Application of the fundamental parameter method to the assessment of major and trace elements in soil and sediments from Osamu Utsumi uranium mine by WDXRF

Sabine Neusatz Guilhen,Marcos Antônio Scapin,Marycel Elena Barboza Cotrim,Solange Kazumi Sakata

doi:10.1590/0370-44672018720146

Abstract

Abstract Wavelength dispersive X-ray fluorescence spectrometry (WDXRF) is a suitable technique for the characterization of contaminated mining sites, providing a quick and reliable screening for areas of significant contamination. This study established and validated a non-destructive methodology for quantitative simultaneous determination of major and minor constituents in soil and sediments by WDXRF, which was further applied to quantify soil and sediment samples from Osamu Utsumi uranium mine (Caldas, Minas Gerais, Brazil). Elements such as Ce, La, Nd, Mn and U were found in more concentrated levels in the calcium diuranate deposit (DUCA), whereas Fe and Al were found at higher levels in the soil samples corresponding to sites where accentuated leaching processes have occurred. Comparatively, the levels of U and rare-earth elements were found in significantly higher levels in the sediments retrieved from the mine’s pit as a result of acid mine drainage. These findings are believed to be useful as an initial environmental assessment for the decommissioning process of the mine.

Highlights

Acid mine drainage (AMD), one of the most serious problems resulting from mining industrial activities, results from the oxidation of sulfide minerals present in the wastes [Doyle, 1990; Sima et al, 2011]
The plants and cover crops’ growth get inhibited, causing erosion of the soil and an imminent contamination threat to streams and aquifers [Lyew & Shepard, 1997; Nóbrega et al, 2008], since the chemical elements originated from the acid mine drainage (AMD) can spread up to hundreds of kilometers from the mining area
This study aims to establish and validate a non-destructive quantitative chemical analysis methodology for simultaneous determination of major and minor constituents in soil and sediments from Osamu Utsumi uranium mine and vicinities by wavelength dispersive X-ray fluorescence spectrometry (WDXRF)

Summary

Introduction

Acid mine drainage (AMD), one of the most serious problems resulting from mining industrial activities, results from the oxidation of sulfide minerals present in the wastes [Doyle, 1990; Sima et al, 2011]. This process releases H+ ions, lowering the pH and creating conditions under which metals can be leached [Blodau, 2006]. The plants and cover crops’ growth get inhibited, causing erosion of the soil and an imminent contamination threat to streams and aquifers [Lyew & Shepard, 1997; Nóbrega et al, 2008], since the chemical elements originated from the acid mine drainage (AMD) can spread up to hundreds of kilometers from the mining area. The effects can linger on for long periods of time, even after the cessation of mining activities [Salomons, 1995; Borma & Soares, 2002]

Objectives

Methods

Findings

Conclusion