Abstract

The tanning process generates large amounts of effluents containing chrome(III) and chlorides. This paper deals with a new tanning process based on improving the efficiency of chemical use in order to improve the environmental behaviour of tanneries. This process develops a non-float system with a minimal amount of NaCl, reduced chrome salt addition and increased final tanning temperature at 55°C. The properties of the leathers were similar to those from a traditional process. However, the new process gave 97% less residual chrome and a 95% decrease in the chlorides discharged. Moreover, the new process involves 100% savings in water, about 78% in NaCl and about 32% in Cr2O3 addition. Consequently the process is 55% more cost-effective than the traditional process.