DISTRIBUIÇÃO DO TAMANHO DE PARTÍCULAS DE SEDIMENTOS DE FUNDO EM RESERVATÓRIO: ESTAMOS MEDINDO REALMENTE O QUE ACREDITAMOS MEDIR?

Código

PAP042

Autores

Luciane Lemos do Prado , Klajdi Sotiri, William Bonino Rauen, Heloise Garcia Knapik, Cristovão Vicente Scapulatempo Fernandes, Luciane Lemos do Prado, Cristovão Vicente Scapulatempo Fernandes

Tema

QUALIDADE DA ÁGUA E SEDIMENTOS EM BACIAS HIDROGRÁFICAS E REGIÕES COSTEIRAS

Resumo

The determination of the size distribution particlesof soils and sediments is of special interest in the study of transport and sediment modeling, sedimentation and silting processes,reservoir dredging, and water quality management. Different techniques can be used for such quantification, whose uncertainties and difficulties depend, among other factors, on the particles heterogeneity of form and density. Thus, the goal of the present study was to evaluate theeffect of organic matter removal and sonication time on the determination of the particle size distribution in a reservoir bottom sediment sample with high fines content.The sample was collected from a 12 m depth core in the central portion of the Passaúna / PR reservoir.The results indicated that the organic matter influencesthe particle aggregation and, consequently, induces larger values of the real particle size. Additionally, considering the samples without organic matter removal, the sonication time showed to be an important variable in the disaggregation process. However, considering the organic matter removal, the increase time of sonication did not produce different results in particle distribution. Thus, for the same sample collected in the field, different procedures regarding the pretreatment indicated different results. Therefore, the uncertainties associated to the application of these procedures are emphasized, especially when studying the characterization of environmental matrices in different monitoring strategies. The uncertainties associated with granulometric characterization may produce impacts on the understanding of the physical and chemical processes associated with its characteristics.