Textile waste subjected to acid hydrolysis as raw materials for biogas production

Abstract

Textile waste is a high-volume group of municipal waste that is difficult to dispose of due to synthetic additives and chemicals that give natural fibers the properties preferred by consumers. The paper presents a method of treating textile waste based on natural fibers (cotton and wool) with mineral acids and further biological conversion of obtained hydrolysates into biogas. It was found that the hydrolysates of cotton contain a pool of sugars (≥8 g/L of glucose), which are necessary for the growth of microorganism's consortium. The hydrolysates of the mixture of natural and synthetic fibers do not contain fermentation inhibitors (even when cotton was dotted with polyesters and polyamides), and the addition of an appropriate number of wool hydrolysates (up to 5 % v/v) favours the production of biogas. The results indicate that a moderate methane production from waste textiles composed of both cotton and synthetic materials can be achieved with no need of separation, which would significantly increase the cost of their processing.