title: Individual and Co Transport Study of Titanium Dioxide NPs and Zinc Oxide NPs in Porous Media.
abstract: The impact of pH and ionic strength on the mobility (individual and co-transport) and deposition kinetics of TiO2 and ZnO NPs in porous media was systematically investigated in this study. Packed column experiments were performed over a series of environmentally relevant ionic strengths with both NaCl (0.1-10 mM) and CaCl2 (0.01-0.1mM) solutions and at pH 5, 7, and 9. The transport of TiO2 NPs at pH 5 was not significantly affected by ZnO NPs in solution. At pH 7, a decrease in TiO2 NP transport was noted with co-existence of ZnO NPs, while at pH 9 an increase in the transport was observed. At pH 5 and 7, the transport of ZnO NPs was decreased when TiO2 NPs was present in the solution, and at pH 9, an increase was noted. The breakthrough curves (BTC) were noted to be sensitive to the solution chemistries; the decrease in the breakthrough plateau with increasing ionic strength was observed under all examined pH (5, 7, and 9). The retention profiles were the inverse of the plateaus of BTCs, as expected from mass balance considerations. Overall, the results from this study suggest that solution chemistries (ionic strength and pH) are likely the key factors that govern the individual and co-transport behavior of TiO2 and ZnO NPs in sand.
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Jyoti
authors.initials: J
authors.lastname: Kumari
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Ankita
authors.initials: A
authors.lastname: Mathur
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: A
authors.initials: A
authors.lastname: Rajeshwari
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Arthi
authors.initials: A
authors.lastname: Venkatesan
authors.affiliation: Department of Microbiology and Cell Biology, IISc, Bangalore, Karnataka, India.
authors.forename: Satyavati
authors.initials: S
authors.lastname: S
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Mrudula
authors.initials: M
authors.lastname: Pulimi
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Natarajan
authors.initials: N
authors.lastname: Chandrasekaran
authors.affiliation: Department of Chemical Engineering, IIT Madras, Chennai, India.
authors.forename: R
authors.initials: R
authors.lastname: Nagarajan
authors.affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.
authors.forename: Amitava
authors.initials: A
authors.lastname: Mukherjee
mesh_terms: D006863:Hydrogen-Ion Concentration; D053768:Metal Nanoparticles / Q000648:ultrastructure; D016062:Porosity; D014025:Titanium / Q000737:chemistry*; D015034:Zinc Oxide / Q000737:chemistry*
chemical_list: C009495:titanium dioxide; D014025:Titanium; D015034:Zinc Oxide