1 - Geochemical and mineralogical control of the soil-lagoon system functioning of Nhecolândia, Pantanal, Mato Grosso do Sul, BP.DR

Abstract

This project aims to evaluate speciation in solid phases and the availability of iron and aluminum in clay neoformations, in the southern region of Nhecolândia, Pantanal. Soils surrounding lakes with saline-alkaline waters of different colors, present significant contrasts between physical-chemical parameters and different mineralogical contributions. Thus, soils and lakes with different characteristics coexist in a single environment, separated by short distances. For this reason, pedogenetic processes such as secondary mineral neoformations are important for understanding the soil-lake system found in Nhecolândia. By means of pH-static batch leaching tests, sequential selective extractions and models of metallic speciation (ORCHESTRA) and thermodynamics (PHREEQ-C), this project seeks the nature and mobility of iron and aluminum oxides and oxy-hydroxides, sometimes studied as hydrous ferric oxides (HFO). These mineral phases are extremely important in soils, due to the variation of behavior in different environmental conditions and their association with different constituents of the environment. Through these studies, it will be possible to identify the main reactions that take place between liquid and solid phases in the environment, better understand the functioning of the active biogeochemical cycle and refine data obtained through mineralogical techniques. (AU)