Abstract
Chitosan hydrogels were modified with (NH 4 ) 2 SO 4 solution using two methods and were tested in adsorbing acid dyes at a high pH of 8.2. The modified chitosan presented significantly improved adsorption capacities toward two dye samples: acid orange 7 and acid red 18. Specifically, these capacities were about 7.4 and 14.4 times higher than those of native chitosan, respectively, at the same conditions. The ion-exchange mechanism of the dye adsorption on the modified sample was proposed and verified by FTIR spectra. Regeneration experiments showed that the dye exhausted sample can be almost completely regenerated with NaOH solution while the capacity was largely retained even after 20 cycles of adsorption-regeneration-modification processes.
Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
