Deposition and release kinetics of nano-TiO2 in saturated porous media: Effects of solution ionic strength and surfactants

作者：Godinez Itzel G; Darnault Christophe J G^*; Khodadoust Amid P; Bogdan Dorin

来源：Environmental Pollution, 2013, 174: 106-113.

DOI：10.1016/j.envpol.2012.11.002

• Titanium dioxide
• Nanoparticle
• Ionic strength
• Surfactant
• Transport
• Deposition
• Release
• Saturated porous media

The aggregation, transport and deposition kinetics (i.e. attachment and release) of TiO2 nanoparticles (nano-TiO2) 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-TiO2 thus influencing the transport and retention of the nanoaggregates in the saturated porous medium. With increasing ionic strength, the interaction between approaching nano-TiO2 and nano-TiO2 already deposited onto collectors surfaces seemed to be more favorable than the interaction between approaching nano-TiO2 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-TiO2 suggesting attachment of nano-TiO2 through secondary energy minimum.

• 出版日期2013-3