Evaluating of BTX Removal of Water Contaminated with Gasoline by Fenton Process: Chemical and Ecotoxicity Analysis

This study shows the results obtained of evaluation and comparison of chemical analysis and ecotoxicity for evaluated the quality of water contaminated with gasoline after Fenton process. The process Fenton was efficient to remove the aromatics organic compounds such as benzene, toluene and xylenes from water contaminated with gasoline. At 90 minutes of reaction time, the concentration measured of aromatics compounds by gas chromatography were less than limit of quantification (0.05mg L-1). This value is in accordance with the limits established by Brazilian legislation for the effluents discharge. On the other hand, analysis of total phenols and dissolved organic carbon demonstrated at 120 minutes that all dissolved organic compound and total phenols are not totally removed even though benzene, toluene and xylenes were almost completely removed. Phytotoxicity tests using Sinapis alba as biological response showed that water contaminated with gasoline are not toxic, however these results was probably influenced by volatilization of aromatics compounds during the assay. Differently, the ecotoxicity using Daphnia magna showed that water contaminated with aromatic compounds is toxic, but after 120 minutes of treatment the toxicity was reduced more than 50%. Then, Daphnia magna was the better bioindicator to evaluate the efficiency of Fenton process since these results were according with response of dissolved organic carbon and total phenol showing the toxicity of intermediates produced during the Fenton process.