Potentially toxic trace elements, such as zinc, with high levels in water pose very serious problems around the world. Adsorption process is among the most effective techniques for removing of many heavy metal ions from different types of water. In this study, an attempt has been made to investigate the efficiency of economically cheaper, easily available and renewable biomass of Neem (Azadirachta indica) leaves for zinc adsorption from aqueous solutions. Biomass carbon samples were prepared from the zero-cost biomass waste of neem leaves. During the removal process, the effects of solution pH, adsorbent dose, contact time, temperature and initial metal ion concentration on adsorption efficiency by Neem Leaf Carbon (NLC) were studied. Experimental equilibrium data were analyzed by the Langmuir and Freundlich isotherm models. The optimum conditions obtained were 30 min contact time, 0.8g adsorbent dose, 45 0C, 0.12M Zn and pH 7 for zinc removal. The equilibrium data fitted well to the Langmuir and Fruendlich adsorption model with correlation coefficient (R2) value of 0.992 and 0.961 respectively. The results revealed that zinc is considerably adsorbed on neem leaf derived carbon and it could be economic method for the removal of zinc from aqueous solutions.
