The role of temperature on Cr(VI) formation and reduction during heating of chromium-containing sludge in the presence of CaO

• Published in: Chemosphere (Oxford) Vol. 138; pp. 197 - 204
• Main Authors: Mao, Linqiang, Gao, Bingying, Deng, Ning, Zhai, Jianping, Zhao, Yongbin, Li, Qin, Cui, Hao
• Format: Journal Article
• Language: English
• Published: England Elsevier Ltd 01.11.2015
• Subjects: calcium; Calcium Compounds - chemistry; calcium oxide; Calorimetry; CaO; Chromium; Chromium - analysis; Chromium-containing sludge; Formations; heat; heat treatment; Heating; Heating time; intermediate product; leaching; Magnesium oxide; oxidation; Oxidation-Reduction; Oxides - chemistry; Phase Transition; Reduction; Sewage - chemistry; Sludge; Temperature; Temperature dependence; thermal properties; Thermal treatment; Thermodynamics; Thermogravimetry; Waste Water - chemistry; Water Pollutants, Chemical - analysis; X-radiation; X-Rays; CaO; Chromium-containing sludge; Temperature; Heating time; Thermal treatment
• ISSN: 0045-6535; 1879-1298; 1879-1298
• DOI: 10.1016/j.chemosphere.2015.05.097

[Display omitted] •CaO results in Cr(III) being oxidized to Cr2O3+x annealed at 200–400°C.•Most of Cr2O3+x would be reduced into Cr2O3 over 400°C.•Part of CaCrO4 is reduced to Ca(CrO2)2 at 1000–1200°C.•Ca(CrO2)2 is oxidized reversibly to CaCrO4 annealed at 1200°C over 1h. In this study, the temperat...