Abstract: The present study investigates the use of heavy oil fly ash (HOFA) generated in the power plants as a stabilizer or fill material for various construction activities. In order to recycle the HOFA as fill material, it was mixed with Portland cement at different ratios. Laboratory batch and column experiments were performed on the HOFA and fill materials to investigate the leaching behavior and possible environmental impacts of the potentially hazardous elements such as arsenic (As), cadmium (Cd), cobalt (Co), chromium (Cr), mercury (Hg), nickel (Ni), lead (Pb), copper (Cu), zinc (Zn), selenium (Se), and vanadium (V) within the HOFA. The results showed that leaching of toxic elements from the HOFA can pose toxicity to the environment; while stabilized material prepared by HOFA mixed with 40% cement proved environmentally safe for construction uses.
