Remoção de HPA de Água Produzida Utilizando Sistema Microemulsionado
Produced water, PAH, microemulsions, surfactant
The produced water is the largest volume of liquid generated during production and processing of petroleum and natural gas and its composition can contain several toxic compounds, among them there are the polycyclic aromatic hydrocarbons (PAH), whose presence causes harmful effects to the environment. This paper discusses a study on the removal of 15 PAH in produced water using microemulsions systems. For this, it was developed a pseudoternary phase diagram consisting of produced water enriched with PAH, as the aqueous phase (AP), n-hexane as oil phase (OP) and n-butanol and CTAB as cosurfactant (C) and surfactant (T), respectively, to a ratio C/T = 4. From the construction of the diagram, in the region of interest, Winsor II (WII), was chosen a spot with a high percentage of AP to test treatment. This spot (90% AP, 5% and 5% OP C/T) was evaluated in two ways: using a precursor of microemulsion formation with the AP and the active matter and microemulsion formed at that spot. The qualitative assessment, carried out by means of fluorescence spectroscopy, showed that there was water treatment for both methods, however, the quantitative assessment, carried out by means of high performance liquid chromatography with fluorescence detector (HPLC-FLD), showed that extraction using microemulsion was more efficient. Thereby, it was performed a simplex centroid experimental planning so that the study of the influence of the phases were measured, and thus it was possible to identify the great spot of extraction. The samples were analyzed by HPLC-FLD and its results showed that each PAH presented a different response surface, however all of them showed a maximum extraction at the microemulsion spot with 90% AP, 5% OP and 5% C/T composition. This result shows that this technique is promising for the produced water treatment in removing PAH, constituting an alternative to the treatment of this reject.