Synthesis and characterization of cyclodextrin-based acrylamide polymer flocculant for adsorbing water-soluble dyes in dye wastewater

A novel hydrophobic and cationic cyclodextrin-based acrylamide flocculant (AM-β-CD-DMDAAC) was prepared by chemical oxidative polymerization to adsorb water-soluble dyes in dye wastewater. Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), scanning electron microscope (SEM), and thermogravimetric (TG) measurements results demonstrated that the AM-β-CD-DMDAAC was successfully synthesized. The effects of pH, contact time, initial dye concentration, temperature and adsorbent dose on dye removal efficiency for AM-β-CD-DMDAAC flocculants were investigated. The kinetic data were found to follow pseudo-second-order kinetic model. The equilibrium adsorption data were fitted to Langmuir isotherm model, with the adsorption capacity 147.1 mg/g. The adsorbent retained about 60 % of the adsorption efficiency after three adsorption/desorption cycles, which implied a promising application as the dye adsorbent.