[article]
| Titre : |
Chromium in the tanning industry : an odissey from cradle to grave |
| Type de document : |
texte imprimé |
| Auteurs : |
Buddhadeb Chattopadhyay, Auteur ; Anulipi Aich, Auteur ; Subhra Kumar Mukhopadhyay, Auteur |
| Année de publication : |
2012 |
| Article en page(s) : |
p. 133-140 |
| Note générale : |
Bibliogr. |
| Langues : |
Anglais (eng) |
| Catégories : |
Chrome hexavalent -- Toxicologie
Cuirs et peaux -- Industrie -- Aspect de l'environnement
Cuirs et peaux -- Industrie -- Inde
Eaux usées
Pollution
Sulfate de chrome
Tannage au chrome
|
| Index. décimale : |
675.2 Préparation du cuir naturel. Tannage |
| Résumé : |
The authors present a review of chromium in the industry together with detailed reports of the remediation of chromium pollution by wetlands.
Chromium is the buzzword of both tanners and environmental scientists. Because ithas several advantageous properties over other tanning agents, 80-90 % of leather today is tanned with chromium salts (Basic Chrome Sulphate). In pre-tanning processes hides and skins are soaked ; hair and keratinous debris in the epidermis are removed and bated. The pelts are then acid pickled to prepare for addition of BCS salts. After full penetration of BCS in the pelts, pH is raised slightly by adding weak alkaline salts. This accelerates the de-protonation of hexaquachromium (III) complexes forming more stable µ-hydroxo-µ-sulphato complexes on one hand and formation of di--tri- or oligo-nuclear complexes by the way of polymerisation on the other. The contemporary process is exclusively based on single bath procedure and utilises Cr(III) only. In contrast, the obsolete double bath process, which involved the insitu reduction of chromate [Cr(VI)], is environmentally and toxicologically hazardous.
The East Calcutta Wetlands ; currently a special conservation site (Ram Site N° 1208), at the eastern fringe of Kolkate city, West Bengal, India was contaminated by composite industrial and municipal wastewater continuously over the past years. A large volume (ca. RO 000m3 day-1) of highly contaminated effluent flows through a network of canals within the ECW ecosystem and are finally discharged into the Kultigong River, nearly 40 kms away from Calcutta city. On the journey through the canals, this composite wastewater is used for irrigating agricultural farms as well as for pisciculture in wastewater-fed fisheries. Chromium, being the most known toxic constituent of tannery effluent drawn the attention of environmental scientists, whether it has any detrimental effect on ecosystem and biota, when the effluent is used for pisciculture and agriculture.
The present study mainly focuses on the adverse effects of chromium, if any, in the abiotic and biotic components of an ecosystem when discharged to the environment. Thought it has been proved that ECW played a crucial role in ameliorating contaminated industrial effluent, thus improving water quality and minimizing the detrimental effects on biota, care still has to be taken to stop insensitive handling and wastage of this valuable mineral resource. In India, the tanning sector inflicts a heavy toll on the chromium resource, as around 30-50 % of chromium that is consumed for leather processing, flows down the drain. It would be our moralduty to check this colossal wastage and think seriously about the recovery and reuse of spent chromium from tanneries. |
| Note de contenu : |
- Chromium : a unique metal of industrial importance
- Chromium and the tanning industry
- Chroium in ecosystems and biota : Chromium in wastewater - Chromium in soil and sediment - Chromium in plants - Chromium in fish - Chromium in non-edible fauna |
| En ligne : |
https://drive.google.com/file/d/1XLjNMGTqow3ODobRAVVAeHhGEbjVVwM5/view?usp=drive [...] |
| Format de la ressource électronique : |
Pdf |
| Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=15697 |
in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC) > Vol. 96, N° 4 (07-08/2012) . - p. 133-140
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Chromium in the tanning industry : an odissey from cradle to grave in JOURNAL OF THE SOCIETY OF LEATHER TECHNOLOGISTS & CHEMISTS (JSLTC), Vol. 96, N° 4 (07-08/2012)
