Abstract

As a substitute for lime, a novel liming agent based on sodium silicate and enzyme was applied in a lime-free liming process. This innovative process achieved an equivalent effect on fibre opening, shrinkage temperature (Ts) and mechanical properties of crust leather compared with a conventional liming process. The environmental factors, including total solids (TS), chemical oxygen demand (COD), sludge concentration and biodegradability of wastewater were all superior to the conventional liming process, showing environmental-friendly characteristics. Another interesting phenomenon was that the traditional deliming process based on ammonium salt could be omitted. As a result, the NH3-N concentration in wastewater was greatly reduced and there is a large water saving.