Effects of water quality parameters on agglomeration and dissolution of copper oxide nanoparticles (CuO-NPs) using a central composite circumscribed design

Son, Jino; Vavra, Janna M.; Forbes, Valery E.

doi:10.1016/j.scitotenv.2015.03.093

Cited by 48 publications

(31 citation statements)

References 30 publications

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“…The pH-dependent dissolution was also observed for the samples in the dark, although the dissolution extent was much lower than that of samples in the light, with rapid dissolution equilibrium within 4 h. Clearly, these findings show that acidic conditions can accelerate the Ag 2 S-NP dissolution, exhibiting a tendency similar to copper oxide (CuO) and zinc oxide (ZnO) NPs. 27,28 Past studies have shown that transformation of metal-based NPs was highly pH-dependent; lower pH, in general, would remarkably enhance metal-based NP dissolution, 29,30 which is well-consistent with our finding in this study. On the other hand, we found that dissolved silver began to decline at different times among the tested Ag 2 S-NP solutions with varied pH (Figure 2b).…”

Section: ■ Results and Discussionsupporting

confidence: 91%

Rethinking Stability of Silver Sulfide Nanoparticles (Ag₂S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag₂S-NPs in the Presence of Fe(III)

Wang

Liu

et al. 2015

Environ. Sci. Technol.

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ABSTRACT:The stability of engineered nanomaterials in a natural aquatic environment has drawn much attention over the past few years. Silver sulfide nanoparticles (Ag 2 S-NPs) are generally assumed to be stable in a natural environment as a result of their physicochemical property; however, it may vary depending upon environmental conditions. Here, we investigated whether and how the environmentally relevant factors including light irradiation, solution pH, inorganic salts, dissolved organic matter (DOM), and dissolved oxygen (DO) individually and in combination influenced the stability of Ag 2 S-NPs in an aquatic environment. We presented for the first time that transformation of Ag 2 S-NPs can indeed occur in the aqueous system with an environmentally relevant concentration of Fe 3+ under simulated solar irradiation and natural sunlight within a short time (96 h), along with significant changes in morphology and dissolution. The photoinduced transformation of Ag 2 S-NPs in the presence of Fe 3+ can be dramatically influenced by solution pH, Ca 2+ /Na + , Cl − /SO 4 2− , DOM, and DO. Moreover, Ag 2 S-NP dissolution increased within 28 h, followed rapid decline in the next 68 h, which may be a result of the reconstitution of small Ag 2 S-NPs. Taken together, this work is of importance to comprehensively evaluate the stability of Ag 2 S-NPs in an aquatic environment, improving our understanding of their potential risks to human and environmental health.

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Section: ■ Results and Discussionsupporting

confidence: 91%

Rethinking Stability of Silver Sulfide Nanoparticles (Ag₂S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag₂S-NPs in the Presence of Fe(III)

Wang

Liu

et al. 2015

Environ. Sci. Technol.

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“…1a). Because NPs tend to aggregate when their surface charge is close to zero, the more significant influence of divalent counter-ions on CuO NP aggregation than the monovalent counter-ions was suggested through the changes of zeta potential (Son et al 2015;Sousa and Teixeira 2013). The aggregation attachment efficiency (α) analysis of CuO NPs in the NaNO 3 and Ca(NO 3 ) 2 solutions clearly depicted a reaction-limited (slow) and diffusion-limited (fast) aggregation regime (Fig.…”

Section: Cuo Np Aggregation Kinetics With Monovalent and Divalent Catmentioning

confidence: 97%

“…It has been demonstrated that the solution pH can influence the surface charge through a pH-dependent protonation and deprotonation of surface hydroxyl groups (Philippe and Schaumann 2014), which affects the aggregation and transport of NPs. Effects of various electrolytes were also investigated, and divalent ions can promote agglomeration of NPs due to compression of the electrical double layer (Son et al 2015). Typically, higher NOM concentrations result in enhanced NP stability (Adeleye et al 2014;Grillo et al 2015): more adsorbed mass of NOM on the NPs induces electrostatic repulsion (attributable to negatively charged carboxylate groups) and electrosteric repulsion for high molecular weight components (Philippe and Schaumann 2014;Zhang et al 2009).…”

Section: Responsible Editor: Thomas D Buchelimentioning

confidence: 99%

Effect of alginate on the aggregation kinetics of copper oxide nanoparticles (CuO NPs): bridging interaction and hetero-aggregation induced by Ca2+

Miao

Wang

Hou

et al. 2016

Environ Sci Pollut Res

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The stability of CuO nanoparticles (NPs) is expected to play a key role in the environmental risk assessment of nanotoxicity in aquatic systems. In this study, the effect of alginate (model polysaccharides) on the stability of CuO NPs in various environmentally relevant ionic strength conditions was investigated by using time-resolved dynamic light scattering. Significant aggregation of CuO NPs was observed in the presence of both monovalent and divalent cations. The critical coagulation concentrations (CCC) were 54.5 and 2.9 mM for NaNO3 and Ca(NO3)2, respectively. The presence of alginate slowed nano-CuO aggregation rates over the entire NaNO3 concentration range due to the combined electrostatic and steric effect. High concentrations of Ca(2+) (>6 mM) resulted in stronger adsorption of alginate onto CuO NPs; however, enhanced aggregation of CuO NPs occurred simultaneously under the same conditions. Spectroscopic analysis revealed that the bridging interaction of alginate with Ca(2+) might be an important mechanism for the enhanced aggregation. Furthermore, significant coagulation of the alginate molecules was observed in solutions of high Ca(2+) concentrations, indicating a hetero-aggregation mechanism between the alginate-covered CuO NPs and the unabsorbed alginate. These results suggested a different aggregation mechanism of NPs might co-exist in aqueous systems enriched with natural organic matter, which should be taken into consideration in future studies. Graphical abstract Hetero-aggregation mechanism of CuO nanoparticles and alginate under high concentration of Ca(2.)

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“…It consists of three interlocking 2 2 factorial designs having points, all lying on the surface of a sphere surrounding the center of the design [32]. RSM has also been applied for the optimization of several chemical and physical processes [33,34], and the number of experiments is decided accordingly.…”

Section: Introductionmentioning

confidence: 99%

Synthesis and Characterization of Reduced Graphene Oxide-Supported Nanoscale Zero-Valent Iron (nZVI/rGO) Composites Used for Pb(II) Removal

Fan

et al. 2016

Materials

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Reduced graphene oxide-supported nanoscale zero-valent iron (nZVI/rGO) composites were prepared by chemical deposition method and were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Raman spectroscopy, N2-sorption and X-ray photoelectron spectroscopy (XPS). Operating parameters for the removal process of Pb(II) ions, such as temperature (20–40 °C), pH (3–5), initial concentration (400–600 mg/L) and contact time (20–60 min), were optimized using a quadratic model. The coefficient of determination (R2 > 0.99) obtained for the mathematical model indicates a high correlation between the experimental and predicted values. The optimal temperature, pH, initial concentration and contact time for Pb(II) ions removal in the present experiment were 21.30 °C, 5.00, 400.00 mg/L and 60.00 min, respectively. In addition, the Pb(II) removal by nZVI/rGO composites was quantitatively evaluated by using adsorption isotherms, such as Langmuir and Freundlich isotherm models, of which Langmuir isotherm gave a better correlation, and the calculated maximum adsorption capacity was 910 mg/g. The removal process of Pb(II) ions could be completed within 50 min, which was well described by the pseudo-second order kinetic model. Therefore, the nZVI/rGO composites are suitable as efficient materials for the advanced treatment of Pb(II)-containing wastewater.

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Effects of water quality parameters on agglomeration and dissolution of copper oxide nanoparticles (CuO-NPs) using a central composite circumscribed design

Cited by 48 publications

References 30 publications

Rethinking Stability of Silver Sulfide Nanoparticles (Ag₂S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag₂S-NPs in the Presence of Fe(III)

Rethinking Stability of Silver Sulfide Nanoparticles (Ag₂S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag₂S-NPs in the Presence of Fe(III)

Effect of alginate on the aggregation kinetics of copper oxide nanoparticles (CuO NPs): bridging interaction and hetero-aggregation induced by Ca2+

Synthesis and Characterization of Reduced Graphene Oxide-Supported Nanoscale Zero-Valent Iron (nZVI/rGO) Composites Used for Pb(II) Removal

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Effects of water quality parameters on agglomeration and dissolution of copper oxide nanoparticles (CuO-NPs) using a central composite circumscribed design

Cited by 48 publications

References 30 publications

Rethinking Stability of Silver Sulfide Nanoparticles (Ag2S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag2S-NPs in the Presence of Fe(III)

Rethinking Stability of Silver Sulfide Nanoparticles (Ag2S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag2S-NPs in the Presence of Fe(III)

Effect of alginate on the aggregation kinetics of copper oxide nanoparticles (CuO NPs): bridging interaction and hetero-aggregation induced by Ca2+

Synthesis and Characterization of Reduced Graphene Oxide-Supported Nanoscale Zero-Valent Iron (nZVI/rGO) Composites Used for Pb(II) Removal

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Rethinking Stability of Silver Sulfide Nanoparticles (Ag₂S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag₂S-NPs in the Presence of Fe(III)

Rethinking Stability of Silver Sulfide Nanoparticles (Ag₂S-NPs) in the Aquatic Environment: Photoinduced Transformation of Ag₂S-NPs in the Presence of Fe(III)