Background:The water pollution of Tigris River is considered the main increasing problem in Mosul city, Iraq. The divalent lead ions are direct or indirect toxic heavy metals ions contaminant confirmed as non-biodegradables and have a long half-life due to corrosions and sedimentation of these metal ions in storm sewer trunk mains, the critical issue is eliminating these heavy metal ions by treating wastewater via commercial activated carbon (CAC), which is the most effective used adsorbent in the adsorption process. Aim: This study aimed to eliminate divalent lead ions by treating wastewater using commercial activated carbon (CAC). Methodology: The surface of commercial activated carbon (CAC) was modified by using concentrated nitric acid. For this purpose, nitric acid in different concentrations (2, 4, 6, 8, and 10 M) and different temperatures (25, 50, 75, and 100( °C were used.Results and Discussion: The best results were observed at 50 °C in which it was used as a standard temperature. A 10 M nitric acid concentration was noticed as the best one. It could be observed that the high pore volume observed in modified activated carbon samples (estimated as the highest adsorption capacity towards iodine, using iodine number determination method) was (707.2 mg/g). This result was supported by methylene blue (190 mg/g). The modified activated carbon (MAC) at the chosen acid concentration was a useful filter to remove the methylene blue organic dye. The modified activated carbon (MAC) was used to adsorbed Pb 2+ ions from the Mosul Tigris river wastewaters, the percentage of mean changed activated carbon (MAC) surface adsorption removal efficiency of divalent lead ions were increased by 219% compared with the commercial activated carbon (CAC) Conclusions: : Using the methods for iodine number, ash content, methylene blue and density determinations, it was proven that the excellent sorption properties, strong microporous structure, large pore volume, surface of the acidic character, and porosity are the most critical chemical characterization parameters