Rationalized method to enhance the chromium uptake in tanning process: role of Gallic acid

In the present study, a greener approach to tanning process based on Gallic acid (GA: Trihydroxybenzoic acid) assisted chrome tanning has been attempted. The exhaustion, the thermal stability, mechanical strength and organoleptic properties of tanned leather as well as the evaluation of eco-friendly characteristics were investigated. The microshrinkage, differential scanning calorimetric and thermo mechanical analyses show the shrinkage temperature, denaturation temperature and % elongation, respectively, of GA-chrome-tanned leather are more than that of chrome alone. Chrome exhaustion greater than 93 % has been achieved. This high exhaust aid offers fullness and softness to leather compared to chrome alone. The environmental impact assessment reveals that the developed high exhaust chrome tanning process is beneficial as significant reduction in total solids content (TSC) such as dissolved solids and suspended solids in the effluent is achieved when compared to tanning with chrome alone. The GA could bring about the enhancement of chromium(III) uptake, significant reduction in TSC resulting in improved environmental, economic and social positive impact.