Thesis Defence: Manveer Kaur (Master of Applied Science in Engineering)
You are encouraged to attend the defence. The details of the defence and attendance information is included below:
Date: April 10, 2025
Time: 2:00 PM to 4:00 PM (PT)
Defence mode: Remote
Virtual Attendance: via Zoom (additional Zoom details at bottom of message)
LINK TO JOIN: Please contact the Office of Graduate Administration for information regarding remote attendance for online defences.
To ensure the defence proceeds with no interruptions, please mute your audio and video on entry and do not inadvertently share your screen. The meeting will be locked to entry 5 minutes after it begins: please ensure you are on time.
Thesis entitled: OPTIMIZATION OF XANTHAN BIOSYNTHESIS IN THE GRANULE MATRIX IN AEROBIC GRANULAR SLUDGE WASTEWATER TREATMENT SYSTEMS
Abstract: The aerobic granular sludge (AGS) biotechnology provides the opportunity to recover resources such as phosphorus, alginate-like exopolysaccharides, polyhydroxyalkanoates, tryptophan, etc. from wastewater. Recently, xanthan, a versatile biopolymer with applications in the food, oil, geotechnical, and biomedical industries, has been identified in the aerobic granule matrix. The production of xanthan from waste is encouraged because conventional processes for its production are costly and require specialized laboratories. This study aimed at optimizing key process parameters such as organic loading rate (OLR), chemical oxygen demand to nitrogen (COD/N) ratio, and feeding strategy to enhance xanthan biosynthesis in aerobic granule matrix in AGS-based wastewater treatment systems. The research explores how these parameters influence microbial activity, substrate utilization, and the stability of the granule matrix while ensuring effective wastewater treatment. Using Taguchi fractional factorial design, nine experimental runs were conducted to evaluate the effects of these parameters on xanthan production. Results indicated that a moderate COD/N ratio (10-20) and higher OLR (≥2.0 kg COD/m³∙d) favor increased xanthan yields, with a peak production of approximately 45 mg xanthan/g biomass observed under optimal conditions. In contrast, low OLR (0.8 kg COD/m³∙d) and high COD/N ratios (≥30) significantly reduced xanthan biosynthesis, likely due to nutrient imbalances and substrate limitations. The feeding strategy had a negligible impact on production, as confirmed by the Taguchi mean effect analysis. Pearson correlation analysis identified OLR and COD/N ratio as key factors affecting xanthan production in AGS bioreactors. A strong positive correlation (r = 0.831) was obtained between OLR and xanthan yield which indicates that higher OLR enhances production. A moderate negative correlation (r = -0.512) was obtained between COD/N and xanthan yield which suggests that increased COD/N ratios reduce yield. The feeding strategy showed minimal influence on xanthan yield (r = 0.042). These findings contribute to optimizing AGS systems for sustainable xanthan recovery from wastewater, offering an efficient alternative for biopolymer production.
Defence Committee:
Chair: Dr. Michel Bouchard
Supervisor: Dr. Oliver Iorhemen
Committee Member: Dr. Jianbing Li
Committee Member: Dr. Kalindi Morgan
External Examiner: Dr. Jonathan Cale
Contact Information
Graduate Administration in the Office of the Registrar, University of Northern British Columbia