Dynamics of Heavy Metals in the Waters of Iqarape do Quarenta: The Water Body that Crosses the Industrial Hub in the Brazilian Amazon.

Abstract

This study aimed to characterize an important body of water that crosses the industrial pole of Manaus – Igarapé do Quarenta, in Amazonas, and to evaluate possible sources of heavy metals in these waters. It is known that the anthropogenic and industrial influence is very intense in these waters, which significantly increases the levels of heavy metals. The results showed that the waters of the Quarenta stream are close to neutrality (pH from 6.87 to 7.03), which contradicts the acid values characteristic of the region. The electrical conductivity values exceeded 300 μS cm 1, which places the electrolyte charge of these waters almost 20 times higher than the natural values. Among the heavy metals studied, the highest contents were for Fe and Mn, whose concentrations were higher than those established by legislation. Along the Quarenta stream, sinks of heavy metals can be seen, probably due to the phenomenon of dilution or precipitation of these materials. The PLI demonstrated that there is a large polluting load of Pb, Cd, Cu and Mn. The HCA study showed associations between Mn – Fe, Cu – Cd, Ni -Pb and Cr – Zn, which reflect biogeochemical processes being altered by anthropogenic factors. Finally, PCA informs that pH and electrical conductivity inversely influence the concentrations of Zn and Cd and that Ni is the most representative metal in the dataset.