Quality of water resources in the Amazon region- Rio Tapajós: assessing the case for chemical elements and physical-chemical parameters

Abstract

The Tapajós river is the main rivers of the Pará State and part of the Amazon basin is the largest world river basin, however, the population growth and development of agriculture in the region has generated the input of contaminants in this important river. The objective of this study was to evaluate the water quality of the Tapajós river in the presence of metals and physico-chemical parameters based on the CONAMA 357-05 resolution. Seven sampling stations were selected along the river in the surface, intermediate and bottom layers in low rainfall periods. The elements Ca, Mg, Al, Fe, Ba, Mn, Sr, Ti, Ag, Be, Cd, Co, Cr, Cu, Mo, Ni, Pb and Zn were determined using the inductively coupled plasma atomic emission spectrometry (ICP-AES), As was determined by ICP-AES with hydride generation, Hg was determined by cold vapor atomic absorption and the physico-chemical parameters were evaluated using various techniques. In almost all respects the elements Al and Fe are not presented in accordance with the values allowed by Brazilian legislation, with average values of 280.01 ± 294.69 ?g/L and 564.89 ± 326.5 ?g/L, respectively. There were excellent correlations between Ca and Mg, Ca and Sr, Mg and Sr, Mn and Ba, Sr and OD, Mg and OD. The Tapajós River showed high levels of Al and Fe that compromises the quality of this important river of the Amazon and can cause problems for the health of the population.