Cotransport of fullerene nanoparticles and clay colloids in porous media: The relation between aggregation and transport.

In the study, cotransport of fullerene nanoparticles (nC) and mobile clay colloids (illite (ILL), kaolinite (KL), montmorillonite (ML)) in aquifer porous media and its relation to the aggregative interaction between these two types of particles was investigated. Minimal interaction occurred between nC and ILL, resulting in unaffected transport. Strong heteroaggregation between ML and nC resulted in not only significant retention of both particles during their cotransport but also the retention of nC in the media pre-injected with ML.

Kinetic stability of Fe-based nanoparticles with rheological modification by xanthan gum: A critical stabilization concentration and the underlying mechanism.

Enhanced kinetic stability of Fe-NPs in groundwater is a focus in application of Fe-NPs for groundwater remediation. The effect of surfactants (Triton X-100 and SDBS) and polymers (XG, SA, CCS, PSS and PVP) on the kinetic stability of Fe-NPs were studied with sedimentation experiments. Polymers improved stability of nFeO and XG had the best effect, while surfactants had minimal effect.

Cotransport of fullerene nanoparticles and montmorillonite colloids in porous media: Critical role of divalent cations of montmorillonite.

While the cotransport of carbon nanoparticles (CNPs) and clay colloids in porous media has been widely studied, the influence of the cation exchange capacity (CEC) of clay colloids on the transport process remains unclear. In this study, batch adsorption and column transport experiments were conducted to investigate the fate and transport of CNPs and clay colloids in quartz sand, with respect to the effect of monovalent-cation exchange capacity (mono-CEC), divalent-cation exchange capacity (di-CEC) and total CEC of clays. Fullerene nanoparticles (nC) and six types of montmorillonite (ML) with different CEC were selected as modeled CNPs and clay colloids, respectively.

Rheological behavior of xanthan gum suspensions with Fe-based nanoparticles: the effect of nanoparticles and the mechanism.

The rheological behavior of a xanthan gum (XG) suspension with Fe-based nanoparticles (Fe-NPs), , nanoparticles of zerovalent iron (nZVI) and FeO (nFeO), needs to be understood for better injection of Fe-NPs for groundwater remediation. In this study, the rheological behavior of a XG suspension of nZVI and nFeO was investigated at different particle concentrations. The Ostwald, Sisko, Williamson, and Cross models were employed to fit the rheological behavior of the suspensions for quantitatively describing the effect of the particles.

Migration and transformation of Sb are affected by Mn(III/IV) associated with lepidocrocite originating from Fe(II) oxidation.

Antimony (Sb) is a recognized priority pollutant with toxicity that is influenced by its migration and transformation processes. Oxidation of Fe(II) to Fe(III) oxides, which is a common phenomenon in the environment, is often accompanied by the formation of Mn(III/IV) and might affect the fate of Sb. In this study, incorporated Mn(III) and sorbed/precipitated Mn(III/IV) associated with lepidocrocite were prepared by adding Mn(II) during and after Fe(II) oxidation, respectively, and the effects of these Mn species on Sb fate were investigated.