Marine green algae Ulva lactuca was used as an efficient, low cost and eco-friendly biosorbent for the removal of some heavy metal ions from an industrial drainage station of Petrochemicals Company. Temperature, pH, nitrates, orthophosphate, sulphates and heavy metals (Cd, Pb, Zn, Ni, Cr, Cu, Fe and Mn) were measured. The study revealed that the biosorption efficiency was 50% after 15min of water treatment by Ulva lactuca. While, after 60min, the efficiency reached a percentage of 95, and after 120 min, the efficiency rate remained stable or was slightly lower than that recorded for the 60min interval at a biomass weight of 1g/ L. In addition, the smallest size (0.063µm) was the most efficient to bind more metal ions by algal biomass with the best result, compared to the largest size (0.250µm) which showed the least efficiency for binding ions. It was deduced that 1g/ L of dry U. lactuca biomass at a size of 0.065 was found to successfully remove 90, 83.7, 98.1, and 93.1 for Cd, Fe, Pb and Ni, respectively, from aqueous solution.