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Adsorption and desorption characteristics of arsenic onto ceria nanoparticles.

Feng Q, Zhang Z, Ma Y, He X, Zhao Y, Chai Z - Nanoscale Res Lett (2012)

Bottom Line: The rapid increase in the use of engineered nanoparticles [ENPs] has resulted in an increasing concern over the potential impacts of ENPs on the environmental and human health.The desorption data showed that desorption hysteresis occurred at the initial concentration studied.High adsorption capacity of arsenic on ceria NPs suggests that the synergistic effects of ceria NPs and arsenic on the environmental systems may exist when they are released into the environment.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Nuclear Analytical Techniques and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China. zhangzhy@ihep.ac.cn.

ABSTRACT
The rapid increase in the use of engineered nanoparticles [ENPs] has resulted in an increasing concern over the potential impacts of ENPs on the environmental and human health. ENPs tend to adsorb a large variety of toxic chemicals when they are emitted into the environment, which may enhance the toxicity of ENPs and/or adsorbed chemicals. The study was aimed to investigate the adsorption and desorption behaviors of arsenic on ceria NPs in aqueous solution using batch technique. Results show that the adsorption behavior of arsenic on ceria NPs was strongly dependent on pH and independent of ionic strength, indicating that the electrostatic effect on the adsorption of these elements was relatively not important compared to surface chemical reactions. The adsorption isotherms fitted very well to both the Langmuir and Freundlich models. The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) for the adsorption of arsenic were determined at three different temperatures of 283, 303, and 323 K. The adsorption reaction was endothermic, and the process of adsorption was favored at high temperature. The desorption data showed that desorption hysteresis occurred at the initial concentration studied. High adsorption capacity of arsenic on ceria NPs suggests that the synergistic effects of ceria NPs and arsenic on the environmental systems may exist when they are released into the environment.

No MeSH data available.


Related in: MedlinePlus

Effect of ion strength on the adsorption of As(III) and As(V) on ceria NPs. Cinitial arsenic = 80 μg L-1, T = 298 K.
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Figure 4: Effect of ion strength on the adsorption of As(III) and As(V) on ceria NPs. Cinitial arsenic = 80 μg L-1, T = 298 K.

Mentions: The effects of ionic strength on the adsorption of arsenic(III) and arsenic(V) onto the surfaces of ceria NPs were presented in Figure 4. The amount of arsenic(III) and arsenic(V) adsorbed by ceria NPs was stable with increasing ionic strength from 1 × 10-8 to 1.0 mol L-1 NaNO3. Therefore, ionic strength generally had very minor or no impact on the adsorption in this study. Similar results were also observed by other reports when iron oxide or other sorbents were used [31-35].


Adsorption and desorption characteristics of arsenic onto ceria nanoparticles.

Feng Q, Zhang Z, Ma Y, He X, Zhao Y, Chai Z - Nanoscale Res Lett (2012)

Effect of ion strength on the adsorption of As(III) and As(V) on ceria NPs. Cinitial arsenic = 80 μg L-1, T = 298 K.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3293737&req=5

Figure 4: Effect of ion strength on the adsorption of As(III) and As(V) on ceria NPs. Cinitial arsenic = 80 μg L-1, T = 298 K.
Mentions: The effects of ionic strength on the adsorption of arsenic(III) and arsenic(V) onto the surfaces of ceria NPs were presented in Figure 4. The amount of arsenic(III) and arsenic(V) adsorbed by ceria NPs was stable with increasing ionic strength from 1 × 10-8 to 1.0 mol L-1 NaNO3. Therefore, ionic strength generally had very minor or no impact on the adsorption in this study. Similar results were also observed by other reports when iron oxide or other sorbents were used [31-35].

Bottom Line: The rapid increase in the use of engineered nanoparticles [ENPs] has resulted in an increasing concern over the potential impacts of ENPs on the environmental and human health.The desorption data showed that desorption hysteresis occurred at the initial concentration studied.High adsorption capacity of arsenic on ceria NPs suggests that the synergistic effects of ceria NPs and arsenic on the environmental systems may exist when they are released into the environment.

View Article: PubMed Central - HTML - PubMed

Affiliation: Key Laboratory of Nuclear Analytical Techniques and Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety, Institute of High Energy Physics, Chinese Academy of Sciences, Beijing, 100049, China. zhangzhy@ihep.ac.cn.

ABSTRACT
The rapid increase in the use of engineered nanoparticles [ENPs] has resulted in an increasing concern over the potential impacts of ENPs on the environmental and human health. ENPs tend to adsorb a large variety of toxic chemicals when they are emitted into the environment, which may enhance the toxicity of ENPs and/or adsorbed chemicals. The study was aimed to investigate the adsorption and desorption behaviors of arsenic on ceria NPs in aqueous solution using batch technique. Results show that the adsorption behavior of arsenic on ceria NPs was strongly dependent on pH and independent of ionic strength, indicating that the electrostatic effect on the adsorption of these elements was relatively not important compared to surface chemical reactions. The adsorption isotherms fitted very well to both the Langmuir and Freundlich models. The thermodynamic parameters (ΔH0, ΔS0, and ΔG0) for the adsorption of arsenic were determined at three different temperatures of 283, 303, and 323 K. The adsorption reaction was endothermic, and the process of adsorption was favored at high temperature. The desorption data showed that desorption hysteresis occurred at the initial concentration studied. High adsorption capacity of arsenic on ceria NPs suggests that the synergistic effects of ceria NPs and arsenic on the environmental systems may exist when they are released into the environment.

No MeSH data available.


Related in: MedlinePlus