Sorption of Phthalocyanine Dyes by Chitosan-Sulfate Particles Immobilized on a Fiber Substrate

Resumo

A new material resistant to acidic media to be used as a sorbent to remove anionic dyes from water has been developed by means of immobilization of chitosan-sulfate particles on a fiber substrate. Phthalocyanine dyes differing in molecular size, as well as quantity and nature of anion groups, were used as model sorbates. It has been established that the sorption rate and the limiting sorption capacity decrease along with an increase of the dyes’ molecular size. A conclusion has been drawn that the effect of solution pH on the sorption parameters is a combined result of changes in the degree of protonation of chitosan amino-groups and in the dyes’ state of association in the solution. The dyes’ experimental sorption isotherms were processed according to the Langmuir model with a correlation coefficient of 0.98–0.99. The new material has exhibited a sorption rate an order of magnitude higher than that of the initial chitosan in powder form, as well as almost twice the sorption capacity.