Total control of chromium in tanneries - thermal decomposition of filtration cake from enzymatic hydrolysis of chrome shavings
This paper deals with the problem of chromium recovery from chrome-tanned waste and thus with reducing the environmental impact of the leather industry. Chrome-tanned waste was transformed by alkaline enzymatic hydrolysis promoted by magnesium oxide into practically chromium-free, commercially appli...
| Veröffentlicht in: | Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA. - 1991. - 35(2017), 4 vom: 08. Apr., Seite 444-449 |
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| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2017
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| Zugriff auf das übergeordnete Werk: | Waste management & research : the journal of the International Solid Wastes and Public Cleansing Association, ISWA |
| Schlagworte: | Journal Article Leather waste alkaline enzymatic hydrolysis chrome shavings chromium filtration cake chromium recycling thermal decomposition Industrial Waste Chromium 0R0008Q3JB |
| Zusammenfassung: | This paper deals with the problem of chromium recovery from chrome-tanned waste and thus with reducing the environmental impact of the leather industry. Chrome-tanned waste was transformed by alkaline enzymatic hydrolysis promoted by magnesium oxide into practically chromium-free, commercially applicable collagen hydrolysate and filtration cake containing a high portion of chromium. The crude and magnesium-deprived chromium cakes were subjected to a process of thermal decomposition at 650°C under oxygen-free conditions to reduce the amount of this waste and to study the effect of magnesium removal on the resulting products. Oxygen-free conditions were applied in order to prevent the oxidation of trivalent chromium into the hazardous hexavalent form. Thermal decomposition products from both crude and magnesium-deprived chrome cakes were characterized by high chromium content over 50%, which occurred as eskolaite (Cr2O3) and magnesiochromite (MgCr2O4) crystal phases, respectively. Thermal decomposition decreased the amount of chrome cake dry feed by 90%. Based on the performed experiments, a scheme for the total control of chromium in the leather industry was designed |
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| Beschreibung: | Date Completed 14.07.2017 Date Revised 14.07.2017 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1096-3669 |
| DOI: | 10.1177/0734242X16680728 |