Fresenius Environ Bull, cilt.26, sa.4, ss.2721-2729, 2017 (SCI-Expanded)
This study presents the evaluation of the
original diatomite (DO) and manganese oxide
modified (DMn) diatomite used as adsorbents for Pb
(II) removal from aqueous solution. The
experimental data were fitted to the non-linear twoparameter equation of Langmuir, Freundlich,
Dubinin-Radushkevich, and non-linear threeparameter equation of Redlich-Peterson, Sips and
Toth Isotherms. The correlation coefficient (R2
),
standard error (S.E) and Chi-VTXDUHȤ2
) values were
used to select the best theoretical isotherm.
Adsorption mechanism of Pb(II) ion onto the DO was
explained by heterogeneous adsorption model while
homogenous adsorption model was used to explain
the adsorption on DMn. Also, both adsorbents were
observed to comply better with the three-parameter
isotherms. Pseudo first-order, pseudo second-order,
Elovich and intraparticle diffusion equations were
used to describe the adsorption rate of Pb(II). The
experimental data were well fitted by the pseudosecond-order kinetic model. Thermodynamic
SDUDPHWHUV VXFK DV IUHH HQHUJ\ ǻ*o
), enthalpy
ǻ+o
DQG HQWURS\ ǻ6o
) showed spontaneous and
endothermic in nature of adsorption for both of
adsorbents.