[article]
| Titre : |
Alternative process for recovery of chrome(III)-effluents |
| Type de document : |
texte imprimé |
| Auteurs : |
Jaime Cot, Auteur ; Agusti Marsal, Auteur ; Albert M. Manich, Auteur ; Pedro J. Celma, Auteur ; F. Fernandez, Auteur ; J. Cot-Gores, Auteur |
| Année de publication : |
2008 |
| Article en page(s) : |
p. 139-149 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Bisulfite de sodium
Eaux usées -- Epuration
Eaux usées -- Teneur en chrome
Fluidisation
Glucose
Gommes et résines
Oxydoréduction
Peroxyde d'hydrogèneLe peroxyde d'hydrogène (H2O2), communément appelé eau oxygénée ou encore perhydrol (appellation industrielle), est un composé chimique liquide et visqueux, aux puissantes propriétés oxydantes (il est aussi réducteur). C'est donc un agent blanchissant efficace qui sert de désinfectant et (à haute concentration) d'oxydant ou monergol dans les fusées spatiales.
Récupération (Déchets, etc.)
|
| Index. décimale : |
675 Technologie du cuir et de la fourrure |
| Résumé : |
This scheme aims to set up an alternative process to recover chrome(III) from tannery effluents. The use of the conventional technique of alkaline precipitation (magnesium oxide) of chromium(III) is well known from the literature and is in daily practice in tanneries worldwide. This technique may in fact represent the cheapest treatment nowadays; however, the latest economic studies have revealed the influence of parameters that could significantly alter investment costs and thus open a door to alternative processes. The main problems that the precipitation technique carries with it are :
- a) the presence of highly masked chrome(III) complexes, difficult to precipitate even in alkaline medium.
- b) the speed of precipitation and the density of the precipitate can be a major problem. Sometimes, the application of heat is required.
- c) filtration of the precipitate and subsequent drying to remove possibly 30% of the water content of the chromecake (various techniques are used).
- d) recovered chrome(III) obtained by re-dissolving the cake with sulphuric acid and final adjustment to 33°Sch basicity can occlude large amounts of highly masked chrome (III) complexes which, in turn, produce uneven dyed grain surfaces ; limiting dyeing to dark shades.
Furthermore, basic factors such as energy consumption, the lengthy nature of the overall process, the simple but numerous stages, and limited coverage of fashion colours indicate that an alternative process is possible.
This part of the work aims to recover the chromium1 of wastewater coming from the various chrome using processes and, at the same time, to get an effluent that can be used directly without complementary treatments. It is important to give a clearer and detailed idea of the developed process. |
| Note de contenu : |
- INTRODUCTION : Resin selection - Wastewater oxidation process - Wastewater loading - Chromium reduction process
- EXPERIMENTAL PROCEDURE : Equipment and reagents used - Resin Amberlite IRA-96 - Sample preparation - Wastewater load and reduction - Fluidisation system - Fluidisation mechanism (see appendix for symbols) - Calculation off luidisation for the pilot plant - Reduction in a batch system
- Table 1 : Amberlite IRA-96 resin characteristics
- Table 2 : Optimal operation conditions
- Table 3 : Chromium recovered using acid hydrogen peroxide as reducer
- Table 4 : Chromium recovered using sodium bisulphite as reducer
- Table 5 : Chromium recovered using glucose as reducer |
| En ligne : |
https://drive.google.com/file/d/1k7CnOQf4zEsbildKyaGXxsI_elC93m2i/view?usp=share [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=38963 |
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 92, N° 4 (07-08/2008) . - p. 139-149
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