Mobilization and deposition of iron nano and sub-micrometer particles (INSMP) in a porous medium were investigated using a water-saturated glass micromodel. The deposition and detachment of INSMP in the micromodel were visualized by taking serial images and experimentally verified by analysis of breakthrough curves. This first visualization study of INSMP fate showed that there were dense aggregations at the pores as the concentration of INSMP increased. The presence of dissolved humic substances (>1. ppm) significantly reduced deposition of suspended particles and enhanced detachment of the deposited particles. The mobility of INSMP in the presence of Pahokee peat fulvic acid standard II (PPFA) was higher than for Pahokee peat humic acid standard I (PPHA) due to the presence of more aromatic groups and the molecular weight in PPFA. Interfacial energy estimation based on the DLVO theory revealed that the adsorption of humic substances onto the INSMP increased the energy barrier and reduced the depth of secondary minimum between particles. The " affinity transition" in the initial deposition of INSMP within the micromodel was observed in the presence of Pahokee peat humic substances.
Bibliographical noteFunding Information:
This work was supported by the National Research Foundation grant funded by the Korea Government ( 2007-0056401 ), and Converging Technology Project funded by Korean Ministry of Environment .
Copyright 2012 Elsevier B.V., All rights reserved.
- DLVO theory
- Glass micromodel
- Humic substances
- Iron nanoparticles
ASJC Scopus subject areas
- Environmental Engineering
- Environmental Chemistry
- Waste Management and Disposal
- Health, Toxicology and Mutagenesis