Adsorption of reactive Green 19 from water using Polyaniline/Bentonite

Polyaniline/bentonite was used in this study to investigate its adsorption behaviors of reactive green 19. Influencing factors including contact time, pH, temperature and inorganic salts were investigated. The adsorption kinetic data fitted the pseudo-second-order model better than the pseudo-first-order and Elovich models, and the Langmuir model was better than the Freundlich model to describe the adsorption process. Thermodynamic studies indicated that the adsorption of reactive green 19 by polyaniline/bentonite was an endothermic and spontaneous process. Experimental data indicated that both NaCl and Na2SO4 could improve the reactive green 19 adsorption as a result of aggregation of the dye molecules in solution induced by the inorganic salts, and increase of pH value from 5 to 9 caused a slight decrease of reactive green 19 adsorption.