Enzymatic hydrolysis and mechanical recycling as alternatives for the reduction of cotton/polyester textile waste

Abstract

The concern with the generation and disposal of waste inappropriately is contemporary to society, resulting in the search for alternatives to mitigate its impacts. Data from 2021 indicate that the Brazilian textile industry produced 170,000 tons of waste annually, of which 80% was sent to landfills and dumps. The low recycling rate for this type of waste is due, among several aspects, to the difficulty in the recycling process, highlighting the separation of existing materials in the mixed fabric that are intrinsically intertwined. Thus, in this project we intend to study the appropriate parameters for the separation of the polyester/cotton fabric in two sequential processes: (1) enzymatic hydrolysis and (2) mechanical recycling. In the first will occur the hydrolysis of the cotton from cellulases isolated from the fungus L. theobromae, to obtain glucose and, with the second the recycling of the polyester. Performing the enzymatic hydrolysis, the cotton fibres will degrade until glucose is obtained, leaving the polyester, which will be submitted to the mechanical recycling, with addition of a functional molecule, called carbodiimide for modulation of its molar mass and consequently, of its properties.