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, X-ray diffraction, scanning electron microscope 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 the pseudo-second-order kinetic model. The equilibrium adsorption data were fitted to the Langmuir isotherm model, with the maximum adsorption capacity of 147.1 mg g−1. The adsorbent retained about 60% of the adsorption efficiency after three adsorption/desorption cycles, which implied a promising application as the dye adsorbent.