EN
Adsorption of reactive dyes and surfactants onto chitin from mixtures containing surfactants at constant concentration and dyes at variable concentration was investigated in the present study. Two vinylsulfonate dyes (Scarlet R, Brillantorange 3R); chlorotriazine dye (Black DN); anionic (Borutosol KRN, Siarczanol N-2) and non-ionic (Rokafenol N-8) surfactants were tested. The experiments were carried out without and with pH adjustment. The research have proved that at pH 6.2 and in surfactants presence the adsorption of vinyl-sulfonate dyes onto chitin was lower than without surfactants (control sample). It was observed that the maximum adsorption capacity of chitin in mixtures of Scarlet R and surfactants was about 3-fold lower than without surfactants and in mixtures of Brillantorange 3R and surfactants was from 2.5 to 4.1-fold lower than in control sample. At pH 3.0 the differences between maximum adsorption capacity of chitin for dyes from aqueous solutions and containing surfactants ranged from 2% (in mixture of Brillantorange 3R and Borutosol KRN) to 23% (in mixture of Scarlet R and Siarczanol N-2). The maximum adsorption capacity of chitin for Black DN (chlorotriazyne dye) in surfactants presence (from 140 to 290 mg/dm3 ) was higher at pH 6.2 as well as at pH 3.0 in comparison to control sample. Rokafenol N-8 was adsorbed the weakest onto chitin from among tested surfactants. At pH 3.0 for vinyl-sulfonate dyes the relationships between mass proportion of dye and surfactant adsorbed onto chitin (Qdye/QSAA* ) and initial concentration proportion of dye and surfactant in solution (Cdye/CSAA) was nearly linear. This indicates that dyes competed with surfactants of active sites of chitin. SAA* – Surface Active Agent (s)