Fabian Garcia Sanchez

Topic

Comparative Batch Evaluation of Hydroxyapatite and Bone Char-Based Products for Fluoride Removal from Groundwater Sources

Department of Civil Engineering

Date & location

• Friday, August 14, 2026

• 9:00 A.M.

• Engineering Computer Science Building

• Room 468 & Virtual Defence

Reviewers

Supervisory Committee

• Dr. Caetano Dorea, Department of Civil Engineering, University of Victoria (Co-Supervisor)

• Dr. Manuel J. Rodriguez, Department of Civil Engineering, UVic (Co-Supervisor) 

External Examiner

• Dr. Rodrigo Moruzzi, Department of Environmental Engineering, São Paulo State University

Chair of Oral Examination

• Dr. Annalee Lepp, Department of Gender Studies, UVic 

Abstract

Fluoride contamination of groundwater is a major public health concern in geogenic high fluoride regions, including parts of the Main Ethiopian Rift, where groundwater is widely used for drinking water and elevated fluoride concentrations have been associated with dental and skeletal fluorosis. The World Health Organization (WHO) guideline value for fluoride in drinking water is 1.5 mg F⁻/L. This thesis evaluates the fluoride removal performance of three hydroxyapatite/bone char (HAP/BC) products, referred to as Product 1, Product 2, and Product 3, using controlled batch experiments with synthetic fluoride solutions at initial concentrations relevant to fluoride-affected Ethiopian groundwater settings. 

Batch experiments were conducted at initial fluoride concentrations of 2.5 and 5.0 mg F⁻/L using a range of adsorbent doses to evaluate product-specific removal behavior, adsorption capacity, and isotherm performance. The three products differed clearly in fluoride uptake. Product 1 showed the highest mean adsorption capacity, followed by Product 2 and Product 3, with average capacities of 1.52, 1.04, and 0.26 mg F⁻/g, respectively. Statistical analysis confirmed significant differences among the products, demonstrating that materials intended for the same defluoridation application should not be assumed to perform equivalently for design purposes. 

Particle size distributions and production differences may have contributed to the observed performance contrasts, although detailed mineralogical and surface-chemistry characterization was beyond the scope of this study. Overall, the findings provide an independent laboratory-based benchmark for locally produced hydroxyapatite/bone char materials and support the need for product-specific evaluation before their use in decentralized defluoridation systems.