TITLE:
Sorption Kinetics, Isotherm and Thermodynamic Modeling of Defluoridation of Ground Water Using Natural Adsorbents
AUTHORS:
Aamna Balouch, Mazhar Kolachi, Farah Naz Talpur, Humaira Khan, Muhammad I. Bhanger
KEYWORDS:
Isotherm; Kinetics and Thermodynamic Modeling; Ground Water; Natural Adsorbent; Defluoridation
JOURNAL NAME:
American Journal of Analytical Chemistry,
Vol.4 No.5,
May
22,
2013
ABSTRACT: The aim of study is to investigate the removal ability
of some natural adsorbents for fluoride ion from aqueous solution. The batch
dynamic adsorption method was carried out at neutral pH as the functions of
contact time, adsorbent dose, adsorbate concentration, temperature and effect
of co-anions, which are commonly present in water. The sorption kinetics
and equilibrium adsorption isotherms of fluoride on natural adsorbing materials
had been investigated at afore-mentioned optimized. Equilibrium adsorption
isotherms, viz., Freundlich and Langmuir isotherms were investigated. Lagergren
and Morris-Weber kinetic equations were employed to find the rate constants.
The negative enthalpy ΔH = -46.54 KJ·mol-1 and Gibbs free energy calculated was ΔG288-333—(2.07785, 3.08966, 4.1064, 4.90716 and 5.38036 KJ·mol-1)
respectively, envisage exothermic and spontaneous nature of sorption.