scholarly journals Geochemical and radioctivity characterization of rocks from the Rio Preto (GO) project

2012 ◽  
Vol 30 (4) ◽  
pp. 399
Author(s):  
Cynthia Romariz Duarte ◽  
Daniel Marcos Bonotto ◽  
Marco Aurélio Farias de Oliveira
Keyword(s):  
Gamma Ray ◽  
Organic Matter Content ◽  
Uranium Content ◽  
Matter Content ◽  
Gamma Ray Spectrometry ◽  
Weathering Processes ◽  
Lower Member ◽  
Ratio Data ◽  
238U Activity

A extinta Nuclebrás, no final da década de 70 e início dos anos 80, conduziu o Projeto Rio Preto, por intermédio do qual efetuou o mapeamento geológico básico e a caracterização radiométrica por aerogamaespectrometria, sem discriminação de canais, da região nordeste do estado de Goiás, Brasil, a oeste da área do Parque Nacional da Chapada dos Veadeiros, perfazendo um total de 650 km2 e englobando a confluência dos Rios Claro e Preto. Os radioelementos naturais U, Th e 40K do Projeto Rio Preto (GO) foram posteriormente caracterizados por espectrometria gama aplicada aproximadamente a 300 amostras, a qual foi conduzida no LABIDRO-Laboratório de Isótopos e Hidroquímica do Departamento de Petrologia e Metalogenia do Instituto de Geociências e Ciências Exatas da UNESP-Campus de Rio Claro. Este trabalho descreve para todas as amostras os resultados obtidos na caracterizaçãoao petrográfica e análise química dos principais óxidos (SiO2, TiO2, Al2O3, Fe2O3, MgO, MnO, K2O, Na2O, CaO e P2O5), os quais foram utilizados na avaliação da ocorrência dos radioelementos naturais naquela área. Também são apresentados resultados do teor de matéria orgânica obtido por colorimetria em amostras selecionadas de diferentes litotipos para melhor investigar a possibilidade de relação entre a grafita e os radioelementos urânio e tório. Finalmente, dados da concentração de urânio e razão de atividade 234U/238U em amostras selecionadas de xistos e gneisss da Formação Ticunzal – Membro Inferior sugeriram a influência de processos intempéricos na área.ABSTRACT: The Rio Preto Project, developed by the extinct Brazilian nuclear state company, Nuclebrás, during the late 70s and early 80s, consisted of basic geologicalmapping and radiometric characterization by aerogeophysical gamma-ray spectrometry, without channel discrimination, of a surface area of 650 km2 located to the westof the Chapada dos Veadeiros National Park on the northeastern of Goiás State, Brazil, including the confluence area of Claro and Preto Rivers. Additionaly, the naturalradioelements U, Th and 40K were determined by gamma-ray spectrometry in 300 rock samples from cores of the Rio Preto Project area. The tests were conducted at LABIDRO-Isotopes and Hydrochemistry Laboratory of the Departamento de Petrologia e Metalogenia of the Instituto de Geociências e Ciências Exatas, UNESP, in RioClaro, SP, Brazil. This paper reports the results of petrographic characterization and chemical analyses of major oxides (SiO2, TiO2, Al2O3, Fe2O3, MgO, MnO, K2O,Na2O, CaO and P2O5) for all samples used to determine the natural radioelements present in the region. The organic matter content results obtained by colorimetryare also reported for selected cores of different lithotypes in order to investigate the possible relationship between graphite and the radioelements uranium and thorium.Finally, uranium content and 234U/238U activity ratio data for selected samples of schists and gneisses of the Lower Member of the Ticunzal Formation suggest theinfluence of weathering processes in the area.Keywords: Rio Preto (GO) Project, natural radioelements, gamma and alpha spectrometry. 

scholarly journals Radioactivity measurements in soils surrounding four coal-fired power plants in Serbia by gamma-ray spectrometry and estimated dose

2014 ◽  
Vol 29 (4) ◽  
pp. 296-306 ◽  
Author(s):  
Ivana Vukasinovic ◽  
Dragana Todorovic ◽  
Natasa Nikolic ◽  
Ana Mihajlovic-Radosavljevic ◽  
Snezana Nenadovic ◽  
...  
Keyword(s):  
Power Plants ◽  
Gamma Ray ◽  
Surface Soil ◽  
Natural Radionuclides ◽  
Organic Matter Content ◽  
Matter Content ◽  
Gamma Ray Spectrometry ◽  
Carbonate Content ◽  
Activity Levels ◽  
Radioactivity Measurements

The study of spatial distribution of activity concentration of 238U, 226Ra, 210Pb, 232Th, 40K, and 137Cs radionuclides in the surface soil samples (n = 42) collected in the vicinity of four coal-fired power plants in Serbia is presented. Radioactivity measurements in soils performed by gamma-ray spectrometry showed values [Bqkg-1] in the range: 15-117 for 238U, 21-115 for 226Ra, 33-65 for 210Pb, 20-69 for 232Th, 324-736 for 40K, and 2-59 for 137Cs. Surface soil radio-activity that could have resulted from deposition of radionuclides from airborne discharges or resuspension of ash from disposal sites showed no enhanced levels. It was found that variation of soil textural properties, pH values, and carbonate content influenced activity levels of natural radionuclides while radiocesium activities were associated with soil organic matter content. Modification of some soil properties was observed in the immediate vicinity (<1 km) of power plants where the soil was more alkaline with coarser particles (0.2-0.05 mm) and carbonates accumulated. Calculated average values of the absorbed gamma dose rate and annual external effective dose originating from the terrestrial radionuclides were 69.4 nGy/h and 0.085 mSv, respectively.

scholarly journals STATISTICAL MULTIVARIATE ANALYSIS APPLIED TO ENVIRONMENTAL CHARACTERIZATION OF SOIL IN SEMIARID REGION1

2019 ◽  
Vol 32 (1) ◽  
pp. 200-210
Author(s):  
Antônio Italcy de Oliveira Júnior ◽  
Luiz Alberto Ribeiro Mendonça ◽  
Sávio de Brito Fontenele ◽  
Adriana Oliveira Araújo ◽  
Maria Gorethe de Sousa Lima Brito
Keyword(s):  
Organic Matter Content ◽  
Principal Component ◽  
Matter Content ◽  
Multivariate Statistical ◽  
Statistical Tool ◽  
Environmental Characterization ◽  
Hierarchical Grouping ◽  
Two Factors ◽  
Total Data

ABSTRACT Soil is a dynamic and complex system that requires a considerable number of samples for analysis and research purposes. Using multivariate statistical methods, favorable conditions can be created by analyzing the samples, i.e., structural reduction and simplification of the data. The objective of this study was to use multivariate statistical analysis, including factorial analysis (FA) and hierarchical groupings, for the environmental characterization of soils in semiarid regions, considering anthropic (land use and occupation) and topographic aspects (altitude, moisture, granulometry, PR, and organic-matter content). As a case study, the São José Hydrographic Microbasin, which is located in the Cariri region of Ceará, was considered. An FA was performed using the principal component method, with normalized varimax rotation. In hierarchical grouping analysis, the “farthest neighbor” method was used as the hierarchical criterion for grouping, with the measure of dissimilarity given by the “square Euclidean distance.” The FA indicated that two factors explain 75.76% of the total data variance. In the analysis of hierarchical groupings, the samples were agglomerated in three groups with similar characteristics: one with samples collected in an area of the preserved forest and two with samples collected in areas with more anthropized soils. This indicates that the statistical tool used showed sensitivity to distinguish the most conserved soils and soils with different levels of anthropization.

scholarly journals Characterization of the Primary Sludge from Pharmaceutical Industry Effluents and Final Disposition

Processes ◽  
2019 ◽  
Vol 7 (4) ◽  
pp. 231 ◽  
Author(s):  
Renata Xavier Alberico Freitas ◽  
Lara Aguiar Borges ◽  
Handray Fernandes de Souza ◽  
Fernando Colen ◽  
Alex Sander Rodrigues Cangussu ◽  
...  
Keyword(s):  
Sewage Sludge ◽  
Organic Matter Content ◽  
Oxygen Demand ◽  
Physicochemical Characteristics ◽  
Matter Content ◽  
Primary Sludge ◽  
Volatile Solids ◽  
Object Of Study ◽  
Final Disposition

The generation of large volumes of waste by industrial processes has become an object of study because of the necessity to characterize the composition of residues in order to suggest appropriate treatments and to minimize adverse environmental impacts. We performed analyses of total fixed and volatile solids, moisture, and chemical oxygen demand (COD). We found high organic matter content. We also measured physicochemical characteristics, including corrosivity, reactivity, and toxicity. Sewage sludge showed levels of chloride and sodium above the maximum allowed limits. These data suggest the potential for anaerobic digestion as a treatment option for sewage sludge and for its use as a biofertilizer.

Groundtmthing Multibeam Bathymetric Surveys of Finfish Aquaculture Sites in the Bay d’Espoir Estuarine Fjord, Newfoundland

2000 ◽  
Vol 34 (1) ◽  
pp. 59-67 ◽  
Author(s):  
Michael F. Tlusty ◽  
John E. Hughes Clark ◽  
John Shaw ◽  
Vem A. Pepper ◽  
M. Robin Anderson
Keyword(s):  
Sediment Cores ◽  
Sediment Quality ◽  
Organic Matter Content ◽  
Matter Content ◽  
Sediment Characteristics ◽  
High Resolution Images ◽  
Sonar Images ◽  
Scale Characterization ◽  
Finfish Aquaculture

Current and potential salmonid aquaculture sites in the Bay d’Espoir estuarine fjord on the south coast of Newfoundland were surveyed using multibeam SWATH sonar. In 1997, shallow sites were surveyed using the CSS Puffin EM3000POS/MV system, and deeper sites were surveyed in 1998 using the CCGS Creed hull mounted EM 1000. Sediment cores from representative areas were collected during this period and analyzed for organic matter content, and pore water ammonium and sulfate. We discuss the correlation between the sediment core profiles and the results of the side scan and sun-illuminated bathymetric imagery. Bay d’Espoir is a natural depositional area, and that, coupled with the unique backscatter properties of fish farm wastes, increases the difficulty of interpreting these multibeam sonar images. A fairly accurate broad scale characterization of sediment quality can be made from high-resolution images. However’, much of the fine scale detail and inherent variation of sediment characteristics associated with impacts from aquaculture cannot be determined from multibeam imagery.

Production and characterization of a traceable NORM material and its use in proficiency testing of gamma-ray spectrometry laboratories

2018 ◽  
Vol 134 ◽  
pp. 45-50
Author(s):  
H. Wiedner ◽  
J. Riedl ◽  
F.J. Maringer ◽  
A. Baumgartner ◽  
M. Stietka ◽  
...  
Keyword(s):  
Proficiency Testing ◽  
Gamma Ray ◽  
Gamma Ray Spectrometry

scholarly journals Preliminary studies on the spatial distribution of artificial 137Cs and natural gamma radionuclides in the region of the Ojców National Park, Poland

Nukleonika ◽  
2018 ◽  
Vol 63 (4) ◽  
pp. 105-111
Author(s):  
Marcin Stobiński ◽  
Filip Jędrzejek ◽  
Barbara Kubica
Keyword(s):  
Spatial Distribution ◽  
National Park ◽  
Background Radiation ◽  
Natural Radionuclides ◽  
Organic Matter Content ◽  
Matter Content ◽  
Gamma Ray Spectrometry ◽  
Strong Positive Correlation ◽  
Local Climate ◽  
Natural Gamma

Abstract The aim of the research is to obtain preliminary information about the spatial distribution of gamma radionuclides in the soils taken from the Ojców National Park with emphasis on the behaviour of artificial radionuclides, with 137Cs as a representative. The natural radionuclides 40K, 226Ra (uranium series), and 228Th (thorium series), which are considered as background radiation, were also determined. In total, 18 soil samples were collected during the summer periods in 2015-2017, while the sampling points were selected with respect to differences in rainfall and local topography gradient. The method was based on gamma-ray spectrometry performed on high-purity germanium (HPGe) gamma detector (relative efficiency 34%). 137Cs was mostly deposited in the top soil layers, with activity in the range of 27.9÷586.6 Bq·kg-1. We found strong positive correlation of the 137Cs activity with the soil organic matter content, and at the same time, its dependence on the rainfall amount. Consequently, the soil types and local climate can control the spatial distribution of 137Cs on a small spatial scale. The quantity of natural radionuclides was highly similar in all samples with the following mean values: 38.0 Bq·kg-1for 228Th, 33.1 Bq·kg-1for 226Ra, and 479.9 Bq·kg-1for 40K.

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