Influence of Ionic Strength, pH, and Cation Valence on Aggregation Kinetics of Titanium Dioxide Nanoparticles

To investigate the possibility of removing titanium dioxide nanoparticles (TiO2 NPs) from water by coagulation, as well as to find the optimal coagulant and experimental conditions for TiO2 NP removal, four types of coagulant were adopted: polyferric sulfate (PFS), ferric chloride (FeCl3), polyaluminum chloride (PACl), and alum (Al2(SO4)3). It was found that the removal of TiO2 NPs by coagulation was affected by ionic strength, alkalinity, as well as types and dosages of coagulants. PFS and FeCl3 achieved much higher removal efficiency of TiO2 NPs than PACl and Al2(SO4)3 did. For 30 mg/L TiO2 NPs, a dosage of 0.3 mM PFS (as Fe) achieved 84% removal after coagulation followed by 30 min settlement. Optimal ionic strength (0.1 M NaCl or 0.03 M CaCl2) is of vital importance for the performance of PFS. Na2SO4 is unfavorable for the performance of PFS. Optimal alkalinity (0.01–0.03 M NaHCO3) is necessary for FeCl3 to remove TiO2 NPs. Natural organic matter, as represented by humic acid (HA) up to 11 mg/L, reduces the removal of TiO2 NPs by coagulation. These findings indicate that coagulation is a good option for the removal of TiO2 NPs from water, and more attention should be paid to the effects of water quality when using coagulation to remove TiO2 NPs from aqueous matrices. This provides a possible solution to alleviate the potential hazard caused by TiO2 NPs.

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Effect of anatase–brookite mixed phase titanium dioxide nanoparticles on the high temperature decomposition kinetics of ammonium perchlorate

Materials Chemistry and Physics ◽

10.1016/j.matchemphys.2013.01.054 ◽

2013 ◽

Vol 139 (2-3) ◽

pp. 537-542 ◽

Cited By ~ 16

Author(s):

Anuj A. Vargeese ◽

Krishnamurthi Muralidharan

Keyword(s):

Titanium Dioxide ◽

High Temperature ◽

Ammonium Perchlorate ◽

Titanium Dioxide Nanoparticles ◽

Decomposition Kinetics ◽

Mixed Phase ◽

Temperature Decomposition ◽

Kinetics Of

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Dose-dependent clearance kinetics of intratracheally administered titanium dioxide nanoparticles in rat lung

Toxicology ◽

10.1016/j.tox.2014.08.003 ◽

2014 ◽

Vol 325 ◽

pp. 1-11 ◽

Cited By ~ 14

Author(s):

Naohide Shinohara ◽

Yutaka Oshima ◽

Toshio Kobayashi ◽

Nobuya Imatanaka ◽

Makoto Nakai ◽

...

Keyword(s):

Titanium Dioxide ◽

Titanium Dioxide Nanoparticles ◽

Rat Lung ◽

Clearance Kinetics ◽

Kinetics Of ◽

Dose Dependent

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High Ionic Strength Enhances the Anti-Pepsin Activity of Titanium Dioxide Nanoparticles

Nano Biomedicine and Engineering ◽

10.5101/nbe.v8i3.p136-143 ◽

2016 ◽

Vol 8 (3) ◽

Cited By ~ 1

Author(s):

Hussein Kadhem Al-Hakeim ◽

Khlowd Mohammed Jasem

Keyword(s):

Titanium Dioxide ◽

Ionic Strength ◽

Titanium Dioxide Nanoparticles ◽

High Ionic Strength ◽

Pepsin Activity

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Interaction of titanium dioxide nanoparticles with kaolinite clay particles in the presence of quartz sand

10.5194/egusphere-egu2020-20815 ◽

2020 ◽

Author(s):

Constantinos V. Chrysikopoulos ◽

Dimitra Fasouletou

Keyword(s):

Titanium Dioxide ◽

Ionic Strength ◽

Titanium Dioxide Nanoparticles ◽

Rapid Development ◽

Consumer Products ◽

Engineered Nanoparticles ◽

Kaolinite Clay ◽

Clay Particles ◽

Water Saturated ◽

Experimental And Theoretical Studies

Titanium dioxide (TiO2) is one of the most frequently employed nanoparticles (NPs) in consumer products. The rapid development of nanotechnology has led to the inevitable introduction of NPs in the natural environment, which subsequently may reach underground formations. Also, kaolinite is one of the most common minerals, which can be found in the subsurface. Numerous experimental and theoretical studies have shown that kaolinite clay particles can impact on the transport behavior of colloids, biocolloids (bacteria, viruses) and engineered nanoparticles. Therefore, the aim of this study is to examine the interaction of kaolinite (KGa-1b) particles with suspended TiO2&#160;NPs in the presence of quartz sand.Static and dynamic batch experiments were performed with three different TiO2 concentrations (50, 100, 200 mg/L) and four different ionic strength values &#8203;&#8203;(1, 25, 50, 100 mM). All of the experiments were conducted at room temperature (22 &#176;C) and pH=7.The experimental results clearly suggested that TiO2&#160;attachment onto KGa-1b particles was slightly enhanced with increasing TiO2 concentrations,but significantly increased with increasing ionic strength. Consequently, the presence of suspended KGa-1b particles can retard the TiO2 transport in water saturated porous media.

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