The effects of nonionic surfactants on the pretreatment and enzymatic hydrolysis of recycled newspaper

Abstract

The effects of surfactants on the pretreatment and enzymatic hydrolysis stages of recycled newspaper processing were examined. Newspaper substrate was pretreated with surfactants at 40 degrees C and 400 rpm for 1 h, and the enzymatic digestibilities of the pretreated substrate were compared. NP-20 was 10 similar to 20% more effective as a surfactant than Tween-20 and Tween-80. To investigate the effects of the surfactants on the subsequent enzymatic hydrolysis stage, the newspaper was pretreated with NP-20 and then hydrolyzed in the presence of TW-20 or TW-80. TW-80 showed an approximate 7% higher digestibility than TW-20. The surfactant effect on the hydrolysis of the untreated newspaper was significant, whereas the surfactant effect on the hydrolysis of the surfactant-pretreated newspaper was marginal. When the digestibilities of the pure cellulose substrates (alpha-cellulose and filter paper) were examined, markedly different surfactant effects were observed. In contrast to the newspaper substrate, the surfactant-pretreated pure cellulose substrates had a significant effect on digestibility when they were hydrolyzed in the presence of a surfactant, indicating that the surfactant effect on digestibility is highly dependent on substrate type. (c) KSBB.