Aggregation and deposition kinetics of carboxymethyl cellulose-modified zero-valent iron nanoparticles in porous media

Highly concentrated, reactive and stable dispersion of zero-valent iron nanoparticles: Direct surface modification and site application

“…It is caused by different modes of polymer interaction with the nanoparticle surface [39]. Therefore, even relatively high polymer concentrations (i.e., tens of g L À1 ) need not be ultimately able to stabilize the nZVI particles against aggregation [22,25,40,41]. Moreover, the reactivity of the polymer modified material can be up to 24times decreased by a polymer coating [26].…”

Numerical prediction of diffusion and electric field-induced iron nanoparticle transport

“…With the development of advanced nanotechnologies since late nineties, due to their size and reactivity that allowed an easy injection,zero valent iron nanoparticles (nZVI) were considered a promising step forward in soil and groundwater clean-up, particularly targeting organochlorines [4][5][6][7][8]. The nZVI transport in porous media was studied in column tests with sand [9][10][11][12][13][14][15][16], glass beads [17][18][19] and model soils [20,21]. These studies showed that nZVI has a tendency to aggregate quickly and settle in the pores, primarily due to magnetic attractive forces [22].…”

The effects of viscosity of carboxymethyl cellulose on aggregation and transport of nanoscale zerovalent iron

“…The measurements of the mean diameters of different CMC-NZVI aggregates by DLS, NTA and microscopy were conducted after the samples were mixed for 24 min in an end-over-end rotator to ensure the uniformity of the suspension, and represent steady-state aggregate sizes. Unlike the size measurement protocols used in previous studies, sonication was not used before size measurements as the objective of the size measurements was to characterize the aggregate sizes of NZVI particles in suspension rather than the primary particle sizes (Fatisson et al, 2010, He et al, 2009, Kim et al, 2009, Phenrat et al, 2008, Raychoudhury et al, 2012, Sakulchaicharoen et al, 2010.…”

“…Furthermore, remediation of typical sites via injection of NZVI is expected to require g/L concentrations of NZVI, and at such elevated concentrations there will be extensive aggregation due to the increased likelihood of particleparticle collisions (Raychoudhury et al, 2012). Aggregates of several microns in size may be formed from NZVI, and these aggregates are likely to get filtered out during subsurface transport, and remain close to the point of injection (Phenrat et al, 2009a).…”