title: Deposition and release kinetics of nano-TiO2 in saturated porous media: effects of solution ionic strength and surfactants.
abstract: The aggregation, transport and deposition kinetics (i.e. attachment and release) of TiO(2) nanoparticles (nano-TiO(2)) were investigated as a function of ionic strength and the presence of anionic (sodium dodecylbenzene sulfonate, SDBS) and non-ionic (Triton X-100) surfactants in 100% critical micelle concentration (CMC). The electrolyte concentration of the suspensions dictated the kinetic stability of nano-TiO(2) thus influencing the transport and retention of the nanoaggregates in the saturated porous medium. With increasing ionic strength, the interaction between approaching nano-TiO(2) and nano-TiO(2) already deposited onto collectors surfaces seemed to be more favorable than the interaction between approaching nano-TiO(2) and bare collectors surfaces. The abrupt and gradual reduction in electrolyte concentration during the flushing cycles of the column experiments induced the release of previously deposited nano-TiO(2) suggesting attachment of nano-TiO(2) through secondary energy minimum.
authors.affiliation: Department of Civil and Materials Engineering, Hydromechanics and Water Resources Engineering Laboratory, University of Illinois at Chicago, 842 W. Taylor St., Chicago, IL 60607, USA.
authors.forename: Itzel G
authors.initials: IG
authors.lastname: Godinez
authors.forename: Christophe J G
authors.initials: CJ
authors.lastname: Darnault
authors.forename: Amid P
authors.initials: AP
authors.lastname: Khodadoust
authors.forename: Dorin
authors.initials: D
authors.lastname: Bogdan
mesh_terms: D001557:Benzenesulfonates / Q000737:chemistry; D007700:Kinetics; D053768:Metal Nanoparticles / Q000032:analysis / Q000737:chemistry*; D008956:Models, Chemical; D017830:Octoxynol / Q000737:chemistry; D009994:Osmolar Concentration; D010316:Particle Size; D016062:Porosity; D013501:Surface-Active Agents / Q000737:chemistry*; D014025:Titanium / Q000032:analysis / Q000737:chemistry*
chemical_list: D001557:Benzenesulfonates; D013501:Surface-Active Agents; C009495:titanium dioxide; C001114:dodecylbenzenesulfonic acid; D017830:Octoxynol; D014025:Titanium