Preparation of supported chitosan adsorbent with high adsorption capacity for Titan Yellow removal.

The supported chitosan (CS) adsorbent (FZCS) was successfully prepared by load CS on the BSCS supporter in this work. The adsorbent was characterized by elemental analysis, FT-IR, XRD, TGA, SEM and N2 adsorption-desorption techniques. The results showed the FZCS sorbent displayed the high removal rate (97.95%) for Titan Yellow (TY) anionic dye in aqueous solutions owing to its properties combining amino active functional amino group from the CS itself and higher specific surface area and mesoporous structure from the BSCS support. Isotherm data conform to the Langmuir isothermal model with a maximum adsorption capacity of 120.48 mg/g at 30 °C, suggesting monolayer adsorption of TY on the FZCS sorbent. The data were very well fitted to the pseudo-second-order kinetics. The adsorption capacity of FZCS could maintain about 70% after six cycles. The research indicated that FZCS would be a promising, eco-friendly and effective sorbent for anionic dye wastewater treatment in the near future.

Modification of chitin with high adsorption capacity for methylene blue removal.

Porous chitin sorbents (PChs) with different content of chitin, ranging from 0.9% to 3.5%, were prepared by gel method with CaBr2·xH2O/CH3OH solution and characterized by FT-IR, XRD and SEM. The adsorption isotherms and kinetic analysis of methylene blue (MB) onto PChs were studied. Experimental results illustrated lower crystallinity and more pores of PChs containing 3.5% chitin displayed higher adsorption capacity, the removal of MB was 79.8%. The adsorption equilibrium isotherm curve of MB onto PChs adsorbents conformed to the Freundlich equation. The PFO, PSO and Weber-Morris models were applied to fit with the adsorption kinetics. The results demonstrated the adsorption of MB might be the mass transfer of heterogeneous system and involve multiple diffusion steps. The adsorption capacity of PChs with 3.5% chitin can maintain 65% removal ratio of MB after being used six adsorption-desorption cycles. It was supposed that PChs may be a promising, cheap, environmentally friendly and efficient adsorbent for some dye wastewater treatment in the near future.