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| 2. |
- Hassellöv, Martin, 1970, et al.
(författare)
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REACH missar nano!
- 2009
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Ingår i: Miljöforskning. ; 2009:3-4
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Tidskriftsartikel (övrigt vetenskapligt/konstnärligt)
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| 3. |
- Tuoriniemi, Jani, 1982, et al.
(författare)
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Size dependence of silver nanoparticle removal in a wastewater treatment plant mesocosm measured by FAST single particle ICP-MS
- 2017
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Ingår i: Environmental Science-Nano. - : Royal Society of Chemistry (RSC). - 2051-8153 .- 2051-8161. ; 4:5, s. 1189-1197
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Tidskriftsartikel (refereegranskat)abstract
- The quantities of engineered nanoparticles (NP) released to the environment are often influenced by their fate in waste water treatment plants (WWTP). Here, 40 nm silver NP (AgNP) were spiked into a mesocosm simulating the process used at a major municipal WWTP. The evolution of the mass distributions and number concentrations were followed by fast acquisition speed technique single particle inductively coupled mass spectrometry (FAST spICP-MS) using a high-resolution ICP-MS. It was thus possible to detect smaller Ag containing NP than hitherto possible in similar studies. These small particles (ca. 5-10 nm in corresponding metallic Ag equivalent spherical diameter) were possibly dissolved Ag+ precipitated as Ag2S particles. They were detected immediately upon spiking and were stable with respect to aggregation and thus much less removed by the WWTP process compared to the 40 nm AgNP. The results also suggested that any transformation of the latter AgNP occurred without dissolution. Most of these larger AgNP were probably removed by aggregation with large floc particles and subsequent sedimentation with the suspended particulate matter in the simulated WWTP process. The results have implications for differentiating the fate of nanoparticles as a function of size and demonstrate how spICP-MS can reveal such size-dependent fate dynamics.
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| 4. |
- Gallego-Urrea, Julian A., 1977, et al.
(författare)
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Multimethod 3D characterization of natural plate-like nanoparticles: shape effects on equivalent size measurements
- 2014
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Ingår i: Journal of nanoparticle research. - : Springer Science and Business Media LLC. - 1388-0764 .- 1572-896X. ; 16:5
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Tidskriftsartikel (refereegranskat)abstract
- The fundamental properties and processes that govern nanoparticle behavior in colloidal dispersions are critical to predict their performance in applications and also their environmental and health implications. Illite is a platy clay mineral that is present in large amounts in aquatic environments and can be used as a model natural particle for environmental risk assessment. However, the high-aspect ratio of illite makes conventional analysis, usually assuming a spherical size, insufficient for the assessment of shape-dependent properties. In the current paper, a multimethod characterization of a suspension of illite particles was done using atomic force microscopy, scanning electron microscopy, dynamic light scattering (DLS), nanoparticle tracking analysis, differential centrifugal sedimentation, and centrifugal- field flow fractionation coupled to multiangle light scattering and DLS. The relation between the different measurands was investigated, and the effect of the shape on the equivalent particle size was reported. While some of the used techniques are capable of assessing the aspect ratio of illite, the results confirm the need for multiple techniques and analysis of different types of measurands especially for high-aspect-ratio particles.
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| 5. |
- Gallego-Urrea, Julian A., 1977, et al.
(författare)
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Influence of different types of natural organic matter on titania nanoparticle stability: effects of counter ion concentration and pH
- 2014
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Ingår i: Environmental Science-Nano. - : Royal Society of Chemistry (RSC). - 2051-8153. ; 1:2, s. 181-189
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Tidskriftsartikel (refereegranskat)abstract
- The effects of biopolymeric (alginate) and refractory macromolecules (humic and fulvic acids) on the aggregation kinetics of anatase titanium dioxide (titania) nanoparticles were evaluated. The particles were synthesized using a wet-chemical method based on the hydrolysis of TiCl4. Stable suspensions of positively-charged titania were obtained at pH 2.5. One batch of this product was shifted above the point of zero charge to pH 12. These dispersions were mixed with three different types of well characterized environmental macromolecules: sodium alginate, fulvic acid and humic acid, and evaluated in terms of the stability. Changes in the particle size were measured using time-resolved dynamic light scattering (TR-DLS) at different concentrations of three electrolytes: NaCl, CaCl2 and Na2SO4, and at different solution pH values. Results were in agreement with DLVO calculations. The use of TR-DLS for determining aggregation rates is critically discussed.
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| 6. |
- Gallego-Urrea, Julian A., 1977, et al.
(författare)
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Coagulation and sedimentation of gold nanoparticles and illite in model natural waters: Influence of initial particle concentration
- 2016
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Ingår i: NanoImpact. - : Elsevier BV. - 2452-0748. ; 3-4
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Tidskriftsartikel (refereegranskat)abstract
- Gold nanoparticles (AuNP) possess unique characteristics that render them adequate for applications and also to be used as a model NP to evaluate the fate and behavior at low NP concentrations due to the ease of detection by modern analytical techniques. Moreover, AuNP may result in some negative effects in the environment and there is a necessity to predict their aquatic environmental concentrations by parameterizing the underlying transport and transformation processes. This study investigated the coagulation and sedimentation of 30 nm citrate-coated AuNP under enviro-mimicking conditions, i.e. model natural freshwaters (MNW) covering the range of European water chemistries relevant for colloids and NP (major ions, pH and dissolved organic matter) and artificial seawater (ASW). Firstly, the coagulation rates of AuNP at mg/L concentrations were evaluated using time-resolved dynamic light scattering which showed a decreased rate upon addition of Suwannee river natural organic matter (SRNOM) at low ionic strength (IS) but remained relatively high at high IS. Contrastingly, AuNP approaching environmental realistic concentrations (80 μg/L) in quiescent microcosms showed slow decline rates in all MNW and ASW regardless of the presence of SRNOM, as measured by nanoparticle tracking analysis and elemental Au spectrometry. When illite was added as model natural colloid the rates of decline of AuNP remained low as well. This is owing to limited collisions at low particle number concentrations. The results show that besides IS, pH, NOM concentration and type and the intrinsic surface charge of the particles, the particle number concentration and size distribution of both AuNP and natural colloids determine the extent of the large-scale fate of NP in aquatic environments.
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| 7. |
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| 8. |
- Calisi, A., et al.
(författare)
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Ecotoxicological effects of silver nanoparticles in marine mussels
- 2022
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Ingår i: Science of the Total Environment. - : Elsevier BV. - 0048-9697. ; 851
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Tidskriftsartikel (refereegranskat)abstract
- As the production of silver nanoparticles (AgNPs) is becoming more prevalent, it is becoming increasingly necessary to understand the toxicological effects they can have on different ecosystems. In the marine bioindicator species M. galloprovincialis Lam we predicted toxicity and bioaccumulation of 5 nm alkane-coated and 50 nm uncoated silver nanoparticles (AgNPs) along with silver nitrate as a function of the actual dose level. We generated a time persistence model of silver in seawater and used the Area Under the Curve (AUC) as independent variable in the hazard assessment. This approach allowed us to evaluate unbiased ecotoxicological endpoints for acute (survival) and chronic toxicity (byssal adhesion). Logistic regression analysis rendered an overall LC5096h values of 0.81 & PLUSMN; 0.07 mg h L-1 irrespectively of the silver form. By contrast, for byssal adhesion regression analysis revealed a much higher toxicological potential of silver nitrate vs AgNPs with EC5024h values respectively of 0.0024 & PLUSMN; 0.0009 vs 0.053 & PLUSMN; 0.016 and 0.063 (no computable error for 50 nm AgNP) mg h L-1, undoubtedly confirming a prevalence of ionic silver effects over AgNPs. Bioaccumulation was more efficient for silver nitrate > 5 nm AgNP > 50 nm AgNP reflecting a parallel with the prefer-ential uptake route / target organ. Finally, we derived Risk Quotient (RQs) for acute and chronic effects of nanosilver in shellfish and showed that the RQs are far from the Level of Concern (LoC) at current estimated environmental concentrations (EECs). This information can ultimately help researchers, policy makers, and industry professionals decide how to safely regulate and/or dis-pose of AgNPs.
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| 9. |
- Praetorius, A., et al.
(författare)
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Strategies for determining heteroaggregation attachment efficiencies of engineered nanoparticles in aquatic environments
- 2020
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Ingår i: Environmental Science-Nano. - : Royal Society of Chemistry (RSC). - 2051-8153 .- 2051-8161. ; 7:2, s. 351-367
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Tidskriftsartikel (refereegranskat)abstract
- Heteroaggregation of engineered nanoparticles (ENPs) with suspended particulate matter (SPM) ubiquitous in natural waters often dominates the transport behaviour and overall fate of ENPs in aquatic environments. In order to provide meaningful exposure predictions and support risk assessment for ENPs, environmental fate and transport models require quantitative information about this process, typically in the form of the so-called attachment efficiency for heteroaggregation alpha(hetero). The inherent complexity of heteroaggregation-encompassing at least two different particle populations, various aggregation pathways and several possible attachment efficiencies (alpha values)-makes its theoretical and experimental determination challenging. In this frontier review we assess the current state of knowledge on heteroaggregation of ENPs with a focus on natural surface waters. A theoretical analysis presents relevant equations, outlines the possible aggregation pathways and highlights different types of alpha. In a second part, experimental approaches to study heteroaggregation and derive alpha values are reviewed and three possible strategies are identified: i) monitoring changes in size, ii) monitoring number or mass distribution and iii) studying indirect effects, such as sedimentation. It becomes apparent that the complexity of heteroaggregation creates various challenges and no single best method for its assessment has been developed yet. Nevertheless, many promising strategies have been identified and meaningful data can be derived from carefully designed experiments when accounting for the different concurrent aggregation pathways and clearly stating the type of alpha reported. For future method development a closer connection between experiments and models is encouraged.
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| 10. |
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