Synthesis of new ammonium chitosan derivatives and their application for dye removal from aqueous media

Chitosan/gluteraldehyde resin was chemically modified using ammonium hydroxide to produce (RI) resin, which was additionally semi cross-linked with epichlorohydrine through hydroxyl group of chitosan. The obtained resin was modified with 3-Amino-1,2,4 triazole,5-thiol to produce resin (RII)/or melamine to produce resin (RIII). The uptake of modified chitosan resins toward Brilliant Blue R250 (BBR250) from aqueous media was studied using batch method. Various parameters such as pH, agitation time and temperature had been studied. The resins showed high affinity for the adsorption of BBR250 from aqueous media where uptake values of 0.97, 0.79 and 2.505 mmol/g were reported for resins RI, RII and RIII at 25 °C, respectively. Both kinetics and thermodynamic parameters of the process were estimated. These data indicated an endothermic spontaneous adsorption process and kinetically followed the pseudo-second order model, Fickian diffusion low and Elovich model. Desorption of BBR250 from the prepared resins was efficiently done using sodium hydroxide.

► New three modified ammonium chitosan resins were prepared and characterized.
► Adsorption of Brilliant Blue dye at different experimental conditions was studied.
► The kinetic and thermodynamic properties of the adsorption process were studied.
► The obtained resins showed high affinity for Brilliant Blue dye adsorption.
► The regeneration of the loaded resins for repeated use was studied.