The preparation of titanium dioxide/palygorskite composite and its application in the adsorption of congo red.

Titanium dioxide/palygorskite (TiO₂/PA) was prepared by acid-catalyzed sol-gel method and the resulting composite was applied in the adsorption of anion dye, Congo red. The effects of various experimental parameters such as adsorbent dosage, contact time and initial dye concentration on adsorption were investigated in detail. The adsorption behaviors of TiO₂/PA composite showed that the adsorption kinetics and isotherms were in good agreement with the pseudo-second-order equation and the Langmuir model, respectively. And the maximum adsorption capacity of TiO₂/PA composite for Congo red calculated by the Langmuir model was 518.13 mg g⁻¹. Unlike conventional research on TiO₂-based material, in which TiO₂ was utilized as the photocatalyst for wastewater treatment. Here, the removal of Congo red was mainly due to the excellent adsorption capacity of PA and amorphous TiO₂. So the TiO₂/PA composite could be a promising adsorbent for anion dyes adsorption. © 2012 American Institute of Chemical Engineers Environ Prog, 32: 1090-1095, 2013 [ABSTRACT FROM AUTHOR]