Contamination by anionic pollutants, especially fluorides, in the aquatic environment—particularly in drinking water—is a widespread and growing global concern due to its serious health and environmental impacts. Chronic exposure to elevated fluoride levels can lead to dental and skeletal fluorosis, making the development of effective and affordable water treatment solutions an urgent priority. Among various techniques, adsorption using modified activated carbon has emerged as a promising approach for fluoride removal. In this present work, fluoride (F⁻) adsorption on the modified activated carbon (AC@Al(OH)₃) made from date waste and modified commercial activated carbon (ACC@Al(OH)₃) from groundwater have been compared. The effect of adsorbent dose was examined. Al(OH)₃@AC was characterized through Fourier-transform IR spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM). According to the results, the optimum adsorbent dosages were found to be 1.5 g/L for AC@Al(OH)₃ and 2.5 g/L for ACC@Al(OH)₃. Higher adsorption removal for F⁻ on activated carbon prepared from date waste compared with commercial activated carbon was observed. The results of the present study revealed that the produced AC@Al(OH)₃ is a highly promising material for water treatment by effectively removing anionic compounds, particularly fluoride.