title: Kaolinite-supported nanoscale zero-valent iron for removal of Pb2+ from aqueous solution: reactivity, characterization and mechanism.
abstract: The use of nanoscale zero-valent iron (nZVI) to remediate contaminated groundwater is limited due to its lack of durability and mechanical strength. To address this issue, 20% (w/w) nZVI was loaded onto kaolinite as a support material (K-nZVI). More than 96% of Pb(2+) was removed from aqueous solution using K-nZVI at an initial condition of 500 mg/L Pb(2+) within 30 min under the conditions of 10 g/L of K-nZVI, pH 5.10 and a temperature of 30 °C. To understand the mechanism of removal of Pb(2+), various techniques were implemented to characterize K-nZVI. Scanning electron microscopy (SEM) indicated that K-nZVI had a suitable dispersive state with a lower aggregation, where the mean specific surface area and average particle size as determined by the BET-N(2) method and X-ray diffraction (XRD), were 26.11 m(2)/g and 44.3 nm, respectively. The results obtained from XRD, X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared (FTIR) indicated that a small number of iron oxides formed on the surface of K-nZVI, suggesting that free Pb(2+) was adsorbed onto K-nZVI and subsequently reduced to Pb(0).
authors.affiliation: School of Chemistry and Materials Sciences, Fujian Normal University, Fuzhou 350007, Fujian Province, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.forename: Shen
authors.initials: S
authors.lastname: Lin
authors.forename: Zuliang
authors.initials: Z
authors.lastname: Chen
authors.forename: Mallavarapu
authors.initials: M
authors.lastname: Megharaj
authors.forename: Ravendra
authors.initials: R
authors.lastname: Naidu
mesh_terms: D007501:Iron / Q000737:chemistry*; D007616:Kaolin / Q000737:chemistry*; D007854:Lead / Q000032:analysis / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008855:Microscopy, Electron, Scanning; D010316:Particle Size; D017550:Spectroscopy, Fourier Transform Infrared; D014874:Water Pollutants, Chemical / Q000032:analysis / Q000737:chemistry*; D018508:Water Purification / Q000379:methods*; D014961:X-Ray Diffraction
chemical_list: D014874:Water Pollutants, Chemical; D007616:Kaolin; D007854:Lead; D007501:Iron