Removal of trichloroethylene by activated carbon in the presence and absence of Ti[O.sub.2] nanoparticles

• Published in: Water, air, and soil pollution air, and soil pollution, 2012-06, Vol.223 (5), p.2837
• Main Authors: Salih, Hafiz H, Sorial, George A, Patterson, Craig L, Sinha, Rajib, Krishnan, E. Radha
• Format: Article
• Language: English
• Subjects: Adsorption; Analysis; Nanoparticles; Titanium dioxide; Wastewater
• ISSN: 0049-6979
• DOI: 10.1007/s11270-011-1070-8

Nanoparticles (NPs) are emerging as a new type of contaminant in water and wastewater. The fate of titanium dioxide nanoparticles (Ti[O.sub.2]NPs) in a granular activated carbon (GAC) adsorber and their impact on the removal of trichloroethylene (TCE) was investigated. Key parameters governing the Ti[O.sub.2]NP-GAC interaction such as specific surface area (SSA), zeta potential, and the Ti[O.sub.2]NP particle size distribution (PSD) were determined. The impact of Ti[O.sub.2]NPs on TCE adsorption on GAC was tested by conducting TCE adsorption isotherm, kinetic, and column breakthrough studies in the presence and absence of Ti[O.sub.2]NPs. SSA and pore size distribution of the virgin and spent GAC were obtained. The fate and transport of the Ti[O.sub.2]NPs in the GAC fixed bed and their impact on TCE adsorption were found to be a function of their zeta potential, concentration, PSD, and the nature of their aggregation. The Ti[O.sub.2]NPs under investigation are not stable in water and rapidly form larger aggregates. Due to the fast adsorption kinetics of TCE, the isotherm and kinetic studies found no effect from Ti[O.sub.2]NPs. However, Ti[O.sub.2]NPs attached to GAC and led to a reduction in the amount of TCE adsorbed during the breakthrough experiments suggesting a preloading pore blockage phenomenon. The analysis of the used GAC confirmed the pore blockage and SSA reduction. Keywords Activated carbon * Adsorption * Nanoparticles * Trichloroethylene