Sustainable strategies for the valorization of cotton and cotton blended waste: pathways to circular economy

Abstract This research explores the comparative efficacy of mechanical, chemical, and biological recycling methods for cotton and cotton-based blends, focusing on their processes, challenges, and implications for sustainability. Through detailed analyses of extant literature, this study identified mechanical recycling as a widely implemented method due to its simplicity and cost-effectiveness but notes its limitations, such as fiber degradation, inappropriate for some fibers, and contamination from mixed materials. Chemical recycling is an effective method for recovering fibers that are unsuitable for mechanical recycling, offering high recovery rates and preventing waste being landfilled. Despite its potential, this approach faces challenges such as high energy requirements, financial constraints, and reliance on harsh chemicals. In contrast, biological recycling is emerging as an ecofriendly alternative with the potential to use enzymes for targeted degradation; however, it requires further advancements in enzyme specificity and process scalability. This review emphasizes the need for hybrid models combining these methods to address their individual limitations, such as integrating technological sorting for mechanical recycling or developing non-toxic green solvents for chemical recycling. Furthermore, Life Cycle Assessment comparisons reveal the environmental and financial benefits of optimizing these methods for industrial application, with implications for policymakers and industry stakeholders. By advancing these recycling technologies and aligning sustainable development goals, the cotton textile industry can significantly reduce waste, conserve resources, and foster sustainable practices in waste valorization. Graphical abstract