SUPERVISOR: Thomas ROSENAU 

PROJECT ASSIGNED TO: Jean EGAN

Textile waste is a large global problem, with an estimated 100 million tons disposed of each year, with most ending up in landfills. Despite ~36% of textiles being made of cellulosic material (cotton, viscose, etc.), blends with synthetic fibers (e.g., PET) or chemical additions like colorants and finishing chemicals prevent these textiles from degrading in landfill environments. It has been estimated that if trends continue according to current data, 4.5 Gt of textiles will have accumulated on the planet. Though it is further estimated that up to 60% of textiles are suitable for reuse, there is large portion of textiles that must be disposed of by other sustainable methods, like recycling pathways, to avoid waste accumulation and the other dangers that come with it. One of the major obstacles to textile recycling is fiber blends, as the blends are so intimately twisted together in a fabric that it is nearly impossible to separate them through mechanical means. This project focuses on investigating an enzymatic pathway to efficiently separate cotton from cotton/PET blended pre-consumer textile waste. It will further emphasize the development of an efficient and economically viable process suitable for commercial implementation, which will require investigation into chemical pretreatments of the waste fabric to expedite the hydrolysis of cotton with the enzymes. Enzymatic hydrolysis using cellulases is a highly selective reaction, where the cellulase enzymes only hydrolyze the cotton portion of the textile, leaving a cleaned PET fabric behind. This separation of the two fiber types allows for the creation of two cleaned waste streams: a PET fraction that can be recycled through established methods and a cellulosic pathway consisting of both glucose and recovered cotton fiber fragments. Glucose is a useful platform chemical for the generation of products like bioethanol or other biopolymeric molecules, so its circular potential is well established. The recovered cotton fiber fragments are expected to have value as feedstock for regenerated cellulose fiber production, such as for the creation of lyocell.