In recent years, SiO2 nanoparticles (NPs) have been extensively investigated for their potential in a wide range of environmental applications, including contaminant adsorption, environmental catalysis or as carriers for encapsulated pesticides. In this study, a combination of experimental methods, including transmission electron microscopy (TEM), scanning electron microscopy (SEM), dynamic light scattering (DLS) and disc centrifuge was used to characterize two sets of hollow and solid silica NPs. NPs transport in sand-packed columns was then studied at various electrolyte concentrations to assess their mobility in typical geochemical conditions. Due to the similarities in their physical properties, solid SiO2 NPs were used as templates for mesoporous silica particles, that represent the real competitor to hollow spheres for applications as carriers or adsorbents.