Mechanisms of graphene oxide aggregation, retention, and release in quartz sand

Liang, Yan; Bradford, Scott A.; Šimůnek, Jiřı́; Klumpp, Erwin

doi:10.1016/j.scitotenv.2018.11.258

Cited by 36 publications

(8 citation statements)

References 56 publications

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Section: Profiles Of Retained Particlesmentioning

confidence: 99%

“…The transfer of colloids among collectors was regarded to be those deposited at the secondary energy minimum [24]. The secondary minimum deposition was found to be a major retention mechanism for colloid retention under unfavorable conditions even under high IS conditions [15,17,[64][65][66]. The colloids associated at secondary minima are located at certain distances from the collector surfaces and can translate and rotate along collector surfaces by hydrodynamic shear [47].…”

Section: Profiles Of Retained Particlesmentioning

confidence: 99%

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Transport of Microplastic Particles in Saturated Porous Media

Chu

et al. 2019

Water

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This study used polystyrene latex colloids as model microplastic particles (MPs) and systematically investigated their retention and transport in glass bead-packed columns. Different pore volumes (PVs) of MP influent suspension were first injected into the columns at different ionic strengths (ISs). The breakthrough curves (BTCs) were obtained by measuring the MP concentrations of the effluents. Column dissection was then implemented to obtain retention profiles (RPs) of the MPs by measuring the concentration of attached MPs at different column depths. The results showed that the variation in the concentrations of retained MPs with depth changed from monotonic to non-monotonic with the increase in the PV of the injected influent suspension and solution IS. The non-monotonic retention was attributed to blocking of MPs and transfer of these colloids among collectors in the down-gradient direction. The BTCs were well simulated by the convection-diffusion equation including two types of first-order kinetic deposition (i.e., reversible and irreversible attachment). However, this model could not well simulate the non-monotonic retention profiles due to the fact that the transfer of colloids among collectors was not considered. The results in this study are critical to developing models to simulate the fate and transport of MPs in porous media such as soil.

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Section: Profiles Of Retained Particlesmentioning

confidence: 99%

Section: Profiles Of Retained Particlesmentioning

confidence: 99%

Transport of Microplastic Particles in Saturated Porous Media

Chu

et al. 2019

Water

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“…The presence of phosphates can also increase the surface charge/chemical heterogeneity on the solid–water interfaces. It has been well demonstrated that the surface heterogeneities of colloids and collectors tend to reduce and/or eliminate energy barriers at electrostatically unfavorable locations, thus inhibiting colloid retention [ 51 , 52 , 53 , 54 ]. Consequently, these surface physicochemical heterogeneities can contribute to the significant sensitivity of PNP transport to phosphate concentration and the deviations of DLVO predictions from BTCs.…”

Section: Resultsmentioning

confidence: 99%

“…Analytically pure quartz sand (Tianjin Guangfu Fine Chemical Research Institute, Tianjing, China) was used as porous media. The sand was purified by washing in tap water, followed by soaking in HNO 3 (65%) and H 2 O 2 (10%) for 24 h [ 54 ]. Later, the sand was washed with water again, followed by soaking in 100 mM NaCl and ultrapure water (pH 10) with ultrasonication to remove the potential attached colloidal impurities by cation exchange and expand the electrical double layer.…”

Section: Methodsmentioning

confidence: 99%

Sensitivity of the Transport of Plastic Nanoparticles to Typical Phosphates Associated with Ionic Strength and Solution pH

Liu

Liang

Peng

et al. 2022

IJMS

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The influence of phosphates on the transport of plastic particles in porous media is environmentally relevant due to their ubiquitous coexistence in the subsurface environment. This study investigated the transport of plastic nanoparticles (PNPs) via column experiments, paired with Derjaguin–Landau–Verwey–Overbeek calculations and numerical simulations. The trends of PNP transport vary with increasing concentrations of NaH2PO4 and Na2HPO4 due to the coupled effects of increased electrostatic repulsion, the competition for retention sites, and the compression of the double layer. Higher pH tends to increase PNP transport due to the enhanced deprotonation of surfaces. The release of retained PNPs under reduced IS and increased pH is limited because most of the PNPs were irreversibly captured in deep primary minima. The presence of physicochemical heterogeneities on solid surfaces can reduce PNP transport and increase the sensitivity of the transport to IS. Furthermore, variations in the hydrogen bonding when the two phosphates act as proton donors will result in different influences on PNP transport at the same IS. This study highlights the sensitivity of PNP transport to phosphates associated with the solution chemistries (e.g., IS and pH) and is helpful for better understanding the fate of PNPs and other colloidal contaminants in the subsurface environment.

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“…189) of the flowing solution. However, in the case of rGO, the flowing solution with a higher pH exerted higher mobility due to steric hindrance 187 while GO mobility has been shown to be enhanced under lower IS conditions 184,185,189–191 with one exception where a lower IS resulted in decreased mobility. 188 The presence of organic matter ( e.g.…”

Section: Fate and Transport Of Gnms In Soilmentioning

confidence: 99%