4. Conclusions
Chitosan has potential as an adsorbent for removal of reactive
dyes from textile wastewater because it can adsorb
reactive dyes over a wide pH range and at high temperatures.
The effect of initial pH, elution studies, and the thermodynamic
parameters demonstrated that the reactive dye
was probably adsorbed onto chitosan by both physical and
chemical adsorption. In addition, the adsorption mechanism
under acidic conditions was chemical adsorption, while under
caustic conditions was both physical and chemical adsorption.
However, the ATR-FTIR spectra confirmed that the
amines on chitosan polymer tend to be effective functional
groups for dye adsorption under acidic conditions, while the
hydroxyl group tended to be the effective functional group
for dye adsorption under caustic conditions.