title: Column study for the evaluation of the transport properties of polyphenol-coated nanoiron.
abstract: Injection of a nano zero valent iron (nZVI) suspension in the subsurface is a remedial option for obtaining the in situ reduction and immobilization of hexavalent chromium in contaminated aquifers. Prerequisite for the successful implementation of this technology is that the nanoparticles form a stable colloidal suspension with good transport properties when delivered in the subsurface. In this study we produced stable suspensions of polyphenol-coated nZVI (GT-nZVI) and we evaluated their transport behavior through representative porous media. Two types of porous materials were tested: (a) silica sand as a typical inert medium and (b) a mixture of calcareous soil and sand. The transport of GT-nZVI through the sand column was effectively described using a classic 1-D convection-dispersion flow equation (CDE) in combination with the colloid filtration theory (CFT). The calculations indicate that nZVI travel distance will be limited in the range 2.5-25cm for low Darcy velocities (0.1-1m/d) and in the order of 2.5m at higher velocities (10m/d). The mobility of GT-nZVI suspension in the soil-sand column is lower and is directly related to the progress of the neutralization reactions between the acidic GT-nZVI suspension and soil calcite.
authors: School of Mining and Metallurgical Engineering, National Technical University of Athens, 15780, Greece. Electronic address: chmistrioti@metal.ntua.gr.
authors: C
authors: C
authors: Mystrioti
authors: School of Mining and Metallurgical Engineering, National Technical University of Athens, 15780, Greece.
authors: N
authors: N
authors: Papassiopi
authors: School of Mining and Metallurgical Engineering, National Technical University of Athens, 15780, Greece.
authors: A
authors: A
authors: Xenidis
authors: School of Civil Engineering, National Technical University of Athens, 15780, Greece.
authors: D
authors: D
authors: Dermatas
authors: Department of Civil and Environmental Engineering, University of Connecticut, Storrs CT 06269 USA.
authors: M
authors: M
authors: Chrysochoou
mesh_terms: D002119:Calcium Carbonate / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D059808:Polyphenols / Q000737:chemistry*; D012822:Silicon Dioxide / Q000737:chemistry; D012987:Soil / Q000737:chemistry
chemical_list: D059808:Polyphenols; D012987:Soil; D012822:Silicon Dioxide; D007501:Iron; D002119:Calcium Carbonate
keywords: Iron nanoparticles; Mobility; Soil calcite; Soil remediation; Transport