Extraction agents for the removal of polycyclic aromatic hydrocarbons (PAHs) from soil in soil washing technologies

Could saponins be used to enhance bioremediation of polycyclic aromatic hydrocarbons in aged-contaminated soils?

“…Surfactants form micelles 117 (aggregates of monomers) above a defined concentration called critical micellar concentration 118 (CMC) [Lakra et al, 2013]. This surfactant property has been widely investigated over the last 119 decades in order to use surfactants in soil "washing technologies" [Von Lau et al, 2014] or to 120 increase mass transfer of contaminants towards degrading cells [Kobayashi et al, 2012] byincreasing the apparent solubility of PAHs in water. Finally it is noteworthy that when solid 122 phases such as soil are present; surfactants can also aggregate into structures that adsorb onto 123 particles.…”

“…Furthermore, PAHs present multiple health-86 concerning properties such as mutagenicity, carcinogenicity or teratogenicity, explaining why 87 they have been of major concern [Zhang et al, 2006]. They are classified in two main categories: 88 the low molecular weight PAHs, including molecules bearing three rings or less (naphthalene, 89 acenaphtene, fluorene, phenanthrene, and anthracene) and the high molecular weight PAHs, 90 including molecules of four rings or more (fluoranthene, pyrene, benzo(a)anthracene, chrysene, 91 benzo(b)fluoranthene, benzo(k)fluoranthene, benzo(a)pyrene, dibenzo(ah)anthracene, 92 benzo(ghi)perylene, and indeno(123-c,d)pyrene) [Megharaj et al, 2001; Von Lau et al, 2014]. 93…”

Biosurfactant from red ash trees enhances the bioremediation of PAH contaminated soil at a former gasworks site

“…PAHs have been successfully been 'washed' from contaminated soils with solvents including synthetic surfactants (Lau et al, 2014), peanut oil, vegetable oils (Gong et al, 2005) and cyclodextrins (Viglianti et al, 2006). These techniques have been shown to be satisfactory; however, they tend to require significant post-removal clean-up and in the case of thermal treatment the soil is potentially left with limited nutrients and devoid of microbial life (Gan et al, 2009).…”

Dynamic and static radiation scattering in a microemulsion as a function of dispersed phase concentration

“…In materials science they have been used to obtain both organic and inorganic nanoparticles [3][4][5][6] and some systems have successfully been used in enhanced oil recovery [7]. In environmental applications (more specifically in soil remediation), they can be used to wash out polycyclic aromatic hydrocarbons [8] and have intensely been used/suggested for pharmaceutical formulations destined to controlled release of bioactive agents [9]. It has also found its place in analytical chemistry: microemulsion electrokinetic chromatography (MEEKC) has been proven to be both http://dx.doi.org/10.1016/j.colsurfa.2014.…”