title: Mobilization and deposition of iron nano and sub-micrometer particles in porous media: a glass micromodel study.
abstract: 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.
authors.affiliation: School of Environmental Science and Engineering, Gwangju Institute of Science and Technology, 261 Cheomdan-gwagiro, Buk-gu, 500-712 Gwangju, Republic of Korea.
authors.forename: Qiliang
authors.initials: Q
authors.lastname: Wang
authors.forename: Jung-Hyup
authors.initials: JH
authors.lastname: Lee
authors.forename: Seung-Woo
authors.initials: SW
authors.lastname: Jeong
authors.forename: Am
authors.initials: A
authors.lastname: Jang
authors.forename: Sanghyup
authors.initials: S
authors.lastname: Lee
authors.forename: Heechul
authors.initials: H
authors.lastname: Choi
mesh_terms: D001578:Benzopyrans / Q000737:chemistry; D002623:Chemistry Techniques, Analytical; D004867:Equipment Design; D005898:Glass; D060587:Groundwater; D006812:Humic Substances; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D046529:Microscopy, Electron, Transmission / Q000379:methods; D036103:Nanotechnology / Q000379:methods*; D010316:Particle Size; D016062:Porosity; D012987:Soil; D014874:Water Pollutants, Chemical / Q000032:analysis*; D018508:Water Purification / Q000379:methods*
chemical_list: D001578:Benzopyrans; D006812:Humic Substances; D012987:Soil; D014874:Water Pollutants, Chemical; D007501:Iron; C005023:fulvic acid