Removal of astrazon golden yellow 7GL from colored wastewater using chemically modified clay

Abstract

Chemically modified clay (CMC) was used as an adsorbent for the removal of Astrazon Golden Yellow 7GL (AGY-7GL), which is a basic dye from wastewater. For this purpose, the chemically modified clay was first characterized by determining zero point of charge (pH(zpc)), and using BET, SEM and FTIR. Then effects of operational parameters on adsorption of AGY-7GL were studied in a batch system. The effect of various parameters such as contact time (0-180 min), pH (2-8), temperature (293-323 K), CMC concentration (0.075-0.5 mg/L) and initial AGY-7GL concentration (75-250 mg/L) were investigated on the adsorption efficiency and capacity adsorption of CMC for the removal of AGY-7GL. Thermodynamic and kinetic parameters were calculated from the results of the adsorption experiment. The evaluation of kinetic models shows that this data best fits the pseudo-second-order model. It is determined that the adsorption equilibrium data works very well with the nonlinear Freundlich isotherm model. Thermodynamic parameters such as Delta H (0) (19.0 kJ/mol), Delta G (0) (-28.8 kJ/mol) and Delta S (0) (0.148 kJ/mol) were also determined. According to the experimental results, it is concluded that CMC could be used as an alternative low cost potential adsorbent for the removal of AGY-7GL from wastewater.