Applications of Clay Materials for the Removal of Organic Xenobiotics from Contaminated Waters

Abstract

Clay minerals are one of the most common constituents of soils. Its ubiquity in nature makes this class of materials unsurprisingly one of the most extensively studied groups of adsorbents for organic pollutants (Dordio and Carvalho, 2013) . In fact, because of this high potential for ion exchange and surface interactions, in addition to the extensive sorption capacities resulting from their large surface areas (due to the sheet structure of these minerals) clays act as natural scavengers of pollutants (Akcay and Yurdakoc, 2000; Dordio et al., 2007; Dordio et al., 2009; Srivastava et al., 2009; Iglesias et al., 2010; Park et al., 2011; Dordio and Carvalho, 2013) . For such reasons, and adding to their wide availability and associated low cost, in recent years there has been an increasing interest in utilizing natural, processed or chemically-modified clays for the removal of contaminants from aqueous solutions. The aim of this work is to present a review on the extensive amount of studies on the adsorption of organic compounds to several materials of this type. The discussion is focused on the environmental applications, specifically for the decontamination of water and wastewater polluted with organic xenobiotics, and with the aim of providing resources for the screening of materials with potential to be used as efficient and economic water and wastewater treatment alternatives.