Physical and mineralogical characterization of sediments dredged from the access channel of the Port of Rio Grande-RS

Abstract

The Port of Rio Grande, located in the extreme south of Brazil, has had several seasonal dredging operations throughout its history. Maintenance dredging is constantly being performed, which consists of the removal of deposited sedimentary material in order to avoid accumulation. Although there is planning aimed at optimizing dredging operations, a better understanding of the sedimentation processes in the Port of Rio Grande is extremely important. The present work sought to characterize the behavior of the sediments dredged in the maintenance dredging operations in the access channel carried out during the year 2019. Through the determination of physical and mineralogical characteristics of these sediments by laser granulometry, X-ray diffraction analysis and scanning electron microscopy. As a result, the sediment was classified as silty sand, and the fractions of the material present had the percentages of 44.29% sand, 51.96% silt, and 3.75% clay. Through the diffractogram one can see the presence of minerals in the sediment, such as quartz, k-feldspar, illite and kaolinite. And from the scanning electron microscopy it was possible to see some pores in the structure, characterized as preferential paths for water movement.