Adsorption study of Congo Red Dye with ZSM-5 directly synthesized from bangka kaolin withouth organic template

Abstract

ZSM-5’s adsorption study of kaolin Bangka without organic template using congo red with initial concentration of 50-250 mg / L with variation of contact time of 40-180 minutes. The results of the adsorption of Congo Red (CR) dye at 30oC-50oC with pH 7, the increase in contact time causes the dye to decrease significantly. In addition, an increase in adsorption rate at first step then slows down as it approaches to the equilibrium point. The experimental results using each temperature variation, showing the equilibrium time of the adsorption process at contact time of 100 minutes. Four isotherm adsorption models were used to analyze and measure the results of experimental data adsorption. The ZSM-5 adsorption capacity of Bangka kaolin is exhibited for the reds of Congo isotherm adsorption. The results of isotherm adsorption studies on three temperatures showed the fitting into Langmuir isotherms adsorption type which means the adsroption occured physically monolayer, the kinetics of adsorption clearly follows the first-pseudo-order reaction kinetics with higher R2 closes to 1. The adsorption thermodynamics analysis show that the adsorption chategorized as exthormic reaction (negative value of ), this conclusion is supported by adsortion capacity data in 180 min contact times which demostrate that the increasing adorption temperature decreasing amount adsorbate being adsorbed. The  (Gibb’s Energy) of adsorption are negative in several temperature which demonstrates that the adsroption are spontanously occured in ech temperature. The adsorption study can be used as a reference for ZSM-5 adsorption optimization.