Liliana Pena Naval

Tratamento de água de reservatórios por dupla filtração, oxidação e adsorção em carvão ativado granular

This study evaluated the treatment of raw lake water using a double filtration (DF) pilot plant consisting of an up-flow gravel filter (UGF) in series with a down-flow sand filter (DSF) and followed by a post-treatment granular activated carbon (GAC) unit. Additionally, the study examines the effect of pre and inter-oxidation (between UGF and DSF) on overall efficiency in the treatment and the formation of halogenated organic byproducts (HOB). According to the results obtained, it was observed that the pre-oxidation improved the quality of the UGF effluent and the inter-oxidation favored lower values of turbidity and color in the DSF effluent. Also, the treatment process by adsorption on granular activated carbon, used as a post-treatment, was efficient to ensure the quality of final effluent in the tests, especially regarding the removal of organic matter, cyanobacteria, and color. The maximum concentrations of HOB found in the effluents from the DSF and GAC did not exceed the limits of the Brazilian drinking water standards (Portaria no 2.914/2011).

Características gerais da composição química de mananciais da planície do Araguaia

This study aimed to investigate the general characteristics of the chemical composition of waters of the Araguaia floodplain, in this case ionic balance and classification of water bodies under study into general categories. The study was conducted on the Araguaia Plain (Tocantins). In each of the sources under study a collection point was placed where samples were taken for analysis of concentrations of major ions (Ca, Mg, Na, K, Cl, SO4, HCO3 ), dissolved organic carbon (COD) and dissolved inorganic carbon (CID). The interpretation of the data obtained showed that the values of the concentrations of most elements analyzed were statistically similar between the Javaés and Araguaia rivers during the rainy season. However, during the dry period, when there is no influence of bioleaching processes, the concentrations were statistically different. This behavior indicates that the terms of use and occupation developed in the area of influence of the river Javaés currently do not show changes in the studied region. It was also found that the biogeochemistry of lake Chave is significantly influenced by its connection with the seasonal river Javaés, which indicates that the occurrence of changes in the waters of this river may disturb the lentic environments of the region. Key-words: Araguaia floodplain, biogeochemistry, ionic