Lobo, Kieran2025-08-262025-08-262025-08-26http://hdl.handle.net/10393/50797https://doi.org/10.20381/ruor-31347Historically, activated carbon (AC) has been widely used in potable water treatment to remove dissolved organic compounds, including taste and odour-causing compounds, harmful pesticides, and herbicides. Its high specific surface area and extensive pore size distribution give AC a high adsorption capacity for various contaminants. There are numerous long-term drinking water advisories in remote and northern Canadian communities that arise from the significant economic, transportation and logistical challenges in constructing and maintaining water treatment infrastructure. A sustainable solution could be to use white spruce wooden pallets, a common waste in the region, to manufacture AC onsite for use in drinking water treatment. However, the economic and technical constraints necessitate cost-effective and simple methodologies for producing high-performance AC. The primary objective of this thesis is to evaluate the feasibility of producing AC from white spruce wood using phosphoric acid, both with and without three distinct pre-treatment (PT) methods. Part of the novelty of this study is that these PT methods – Torrefaction (TPT), Hydrothermal (HPT) and Alkaline (APT) – have been explored individually in the literature but not comparatively applied to the same materials for this purpose, and this study addresses this gap. A secondary objective is to analyze how these PTs alter the crystalline structure, chemical composition, and macroscopic properties of white spruce wood, and to assess how these changes influence the adsorption capacity and pore size distribution of the resulting ACs. To support the proposed differences in pore development mechanisms, thermogravimetric analysis (TGA) paired with Fourier Transform – Infrared Spectroscopy (FT-IR) was used to analyze the gases produced during the carbonization of phosphoric acid-impregnated samples. The results showed that all the PT methods promoted a greater degree of pore widening during carbonization, enhancing adsorption capacities, specific surface areas and pore volumes compared to the Untreated sample. Remarkably, the PT methods made it possible to produce AC from white spruce wood with iodine adsorption capacities (Iodine Number, IN) and specific surface areas comparable to those of commercial ACs. The enhanced AC properties were accredited to the PTs removing amorphous biopolymers (mainly hemicellulose) from white spruce wood, decreasing the apparent density of the wood leading to increased phosphoric acid activating agent permeation into the wood. This removal increased the crystallinity index (CrI) of the wood, favouring phosphoric acid's reaction with amorphous biopolymers, enhancing pore widening. The different PTs affected crystalline cellulose uniquely, which had the most significant impact on pore development in the ACs. Based on the mean size of cellulose crystallites, it was hypothesized that there was a shift in the dominant mechanism of pore development (acid-catalyzed hydrolysis of biopolymers versus cross-link formation) in AC during carbonization. The change in crystallite size due to HPT caused the greatest increase in specific surface area and adsorption capacity of all ACs produced. HPT slightly increased the size of cellulose crystallites, favouring the development of small mesopores during activation by benefitting from both enhanced acid catalyzed-hydrolysis and cross-link formation. On the other hand, TPT decreased the size of crystallites, leading to somewhat smaller pores in the AC by promoting cross-link formation between the smaller crystallites during activation and limiting acid-catalyzed hydrolysis. APT increased crystallite size to the greatest degree, limiting acid-catalyzed hydrolysis of biopolymers, making the AC slightly more microporous than HPT AC. The pore size distributions of the PT ACs suggest their potential suitability for removing taste and odour-causing compounds, cyanotoxins, and natural organic matter (NOM) in potable water, which are concerns in northern Canadian waters. Ultimately, the study highlights the potentially transformative role that simple PT methods have in optimizing AC adsorption capacity, specific surface area and pore size distribution.enActivated carbon (AC)Adsorption capacitySurface areaPore size distributionPhosphoric acid activationCrystallinity Index (CrI)White spruce woodCellulose crystallite sizeThermogravimetric Analysis (TGA)Fourier Transform Infrared Spectroscopy (FT-IR)Iodine Number (IN)Pre-Treatment (PT)TorrefactionHydrothermalAlkalineWater treatmentThesis