ELECTROKINETIC REMEDIATION OF CARBONIFEROUS SOIL POLLUTED WITH PETROLEUM
Remediation, soils, carboniferous, petroleum, decontamination
This work was carried out with the purpose to test the application of electrokinetic treatment and behavior of its phenomena (electromigration, electro-osmosis, electrophoresis and electrolysis) in the decontamination of soils contaminated by xenobiotic components. To do this, a set of experiments to determine the best cell geometry and dimensions were performed to find the best operating conditions for using as pilot plant. The experiments were performed in cells with different internal volumes ranging from 0.1 L to 3 L, favoring the development of a cell with better yield for the final experiments. In both experiments developed the carboniferous soil was contaminated with different concentrations of crude oil from Umburana natural reservoir, ranging from between 500 ppm to 2500 ppm, thus constituting contaminated sediment matrix. For configuration of the sample used, an amount of soil ranging from 0.05 kg to 1.5 kg was used. A set of experiments were discussed in three main divisions; Preliminary experiments, experiments intermediate and final experiments in which consolidated a methodology for Electrokinetic Remediation of Soils (RES) with higher yield. Electrodes employed were dimensionally stable anodes (DSA) of ruthenium-titanium-oxide (Ti / Ru0,34Ti0,66O2) and graphite (GC) by applying different electrical currents. The removal of organic compounds was monitored by Total Organic Carbon (TOC), Zeta potential (ζ) and spectrophotometric measurements (UV-Visible). Also, measurements of hydrogenionic potential (pH), conductivity (S.cm-1) and the volume of vaporization of the electrolyte used (Na2SO4), were performed. The results indicated that over 70% of oil products were removed from the soil after 384 h. In 480 h test was verified higher removal of organic pollutants in cathodic and anodic compartments; and also in the presence of heavy metals. The zeta potential showed that the organic compounds are transported due to the phenomena of electromigration and electro-osmosis, and confirming that the particle size varies in function of time. The electrolysis of electrolyte favors the formation of a pH gradient, which allowed an increase in mobility of soil contaminants to the reservoirs. The effluent contaminated with oil was also treated electrochemically, obtaining high removal levels.