MELINA S. HALL, GISSELE O. MONTENEGRO, GLAUCO R. BETEMPS, BERNARDO S. VAZ, PEDRO J. SANCHES FILHO*
*Corresponding author
Instituto Federal Sul-Rio-Grandense, Campus Pelotas
Praça Vinte de Setembro, 455 CEP 96015-360 – Centro, Pelotas – RS, Brazil

Abstract

The pollution in aquatic environments can be indicated by high concentrations of PAHs. This study is aimed to evaluate the possible sources of contamination of PAHs in the São Gonçalo channel sediments collected from the areas of receipt rainwater systems. It was possible to identify sources of contamination and hydrocarbon levels in points studied. The PAHs concentrations found were considered relatively high, in the point located within the Pepino Channel, near the arrival at the São Gonçalo Channel, confirming the impact of urban runoff in the city’s drainage system and how and its consequent impact on water resources.

INTRODUCTION
The São Gonçalo channel is located in the city of Pelotas in Rio Grande do Sul state and is considered as one of several contaminants entry point coming from human actions (1). The urban areas rely on the system of runoff canals to capture rainfall water that promote urban runoff, process dragging contaminants that include various organic and inorganic compounds, mainly from the traffic of vehicles for along the canals, streams and rivers (2).
PAHs are contaminants that enter the water column carried by the urban runoff, incorporating to particulate matter in the organic matter (3) they end up being deposited in the bed of these sites, adding up the bottom sediments, which act as a reservoir for the hydrophobic contaminants (4) and can provide sources of petrogenic, pyrolytic, biogenic an diagenesis of sedimentary organic material (5). The finer sediments (silt + sand) generally contain PAHs (6) and properties as pH, conductivity and dissolved organic carbon control the solubility of these contaminants (7). PAHs have characteristics like hydrophobicity and low reactivity to the environment (3). These are currently classified by ...