Single pot low float chromium tanning: Cleaner pathway approach to environment friendly leather manufacturing

Chromium tanning is the most essential and extensively used tanning process in leather manufacture that requires pre and post-treatment steps such as pickling and basification to stabilize the collagen in the skin matrix. The conventional chromium tanning process results in low chromium uptake. The unabsorbed chemicals end up in the effluent, directly affecting the environment. Stringent norms have been stipulated for the disposal of effluents containing chromium, total dissolved solids and chlorides, forcing tanners to explore low-waste and cleaner chromium tanning processes. A chemical mixture was formulated to overcome the issues associated with chromium tanning process, which leads to pickle and basification free single pot chromium tanning. The designed process reduces effluent load generation exhibiting nearly 99% chromium uptake, while the conventional chromium uptake is only about 69%. The experimental process results in more than 99% reduction in TDS, chlorides, and COD load compared to the conventional tanning process. Also, the experimental leather possesses good thermal stability and physical strength comparable to the conventional leathers. Thus, the present research work provides an option for cleaner tanning technology to reduce water and chemical load, and the system is environmentally friendly.