Determinação e avaliação da distribuição, fonte e risco ecológico de contaminantes inorgânicos e orgânicos em matrizes ambientais do Rio Capivara, Camaçari-Bahia

Abstract

In this work, analytical strategies for determining and quantification of organic (PHA) and inorganic (metals and metalloids) contaminants were employed in different environmental arrays of the Capivara river, located in Camaçari. Also, the assessment of the distribution, sources and the ecotoxicological risks of contaminants were carried. In surface water samples were determined the elements: Ba, Cu, Fe, Pb, Ni, V, Sb and As employing the ICP-MS. In the sediment samples were identified and quantified of 18 inorganic compounds (Al, As, Ba, Cd, Co, Cu, Cs, Fe, La, Mn, Ni, Pb, Se, Sr, Ti, U, V e Zn) employing the ICP-MS and ICP-OES and 23 organic compounds, the considered priority by the US EPA and 7 alkylated compounds such as methyl-naphthalene, dimethyl-naphthalene, methyl and dimethyl phenanthrene, methyl pyrene, benzo (e) pyrene and perylene employing GC-MS. The possible origin of metals and metalloid was estimated through the enrichment factor (EF) and geochemical index (Igeo) while organic contaminants estimated through the study of molecular reason. The first were stemming from natural processes such as rock weathering and soil erosion, and the second mostly originating in pyrolytics processes, such as the combustion of biomass and refined petroleum products. The SVA/MES methodology enabled the evaluation of the bioavailability of metals Cd, Cu, Ni, Pb and Zn that indicated a low potential of adverse effects. The eco-toxicological risks have been examined by the international and national environmental quality guidelines through the resolutions nº 357/2005 and 454/2012 of the CONAMA and US EPA. All analyzed compounds were below of the threshold, denoting a low risk to local biota. No evidence of contamination were found in the water and sediment samples of the Capybara River.