REMOVAL OF ACID BLUE 9, FOOD YELLOW 3 AND FD&C YELLOW N degrees 5 DYES FROM AQUEOUS SOLUTIONS USING ACTIVATED CARBON, ACTIVATED EARTH, DIATOMACEOUS EARTH, CHITIN AND CHITOSAN: EQUILIBRIUM STUDIES AND THERMODYNAMIC

REMOVAL OF ACID BLUE 9, FOOD YELLOW 3 AND FD&C YELLOW N degrees 5 DYES FROM AQUEOUS SOLUTIONS USING ACTIVATED CARBON, ACTIVATED EARTH, DIATOMACEOUS EARTH, CHITIN AND CHITOSAN: EQUILIBRIUM STUDIES AND THERMODYNAMIC. This work compared activated carbon, activated earth, diatomaceous earth, chitin and chitosan to removal acid blue 9, food yellow 3 and FD&C yellow n degrees 5 dyes from aqueous solutions with different pH values (2-10). In the best process condition for each dye, equilibrium studies were carried out at different temperatures (from 298 to 328 K) and Langmuir, Freundlich, Redlich-Peterson, Temkin and Dubinin-Radushkevich models were fitted with experimental data. In addition, entropy change, Gibbs free energy change and enthalpy change were obtained in order to verify the thermodynamic adsorption behavior.