EFFICIENCY STUDY OF MICROEMULSIONATED SYSTEMS IN THE REMOVAL OF CONTAMINANTS IN PRODUCED WATER
Produced water. Contaminants Removal.Microemulsion systems.
Produced water is a subproduct of oil extraction process and its characteristics vary according to the well producer, bringing up several contaminants whose removal has a very complex treatment process. Thus, this water has been the subject of attention because it can’t be discharged without proper treatment. This study This work aimed to study the behaviour and use of microemulsion systems on the removal of produced water contaminants, as well as the application of the treated water in sunflower germination. It was performed a study of pseudoternaries diagrams, containing in their compositions: produced water enriched with metals (PWD) as aqueous phase (AP), hexane and kerosene as organic phase (OP), ratio co-surfactant/surfactant (C/S = 1 and 4), using six types of surfactants: Renex, Alkonat, coconut oil saponified (COS), sodium dodecyl sulfate (SDS), cetiltrimethylammonium bromide (CTAB) and ultramina; and as co-surfactant n-butanol. After the diagrams development and the choice of the best system, it was performed the process of extraction of contaminants contained in the PWD, by choosing three points located in the Winsor II region, in an area rich in water and a low amount of surfactant, the compositions were termed as maximum point (30% C/S, 10% OP, 60% AP); medium point (17.5% C/S), 7.5% OP, 75% AP); minimum point (5% C/S), 5% OP, 90% AP). For the determination of the concentrations of contaminants (metals, anions and PAHs) different methods of analysis were used, including ICP-OES (Inductively Coupled Plasma Optical Emission Spectrometry), HPLC-FLD (High Performance Liquid Chromatography with Fluorescent Detector) and X-Ray Fluorescent Detector. The system whose obtained higher efficiency of removal was the one containing COS as surfactant, C/S ratio = 4 and hexane as organic phase. The best results of removal of contaminants were in the medium point which composition is (17.5% C/S, 7.5% OP, 75% AP). Finaly, the treated water using this system was applied on sunflower germination, getting satisfactory results on the diluted compositions. This study has shown that the use of microemulsion systems may be an alternative in the correct management of this kind of waste from the petroleum industry, besides the efficient treatment, this treated water can be an alternative in case of reuse in the irrigation process.