BENTONIT TERMODIFIKASI CETILTRIMETILAMMONIUM UNTUK ADSORPSI ION Cu2+ DAN ZAT WARNA ANIONIK EOSIN

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