Textile production has doubled in the last 20 years, but only 1% is recycled into new fibers. It is the third largest contributor to water pollution and land use, accounting for 10% of global carbon emissions and 20% of clean water pollution. A key challenge in textile recycling is blended yarns, such as polycotton blends, which consist of polyester and cotton. Chemical recycling offers a solution, in particular, alkali treatment, which hydrolyzes polyester (PET) into its components while preserving cotton fibers. However, conventional methods require high temperatures, long durations, or catalysts. Our study presents, for the first time, the heated high-ethanol alkaline aqueous (HHeAA) process that efficiently hydrolyzes PET from polycotton at lower temperatures and without a catalyst. A near-complete PET hydrolysis was achieved in 20 min at 90 °C, while similar results were obtained at 70 °C and 80 °C with longer reaction times. The process was successfully scaled at 90 °C for 20 min, and complete PET hydrolysis was achieved, with a significantly reduced liquid-to-solid ratio, from 40 to 7 (L per kg), signifying its potential to be implemented in an industrial context. Additionally, the cotton maintained most of its properties after the treatment. This method provides a more sustainable and efficient approach to polycotton recycling.

The need for sustainable and efficient water decontamination methods has led to the increasing use of redox enzymes such as glucose oxidase (GOx). GOx immobilization on textile supports provides a promising alternative for catalyzing pollutant degradation in bio-Fenton (BF) and bio-electro-Fenton (BEF) systems. However, challenges related to enzyme stability, reusability, and environmental impact remain a concern. This communication paper outlines innovative strategies developed to address these challenges, notably the use of ecotechnologies to achieve efficient GOx immobilization while maintaining biocatalytic activity. Plasma ecoprocesses, amino-bearing biopolymer-chitosan, as well as a bio-crosslinker genipin have been used efficiently on conductive carbon and non-conductive polyester-PET nonwovens. In certain cases, immobilized GOx can retain high catalytic activity after multiple cycles, making them an effective biocatalyst for organic dye degradation (Crystal Violet and Remazol Blue) via bio-Fenton reactions, including total heterogeneous bio-Fention system. Moreover, the conductive carbon felt-based bioelectrodes successfully supported simultaneous pollutant degradation and energy generation in a BEF system. This work highlights the potential of textile-based enzyme immobilization for sustainable wastewater treatment, bio-electrochemical energy conversion, and also for bacterial deactivation. Future research will focus on optimizing enzyme stability and enhancing BEF efficiency for large-scale applications.

The objectives of this work are to investigate the use of different eco-technologies as strategies for immobilization of redox enzymes on conductive carbon-based felts, to produce bio-functionalized textiles for a future use in sustainable applications while maintaining low environmental impact. Methods using cold remote plasma, electrically conductive biocompatible coating (PEDOT:PSS) and natural crosslinker for the enzyme (genipin) were tested and showed to be efficient in the intended applications. The enzymatic activity of the used glucose oxidase was maintained for multiple number of uses, and showed potential in sustainable wastewater treatment applications in bio-Fenton and bio-electro-Fenton setups. Eco-technology Glucose Oxidase Enzyme Sustainable Wastewater Treatment Plasma COPYRIGHT: © Global Science Press may.kahoush@hb.se (May Kahoush)