An Insight Into The Adsorption Behavior of Malachite Green on DABCO (1,4-diazabicyclo[2.2.2]octane) Modified Bentonite

Organ modified bentonite was synthesized by replacing the exchangeable cation in the interlamellar space of ben- tonite with 1,4-diazabicyclo[2.2.2]cetane (DABCO). The modified bentonite product was systematically studied for its adsorption behavior for removal of Malachite Green (MG) dye from aqueous solution. The change of bentonite nature, before and after modification was characterized with X-Ray diffraction analysis and FT-IR spectroscopy technique. The behavior of MG adsorption on the adsorbent was investigated in batch experiment method. Some effect of the operational parameters, including adsorbent dosage, contact time, and initial dye concentration were investigated. The result indicated that the removal of MG on the modified bentonite occurred in fast process in which the adsorption equilibrium time was achieved only within 10 to 20 min. The kinetics adsorption study was conducted by employing two kinetics models named pseudo-first order and pseudo-second order kinetics model. The results showed that the adsorption kinetics of MG was well defined by using pseudo- second order model rather than the pseudo-first order model. The adsorption equilibrium of MG was also explored according to the Langmuir and Freundlich adsorption isotherm model. The employed data indicated that adsorption of MG on DABCO modified bentonite was better defined by Langmuir isotherm model.