Transport of engineered nanoparticles in saturated porous media

Tian, Yuan; Gao, Bin; Silvera-Batista, Carlos A.; Ziegler, Kirk J.

doi:10.1007/s11051-010-9912-7

Cited by 180 publications

(109 citation statements)

References 48 publications

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“…It was also found that the aggregation process of the alginate-coated hematite nanoparticles is consistent with the classical DLVO theory [160]. Some other studies have also indicated that DLVO theory can be used to describe the platelet interactions in montmorillonite systems [161,162].…”

Section: Dlvosupporting

confidence: 65%

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Wang

Adeleye

Huang

et al. 2015

Advances in Colloid and Interface Science

170

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The application of nanoparticles has raised concern over the safety of these materials to human health and the ecosystem. After release into an aquatic environment, nanoparticles are likely to experience heteroaggregation with biocolloids, geocolloids, natural organic matter (NOM) and other types of nanoparticles. Heteroaggregation is of vital importance for determining the fate and transport of nanoparticles in aqueous phase and sediments. In this article, we review the typical cases of heteroaggregation between nanoparticles and biocolloids and/or geocolloids, mechanisms, modeling, and important indicators used to determine heteroaggregation in aqueous phase. The major mechanisms of heteroaggregation include electric force, bridging, hydrogen bonding, and chemical bonding. The modeling of heteroaggregation typically considers DLVO, X-DLVO, and fractal dimension. The major indicators for studying heteroaggregation of nanoparticles include surface charge measurements, size measurements, observation of morphology of particles and aggregates, and heteroaggregation rate determination. In the end, we summarize the research challenges and perspective for the heteroaggregation of nanoparticles, such as the determination of α hetero values and heteroaggregation rates; more accurate analytical methods instead of DLS for heteroaggregation measurements; sensitive analytical techniques to measure low concentrations of nanoparticles in heteroaggregation systems; appropriate characterization of NOM at the molecular level to understand the structures and fractionation of NOM; effects of different types, concentrations, and fractions of NOM on the heteroaggregation of nanoparticles; the quantitative adsorption and desorption of NOM onto the surface of nanoparticles and heteroaggregates; and a better understanding of the fundamental mechanisms and modeling of heteroaggregation in natural water which is a complex system containing NOM, nanoparticles, biocolloids and geocolloids.

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Section: Dlvosupporting

confidence: 65%

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Wang

Adeleye

Huang

et al. 2015

Advances in Colloid and Interface Science

170

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“…SWCNTs are expected to experience some mobility in low IS soils (1.7 m), but transport could also be as low as 5-20 cm (Jaisi and Elimelech 2009;Jaisi et al 2008). CNTs, MWCNTs, and Ag are expected to be relatively mobile, approximately to the same extent as natural clay colloids (Mattison et al 2011;Tian et al 2010). Al 2 O 3 and uncoated nZVI, on the other hand, are expected to experience very little transport (Darlington et al 2009;Jaisi and Elimelech 2009;Schrick et al 2004).…”

Section: Transformationsmentioning

confidence: 99%

Emerging patterns for engineered nanomaterials in the environment: a review of fate and toxicity studies

2014

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A comprehensive assessment of the environmental risks posed by engineered nanomaterials (ENMs) entering the environment is necessary, due in part to the recent predictions of ENM release quantities and because ENMs have been identified in waste leachate. The technical complexity of measuring ENM fate and transport processes in all environments necessitates identifying trends in ENM processes. Emerging information on the environmental fate and toxicity of many ENMs was collected to provide a better understanding of their environmental implications. Little research has been conducted on the fate of ENMs in the atmosphere; however, most studies indicate that ENMs will in general have limited transport in the atmosphere due to rapid settling. Studies of ENM fate in realistic aquatic media indicates that in general, ENMs are more stable in freshwater and stormwater than in seawater or groundwater, suggesting that transport may be higher in freshwater than in seawater. ENMs in saline waters generally sediment out over the course of hours to days, leading to likely accumulation in sediments. Dissolution is significant for specific ENMs (e.g., Ag, ZnO, copper ENMs, nano zero-valent iron), which can result in their transformation from nanoparticles to ions, but the metal ions pose their own toxicity concerns. In soil, the fate of ENMs is strongly dependent on the size of the ENM aggregates, groundwater chemistry, as well as the pore size and soil particle size. Most groundwater studies have focused on unfavorable deposition conditions, but that is unlikely to be the case in many natural groundwaters with significant ionic strength due to hardness or salinity. While much still needs to be better understood, emerging patterns with regards to ENM fate, transport, and exposure combined with emerging information on toxicity indicate that risk is low for most ENMs, though current exposure estimates compared with current data on toxicity indicates that at current production and release levels, exposure to Ag, nZVI, and ZnO may cause toxicity to freshwater and marine species.

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“…Nanoparticle sizes were generally larger in the presence of natural colloids, resulting from the interaction of multiple particle types, which could potentially lead to their sedimentation in receptor environments. [15,16,18,41] Nonetheless, as shown above, the particle coatings of these novel materials played a key role in determining their physicochemical stability. [1,5,7,8] For the PAA coating, nAg remained extremely stable in the water column, even in the presence of substantial agglomeration of the surrounding colloidal particles.…”

Section: Discussionmentioning

confidence: 97%

“…homoagglomeration). [14][15][16][17][18] Indeed, it was suggested recently that the heteroagglomeration of nAg was responsible for a decrease in its microbial activity. [19] Therefore, the goal of the present study was to evaluate the importance of heteroagglomeration in natural systems by focussing on low nanoparticle to colloid ratios (1 : 200) and nanoparticle concentrations that may be found in natural waters.…”

Section: Introductionmentioning

confidence: 99%

Heteroagglomeration of nanosilver with colloidal SiO2 and clay

et al. 2017

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Environmental context. The fate of nanomaterials in the environment is related to their colloidal stability. Although numerous studies have examined their homoagglomeration, their low concentration and the presence of high concentrations of natural particles implies that heteroagglomeration rather than homoagglomeration is likely to occur under natural conditions. In this paper, two state-of-the art analytical techniques were used to identify the conditions under which nanosilver was most likely to form heteroagglomerates in natural waters.Abstract. The environmental risk of nanomaterials will depend on their persistence, mobility, toxicity and bioaccumulation. Each of these parameters is related to their fate (especially dissolution, agglomeration). The goal of this paper was to understand the heteroagglomeration of silver nanoparticles in natural waters. Two small silver nanoparticles (nAg, ,3 nm; polyacrylic acid-and citrate-stabilised) were covalently labelled with a fluorescent dye and then mixed with colloidal silicon oxides (SiO 2 , ,18.5 nm) or clays (,550 nm SWy-2 montmorillonite). Homo-and heteroagglomeration of the nAg were first studied in controlled synthetic waters that were representative of natural fresh waters (50 mg Ag L À1 ; pH 7.0; ionic strength 10 À7 to 10 À1 M Ca) by following the sizes of the nAg by fluorescence correlation spectroscopy. The polyacrylic acid-coated nanosilver was extremely stable under all conditions, including in the presence of other colloids and at high ionic strengths. However, the citrate-coated nanosilver formed heteroaggregates in presence of both colloidal SiO 2 and clay particles. Nanoparticle surface properties appeared to play a key role in controlling the physicochemical stability of the nAg. For example, the polyacrylic acid stabilized nAg-remained extremely stable in the water column, even under conditions for which surrounding colloidal particles were agglomerating. Finally, enhanced dark-field microscopy was then used to further characterise the heteroagglomeration of a citrate-coated nAg with suspensions of colloidal clay, colloidal SiO 2 or natural (river) water.

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Transport of engineered nanoparticles in saturated porous media

Cited by 180 publications

References 48 publications

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Heteroaggregation of nanoparticles with biocolloids and geocolloids

Emerging patterns for engineered nanomaterials in the environment: a review of fate and toxicity studies

Heteroagglomeration of nanosilver with colloidal SiO2 and clay

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