title: Transport characteristics of nanoscale functional zerovalent iron/silica composites for in situ remediation of trichloroethylene.
abstract: Effective in situ remediation of groundwater requires the successful delivery of reactive iron particles through soil. In this paper we report the transport characteristics of nanoscale zerovalent iron entrapped in porous silica particles and prepared through an aerosol-assisted process. The entrapment of iron nanoparticles into the silica matrix prevents their aggregation while maintaining the particles' reactivity. Furthermore, the silica particles are functionalized with alkyl groups and are extremely efficient in adsorbing dissolved trichloroethylene (TCE). Because of synthesis through the aerosol route, the particles are of the optimal size range (0.1-1 microm) for mobility through sediments. Column and capillary transport experiments confirm that the particles move far more effectivelythrough model soils than commercially available uncoated nanoscale reactive iron particles. Microcapillary experiments indicate that the particles partition to the interface of TCE droplets, further enhancing their potential for dense non-aqueous-phase liquid source-zone remediation.
authors.affiliation: Department of Chemical and Biomolecular Engineering, Tulane University, New Orleans, Louisiana 70118, USA.
authors.forename: Jingjing
authors.initials: J
authors.lastname: Zhan
authors.forename: Tonghua
authors.initials: T
authors.lastname: Zheng
authors.forename: Gerhard
authors.initials: G
authors.lastname: Piringer
authors.forename: Christopher
authors.initials: C
authors.lastname: Day
authors.forename: Gary L
authors.initials: GL
authors.lastname: McPherson
authors.forename: Yunfeng
authors.initials: Y
authors.lastname: Lu
authors.forename: Kyriakos
authors.initials: K
authors.lastname: Papadopoulos
authors.forename: Vijay T
authors.initials: VT
authors.lastname: John
mesh_terms: D000327:Adsorption; D000336:Aerosols / Q000737:chemistry; D052918:Environmental Restoration and Remediation; D005374:Filtration; D007501:Iron / Q000737:chemistry*; D009038:Motion; D053761:Nanocomposites / Q000737:chemistry* / Q000648:ultrastructure; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D014241:Trichloroethylene / Q000302:isolation & purification*
chemical_list: D000336:Aerosols; D014241:Trichloroethylene; D012822:Silicon Dioxide; D007501:Iron