Avaliação da qualidade da água e sedimentos superficiais da rede fluvial do Município de Azambuja
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Data
2023
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O presente estudo pretende ampliar a área dos estudos de monitorização da qualidade da água
e sedimentos fluviais iniciados na região do município de Azambuja, desde 2018, que se têm
centrado principalmente no Paul de Manique do Intendente e na bacia hidrográfica onde este se
encontra instalado (ribeira do Judeu). Considera-se importante salientar a falta de estudos
científicos publicados no local, deste modo, este estudo visa caracterizar pela primeira vez, e
de um modo geral, a área de estudo.
A monitorização abrangeu a totalidade das linhas de água da área geográfica de Azambuja, com
destaque para as ribeiras de Aveiras, Valverde e Maçussa. O estudo pretendeu efetuar uma
caracterização físico-química e microbiológica das águas superficiais e uma análise textural e
composicional dos sedimentos fluviais. Para alcançar estes objetivos, foram delineadas bacias
hidrográficas, identificadas possíveis fontes de poluição, estabelecido um plano de amostragem,
realizadas duas campanhas de campo e trabalho de laboratório.
A caracterização físico-química das águas foi realizada com recurso a sondas multiparamétricas
(medições in situ), a caracterização microbiológica e a análise dos sedimentos foram realizadas
em laboratório com recurso a diferentes metodologias.
Os resultados físico-químicos revelam águas maioritariamente Oligahalinas (elevada
condutividade), maioritariamente alcalinas, com zonas com escassez de oxigénio ou com
sobressaturação, associados a pontos com contribuição orgânica visualmente evidente.
Salienta-se com os piores resultados as ribeiras de Valverde e a de Aveiras.
Os resultados microbiológicos indicam águas com baixa qualidade, com contaminação
maioritariamente de origem fecal humana. Foram identificados apenas dois pontos aptos para
uso balnear (carecem de aprovação) e três para rega. Em comparação com estudos anteriores,
os resultados do presente estudo revelam valores mais elevados. Salienta-se com os piores
resultados as ribeiras de Valverde e a de Aveiras.
Os parâmetros sedimentológicos permitem verificar que os sedimentos fluviais são
maioritariamente arenosos (areias grosseiras e mal calibradas), enriquecidos em componente
vasosa com teores de matéria orgânica superior a 5%, com componente carbonatada. A nível
mineralógico, maioritariamente quartzos, angulosos, superfície pouco limpa e componente
orgânica variada. Sugere-se a mitigação da poluição por efluentes domésticos, agrícolas e
industriais, monitorização das águas e sedimentos e formação/sensibilização da população.
Palavras-chave: Qualidade, parâmetros microbiológicos, água, sedimentos, poluição
The present study intends to expand the area of monitoring studies of water quality and river sediments started in the region of the municipality of Azambuja, since 2018, which have focused mainly on Paul de Manique do Intendente and the hydrographic basin where it is located (Ribeira do Judeu). It is considered important to point out the lack of scientific studies published on the site, therefore, this study aims to characterize for the first time, and in general, the study area. Monitoring covered all the water lines in the geographical area of Azambuja, with emphasis on the Aveiras, Valverde and Maçussa streams. The study intended to carry out a physical chemical and microbiological characterization of surface waters and a textural and compositional analysis of river sediments. To achieve these objectives, watersheds were delineated, possible sources of pollution were identified, a sampling plan was established, two field campaigns and laboratory work were carried out. The physical-chemical characterization of the water was carried out using multiparametric probes (in situ measurements), the microbiological characterization and the analysis of the sediments were carried out in the laboratory using different methodologies. The physical-chemical results reveal waters that are mostly Oligahaline (high conductivity), mostly alkaline, with areas with oxygen shortage or supersaturation, associated with points with visually evident organic contribution. The Valverde and Aveiras rivers stand out with the worst results. The microbiological results indicate low quality water, with contamination mainly of human fecal origin. Only two points suitable for bathing were identified (need approval) and three for irrigation. Compared to previous studies, the results of the present study reveal higher values. The Valverde and Aveiras rivers stand out with the worst results. The sedimentological parameters allow verifying that the fluvial sediments are mostly sandy (coarse and poorly calibrated sands), enriched in a muddy component with organic matter contents greater than 5%, with a carbonate component. At the mineralogical level, mostly quartz, angular, poorly cleaned surface and varied organic component. It is suggested the mitigation of pollution by domestic, agricultural and industrial effluents, monitoring of water and sediments and training/awareness of the population. Keywords: quality, microbiological parameters, water, sediments, pollution.
The present study intends to expand the area of monitoring studies of water quality and river sediments started in the region of the municipality of Azambuja, since 2018, which have focused mainly on Paul de Manique do Intendente and the hydrographic basin where it is located (Ribeira do Judeu). It is considered important to point out the lack of scientific studies published on the site, therefore, this study aims to characterize for the first time, and in general, the study area. Monitoring covered all the water lines in the geographical area of Azambuja, with emphasis on the Aveiras, Valverde and Maçussa streams. The study intended to carry out a physical chemical and microbiological characterization of surface waters and a textural and compositional analysis of river sediments. To achieve these objectives, watersheds were delineated, possible sources of pollution were identified, a sampling plan was established, two field campaigns and laboratory work were carried out. The physical-chemical characterization of the water was carried out using multiparametric probes (in situ measurements), the microbiological characterization and the analysis of the sediments were carried out in the laboratory using different methodologies. The physical-chemical results reveal waters that are mostly Oligahaline (high conductivity), mostly alkaline, with areas with oxygen shortage or supersaturation, associated with points with visually evident organic contribution. The Valverde and Aveiras rivers stand out with the worst results. The microbiological results indicate low quality water, with contamination mainly of human fecal origin. Only two points suitable for bathing were identified (need approval) and three for irrigation. Compared to previous studies, the results of the present study reveal higher values. The Valverde and Aveiras rivers stand out with the worst results. The sedimentological parameters allow verifying that the fluvial sediments are mostly sandy (coarse and poorly calibrated sands), enriched in a muddy component with organic matter contents greater than 5%, with a carbonate component. At the mineralogical level, mostly quartz, angular, poorly cleaned surface and varied organic component. It is suggested the mitigation of pollution by domestic, agricultural and industrial effluents, monitoring of water and sediments and training/awareness of the population. Keywords: quality, microbiological parameters, water, sediments, pollution.
Descrição
Orientação: Anabela Cruces
Palavras-chave
MESTRADO EM ENGENHARIA DO AMBIENTE, CIÊNCIAS DO AMBIENTE, ENVIRONMENTAL SCIENCES, ENGENHARIA DO AMBIENTE, ENVIRONMENTAL ENGINEERING, QUALIDADE DA ÁGUA, WATER QUALITY, MONITORIZAÇÃO AMBIENTAL, ENVIRONMENTAL MONITORING, SEDIMENTOS, SEDIMENTS, POLUIÇÃO, POLLUTION, POLUIÇÃO DAS ÁGUAS, WATER POLLUTION, CONTROLO MICROBIOLÓGICO, MICROBIOLOGICAL CONTROL