A NOVEL PICKLE-FREE HIGH EXHAUST CHROME TANNING METHOD - AN APPROACH FOR TOTAL DISSOLVED SOLIDS MANAGEMENT

摘要

Serious environmental concerns are being raised with respect to at high Total Dissolved Solids (TDS) contents in spent leather processing liquors. Pickling alone contributes about 35% TDS in the effluents. As cost effective treatments for TDS are not yet available, in-plant control has become a necessity. In the present work., a pickle-free chrome tanning method has been coupled wilh in-situ neutralisation of acid generated during the hydrolysis of chrome salts. The elimination of pickling has given a significant reduction in TDS. Higher uptake and more uniform distribution of chromium in the leather are other benefits of the process. Chemical, physical and microscopical analyses indicate that the leathers' properties are comparable with those of conventionally processed leathers. It is believed that this new approach could be gainfully employed to overcome the twin concerns of TDS and chromium in the effluent.