BENTONIT TERPILARISASI SENYAWA OKSIDA LOGAM Cr/Al DAN APLIKASINYA SEBAGAI PENYERAP ZAT WARNA CONGO RED DAN DIRECT BLUE

Pillarization of bentonite with metal oxide compounds Cr/Al by comparison 2:1 and 1:2 has been done. The result of bentonite pillarization with metal oxide Cr/Al was characterized with XRD and FT-IR Spectrophotometer. The result of characterization with XRD has shown the optimal pillarization process with comparison 2:1 with diffraction peak (2θ) 5,3° is 16,4 A. While comparison 1:2 has just shown diffraction peak (2θ) 6,4° is 13,7A. The research result of the characterization with FT-IR Spectrophotometer has not shown the optimal result. The result of optimal bentonite pillarization with comparison 2:1 was applied as adsorbent for congo red and direct blue. The process of adsorption was used Freundlich type. At congo red showed the adsorption rate (k) was 0,0017 min-1 and 0,0007 min-1 for direct blue adsorption. The largest adsorption capasity for congo red at 70°C was 48,31 mol/g and 69,4 mol/g for direct blue. The largest adsorption energy for congo red at 70°C is 63,98 kJ/mol and 30,88 kJ/mol for direct blue. The enthalpy value (ΔH) and the entropy (ΔS) increased with increasing the concentration of congo red and direct blue. The pH effect on adsorption had best affected on pH 2. The amount of adsorption level at pH 2 was 75,15 mg/L for natural bentonite and 88,9 mg/L for pillarization of bentonite Cr/Al for each adsorption congo red. The amount of adsorption level at pH 2 was 39,22 mg/L for natural bentonite and 89,05 mg/L for pillarization of bentonite Cr/Al for each adsorption direct blue.