title: The adsorption of Cu(II) ions on bentonite--a kinetic study.
abstract: The kinetics of sorption of Cu(2+) on a Saudi clay mineral (bentonite) was investigated at 20+/-0.5 degrees C using different weights of the clay (0.5, 1.0, 1.5, and 2 g). Each weight represents a certain sample size. The order of the process appeared to be 1 with respect to the Cu(2+), and 112 with respect to the clay surface area. The rate was found to depend on internal diffusion.,which produced a decrease in the specific rate of sorption as a function of time. Sorption characteristics were described using two site Langmuir isotherms. The desorption experiments proved that Cu(2+) ions are chemisorbed on the bentonite surface. The maximum adsorption obtained was 909 mg Cu(2+)/g clay. This value is of great significance, as it is much higher than any reported one.
authors.affiliation: Chemistry Department, College of Science, Women Student Medical Studies and Sciences Sections, King Saud University, P.O. Box 22452, Riyadh 11495, Saudi Arabia. maha@ksu.edu.sa
authors.forename: M H
authors.initials: MH
authors.lastname: Al-Qunaibit
authors.forename: W K
authors.initials: WK
authors.lastname: Mekhemer
authors.forename: A A
authors.initials: AA
authors.lastname: Zaghloul
mesh_terms: D000327:Adsorption; D001546:Bentonite / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D007700:Kinetics; D013499:Surface Properties
chemical_list: D001546:Bentonite; D003300:Copper