Potencial de aplicação da filtração em margem em Santa Catarina, Brasil

Bank filtration (BF) consists in getting water from wells or springs located on an aquifer in hydraulic contact with a surface water source. Through literature search the main conditions for the implementation of the BF were identified. These include the availability of surface water and groundwater in hydraulic connection, the hydro-geology of the aquifer, hydrology of the water body, river morphology, composition of the river bottom and the quality and temperature of the local surface water and groundwater. Based on these characteristics and using the Hydrogeological Atlas of Brazil in GIS environment, the places with potential for BF application in the state of Santa Catarina were determined. The main regions with potential for BF consist of alluvial and coastal deposits, located mainly in coastal areas. The information was collected in a thematic map delineating the alluvial formations and the coastal deposits comprising 1557 and 3113km² respectively. According to the study, 4.88% of the state of Santa Catarina has potential for BF. However, the success of BF depends largely on the specific location and it is necessary to verify the applicability on the site. As an example, the case of Lagoa do Peri in Santa Catarina is presented, where BF was successfully implemented on a pilot scale. The water presented reduction in turbidity, apparent color, organic matter and phytoplankton, including cyanobacteria. However, it presented anoxic conditions, which require a post-treatment by aeration and filtration to remove iron and manganese which are undesirable in drinking water.