Oral
Abstract
Research summary supplied by the authors
Enzymatic unhairing is an alternative to traditional sulfide -based unhairing processes in leather manufacture to achieve sustainable and cleaner methods. The leather manufacturers poised forward - thinking strategy to replace conventional methods. However, there are a series of challenges due to the sulfide-based unhairing methods, such as hair burning and emission of toxic gas. Introducing enzymes for unhairing process is the vision pursued by researchers for decades during leather production that eliminates sulfide use. Our recent project work on The Green Tannery Initiative: Enzymatic Unhairing and Sustainable Waste Utilization in Ethiopia's Leather Sector under Sustainable Manufacturing Environmental Pollution (SMEP) programme, commercial unhairing enzymes have been screened and chosen to standardize the enzymatic unhairing processes for Ethiopian raw materials. Pilot-scale trials were carried out using drum method for cattle hides and paste and drum methods for sheep skins. The trials achieved complete hair recovery, enabling valorization of hair and fleshing waste into high- value by-products. The enzymatic process led to 100% elimination of sulfide, significant reduction in COD and TSS, with enhanced grain quality. The optimized enzymatic unhairing was completed within 12 hours, demonstrating both environmental and operational feasibility. This paper will detail the optimized parameters for enzymatic unhairing of Ethiopian raw materials, compare the results with the conventional lime-sulfide process, and highlight the techno-commercial and environmental benefits of adopting enzyme-based systems as a sustainable pathway for leather production in Ethiopia.