Recovery of Glucose and Polyester from Textile Waste by Enzymatic Hydrolysis

In order to recover glucose and polyester from textile waste, enzymatic hydrolysis of textile waste pretreated by different modification methods was investigated. The effects of key factors related to hydrolysis process were evaluated, including substrate loading, temperature, pH, cellulase dosage, and supplementation of β-glucosidase. Results showed that freezing NaOH/urea could contribute to significant increase of the hydrolysis yield compared with untreated textile waste, from 57.7 to 98.3%. Increasing substrate loading from 1 to 7% (w/v) had a negative effect on glucose recovery yield and significant inhibitory effect was observed over 3% substrate loading. Substrate loading at 3% was selected based on glucose yield. The optimal temperature for enzymatic hydrolysis was 50 °C and significant reduction was observed over 60 °C. There was no significant increase of glucose recovery yield when cellulase loading was over 20 FPU/g and β-glucosidase loading was over 10 U/g. Therefore, the optimum enzymatic hydrolysis condition was using 20 FPU/g cellulase and 10 U/g β-glucosidase at 50 °C and pH 5, based on the criterion for minimizing enzyme dosage and maximizing glucose recovery. The maximum glucose recovery yield of 98.3% was achieved after 96 h hydrolysis.