Adsorption of Allura Red with Zeolite Modified Polyacrylamide Composite

In the present work, the adsorption of allura red was studied with the zeolite modified polyacrylamide composite as the adsorbent combined with a UV-absorption spectrometry. Effects of sample pH and contact time on the adsorption rate were investigated. Kinetics, isotherms, and thermodynamics studies were conducted for the adsorption process. And the regeneration of adsorbent was carried out. The result showed that the adsorption equilibrium of allura red was reached after the contact time was 80 min at the sample pH of 6. The adsorption process of the zeolite modified polyacrylamide composite for allura red fitted the pseudo-second-order kinetic model (R²=0.9984) and Langmuir adsorption equation. When the temperature was 20℃, the changes of enthalpy (ΔH), entropy (ΔS), and Gibbs energy (ΔG) were 39.01 kJ/mol, 145.22 J/mol/K, and (4.23 kJ/mol, respectively. The adsorption capacity of allura red did not obviously changed after the regeneration of three times. The study proved that the zeolite modified polyacrylamide composite for allura red had good adsorbability and regeneration.