Aquatic ecosystems may receive hazardous heavy metals resulting from the overconsumption of petrochemical products. Chemical and physical analysis of wastewater of certain petrochemical plants was studied; and pointed for the existence of Cd, Pb, Zn, Ni, Cu, Co, Fe and Mn. The objective of this work is to study the effectiveness of immobilized Scenedesmus obliquus to remove such pollutants. Both fresh and dry biomass of the micro-green alga S. obliquus in immobilized form was used as low cost, efficient, and eco-friendly biosorbent for some heavy metals' removal. According to the results, the biosorption removal efficiency in general with all heavy metals was around 50% after 15 min. of treatment, and it reached 95% after 60 min, while the efficiency rate remained stable or was slightly lowered after 120 min. Moreover, the cited results clarify that S. obliquus as biosorbent was more powerful in removing Pb, Cd and Fe followed by Ni, Cu, Mn, Co, and Zn from the aqueous solution of petrochemical wastewater. For further verification, at the end of the treatment process, the algae cells were examined under the scanning electron microscope (SEM), which showed large clusters of heavy metals appeared adsorbed on the surfaces of the cells, which reflects the high efficiency of S. obliquus in removing heavy metals from industrial wastewaters. These results motivate us to apply the use of live or dry algae mass as an effective and safe method for the disposal of heavy metals and industrial effluents.