China 
Africa 
Explore chapters and articles related to this topic
Phase Interactions in Aquatic Chemistry
Published in Stanley E. Manahan, Environmental Chemistry, 2022
An important influence of colloids in aquatic chemistry is colloid-facilitated transport, their ability to transport contaminants that would otherwise be sorbed to sediments or to aquifer rocks. This mechanism is of concern with respect to subsurface disposal of wastes such as high-level nuclear wastes, including plutonium.3
Phase Interactions in Aquatic Chemistry
Published in Stanley Manahan, Environmental Chemistry, 2017
An important influence of colloids in aquatic chemistry is colloid-facilitated transport, their ability to transport contaminants that would otherwise be sorbed to sediments or to aquifer rocks. This mechanism is of concern with respect to subsurface disposal of wastes such as high-level nuclear wastes including plutonium.2
Numerical analysis of spatial moment for colloid-facilitated contaminant transport through porous media
Published in ISH Journal of Hydraulic Engineering, 2022
Akhilesh Paswan, Pramod Kumar Sharma
Noell et al. (1998) investigated the role of amorphous silica colloids on the transport of cesium using an idealized laboratory set-up. They validated the data with the model developed by Corapcioglu and Jiang (1993). They found reduced retardation of cesium by 14–32% in the 150–210 μm glass bead columns and by 38–51% in the 355–420 μm glass bead columns. The kinetic sorption model suitably described the colloid facilitated transport of cesium compared to the equilibrium model (Noell et al. 1998). Roy and Dzombak (1998) showed the effects of nonequilibrium sorption/desorption on the enhanced transport of hydrophobic organic compounds (HOCs) by colloids in porous media. They applied the model to the laboratory column data for colloid-facilitated transport of a common HOC, phenanthrene. They showed that a significant colloid-facilitated contaminant transport could occur only when the following conditions must satisfy: a quantitatively high colloid concentration, high partition coefficients for contaminant sorption on colloids, and a low deposition rate of colloids.
Influence of humic acid and bovine serum albumin on colloid-associated heavy metal transport in saturated porous media
Published in Environmental Technology, 2022
Wenjie Zhang, Xingzhang Guo, Mohan Jiang
Heavy metal contamination is of considerable concern due to its threat to public health [1,2]. In the past several decades, great attention has been paid to the prediction and assessment of heavy metal transport in subsurface environments. Many laboratory studies have demonstrated that the colloid particles can sometimes enhance or facilitate the transport of heavy metals [3–6]. Heavy metals can transport faster than groundwater flow because colloids can act as carriers of heavy metals [7,8]. Colloid-facilitated transport of heavy metals is one of the reasons for the unexpected concentration and migration distance [9–12]. The transport of the colloid-associated substances in porous media is a complex process involving colloid release, mobilization, entrapment/plugging and adsorption [13–18]. While our knowledge and understanding of the colloid-associated heavy metal transport have been advanced over the last two decades, still more research studies are currently underway concerning many uncertainties involved in the complex process.
Migration of polyethylene glycol coated gold nanoparticles in surrogate natural barriers
Published in Journal of Nuclear Science and Technology, 2020
Carlos Ordonez, Naoko Watanabe, Tamotsu Kozaki
One of the processes that can affect migration behaviors of radionuclides in natural and engineered barriers is colloid facilitated transport. In groundwater systems in and near deep geological repositories, a variety of types of colloidal particles exist with wide size distributions (from ~1 nm to ~1 μm). Colloids can be inorganic, such as common mineral particles (e.g. clay, metal oxides), organic (e.g. humic substances), and microorganisms such as viruses and bacteria [4–10]. In addition, colloidal materials can be produced from the components in the repositories, such as steel canisters, waste glass, bentonite, and concrete through processes such as degradation and/or erosion [11,12]. These colloids can mobilize sorbed radionuclides in groundwater [13]. Experiments performed at the Grimsel Test Site in Switzerland found that radionuclides associated with bentonite colloids migrated without retardation [14]. Field investigations at the Los Alamos site showed that radionuclides associated with colloids were detected over 3 km from the source [15].