title: Facilitated transport of anatase titanium dioxides nanoparticles in the presence of phosphate in saturated sands.
abstract: Soil and water environments are inevitably contaminated by the excess of artificial nanoparticles (NPs) and phosphorus (P) fertilizers. There is a possibility of phosphate facilitating or inhibiting the transport of nanoparticles titanium dioxides (nTiO2). It is a great urgency and high priority to investigate the nTiO2 retention mechanisms and accurately describe the transport of nTiO2 in the presence of phosphate. Anatase nTiO2 with two sizes of 20 and 50nm through the saturated porous sand columns were observed under the conditions (0-50mM NaNO3 electrolyte, influent P concentrations of 0.10mM and 2.0mM, pH 6.5 and 7.5). The experimental results show the phosphate favor the dispersion of nTiO2, and consequently improve their transport patterns. The likely mechanism is that phosphate adsorption increasing the negative charge on the surface promotes the transportability of nTiO2 resulting from the low deposition rate and attachment efficiency of NPs. In particular, the facilitated transport of nTiO2 (50nm) is greater than those relative smaller as 20nm. In addition, this enhancement of nTiO2 transportability by phosphate at pH 6.5 is increased at higher pH of 7.5 due to the more negative zeta potential of surface, which indicates the potential risks to groundwater systems.
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Chen
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, China. Electronic address: nanxu@mail.usts.edu.cn.
authors.forename: Nan
authors.initials: N
authors.lastname: Xu
authors.affiliation: School of Environmental Science & Engineering, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Xinde
authors.initials: X
authors.lastname: Cao
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Kairong
authors.initials: K
authors.lastname: Zhou
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Yunlong
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Jiangsu Key Laboratory of Environmental Functional Materials, School of Chemistry Biology and Material Engineering, Suzhou University of Science and Technology, Suzhou 215009, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Liu
keywords: Ionic concentration; Nanoparticle titanium dioxide (nTiO(2)); Particle size; Phosphorus; Transport; pH