Improvement membrane filterability in nanofiltration of prehydrolysis liquor of kraft dissolving pulp by laccase treatment

• Laccase treatment facilitated subsequently nanofiltration by lignin removal.
• Laccase treatment resulted in the increase of membrane filterability.
• Hemicellulosic sugars was concentrated and purified by proposed process.

In this work, laccase treatment was employed to enhance nanofiltration process by lignin removal. Results showed that the membrane filterability was increased in terms of deionized water flux and PHL filtration process. On the other hand, the hemicellulosic sugars were negligible affected and can be concentrated to 172 g/L, which was increased about 300% from the original one. The combined laccase-nanofiltration process provides an alternative approach to utilize hemicellulosic sugars of PHL in an environmentally friendly way.