**Removal of an Azo Textile Dye from Wastewater by Cyclodextrin-Epichlorohydrin Polymers Cyclodextrin-Epichlorohydrin Polymers**

**Removal of an Azo Textile Dye from Wastewater by** 

DOI: 10.5772/intechopen.72502

Paola Semeraro, José Antonio Gabaldón, Paola Fini, Estrella Núňez, José Antonio Pellicer, Vito Rizzi and Pinalysa Cosma Estrella Núňez, José Antonio Pellicer, Vito Rizzi and Pinalysa Cosma Additional information is available at the end of the chapter

Paola Semeraro, José Antonio Gabaldón, Paola Fini,

Additional information is available at the end of the chapter

http://dx.doi.org/10.5772/intechopen.72502

#### **Abstract**

Native cyclodextrins (CDs), α-, β- and γ-CDs, were employed to synthetise three different cyclodextrin-based polymers using epichlorohydrin (EPI) as a cross-linker. These polymers were applied as adsorbent material to remove an azo textile dye, Direct Blue 78 (DB78), from water. The formation of inclusion complexes between the alone CDs and DB78 molecules were first studied in aqueous solutions. Then, adsorption experiments of the dye were performed by means of cyclodextrin/epichlorohydrin (CD/EPI) polymers. The effects of various parameters, such as contact time, adsorbent dosage, initial dye concentration, pH and temperature, were examined to determine the better adsorption conditions. The equilibrium isotherms and the adsorption kinetics were also analysed using opportune mathematic models. The chemical-physical characteristics and the morphology of the adsorbent polymers were, respectively, observed by differential scanning calorimetry and field emission scanning electron microscope. The CD/EPI polymers showed a very good ability in the removal of DB78 from aqueous solution; indeed, the maximum efficiencies in the dye removal were found to be about 99% for β-CD/EPI polymer and about 97% for γ-CD/EPI polymer, at pH 6 and 25°C conditions. It is possible to assume that the good adsorbent aptitude of CD/EPI polymers is due to their double peculiarity to include the dye in the inner cavity of CDs and to adsorb the dye on their porous surfaces by physical interaction.

**Keywords:** inclusion complexes, electrochemical measurements, adsorption process, textile dye removal, cyclodextrin/epichlorohydrin polymers, thermal analysis

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© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons
