Preparation and Characterization of Dabco (1,4-Diazabicyclo [2.2.2]octane) modified bentonite: Application for Congo red removal

Natural bentonite provided from Sarolangun deposit was modified with 1,4-Diazabicyclo [2.2.2]octane (Dabco) to form a new class of porous material. Prior further modification, the natural bentonite was cleaned up and activated by NaCl to remove the impurities and increase the bentonite nature. Dabco modified bentonite (Dabco-bent) was prepared by exchanging the inorganic cation placed in the interlayer space of the montmorillonite mineral structure with the 0.01 M Dabco(1+) at pH 6. The modified bentonite products were characterized using X-Ray powder diffraction and FT-IR to monitor the change of the bentonite crystallinity and function group due to the modification process. The XRD result confiuned that during the modification process, the d(001) of smectite peak at 2 theta around 6 degrees was shifted. After the modification, the d(001) reflection of the montmorillonite interlayer was shifted 0.36 degrees to the left indicating that the interlayer space of the montmorillonite has been expanded during the modification process. The FTIR spectra of Dabco modified bentonite exhibit no significantly different with the host bentonite. However, the presence of the new band at the wavenumber around 3000 and 2800 cm(-1) indicates that the Dabco molecule has been successfully inserted to the bentonite molecule. The Congo red adsorption experiment was perfouned onto Dabco-bent product by batch technique. The experiment data described that kinetic model for Congo red adsorption onto Dabco-bent was adequately followed the second- order kinetic model and well described by Freundlich adsorption isotherm model.