Remediation of coastal sandy soils polluted by petroleum leaks

Abstract

The group of pollutants containing benzene, toluene, ethylbenzene and xylene (commonly known as BTEX) is typically related to petroleum leaks. According to the United States Environmental Protection Agency that group of pollutants is one of the most often found in contaminated soils. The remediation technology that is commonly applied to the remediation of soils contaminated with those pollutants is Soil Vapour Extraction (SVE); through the induction of vacuum to the soil matrix, SVE promotes the circulation of air within the soil, conducting the contaminant vapours removed to extraction wells and later to the atmosphere, after convenient treatment. The location of petroleum refineries strongly depends on the requirement of significant amounts of water for process, cooling and steam; besides of that, mainly due to the need of guarantying efficient supply of raw materials and shipping of products, petroleum refineries are usually located in coastal areas, commonly constituted by sandy soils; coastal sandy soils normally have low content of natural organic matter, but high soil water content (SWC) that has an important role on the distribution of the pollutants in the soil phases and, consequently, on the time and efficiency of remediation with SVE. The complete knowledge of that role is extremely necessary to adopt the most efficient strategy for the site remediation, aiming, namely, to preview the remediation time required to reach a defined remediation efficiency imposed by legislation. This work presents the study of the influence of SWC on the remediation of soils contaminated with benzene and xylene using SVE. The main objectives

Removal of Tetrachloroethylene from Aqueous Solutions by Adsorption on Clay Minerals

“…Over the last few decades, several in situ remediation technologies have been proposed for the treatment of polluted groundwater, such as in situ soil flushing by surfactant solutions, in situ biodegradation and using permeable reactive barriers (Bortone et al 2013;Di Natale et al 2008;Vogan et al 1999). However, the design and optimization of an effective groundwater remediation technology is a rather complex process in which both technical aspects and economic considerations must be taken into account (Albergaria et al 2012). Instead of excavation or extraction for aboveground treatment or disposal, tetrachloroethylene contamination has been successfully remediated by chemical treatment or bioremediation (Li et al 2013;Quintelas et al 2011).…”