Banca de DEFESA: ANA BEATRIZ MATOS RODRIGUES

Uma banca de DEFESA de MESTRADO foi cadastrada pelo programa.
STUDENT : ANA BEATRIZ MATOS RODRIGUES
DATE: 24/02/2023
TIME: 14:00
LOCAL: Por videoconferência
TITLE:

Properties and environmental quality of overburden and by-product of manganese mining in the southeastern Amazon

KEY WORDS:

Potentially toxic elements; mining by-product; contamination levels;
ecological risks

PAGES: 87
BIG AREA: Ciências Agrárias
AREA: Agronomia
SUBÁREA: Ciência do Solo
SPECIALTY: Química do Solo
SUMMARY:

Knowledge of the characteristics of materials produced in manganese (Mn) mining in
southeastern Amazonia may be essential for defining contamination levels and for
correct environmental management in altered areas. In this sense, the objectives of this
study were to characterize the properties and determine the pseudototal and bioavailable
concentrations of potentially toxic elements (PTEs) in soils, overburden and by-product
of Mn mining at the Azul mine, southeastern Amazonia. For this purpose, samples were
collected from overburden piles and Mn mining by-products, as well as soils from
native forests, considered as reference. The samples were characterized in terms of
chemical properties and granulometry. Mn, barium (Ba), copper (Cu), molybdenum
(Mo), nickel (Ni), lead (Pb) and zinc (Zn) concentrations were determined by acid
digestion and inductively coupled plasma mass spectrometry. Bioavailability was
obtained using the sequential extraction proposed by the Community Bureau of
Reference. The results were used to estimate contamination rates and ecological risks.
The pH values of the forest soil and the by-product were more acidic than in the
overburden, and the organic matter contents were higher in the reference forest area. All
EPTs showed higher concentrations in waste and by-product, especially Mn, Ba and Cu.
In these same materials, Mn, Ba, Cu, Zn and Pb had greater enrichment and
contamination. The ecological risk index was high in overburden (309.55) and by-
product (592.67). The chemical fractionation revealed that all EPTs predominate in the
residual form, with percentage concentrations above 60% of the pseudototal
concentration, revealing the strong association of the elements with the crystalline
structures of the minerals and the low risk of environmental contamination. The results
of this study may support more efficient monitoring and the development of new
technologies for mineral processing and environmental recovery in Mn exploration
areas.

BANKING MEMBERS:
Externo à Instituição - GABRIEL SALOMÃO - ITV
Externa à Instituição - EDNA SANTOS DE SOUZA - UNIFESSPA
Externo à Instituição - PAULA GODINHO RIBEIRO - ITV
Presidente - 030.493.086-56 - SILVIO JUNIO RAMOS - ITV