Análise estatística R-modal e modelo geoquímico inverso no estudo da qualidade da água subterrânea na região metropolitana de Fortaleza-CE

Hydrochemical analyses were made for 250 groundwater samples from Dunes, Palaeodunes, the Barreiras Formation and the Migmatitic Complex, in strategic areas of the Metropolitan Region of Fortaleza, for quality assessment and processes of salinization. With respect to limits of potability, chloride w...

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Detalles Bibliográficos
Autor: Fernandes, Maria Aparecida Belém
Tipo de recurso: tesis doctoral
Estado:Versión publicada
Fecha de publicación:2007
País:Brasil
Institución:Universidade Federal do Ceará (UFC)
Repositorio:Repositório Institucional da Universidade Federal do Ceará (UFC)
Idioma:portugués
OAI Identifier:oai:repositorio.ufc.br:riufc/12385
Acceso en línea:http://www.repositorio.ufc.br/handle/riufc/12385
Access Level:acceso abierto
Palabra clave:Águas subterrâneas
Modelagem matemática
Hidrologia
Hidrogeologia
Descripción
Sumario:Hydrochemical analyses were made for 250 groundwater samples from Dunes, Palaeodunes, the Barreiras Formation and the Migmatitic Complex, in strategic areas of the Metropolitan Region of Fortaleza, for quality assessment and processes of salinization. With respect to limits of potability, chloride was acceptable in 73% of the wells, nitrate in 86% and TDS was below limit in 82%. Piper and Expanded Durov diagrams were used for classification according predomination of ions and also as indicators for their origin. For obtaining more significant informations on the origin, Factor Analysis was applied. It showed that in the major part of the areas the dominant factor (Factor 1) represents sodium chloride from marine aerosol. Reverse Geochemical Modeling with PHREEQC identified internal processes in each of the aquifer systems, showing that ion concentrations in waters vary locally, depending on the lithology. Dissolution and/or precipitation of the minerals calcium carbonate, magnesium carbonate, sylvite, gibbsite, calcium sulfate and contribution from marine aerosol are the predominant geohydrochemical processes. Also cation exchange of the types CaX2, MgX2, NaX e KX was identified in the waters from different storages. In the Migmatitic Complex ion concentrations are influenced by the presence of aluminum silicates through dissolution or precipitation of biotite, Na-montmorillonite, kaolinite and Camontmorillonite.