A facile acid induced water-based solvent by improving hydrophobicity for simultaneous remediating total petroleum hydrocarbon, heavy metals and benzo(a) pyrene contaminated soil: Laboratory- and pilot-scale studies

Molecular DFT Investigation on the Inclusion Complexation of Benzo[a]pyrene with γ-Cyclodextrin

“…The toxic equivalency factor (TEF) makes it possible to evaluate the toxicity of PAHs that have poor toxicological data on the carcinogenicity with quantitative estimates of their carcinogenic potency expressed relative to that of BaP, this allows to analyze their presence in food webs and to attribute a biological significance to their concentrations measured in tissues; [17,18] the presence of benzo[a]pyrene has been identified in a wide range of environmental and combustion-related samples such as cigarette smoke, sediment, air particulate, water, coal tar, crude oil, and diesel particulate, [19,20] and tend to persist in the environment partly and accumulate in soils due to its high hydrophobicity and its strong adsorption onto the soil organic matter, these properties make biodegradation or chemical treatments of BaP very difficult. [21,22] Among the methodologies developed to extract, treat or analyze BaP and other PAHs are the use of cyclodextrins (CDs); [23,24] that are cyclic oligomers composed of six, seven or eight glucopyranose units which are commonly available in three types α-(alpha), β-(beta) and γ-(gamma) and presenting enclosed cavities approximately of 4.7-5.3, 6.0-6.5, and 7.5-8.3 Å in diameter, respectively. The external part of the cyclodextrins is hydrophilic whereas the interior cavity is hydrophobic enabling them to entrap guest molecules in their molecular cavities, thus allowing remarkable effects in stabilizing and solubilizing lipophilic unstable substances without the formation of chemical bonds and without changing their structure; such physical interaction can be considered as an encapsulation of substances at a molecular scale via non-covalent interactions.…”