Sorption of chlorinated hydrocarbons from synthetic and natural groundwater by organo-hydrotalcites: Towards their applications as remediation nanoparticles

Removal of recalcitrant compounds from water using synthetic hydrotalcites

“…An increase in TCE concentration (up to 525 mg/L) did not affect PFOS or PFOA sorption capacity (Figure 4.21a), thus there is little indication for any competitive sorption. This may not be unexpected because nonionic species (e.g., TCE) are only sorbed by HT via solute partitioning and their uptake is enhanced when HTs exhibit an organic interlayer, i.e., surface properties become more hydrophobic (Alonso- de-Linaje et al, 2019;Ruan et al, 2013;You et al, 2002;Zhao and Nagy, 2004). It is hypothesized that the HT interlayer is modified towards a more hydrophobic compound with the intercalation of PFOS and PFOA, which could eventually enhance the sorption of non-ionic contaminants such as TCE.…”

“…The PXRD spectra of the initial, unexposed, HT with intercalated dodecyl sulfate -de-Linaje et al, 2019;Clearfield et al, 1991). The FT-IR showed characteristic HT-DS absorption bands: metal-oxide-metal lattice vibration modes at 800-500 cm -1 , S=O antisymmetric and symmetric stretching at 1220 and 1065 cm -1 , C-H stretching at ~3000 cm -1 and C-H bending modes at ~1469 cm -1 ( Figure 4.28b) (F. .…”

“…The sorption capacity of HT-CO3 and HT-DS towards various pollutants is well known (Rojas, 2012;Ulibarri and Hermosin, 2001), including the impact of varying geochemistry (Alonso- de-Linaje et al, 2019;Chuang et al, 2008;Hu et al, 2017) and pollutant loading (Gillman, 2006;Zubair et al, 2017). However, the current knowledge about the stability of these HT compounds during long-term exposure to natural groundwater is limited.…”

“…Data points represent the average between the analytical data obtained. Modified from Alonso-de-Linaje et al (2019).…”

“…PCE: tetrachloroethylene, TCE: trichloroethylene, VC: Vinyl chloride, 1,1-DCE: 1,1 dichloroethylene, cis-DCE: cis-dichloroethylene, trans-DCE: trans-dichloroethylene, 1,1-DCA: 1,1 dichloroethane, 1,2-DCA: 1,2 dichloroethane, 1,1,2-TCA: 1,1,2-trichlorethane. Modified from Alonso-de-Linaje et al (2019).…”