International Science Community Association Research Journal of Chemical Sciences 2231 - 606X 5 2 2015 February 18 Equilibrium and Thermodynamic Studies on Adsorption of Cd2+ and Zn2+ using Brachystegia eurycoma Seed coat as Biosorbent 32 41 EN Okechukwu R.I. 1 Department of Biological Sciences, Federal University of Technology, Owerri, Imo State, NIGERIA Iwuchukwu A.C. 2 Anuforo H.U. 3 Kumar D.Prem 1 Department of Chemistry, Sri Krishnadevaraya University, Anantapur–515 003, A.P., INDIA PraveenKumar A. 2 Reddy P.Raveendra 3 Yusuf A.J. 1 1 Department of Pharmaceutical and Medicinal Chemistry, Usmanu Danfodiyo University, Sokoto, NIGERIA Department of Pure and Applied Chemistry, Usmanu Danfodiyo University, Sokoto, NIGERIA Galadima A. 2 Garba 3 Z.N. 4 Nasir I. 5 Nirmala Baby 1 Department of Science and Humanities, Christian College of Engineering and Technology, Oddanchatram, Dindigul, Tamil Nadu, INDIA Manjula P. 2 Head, Department of Chemistry, APA College for Women, Palani, Dindigul, Tamil Nadu, INDIA Manimegalai S. 3 Department of Chemistry, APA College of Arts and Culture, Palani Dindigul, Tamil Nadu, INDIA ArthurRomuald Cakpo 1 Laboratoire de Chimie Inorganique et de l’Environnement (LaCIE), Faculté des Sciences et Techniques (FAST), Université d’Abomey -Calavi BP : 4521 Cotonou, République du BENIN Etienne Sagbo1 2 Laboratoire d’Hydrologie Appliquée (LHA), Université d’Abomey- Calavi, République du BENIN Daouda Mama 3 Laboratoire d’Etude et de Recherche en Chimie Appliquée (LERCA), Ecole polytechnique d’Abomey- Calavi (EPAC), Université etMohamedM. Soumanou 4 d’Abomey- Calavi, République du BENIN Davidenko O.A. 1 Chemical Department, Taras Shevchenko National University of Kyiv, 01601 Kyiv, UKRAINE SokolskyV. E. 2 The E.O. Paton Electric Welding Institute, National Academy of Sciences of Ukraine, 03680 Kyiv, UKRAINE LisnyakV. V. 3 RoikO. S. 4 Goncharov I.A. 5 GalinichV. I. 6 Onwu F.K 1 Department of Chemistry, Michael Okpara University of Agriculture Umudike, P.M.B 7267, Umuahia, Abia State, NIGERIA Ngele S.O. 2 Department of Industrial Chemistry, Ebonyi State University, P.M.B. 053 Abakaliki, NIGERIA > Research Paper 2015 1 12 2015 February 18 The potential of B.eurycoma seed coat as biosorbent for removing Cd2+ and Zn2+ from aqueous solutions has been studied. Batch adsorption experiments were carried out as function of pH, initial metal ion concentration and temperature. Maximum metal sorption was found to occur at pH 6.0 at initial concentration of 30 mg/L and at 30C. The maximum adsorption capacity of B.eurycoma corresponding to sites saturation was found to be 4.286 and 4.390 mg/g respectively for initial Cd2+and Zn2+ concentration of 30 mg/L at a temperature of 40 C. The results were analyzed by the Langmuir, Freundlich, Temkin and Dubinin–Radushkevich (D–R) isotherms using linearized correlation coefficient at different temperatures. Results showed that the Langmuir and Freundlich models gave the best interpretation to the equilibrium adsorption data for the Cd(II) and Zn(II) ions–B.eurycoma systems studied. The following thermodynamic parameters: H, S and G were calculated and results obtained showed that the adsorption process was exothermic and spontaneous. Copyright@ International Science Community Association