1. UKM Learning and Research Repository
2. PHD Thesis / Tesis PHD
3. Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Title:	Effects of nanofiltration variables on recovery of xylitol from fermentation broth model using a newly blended mixed polyethersulfone membranes
Authors:	Khalefa Atya Khalefa Faneer (P75783 )
Supervisor:	Rosiah Rohani, Dr.
Keywords:	Xylitol
Issue Date:	16-Jan-2018
Description:	Xylitol has its privilege due to wide usage in pharmaceutical, food and cosmetic fields. Xylitol is produced either via chemical platform using catalyst or via bioconversion using yeast, fungi or bacteria. The recovery of xylitol from fermentation broth obtained from bioprocess is rather complicated because of the impurities present in the broth. This work was targeted to separate xylitol and impurities in the broth using membrane technology which is efficient and energy saving. Further, utilizing nanofiltration (NF) has proven to be an effective way to remove organic materials such as sugars from sugar alcohol based on the molecular weight of the organics present. In addition, NF membrane is advisable to be used for separating hydrophilic organics such as xylitol. In this work, NF membrane was fabricated using Polyethersulfone (PES) through a wet phase inversion technique. The PES membrane was also incorporated with other co-polymer of Pluronic f127 or nanoparticles (NPs) of TiO2, at different weight percentage in order to recover xylitol effectively. All the pure and blended PES membranes were subjected to series of morphological analyses and characterizations including contact angle, Atomic Force Microscopy (AFM), and Energy-dispersive X-ray spectroscopy (EDX). Response Surface Methodology (RSM) was used to evaluate the xylitol filtration process factors in a modeled fermentation broth. Four factors were set for the Box Behnken design, namely; (i) xylitol concentration: (19 - 88 g/l), (ii) xylose concentration: (1 - 5 g/l), (iii) arabinose concentration: (2 - 25 g/l) and (iv) operating pressure: (4 - 10 bar). All ANOVA models were validated with the correlation p-value of 0.0001. Based on the optimization by the RSM, it is proven that the set factors could give significant effects in the filtration of xylitol mixtures through the membranes. The PES blended with Pluronic 5 % membrane showed an excellent performance in terms of high water flux (maximum at 33 L/m2.h), high xylitol rejection (maximum 90 %) with low arabinose rejection (minimum 50 %) obtained at 79 % membrane porosity and 9.5 nm pore size compared to other fabricated membranes. This membrane also showed high hydrophilicity, which implied good antifouling properties. Fouling results showed that reversible fouling was the dominant after 60 minutes of filtration; furthermore, blending membrane with the additives enhanced the antifouling properties significantly. The highest flux ratio recovery (FRR) was accomplished by PES/Pluronic 5 % membrane at 96 %. Meanwhile, PES composite mixed matrix NPs membranes showed fair water flux and rejection. In conclusion, the recovery of xylitol from fermentation broth using PES/modified membranes is dependent on the concentration of xylitol/sugars where at high concentration of xylitol and low concentration of sugars, high separation performance is achieved. Meanwhile at high concentration of xylitol and also sugars, the membrane has limited separation. The PES/Pluronic 5 % membrane was the best membrane due to high rejection of xylitol at 90 %, low arabinose rejection at 50 %, high FRR at 96.6 % and high hydrophilicity at 61o which implied high antifouling properties.,Ph.D.
Pages:	197
Call Number:	QP702.X89F343 2018 3 tesis
Publisher:	UKM, Bangi
Appears in Collections:	Faculty of Engineering and Built Environment / Fakulti Kejuruteraan dan Alam Bina

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.