Estudo das concentrações de metais pesados em áreas que recebem efluentes industriais - caso do Furo do Maguari, Distrito de Icoaraci, Belém-PA

Abstract

The Maguari Hole, located in the Guajarino estuary, in the state of Pará, represents an important ecosystem located near the urban area of the city of Belém and, as such, subject to the accumulation of various types of waste and industrial processes, accentuated by an intense and disorganized process of urban expansion, where several housing developments and residences were implanted on the banks of the Maguari River and important secondary courses (igarapés), with intense boat traffic. The main industrial activities in this region are fishing, lumbering, fertilizer manufacturing, leather tanning, etc., adding the clandestine extraction of clay and sand. The present study discusses the transport and geochemical behavior of anthropogenic and naturally occurring heavy metals (Fe, Zn, Mn, Cr, Ni, Co, Cu, Cd and Pb) in the Furo do Maguari basin, in the following environments: in the waters, bottom sediment and margin of the Ananin and Píraíba streams and other points in Furo do Maguari. The samples were collected by seasonal sampling in the streams, floodplain soils, and mangroves during the rainy and dry seasons, during flood and ebb tides, for a total of two samples. The metals were analyzed in particulate and dissolved phases, in bottom sediments of the channels and on the banks by auger sampling. The main phase of metal transport is the particulate phase, where we found that Fe, Mn, and Zn are strongly correlated, and these associations persist in the bottom sediments and in deep-sea profiles, associated with iron-oxidehydrate phases. The element chromium (Cr) drew most attention due to its high concentration in the streams mentioned above, having its source in the leather tanning industries.