Estudo da precipitação sazonal na qualidade das águas na área de influência do lixão de Salinópolis, PA

Abstract

The rainfall directly influences in the physicochemical and microbiological water bodies composition through complex processes of surface-atmosphere interaction. However, the quality of a water body does not depend only on natural factors, anthropic influence is an important variable to be considered for the analysis of water quality. The water quality is critical to the maintenance of the environmental balance and the health of the population who uses it. Although, many studies emphasize the quality of water in dumps and landfills, assessments that relate hydrologic variables with physicochemical parameters are still scarce, especially in the Amazon region. The objective of this study was to investigate the role of seasonal precipitation in the quality of surface water and groundwater near the landfill in Salinópolis, located in the village of Cuiarana through the characterization of rainfall in the region and its influence on the physicochemical and microbiological composition of the local waters. For this, we obtained the precipitation climatology of Cuiarana and data of the monthly accumulated precipitation for the period of 2014-2015 through the CMORPH technique, infiltration rate measurement on the ground in March and October 2015, and flow measurement of the rivers Cachoeira and Teixeira in March 2015. For the physicochemical and bacteriological analysis, we selected the following parameters: pH, dissolved oxygen, water temperature, total dissolved solids, turbidity, conductivity, salinity, ammonia, nitrate, nitrite, total coliforms, and Escherichia coli; and the metals: aluminum, cadmium, lead, copper, chromium, iron, manganese, mercury, nickel and zinc. Both surface and groundwater presented unsuitable for use and human consumption. Parameters such as dissolved oxygen, iron, aluminum, lead, mercury, total coliforms and E. coli are in violation of the current legislation, for both surface and groundwater. The rainy season affected negatively the quality of the surface water, while dry period was more important to the groundwater quality deterioration. The region near the dumpsite showed greater vulnerability to a progressive deterioration of the quality of surface and groundwater, since the junction of factors such as high speed of water infiltration into the soil, topography and rainfall allow the dispersion of pollutants arising from the dump towards water bodies.