Transport of CMC-Stabilized nZVI in Saturated Sand Column: the Effect of Particle Concentration and Soil Grain Size

Saberinasr, Amir; Rezaei, Mohsen; Nakhaei, Mohammad; Hosseini, Seiyed Mossa

doi:10.1007/s11270-016-3097-3

Cited by 26 publications

(9 citation statements)

References 57 publications

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“…This is a typical shape for BTCs of the transport of solutes/particles present in large concentrations. These results are consistent with previous reports of a larger release and higher RC of CMC-nZVI particles in case of larger particle concentrations [40]. The RC of CMC-nZVI particles was always larger at pH 9 as compared to RC at pH 7.…”

Section: Effect Of Cmc Polymer Stabilizer and Ph On The Transport Of supporting

confidence: 92%

Effect of Flow Rate and Particle Concentration on the Transport and Deposition of Bare and Stabilized Zero-Valent Iron Nanoparticles in Sandy Soil

et al. 2019

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Efficient application of nanoscale zero-valent iron (nZVI) particles in remediation processes relies heavily on the ability to modify the surfaces of nZVI particles to enhance their stability and mobility in subsurface layers. We investigated the effect of sodium carboxy-methyl-cellulose (CMC) polymer stabilizer, pH, particle concentration, and flow rate on the transport of nZVI particles in sand columns. Breakthrough curves (BTCs) of nZVI particles indicated that the transport of nZVI particles was increased by the presence of CMC and by increasing the flow rate. The relative concentration (RC) of the eluted CMC-nZVI nanoparticles was larger at pH 9 as compared to RC at pH 7. This is mainly attributed to the increased nZVI particle stability at higher pH due to the increase in the electrostatic repulsion forces and the formation of larger energy barriers. nZVI particle deposition was larger at 0.1 cm min −1 flow due to the increased residence time, which increases the aggregation and settlement of particles. The amount of CMC-nZVI particles eluted from the sand columns was increased by 52% at the maximum flow rate of 1.0 cm min −1 . Bare nZVI were mostly retained in the first millimeters of the soil column, and the amount eluted did not exceed 1.2% of the total amount added. Our results suggest that surface modification of nZVI particles was necessary to increase stability and enhance transport in sandy soil. Nevertheless, a proper flow rate, suitable for the intended remediation efforts, must be considered to minimize nZVI particle deposition and increase remediation efficiency.

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Section: Effect Of Cmc Polymer Stabilizer and Ph On The Transport Of supporting

confidence: 92%

Effect of Flow Rate and Particle Concentration on the Transport and Deposition of Bare and Stabilized Zero-Valent Iron Nanoparticles in Sandy Soil

et al. 2019

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“…The mobility of viruses and bacteria in the subsurface is an important concern in groundwater extraction (Chrysikopoulos et al., 2010; Harvey & Garabedian, 1991; Torkzaban, 2007; Zhang et al., 2012). The delivery of injected nanomaterials such as nano zero‐valent iron to contaminated groundwater sites has a significant impact on remediation efficiency (Mueller et al., 2012; Saberinasr et al., 2016).…”

Section: Introductionmentioning

confidence: 99%

Simulation of Colloid Transport and Retention Using a Pore‐Network Model With Roughness and Chemical Heterogeneity on Pore Surfaces

Lin

Bradford

et al. 2021

Water Resources Research

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Colloid transport and retention in porous media is a common phenomenon in both nature and industry. However, many questions remain on how to obtain colloid transport and retention parameters. Previous work usually assumed constant transport parameters in a medium under a given physicochemical condition. In this study, pore‐network modeling is employed to upscale colloid transport and retention from the pore‐scale to the macro‐scale. The pore‐scale transport parameters including the collection efficiency (η), the sticking efficiency (α), and the fraction of the solid‐water interface that contributes to the colloid attachment (Sf) are obtained using numerical simulation and probability analysis for each pore throat. The influence of roughness and charge heterogeneity on the distribution of pore‐scale parameters is discussed. Breakthrough curves and the retention profiles under different roughness and charge heterogeneity conditions are also analyzed. Results show that pore‐scale parameters η, α, and Sf have various distributions in porous media that may not be accurately described using single‐valued effective parameters. The value of η decreases with velocity and exhibits a wide distribution under low‐velocity conditions. The parameter α tends to decrease with the colloid size and the pore water velocity and increased with the charge heterogeneity fraction. Nanoscale roughness alters α in a non‐monotonic fashion but tends to increase for lower roughness fractions and zeta potential. Microscopic roughness increases values of α for colloids that would otherwise be susceptible to hydrodynamic removal. Breakthrough curves and retention profiles show that more retention occurs for smaller particles, which reflects the influence of blocking.

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“…Several methods have therefore been developed to enhance the mobility of nZVI, such as the use of supporting polymers (Elliott & Zhang, 2003;Kanel, Goswami, Clement, Barnett, & Zhao, 2008;Kocur et al, 2014) or emulsifier (Su et al, 2013;Zhang, Dong, Gao, Cai, & Dong, 2019). Furthermore, researchers have investigated the influence of physical factors of the aquifer (such as soil grain size, groundwater velocity, and injection model) and geochemical conditions (such as solute concentration and humic acid) of groundwater to optimize the mobility of nZVI (Dong & Lo, 2014;Jiemvarangkul, Zhang, & Lien, 2011;Li, Zhao, Han, & Hong, 2015;Saberinasr, Rezaei, Nakhaei, & Hosseini, 2016;Saleh et al, 2008).…”

Section: Introductionmentioning

confidence: 99%

Impact of phosphate adsorption on the mobility of PANI‐supported nano zero‐valent iron

Lin

Bradford

et al. 2021

Vadose Zone Journal

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Nano zero-valent iron (nZVI) has been used for in situ groundwater remediation due to its strong adsorption and reaction characteristics. However, oxyanion contaminants in groundwater can ready adsorbed onto the surface of nZVI. This can potentially alter the mobility of nZVI and create a secondary pollution source, but these issues have not yet been systematically investigated. In this study, polyaniline-supported nZVI (PnZVI) and phosphate-sorbed PnZVI (PS-PnZVI) were synthesized in the laboratory. The sedimentation and transport behavior of these two nZVI particles were investigated, compared, and mathematically modeled to better understand the impact of phosphate adsorption on these processes. Results showed that phosphate adsorption can enhance the stability and mobility of PnZVI. Interaction energy calculations that considered van der Waals and magnetic attraction, electrostatic double layer and Born repulsion, and the influence of nanoscale roughness and binary charge heterogeneity were conducted to better infer mechanisms causing nZVI particle sedimentation and retention. Nanoscale roughness and binary charge heterogeneity were found to significantly decrease the energy barrier, but not to low enough levels to explain the observed behavior. The rapid settling of PnZVI was attributed to strong magnetic attraction between particles, which produced rapid aggregation and retention due to straining and/or hydrodynamic bridging. Phosphate adsorption enhanced the mobility of PS-PnZVI in comparison with PnZVI due to a decrease in particle size and aggregation, and an increase in the energy barrier with the porous media. A potential risk of nZVI particles to facilitate oxyanion contaminant transport was demonstrated for phosphate.

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Transport of CMC-Stabilized nZVI in Saturated Sand Column: the Effect of Particle Concentration and Soil Grain Size

Cited by 26 publications

References 57 publications

Effect of Flow Rate and Particle Concentration on the Transport and Deposition of Bare and Stabilized Zero-Valent Iron Nanoparticles in Sandy Soil

Effect of Flow Rate and Particle Concentration on the Transport and Deposition of Bare and Stabilized Zero-Valent Iron Nanoparticles in Sandy Soil

Simulation of Colloid Transport and Retention Using a Pore‐Network Model With Roughness and Chemical Heterogeneity on Pore Surfaces

Impact of phosphate adsorption on the mobility of PANI‐supported nano zero‐valent iron

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