Removal of chromium (VI) from water using nanoscale zerovalent iron particles supported on herb-residue biochar. (15th July 2017)

• Record Type: Journal Article
• Authors: Shang, Jingge; Zong, Mingzhu; Yu, Ying; Kong, Xiangrui; Du, Qiong; Liao, Qianjiahua
• Is Part Of: Journal of environmental management. Volume 197(2017)
• Page Start: 331
• Page End: 337
• Publication Date: 2017-07-15
• Subjects: Biochar -- Herb residue -- Nanoscale zerovalent iron -- Hexavalent chromium -- Co-precipitation; Environmental policy -- Periodicals; Environmental management -- Periodicals; Environment -- Periodicals; Ecology -- Periodicals; 363.705
• DOI: 10.1016/j.jenvman.2017.03.085
• Languages: English
• ISSNs: 0301-4797

Abstract

Abstract: A composite material consisting of nanoscale zerovalent iron particles supported on herb-residue biochar (nZVI/BC) was synthesized and used for treatment of Cr(VI)-contaminated water. The effects of initial pH, chromium concentration, contact time, and competition with coexisting anions and natural organic matter (NOM) were also investigated. nZVI/BC was characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy analysis (SEM), and the Brunauer-Emmett-Teller surface area was measured. TEM and X-ray photoelectron spectroscopy (XPS) analysis before and after reaction with Cr(VI) showed that reduction and coprecipitation occurred during hexavalent chromium adsorption. The removal of Cr(VI) was highly pH-dependent and the adsorption kinetics data agreed well with the pseudo-second-order model. The presence of SO4 2− and humic acid promoted Cr(VI) removal at both low and high concentrations, while the HCO3 − inhibited the reaction. These results prove that nZVI/BC can be an effective reagent for removal of Cr(VI) from solutions. Graphical abstract: Highlights: Nanoscale zerovalent iron was supported on herb-residue biochar. This material was used to remove Cr(VI) from aqueous solutions. Effects of pH, Cr concentration, time, and other anions were investigated. Cr(VI) removal was pH dependent and obeyed pseudo-second-order adsorption kinetics. SO4 2− and humic acid promoted Cr(VI) removal at both low and high concentrations.