Glutathione enables full utilization of wool wastes for keratin production and wastewater decolorization

Wool waste is the main by-product of the textile industry, which causes environmental problems. Therefore, the recycling of wool waste is of increasing concern and is an important tool for environmental protection and resource-efficient utilization. In this study, an eco-friendly process ensuring complete recycling of wool waste was developed using glutathione as a reducing agent. First, the main component keratin, which is an important source of renewable biomaterial, was extracted. Keratin products were characterized by infrared spectroscopy, Raman spectroscopy, and circular dichroism spectroscopy. The results indicated that glutathione treatment could cause approximately 65% weight dissolution in wool, and keratins with molecular weights of 26, 44, and 66 kDa could be obtained. Furthermore, the residues were collected and prepared as sponges. These sponges showed an excellent adsorption capacity for cationic dye methylene blue (MB). In conclusion, sustainable wool waste recycling coupled with the cleaner production of keratins and a new adsorbent was achieved; this method can turn “waste” into “wealth” and solve the environmental pressures caused by waste. To our knowledge, this is the first report to demonstrate the usefulness of glutathione in an ecofriendly process for the extraction of keratin from wool.