The present work concerning with studying the potentiality of green algal biomasses namely Ulva lactuca (Linnaeus, marine green alga) and Cladophora glomerata (Linnaeus) Kützing (fresh water alga)to adsorb uranium from its processing effluents of Gattar Pilot Planet, Eastern Desert, Egypt. The maximum bio-sorption efficiency of uranium was achieved at 1 hr contact time, 1/1000 S/l ratio, 200 ppm uranium as initial concentration at pH 4 at the room temperature using the investigated two green algal biomasses. The optimal bio-sorption values were 147.5and 287.7mg/g for U. lactuca and C. glomerata respectively. The studied algae were characterized by SEM before and after uranium bio-sorption. These showed different morphological changes such as wrinkling, protuberance and roughness with uranium bio-sorption as well as each algal type had a unique surface structure in its raw form. FTIR was used to distinguish the contributing groups which were variable and involve several mechanisms depending on uranium and algal type. The obtained experimental kinetic data were pseudo-second-order after uranium bio-sorption on U. lactuca and C. glomerata. The Langmuir isotherm model more fits the data of uranium bio-sorption than the other models (Freundlich, D-R, and Temkin).These indicating that, uranium bio-sorption process on the two green algal masses is physico-chemical monolayer mechanism. The phytochemical analyses clarify the percentage of the main constituents of the algal biomasses as (10.9 and 12,63%) of phenol, (8.3 and 15.9%) of protein and (6 and 10.16%) of carbohydrates for both U. lactuca and C. glomerata respectively .The loaded uranium was efficiently eluted by 0.1 M HCl. By applying the two green algal biomasses with fixing the optimum concluded conditions in the treatment of Gatter pilot plant sample, almost of elements and nearly uranium complete concentrations were recovered from the waste water and the water can be safely reused again. However, the uranium was eluted from the concerned algae using 0.1 M HCl, while the other elements were eluted by 0.3 M EDTA and the uranium full recovery needs 3 separation cycles.