Abstract

The aims of this work was to quantify the concentration of petroleum aromatic hydrocarbon in the intertidal zone at Boa Viagem Beach (Guanabara Bay, RJ, Brazil) and to determine, by ex situ treatment, the natural attenuation of these substances in the presence of high organic matter content. We determined concentration and degradation of petroleum aromatic hydrocarbon, organic matter, bacterial carbon (CB) and esterase enzyme activity (EST) and electron transport system (ETSA) during 30 days. The results showed that Boa Viagem Beach’s sediment, in the beginning of the assays, had high concentration of aromatic hydrocarbon occurring natural attenuation about 99.9%, when it represented 6.57% of the sediment’s organic matter. The electron transport system activity was significantly different between the bioassays. It is based on dehydrogenase enzymes that are the major representatives of oxido-reductase reactions. This activity could be used as a biomarker to detect the aromatic hydrocarbon and remediation processes. The natural attenuation ex situ occurred in thirty days, and this time is advantageous in the remediation process of aromatic hydrocarbon. These tools can be used in the environmental impact assessment.