| Summary: | Modification of natural bentonite with cethyltrimethylammonium bromide
(CTAB) for adsorption of cationic and anionic subtances has been studied. Cu
2+
ion
and eosin anionic dye were used as adsorbates in the research. The research was
started by washing natural bentonite using 1,5 M sulfuric acid then modified using
2 cation exchange capacity (CEC) CTAB. Material was characterized by FTIR
spectrometry and X-ray diffraction methods, meanwhile the adsorbed cation was
measured by AAS and anion by UV-Vis spectrophotometry. Result showed that the
major component of bentonite was montmorillonite. Acid activation caused
dealumination in bentonite structure. Cu
2+
was adsorbed in pH 2, while eosin dye
in pH 6. Adsorption of Cu
2+
and eosin anionic dye on CTA-bentonite followed a
Langmuir adsorption isotherm model. Adsorption capacity of Cu
2+
was 6,28 x 10
-5
mol/g and eosin dye with 0,57 x 10
-5
mol/g. Adsorption energy of Cu
2+
was 27,20
kJ/mol lower than eosin with 32,75 kJ/mol. Meanwhile, adsorption capability of
Cu
2+
on natural bentonite > activated bentonite > CTA-bentonite and natural
bentonite < activated bentonite < CTA-bentonite for eosin.
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