Relationships between Concentrated H3PO4 Pretreatment Conditions and Substrate Concentration in High Solid Enzymatic Hydrolysis of Pretreated Waste Cotton-based Textiles
CAI Jun-zhuo DONG Zhu-jun QIU Jing-wen SHI Yu SHEN Fei
College of Resource and Environment, Sichuan Agricultural University College of Resource and Environment, Sichuan Agricultural University College of Resource and Environment, Sichuan Agricultural University College of Resource and Environment, Sichuan Agricultural University College of Resource and Environment, Sichuan Agricultural University
Abstract: In order to seek an efficient utilization way for waste cotton-based textiles, concentrated H3PO4 pretreatment was employed to regenerate cellulose for glucose production by enzymatic hydrolysis. The relationships of pretreatment temperature, time and H3PO4 concentration with substrate concentration for high solid enzymatic hydrolysis were investigated. The results indicated that the positive linear relationships existed in the pretreatment temperature, time and the substrate concentration. Based on glucose conversion of 70.0% as a criterion for high efficient hydrolysis, the potential substrate concentration could be improved from 4.6% to 18.0% as temperature was promoted from 30℃ to 60℃. When pretreatment time was prolonged from 3.0 to 12.0 h, the potential substrate concentration was correspondingly enhanced from 10.8% to 25.1%. However, excessive pretreatment time was not beneficial to the enhancement of potential substrate concentration. H3PO4 concentration could not greatly improve the potential substrate consistency in the range of 77.5%~82.5% except that 17.6% substrate concentration could be achieved at 85%. As a result, the maximum potential substrate concentration of 25.1% was achieved as the waste cotton-based textiles were pretreated at 60℃ with 85.0% H3PO4 for 12.0 h.