Análise espaço-temporal de elementos maiores e variáveis físico-quimicas em um trecho do Rio Solimões – Amazonas

Abstract

This study aims to contribute for a better understanding the chemical dynamics and interactions species Na, Ca, K and Mg along Solimões-Amazon River, taking into account Cl-, SO42- and NO3- concentration, hydrogen potential (pH), electrical conductivity (EC) and total organic carbon (TOC) in surface water samples collected in May, July and September 2012 at eight points in the Solimões-Amazonas river and at the some major tax mouth: Jutaí, Juruá Japurá, Purus and Madeira rivers in the Amazonas state. Chemical analyzes were performed at the Environmental Chemistry Laboratory (LQA) of Environmental Dynamics Coordination in the National Institute for Amazonian Research (CEDAM-INPA). Chemical elements and anionic species were analyzed by ion chromatography. Hydrogen potential and alkalinity by potentiometry, electrical conductivity by conductometry and TOC by catalytic oxidation combustion. The average concentrations of the elements followed the order Ca2+>Na+>Mg2+>K+ and anions SO42 ->Cl->NO3-. With exception TOC and K+ a decreasing trend in the variables values over the course of the river, partly caused by the inflow of tax was observed. The multivariate statistical analysis PCA and HCA had a good level of agreement, sorting the sample points of the Solimões River in accordance with the sampling times and location, distinguishing the different periods in which samples were collected and the points located upstream and downstream of the river.