Green solution for tannery pollution: effect of enzyme based lime-free unhairing and fibre opening in combination with pickle-free chrome tanning

Abstract

Growing global concern on environmental health is forcing all the processing industries to adopt greener and cleaner manufacturing practices. Thus, the leather industry is being pressurized to look for cleaner leather processing. The conventional method of leather making involves do–undo logic. This results in the emission of a huge amount of pollution load such as biochemical oxygen demand (BOD), chemical oxygen demand (COD) and total solids (TS). Currently tanners are looking for design and utilization of cleaner and safer technologies. In this approach, a process has been designed to limit the pH range in leather processing from 13.5–2.8 to 8.0–3.8. An experimental process has been developed by combining enzymatic unhairing, enzyme based fibre opening and pickle and basification free chrome tanning. The experimental tanning process provides comparable leather quality with reduced environmental impact and effluent treatment costs. The process explored also appears to be economically viable.