18 results

Origin and properties of kaolinites from soils of a toposequence in Southern Brazil

Daniela Nicole Ferreira ORCID logo , Vander de Freitas Melo ORCID logo , Samara Alves Testoni ORCID logo , Pablo Vidal-Torrado ORCID logo , Jairo Calderari de Oliveira Junior ORCID logo

25/Mar/2024

ABSTRACT Kaolinite is the main clay mineral in most soils around the world and has been widely used for industrial purposes. This research aimed to study chemical, morphological and crystallographic characteristics of kaolinite, and establish the origin of kaolinitic samples on Serra do Mar and kaolinitic layers on peatlands, located at Southern Brazil. Samples were collected on different geomorphological positions: two samples at Serra do Mar (kaolinitic saprolite – SAP, and kaolinitic layers – KL); and two cores at the […]

Characterization and manipulation of montmorillonite properties towards technological and environmental applications

Vander Freitas Melo ORCID logo , Regiane Salata ORCID logo , Gilberto Abate ORCID logo , Antonio Carlos Azevedo ORCID logo , Larissa Kummer ORCID logo

29/Jul/2021

ABSTRACT The combination of pillarization and charge neutralization with Li+ can make montmorillonite an important support material for industry and decontamination of pollutants in soil and water. Montmorillonite characterization techniques were described in detail, and pillarization procedures were used, after Li+ saturation, to modify and manipulate the chemical and mineralogical surface properties of this montmorillonite. Eight samples were produced: 1) natural montmorillonite (Chisholm Mine – MMT); 2) Li+ saturated montmorillonite (MMTLi); 3) polyethylene glycol (PEG) Al-pillared montmorillonite (AlPEG); 4) PEG […]

Sand fraction is not suitable for forensic investigations in subtropical soils

Vander Freitas Melo ORCID logo , Samara Alves Testoni ORCID logo , Lorna Anne Dawson ORCID logo , Fábio Augusto da Silva Salvador ORCID logo

16/Jul/2020

ABSTRACT Most of the forensic comparison of soils has focused on the clay and silt fractions at the expense of the coarser particles. This study aimed to test the potential of elemental and physical analyses in the sand fraction from subtropical soils to discriminate samples collected in areas under different parent material (claystone and marble) and in areas with the same parent material at a simulated crime scene. Scanning electron microscopy coupled to an energy dispersive X-ray spectrometer (SEM-EDS) analysis […]

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Mineralogical Evolution of Magnetic Rhodic Oxisols under Different Lithological Influences in Brazil

Luiz Aníbal Silva Filho ORCID logo , João Carlos Ker ORCID logo , Maurício Paulo Ferreira Fontes ORCID logo , Danilo de Lima Camêlo ORCID logo , Marcelo Metri Corrêa ORCID logo , Luis Carlos Duarte Cavalcante ORCID logo , [...]

25/Sep/2019

ABSTRACT Ferrimagnetic Fe-oxides are important soil components, which are present in most of the agricultural soils of Brazil. Distinction, origin, and assessment of the influence of these minerals on magnetism and geochemistry is a challenge for mineralogists. This study aimed to characterize mineralogically Fe-rich Rhodic Oxisols ( Latossolos Vermelhos ) originating from several mafic rocks in Brazil, and assess the implications on their magnetic and geochemical properties. We present results on magnetic measurements, chemical dissolutions, X-ray diffractometry, Rietveld refinement, Raman, […]

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Validation of a Standard Operating Procedure (SOP) for Forensic Soils Investigation in Brazil

Samara Alves Testoni ORCID logo , Vander Freitas Melo ORCID logo , Lorna Anne Dawson ORCID logo , Fábio Augusto da Silva Salvador ORCID logo , Paulo Akira Kunii ORCID logo

04/Sep/2019

ABSTRACT Soil traces are useful as forensic evidence due to their potential to transfer and adhere to different types of surfaces on a range of objects or persons. Several works have been developed in forensic soils, under different analytical approaches. However, in Brazil, only the researches from the Group of the Federal University of Paraná have developed works with soils under a forensic approach. Focus has been given on the sequential chemical analyses and mineralogical techniques once they presented a […]

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Do Aggregate Size Classes of the Subsurface Soil Horizon Have Different Chemical/Mineralogical Properties?

Rolff Vladimir Mitton, Vander Freitas Melo ORCID logo , Volnei Pauletti

06/Feb/2019

ABSTRACT Variations in chemical and mineralogical properties of a soil can occur at short vertical and horizontal distances. The objective of the present study was to evaluate the chemical and mineralogical soil properties of different aggregate classes from young (Ustrochrept) and highly weathered (Acrustox) soils from the state of Paraná, Brazil. Undisturbed blocks (0.20 ×0.20 ×0.20 m) of soils were separated into aggregate classes: Acrustox – 8.0-4.0 mm; 4-2 mm; 2.0-0.5 mm; 0.5-0.2 mm; and <0.2 mm; and Ustrochrept – […]

Clay Mineralogy of Subtropical Soils under Long-Term Organic Fertilization in No-Tillage Systems

Fabrócio de Araújo Pedron, Cledimar Rogério Lourenzi, Carlos Aberto Ceretta, Juliana Lorensi, Adriana Cancian

03/May/2018

ABSTRACT: Organic fertilization effect on physical-chemical properties in no-tillage systems in tropical soils has been widely investigated, but little is known about the effects of this practice on the mineralogy of the clay fraction. This study aimed to evaluate the clay-fraction mineralogy of two subtropical soils, fertilized with organic residues in long-term no-tillage systems. An Alfisol fertilized with 0, 40, and 80 m3 ha-1 yr-1 pig slurry was evaluated for eight years, and an Oxisol with 0, 8, and 16 […]

Identification of Heavy Metals in Crystals of Sand and Silt Fractions of Soils by Scanning Electron Microscopy (SEM EDS/WD-EPMA)

Araína Hulmnn Batista, Vander Freitas Melo, Robert Gilkes, Malcolm Roberts

02/Mar/2018

ABSTRACT Studies of heavy metals are concentrate on clay fractions, but coarser fractions of the soil can constitute significant sources of structural forms of heavy metals. The aim of this study was to evaluate the occurrence of heavy metals in the structure of minerals of the sand and silt fractions of soils from three different parent materials (metamorphic rocks and granite) in southern Brazil using SEM/EDS – Scanning Electron Microscopy with Energy Dispersive Spectroscopy and with WD-EPMA – with Wavelength […]

Clay Mineralogy of Basaltic Hillsides Soils in the Western State of Santa Catarina

Jaime Antonio de Almeida, Janaina Corrêa, Catiline Schmitt

01/Feb/2018

ABSTRACT A commonly accepted concept holds that highly fertile, shallow soils are predominant in the Basaltic Hillsides of Santa Catarina State, in southern Brazil, but their agricultural use is restricted, either by excessive stoniness, low effective depth or steep slopes. Information about soil properties and distribution along the slopes in this region is, however, scarce, especially regarding genesis and clay fraction mineralogy. The objective of this study was to evaluate soil properties of 12 profiles distributed in three toposequences (T) […]

Mineralogy of the Clay Fraction and Chemical Properties of Soils Developed from Sedimentary Lithologies of Pirambóia, Sanga-the-Cabral and Guará Geological Formations in Southern Brazil

Pablo Grahl dos Santos, Jaime Antonio de Almeida, Letícia Sequinatto

24/Aug/2017

ABSTRACT Quali-quantitative and crystallographic characterizations of the different minerals of a soil are essential for the best evaluation of its genesis, degree of weathering, active pedogenetic processes, physical and chemical properties, and its potential reserve of mineral nutrients. This study presents the results of mineralogical investigations carried out to verify the influence of the different lithologies of three geological formations of a sedimentary nature on the mineralogical composition of the soils and the relation of this mineralogical composition to soil […]

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