Adsorption of thallium(I) on rutile nano-titanium dioxide and environmental implications

Abstract

Rutile nano-titanium dioxide (RNTD) characterized by loose particles with diameter in 20–50 nm has a very large surface area for adsorption of Tl, a typical trace metal that has severe toxicity. The increasing application of RNTD and widespread discharge of Tl-bearing effluents from various industrial activities would increase the risk of their co-exposure in aquatic environments. The adsorption behavior of Tl(I) (a prevalent form of Tl in nature) on RNTD was studied as a function of solution pH, temperature, and ion strength. Adsorption isotherms, kinetics, and thermodynamics for Tl(I) were also investigated. The adsorption of Tl(I) on RNTD started at very low pH values and increased abruptly, then maintained at high level with increasing pH >9. Uptake of Tl(I) was very fast on RNTD in the first 15 min then slowed down. The adsorption of Tl(I) on RNTD was an exothermic process; and the adsorption isotherm of Tl(I) followed the Langmuir model, with the maximum adsorption amount of 51.2 mg/g at room temperature. The kinetics of Tl adsorption can be described by a pseudo-second-order equation. FT-IR spectroscopy revealed that -OH and -TiOO-H play an important role in the adsorption. All these results indicate that RNTD has a fast adsorption rate and excellent adsorption amount for Tl(I), which can thus alter the transport, bioavailability and fate of Tl(I) in aqueous environment.

Cytotoxicity of Metal‐Based Nanoparticles: From Mechanisms and Methods of Evaluation to Pathological Manifestations

“…Considerable experimental and theoretical efforts have been directed toward understanding the cytotoxic effects and interaction mechanisms of metal-based NPs; however, the potential risks associated with metal-based NPs do not allow their routine use in clinical medicine. Metal-based NPs exhibit size, surface, and quantum properties that may lead to abnormal features in adsorption, [5] chemical reaction, [6] dispersion or agglomeration, [7,8] and tissue penetration. [9] The cytotoxicity of metal-based NPs depends on their composition, size, shape, surface charge, solubility, coating material, and reactivity.…”

Chemically Modified Nanoparticles for Enhanced Antioxidant and Antimicrobial Properties with Cinnamon Essential Oil

“…It is possible to determine that cinnamon essential oil is not causing alterations or modifications in the crystalline structure of CaCO 3 . Similarly, in Figure 2B, the diffractogram of TiO 2 reveals the crystallographic planes (110), ( 101), ( 200), ( 111), ( 210), ( 211), ( 220), ( 002), (310), (301), and (112) [24,25]. This is consistent with the results of Joni et al [26], who worked with TiO 2 nanoparticles in the rutile phase and reported positions at 2θ of 27.42 • , 36.08 • , 41.25 • , 54.33 • , and 63.44 • , corresponding to the crystallographic planes mentioned in this article.…”

Effective Thallium(I) Removal by Nanocellulose Bioadsorbent Prepared by Nitro-Oxidation of Sorghum Stalks

“…The comparison of the Q m value for Tl(I) removal by various adsorbents are listed in Table 3 . This table included inorganic adsorbents (such as multiwalled carbon nanotubes [ 22 ], polyacrylamide-aluminosilicate composites [ 22 ] and nano-titanium dioxide [ 58 ]). It was seen that NOCNF extracted from sorghum stalks possessed the highest Q m value (almost twice of those for titanate nanotube- 709.2 mg/g [ 59 ] and nanosized manganese dioxide-672.7 mg/g [ 19 ]).…”