Mapeamento de manchas de óleo e graxa na zona portuária de Natal-RN utilizando técnicas de geoprocessamento e análise química de água
Resumo
This work mapped oil and grease stains in the Natal-RN port area in the months of
october, november and december of 2016 year through geoprocessing techniques and
chemical analysis of water samples. The methodology for the development of this work
was divided in three stages: pre-field, corresponding to the bibliographical research
and previous mapping of the points of water collection in the estuary of the Potengi
River; Field, comprising collecting water samples, as well as photographic records of
the study area and observation of liquid effluent disposal without treatment in the fluvial
channel, and post-field, satisfying the laboratory tests, kriging maps and IDW with the
values of the oil and grease content of the samples, integration and interpretation of
data obtained. In all, were collected 90 water samples in the environs of the Port of
Natal, the first thirty were sent to the Nucleus of Analysis of Water, Food and Effluents
of the Federal Institute of Rio Grande do Norte, and the other 60 to the Nucleus of
Processing Primary and Reuse of Produced Water and Residue of the Federal
University of Rio Grande do Norte, identifying the presence of oil and grease and,
consequently, going against existing environmental legislation. As results, using the
NDVI Vegetation Index, it was possible to identify possible plumes of oil and grease
contamination in the Potengi River bed, especially when comparing with the
interpolated maps. Therefore, it is concluded that in the port area of this study oil and
grease were released through laboratory chemical analysis and that 100% of the
analyzed samples indicated oil and grease contents, as well as other physical and
chemical aspects such as turbidity, conductivity and PH, divergent with the current
environmental legislation. In this context, the interpolation and NDVI methods proved
satisfactory to achieve the proposed objectives