Sorbent Characteristics of Montmorillonite for Ni<sup>2+</sup> Removal
from Aqueous Solution

Ijagbemi, Christianah Olakitan; Kim, Dong-Su

doi:2009.14.1.26

Environmental Engineering Research 2009;14(1): 26-31. DOI: https://doi.org/10.4491/eer.2009.14.1.026

Sorbent Characteristics of Montmorillonite for Ni²⁺ Removal from Aqueous Solution

Christianah Olakitan Ijagbemi, and Dong-Su Kim^†

Environmental Science and Engineering, Ewha Womans University, Seoul, South Korea

Corresponding Author: Dong-Su Kim ,Tel: +82-2-3277-2394, Fax: +82-2-3277-3275, Email: dongsu@ewha.ac.kr

Received: August 7, 2008; Accepted: December 9, 2008.

ABSTRACT

Sorption of Ni²⁺ in aqueous solution was studied using montmorillonite. The experimental and equilibrium data fitted well to the Langmuir isotherm model. From the kinetics data for nickel sorption onto montmorillonite, the diffusion of Ni²⁺ inside the clay particles was the dorminant step controlling the sorption rate and as such more important for Ni²⁺ sorption than the external mass transfer. Ni²⁺ was sorbed due to strong interactions with the active sites of the sorbent and the sorption process tends to follow the pseudo second-order kinetics. Thermodynamic parameters (ΔG°, Δ H°, and ΔS°) indicated a non spontaneous and endothermic adsorption process while the positive low value of the entropy change suggests low randomness of the solid/solution interface during the uptake of Ni²⁺ by montmorilionite. Heavy metals such as Ni²⁺ in aqueous bodies can effectively be sorbed by montmorillonite.

Keywords: Montmorillonite | Nickel | Kinetics | Adsorption isotherms