title: Pyrolysis Treatment of Chromite Ore Processing Residue by Biomass: Cellulose Pyrolysis and Cr(VI) Reduction Behavior.
abstract: The pyrolysis treatment with biomass is a promising technology for the remediation of chromite-ore-processing residue (COPR). However, the mechanism of this process is still unclear. In this study, the behavior of pyrolysis reduction of Cr(VI) by cellulose, the main component of biomass, was elucidated. The results showed that the volatile fraction (VF) of cellulose, ie. gas and tar, was responsible for Cr(VI) reduction. All organic compounds, as well as CO and H2 in VF, potentially reduced Cr(VI). X-ray absorption near-edge structure (XANES) spectroscopy and extended X-ray absorption fine-structure (EXAFS) spectroscopy confirmed the reduction of Cr(VI) to Cr(III) and the formation of amorphous Cr2O3. The remnant Cr(VI) content in COPR can be reduced below the detection limit (2 mg/kg) by the reduction of COPR particle and extension of reaction time between VF and COPR. This study provided a deep insight on the co-pyrolysis of cellulose with Cr(VI) in COPR and an ideal approach by which to characterize and optimize the pyrolysis treatment for COPR by other organics.
authors: School of Environmental and Municipal Engineering, Qingdao Technological University , Qingdao, Shandong Province 266033 P. R. China.
authors: Da-Lei
authors: DL
authors: Zhang
authors: Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences , Beijing, 100085, P. R. China.
authors: Mei-Yi
authors: MY
authors: Zhang
authors: School of Environmental and Municipal Engineering, Qingdao Technological University , Qingdao, Shandong Province 266033 P. R. China.
authors: Chu-Hui
authors: CH
authors: Zhang
authors: School of Environmental and Municipal Engineering, Qingdao Technological University , Qingdao, Shandong Province 266033 P. R. China.
authors: Ying-Jie
authors: YJ
authors: Sun
authors: School of Environmental and Municipal Engineering, Qingdao Technological University , Qingdao, Shandong Province 266033 P. R. China.
authors: Xiao
authors: X
authors: Sun
authors: Key Laboratory of Biofuels, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences , Qingdao, Shandong Province 266101, P. R. China.
authors: Xian-Zheng
authors: XZ
authors: Yuan
mesh_terms: D018533:Biomass; D002482:Cellulose / Q000737:chemistry*; D002857:Chromium / Q000737:chemistry*; D007220:Industrial Waste; D008669:Metallurgy / Q000379:methods*; D010084:Oxidation-Reduction; D056928:X-Ray Absorption Spectroscopy
chemical_list: D007220:Industrial Waste; D002857:Chromium; C074702:chromium hexavalent ion; D002482:Cellulose