title: Transport and retention of engineered Al2O3, TiO2, and SiO2 nanoparticles through various sedimentary rocks.
abstract: Engineered aluminum oxide (Al2O3), titanium dioxide (TiO2), and silicon dioxide (SiO2) nanoparticles (NPs) are utilized in a broad range of applications; causing noticeable quantities of these materials to be released into the environment. Issues of how and where these particles are distributed into the subsurface aquatic environment remain as major challenges for those in environmental engineering. In this study, transport and retention of Al2O3, TiO2, and SiO2 NPs through various saturated porous media were investigated. Vertical columns were packed with quartz-sand, limestone, and dolomite grains. The NPs were introduced as a pulse suspended in aqueous solutions and breakthrough curves in the column outlet were generated using an ultraviolet-visible spectrophotometer. It was found that Al2O3 and TiO2 NPs are easily transported through limestone and dolomite porous media whereas NPs recoveries were achieved two times higher than those found in the quartz-sand. The highest and lowest SiO2-NPs recoveries were also achieved from the quartz-sand and limestone columns, respectively. The experimental results closely replicated the general trends predicted by the filtration and DLVO calculations. Overall, NPs mobility through a porous medium was found to be strongly dependent on NP surface charge, NP suspension stability against deposition, and porous medium surface charge and roughness.
authors.affiliation: UTM-MPRC Institute for Oil and Gas, N29A, Lengkuk Suria, Universiti Teknologi Malaysia, 81310, UTM Skudai, Johor Bahru, Malaysia.
authors.forename: Ali Esfandyari
authors.initials: AE
authors.lastname: Bayat
authors.affiliation: UTM-MPRC Institute for Oil and Gas, N29A, Lengkuk Suria, Universiti Teknologi Malaysia, 81310, UTM Skudai, Johor Bahru, Malaysia.
authors.forename: Radzuan
authors.initials: R
authors.lastname: Junin
authors.affiliation: Department of Computer System and Information Technology, Faculty of Computer System and Information Technology, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Shahaboddin
authors.initials: S
authors.lastname: Shamshirband
authors.affiliation: Department of Mechanical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
authors.forename: Wen Tong
authors.initials: WT
authors.lastname: Chong