Optimization of the aqueous degreasing process with enzymes and its influence on reducing the contaminant load

In this work, a degreasing process using an ethoxylated fatty alcohol has b een applied to pickled English domestic sheepskins. A standard substrate ha s been used to determine the best degreasing conditions as a function of pH , surfactant offer, degreasing time and treatment with lipases which are ac tive at neutral pH. Once determined, the degreasing conditions have been applied to whole skins . The influence of adding acid proteases and acid lipases during the pickle process and that of adding neutral lipases during the degreasing treatment has been studied. Given that, the higher the degreasing effectiveness, the higher the COD values of the degreasing effluents, the surfactant offer ha s been optimized to improve degreasing effectiveness with as little polluti on as possible. The effect of the addition of enzymes on degreasing effecti veness has been compared to that produced by implementing degreasing proces ses with a pre-tanning operation. An aqueous degreasing process with enzyme addition for wooled English domes tic sheepskins for "double face" leather articles is recommended.