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Individual and Co Transport Study of Titanium Dioxide NPs and Zinc Oxide NPs in Porous Media.

Kumari J, Mathur A, Rajeshwari A, Venkatesan A, S S, Pulimi M, Chandrasekaran N, Nagarajan R, Mukherjee A - PLoS ONE (2015)

Bottom Line: 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).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.

View Article: PubMed Central - PubMed

Affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.

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.

No MeSH data available.


Related in: MedlinePlus

Retention profile of ZnO NPs at pH 9 (with and without TiO2 NPs).Retention graph of ZnO NPs in presence and absence of TiO2 NPs sand. In suspensions at 0.1, 1, and 10 mM ionic strengths in NaCl solutions and 0.01, 0.05, and 0.1 mM CaCl2 solutions at pH 9. Replicate experiments were performed under all conditions (n ≥ 2). In presence of TiO2 NPs in suspension of ZnO NPs showed decrease in retention of ZnO NPs in porous media.
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pone.0134796.g012: Retention profile of ZnO NPs at pH 9 (with and without TiO2 NPs).Retention graph of ZnO NPs in presence and absence of TiO2 NPs sand. In suspensions at 0.1, 1, and 10 mM ionic strengths in NaCl solutions and 0.01, 0.05, and 0.1 mM CaCl2 solutions at pH 9. Replicate experiments were performed under all conditions (n ≥ 2). In presence of TiO2 NPs in suspension of ZnO NPs showed decrease in retention of ZnO NPs in porous media.

Mentions: The retention profiles of ZnO NPs in presence and absence of TiO2 NPs were evaluated under three different pH conditions, 5, 7, and 9, and a series of ionic strengths [NaCl (0.1, 1, and 10 mM) and CaCl2 (0.01, 0.05, and 0.1 mM)]. At pH 5, the BTC curves of ZnO NPs were very low due to the opposite charge present between sand and ZnO NPs. So, the retention profile of ZnO NPs in absence of TiO2 NPs was very high as shown in Figs 10, 11 and 12. The retention profile of ZnO NPs in the presence of TiO2 NPs was higher in sand.


Individual and Co Transport Study of Titanium Dioxide NPs and Zinc Oxide NPs in Porous Media.

Kumari J, Mathur A, Rajeshwari A, Venkatesan A, S S, Pulimi M, Chandrasekaran N, Nagarajan R, Mukherjee A - PLoS ONE (2015)

Retention profile of ZnO NPs at pH 9 (with and without TiO2 NPs).Retention graph of ZnO NPs in presence and absence of TiO2 NPs sand. In suspensions at 0.1, 1, and 10 mM ionic strengths in NaCl solutions and 0.01, 0.05, and 0.1 mM CaCl2 solutions at pH 9. Replicate experiments were performed under all conditions (n ≥ 2). In presence of TiO2 NPs in suspension of ZnO NPs showed decrease in retention of ZnO NPs in porous media.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4529095&req=5

pone.0134796.g012: Retention profile of ZnO NPs at pH 9 (with and without TiO2 NPs).Retention graph of ZnO NPs in presence and absence of TiO2 NPs sand. In suspensions at 0.1, 1, and 10 mM ionic strengths in NaCl solutions and 0.01, 0.05, and 0.1 mM CaCl2 solutions at pH 9. Replicate experiments were performed under all conditions (n ≥ 2). In presence of TiO2 NPs in suspension of ZnO NPs showed decrease in retention of ZnO NPs in porous media.
Mentions: The retention profiles of ZnO NPs in presence and absence of TiO2 NPs were evaluated under three different pH conditions, 5, 7, and 9, and a series of ionic strengths [NaCl (0.1, 1, and 10 mM) and CaCl2 (0.01, 0.05, and 0.1 mM)]. At pH 5, the BTC curves of ZnO NPs were very low due to the opposite charge present between sand and ZnO NPs. So, the retention profile of ZnO NPs in absence of TiO2 NPs was very high as shown in Figs 10, 11 and 12. The retention profile of ZnO NPs in the presence of TiO2 NPs was higher in sand.

Bottom Line: 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).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.

View Article: PubMed Central - PubMed

Affiliation: Centre for Nanobiotechnology, VIT University, Vellore, Tamil Nadu, India.

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.

No MeSH data available.


Related in: MedlinePlus