TITLE:
Kinetic and Equilibrium Isotherms Studies of Adsorption of Pb(II) from Water onto Natural Adsorbent
AUTHORS:
Taha M. Elmorsi, Zeinhom H. Mohamed, Walied Shopak, Ahmed M. Ismaiel
KEYWORDS:
Dobera Leaves, Pb(II), Adsorption Kinetics, Adsorption Isotherms
JOURNAL NAME:
Journal of Environmental Protection,
Vol.5 No.17,
December
22,
2014
ABSTRACT: In this research dobera leaves (DL), an agricultural
waste, available in large quantity in south region of Saudi Arabia, were used
as low-cost adsorbent for removal of metal ions such as Pb(II). Batch operation
was used to study the equilibrium behavior of DL. The effects of initial
concentration of Pb(II), solution pH, contact time and adsorbent dose were
evaluated. To study the kinetics of adsorption of Pb(II) onto DL, pseudo-first-order,
pseudo-second-order and intra-particle diffusion were used. Adsorption process
undergoes pseudo-second-order kinetic as proved by the high value of R2. Furthermore, to design
the equilibrium data of adsorption of process, four adsorption isotherm models
such as Langmuir, Freundlich Temkin and Dubinin-Radushkevich (D-R) were used.
It is found that Langmuir equation has the highest value of R2 (0.999) compared with
other models. In presences of a mixture of Pb(II)/Ni(II), DL were found to be
selective for Pb(II) ions with a high adsorptive capacity of 83 mg/g and show
favorable adsorption with RL 90%)
from drinking water with less competition of other ions present in water.