title: Incineration of tannery sludge under oxic and anoxic conditions: study of chromium speciation.
abstract: A tannery sludge, produced from physico-chemical treatment of tannery wastewaters, was incinerated without any pre-treatment process under oxic and anoxic conditions, by controlling the abundance of oxygen. Incineration in oxic conditions was performed at the temperature range from 300°C to 1200°C for duration of 2h, while in anoxic conditions at the temperature range from 400°C to 600°C and varying durations. Incineration under oxic conditions at 500°C resulted in almost total oxidation of Cr(III) to Cr(VI), with CaCrO4 to be the crystalline phase containing Cr(VI). At higher temperatures a part of Cr(VI) was reduced, mainly due to the formation of MgCr2O4. At 1200°C approximately 30% of Cr(VI) was reduced to Cr(III). Incineration under anoxic conditions substantially reduced the extent of oxidation of Cr(III) to Cr(VI). Increase of temperature and duration of incineration lead to increase of Cr(VI) content, while no chromium containing crystalline phase was detected.
authors.affiliation: School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece. Electronic address: pkavo@physics.auth.gr.
authors.forename: P
authors.initials: P
authors.lastname: Kavouras
authors.affiliation: Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece.
authors.forename: E
authors.initials: E
authors.lastname: Pantazopoulou
authors.affiliation: School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: S
authors.initials: S
authors.lastname: Varitis
authors.affiliation: School of Physics, Section of Applied Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: G
authors.initials: G
authors.lastname: Vourlias
authors.affiliation: School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: K
authors.initials: K
authors.lastname: Chrissafis
authors.affiliation: School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: G P
authors.initials: GP
authors.lastname: Dimitrakopulos
authors.affiliation: Department of Chemical Engineering, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: M
authors.initials: M
authors.lastname: Mitrakas
authors.affiliation: Division of Chemical Technology, Department of Chemistry, Aristotle University of Thessaloniki, Thessaloniki GR-54124, Greece.
authors.forename: A I
authors.initials: AI
authors.lastname: Zouboulis
authors.affiliation: School of Physics, Section of Solid State Physics, Aristotle University of Thessaloniki, Thessaloniki 54124, Greece.
authors.forename: Th
authors.initials: T
authors.lastname: Karakostas
authors.affiliation: School of Mining Engineering and Metallurgy, National Technical University of Athens, Zografou Campus, Athens 15780, Greece.
authors.forename: A
authors.initials: A
authors.lastname: Xenidis
mesh_terms: D002857:Chromium / Q000737:chemistry*; D006358:Hot Temperature; D017745:Incineration; D007220:Industrial Waste; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012722:Sewage / Q000737:chemistry*; D013633:Tanning; D014865:Waste Disposal, Fluid / Q000379:methods*
chemical_list: D007220:Industrial Waste; D012722:Sewage; D002857:Chromium; D010100:Oxygen
keywords: Chromium ash; Chromium speciation; Incineration; Tannery sludge