An efficient dehairing system supported by oxidative-enzymatic auxiliary towards sustainability

A method of dehairing of goat skins using oxidative chemicals and protease enzymes has been attempted. The dehairing process is one of the important and essential steps in leather making, where hair is removed by lime and sodium sulphide in the conventional process. This conventional dehairing system generates a higher amount of pollution problem as compared to the other unit operations and unit processes. In this work, dehairing of the goat skins through oxidative agents namely magnesium peroxide and protease enzyme has been attempted. For this, protease has been produced from Bacillus sp. at the laboratory level and the activity was found. The dehairing of goat skins takes place for the duration of 14-16 h. The leather produced with the experimental sample showed comparable organoleptic and strength properties with the conventional sample. This method paved the way for the reduction of pollution loads especially BOD, COD, and TDS to the level of 59, 27, and 77%, respectively, in comparison with the control sample. The reaction kinetics for the formation of the ligand-macromolecular complex is found in the isothermal titration calorimetry (ITC) experiment and a mathematical model has been formulated. The dyed crust leather showed comparable colour properties. In addition to that, there is a reduction in processing time for leather making through skipping reliming and deliming processes which are said to be another advantage of this method. The physical strength properties of the experimental leather were also comparable with conventionally produced leather.