[SYLWAN., 159(1)]. ISI Indexed 146 Assessment of Nickel(II) Removal From Aqueous Solution Using Saudi Bentonite Mohamed I. Attia 1 *, Omar K. Alduaij 1 and Lotfi Khezami 1 1 Department of Chemistry, Science College, Al Imam Mohammad Bin Saud Islamic University, (IMSIU), Riyadh, KSA *Corresponding Author: Mohamed I. Attia: P.O Box 90950 Riyadh 11623 KSA, Fax: +9662591678, Mobile : 00966532859145, e-mail:mohamedattia1@hotmail.com Abstract: ModeƌŶ IŶdustƌies’ efflueŶts cause wateƌ coŶtaŵiŶatioŶ with heavy metals. In this work, bentonite was used for nickel(II) removal from aqueous solution compared with commercial activated carbon. The adsorption isotherms (Langmuir, Freundlich, and Brauner-Emmett-Teller) were applied. The rate constant of adsorption, the rate constant for intraparticle diffusion, pore diffusion coefficient, overall reaction rate, equilibrium constant and the thermodynamic parameters ΔGᵒ, ΔHᵒ and ΔSᵒ were evaluated. Also the effect of time, Sorbent dose, initial concentration and the pH at different temperatures were studied. The results were promising, indicating that bentonite is capable of removing nickel(II) from aqueous solution. The equilibrium time for nickel(II) adsorption by bentonite is larger than that by the powdered activated carbon and highly pH dependent. The kinetics of adsorption were investigated as first order diffusion controlled and spontaneous process. Key words: Adsorption, Bentonite, Ni(II), Thermodynamic Functions, Activated Carbon, Kinetics. Introduction: * Funded project No. 331207/1433 H from the Deanship of Scientific Research at Al Imam Mohammad Bin Saud Islamic University, (IMSIU), Riyadh, KSA.