Recovery of Wool Fiber from Tannery Solid Waste based on the Comprehensive Analysis of Membership Degree

In order to improve the utilization value of wool fiber in tannery solid waste, this work combined the membership degree comprehensive analysis method with the response surface optimization method to establish the enzymatic recovery process of wool fiber. The membership degree comprehensive analysis method was used to calculate the whiteness, breaking strength, elongation at break, total protein and total sugar content of wool fiber recovered by different enzymatic methods. The comprehensive score S was used as the response value, and the response surface optimization method was used to optimize the ratio of enzyme preparation. Finally, the recovery process of wool fiber was obtained. Specifically, the wool-containing leather solid waste was immersed in a high-temperature water bath at 80 ℃ for 1 h. After cooling, it was immersed in a solution containing 2.5 g/L collagenase, 2.5 g/L trypsin, and 5 g/L bromelain. The pH was adjusted to 7.0 by using NaOH solution, and the enzymatic hydrolysis was performed at 40 ℃ for 5 h. The whiteness of the extracted wool fiber was 61%, and the elongation at break of the fiber was 33%, which was higher than that of the raw wool. The breaking strength of the fiber was 1.08 cN/dteX, which was 96% of the raw wool. This study provides a theoretical reference for the high value research of leather wool solid waste.