A METHOD FOR THE REMOVAL OF CHROMIUM FROM TANNED LEATHER WASTES

The separation of Cr(III) from collagen in chromium-tanned leather (we t-blue) is achieved by a combination of the protein (collagen) stabili zation (protective crosslinking) and a subsequent labilization of the Cr(III) species bound to the protein. During the separation collagen r etains the tertiary triple helical and higher (fibril) structures. The model proposed for the protective cross-linking involves inter- rathe r than intramolecular bridging, that is, a supramolecular bridging. Th e process of chromium removal takes place in a restricted aqueous envi ronment, and it can be characterized as semihomogeneous or semiheterog eneous.