Leather shavings treatment - an enzymatic approach

The present work is devoted to illustrating the potential application of enzymes for recycling wet-blue shavings. Two approaches were made in parallel. To recycle wet-blue shavings, the classical method uses grinding, followed by agglomeration and drying. In the present work, grinding was not done, instead an acidic protease-pepsin was used followed by a cross-linking with glutaraldehyde. The resultant paste was then pressed and dried. Practically no chromium was released to the aqueous medium. The agglomerate proved to be useful in shoemaking. The second approach made use of an alkaline protease which completely digested the wet-blue shavings and separated the chromium from the leather. The chromium could then be removed and the protein hydrolysate used as a replacement product for hide finishing. Pilot assays demonstrated the viability of this technology for the leather industry. The work follows from that reported in Unhairing with Enzymes-see JSLTC, 2003. 87, p198