A novel chrome tanning process for minimization of total dissolved solids and chromium in effluents

Presence of chlorides and chromium in the tannery effluents are serious environmental concerns of leather making. Elimination or minimization of these is active area of global leather research. Treatment system for removal of chlorides from effluents is very expensive and affects seriously the viability of the tanning industry. Long lasting and convincing solution to the problem rests on development of a common salt free tanning system with high chromium exhaustion levels. Common salt, also known as sodium chloride, is most responsible for the salinity in tannery effluents. In this context a new common salt free tanning process has been developed to overcome the stated problems of industrial leather making. The new process affords use of less chromium tanning agents apart from completely eliminating use of common salt in tanning. The reduction in specific consumption of chromium (ton of equivalent chromium per ton of pelts treated) for tanning in the prescribed method provides significant economic benefits to the new process. Substantial reduction of Total Dissolved Solids (TDS) reduction in effluents has been achieved by adopting the new process. The process essentially is based on modification of the reactants activity to ensure high uptake of tanning material. The process also affords uniform distribution of chromium in the leather. The chemical, physical and microscopical analyses indicate comparable leather properties processed by new method when assessed along with conventionally processed leathers. The innovation which has been commercially implemented provides an economical and simple solution to a century old problem. (C) 2013 Elsevier Ltd. All rights reserved.