title: Removal of hexavalent chromium in soil and groundwater by supported nano zero-valent iron on silica fume.
abstract: Silica fume supported-Fe(0) nanoparticles (SF-Fe(0)) were prepared using commercial silica fume as a support. The feasibility of using this SF-Fe(0) for reductive immobilization of Cr(VI) was investigated through batch tests. Compared with unsupported Fe(0), SF-Fe(0) was significantly more active in Cr(VI) removal especially in 84 wt% silica fume loading. Silica fume had also been found to inhibit the formation of Fe(III)/Cr(III) precipitation on Fe nanoparticles' surface, which was increasing the deactivation resistance of iron. Cr(VI) was removed through physical adsorption of Cr(VI) onto the SF-Fe(0) surface and subsequent reduction of Cr(VI) to Cr(III). The rate of reduction of Cr(VI) could be expressed by pseudo first-order reaction kinetics. The rate constant increased with the increase in iron loading but decreased with the increase in initial Cr(VI) concentration. Furthermore, column tests showed that the SF-Fe(0) could be readily transported in model soil.
authors: College of Environmental Science and Engineering, Nankai University, Tianjin 300071, People's Republic of China.
authors: Yongchao
authors: Y
authors: Li
authors: Zhaohui
authors: Z
authors: Jin
authors: Tielong
authors: T
authors: Li
authors: Shujing
authors: S
authors: Li
mesh_terms: D002857:Chromium / Q000302:isolation & purification*; D052918:Environmental Restoration and Remediation / Q000379:methods; D005240:Feasibility Studies; D005618:Fresh Water / Q000737:chemistry*; D007501:Iron / Q000737:chemistry*; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D053758:Nanoparticles; D010316:Particle Size; D012822:Silicon Dioxide / Q000737:chemistry*; D012989:Soil Pollutants / Q000302:isolation & purification*; D013499:Surface Properties; D014874:Water Pollutants, Chemical / Q000302:isolation & purification*
chemical_list: D012989:Soil Pollutants; D014874:Water Pollutants, Chemical; D002857:Chromium; C074702:chromium hexavalent ion; D012822:Silicon Dioxide; D007501:Iron