Eletrosmose aplicada à remediação de solos contaminados com derivados da indústria de petróleo.

Abstract

The aggressions committed to the environment, are frequently, represented by the contamination of the ground with substances derived from oil, which are deposited accidentally or intentionally. Between the products more frequently founded, the organic solvents appear with frequency and intensity due to the wide use of these compounds by the inks and vanishes industries. The toluene and Xilene, compounds with high solvency power are recommended for a varied gamma of applications. When deposited in the environment, they presents average ambient persistence and tending to evaporate if the contamination will be superficial, however, their presence in the subsurface compromises the integrity of the ecosystem and represents a great risk of groundwater contamination. In this case, the decontamination becomes necessary. Although to exist many remediation techniques for soil decontamination, the electrochemical process is the only adjusted to the complex geologic conFigura tions, of fine granulometry and low hydraulic conductivity, which is the typical case of argillaceous ground. The present work present results obtained from electrochemical processing applied in argillaceous soil contaminated with toluene, Xilene and gasoline from electrodes of DSA® (cathode and anode) inserted directly in the ground, being observed the influence of the following parameters on the process: initial humidity of the ground, time of processing and concentration of the contaminant. The results had been evaluated in terms of the displacement of the fluid and the development of the boundary pH in the interelectrodic distance. It was proved that the electric field provokes the variations of pH (maximum value of 12 near to the cathode and 1,5 near to the anode) and mobility of the interstitial fluid, mobilizing by electroosmosis the organic compound. It is concluded that the process is favored by the increase of applied electric field, low percentages of initial humidity of the ground and for a greater processing time.