Molybdenum (Mo) has wide applications in many pharmaceutical and biological areas 1. Mo is an economically important silvery-white transition metal and has five main oxidation states ranging from (+2) to (+6). It belongs to group 6 between chromium (Cr) and tungsten (W) in the periodic table with an atomic number of 42 and an atomic mass of 96 2,3. Mo is a bio-essential element for humans, animals, and plants that have relatively low toxicity because it is a component or co-factor of enzymes which are essential for life, so without Mo, organisms cannot function and will show signs of deficiency 4,5. Metallic Mo offers many advantages like good corrosion resistance, excellent mechanical, thermal, electrical properties, high temperature and melting point (2883 K) due to the low coefficient of its thermal expansion and a high thermal conductivity. These excellent properties make it be widely used in electronics, metallurgy, aerospace and electrical industries 6-8.
Biosorbent is a biological origin solid system from bacterial, fungal, plant or animal origin. It has different functional groups including carboxyl, ether, carbonyl, hydroxyl, and ester groups and more effective alternatives for sorption of metal ions (e.g Mo) from aqueous solution 9-12. Adsorption using a cheap, abundant and environmental-friendly adsorbent obtained from plant materials, for example, the olive tree is currently being researched as effective substitutes as is the simplest and most useful method 13, 14. Olive tree (Olea Europea) was one of the first small fruit domesticated trees in the family Oleaceae cultivated by man since more than 5500 years ago. Its common name was for about 35 species of evergreen shrubs and trees of the genus Olea in the in the olive family which has various parts (fruit, leaves, oil). Olive trees are found native to the Medial East, Egypt, Palestine, Jordon, Syria, Africa and Asia with many varieties that exhibit major or minor phenotypical and genetic differences 15-17.