Characterization of Chemically Modified Graphite Paste Electrode by Cork and Study of its Applicability in Quantification of Pb2+ Ions in Produced Water
Electroanalysis. Chemically modified electrodes. Cork. Produced water. Heavy metals. Graphite.
The water produced in the oil fields has a variable composition, depending on factors such as the age of the well and the geological characteristics of the source basin. However, the presence of several organic and inorganic substances with a high potential for toxicity is common to these effluents generated in the oil industry, and represents a serious environmental problem, since, depending on the destination given to them (reinjection, disposal or other purpose), there may be contamination of water bodies, air, soil, as well as bioaccumulation through the food chain: among these contaminants, heavy metals can be listed. In order to meet the parameters established by law and aiming at reducing the environmental damage that can be caused by these substances, monitoring techniques need to be studied. In this sense, voltammetry presents itself as a promising option for the quantification of trace metals in situ. That said, the objective of this work is to characterize the electrodes of graphite paste chemically modified with cork (GrRAC and GrRGC) and test their applicability in the quantification of Pb2 + ions in water produced from an offshore oil field located in Rio Grande do Norte. The efficiency of the synthesized electrodes was also evaluated according to the variation in the mass ratio between graphite powder and powdered cork. The electroanalytical techniques used were: Cyclic voltammetry, differential pulse voltammetry, square wave voltammetry and electrochemical impedance analysis.