You are encouraged to attend the defence. The details of the defence and attendance information is included below: 

Date: January 14, 2025
Time: 12:00 PM to 2:00 PM (PT)

Defence Mode: Hybrid
In-Person Attendance: Senate Chambers, UNBC Prince George Campus  
Virtual Attendance: via Zoom 

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: APPLICATION OF MODIFIED WALNUT SHELL ADSORBENTS IN PETROCHEMICAL WASTEWATER REMEDIATION

Abstract: Oil spills are of great concern because oily wastewater disrupts the aquatic ecosystem, causes animal mutations, contaminates surface water resources, and causes diseases such as human cancer. Current efforts are geared towards recovering spilled oil from marine environments and ensuring the effective separation of oil and water in the collected emulsion. After oil separation from the emulsion, a polishing step is required to treat the residual oil in the water before discharging the effluent into the aquatic environment. Conventional treatment methods such as in situ burning, mechanical collection, biodegradation and use of chemical dispersant, are intricate and costly, and they achieve varying removal efficiencies (R). Adsorption using environmentally friendly and cost-effective adsorbents is seen as an attractive option. Recent adsorption studies have focused on modifying eco-friendly materials to enhance their adsorption potential.

This study investigated a two-step modification of walnut shells (WS) to treat oily wastewater. Firstly, WS was modified with sodium hydroxide (NaOH) via the wet impregnation method to attain WS/NaOH. Then, tetrabutylammonium bromide (TBAB) was introduced as a co-adsorbent to enhance the oil removal potential of WS/NaOH. The surface morphologies and chemical composition of the WS and WS/NaOH were characterized by scanning electron microscopy (SEM) and Fourier transform infrared (FTIR), respectively. A single-factor experimental design was employed in this study. 

Findings from this research project indicated that RWS and WS/NaOH are excellent adsorbents for the remediation of oily wastewater, with an R of 80.58 % and 87.94 %, respectively. They generated adsorption capacity (q_e) of 201.45 mg/g and 219.85 mg/g respectively. However, with the introduction of TBAB as a co-adsorbent, an R and q_e of 91 % and 226.42 mg/g, respectively, were achieved, proving the effectiveness of TBAB. Adsorption isotherm and kinetic studies were conducted to understand the adsorption mechanism of the proposed adsorbent. It was concluded that the Freundlich and Pseudo second order model best represents the experimental results, as they show higher R² values of 0.8896 and 0.9998, respectively. This research project presents an eco-friendly, cost-effective adsorbent from modified WS to treat oily wastewater, offering a sustainable, scalable alternative to traditional methods by utilizing agricultural waste to remove oil pollutants in petrochemical wastewater treatment efficiently.

Defence Committee:  
Chair: Dr. Erik Jensen, University of Northern British Columbia  
Supervisor: Dr. Oliver Iorhemen, University of Northern British Columbia  
Co-Supervisor: Dr. Jianbing Li, University of Northern British Columbia  
Committee Member: Dr. Natalie Linklater, University of Northern British Columbia  
Committee Member: Dr. Theresa Adesanya , University of Northern British Columbia  
External Examiner: Dr. Pranesh Kumar, University of Northern British Columbia