Millions of tons of textile waste are landfilled or incinerated in the world every year due to insufficient recycle value streams and the complex composition of textile end products. The goal of this review is to highlight pathways for simplifying and separating textile wastes into valuable raw material streams that will promote their recovery and conversion to useful products. The discussion focuses on advances in sorting, separation, decolorization and conversion of polyester and cotton, the two most common textile fibers. Sorting processes are gaining automation using spectroscopic methods that detect chemical composition differences between materials to divide them into categories. Separation, through dissolving or degrading, makes it possible to deconstruct blended textiles and purify polymers, monomers and co-products. Waste cotton can produce high quality regenerated cellulose fibers, cellulose nanocrystals (CNCs) or biofuels. Waste polyester can produce colored yarns or can be chemically converted to its starting monomers for the recreation of virgin polymer as a complete closed loop. The current strategies for decolorization are presented. Life cycle assessment (LCA) studies found that recycling polyester/cotton blended fabrics for subsequent uses is more sustainable than incineration, and research on producing biomass-based poly-ester also offers feasible avenues for improving textile sustainability and promoting circular processing.

Industrial hemp has attracted public attention in recent years since its planting legalization in the United States in 2018. Hemp exhibits unique advantages compared to cotton in sustainability and physical properties such as lower water consumption for cultivation and high tensile strength as a technical fiber. However, due to the complex chemical composition in hemp fiber, traditional hemp fiber processing has required harsh chemicals to remove the impurities, generating undesirable effluents. One approach toward achieving more sustainable hemp fiber production is to lower chemical requirements by employing enzymatic fiber degumming treatments. Natural gums must be removed to achieve high quality spinnable fibers. This review presents a thorough discussion of hemp fiber composition and structure as prerequisites for subsequent discussion of enzyme reactions on three main substrates in the gum—hemicellulose, lignin and pectin. Understanding the specific chemical structure of each substrate is essential for choosing corresponding enzymes for the treatment. The impacts of different enzymatic hemp degumming treatments are compared and their related characterization methods are assessed. As a result, this article provides the hemp industry with structure–function based guidance on degumming hemp with enzymes and offers strategies for establishing green production approaches to achieve sustainability for the industry.