Applicability of the new material pyrolyzed
Delonix regia
pod carbon for the removal of excess fluoride
ions from the water that harm the human and the
environment was studied. The adsorbent was characterized
both physically and chemically. Surface chemistry characterization
was done with pH-drift method. Batch
adsorption studies were carried out for the effect of pH,
dosage, contact time, initial fluoride concentration, temperature
and interfering co-ions. The physicochemical
properties and textural characters were analyzed. Equilibrium
data were studied using Freundlich, Langmuir,
Temkin and Dubinin–Radushkevich models, in which
Freundlich isotherm was considered to be the best fit for
the adsorbent. The sorption nature was studied using
thermodynamic parameters which showed spontaneous,
irreversible, stable and endothermic. The adsorption
kinetics follows pseudo-second order. The mechanism of
adsorption was determined from intraparticle diffusion
model. Boyd plot showed that the adsorption of fluoride on
the carbon was mainly governed by particle diffusion.
